| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* SCTP kernel implementation |
| * (C) Copyright IBM Corp. 2001, 2004 |
| * Copyright (c) 1999-2000 Cisco, Inc. |
| * Copyright (c) 1999-2001 Motorola, Inc. |
| * Copyright (c) 2001-2002 Intel Corp. |
| * Copyright (c) 2002 Nokia Corp. |
| * |
| * This is part of the SCTP Linux Kernel Implementation. |
| * |
| * These are the state functions for the state machine. |
| * |
| * Please send any bug reports or fixes you make to the |
| * email address(es): |
| * lksctp developers <linux-sctp@vger.kernel.org> |
| * |
| * Written or modified by: |
| * La Monte H.P. Yarroll <piggy@acm.org> |
| * Karl Knutson <karl@athena.chicago.il.us> |
| * Mathew Kotowsky <kotowsky@sctp.org> |
| * Sridhar Samudrala <samudrala@us.ibm.com> |
| * Jon Grimm <jgrimm@us.ibm.com> |
| * Hui Huang <hui.huang@nokia.com> |
| * Dajiang Zhang <dajiang.zhang@nokia.com> |
| * Daisy Chang <daisyc@us.ibm.com> |
| * Ardelle Fan <ardelle.fan@intel.com> |
| * Ryan Layer <rmlayer@us.ibm.com> |
| * Kevin Gao <kevin.gao@intel.com> |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <linux/net.h> |
| #include <linux/inet.h> |
| #include <linux/slab.h> |
| #include <net/sock.h> |
| #include <net/inet_ecn.h> |
| #include <linux/skbuff.h> |
| #include <net/sctp/sctp.h> |
| #include <net/sctp/sm.h> |
| #include <net/sctp/structs.h> |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/sctp.h> |
| |
| static struct sctp_packet *sctp_abort_pkt_new( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| const void *payload, size_t paylen); |
| static int sctp_eat_data(const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands); |
| static struct sctp_packet *sctp_ootb_pkt_new( |
| struct net *net, |
| const struct sctp_association *asoc, |
| const struct sctp_chunk *chunk); |
| static void sctp_send_stale_cookie_err(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_chunk *err_chunk); |
| static enum sctp_disposition sctp_sf_do_5_2_6_stale( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| static enum sctp_disposition sctp_sf_shut_8_4_5( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| static enum sctp_disposition sctp_sf_tabort_8_4_8( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| static enum sctp_disposition sctp_sf_new_encap_port( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk); |
| |
| static enum sctp_disposition sctp_stop_t1_and_abort( |
| struct net *net, |
| struct sctp_cmd_seq *commands, |
| __be16 error, int sk_err, |
| const struct sctp_association *asoc, |
| struct sctp_transport *transport); |
| |
| static enum sctp_disposition sctp_sf_abort_violation( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| void *arg, |
| struct sctp_cmd_seq *commands, |
| const __u8 *payload, |
| const size_t paylen); |
| |
| static enum sctp_disposition sctp_sf_violation_chunklen( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| |
| static enum sctp_disposition sctp_sf_violation_paramlen( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, void *ext, |
| struct sctp_cmd_seq *commands); |
| |
| static enum sctp_disposition sctp_sf_violation_ctsn( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| |
| static enum sctp_disposition sctp_sf_violation_chunk( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| |
| static enum sctp_ierror sctp_sf_authenticate( |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk); |
| |
| static enum sctp_disposition __sctp_sf_do_9_1_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands); |
| |
| /* Small helper function that checks if the chunk length |
| * is of the appropriate length. The 'required_length' argument |
| * is set to be the size of a specific chunk we are testing. |
| * Return Values: true = Valid length |
| * false = Invalid length |
| * |
| */ |
| static inline bool sctp_chunk_length_valid(struct sctp_chunk *chunk, |
| __u16 required_length) |
| { |
| __u16 chunk_length = ntohs(chunk->chunk_hdr->length); |
| |
| /* Previously already marked? */ |
| if (unlikely(chunk->pdiscard)) |
| return false; |
| if (unlikely(chunk_length < required_length)) |
| return false; |
| |
| return true; |
| } |
| |
| /* Check for format error in an ABORT chunk */ |
| static inline bool sctp_err_chunk_valid(struct sctp_chunk *chunk) |
| { |
| struct sctp_errhdr *err; |
| |
| sctp_walk_errors(err, chunk->chunk_hdr); |
| |
| return (void *)err == (void *)chunk->chunk_end; |
| } |
| |
| /********************************************************** |
| * These are the state functions for handling chunk events. |
| **********************************************************/ |
| |
| /* |
| * Process the final SHUTDOWN COMPLETE. |
| * |
| * Section: 4 (C) (diagram), 9.2 |
| * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify |
| * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be |
| * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint |
| * should stop the T2-shutdown timer and remove all knowledge of the |
| * association (and thus the association enters the CLOSED state). |
| * |
| * Verification Tag: 8.5.1(C), sctpimpguide 2.41. |
| * C) Rules for packet carrying SHUTDOWN COMPLETE: |
| * ... |
| * - The receiver of a SHUTDOWN COMPLETE shall accept the packet |
| * if the Verification Tag field of the packet matches its own tag and |
| * the T bit is not set |
| * OR |
| * it is set to its peer's tag and the T bit is set in the Chunk |
| * Flags. |
| * Otherwise, the receiver MUST silently discard the packet |
| * and take no further action. An endpoint MUST ignore the |
| * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_4_C(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_ulpevent *ev; |
| |
| if (!sctp_vtag_verify_either(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* RFC 2960 6.10 Bundling |
| * |
| * An endpoint MUST NOT bundle INIT, INIT ACK or |
| * SHUTDOWN COMPLETE with any other chunks. |
| */ |
| if (!chunk->singleton) |
| return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* RFC 2960 10.2 SCTP-to-ULP |
| * |
| * H) SHUTDOWN COMPLETE notification |
| * |
| * When SCTP completes the shutdown procedures (section 9.2) this |
| * notification is passed to the upper layer. |
| */ |
| ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
| 0, 0, 0, NULL, GFP_ATOMIC); |
| if (ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| |
| /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint |
| * will verify that it is in SHUTDOWN-ACK-SENT state, if it is |
| * not the chunk should be discarded. If the endpoint is in |
| * the SHUTDOWN-ACK-SENT state the endpoint should stop the |
| * T2-shutdown timer and remove all knowledge of the |
| * association (and thus the association enters the CLOSED |
| * state). |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_CLOSED)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| /* |
| * Respond to a normal INIT chunk. |
| * We are the side that is being asked for an association. |
| * |
| * Section: 5.1 Normal Establishment of an Association, B |
| * B) "Z" shall respond immediately with an INIT ACK chunk. The |
| * destination IP address of the INIT ACK MUST be set to the source |
| * IP address of the INIT to which this INIT ACK is responding. In |
| * the response, besides filling in other parameters, "Z" must set the |
| * Verification Tag field to Tag_A, and also provide its own |
| * Verification Tag (Tag_Z) in the Initiate Tag field. |
| * |
| * Verification Tag: Must be 0. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg, *repl, *err_chunk; |
| struct sctp_unrecognized_param *unk_param; |
| struct sctp_association *new_asoc; |
| struct sctp_packet *packet; |
| int len; |
| |
| /* Update socket peer label if first association. */ |
| if (security_sctp_assoc_request((struct sctp_endpoint *)ep, |
| chunk->skb)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* 6.10 Bundling |
| * An endpoint MUST NOT bundle INIT, INIT ACK or |
| * SHUTDOWN COMPLETE with any other chunks. |
| * |
| * IG Section 2.11.2 |
| * Furthermore, we require that the receiver of an INIT chunk MUST |
| * enforce these rules by silently discarding an arriving packet |
| * with an INIT chunk that is bundled with other chunks. |
| */ |
| if (!chunk->singleton) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* If the packet is an OOTB packet which is temporarily on the |
| * control endpoint, respond with an ABORT. |
| */ |
| if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { |
| SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
| * Tag. |
| */ |
| if (chunk->sctp_hdr->vtag != 0) |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the INIT chunk has a valid length. |
| * Normally, this would cause an ABORT with a Protocol Violation |
| * error, but since we don't have an association, we'll |
| * just discard the packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* If the INIT is coming toward a closing socket, we'll send back |
| * and ABORT. Essentially, this catches the race of INIT being |
| * backloged to the socket at the same time as the user issues close(). |
| * Since the socket and all its associations are going away, we |
| * can treat this OOTB |
| */ |
| if (sctp_sstate(ep->base.sk, CLOSING)) |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| |
| /* Verify the INIT chunk before processing it. */ |
| err_chunk = NULL; |
| if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
| (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, |
| &err_chunk)) { |
| /* This chunk contains fatal error. It is to be discarded. |
| * Send an ABORT, with causes if there is any. |
| */ |
| if (err_chunk) { |
| packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
| (__u8 *)(err_chunk->chunk_hdr) + |
| sizeof(struct sctp_chunkhdr), |
| ntohs(err_chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr)); |
| |
| sctp_chunk_free(err_chunk); |
| |
| if (packet) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| return SCTP_DISPOSITION_CONSUME; |
| } else { |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| } else { |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, |
| commands); |
| } |
| } |
| |
| /* Grab the INIT header. */ |
| chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; |
| |
| /* Tag the variable length parameters. */ |
| chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); |
| |
| new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
| if (!new_asoc) |
| goto nomem; |
| |
| if (sctp_assoc_set_bind_addr_from_ep(new_asoc, |
| sctp_scope(sctp_source(chunk)), |
| GFP_ATOMIC) < 0) |
| goto nomem_init; |
| |
| /* The call, sctp_process_init(), can fail on memory allocation. */ |
| if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), |
| (struct sctp_init_chunk *)chunk->chunk_hdr, |
| GFP_ATOMIC)) |
| goto nomem_init; |
| |
| /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
| |
| /* If there are errors need to be reported for unknown parameters, |
| * make sure to reserve enough room in the INIT ACK for them. |
| */ |
| len = 0; |
| if (err_chunk) |
| len = ntohs(err_chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr); |
| |
| repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
| if (!repl) |
| goto nomem_init; |
| |
| /* If there are errors need to be reported for unknown parameters, |
| * include them in the outgoing INIT ACK as "Unrecognized parameter" |
| * parameter. |
| */ |
| if (err_chunk) { |
| /* Get the "Unrecognized parameter" parameter(s) out of the |
| * ERROR chunk generated by sctp_verify_init(). Since the |
| * error cause code for "unknown parameter" and the |
| * "Unrecognized parameter" type is the same, we can |
| * construct the parameters in INIT ACK by copying the |
| * ERROR causes over. |
| */ |
| unk_param = (struct sctp_unrecognized_param *) |
| ((__u8 *)(err_chunk->chunk_hdr) + |
| sizeof(struct sctp_chunkhdr)); |
| /* Replace the cause code with the "Unrecognized parameter" |
| * parameter type. |
| */ |
| sctp_addto_chunk(repl, len, unk_param); |
| sctp_chunk_free(err_chunk); |
| } |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| |
| /* |
| * Note: After sending out INIT ACK with the State Cookie parameter, |
| * "Z" MUST NOT allocate any resources, nor keep any states for the |
| * new association. Otherwise, "Z" will be vulnerable to resource |
| * attacks. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| |
| return SCTP_DISPOSITION_DELETE_TCB; |
| |
| nomem_init: |
| sctp_association_free(new_asoc); |
| nomem: |
| if (err_chunk) |
| sctp_chunk_free(err_chunk); |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Respond to a normal INIT ACK chunk. |
| * We are the side that is initiating the association. |
| * |
| * Section: 5.1 Normal Establishment of an Association, C |
| * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init |
| * timer and leave COOKIE-WAIT state. "A" shall then send the State |
| * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start |
| * the T1-cookie timer, and enter the COOKIE-ECHOED state. |
| * |
| * Note: The COOKIE ECHO chunk can be bundled with any pending outbound |
| * DATA chunks, but it MUST be the first chunk in the packet and |
| * until the COOKIE ACK is returned the sender MUST NOT send any |
| * other packets to the peer. |
| * |
| * Verification Tag: 3.3.3 |
| * If the value of the Initiate Tag in a received INIT ACK chunk is |
| * found to be 0, the receiver MUST treat it as an error and close the |
| * association by transmitting an ABORT. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_1C_ack(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_init_chunk *initchunk; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *err_chunk; |
| struct sctp_packet *packet; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* 6.10 Bundling |
| * An endpoint MUST NOT bundle INIT, INIT ACK or |
| * SHUTDOWN COMPLETE with any other chunks. |
| */ |
| if (!chunk->singleton) |
| return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the INIT-ACK chunk has a valid length */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_initack_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| /* Grab the INIT header. */ |
| chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; |
| |
| /* Verify the INIT chunk before processing it. */ |
| err_chunk = NULL; |
| if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
| (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, |
| &err_chunk)) { |
| |
| enum sctp_error error = SCTP_ERROR_NO_RESOURCE; |
| |
| /* This chunk contains fatal error. It is to be discarded. |
| * Send an ABORT, with causes. If there are no causes, |
| * then there wasn't enough memory. Just terminate |
| * the association. |
| */ |
| if (err_chunk) { |
| packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
| (__u8 *)(err_chunk->chunk_hdr) + |
| sizeof(struct sctp_chunkhdr), |
| ntohs(err_chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr)); |
| |
| sctp_chunk_free(err_chunk); |
| |
| if (packet) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| error = SCTP_ERROR_INV_PARAM; |
| } |
| } |
| |
| /* SCTP-AUTH, Section 6.3: |
| * It should be noted that if the receiver wants to tear |
| * down an association in an authenticated way only, the |
| * handling of malformed packets should not result in |
| * tearing down the association. |
| * |
| * This means that if we only want to abort associations |
| * in an authenticated way (i.e AUTH+ABORT), then we |
| * can't destroy this association just because the packet |
| * was malformed. |
| */ |
| if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, |
| asoc, chunk->transport); |
| } |
| |
| /* Tag the variable length parameters. Note that we never |
| * convert the parameters in an INIT chunk. |
| */ |
| chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); |
| |
| initchunk = (struct sctp_init_chunk *)chunk->chunk_hdr; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, |
| SCTP_PEER_INIT(initchunk)); |
| |
| /* Reset init error count upon receipt of INIT-ACK. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
| |
| /* 5.1 C) "A" shall stop the T1-init timer and leave |
| * COOKIE-WAIT state. "A" shall then ... start the T1-cookie |
| * timer, and enter the COOKIE-ECHOED state. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); |
| |
| /* SCTP-AUTH: generate the association shared keys so that |
| * we can potentially sign the COOKIE-ECHO. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL()); |
| |
| /* 5.1 C) "A" shall then send the State Cookie received in the |
| * INIT ACK chunk in a COOKIE ECHO chunk, ... |
| */ |
| /* If there is any errors to report, send the ERROR chunk generated |
| * for unknown parameters as well. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, |
| SCTP_CHUNK(err_chunk)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| static bool sctp_auth_chunk_verify(struct net *net, struct sctp_chunk *chunk, |
| const struct sctp_association *asoc) |
| { |
| struct sctp_chunk auth; |
| |
| if (!chunk->auth_chunk) |
| return true; |
| |
| /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo |
| * is supposed to be authenticated and we have to do delayed |
| * authentication. We've just recreated the association using |
| * the information in the cookie and now it's much easier to |
| * do the authentication. |
| */ |
| |
| /* Make sure that we and the peer are AUTH capable */ |
| if (!net->sctp.auth_enable || !asoc->peer.auth_capable) |
| return false; |
| |
| /* set-up our fake chunk so that we can process it */ |
| auth.skb = chunk->auth_chunk; |
| auth.asoc = chunk->asoc; |
| auth.sctp_hdr = chunk->sctp_hdr; |
| auth.chunk_hdr = (struct sctp_chunkhdr *) |
| skb_push(chunk->auth_chunk, |
| sizeof(struct sctp_chunkhdr)); |
| skb_pull(chunk->auth_chunk, sizeof(struct sctp_chunkhdr)); |
| auth.transport = chunk->transport; |
| |
| return sctp_sf_authenticate(asoc, &auth) == SCTP_IERROR_NO_ERROR; |
| } |
| |
| /* |
| * Respond to a normal COOKIE ECHO chunk. |
| * We are the side that is being asked for an association. |
| * |
| * Section: 5.1 Normal Establishment of an Association, D |
| * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply |
| * with a COOKIE ACK chunk after building a TCB and moving to |
| * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with |
| * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK |
| * chunk MUST be the first chunk in the packet. |
| * |
| * IMPLEMENTATION NOTE: An implementation may choose to send the |
| * Communication Up notification to the SCTP user upon reception |
| * of a valid COOKIE ECHO chunk. |
| * |
| * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
| * D) Rules for packet carrying a COOKIE ECHO |
| * |
| * - When sending a COOKIE ECHO, the endpoint MUST use the value of the |
| * Initial Tag received in the INIT ACK. |
| * |
| * - The receiver of a COOKIE ECHO follows the procedures in Section 5. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL; |
| struct sctp_association *new_asoc; |
| struct sctp_init_chunk *peer_init; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *err_chk_p; |
| struct sctp_chunk *repl; |
| struct sock *sk; |
| int error = 0; |
| |
| /* If the packet is an OOTB packet which is temporarily on the |
| * control endpoint, respond with an ABORT. |
| */ |
| if (ep == sctp_sk(net->sctp.ctl_sock)->ep) { |
| SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* Make sure that the COOKIE_ECHO chunk has a valid length. |
| * In this case, we check that we have enough for at least a |
| * chunk header. More detailed verification is done |
| * in sctp_unpack_cookie(). |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* If the endpoint is not listening or if the number of associations |
| * on the TCP-style socket exceed the max backlog, respond with an |
| * ABORT. |
| */ |
| sk = ep->base.sk; |
| if (!sctp_sstate(sk, LISTENING) || |
| (sctp_style(sk, TCP) && sk_acceptq_is_full(sk))) |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| |
| /* "Decode" the chunk. We have no optional parameters so we |
| * are in good shape. |
| */ |
| chunk->subh.cookie_hdr = |
| (struct sctp_signed_cookie *)chunk->skb->data; |
| if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr))) |
| goto nomem; |
| |
| /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint |
| * "Z" will reply with a COOKIE ACK chunk after building a TCB |
| * and moving to the ESTABLISHED state. |
| */ |
| new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
| &err_chk_p); |
| |
| /* FIXME: |
| * If the re-build failed, what is the proper error path |
| * from here? |
| * |
| * [We should abort the association. --piggy] |
| */ |
| if (!new_asoc) { |
| /* FIXME: Several errors are possible. A bad cookie should |
| * be silently discarded, but think about logging it too. |
| */ |
| switch (error) { |
| case -SCTP_IERROR_NOMEM: |
| goto nomem; |
| |
| case -SCTP_IERROR_STALE_COOKIE: |
| sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, |
| err_chk_p); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| case -SCTP_IERROR_BAD_SIG: |
| default: |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| } |
| |
| |
| /* Delay state machine commands until later. |
| * |
| * Re-build the bind address for the association is done in |
| * the sctp_unpack_cookie() already. |
| */ |
| /* This is a brand-new association, so these are not yet side |
| * effects--it is safe to run them here. |
| */ |
| peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| |
| if (!sctp_process_init(new_asoc, chunk, |
| &chunk->subh.cookie_hdr->c.peer_addr, |
| peer_init, GFP_ATOMIC)) |
| goto nomem_init; |
| |
| /* SCTP-AUTH: Now that we've populate required fields in |
| * sctp_process_init, set up the association shared keys as |
| * necessary so that we can potentially authenticate the ACK |
| */ |
| error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC); |
| if (error) |
| goto nomem_init; |
| |
| if (!sctp_auth_chunk_verify(net, chunk, new_asoc)) { |
| sctp_association_free(new_asoc); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| repl = sctp_make_cookie_ack(new_asoc, chunk); |
| if (!repl) |
| goto nomem_init; |
| |
| /* RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * D) IMPLEMENTATION NOTE: An implementation may choose to |
| * send the Communication Up notification to the SCTP user |
| * upon reception of a valid COOKIE ECHO chunk. |
| */ |
| ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, |
| new_asoc->c.sinit_num_ostreams, |
| new_asoc->c.sinit_max_instreams, |
| NULL, GFP_ATOMIC); |
| if (!ev) |
| goto nomem_ev; |
| |
| /* Sockets API Draft Section 5.3.1.6 |
| * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| * delivers this notification to inform the application that of the |
| * peers requested adaptation layer. |
| */ |
| if (new_asoc->peer.adaptation_ind) { |
| ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc, |
| GFP_ATOMIC); |
| if (!ai_ev) |
| goto nomem_aiev; |
| } |
| |
| if (!new_asoc->peer.auth_capable) { |
| auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0, |
| SCTP_AUTH_NO_AUTH, |
| GFP_ATOMIC); |
| if (!auth_ev) |
| goto nomem_authev; |
| } |
| |
| /* Add all the state machine commands now since we've created |
| * everything. This way we don't introduce memory corruptions |
| * during side-effect processing and correctly count established |
| * associations. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
| SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| |
| if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| |
| /* This will send the COOKIE ACK */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| |
| /* Queue the ASSOC_CHANGE event */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| |
| /* Send up the Adaptation Layer Indication event */ |
| if (ai_ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ai_ev)); |
| |
| if (auth_ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(auth_ev)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem_authev: |
| sctp_ulpevent_free(ai_ev); |
| nomem_aiev: |
| sctp_ulpevent_free(ev); |
| nomem_ev: |
| sctp_chunk_free(repl); |
| nomem_init: |
| sctp_association_free(new_asoc); |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Respond to a normal COOKIE ACK chunk. |
| * We are the side that is asking for an association. |
| * |
| * RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the |
| * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie |
| * timer. It may also notify its ULP about the successful |
| * establishment of the association with a Communication Up |
| * notification (see Section 10). |
| * |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_ulpevent *ev; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Verify that the chunk length for the COOKIE-ACK is OK. |
| * If we don't do this, any bundled chunks may be junked. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Reset init error count upon receipt of COOKIE-ACK, |
| * to avoid problems with the management of this |
| * counter in stale cookie situations when a transition back |
| * from the COOKIE-ECHOED state to the COOKIE-WAIT |
| * state is performed. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
| |
| /* Set peer label for connection. */ |
| security_inet_conn_established(ep->base.sk, chunk->skb); |
| |
| /* RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * E) Upon reception of the COOKIE ACK, endpoint "A" will move |
| * from the COOKIE-ECHOED state to the ESTABLISHED state, |
| * stopping the T1-cookie timer. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
| SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| |
| /* It may also notify its ULP about the successful |
| * establishment of the association with a Communication Up |
| * notification (see Section 10). |
| */ |
| ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, |
| 0, asoc->c.sinit_num_ostreams, |
| asoc->c.sinit_max_instreams, |
| NULL, GFP_ATOMIC); |
| |
| if (!ev) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| |
| /* Sockets API Draft Section 5.3.1.6 |
| * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| * delivers this notification to inform the application that of the |
| * peers requested adaptation layer. |
| */ |
| if (asoc->peer.adaptation_ind) { |
| ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); |
| if (!ev) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| } |
| |
| if (!asoc->peer.auth_capable) { |
| ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, |
| GFP_ATOMIC); |
| if (!ev) |
| goto nomem; |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Generate and sendout a heartbeat packet. */ |
| static enum sctp_disposition sctp_sf_heartbeat( |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_transport *transport = (struct sctp_transport *) arg; |
| struct sctp_chunk *reply; |
| |
| /* Send a heartbeat to our peer. */ |
| reply = sctp_make_heartbeat(asoc, transport, 0); |
| if (!reply) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* Set rto_pending indicating that an RTT measurement |
| * is started with this heartbeat chunk. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, |
| SCTP_TRANSPORT(transport)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* Generate a HEARTBEAT packet on the given transport. */ |
| enum sctp_disposition sctp_sf_sendbeat_8_3(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_transport *transport = (struct sctp_transport *) arg; |
| |
| if (asoc->overall_error_count >= asoc->max_retrans) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| /* Section 3.3.5. |
| * The Sender-specific Heartbeat Info field should normally include |
| * information about the sender's current time when this HEARTBEAT |
| * chunk is sent and the destination transport address to which this |
| * HEARTBEAT is sent (see Section 8.3). |
| */ |
| |
| if (transport->param_flags & SPP_HB_ENABLE) { |
| if (SCTP_DISPOSITION_NOMEM == |
| sctp_sf_heartbeat(ep, asoc, type, arg, |
| commands)) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* Set transport error counter and association error counter |
| * when sending heartbeat. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, |
| SCTP_TRANSPORT(transport)); |
| } |
| sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE, |
| SCTP_TRANSPORT(transport)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, |
| SCTP_TRANSPORT(transport)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* resend asoc strreset_chunk. */ |
| enum sctp_disposition sctp_sf_send_reconf(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_transport *transport = arg; |
| |
| if (asoc->overall_error_count >= asoc->max_retrans) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| sctp_chunk_hold(asoc->strreset_chunk); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(asoc->strreset_chunk)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* send hb chunk with padding for PLPMUTD. */ |
| enum sctp_disposition sctp_sf_send_probe(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_transport *transport = (struct sctp_transport *)arg; |
| struct sctp_chunk *reply; |
| |
| if (!sctp_transport_pl_enabled(transport)) |
| return SCTP_DISPOSITION_CONSUME; |
| |
| if (sctp_transport_pl_send(transport)) { |
| reply = sctp_make_heartbeat(asoc, transport, transport->pl.probe_size); |
| if (!reply) |
| return SCTP_DISPOSITION_NOMEM; |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| } |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROBE_TIMER_UPDATE, |
| SCTP_TRANSPORT(transport)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Process an heartbeat request. |
| * |
| * Section: 8.3 Path Heartbeat |
| * The receiver of the HEARTBEAT should immediately respond with a |
| * HEARTBEAT ACK that contains the Heartbeat Information field copied |
| * from the received HEARTBEAT chunk. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * When receiving an SCTP packet, the endpoint MUST ensure that the |
| * value in the Verification Tag field of the received SCTP packet |
| * matches its own Tag. If the received Verification Tag value does not |
| * match the receiver's own tag value, the receiver shall silently |
| * discard the packet and shall not process it any further except for |
| * those cases listed in Section 8.5.1 below. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_beat_8_3(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| struct sctp_paramhdr *param_hdr; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *reply; |
| size_t paylen = 0; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the HEARTBEAT chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, |
| sizeof(struct sctp_heartbeat_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* 8.3 The receiver of the HEARTBEAT should immediately |
| * respond with a HEARTBEAT ACK that contains the Heartbeat |
| * Information field copied from the received HEARTBEAT chunk. |
| */ |
| chunk->subh.hb_hdr = (struct sctp_heartbeathdr *)chunk->skb->data; |
| param_hdr = (struct sctp_paramhdr *)chunk->subh.hb_hdr; |
| paylen = ntohs(chunk->chunk_hdr->length) - sizeof(struct sctp_chunkhdr); |
| |
| if (ntohs(param_hdr->length) > paylen) |
| return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
| param_hdr, commands); |
| |
| if (!pskb_pull(chunk->skb, paylen)) |
| goto nomem; |
| |
| reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen); |
| if (!reply) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Process the returning HEARTBEAT ACK. |
| * |
| * Section: 8.3 Path Heartbeat |
| * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT |
| * should clear the error counter of the destination transport |
| * address to which the HEARTBEAT was sent, and mark the destination |
| * transport address as active if it is not so marked. The endpoint may |
| * optionally report to the upper layer when an inactive destination |
| * address is marked as active due to the reception of the latest |
| * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also |
| * clear the association overall error count as well (as defined |
| * in section 8.1). |
| * |
| * The receiver of the HEARTBEAT ACK should also perform an RTT |
| * measurement for that destination transport address using the time |
| * value carried in the HEARTBEAT ACK chunk. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_backbeat_8_3(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_sender_hb_info *hbinfo; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_transport *link; |
| unsigned long max_interval; |
| union sctp_addr from_addr; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr) + |
| sizeof(*hbinfo))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data; |
| /* Make sure that the length of the parameter is what we expect */ |
| if (ntohs(hbinfo->param_hdr.length) != sizeof(*hbinfo)) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| from_addr = hbinfo->daddr; |
| link = sctp_assoc_lookup_paddr(asoc, &from_addr); |
| |
| /* This should never happen, but lets log it if so. */ |
| if (unlikely(!link)) { |
| if (from_addr.sa.sa_family == AF_INET6) { |
| net_warn_ratelimited("%s association %p could not find address %pI6\n", |
| __func__, |
| asoc, |
| &from_addr.v6.sin6_addr); |
| } else { |
| net_warn_ratelimited("%s association %p could not find address %pI4\n", |
| __func__, |
| asoc, |
| &from_addr.v4.sin_addr.s_addr); |
| } |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* Validate the 64-bit random nonce. */ |
| if (hbinfo->hb_nonce != link->hb_nonce) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| if (hbinfo->probe_size) { |
| if (hbinfo->probe_size != link->pl.probe_size || |
| !sctp_transport_pl_enabled(link)) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| if (sctp_transport_pl_recv(link)) |
| return SCTP_DISPOSITION_CONSUME; |
| |
| return sctp_sf_send_probe(net, ep, asoc, type, link, commands); |
| } |
| |
| max_interval = link->hbinterval + link->rto; |
| |
| /* Check if the timestamp looks valid. */ |
| if (time_after(hbinfo->sent_at, jiffies) || |
| time_after(jiffies, hbinfo->sent_at + max_interval)) { |
| pr_debug("%s: HEARTBEAT ACK with invalid timestamp received " |
| "for transport:%p\n", __func__, link); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of |
| * the HEARTBEAT should clear the error counter of the |
| * destination transport address to which the HEARTBEAT was |
| * sent and mark the destination transport address as active if |
| * it is not so marked. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* Helper function to send out an abort for the restart |
| * condition. |
| */ |
| static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa, |
| struct sctp_chunk *init, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); |
| union sctp_addr_param *addrparm; |
| struct sctp_errhdr *errhdr; |
| char buffer[sizeof(*errhdr) + sizeof(*addrparm)]; |
| struct sctp_endpoint *ep; |
| struct sctp_packet *pkt; |
| int len; |
| |
| /* Build the error on the stack. We are way to malloc crazy |
| * throughout the code today. |
| */ |
| errhdr = (struct sctp_errhdr *)buffer; |
| addrparm = (union sctp_addr_param *)errhdr->variable; |
| |
| /* Copy into a parm format. */ |
| len = af->to_addr_param(ssa, addrparm); |
| len += sizeof(*errhdr); |
| |
| errhdr->cause = SCTP_ERROR_RESTART; |
| errhdr->length = htons(len); |
| |
| /* Assign to the control socket. */ |
| ep = sctp_sk(net->sctp.ctl_sock)->ep; |
| |
| /* Association is NULL since this may be a restart attack and we |
| * want to send back the attacker's vtag. |
| */ |
| pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len); |
| |
| if (!pkt) |
| goto out; |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| /* Discard the rest of the inbound packet. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| |
| out: |
| /* Even if there is no memory, treat as a failure so |
| * the packet will get dropped. |
| */ |
| return 0; |
| } |
| |
| static bool list_has_sctp_addr(const struct list_head *list, |
| union sctp_addr *ipaddr) |
| { |
| struct sctp_transport *addr; |
| |
| list_for_each_entry(addr, list, transports) { |
| if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr)) |
| return true; |
| } |
| |
| return false; |
| } |
| /* A restart is occurring, check to make sure no new addresses |
| * are being added as we may be under a takeover attack. |
| */ |
| static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *init, |
| struct sctp_cmd_seq *commands) |
| { |
| struct net *net = new_asoc->base.net; |
| struct sctp_transport *new_addr; |
| int ret = 1; |
| |
| /* Implementor's Guide - Section 5.2.2 |
| * ... |
| * Before responding the endpoint MUST check to see if the |
| * unexpected INIT adds new addresses to the association. If new |
| * addresses are added to the association, the endpoint MUST respond |
| * with an ABORT.. |
| */ |
| |
| /* Search through all current addresses and make sure |
| * we aren't adding any new ones. |
| */ |
| list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list, |
| transports) { |
| if (!list_has_sctp_addr(&asoc->peer.transport_addr_list, |
| &new_addr->ipaddr)) { |
| sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init, |
| commands); |
| ret = 0; |
| break; |
| } |
| } |
| |
| /* Return success if all addresses were found. */ |
| return ret; |
| } |
| |
| /* Populate the verification/tie tags based on overlapping INIT |
| * scenario. |
| * |
| * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. |
| */ |
| static void sctp_tietags_populate(struct sctp_association *new_asoc, |
| const struct sctp_association *asoc) |
| { |
| switch (asoc->state) { |
| |
| /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ |
| |
| case SCTP_STATE_COOKIE_WAIT: |
| new_asoc->c.my_vtag = asoc->c.my_vtag; |
| new_asoc->c.my_ttag = asoc->c.my_vtag; |
| new_asoc->c.peer_ttag = 0; |
| break; |
| |
| case SCTP_STATE_COOKIE_ECHOED: |
| new_asoc->c.my_vtag = asoc->c.my_vtag; |
| new_asoc->c.my_ttag = asoc->c.my_vtag; |
| new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
| break; |
| |
| /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, |
| * COOKIE-WAIT and SHUTDOWN-ACK-SENT |
| */ |
| default: |
| new_asoc->c.my_ttag = asoc->c.my_vtag; |
| new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
| break; |
| } |
| |
| /* Other parameters for the endpoint SHOULD be copied from the |
| * existing parameters of the association (e.g. number of |
| * outbound streams) into the INIT ACK and cookie. |
| */ |
| new_asoc->rwnd = asoc->rwnd; |
| new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; |
| new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; |
| new_asoc->c.initial_tsn = asoc->c.initial_tsn; |
| } |
| |
| /* |
| * Compare vtag/tietag values to determine unexpected COOKIE-ECHO |
| * handling action. |
| * |
| * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. |
| * |
| * Returns value representing action to be taken. These action values |
| * correspond to Action/Description values in RFC 2960, Table 2. |
| */ |
| static char sctp_tietags_compare(struct sctp_association *new_asoc, |
| const struct sctp_association *asoc) |
| { |
| /* In this case, the peer may have restarted. */ |
| if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
| (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && |
| (asoc->c.my_vtag == new_asoc->c.my_ttag) && |
| (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) |
| return 'A'; |
| |
| /* Collision case B. */ |
| if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
| ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || |
| (0 == asoc->c.peer_vtag))) { |
| return 'B'; |
| } |
| |
| /* Collision case D. */ |
| if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
| (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) |
| return 'D'; |
| |
| /* Collision case C. */ |
| if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
| (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && |
| (0 == new_asoc->c.my_ttag) && |
| (0 == new_asoc->c.peer_ttag)) |
| return 'C'; |
| |
| /* No match to any of the special cases; discard this packet. */ |
| return 'E'; |
| } |
| |
| /* Common helper routine for both duplicate and simultaneous INIT |
| * chunk handling. |
| */ |
| static enum sctp_disposition sctp_sf_do_unexpected_init( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg, *repl, *err_chunk; |
| struct sctp_unrecognized_param *unk_param; |
| struct sctp_association *new_asoc; |
| enum sctp_disposition retval; |
| struct sctp_packet *packet; |
| int len; |
| |
| /* Update socket peer label if first association. */ |
| if (security_sctp_assoc_request((struct sctp_endpoint *)ep, |
| chunk->skb)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* 6.10 Bundling |
| * An endpoint MUST NOT bundle INIT, INIT ACK or |
| * SHUTDOWN COMPLETE with any other chunks. |
| * |
| * IG Section 2.11.2 |
| * Furthermore, we require that the receiver of an INIT chunk MUST |
| * enforce these rules by silently discarding an arriving packet |
| * with an INIT chunk that is bundled with other chunks. |
| */ |
| if (!chunk->singleton) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
| * Tag. |
| */ |
| if (chunk->sctp_hdr->vtag != 0) |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the INIT chunk has a valid length. |
| * In this case, we generate a protocol violation since we have |
| * an association established. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| if (SCTP_INPUT_CB(chunk->skb)->encap_port != chunk->transport->encap_port) |
| return sctp_sf_new_encap_port(net, ep, asoc, type, arg, commands); |
| |
| /* Grab the INIT header. */ |
| chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data; |
| |
| /* Tag the variable length parameters. */ |
| chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr)); |
| |
| /* Verify the INIT chunk before processing it. */ |
| err_chunk = NULL; |
| if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type, |
| (struct sctp_init_chunk *)chunk->chunk_hdr, chunk, |
| &err_chunk)) { |
| /* This chunk contains fatal error. It is to be discarded. |
| * Send an ABORT, with causes if there is any. |
| */ |
| if (err_chunk) { |
| packet = sctp_abort_pkt_new(net, ep, asoc, arg, |
| (__u8 *)(err_chunk->chunk_hdr) + |
| sizeof(struct sctp_chunkhdr), |
| ntohs(err_chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr)); |
| |
| if (packet) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| retval = SCTP_DISPOSITION_CONSUME; |
| } else { |
| retval = SCTP_DISPOSITION_NOMEM; |
| } |
| goto cleanup; |
| } else { |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, |
| commands); |
| } |
| } |
| |
| /* |
| * Other parameters for the endpoint SHOULD be copied from the |
| * existing parameters of the association (e.g. number of |
| * outbound streams) into the INIT ACK and cookie. |
| * FIXME: We are copying parameters from the endpoint not the |
| * association. |
| */ |
| new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
| if (!new_asoc) |
| goto nomem; |
| |
| if (sctp_assoc_set_bind_addr_from_ep(new_asoc, |
| sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0) |
| goto nomem; |
| |
| /* In the outbound INIT ACK the endpoint MUST copy its current |
| * Verification Tag and Peers Verification tag into a reserved |
| * place (local tie-tag and per tie-tag) within the state cookie. |
| */ |
| if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), |
| (struct sctp_init_chunk *)chunk->chunk_hdr, |
| GFP_ATOMIC)) |
| goto nomem; |
| |
| /* Make sure no new addresses are being added during the |
| * restart. Do not do this check for COOKIE-WAIT state, |
| * since there are no peer addresses to check against. |
| * Upon return an ABORT will have been sent if needed. |
| */ |
| if (!sctp_state(asoc, COOKIE_WAIT)) { |
| if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, |
| commands)) { |
| retval = SCTP_DISPOSITION_CONSUME; |
| goto nomem_retval; |
| } |
| } |
| |
| sctp_tietags_populate(new_asoc, asoc); |
| |
| /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
| |
| /* If there are errors need to be reported for unknown parameters, |
| * make sure to reserve enough room in the INIT ACK for them. |
| */ |
| len = 0; |
| if (err_chunk) { |
| len = ntohs(err_chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr); |
| } |
| |
| repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
| if (!repl) |
| goto nomem; |
| |
| /* If there are errors need to be reported for unknown parameters, |
| * include them in the outgoing INIT ACK as "Unrecognized parameter" |
| * parameter. |
| */ |
| if (err_chunk) { |
| /* Get the "Unrecognized parameter" parameter(s) out of the |
| * ERROR chunk generated by sctp_verify_init(). Since the |
| * error cause code for "unknown parameter" and the |
| * "Unrecognized parameter" type is the same, we can |
| * construct the parameters in INIT ACK by copying the |
| * ERROR causes over. |
| */ |
| unk_param = (struct sctp_unrecognized_param *) |
| ((__u8 *)(err_chunk->chunk_hdr) + |
| sizeof(struct sctp_chunkhdr)); |
| /* Replace the cause code with the "Unrecognized parameter" |
| * parameter type. |
| */ |
| sctp_addto_chunk(repl, len, unk_param); |
| } |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| |
| /* |
| * Note: After sending out INIT ACK with the State Cookie parameter, |
| * "Z" MUST NOT allocate any resources for this new association. |
| * Otherwise, "Z" will be vulnerable to resource attacks. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| retval = SCTP_DISPOSITION_CONSUME; |
| |
| return retval; |
| |
| nomem: |
| retval = SCTP_DISPOSITION_NOMEM; |
| nomem_retval: |
| if (new_asoc) |
| sctp_association_free(new_asoc); |
| cleanup: |
| if (err_chunk) |
| sctp_chunk_free(err_chunk); |
| return retval; |
| } |
| |
| /* |
| * Handle simultaneous INIT. |
| * This means we started an INIT and then we got an INIT request from |
| * our peer. |
| * |
| * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) |
| * This usually indicates an initialization collision, i.e., each |
| * endpoint is attempting, at about the same time, to establish an |
| * association with the other endpoint. |
| * |
| * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an |
| * endpoint MUST respond with an INIT ACK using the same parameters it |
| * sent in its original INIT chunk (including its Verification Tag, |
| * unchanged). These original parameters are combined with those from the |
| * newly received INIT chunk. The endpoint shall also generate a State |
| * Cookie with the INIT ACK. The endpoint uses the parameters sent in its |
| * INIT to calculate the State Cookie. |
| * |
| * After that, the endpoint MUST NOT change its state, the T1-init |
| * timer shall be left running and the corresponding TCB MUST NOT be |
| * destroyed. The normal procedures for handling State Cookies when |
| * a TCB exists will resolve the duplicate INITs to a single association. |
| * |
| * For an endpoint that is in the COOKIE-ECHOED state it MUST populate |
| * its Tie-Tags with the Tag information of itself and its peer (see |
| * section 5.2.2 for a description of the Tie-Tags). |
| * |
| * Verification Tag: Not explicit, but an INIT can not have a valid |
| * verification tag, so we skip the check. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_2_1_siminit( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* Call helper to do the real work for both simultaneous and |
| * duplicate INIT chunk handling. |
| */ |
| return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Handle duplicated INIT messages. These are usually delayed |
| * restransmissions. |
| * |
| * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, |
| * COOKIE-ECHOED and COOKIE-WAIT |
| * |
| * Unless otherwise stated, upon reception of an unexpected INIT for |
| * this association, the endpoint shall generate an INIT ACK with a |
| * State Cookie. In the outbound INIT ACK the endpoint MUST copy its |
| * current Verification Tag and peer's Verification Tag into a reserved |
| * place within the state cookie. We shall refer to these locations as |
| * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet |
| * containing this INIT ACK MUST carry a Verification Tag value equal to |
| * the Initiation Tag found in the unexpected INIT. And the INIT ACK |
| * MUST contain a new Initiation Tag (randomly generated see Section |
| * 5.3.1). Other parameters for the endpoint SHOULD be copied from the |
| * existing parameters of the association (e.g. number of outbound |
| * streams) into the INIT ACK and cookie. |
| * |
| * After sending out the INIT ACK, the endpoint shall take no further |
| * actions, i.e., the existing association, including its current state, |
| * and the corresponding TCB MUST NOT be changed. |
| * |
| * Note: Only when a TCB exists and the association is not in a COOKIE- |
| * WAIT state are the Tie-Tags populated. For a normal association INIT |
| * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be |
| * set to 0 (indicating that no previous TCB existed). The INIT ACK and |
| * State Cookie are populated as specified in section 5.2.1. |
| * |
| * Verification Tag: Not specified, but an INIT has no way of knowing |
| * what the verification tag could be, so we ignore it. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_2_2_dupinit( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* Call helper to do the real work for both simultaneous and |
| * duplicate INIT chunk handling. |
| */ |
| return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands); |
| } |
| |
| |
| /* |
| * Unexpected INIT-ACK handler. |
| * |
| * Section 5.2.3 |
| * If an INIT ACK received by an endpoint in any state other than the |
| * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk. |
| * An unexpected INIT ACK usually indicates the processing of an old or |
| * duplicated INIT chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_2_3_initack( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* Per the above section, we'll discard the chunk if we have an |
| * endpoint. If this is an OOTB INIT-ACK, treat it as such. |
| */ |
| if (ep == sctp_sk(net->sctp.ctl_sock)->ep) |
| return sctp_sf_ootb(net, ep, asoc, type, arg, commands); |
| else |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
| } |
| |
| static int sctp_sf_do_assoc_update(struct sctp_association *asoc, |
| struct sctp_association *new, |
| struct sctp_cmd_seq *cmds) |
| { |
| struct net *net = asoc->base.net; |
| struct sctp_chunk *abort; |
| |
| if (!sctp_assoc_update(asoc, new)) |
| return 0; |
| |
| abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr)); |
| if (abort) { |
| sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); |
| sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| } |
| sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_RSRC_LOW)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| |
| return -ENOMEM; |
| } |
| |
| /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') |
| * |
| * Section 5.2.4 |
| * A) In this case, the peer may have restarted. |
| */ |
| static enum sctp_disposition sctp_sf_do_dupcook_a( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_association *new_asoc) |
| { |
| struct sctp_init_chunk *peer_init; |
| enum sctp_disposition disposition; |
| struct sctp_ulpevent *ev; |
| struct sctp_chunk *repl; |
| struct sctp_chunk *err; |
| |
| /* new_asoc is a brand-new association, so these are not yet |
| * side effects--it is safe to run them here. |
| */ |
| peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| |
| if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, |
| GFP_ATOMIC)) |
| goto nomem; |
| |
| if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC)) |
| goto nomem; |
| |
| if (!sctp_auth_chunk_verify(net, chunk, new_asoc)) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| /* Make sure no new addresses are being added during the |
| * restart. Though this is a pretty complicated attack |
| * since you'd have to get inside the cookie. |
| */ |
| if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) |
| return SCTP_DISPOSITION_CONSUME; |
| |
| /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes |
| * the peer has restarted (Action A), it MUST NOT setup a new |
| * association but instead resend the SHUTDOWN ACK and send an ERROR |
| * chunk with a "Cookie Received while Shutting Down" error cause to |
| * its peer. |
| */ |
| if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { |
| disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc, |
| SCTP_ST_CHUNK(chunk->chunk_hdr->type), |
| chunk, commands); |
| if (SCTP_DISPOSITION_NOMEM == disposition) |
| goto nomem; |
| |
| err = sctp_make_op_error(asoc, chunk, |
| SCTP_ERROR_COOKIE_IN_SHUTDOWN, |
| NULL, 0, 0); |
| if (err) |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked |
| * data. Consider the optional choice of resending of this data. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); |
| |
| /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue |
| * and ASCONF-ACK cache. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL()); |
| |
| /* Update the content of current association. */ |
| if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands)) |
| goto nomem; |
| |
| repl = sctp_make_cookie_ack(asoc, chunk); |
| if (!repl) |
| goto nomem; |
| |
| /* Report association restart to upper layer. */ |
| ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, |
| asoc->c.sinit_num_ostreams, |
| asoc->c.sinit_max_instreams, |
| NULL, GFP_ATOMIC); |
| if (!ev) |
| goto nomem_ev; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| if ((sctp_state(asoc, SHUTDOWN_PENDING) || |
| sctp_state(asoc, SHUTDOWN_SENT)) && |
| (sctp_sstate(asoc->base.sk, CLOSING) || |
| sock_flag(asoc->base.sk, SOCK_DEAD))) { |
| /* If the socket has been closed by user, don't |
| * transition to ESTABLISHED. Instead trigger SHUTDOWN |
| * bundled with COOKIE_ACK. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| return sctp_sf_do_9_2_start_shutdown(net, ep, asoc, |
| SCTP_ST_CHUNK(0), repl, |
| commands); |
| } else { |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| } |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem_ev: |
| sctp_chunk_free(repl); |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') |
| * |
| * Section 5.2.4 |
| * B) In this case, both sides may be attempting to start an association |
| * at about the same time but the peer endpoint started its INIT |
| * after responding to the local endpoint's INIT |
| */ |
| /* This case represents an initialization collision. */ |
| static enum sctp_disposition sctp_sf_do_dupcook_b( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_association *new_asoc) |
| { |
| struct sctp_init_chunk *peer_init; |
| struct sctp_chunk *repl; |
| |
| /* new_asoc is a brand-new association, so these are not yet |
| * side effects--it is safe to run them here. |
| */ |
| peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init, |
| GFP_ATOMIC)) |
| goto nomem; |
| |
| if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC)) |
| goto nomem; |
| |
| if (!sctp_auth_chunk_verify(net, chunk, new_asoc)) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| if (asoc->state < SCTP_STATE_ESTABLISHED) |
| SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| |
| /* Update the content of current association. */ |
| if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands)) |
| goto nomem; |
| |
| repl = sctp_make_cookie_ack(asoc, chunk); |
| if (!repl) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| |
| /* RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * D) IMPLEMENTATION NOTE: An implementation may choose to |
| * send the Communication Up notification to the SCTP user |
| * upon reception of a valid COOKIE ECHO chunk. |
| * |
| * Sadly, this needs to be implemented as a side-effect, because |
| * we are not guaranteed to have set the association id of the real |
| * association and so these notifications need to be delayed until |
| * the association id is allocated. |
| */ |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP)); |
| |
| /* Sockets API Draft Section 5.3.1.6 |
| * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| * delivers this notification to inform the application that of the |
| * peers requested adaptation layer. |
| * |
| * This also needs to be done as a side effect for the same reason as |
| * above. |
| */ |
| if (asoc->peer.adaptation_ind) |
| sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL()); |
| |
| if (!asoc->peer.auth_capable) |
| sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL()); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') |
| * |
| * Section 5.2.4 |
| * C) In this case, the local endpoint's cookie has arrived late. |
| * Before it arrived, the local endpoint sent an INIT and received an |
| * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag |
| * but a new tag of its own. |
| */ |
| /* This case represents an initialization collision. */ |
| static enum sctp_disposition sctp_sf_do_dupcook_c( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_association *new_asoc) |
| { |
| /* The cookie should be silently discarded. |
| * The endpoint SHOULD NOT change states and should leave |
| * any timers running. |
| */ |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') |
| * |
| * Section 5.2.4 |
| * |
| * D) When both local and remote tags match the endpoint should always |
| * enter the ESTABLISHED state, if it has not already done so. |
| */ |
| /* This case represents an initialization collision. */ |
| static enum sctp_disposition sctp_sf_do_dupcook_d( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_association *new_asoc) |
| { |
| struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL; |
| struct sctp_chunk *repl; |
| |
| /* Clarification from Implementor's Guide: |
| * D) When both local and remote tags match the endpoint should |
| * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. |
| * It should stop any cookie timer that may be running and send |
| * a COOKIE ACK. |
| */ |
| |
| if (!sctp_auth_chunk_verify(net, chunk, asoc)) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| /* Don't accidentally move back into established state. */ |
| if (asoc->state < SCTP_STATE_ESTABLISHED) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, |
| SCTP_NULL()); |
| |
| /* RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * D) IMPLEMENTATION NOTE: An implementation may choose |
| * to send the Communication Up notification to the |
| * SCTP user upon reception of a valid COOKIE |
| * ECHO chunk. |
| */ |
| ev = sctp_ulpevent_make_assoc_change(asoc, 0, |
| SCTP_COMM_UP, 0, |
| asoc->c.sinit_num_ostreams, |
| asoc->c.sinit_max_instreams, |
| NULL, GFP_ATOMIC); |
| if (!ev) |
| goto nomem; |
| |
| /* Sockets API Draft Section 5.3.1.6 |
| * When a peer sends a Adaptation Layer Indication parameter, |
| * SCTP delivers this notification to inform the application |
| * that of the peers requested adaptation layer. |
| */ |
| if (asoc->peer.adaptation_ind) { |
| ai_ev = sctp_ulpevent_make_adaptation_indication(asoc, |
| GFP_ATOMIC); |
| if (!ai_ev) |
| goto nomem; |
| |
| } |
| |
| if (!asoc->peer.auth_capable) { |
| auth_ev = sctp_ulpevent_make_authkey(asoc, 0, |
| SCTP_AUTH_NO_AUTH, |
| GFP_ATOMIC); |
| if (!auth_ev) |
| goto nomem; |
| } |
| } |
| |
| repl = sctp_make_cookie_ack(asoc, chunk); |
| if (!repl) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| |
| if (ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| if (ai_ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ai_ev)); |
| if (auth_ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(auth_ev)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| if (auth_ev) |
| sctp_ulpevent_free(auth_ev); |
| if (ai_ev) |
| sctp_ulpevent_free(ai_ev); |
| if (ev) |
| sctp_ulpevent_free(ev); |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying |
| * chunk was retransmitted and then delayed in the network. |
| * |
| * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists |
| * |
| * Verification Tag: None. Do cookie validation. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_5_2_4_dupcook( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_association *new_asoc; |
| struct sctp_chunk *chunk = arg; |
| enum sctp_disposition retval; |
| struct sctp_chunk *err_chk_p; |
| int error = 0; |
| char action; |
| |
| /* Make sure that the chunk has a valid length from the protocol |
| * perspective. In this case check to make sure we have at least |
| * enough for the chunk header. Cookie length verification is |
| * done later. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* "Decode" the chunk. We have no optional parameters so we |
| * are in good shape. |
| */ |
| chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; |
| if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
| sizeof(struct sctp_chunkhdr))) |
| goto nomem; |
| |
| /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie |
| * of a duplicate COOKIE ECHO match the Verification Tags of the |
| * current association, consider the State Cookie valid even if |
| * the lifespan is exceeded. |
| */ |
| new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
| &err_chk_p); |
| |
| /* FIXME: |
| * If the re-build failed, what is the proper error path |
| * from here? |
| * |
| * [We should abort the association. --piggy] |
| */ |
| if (!new_asoc) { |
| /* FIXME: Several errors are possible. A bad cookie should |
| * be silently discarded, but think about logging it too. |
| */ |
| switch (error) { |
| case -SCTP_IERROR_NOMEM: |
| goto nomem; |
| |
| case -SCTP_IERROR_STALE_COOKIE: |
| sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands, |
| err_chk_p); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| case -SCTP_IERROR_BAD_SIG: |
| default: |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| } |
| |
| /* Update socket peer label if first association. */ |
| if (security_sctp_assoc_request((struct sctp_endpoint *)ep, |
| chunk->skb)) { |
| sctp_association_free(new_asoc); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* Set temp so that it won't be added into hashtable */ |
| new_asoc->temp = 1; |
| |
| /* Compare the tie_tag in cookie with the verification tag of |
| * current association. |
| */ |
| action = sctp_tietags_compare(new_asoc, asoc); |
| |
| switch (action) { |
| case 'A': /* Association restart. */ |
| retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands, |
| new_asoc); |
| break; |
| |
| case 'B': /* Collision case B. */ |
| retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands, |
| new_asoc); |
| break; |
| |
| case 'C': /* Collision case C. */ |
| retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands, |
| new_asoc); |
| break; |
| |
| case 'D': /* Collision case D. */ |
| retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands, |
| new_asoc); |
| break; |
| |
| default: /* Discard packet for all others. */ |
| retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| break; |
| } |
| |
| /* Delete the temporary new association. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| |
| /* Restore association pointer to provide SCTP command interpreter |
| * with a valid context in case it needs to manipulate |
| * the queues */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, |
| SCTP_ASOC((struct sctp_association *)asoc)); |
| |
| return retval; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Process an ABORT. (SHUTDOWN-PENDING state) |
| * |
| * See sctp_sf_do_9_1_abort(). |
| */ |
| enum sctp_disposition sctp_sf_shutdown_pending_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| if (!sctp_vtag_verify_either(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ABORT chunk has a valid length. |
| * Since this is an ABORT chunk, we have to discard it |
| * because of the following text: |
| * RFC 2960, Section 3.3.7 |
| * If an endpoint receives an ABORT with a format error or for an |
| * association that doesn't exist, it MUST silently discard it. |
| * Because the length is "invalid", we can't really discard just |
| * as we do not know its true length. So, to be safe, discard the |
| * packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* ADD-IP: Special case for ABORT chunks |
| * F4) One special consideration is that ABORT Chunks arriving |
| * destined to the IP address being deleted MUST be |
| * ignored (see Section 5.3.1 for further details). |
| */ |
| if (SCTP_ADDR_DEL == |
| sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_err_chunk_valid(chunk)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Process an ABORT. (SHUTDOWN-SENT state) |
| * |
| * See sctp_sf_do_9_1_abort(). |
| */ |
| enum sctp_disposition sctp_sf_shutdown_sent_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| if (!sctp_vtag_verify_either(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ABORT chunk has a valid length. |
| * Since this is an ABORT chunk, we have to discard it |
| * because of the following text: |
| * RFC 2960, Section 3.3.7 |
| * If an endpoint receives an ABORT with a format error or for an |
| * association that doesn't exist, it MUST silently discard it. |
| * Because the length is "invalid", we can't really discard just |
| * as we do not know its true length. So, to be safe, discard the |
| * packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* ADD-IP: Special case for ABORT chunks |
| * F4) One special consideration is that ABORT Chunks arriving |
| * destined to the IP address being deleted MUST be |
| * ignored (see Section 5.3.1 for further details). |
| */ |
| if (SCTP_ADDR_DEL == |
| sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_err_chunk_valid(chunk)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Stop the T2-shutdown timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| /* Stop the T5-shutdown guard timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Process an ABORT. (SHUTDOWN-ACK-SENT state) |
| * |
| * See sctp_sf_do_9_1_abort(). |
| */ |
| enum sctp_disposition sctp_sf_shutdown_ack_sent_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* The same T2 timer, so we should be able to use |
| * common function with the SHUTDOWN-SENT state. |
| */ |
| return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Handle an Error received in COOKIE_ECHOED state. |
| * |
| * Only handle the error type of stale COOKIE Error, the other errors will |
| * be ignored. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_cookie_echoed_err( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_errhdr *err; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ERROR chunk has a valid length. |
| * The parameter walking depends on this as well. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Process the error here */ |
| /* FUTURE FIXME: When PR-SCTP related and other optional |
| * parms are emitted, this will have to change to handle multiple |
| * errors. |
| */ |
| sctp_walk_errors(err, chunk->chunk_hdr) { |
| if (SCTP_ERROR_STALE_COOKIE == err->cause) |
| return sctp_sf_do_5_2_6_stale(net, ep, asoc, type, |
| arg, commands); |
| } |
| |
| /* It is possible to have malformed error causes, and that |
| * will cause us to end the walk early. However, since |
| * we are discarding the packet, there should be no adverse |
| * affects. |
| */ |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Handle a Stale COOKIE Error |
| * |
| * Section: 5.2.6 Handle Stale COOKIE Error |
| * If the association is in the COOKIE-ECHOED state, the endpoint may elect |
| * one of the following three alternatives. |
| * ... |
| * 3) Send a new INIT chunk to the endpoint, adding a Cookie |
| * Preservative parameter requesting an extension to the lifetime of |
| * the State Cookie. When calculating the time extension, an |
| * implementation SHOULD use the RTT information measured based on the |
| * previous COOKIE ECHO / ERROR exchange, and should add no more |
| * than 1 second beyond the measured RTT, due to long State Cookie |
| * lifetimes making the endpoint more subject to a replay attack. |
| * |
| * Verification Tag: Not explicit, but safe to ignore. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| static enum sctp_disposition sctp_sf_do_5_2_6_stale( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| int attempts = asoc->init_err_counter + 1; |
| struct sctp_chunk *chunk = arg, *reply; |
| struct sctp_cookie_preserve_param bht; |
| struct sctp_bind_addr *bp; |
| struct sctp_errhdr *err; |
| u32 stale; |
| |
| if (attempts > asoc->max_init_attempts) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(SCTP_ERROR_STALE_COOKIE)); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| err = (struct sctp_errhdr *)(chunk->skb->data); |
| |
| /* When calculating the time extension, an implementation |
| * SHOULD use the RTT information measured based on the |
| * previous COOKIE ECHO / ERROR exchange, and should add no |
| * more than 1 second beyond the measured RTT, due to long |
| * State Cookie lifetimes making the endpoint more subject to |
| * a replay attack. |
| * Measure of Staleness's unit is usec. (1/1000000 sec) |
| * Suggested Cookie Life-span Increment's unit is msec. |
| * (1/1000 sec) |
| * In general, if you use the suggested cookie life, the value |
| * found in the field of measure of staleness should be doubled |
| * to give ample time to retransmit the new cookie and thus |
| * yield a higher probability of success on the reattempt. |
| */ |
| stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err))); |
| stale = (stale * 2) / 1000; |
| |
| bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; |
| bht.param_hdr.length = htons(sizeof(bht)); |
| bht.lifespan_increment = htonl(stale); |
| |
| /* Build that new INIT chunk. */ |
| bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
| reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); |
| if (!reply) |
| goto nomem; |
| |
| sctp_addto_chunk(reply, sizeof(bht), &bht); |
| |
| /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); |
| |
| /* Stop pending T3-rtx and heartbeat timers */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| |
| /* Delete non-primary peer ip addresses since we are transitioning |
| * back to the COOKIE-WAIT state |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); |
| |
| /* If we've sent any data bundled with COOKIE-ECHO we will need to |
| * resend |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN, |
| SCTP_TRANSPORT(asoc->peer.primary_path)); |
| |
| /* Cast away the const modifier, as we want to just |
| * rerun it through as a sideffect. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL()); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Process an ABORT. |
| * |
| * Section: 9.1 |
| * After checking the Verification Tag, the receiving endpoint shall |
| * remove the association from its record, and shall report the |
| * termination to its upper layer. |
| * |
| * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
| * B) Rules for packet carrying ABORT: |
| * |
| * - The endpoint shall always fill in the Verification Tag field of the |
| * outbound packet with the destination endpoint's tag value if it |
| * is known. |
| * |
| * - If the ABORT is sent in response to an OOTB packet, the endpoint |
| * MUST follow the procedure described in Section 8.4. |
| * |
| * - The receiver MUST accept the packet if the Verification Tag |
| * matches either its own tag, OR the tag of its peer. Otherwise, the |
| * receiver MUST silently discard the packet and take no further |
| * action. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_9_1_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| if (!sctp_vtag_verify_either(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ABORT chunk has a valid length. |
| * Since this is an ABORT chunk, we have to discard it |
| * because of the following text: |
| * RFC 2960, Section 3.3.7 |
| * If an endpoint receives an ABORT with a format error or for an |
| * association that doesn't exist, it MUST silently discard it. |
| * Because the length is "invalid", we can't really discard just |
| * as we do not know its true length. So, to be safe, discard the |
| * packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* ADD-IP: Special case for ABORT chunks |
| * F4) One special consideration is that ABORT Chunks arriving |
| * destined to the IP address being deleted MUST be |
| * ignored (see Section 5.3.1 for further details). |
| */ |
| if (SCTP_ADDR_DEL == |
| sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_err_chunk_valid(chunk)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| static enum sctp_disposition __sctp_sf_do_9_1_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| __be16 error = SCTP_ERROR_NO_ERROR; |
| struct sctp_chunk *chunk = arg; |
| unsigned int len; |
| |
| /* See if we have an error cause code in the chunk. */ |
| len = ntohs(chunk->chunk_hdr->length); |
| if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
| error = ((struct sctp_errhdr *)chunk->skb->data)->cause; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET)); |
| /* ASSOC_FAILED will DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| /* |
| * Process an ABORT. (COOKIE-WAIT state) |
| * |
| * See sctp_sf_do_9_1_abort() above. |
| */ |
| enum sctp_disposition sctp_sf_cookie_wait_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| __be16 error = SCTP_ERROR_NO_ERROR; |
| struct sctp_chunk *chunk = arg; |
| unsigned int len; |
| |
| if (!sctp_vtag_verify_either(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ABORT chunk has a valid length. |
| * Since this is an ABORT chunk, we have to discard it |
| * because of the following text: |
| * RFC 2960, Section 3.3.7 |
| * If an endpoint receives an ABORT with a format error or for an |
| * association that doesn't exist, it MUST silently discard it. |
| * Because the length is "invalid", we can't really discard just |
| * as we do not know its true length. So, to be safe, discard the |
| * packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* See if we have an error cause code in the chunk. */ |
| len = ntohs(chunk->chunk_hdr->length); |
| if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
| error = ((struct sctp_errhdr *)chunk->skb->data)->cause; |
| |
| return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc, |
| chunk->transport); |
| } |
| |
| /* |
| * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) |
| */ |
| enum sctp_disposition sctp_sf_cookie_wait_icmp_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR, |
| ENOPROTOOPT, asoc, |
| (struct sctp_transport *)arg); |
| } |
| |
| /* |
| * Process an ABORT. (COOKIE-ECHOED state) |
| */ |
| enum sctp_disposition sctp_sf_cookie_echoed_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* There is a single T1 timer, so we should be able to use |
| * common function with the COOKIE-WAIT state. |
| */ |
| return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Stop T1 timer and abort association with "INIT failed". |
| * |
| * This is common code called by several sctp_sf_*_abort() functions above. |
| */ |
| static enum sctp_disposition sctp_stop_t1_and_abort( |
| struct net *net, |
| struct sctp_cmd_seq *commands, |
| __be16 error, int sk_err, |
| const struct sctp_association *asoc, |
| struct sctp_transport *transport) |
| { |
| pr_debug("%s: ABORT received (INIT)\n", __func__); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_CLOSED)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err)); |
| /* CMD_INIT_FAILED will DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(error)); |
| |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| /* |
| * sctp_sf_do_9_2_shut |
| * |
| * Section: 9.2 |
| * Upon the reception of the SHUTDOWN, the peer endpoint shall |
| * - enter the SHUTDOWN-RECEIVED state, |
| * |
| * - stop accepting new data from its SCTP user |
| * |
| * - verify, by checking the Cumulative TSN Ack field of the chunk, |
| * that all its outstanding DATA chunks have been received by the |
| * SHUTDOWN sender. |
| * |
| * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT |
| * send a SHUTDOWN in response to a ULP request. And should discard |
| * subsequent SHUTDOWN chunks. |
| * |
| * If there are still outstanding DATA chunks left, the SHUTDOWN |
| * receiver shall continue to follow normal data transmission |
| * procedures defined in Section 6 until all outstanding DATA chunks |
| * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept |
| * new data from its SCTP user. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| enum sctp_disposition disposition; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_shutdownhdr *sdh; |
| struct sctp_ulpevent *ev; |
| __u32 ctsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the SHUTDOWN chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Convert the elaborate header. */ |
| sdh = (struct sctp_shutdownhdr *)chunk->skb->data; |
| skb_pull(chunk->skb, sizeof(*sdh)); |
| chunk->subh.shutdown_hdr = sdh; |
| ctsn = ntohl(sdh->cum_tsn_ack); |
| |
| if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
| pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
| asoc->ctsn_ack_point); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* If Cumulative TSN Ack beyond the max tsn currently |
| * send, terminating the association and respond to the |
| * sender with an ABORT. |
| */ |
| if (!TSN_lt(ctsn, asoc->next_tsn)) |
| return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
| |
| /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT |
| * When a peer sends a SHUTDOWN, SCTP delivers this notification to |
| * inform the application that it should cease sending data. |
| */ |
| ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); |
| if (!ev) { |
| disposition = SCTP_DISPOSITION_NOMEM; |
| goto out; |
| } |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| |
| /* Upon the reception of the SHUTDOWN, the peer endpoint shall |
| * - enter the SHUTDOWN-RECEIVED state, |
| * - stop accepting new data from its SCTP user |
| * |
| * [This is implicit in the new state.] |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); |
| disposition = SCTP_DISPOSITION_CONSUME; |
| |
| if (sctp_outq_is_empty(&asoc->outqueue)) { |
| disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type, |
| arg, commands); |
| } |
| |
| if (SCTP_DISPOSITION_NOMEM == disposition) |
| goto out; |
| |
| /* - verify, by checking the Cumulative TSN Ack field of the |
| * chunk, that all its outstanding DATA chunks have been |
| * received by the SHUTDOWN sender. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
| SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack)); |
| |
| out: |
| return disposition; |
| } |
| |
| /* |
| * sctp_sf_do_9_2_shut_ctsn |
| * |
| * Once an endpoint has reached the SHUTDOWN-RECEIVED state, |
| * it MUST NOT send a SHUTDOWN in response to a ULP request. |
| * The Cumulative TSN Ack of the received SHUTDOWN chunk |
| * MUST be processed. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_shut_ctsn( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_shutdownhdr *sdh; |
| __u32 ctsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the SHUTDOWN chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| sdh = (struct sctp_shutdownhdr *)chunk->skb->data; |
| ctsn = ntohl(sdh->cum_tsn_ack); |
| |
| if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
| pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
| asoc->ctsn_ack_point); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* If Cumulative TSN Ack beyond the max tsn currently |
| * send, terminating the association and respond to the |
| * sender with an ABORT. |
| */ |
| if (!TSN_lt(ctsn, asoc->next_tsn)) |
| return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
| |
| /* verify, by checking the Cumulative TSN Ack field of the |
| * chunk, that all its outstanding DATA chunks have been |
| * received by the SHUTDOWN sender. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
| SCTP_BE32(sdh->cum_tsn_ack)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* RFC 2960 9.2 |
| * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk |
| * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination |
| * transport addresses (either in the IP addresses or in the INIT chunk) |
| * that belong to this association, it should discard the INIT chunk and |
| * retransmit the SHUTDOWN ACK chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_reshutack( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *reply; |
| |
| /* Make sure that the chunk has a valid length */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Since we are not going to really process this INIT, there |
| * is no point in verifying chunk boundaries. Just generate |
| * the SHUTDOWN ACK. |
| */ |
| reply = sctp_make_shutdown_ack(asoc, chunk); |
| if (NULL == reply) |
| goto nomem; |
| |
| /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
| * the T2-SHUTDOWN timer. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| |
| /* and restart the T2-shutdown timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * sctp_sf_do_ecn_cwr |
| * |
| * Section: Appendix A: Explicit Congestion Notification |
| * |
| * CWR: |
| * |
| * RFC 2481 details a specific bit for a sender to send in the header of |
| * its next outbound TCP segment to indicate to its peer that it has |
| * reduced its congestion window. This is termed the CWR bit. For |
| * SCTP the same indication is made by including the CWR chunk. |
| * This chunk contains one data element, i.e. the TSN number that |
| * was sent in the ECNE chunk. This element represents the lowest |
| * TSN number in the datagram that was originally marked with the |
| * CE bit. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_ecn_cwr(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_cwrhdr *cwr; |
| u32 lowest_tsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| cwr = (struct sctp_cwrhdr *)chunk->skb->data; |
| skb_pull(chunk->skb, sizeof(*cwr)); |
| |
| lowest_tsn = ntohl(cwr->lowest_tsn); |
| |
| /* Does this CWR ack the last sent congestion notification? */ |
| if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) { |
| /* Stop sending ECNE. */ |
| sctp_add_cmd_sf(commands, |
| SCTP_CMD_ECN_CWR, |
| SCTP_U32(lowest_tsn)); |
| } |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * sctp_sf_do_ecne |
| * |
| * Section: Appendix A: Explicit Congestion Notification |
| * |
| * ECN-Echo |
| * |
| * RFC 2481 details a specific bit for a receiver to send back in its |
| * TCP acknowledgements to notify the sender of the Congestion |
| * Experienced (CE) bit having arrived from the network. For SCTP this |
| * same indication is made by including the ECNE chunk. This chunk |
| * contains one data element, i.e. the lowest TSN associated with the IP |
| * datagram marked with the CE bit..... |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_ecne(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_ecnehdr *ecne; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| ecne = (struct sctp_ecnehdr *)chunk->skb->data; |
| skb_pull(chunk->skb, sizeof(*ecne)); |
| |
| /* If this is a newer ECNE than the last CWR packet we sent out */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, |
| SCTP_U32(ntohl(ecne->lowest_tsn))); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
| * |
| * The SCTP endpoint MUST always acknowledge the reception of each valid |
| * DATA chunk. |
| * |
| * The guidelines on delayed acknowledgement algorithm specified in |
| * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
| * acknowledgement SHOULD be generated for at least every second packet |
| * (not every second DATA chunk) received, and SHOULD be generated within |
| * 200 ms of the arrival of any unacknowledged DATA chunk. In some |
| * situations it may be beneficial for an SCTP transmitter to be more |
| * conservative than the algorithms detailed in this document allow. |
| * However, an SCTP transmitter MUST NOT be more aggressive than the |
| * following algorithms allow. |
| * |
| * A SCTP receiver MUST NOT generate more than one SACK for every |
| * incoming packet, other than to update the offered window as the |
| * receiving application consumes new data. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| union sctp_arg force = SCTP_NOFORCE(); |
| struct sctp_chunk *chunk = arg; |
| int error; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| error = sctp_eat_data(asoc, chunk, commands); |
| switch (error) { |
| case SCTP_IERROR_NO_ERROR: |
| break; |
| case SCTP_IERROR_HIGH_TSN: |
| case SCTP_IERROR_BAD_STREAM: |
| SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
| goto discard_noforce; |
| case SCTP_IERROR_DUP_TSN: |
| case SCTP_IERROR_IGNORE_TSN: |
| SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
| goto discard_force; |
| case SCTP_IERROR_NO_DATA: |
| return SCTP_DISPOSITION_ABORT; |
| case SCTP_IERROR_PROTO_VIOLATION: |
| return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, |
| (u8 *)chunk->subh.data_hdr, |
| sctp_datahdr_len(&asoc->stream)); |
| default: |
| BUG(); |
| } |
| |
| if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM) |
| force = SCTP_FORCE(); |
| |
| if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| } |
| |
| /* If this is the last chunk in a packet, we need to count it |
| * toward sack generation. Note that we need to SACK every |
| * OTHER packet containing data chunks, EVEN IF WE DISCARD |
| * THEM. We elect to NOT generate SACK's if the chunk fails |
| * the verification tag test. |
| * |
| * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
| * |
| * The SCTP endpoint MUST always acknowledge the reception of |
| * each valid DATA chunk. |
| * |
| * The guidelines on delayed acknowledgement algorithm |
| * specified in Section 4.2 of [RFC2581] SHOULD be followed. |
| * Specifically, an acknowledgement SHOULD be generated for at |
| * least every second packet (not every second DATA chunk) |
| * received, and SHOULD be generated within 200 ms of the |
| * arrival of any unacknowledged DATA chunk. In some |
| * situations it may be beneficial for an SCTP transmitter to |
| * be more conservative than the algorithms detailed in this |
| * document allow. However, an SCTP transmitter MUST NOT be |
| * more aggressive than the following algorithms allow. |
| */ |
| if (chunk->end_of_packet) |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| discard_force: |
| /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
| * |
| * When a packet arrives with duplicate DATA chunk(s) and with |
| * no new DATA chunk(s), the endpoint MUST immediately send a |
| * SACK with no delay. If a packet arrives with duplicate |
| * DATA chunk(s) bundled with new DATA chunks, the endpoint |
| * MAY immediately send a SACK. Normally receipt of duplicate |
| * DATA chunks will occur when the original SACK chunk was lost |
| * and the peer's RTO has expired. The duplicate TSN number(s) |
| * SHOULD be reported in the SACK as duplicate. |
| */ |
| /* In our case, we split the MAY SACK advice up whether or not |
| * the last chunk is a duplicate.' |
| */ |
| if (chunk->end_of_packet) |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| return SCTP_DISPOSITION_DISCARD; |
| |
| discard_noforce: |
| if (chunk->end_of_packet) |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* |
| * sctp_sf_eat_data_fast_4_4 |
| * |
| * Section: 4 (4) |
| * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received |
| * DATA chunks without delay. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_eat_data_fast_4_4( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| int error; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| error = sctp_eat_data(asoc, chunk, commands); |
| switch (error) { |
| case SCTP_IERROR_NO_ERROR: |
| case SCTP_IERROR_HIGH_TSN: |
| case SCTP_IERROR_DUP_TSN: |
| case SCTP_IERROR_IGNORE_TSN: |
| case SCTP_IERROR_BAD_STREAM: |
| break; |
| case SCTP_IERROR_NO_DATA: |
| return SCTP_DISPOSITION_ABORT; |
| case SCTP_IERROR_PROTO_VIOLATION: |
| return sctp_sf_abort_violation(net, ep, asoc, chunk, commands, |
| (u8 *)chunk->subh.data_hdr, |
| sctp_datahdr_len(&asoc->stream)); |
| default: |
| BUG(); |
| } |
| |
| /* Go a head and force a SACK, since we are shutting down. */ |
| |
| /* Implementor's Guide. |
| * |
| * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
| * respond to each received packet containing one or more DATA chunk(s) |
| * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
| */ |
| if (chunk->end_of_packet) { |
| /* We must delay the chunk creation since the cumulative |
| * TSN has not been updated yet. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Section: 6.2 Processing a Received SACK |
| * D) Any time a SACK arrives, the endpoint performs the following: |
| * |
| * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, |
| * then drop the SACK. Since Cumulative TSN Ack is monotonically |
| * increasing, a SACK whose Cumulative TSN Ack is less than the |
| * Cumulative TSN Ack Point indicates an out-of-order SACK. |
| * |
| * ii) Set rwnd equal to the newly received a_rwnd minus the number |
| * of bytes still outstanding after processing the Cumulative TSN Ack |
| * and the Gap Ack Blocks. |
| * |
| * iii) If the SACK is missing a TSN that was previously |
| * acknowledged via a Gap Ack Block (e.g., the data receiver |
| * reneged on the data), then mark the corresponding DATA chunk |
| * as available for retransmit: Mark it as missing for fast |
| * retransmit as described in Section 7.2.4 and if no retransmit |
| * timer is running for the destination address to which the DATA |
| * chunk was originally transmitted, then T3-rtx is started for |
| * that destination address. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_sackhdr *sackh; |
| __u32 ctsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the SACK chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_sack_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Pull the SACK chunk from the data buffer */ |
| sackh = sctp_sm_pull_sack(chunk); |
| /* Was this a bogus SACK? */ |
| if (!sackh) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| chunk->subh.sack_hdr = sackh; |
| ctsn = ntohl(sackh->cum_tsn_ack); |
| |
| /* If Cumulative TSN Ack beyond the max tsn currently |
| * send, terminating the association and respond to the |
| * sender with an ABORT. |
| */ |
| if (TSN_lte(asoc->next_tsn, ctsn)) |
| return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands); |
| |
| trace_sctp_probe(ep, asoc, chunk); |
| |
| /* i) If Cumulative TSN Ack is less than the Cumulative TSN |
| * Ack Point, then drop the SACK. Since Cumulative TSN |
| * Ack is monotonically increasing, a SACK whose |
| * Cumulative TSN Ack is less than the Cumulative TSN Ack |
| * Point indicates an out-of-order SACK. |
| */ |
| if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
| pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn, |
| asoc->ctsn_ack_point); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* Return this SACK for further processing. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk)); |
| |
| /* Note: We do the rest of the work on the PROCESS_SACK |
| * sideeffect. |
| */ |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Generate an ABORT in response to a packet. |
| * |
| * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41 |
| * |
| * 8) The receiver should respond to the sender of the OOTB packet with |
| * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
| * MUST fill in the Verification Tag field of the outbound packet |
| * with the value found in the Verification Tag field of the OOTB |
| * packet and set the T-bit in the Chunk Flags to indicate that the |
| * Verification Tag is reflected. After sending this ABORT, the |
| * receiver of the OOTB packet shall discard the OOTB packet and take |
| * no further action. |
| * |
| * Verification Tag: |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| static enum sctp_disposition sctp_sf_tabort_8_4_8( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_packet *packet = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *abort; |
| |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| if (!packet) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* Make an ABORT. The T bit will be set if the asoc |
| * is NULL. |
| */ |
| abort = sctp_make_abort(asoc, chunk, 0); |
| if (!abort) { |
| sctp_ootb_pkt_free(packet); |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Reflect vtag if T-Bit is set */ |
| if (sctp_test_T_bit(abort)) |
| packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| |
| /* Set the skb to the belonging sock for accounting. */ |
| abort->skb->sk = ep->base.sk; |
| |
| sctp_packet_append_chunk(packet, abort); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(packet)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* Handling of SCTP Packets Containing an INIT Chunk Matching an |
| * Existing Associations when the UDP encap port is incorrect. |
| * |
| * From Section 4 at draft-tuexen-tsvwg-sctp-udp-encaps-cons-03. |
| */ |
| static enum sctp_disposition sctp_sf_new_encap_port( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_packet *packet = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *abort; |
| |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| if (!packet) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| abort = sctp_make_new_encap_port(asoc, chunk); |
| if (!abort) { |
| sctp_ootb_pkt_free(packet); |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| abort->skb->sk = ep->base.sk; |
| |
| sctp_packet_append_chunk(packet, abort); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR |
| * event as ULP notification for each cause included in the chunk. |
| * |
| * API 5.3.1.3 - SCTP_REMOTE_ERROR |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_operr_notify(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_errhdr *err; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the ERROR chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| sctp_walk_errors(err, chunk->chunk_hdr); |
| if ((void *)err != (void *)chunk->chunk_end) |
| return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
| (void *)err, commands); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, |
| SCTP_CHUNK(chunk)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Process an inbound SHUTDOWN ACK. |
| * |
| * From Section 9.2: |
| * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
| * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its |
| * peer, and remove all record of the association. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_final(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *reply; |
| struct sctp_ulpevent *ev; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| /* 10.2 H) SHUTDOWN COMPLETE notification |
| * |
| * When SCTP completes the shutdown procedures (section 9.2) this |
| * notification is passed to the upper layer. |
| */ |
| ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
| 0, 0, 0, NULL, GFP_ATOMIC); |
| if (!ev) |
| goto nomem; |
| |
| /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ |
| reply = sctp_make_shutdown_complete(asoc, chunk); |
| if (!reply) |
| goto nomem_chunk; |
| |
| /* Do all the commands now (after allocation), so that we |
| * have consistent state if memory allocation fails |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| |
| /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
| * stop the T2-shutdown timer, |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_CLOSED)); |
| SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| |
| /* ...and remove all record of the association. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| |
| nomem_chunk: |
| sctp_ulpevent_free(ev); |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41. |
| * |
| * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
| * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
| * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
| * packet must fill in the Verification Tag field of the outbound |
| * packet with the Verification Tag received in the SHUTDOWN ACK and |
| * set the T-bit in the Chunk Flags to indicate that the Verification |
| * Tag is reflected. |
| * |
| * 8) The receiver should respond to the sender of the OOTB packet with |
| * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
| * MUST fill in the Verification Tag field of the outbound packet |
| * with the value found in the Verification Tag field of the OOTB |
| * packet and set the T-bit in the Chunk Flags to indicate that the |
| * Verification Tag is reflected. After sending this ABORT, the |
| * receiver of the OOTB packet shall discard the OOTB packet and take |
| * no further action. |
| */ |
| enum sctp_disposition sctp_sf_ootb(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sk_buff *skb = chunk->skb; |
| struct sctp_chunkhdr *ch; |
| struct sctp_errhdr *err; |
| int ootb_cookie_ack = 0; |
| int ootb_shut_ack = 0; |
| __u8 *ch_end; |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
| |
| ch = (struct sctp_chunkhdr *)chunk->chunk_hdr; |
| do { |
| /* Report violation if the chunk is less then minimal */ |
| if (ntohs(ch->length) < sizeof(*ch)) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Report violation if chunk len overflows */ |
| ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length)); |
| if (ch_end > skb_tail_pointer(skb)) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Now that we know we at least have a chunk header, |
| * do things that are type appropriate. |
| */ |
| if (SCTP_CID_SHUTDOWN_ACK == ch->type) |
| ootb_shut_ack = 1; |
| |
| /* RFC 2960, Section 3.3.7 |
| * Moreover, under any circumstances, an endpoint that |
| * receives an ABORT MUST NOT respond to that ABORT by |
| * sending an ABORT of its own. |
| */ |
| if (SCTP_CID_ABORT == ch->type) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR |
| * or a COOKIE ACK the SCTP Packet should be silently |
| * discarded. |
| */ |
| |
| if (SCTP_CID_COOKIE_ACK == ch->type) |
| ootb_cookie_ack = 1; |
| |
| if (SCTP_CID_ERROR == ch->type) { |
| sctp_walk_errors(err, ch) { |
| if (SCTP_ERROR_STALE_COOKIE == err->cause) { |
| ootb_cookie_ack = 1; |
| break; |
| } |
| } |
| } |
| |
| ch = (struct sctp_chunkhdr *)ch_end; |
| } while (ch_end < skb_tail_pointer(skb)); |
| |
| if (ootb_shut_ack) |
| return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands); |
| else if (ootb_cookie_ack) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| else |
| return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Handle an "Out of the blue" SHUTDOWN ACK. |
| * |
| * Section: 8.4 5, sctpimpguide 2.41. |
| * |
| * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
| * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
| * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
| * packet must fill in the Verification Tag field of the outbound |
| * packet with the Verification Tag received in the SHUTDOWN ACK and |
| * set the T-bit in the Chunk Flags to indicate that the Verification |
| * Tag is reflected. |
| * |
| * Inputs |
| * (endpoint, asoc, type, arg, commands) |
| * |
| * Outputs |
| * (enum sctp_disposition) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| static enum sctp_disposition sctp_sf_shut_8_4_5( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_packet *packet = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *shut; |
| |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| if (!packet) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* Make an SHUTDOWN_COMPLETE. |
| * The T bit will be set if the asoc is NULL. |
| */ |
| shut = sctp_make_shutdown_complete(asoc, chunk); |
| if (!shut) { |
| sctp_ootb_pkt_free(packet); |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Reflect vtag if T-Bit is set */ |
| if (sctp_test_T_bit(shut)) |
| packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| |
| /* Set the skb to the belonging sock for accounting. */ |
| shut->skb->sk = ep->base.sk; |
| |
| sctp_packet_append_chunk(packet, shut); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| /* If the chunk length is invalid, we don't want to process |
| * the reset of the packet. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* We need to discard the rest of the packet to prevent |
| * potential boomming attacks from additional bundled chunks. |
| * This is documented in SCTP Threats ID. |
| */ |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. |
| * |
| * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK |
| * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the |
| * procedures in section 8.4 SHOULD be followed, in other words it |
| * should be treated as an Out Of The Blue packet. |
| * [This means that we do NOT check the Verification Tag on these |
| * chunks. --piggy ] |
| * |
| */ |
| enum sctp_disposition sctp_sf_do_8_5_1_E_sa(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Although we do have an association in this case, it corresponds |
| * to a restarted association. So the packet is treated as an OOTB |
| * packet and the state function that handles OOTB SHUTDOWN_ACK is |
| * called with a NULL association. |
| */ |
| SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES); |
| |
| return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands); |
| } |
| |
| /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ |
| enum sctp_disposition sctp_sf_do_asconf(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_paramhdr *err_param = NULL; |
| struct sctp_chunk *asconf_ack = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_addiphdr *hdr; |
| __u32 serial; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* ADD-IP: Section 4.1.1 |
| * This chunk MUST be sent in an authenticated way by using |
| * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
| * is received unauthenticated it MUST be silently discarded as |
| * described in [I-D.ietf-tsvwg-sctp-auth]. |
| */ |
| if (!asoc->peer.asconf_capable || |
| (!net->sctp.addip_noauth && !chunk->auth)) |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Make sure that the ASCONF ADDIP chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| hdr = (struct sctp_addiphdr *)chunk->skb->data; |
| serial = ntohl(hdr->serial); |
| |
| /* Verify the ASCONF chunk before processing it. */ |
| if (!sctp_verify_asconf(asoc, chunk, true, &err_param)) |
| return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
| (void *)err_param, commands); |
| |
| /* ADDIP 5.2 E1) Compare the value of the serial number to the value |
| * the endpoint stored in a new association variable |
| * 'Peer-Serial-Number'. |
| */ |
| if (serial == asoc->peer.addip_serial + 1) { |
| /* If this is the first instance of ASCONF in the packet, |
| * we can clean our old ASCONF-ACKs. |
| */ |
| if (!chunk->has_asconf) |
| sctp_assoc_clean_asconf_ack_cache(asoc); |
| |
| /* ADDIP 5.2 E4) When the Sequence Number matches the next one |
| * expected, process the ASCONF as described below and after |
| * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to |
| * the response packet and cache a copy of it (in the event it |
| * later needs to be retransmitted). |
| * |
| * Essentially, do V1-V5. |
| */ |
| asconf_ack = sctp_process_asconf((struct sctp_association *) |
| asoc, chunk); |
| if (!asconf_ack) |
| return SCTP_DISPOSITION_NOMEM; |
| } else if (serial < asoc->peer.addip_serial + 1) { |
| /* ADDIP 5.2 E2) |
| * If the value found in the Sequence Number is less than the |
| * ('Peer- Sequence-Number' + 1), simply skip to the next |
| * ASCONF, and include in the outbound response packet |
| * any previously cached ASCONF-ACK response that was |
| * sent and saved that matches the Sequence Number of the |
| * ASCONF. Note: It is possible that no cached ASCONF-ACK |
| * Chunk exists. This will occur when an older ASCONF |
| * arrives out of order. In such a case, the receiver |
| * should skip the ASCONF Chunk and not include ASCONF-ACK |
| * Chunk for that chunk. |
| */ |
| asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial); |
| if (!asconf_ack) |
| return SCTP_DISPOSITION_DISCARD; |
| |
| /* Reset the transport so that we select the correct one |
| * this time around. This is to make sure that we don't |
| * accidentally use a stale transport that's been removed. |
| */ |
| asconf_ack->transport = NULL; |
| } else { |
| /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since |
| * it must be either a stale packet or from an attacker. |
| */ |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* ADDIP 5.2 E6) The destination address of the SCTP packet |
| * containing the ASCONF-ACK Chunks MUST be the source address of |
| * the SCTP packet that held the ASCONF Chunks. |
| * |
| * To do this properly, we'll set the destination address of the chunk |
| * and at the transmit time, will try look up the transport to use. |
| * Since ASCONFs may be bundled, the correct transport may not be |
| * created until we process the entire packet, thus this workaround. |
| */ |
| asconf_ack->dest = chunk->source; |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); |
| if (asoc->new_transport) { |
| sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands); |
| ((struct sctp_association *)asoc)->new_transport = NULL; |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| static enum sctp_disposition sctp_send_next_asconf( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| struct sctp_association *asoc, |
| const union sctp_subtype type, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *asconf; |
| struct list_head *entry; |
| |
| if (list_empty(&asoc->addip_chunk_list)) |
| return SCTP_DISPOSITION_CONSUME; |
| |
| entry = asoc->addip_chunk_list.next; |
| asconf = list_entry(entry, struct sctp_chunk, list); |
| |
| list_del_init(entry); |
| sctp_chunk_hold(asconf); |
| asoc->addip_last_asconf = asconf; |
| |
| return sctp_sf_do_prm_asconf(net, ep, asoc, type, asconf, commands); |
| } |
| |
| /* |
| * ADDIP Section 4.3 General rules for address manipulation |
| * When building TLV parameters for the ASCONF Chunk that will add or |
| * delete IP addresses the D0 to D13 rules should be applied: |
| */ |
| enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *last_asconf = asoc->addip_last_asconf; |
| struct sctp_paramhdr *err_param = NULL; |
| struct sctp_chunk *asconf_ack = arg; |
| struct sctp_addiphdr *addip_hdr; |
| __u32 sent_serial, rcvd_serial; |
| struct sctp_chunk *abort; |
| |
| if (!sctp_vtag_verify(asconf_ack, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* ADD-IP, Section 4.1.2: |
| * This chunk MUST be sent in an authenticated way by using |
| * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
| * is received unauthenticated it MUST be silently discarded as |
| * described in [I-D.ietf-tsvwg-sctp-auth]. |
| */ |
| if (!asoc->peer.asconf_capable || |
| (!net->sctp.addip_noauth && !asconf_ack->auth)) |
| return sctp_sf_discard_chunk(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Make sure that the ADDIP chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(asconf_ack, |
| sizeof(struct sctp_addip_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| addip_hdr = (struct sctp_addiphdr *)asconf_ack->skb->data; |
| rcvd_serial = ntohl(addip_hdr->serial); |
| |
| /* Verify the ASCONF-ACK chunk before processing it. */ |
| if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param)) |
| return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
| (void *)err_param, commands); |
| |
| if (last_asconf) { |
| addip_hdr = (struct sctp_addiphdr *)last_asconf->subh.addip_hdr; |
| sent_serial = ntohl(addip_hdr->serial); |
| } else { |
| sent_serial = asoc->addip_serial - 1; |
| } |
| |
| /* D0) If an endpoint receives an ASCONF-ACK that is greater than or |
| * equal to the next serial number to be used but no ASCONF chunk is |
| * outstanding the endpoint MUST ABORT the association. Note that a |
| * sequence number is greater than if it is no more than 2^^31-1 |
| * larger than the current sequence number (using serial arithmetic). |
| */ |
| if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && |
| !(asoc->addip_last_asconf)) { |
| abort = sctp_make_abort(asoc, asconf_ack, |
| sizeof(struct sctp_errhdr)); |
| if (abort) { |
| sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(abort)); |
| } |
| /* We are going to ABORT, so we might as well stop |
| * processing the rest of the chunks in the packet. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| |
| if (!sctp_process_asconf_ack((struct sctp_association *)asoc, |
| asconf_ack)) |
| return sctp_send_next_asconf(net, ep, |
| (struct sctp_association *)asoc, |
| type, commands); |
| |
| abort = sctp_make_abort(asoc, asconf_ack, |
| sizeof(struct sctp_errhdr)); |
| if (abort) { |
| sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(abort)); |
| } |
| /* We are going to ABORT, so we might as well stop |
| * processing the rest of the chunks in the packet. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */ |
| enum sctp_disposition sctp_sf_do_reconf(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_paramhdr *err_param = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_reconf_chunk *hdr; |
| union sctp_params param; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* Make sure that the RECONF chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(*hdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| if (!sctp_verify_reconf(asoc, chunk, &err_param)) |
| return sctp_sf_violation_paramlen(net, ep, asoc, type, arg, |
| (void *)err_param, commands); |
| |
| hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; |
| sctp_walk_params(param, hdr, params) { |
| struct sctp_chunk *reply = NULL; |
| struct sctp_ulpevent *ev = NULL; |
| |
| if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST) |
| reply = sctp_process_strreset_outreq( |
| (struct sctp_association *)asoc, param, &ev); |
| else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST) |
| reply = sctp_process_strreset_inreq( |
| (struct sctp_association *)asoc, param, &ev); |
| else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST) |
| reply = sctp_process_strreset_tsnreq( |
| (struct sctp_association *)asoc, param, &ev); |
| else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) |
| reply = sctp_process_strreset_addstrm_out( |
| (struct sctp_association *)asoc, param, &ev); |
| else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) |
| reply = sctp_process_strreset_addstrm_in( |
| (struct sctp_association *)asoc, param, &ev); |
| else if (param.p->type == SCTP_PARAM_RESET_RESPONSE) |
| reply = sctp_process_strreset_resp( |
| (struct sctp_association *)asoc, param, &ev); |
| |
| if (ev) |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| |
| if (reply) |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(reply)); |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP |
| * |
| * When a FORWARD TSN chunk arrives, the data receiver MUST first update |
| * its cumulative TSN point to the value carried in the FORWARD TSN |
| * chunk, and then MUST further advance its cumulative TSN point locally |
| * if possible. |
| * After the above processing, the data receiver MUST stop reporting any |
| * missing TSNs earlier than or equal to the new cumulative TSN point. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
| struct sctp_chunk *chunk = arg; |
| __u16 len; |
| __u32 tsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| if (!asoc->peer.prsctp_capable) |
| return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the FORWARD_TSN chunk has valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
| chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
| len = ntohs(chunk->chunk_hdr->length); |
| len -= sizeof(struct sctp_chunkhdr); |
| skb_pull(chunk->skb, len); |
| |
| tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
| pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
| |
| /* The TSN is too high--silently discard the chunk and count on it |
| * getting retransmitted later. |
| */ |
| if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
| goto discard_noforce; |
| |
| if (!asoc->stream.si->validate_ftsn(chunk)) |
| goto discard_noforce; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
| if (len > sctp_ftsnhdr_len(&asoc->stream)) |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
| SCTP_CHUNK(chunk)); |
| |
| /* Count this as receiving DATA. */ |
| if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| } |
| |
| /* FIXME: For now send a SACK, but DATA processing may |
| * send another. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| discard_noforce: |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| enum sctp_disposition sctp_sf_eat_fwd_tsn_fast( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
| struct sctp_chunk *chunk = arg; |
| __u16 len; |
| __u32 tsn; |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| if (!asoc->peer.prsctp_capable) |
| return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the FORWARD_TSN chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
| chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
| len = ntohs(chunk->chunk_hdr->length); |
| len -= sizeof(struct sctp_chunkhdr); |
| skb_pull(chunk->skb, len); |
| |
| tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
| pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
| |
| /* The TSN is too high--silently discard the chunk and count on it |
| * getting retransmitted later. |
| */ |
| if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
| goto gen_shutdown; |
| |
| if (!asoc->stream.si->validate_ftsn(chunk)) |
| goto gen_shutdown; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
| if (len > sctp_ftsnhdr_len(&asoc->stream)) |
| sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
| SCTP_CHUNK(chunk)); |
| |
| /* Go a head and force a SACK, since we are shutting down. */ |
| gen_shutdown: |
| /* Implementor's Guide. |
| * |
| * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
| * respond to each received packet containing one or more DATA chunk(s) |
| * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * SCTP-AUTH Section 6.3 Receiving authenticated chunks |
| * |
| * The receiver MUST use the HMAC algorithm indicated in the HMAC |
| * Identifier field. If this algorithm was not specified by the |
| * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk |
| * during association setup, the AUTH chunk and all chunks after it MUST |
| * be discarded and an ERROR chunk SHOULD be sent with the error cause |
| * defined in Section 4.1. |
| * |
| * If an endpoint with no shared key receives a Shared Key Identifier |
| * other than 0, it MUST silently discard all authenticated chunks. If |
| * the endpoint has at least one endpoint pair shared key for the peer, |
| * it MUST use the key specified by the Shared Key Identifier if a |
| * key has been configured for that Shared Key Identifier. If no |
| * endpoint pair shared key has been configured for that Shared Key |
| * Identifier, all authenticated chunks MUST be silently discarded. |
| * |
| * Verification Tag: 8.5 Verification Tag [Normal verification] |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| static enum sctp_ierror sctp_sf_authenticate( |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk) |
| { |
| struct sctp_shared_key *sh_key = NULL; |
| struct sctp_authhdr *auth_hdr; |
| __u8 *save_digest, *digest; |
| struct sctp_hmac *hmac; |
| unsigned int sig_len; |
| __u16 key_id; |
| |
| /* Pull in the auth header, so we can do some more verification */ |
| auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
| chunk->subh.auth_hdr = auth_hdr; |
| skb_pull(chunk->skb, sizeof(*auth_hdr)); |
| |
| /* Make sure that we support the HMAC algorithm from the auth |
| * chunk. |
| */ |
| if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id)) |
| return SCTP_IERROR_AUTH_BAD_HMAC; |
| |
| /* Make sure that the provided shared key identifier has been |
| * configured |
| */ |
| key_id = ntohs(auth_hdr->shkey_id); |
| if (key_id != asoc->active_key_id) { |
| sh_key = sctp_auth_get_shkey(asoc, key_id); |
| if (!sh_key) |
| return SCTP_IERROR_AUTH_BAD_KEYID; |
| } |
| |
| /* Make sure that the length of the signature matches what |
| * we expect. |
| */ |
| sig_len = ntohs(chunk->chunk_hdr->length) - |
| sizeof(struct sctp_auth_chunk); |
| hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id)); |
| if (sig_len != hmac->hmac_len) |
| return SCTP_IERROR_PROTO_VIOLATION; |
| |
| /* Now that we've done validation checks, we can compute and |
| * verify the hmac. The steps involved are: |
| * 1. Save the digest from the chunk. |
| * 2. Zero out the digest in the chunk. |
| * 3. Compute the new digest |
| * 4. Compare saved and new digests. |
| */ |
| digest = auth_hdr->hmac; |
| skb_pull(chunk->skb, sig_len); |
| |
| save_digest = kmemdup(digest, sig_len, GFP_ATOMIC); |
| if (!save_digest) |
| goto nomem; |
| |
| memset(digest, 0, sig_len); |
| |
| sctp_auth_calculate_hmac(asoc, chunk->skb, |
| (struct sctp_auth_chunk *)chunk->chunk_hdr, |
| sh_key, GFP_ATOMIC); |
| |
| /* Discard the packet if the digests do not match */ |
| if (memcmp(save_digest, digest, sig_len)) { |
| kfree(save_digest); |
| return SCTP_IERROR_BAD_SIG; |
| } |
| |
| kfree(save_digest); |
| chunk->auth = 1; |
| |
| return SCTP_IERROR_NO_ERROR; |
| nomem: |
| return SCTP_IERROR_NOMEM; |
| } |
| |
| enum sctp_disposition sctp_sf_eat_auth(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_authhdr *auth_hdr; |
| struct sctp_chunk *err_chunk; |
| enum sctp_ierror error; |
| |
| /* Make sure that the peer has AUTH capable */ |
| if (!asoc->peer.auth_capable) |
| return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands); |
| |
| if (!sctp_vtag_verify(chunk, asoc)) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| SCTP_NULL()); |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* Make sure that the AUTH chunk has valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
| error = sctp_sf_authenticate(asoc, chunk); |
| switch (error) { |
| case SCTP_IERROR_AUTH_BAD_HMAC: |
| /* Generate the ERROR chunk and discard the rest |
| * of the packet |
| */ |
| err_chunk = sctp_make_op_error(asoc, chunk, |
| SCTP_ERROR_UNSUP_HMAC, |
| &auth_hdr->hmac_id, |
| sizeof(__u16), 0); |
| if (err_chunk) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err_chunk)); |
| } |
| fallthrough; |
| case SCTP_IERROR_AUTH_BAD_KEYID: |
| case SCTP_IERROR_BAD_SIG: |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| case SCTP_IERROR_PROTO_VIOLATION: |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| case SCTP_IERROR_NOMEM: |
| return SCTP_DISPOSITION_NOMEM; |
| |
| default: /* Prevent gcc warnings */ |
| break; |
| } |
| |
| if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) { |
| struct sctp_ulpevent *ev; |
| |
| ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id), |
| SCTP_AUTH_NEW_KEY, GFP_ATOMIC); |
| |
| if (!ev) |
| return -ENOMEM; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| SCTP_ULPEVENT(ev)); |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Process an unknown chunk. |
| * |
| * Section: 3.2. Also, 2.1 in the implementor's guide. |
| * |
| * Chunk Types are encoded such that the highest-order two bits specify |
| * the action that must be taken if the processing endpoint does not |
| * recognize the Chunk Type. |
| * |
| * 00 - Stop processing this SCTP packet and discard it, do not process |
| * any further chunks within it. |
| * |
| * 01 - Stop processing this SCTP packet and discard it, do not process |
| * any further chunks within it, and report the unrecognized |
| * chunk in an 'Unrecognized Chunk Type'. |
| * |
| * 10 - Skip this chunk and continue processing. |
| * |
| * 11 - Skip this chunk and continue processing, but report in an ERROR |
| * Chunk using the 'Unrecognized Chunk Type' cause of error. |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_unk_chunk(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *unk_chunk = arg; |
| struct sctp_chunk *err_chunk; |
| struct sctp_chunkhdr *hdr; |
| |
| pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk); |
| |
| if (!sctp_vtag_verify(unk_chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| |
| /* Make sure that the chunk has a valid length. |
| * Since we don't know the chunk type, we use a general |
| * chunkhdr structure to make a comparison. |
| */ |
| if (!sctp_chunk_length_valid(unk_chunk, sizeof(*hdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| switch (type.chunk & SCTP_CID_ACTION_MASK) { |
| case SCTP_CID_ACTION_DISCARD: |
| /* Discard the packet. */ |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| case SCTP_CID_ACTION_DISCARD_ERR: |
| /* Generate an ERROR chunk as response. */ |
| hdr = unk_chunk->chunk_hdr; |
| err_chunk = sctp_make_op_error(asoc, unk_chunk, |
| SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
| SCTP_PAD4(ntohs(hdr->length)), |
| 0); |
| if (err_chunk) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err_chunk)); |
| } |
| |
| /* Discard the packet. */ |
| sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); |
| return SCTP_DISPOSITION_CONSUME; |
| case SCTP_CID_ACTION_SKIP: |
| /* Skip the chunk. */ |
| return SCTP_DISPOSITION_DISCARD; |
| case SCTP_CID_ACTION_SKIP_ERR: |
| /* Generate an ERROR chunk as response. */ |
| hdr = unk_chunk->chunk_hdr; |
| err_chunk = sctp_make_op_error(asoc, unk_chunk, |
| SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
| SCTP_PAD4(ntohs(hdr->length)), |
| 0); |
| if (err_chunk) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err_chunk)); |
| } |
| /* Skip the chunk. */ |
| return SCTP_DISPOSITION_CONSUME; |
| default: |
| break; |
| } |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* |
| * Discard the chunk. |
| * |
| * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 |
| * [Too numerous to mention...] |
| * Verification Tag: No verification needed. |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_discard_chunk(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| /* Make sure that the chunk has a valid length. |
| * Since we don't know the chunk type, we use a general |
| * chunkhdr structure to make a comparison. |
| */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /* |
| * Discard the whole packet. |
| * |
| * Section: 8.4 2) |
| * |
| * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST |
| * silently discard the OOTB packet and take no further action. |
| * |
| * Verification Tag: No verification necessary |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_pdiscard(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS); |
| sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| |
| /* |
| * The other end is violating protocol. |
| * |
| * Section: Not specified |
| * Verification Tag: Not specified |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (asoc, reply_msg, msg_up, timers, counters) |
| * |
| * We simply tag the chunk as a violation. The state machine will log |
| * the violation and continue. |
| */ |
| enum sctp_disposition sctp_sf_violation(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| /* Make sure that the chunk has a valid length. */ |
| if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, |
| commands); |
| |
| return SCTP_DISPOSITION_VIOLATION; |
| } |
| |
| /* |
| * Common function to handle a protocol violation. |
| */ |
| static enum sctp_disposition sctp_sf_abort_violation( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| void *arg, |
| struct sctp_cmd_seq *commands, |
| const __u8 *payload, |
| const size_t paylen) |
| { |
| struct sctp_packet *packet = NULL; |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *abort = NULL; |
| |
| /* SCTP-AUTH, Section 6.3: |
| * It should be noted that if the receiver wants to tear |
| * down an association in an authenticated way only, the |
| * handling of malformed packets should not result in |
| * tearing down the association. |
| * |
| * This means that if we only want to abort associations |
| * in an authenticated way (i.e AUTH+ABORT), then we |
| * can't destroy this association just because the packet |
| * was malformed. |
| */ |
| if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
| goto discard; |
| |
| /* Make the abort chunk. */ |
| abort = sctp_make_abort_violation(asoc, chunk, payload, paylen); |
| if (!abort) |
| goto nomem; |
| |
| if (asoc) { |
| /* Treat INIT-ACK as a special case during COOKIE-WAIT. */ |
| if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK && |
| !asoc->peer.i.init_tag) { |
| struct sctp_initack_chunk *initack; |
| |
| initack = (struct sctp_initack_chunk *)chunk->chunk_hdr; |
| if (!sctp_chunk_length_valid(chunk, sizeof(*initack))) |
| abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T; |
| else { |
| unsigned int inittag; |
| |
| inittag = ntohl(initack->init_hdr.init_tag); |
| sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG, |
| SCTP_U32(inittag)); |
| } |
| } |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNREFUSED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
| } else { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| } |
| } else { |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| |
| if (!packet) |
| goto nomem_pkt; |
| |
| if (sctp_test_T_bit(abort)) |
| packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| |
| abort->skb->sk = ep->base.sk; |
| |
| sctp_packet_append_chunk(packet, abort); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| } |
| |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| |
| discard: |
| sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); |
| return SCTP_DISPOSITION_ABORT; |
| |
| nomem_pkt: |
| sctp_chunk_free(abort); |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Handle a protocol violation when the chunk length is invalid. |
| * "Invalid" length is identified as smaller than the minimal length a |
| * given chunk can be. For example, a SACK chunk has invalid length |
| * if its length is set to be smaller than the size of struct sctp_sack_chunk. |
| * |
| * We inform the other end by sending an ABORT with a Protocol Violation |
| * error code. |
| * |
| * Section: Not specified |
| * Verification Tag: Nothing to do |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * Outputs |
| * (reply_msg, msg_up, counters) |
| * |
| * Generate an ABORT chunk and terminate the association. |
| */ |
| static enum sctp_disposition sctp_sf_violation_chunklen( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| static const char err_str[] = "The following chunk had invalid length:"; |
| |
| return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
| sizeof(err_str)); |
| } |
| |
| /* |
| * Handle a protocol violation when the parameter length is invalid. |
| * If the length is smaller than the minimum length of a given parameter, |
| * or accumulated length in multi parameters exceeds the end of the chunk, |
| * the length is considered as invalid. |
| */ |
| static enum sctp_disposition sctp_sf_violation_paramlen( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, void *ext, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_paramhdr *param = ext; |
| struct sctp_chunk *abort = NULL; |
| struct sctp_chunk *chunk = arg; |
| |
| if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
| goto discard; |
| |
| /* Make the abort chunk. */ |
| abort = sctp_make_violation_paramlen(asoc, chunk, param); |
| if (!abort) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| |
| discard: |
| sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands); |
| return SCTP_DISPOSITION_ABORT; |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Handle a protocol violation when the peer trying to advance the |
| * cumulative tsn ack to a point beyond the max tsn currently sent. |
| * |
| * We inform the other end by sending an ABORT with a Protocol Violation |
| * error code. |
| */ |
| static enum sctp_disposition sctp_sf_violation_ctsn( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:"; |
| |
| return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
| sizeof(err_str)); |
| } |
| |
| /* Handle protocol violation of an invalid chunk bundling. For example, |
| * when we have an association and we receive bundled INIT-ACK, or |
| * SHUTDOWN-COMPLETE, our peer is clearly violating the "MUST NOT bundle" |
| * statement from the specs. Additionally, there might be an attacker |
| * on the path and we may not want to continue this communication. |
| */ |
| static enum sctp_disposition sctp_sf_violation_chunk( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| static const char err_str[] = "The following chunk violates protocol:"; |
| |
| if (!asoc) |
| return sctp_sf_violation(net, ep, asoc, type, arg, commands); |
| |
| return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str, |
| sizeof(err_str)); |
| } |
| /*************************************************************************** |
| * These are the state functions for handling primitive (Section 10) events. |
| ***************************************************************************/ |
| /* |
| * sctp_sf_do_prm_asoc |
| * |
| * Section: 10.1 ULP-to-SCTP |
| * B) Associate |
| * |
| * Format: ASSOCIATE(local SCTP instance name, destination transport addr, |
| * outbound stream count) |
| * -> association id [,destination transport addr list] [,outbound stream |
| * count] |
| * |
| * This primitive allows the upper layer to initiate an association to a |
| * specific peer endpoint. |
| * |
| * The peer endpoint shall be specified by one of the transport addresses |
| * which defines the endpoint (see Section 1.4). If the local SCTP |
| * instance has not been initialized, the ASSOCIATE is considered an |
| * error. |
| * [This is not relevant for the kernel implementation since we do all |
| * initialization at boot time. It we hadn't initialized we wouldn't |
| * get anywhere near this code.] |
| * |
| * An association id, which is a local handle to the SCTP association, |
| * will be returned on successful establishment of the association. If |
| * SCTP is not able to open an SCTP association with the peer endpoint, |
| * an error is returned. |
| * [In the kernel implementation, the struct sctp_association needs to |
| * be created BEFORE causing this primitive to run.] |
| * |
| * Other association parameters may be returned, including the |
| * complete destination transport addresses of the peer as well as the |
| * outbound stream count of the local endpoint. One of the transport |
| * address from the returned destination addresses will be selected by |
| * the local endpoint as default primary path for sending SCTP packets |
| * to this peer. The returned "destination transport addr list" can |
| * be used by the ULP to change the default primary path or to force |
| * sending a packet to a specific transport address. [All of this |
| * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING |
| * function.] |
| * |
| * Mandatory attributes: |
| * |
| * o local SCTP instance name - obtained from the INITIALIZE operation. |
| * [This is the argument asoc.] |
| * o destination transport addr - specified as one of the transport |
| * addresses of the peer endpoint with which the association is to be |
| * established. |
| * [This is asoc->peer.active_path.] |
| * o outbound stream count - the number of outbound streams the ULP |
| * would like to open towards this peer endpoint. |
| * [BUG: This is not currently implemented.] |
| * Optional attributes: |
| * |
| * None. |
| * |
| * The return value is a disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_prm_asoc(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_association *my_asoc; |
| struct sctp_chunk *repl; |
| |
| /* The comment below says that we enter COOKIE-WAIT AFTER |
| * sending the INIT, but that doesn't actually work in our |
| * implementation... |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
| |
| /* RFC 2960 5.1 Normal Establishment of an Association |
| * |
| * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" |
| * must provide its Verification Tag (Tag_A) in the Initiate |
| * Tag field. Tag_A SHOULD be a random number in the range of |
| * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... |
| */ |
| |
| repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); |
| if (!repl) |
| goto nomem; |
| |
| /* Choose transport for INIT. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
| SCTP_CHUNK(repl)); |
| |
| /* Cast away the const modifier, as we want to just |
| * rerun it through as a sideffect. |
| */ |
| my_asoc = (struct sctp_association *)asoc; |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc)); |
| |
| /* After sending the INIT, "A" starts the T1-init timer and |
| * enters the COOKIE-WAIT state. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Process the SEND primitive. |
| * |
| * Section: 10.1 ULP-to-SCTP |
| * E) Send |
| * |
| * Format: SEND(association id, buffer address, byte count [,context] |
| * [,stream id] [,life time] [,destination transport address] |
| * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) |
| * -> result |
| * |
| * This is the main method to send user data via SCTP. |
| * |
| * Mandatory attributes: |
| * |
| * o association id - local handle to the SCTP association |
| * |
| * o buffer address - the location where the user message to be |
| * transmitted is stored; |
| * |
| * o byte count - The size of the user data in number of bytes; |
| * |
| * Optional attributes: |
| * |
| * o context - an optional 32 bit integer that will be carried in the |
| * sending failure notification to the ULP if the transportation of |
| * this User Message fails. |
| * |
| * o stream id - to indicate which stream to send the data on. If not |
| * specified, stream 0 will be used. |
| * |
| * o life time - specifies the life time of the user data. The user data |
| * will not be sent by SCTP after the life time expires. This |
| * parameter can be used to avoid efforts to transmit stale |
| * user messages. SCTP notifies the ULP if the data cannot be |
| * initiated to transport (i.e. sent to the destination via SCTP's |
| * send primitive) within the life time variable. However, the |
| * user data will be transmitted if SCTP has attempted to transmit a |
| * chunk before the life time expired. |
| * |
| * o destination transport address - specified as one of the destination |
| * transport addresses of the peer endpoint to which this packet |
| * should be sent. Whenever possible, SCTP should use this destination |
| * transport address for sending the packets, instead of the current |
| * primary path. |
| * |
| * o unorder flag - this flag, if present, indicates that the user |
| * would like the data delivered in an unordered fashion to the peer |
| * (i.e., the U flag is set to 1 on all DATA chunks carrying this |
| * message). |
| * |
| * o no-bundle flag - instructs SCTP not to bundle this user data with |
| * other outbound DATA chunks. SCTP MAY still bundle even when |
| * this flag is present, when faced with network congestion. |
| * |
| * o payload protocol-id - A 32 bit unsigned integer that is to be |
| * passed to the peer indicating the type of payload protocol data |
| * being transmitted. This value is passed as opaque data by SCTP. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_prm_send(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_datamsg *msg = arg; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Process the SHUTDOWN primitive. |
| * |
| * Section: 10.1: |
| * C) Shutdown |
| * |
| * Format: SHUTDOWN(association id) |
| * -> result |
| * |
| * Gracefully closes an association. Any locally queued user data |
| * will be delivered to the peer. The association will be terminated only |
| * after the peer acknowledges all the SCTP packets sent. A success code |
| * will be returned on successful termination of the association. If |
| * attempting to terminate the association results in a failure, an error |
| * code shall be returned. |
| * |
| * Mandatory attributes: |
| * |
| * o association id - local handle to the SCTP association |
| * |
| * Optional attributes: |
| * |
| * None. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_prm_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| enum sctp_disposition disposition; |
| |
| /* From 9.2 Shutdown of an Association |
| * Upon receipt of the SHUTDOWN primitive from its upper |
| * layer, the endpoint enters SHUTDOWN-PENDING state and |
| * remains there until all outstanding data has been |
| * acknowledged by its peer. The endpoint accepts no new data |
| * from its upper layer, but retransmits data to the far end |
| * if necessary to fill gaps. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
| |
| disposition = SCTP_DISPOSITION_CONSUME; |
| if (sctp_outq_is_empty(&asoc->outqueue)) { |
| disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, |
| arg, commands); |
| } |
| |
| return disposition; |
| } |
| |
| /* |
| * Process the ABORT primitive. |
| * |
| * Section: 10.1: |
| * C) Abort |
| * |
| * Format: Abort(association id [, cause code]) |
| * -> result |
| * |
| * Ungracefully closes an association. Any locally queued user data |
| * will be discarded and an ABORT chunk is sent to the peer. A success code |
| * will be returned on successful abortion of the association. If |
| * attempting to abort the association results in a failure, an error |
| * code shall be returned. |
| * |
| * Mandatory attributes: |
| * |
| * o association id - local handle to the SCTP association |
| * |
| * Optional attributes: |
| * |
| * o cause code - reason of the abort to be passed to the peer |
| * |
| * None. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_9_1_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* From 9.1 Abort of an Association |
| * Upon receipt of the ABORT primitive from its upper |
| * layer, the endpoint enters CLOSED state and |
| * discard all outstanding data has been |
| * acknowledged by its peer. The endpoint accepts no new data |
| * from its upper layer, but retransmits data to the far end |
| * if necessary to fill gaps. |
| */ |
| struct sctp_chunk *abort = arg; |
| |
| if (abort) |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| |
| /* Even if we can't send the ABORT due to low memory delete the |
| * TCB. This is a departure from our typical NOMEM handling. |
| */ |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| /* Delete the established association. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| /* We tried an illegal operation on an association which is closed. */ |
| enum sctp_disposition sctp_sf_error_closed(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* We tried an illegal operation on an association which is shutting |
| * down. |
| */ |
| enum sctp_disposition sctp_sf_error_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, |
| SCTP_ERROR(-ESHUTDOWN)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * sctp_cookie_wait_prm_shutdown |
| * |
| * Section: 4 Note: 2 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explicitly address this issue, but is the route through the |
| * state table when someone issues a shutdown while in COOKIE_WAIT state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_cookie_wait_prm_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_CLOSED)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| /* |
| * sctp_cookie_echoed_prm_shutdown |
| * |
| * Section: 4 Note: 2 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explicitly address this issue, but is the route through the |
| * state table when someone issues a shutdown while in COOKIE_ECHOED state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_cookie_echoed_prm_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* There is a single T1 timer, so we should be able to use |
| * common function with the COOKIE-WAIT state. |
| */ |
| return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * sctp_sf_cookie_wait_prm_abort |
| * |
| * Section: 4 Note: 2 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explicitly address this issue, but is the route through the |
| * state table when someone issues an abort while in COOKIE_WAIT state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_cookie_wait_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *abort = arg; |
| |
| /* Stop T1-init timer */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| |
| if (abort) |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_CLOSED)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| |
| /* Even if we can't send the ABORT due to low memory delete the |
| * TCB. This is a departure from our typical NOMEM handling. |
| */ |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNREFUSED)); |
| /* Delete the established association. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
| |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| /* |
| * sctp_sf_cookie_echoed_prm_abort |
| * |
| * Section: 4 Note: 3 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explcitly address this issue, but is the route through the |
| * state table when someone issues an abort while in COOKIE_ECHOED state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_cookie_echoed_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* There is a single T1 timer, so we should be able to use |
| * common function with the COOKIE-WAIT state. |
| */ |
| return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * sctp_sf_shutdown_pending_prm_abort |
| * |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explicitly address this issue, but is the route through the |
| * state table when someone issues an abort while in SHUTDOWN-PENDING state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_shutdown_pending_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* Stop the T5-shutdown guard timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * sctp_sf_shutdown_sent_prm_abort |
| * |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explicitly address this issue, but is the route through the |
| * state table when someone issues an abort while in SHUTDOWN-SENT state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_shutdown_sent_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* Stop the T2-shutdown timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| /* Stop the T5-shutdown guard timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * sctp_sf_cookie_echoed_prm_abort |
| * |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * The RFC does not explcitly address this issue, but is the route through the |
| * state table when someone issues an abort while in COOKIE_ECHOED state. |
| * |
| * Outputs |
| * (timers) |
| */ |
| enum sctp_disposition sctp_sf_shutdown_ack_sent_prm_abort( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| /* The same T2 timer, so we should be able to use |
| * common function with the SHUTDOWN-SENT state. |
| */ |
| return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands); |
| } |
| |
| /* |
| * Process the REQUESTHEARTBEAT primitive |
| * |
| * 10.1 ULP-to-SCTP |
| * J) Request Heartbeat |
| * |
| * Format: REQUESTHEARTBEAT(association id, destination transport address) |
| * |
| * -> result |
| * |
| * Instructs the local endpoint to perform a HeartBeat on the specified |
| * destination transport address of the given association. The returned |
| * result should indicate whether the transmission of the HEARTBEAT |
| * chunk to the destination address is successful. |
| * |
| * Mandatory attributes: |
| * |
| * o association id - local handle to the SCTP association |
| * |
| * o destination transport address - the transport address of the |
| * association on which a heartbeat should be issued. |
| */ |
| enum sctp_disposition sctp_sf_do_prm_requestheartbeat( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type, |
| (struct sctp_transport *)arg, commands)) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* |
| * RFC 2960 (bis), section 8.3 |
| * |
| * D) Request an on-demand HEARTBEAT on a specific destination |
| * transport address of a given association. |
| * |
| * The endpoint should increment the respective error counter of |
| * the destination transport address each time a HEARTBEAT is sent |
| * to that address and not acknowledged within one RTO. |
| * |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT, |
| SCTP_TRANSPORT(arg)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * ADDIP Section 4.1 ASCONF Chunk Procedures |
| * When an endpoint has an ASCONF signaled change to be sent to the |
| * remote endpoint it should do A1 to A9 |
| */ |
| enum sctp_disposition sctp_sf_do_prm_asconf(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */ |
| enum sctp_disposition sctp_sf_do_prm_reconf(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Ignore the primitive event |
| * |
| * The return value is the disposition of the primitive. |
| */ |
| enum sctp_disposition sctp_sf_ignore_primitive( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| pr_debug("%s: primitive type:%d is ignored\n", __func__, |
| type.primitive); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /*************************************************************************** |
| * These are the state functions for the OTHER events. |
| ***************************************************************************/ |
| |
| /* |
| * When the SCTP stack has no more user data to send or retransmit, this |
| * notification is given to the user. Also, at the time when a user app |
| * subscribes to this event, if there is no data to be sent or |
| * retransmit, the stack will immediately send up this notification. |
| */ |
| enum sctp_disposition sctp_sf_do_no_pending_tsn( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_ulpevent *event; |
| |
| event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC); |
| if (!event) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Start the shutdown negotiation. |
| * |
| * From Section 9.2: |
| * Once all its outstanding data has been acknowledged, the endpoint |
| * shall send a SHUTDOWN chunk to its peer including in the Cumulative |
| * TSN Ack field the last sequential TSN it has received from the peer. |
| * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT |
| * state. If the timer expires, the endpoint must re-send the SHUTDOWN |
| * with the updated last sequential TSN received from its peer. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_start_shutdown( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *reply; |
| |
| /* Once all its outstanding data has been acknowledged, the |
| * endpoint shall send a SHUTDOWN chunk to its peer including |
| * in the Cumulative TSN Ack field the last sequential TSN it |
| * has received from the peer. |
| */ |
| reply = sctp_make_shutdown(asoc, arg); |
| if (!reply) |
| goto nomem; |
| |
| /* Set the transport for the SHUTDOWN chunk and the timeout for the |
| * T2-shutdown timer. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| |
| /* It shall then start the T2-shutdown timer */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| /* RFC 4960 Section 9.2 |
| * The sender of the SHUTDOWN MAY also start an overall guard timer |
| * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| |
| if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| |
| /* and enter the SHUTDOWN-SENT state. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); |
| |
| /* sctp-implguide 2.10 Issues with Heartbeating and failover |
| * |
| * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
| * or SHUTDOWN-ACK. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Generate a SHUTDOWN ACK now that everything is SACK'd. |
| * |
| * From Section 9.2: |
| * |
| * If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
| * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, |
| * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the |
| * endpoint must re-send the SHUTDOWN ACK. |
| * |
| * The return value is the disposition. |
| */ |
| enum sctp_disposition sctp_sf_do_9_2_shutdown_ack( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = arg; |
| struct sctp_chunk *reply; |
| |
| /* There are 2 ways of getting here: |
| * 1) called in response to a SHUTDOWN chunk |
| * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. |
| * |
| * For the case (2), the arg parameter is set to NULL. We need |
| * to check that we have a chunk before accessing it's fields. |
| */ |
| if (chunk) { |
| if (!sctp_vtag_verify(chunk, asoc)) |
| return sctp_sf_pdiscard(net, ep, asoc, type, arg, |
| commands); |
| |
| /* Make sure that the SHUTDOWN chunk has a valid length. */ |
| if (!sctp_chunk_length_valid( |
| chunk, sizeof(struct sctp_shutdown_chunk))) |
| return sctp_sf_violation_chunklen(net, ep, asoc, type, |
| arg, commands); |
| } |
| |
| /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
| * shall send a SHUTDOWN ACK ... |
| */ |
| reply = sctp_make_shutdown_ack(asoc, chunk); |
| if (!reply) |
| goto nomem; |
| |
| /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
| * the T2-shutdown timer. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| |
| /* and start/restart a T2-shutdown timer of its own, */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| |
| if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| |
| /* Enter the SHUTDOWN-ACK-SENT state. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); |
| |
| /* sctp-implguide 2.10 Issues with Heartbeating and failover |
| * |
| * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
| * or SHUTDOWN-ACK. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * Ignore the event defined as other |
| * |
| * The return value is the disposition of the event. |
| */ |
| enum sctp_disposition sctp_sf_ignore_other(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| pr_debug("%s: the event other type:%d is ignored\n", |
| __func__, type.other); |
| |
| return SCTP_DISPOSITION_DISCARD; |
| } |
| |
| /************************************************************ |
| * These are the state functions for handling timeout events. |
| ************************************************************/ |
| |
| /* |
| * RTX Timeout |
| * |
| * Section: 6.3.3 Handle T3-rtx Expiration |
| * |
| * Whenever the retransmission timer T3-rtx expires for a destination |
| * address, do the following: |
| * [See below] |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_do_6_3_3_rtx(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_transport *transport = arg; |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS); |
| |
| if (asoc->overall_error_count >= asoc->max_retrans) { |
| if (asoc->peer.zero_window_announced && |
| asoc->state == SCTP_STATE_SHUTDOWN_PENDING) { |
| /* |
| * We are here likely because the receiver had its rwnd |
| * closed for a while and we have not been able to |
| * transmit the locally queued data within the maximum |
| * retransmission attempts limit. Start the T5 |
| * shutdown guard timer to give the receiver one last |
| * chance and some additional time to recover before |
| * aborting. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| } else { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| } |
| |
| /* E1) For the destination address for which the timer |
| * expires, adjust its ssthresh with rules defined in Section |
| * 7.2.3 and set the cwnd <- MTU. |
| */ |
| |
| /* E2) For the destination address for which the timer |
| * expires, set RTO <- RTO * 2 ("back off the timer"). The |
| * maximum value discussed in rule C7 above (RTO.max) may be |
| * used to provide an upper bound to this doubling operation. |
| */ |
| |
| /* E3) Determine how many of the earliest (i.e., lowest TSN) |
| * outstanding DATA chunks for the address for which the |
| * T3-rtx has expired will fit into a single packet, subject |
| * to the MTU constraint for the path corresponding to the |
| * destination transport address to which the retransmission |
| * is being sent (this may be different from the address for |
| * which the timer expires [see Section 6.4]). Call this |
| * value K. Bundle and retransmit those K DATA chunks in a |
| * single packet to the destination endpoint. |
| * |
| * Note: Any DATA chunks that were sent to the address for |
| * which the T3-rtx timer expired but did not fit in one MTU |
| * (rule E3 above), should be marked for retransmission and |
| * sent as soon as cwnd allows (normally when a SACK arrives). |
| */ |
| |
| /* Do some failure management (Section 8.2). */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
| |
| /* NB: Rules E4 and F1 are implicit in R1. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * Generate delayed SACK on timeout |
| * |
| * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
| * |
| * The guidelines on delayed acknowledgement algorithm specified in |
| * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
| * acknowledgement SHOULD be generated for at least every second packet |
| * (not every second DATA chunk) received, and SHOULD be generated |
| * within 200 ms of the arrival of any unacknowledged DATA chunk. In |
| * some situations it may be beneficial for an SCTP transmitter to be |
| * more conservative than the algorithms detailed in this document |
| * allow. However, an SCTP transmitter MUST NOT be more aggressive than |
| * the following algorithms allow. |
| */ |
| enum sctp_disposition sctp_sf_do_6_2_sack(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS); |
| sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * sctp_sf_t1_init_timer_expire |
| * |
| * Section: 4 Note: 2 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * RFC 2960 Section 4 Notes |
| * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT |
| * and re-start the T1-init timer without changing state. This MUST |
| * be repeated up to 'Max.Init.Retransmits' times. After that, the |
| * endpoint MUST abort the initialization process and report the |
| * error to SCTP user. |
| * |
| * Outputs |
| * (timers, events) |
| * |
| */ |
| enum sctp_disposition sctp_sf_t1_init_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| int attempts = asoc->init_err_counter + 1; |
| struct sctp_chunk *repl = NULL; |
| struct sctp_bind_addr *bp; |
| |
| pr_debug("%s: timer T1 expired (INIT)\n", __func__); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS); |
| |
| if (attempts <= asoc->max_init_attempts) { |
| bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
| repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); |
| if (!repl) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| /* Choose transport for INIT. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
| SCTP_CHUNK(repl)); |
| |
| /* Issue a sideeffect to do the needed accounting. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| } else { |
| pr_debug("%s: giving up on INIT, attempts:%d " |
| "max_init_attempts:%d\n", __func__, attempts, |
| asoc->max_init_attempts); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* |
| * sctp_sf_t1_cookie_timer_expire |
| * |
| * Section: 4 Note: 2 |
| * Verification Tag: |
| * Inputs |
| * (endpoint, asoc) |
| * |
| * RFC 2960 Section 4 Notes |
| * 3) If the T1-cookie timer expires, the endpoint MUST retransmit |
| * COOKIE ECHO and re-start the T1-cookie timer without changing |
| * state. This MUST be repeated up to 'Max.Init.Retransmits' times. |
| * After that, the endpoint MUST abort the initialization process and |
| * report the error to SCTP user. |
| * |
| * Outputs |
| * (timers, events) |
| * |
| */ |
| enum sctp_disposition sctp_sf_t1_cookie_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| int attempts = asoc->init_err_counter + 1; |
| struct sctp_chunk *repl = NULL; |
| |
| pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS); |
| |
| if (attempts <= asoc->max_init_attempts) { |
| repl = sctp_make_cookie_echo(asoc, NULL); |
| if (!repl) |
| return SCTP_DISPOSITION_NOMEM; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
| SCTP_CHUNK(repl)); |
| /* Issue a sideeffect to do the needed accounting. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| } else { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN |
| * with the updated last sequential TSN received from its peer. |
| * |
| * An endpoint should limit the number of retransmission of the |
| * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. |
| * If this threshold is exceeded the endpoint should destroy the TCB and |
| * MUST report the peer endpoint unreachable to the upper layer (and |
| * thus the association enters the CLOSED state). The reception of any |
| * packet from its peer (i.e. as the peer sends all of its queued DATA |
| * chunks) should clear the endpoint's retransmission count and restart |
| * the T2-Shutdown timer, giving its peer ample opportunity to transmit |
| * all of its queued DATA chunks that have not yet been sent. |
| */ |
| enum sctp_disposition sctp_sf_t2_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *reply = NULL; |
| |
| pr_debug("%s: timer T2 expired\n", __func__); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS); |
| |
| ((struct sctp_association *)asoc)->shutdown_retries++; |
| |
| if (asoc->overall_error_count >= asoc->max_retrans) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_DELETE_TCB; |
| } |
| |
| switch (asoc->state) { |
| case SCTP_STATE_SHUTDOWN_SENT: |
| reply = sctp_make_shutdown(asoc, NULL); |
| break; |
| |
| case SCTP_STATE_SHUTDOWN_ACK_SENT: |
| reply = sctp_make_shutdown_ack(asoc, NULL); |
| break; |
| |
| default: |
| BUG(); |
| break; |
| } |
| |
| if (!reply) |
| goto nomem; |
| |
| /* Do some failure management (Section 8.2). |
| * If we remove the transport an SHUTDOWN was last sent to, don't |
| * do failure management. |
| */ |
| if (asoc->shutdown_last_sent_to) |
| sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
| SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); |
| |
| /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for |
| * the T2-shutdown timer. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| |
| /* Restart the T2-shutdown timer. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| return SCTP_DISPOSITION_CONSUME; |
| |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* |
| * ADDIP Section 4.1 ASCONF Chunk Procedures |
| * If the T4 RTO timer expires the endpoint should do B1 to B5 |
| */ |
| enum sctp_disposition sctp_sf_t4_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *chunk = asoc->addip_last_asconf; |
| struct sctp_transport *transport = chunk->transport; |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS); |
| |
| /* ADDIP 4.1 B1) Increment the error counters and perform path failure |
| * detection on the appropriate destination address as defined in |
| * RFC2960 [5] section 8.1 and 8.2. |
| */ |
| if (transport) |
| sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
| SCTP_TRANSPORT(transport)); |
| |
| /* Reconfig T4 timer and transport. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
| |
| /* ADDIP 4.1 B2) Increment the association error counters and perform |
| * endpoint failure detection on the association as defined in |
| * RFC2960 [5] section 8.1 and 8.2. |
| * association error counter is incremented in SCTP_CMD_STRIKE. |
| */ |
| if (asoc->overall_error_count >= asoc->max_retrans) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_DISPOSITION_ABORT; |
| } |
| |
| /* ADDIP 4.1 B3) Back-off the destination address RTO value to which |
| * the ASCONF chunk was sent by doubling the RTO timer value. |
| * This is done in SCTP_CMD_STRIKE. |
| */ |
| |
| /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible |
| * choose an alternate destination address (please refer to RFC2960 |
| * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this |
| * chunk, it MUST be the same (including its serial number) as the last |
| * ASCONF sent. |
| */ |
| sctp_chunk_hold(asoc->addip_last_asconf); |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(asoc->addip_last_asconf)); |
| |
| /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different |
| * destination is selected, then the RTO used will be that of the new |
| * destination address. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /* sctpimpguide-05 Section 2.12.2 |
| * The sender of the SHUTDOWN MAY also start an overall guard timer |
| * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
| * At the expiration of this timer the sender SHOULD abort the association |
| * by sending an ABORT chunk. |
| */ |
| enum sctp_disposition sctp_sf_t5_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_chunk *reply = NULL; |
| |
| pr_debug("%s: timer T5 expired\n", __func__); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS); |
| |
| reply = sctp_make_abort(asoc, NULL, 0); |
| if (!reply) |
| goto nomem; |
| |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ETIMEDOUT)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| |
| return SCTP_DISPOSITION_DELETE_TCB; |
| nomem: |
| return SCTP_DISPOSITION_NOMEM; |
| } |
| |
| /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, |
| * the association is automatically closed by starting the shutdown process. |
| * The work that needs to be done is same as when SHUTDOWN is initiated by |
| * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). |
| */ |
| enum sctp_disposition sctp_sf_autoclose_timer_expire( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| enum sctp_disposition disposition; |
| |
| SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS); |
| |
| /* From 9.2 Shutdown of an Association |
| * Upon receipt of the SHUTDOWN primitive from its upper |
| * layer, the endpoint enters SHUTDOWN-PENDING state and |
| * remains there until all outstanding data has been |
| * acknowledged by its peer. The endpoint accepts no new data |
| * from its upper layer, but retransmits data to the far end |
| * if necessary to fill gaps. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
| |
| disposition = SCTP_DISPOSITION_CONSUME; |
| if (sctp_outq_is_empty(&asoc->outqueue)) { |
| disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type, |
| NULL, commands); |
| } |
| |
| return disposition; |
| } |
| |
| /***************************************************************************** |
| * These are sa state functions which could apply to all types of events. |
| ****************************************************************************/ |
| |
| /* |
| * This table entry is not implemented. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_not_impl(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| return SCTP_DISPOSITION_NOT_IMPL; |
| } |
| |
| /* |
| * This table entry represents a bug. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_bug(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, struct sctp_cmd_seq *commands) |
| { |
| return SCTP_DISPOSITION_BUG; |
| } |
| |
| /* |
| * This table entry represents the firing of a timer in the wrong state. |
| * Since timer deletion cannot be guaranteed a timer 'may' end up firing |
| * when the association is in the wrong state. This event should |
| * be ignored, so as to prevent any rearming of the timer. |
| * |
| * Inputs |
| * (endpoint, asoc, chunk) |
| * |
| * The return value is the disposition of the chunk. |
| */ |
| enum sctp_disposition sctp_sf_timer_ignore(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const union sctp_subtype type, |
| void *arg, |
| struct sctp_cmd_seq *commands) |
| { |
| pr_debug("%s: timer %d ignored\n", __func__, type.chunk); |
| |
| return SCTP_DISPOSITION_CONSUME; |
| } |
| |
| /******************************************************************** |
| * 2nd Level Abstractions |
| ********************************************************************/ |
| |
| /* Pull the SACK chunk based on the SACK header. */ |
| static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) |
| { |
| struct sctp_sackhdr *sack; |
| __u16 num_dup_tsns; |
| unsigned int len; |
| __u16 num_blocks; |
| |
| /* Protect ourselves from reading too far into |
| * the skb from a bogus sender. |
| */ |
| sack = (struct sctp_sackhdr *) chunk->skb->data; |
| |
| num_blocks = ntohs(sack->num_gap_ack_blocks); |
| num_dup_tsns = ntohs(sack->num_dup_tsns); |
| len = sizeof(struct sctp_sackhdr); |
| len += (num_blocks + num_dup_tsns) * sizeof(__u32); |
| if (len > chunk->skb->len) |
| return NULL; |
| |
| skb_pull(chunk->skb, len); |
| |
| return sack; |
| } |
| |
| /* Create an ABORT packet to be sent as a response, with the specified |
| * error causes. |
| */ |
| static struct sctp_packet *sctp_abort_pkt_new( |
| struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| const void *payload, size_t paylen) |
| { |
| struct sctp_packet *packet; |
| struct sctp_chunk *abort; |
| |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| |
| if (packet) { |
| /* Make an ABORT. |
| * The T bit will be set if the asoc is NULL. |
| */ |
| abort = sctp_make_abort(asoc, chunk, paylen); |
| if (!abort) { |
| sctp_ootb_pkt_free(packet); |
| return NULL; |
| } |
| |
| /* Reflect vtag if T-Bit is set */ |
| if (sctp_test_T_bit(abort)) |
| packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| |
| /* Add specified error causes, i.e., payload, to the |
| * end of the chunk. |
| */ |
| sctp_addto_chunk(abort, paylen, payload); |
| |
| /* Set the skb to the belonging sock for accounting. */ |
| abort->skb->sk = ep->base.sk; |
| |
| sctp_packet_append_chunk(packet, abort); |
| |
| } |
| |
| return packet; |
| } |
| |
| /* Allocate a packet for responding in the OOTB conditions. */ |
| static struct sctp_packet *sctp_ootb_pkt_new( |
| struct net *net, |
| const struct sctp_association *asoc, |
| const struct sctp_chunk *chunk) |
| { |
| struct sctp_transport *transport; |
| struct sctp_packet *packet; |
| __u16 sport, dport; |
| __u32 vtag; |
| |
| /* Get the source and destination port from the inbound packet. */ |
| sport = ntohs(chunk->sctp_hdr->dest); |
| dport = ntohs(chunk->sctp_hdr->source); |
| |
| /* The V-tag is going to be the same as the inbound packet if no |
| * association exists, otherwise, use the peer's vtag. |
| */ |
| if (asoc) { |
| /* Special case the INIT-ACK as there is no peer's vtag |
| * yet. |
| */ |
| switch (chunk->chunk_hdr->type) { |
| case SCTP_CID_INIT_ACK: |
| { |
| struct sctp_initack_chunk *initack; |
| |
| initack = (struct sctp_initack_chunk *)chunk->chunk_hdr; |
| vtag = ntohl(initack->init_hdr.init_tag); |
| break; |
| } |
| default: |
| vtag = asoc->peer.i.init_tag; |
| break; |
| } |
| } else { |
| /* Special case the INIT and stale COOKIE_ECHO as there is no |
| * vtag yet. |
| */ |
| switch (chunk->chunk_hdr->type) { |
| case SCTP_CID_INIT: |
| { |
| struct sctp_init_chunk *init; |
| |
| init = (struct sctp_init_chunk *)chunk->chunk_hdr; |
| vtag = ntohl(init->init_hdr.init_tag); |
| break; |
| } |
| default: |
| vtag = ntohl(chunk->sctp_hdr->vtag); |
| break; |
| } |
| } |
| |
| /* Make a transport for the bucket, Eliza... */ |
| transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC); |
| if (!transport) |
| goto nomem; |
| |
| transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; |
| |
| /* Cache a route for the transport with the chunk's destination as |
| * the source address. |
| */ |
| sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, |
| sctp_sk(net->sctp.ctl_sock)); |
| |
| packet = &transport->packet; |
| sctp_packet_init(packet, transport, sport, dport); |
| sctp_packet_config(packet, vtag, 0); |
| |
| return packet; |
| |
| nomem: |
| return NULL; |
| } |
| |
| /* Free the packet allocated earlier for responding in the OOTB condition. */ |
| void sctp_ootb_pkt_free(struct sctp_packet *packet) |
| { |
| sctp_transport_free(packet->transport); |
| } |
| |
| /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ |
| static void sctp_send_stale_cookie_err(struct net *net, |
| const struct sctp_endpoint *ep, |
| const struct sctp_association *asoc, |
| const struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands, |
| struct sctp_chunk *err_chunk) |
| { |
| struct sctp_packet *packet; |
| |
| if (err_chunk) { |
| packet = sctp_ootb_pkt_new(net, asoc, chunk); |
| if (packet) { |
| struct sctp_signed_cookie *cookie; |
| |
| /* Override the OOTB vtag from the cookie. */ |
| cookie = chunk->subh.cookie_hdr; |
| packet->vtag = cookie->c.peer_vtag; |
| |
| /* Set the skb to the belonging sock for accounting. */ |
| err_chunk->skb->sk = ep->base.sk; |
| sctp_packet_append_chunk(packet, err_chunk); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| SCTP_PACKET(packet)); |
| SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS); |
| } else |
| sctp_chunk_free (err_chunk); |
| } |
| } |
| |
| |
| /* Process a data chunk */ |
| static int sctp_eat_data(const struct sctp_association *asoc, |
| struct sctp_chunk *chunk, |
| struct sctp_cmd_seq *commands) |
| { |
| struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; |
| struct sock *sk = asoc->base.sk; |
| struct net *net = sock_net(sk); |
| struct sctp_datahdr *data_hdr; |
| struct sctp_chunk *err; |
| enum sctp_verb deliver; |
| size_t datalen; |
| __u32 tsn; |
| int tmp; |
| |
| data_hdr = (struct sctp_datahdr *)chunk->skb->data; |
| chunk->subh.data_hdr = data_hdr; |
| skb_pull(chunk->skb, sctp_datahdr_len(&asoc->stream)); |
| |
| tsn = ntohl(data_hdr->tsn); |
| pr_debug("%s: TSN 0x%x\n", __func__, tsn); |
| |
| /* ASSERT: Now skb->data is really the user data. */ |
| |
| /* Process ECN based congestion. |
| * |
| * Since the chunk structure is reused for all chunks within |
| * a packet, we use ecn_ce_done to track if we've already |
| * done CE processing for this packet. |
| * |
| * We need to do ECN processing even if we plan to discard the |
| * chunk later. |
| */ |
| |
| if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) { |
| struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af; |
| chunk->ecn_ce_done = 1; |
| |
| if (af->is_ce(sctp_gso_headskb(chunk->skb))) { |
| /* Do real work as side effect. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, |
| SCTP_U32(tsn)); |
| } |
| } |
| |
| tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); |
| if (tmp < 0) { |
| /* The TSN is too high--silently discard the chunk and |
| * count on it getting retransmitted later. |
| */ |
| if (chunk->asoc) |
| chunk->asoc->stats.outofseqtsns++; |
| return SCTP_IERROR_HIGH_TSN; |
| } else if (tmp > 0) { |
| /* This is a duplicate. Record it. */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); |
| return SCTP_IERROR_DUP_TSN; |
| } |
| |
| /* This is a new TSN. */ |
| |
| /* Discard if there is no room in the receive window. |
| * Actually, allow a little bit of overflow (up to a MTU). |
| */ |
| datalen = ntohs(chunk->chunk_hdr->length); |
| datalen -= sctp_datachk_len(&asoc->stream); |
| |
| deliver = SCTP_CMD_CHUNK_ULP; |
| |
| /* Think about partial delivery. */ |
| if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { |
| |
| /* Even if we don't accept this chunk there is |
| * memory pressure. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); |
| } |
| |
| /* Spill over rwnd a little bit. Note: While allowed, this spill over |
| * seems a bit troublesome in that frag_point varies based on |
| * PMTU. In cases, such as loopback, this might be a rather |
| * large spill over. |
| */ |
| if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over || |
| (datalen > asoc->rwnd + asoc->frag_point))) { |
| |
| /* If this is the next TSN, consider reneging to make |
| * room. Note: Playing nice with a confused sender. A |
| * malicious sender can still eat up all our buffer |
| * space and in the future we may want to detect and |
| * do more drastic reneging. |
| */ |
| if (sctp_tsnmap_has_gap(map) && |
| (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
| pr_debug("%s: reneging for tsn:%u\n", __func__, tsn); |
| deliver = SCTP_CMD_RENEGE; |
| } else { |
| pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n", |
| __func__, tsn, datalen, asoc->rwnd); |
| |
| return SCTP_IERROR_IGNORE_TSN; |
| } |
| } |
| |
| /* |
| * Also try to renege to limit our memory usage in the event that |
| * we are under memory pressure |
| * If we can't renege, don't worry about it, the sk_rmem_schedule |
| * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our |
| * memory usage too much |
| */ |
| if (sk_under_memory_pressure(sk)) { |
| if (sctp_tsnmap_has_gap(map) && |
| (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
| pr_debug("%s: under pressure, reneging for tsn:%u\n", |
| __func__, tsn); |
| deliver = SCTP_CMD_RENEGE; |
| } else { |
| sk_mem_reclaim(sk); |
| } |
| } |
| |
| /* |
| * Section 3.3.10.9 No User Data (9) |
| * |
| * Cause of error |
| * --------------- |
| * No User Data: This error cause is returned to the originator of a |
| * DATA chunk if a received DATA chunk has no user data. |
| */ |
| if (unlikely(0 == datalen)) { |
| err = sctp_make_abort_no_data(asoc, chunk, tsn); |
| if (err) { |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err)); |
| } |
| /* We are going to ABORT, so we might as well stop |
| * processing the rest of the chunks in the packet. |
| */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| SCTP_ERROR(ECONNABORTED)); |
| sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| SCTP_PERR(SCTP_ERROR_NO_DATA)); |
| SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); |
| SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); |
| return SCTP_IERROR_NO_DATA; |
| } |
| |
| chunk->data_accepted = 1; |
| |
| /* Note: Some chunks may get overcounted (if we drop) or overcounted |
| * if we renege and the chunk arrives again. |
| */ |
| if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { |
| SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS); |
| if (chunk->asoc) |
| chunk->asoc->stats.iuodchunks++; |
| } else { |
| SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS); |
| if (chunk->asoc) |
| chunk->asoc->stats.iodchunks++; |
| } |
| |
| /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number |
| * |
| * If an endpoint receive a DATA chunk with an invalid stream |
| * identifier, it shall acknowledge the reception of the DATA chunk |
| * following the normal procedure, immediately send an ERROR chunk |
| * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) |
| * and discard the DATA chunk. |
| */ |
| if (ntohs(data_hdr->stream) >= asoc->stream.incnt) { |
| /* Mark tsn as received even though we drop it */ |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); |
| |
| err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, |
| &data_hdr->stream, |
| sizeof(data_hdr->stream), |
| sizeof(u16)); |
| if (err) |
| sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| SCTP_CHUNK(err)); |
| return SCTP_IERROR_BAD_STREAM; |
| } |
| |
| /* Check to see if the SSN is possible for this TSN. |
| * The biggest gap we can record is 4K wide. Since SSNs wrap |
| * at an unsigned short, there is no way that an SSN can |
| * wrap and for a valid TSN. We can simply check if the current |
| * SSN is smaller then the next expected one. If it is, it wrapped |
| * and is invalid. |
| */ |
| if (!asoc->stream.si->validate_data(chunk)) |
| return SCTP_IERROR_PROTO_VIOLATION; |
| |
| /* Send the data up to the user. Note: Schedule the |
| * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK |
| * chunk needs the updated rwnd. |
| */ |
| sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); |
| |
| return SCTP_IERROR_NO_ERROR; |
| } |