| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Connection tracking protocol helper module for SCTP. |
| * |
| * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com> |
| * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net> |
| * |
| * SCTP is defined in RFC 2960. References to various sections in this code |
| * are to this RFC. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/timer.h> |
| #include <linux/netfilter.h> |
| #include <linux/in.h> |
| #include <linux/ip.h> |
| #include <linux/sctp.h> |
| #include <linux/string.h> |
| #include <linux/seq_file.h> |
| #include <linux/spinlock.h> |
| #include <linux/interrupt.h> |
| #include <net/sctp/checksum.h> |
| |
| #include <net/netfilter/nf_log.h> |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_l4proto.h> |
| #include <net/netfilter/nf_conntrack_ecache.h> |
| #include <net/netfilter/nf_conntrack_timeout.h> |
| |
| /* FIXME: Examine ipfilter's timeouts and conntrack transitions more |
| closely. They're more complex. --RR |
| |
| And so for me for SCTP :D -Kiran */ |
| |
| static const char *const sctp_conntrack_names[] = { |
| "NONE", |
| "CLOSED", |
| "COOKIE_WAIT", |
| "COOKIE_ECHOED", |
| "ESTABLISHED", |
| "SHUTDOWN_SENT", |
| "SHUTDOWN_RECD", |
| "SHUTDOWN_ACK_SENT", |
| "HEARTBEAT_SENT", |
| "HEARTBEAT_ACKED", |
| }; |
| |
| #define SECS * HZ |
| #define MINS * 60 SECS |
| #define HOURS * 60 MINS |
| #define DAYS * 24 HOURS |
| |
| static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = { |
| [SCTP_CONNTRACK_CLOSED] = 10 SECS, |
| [SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS, |
| [SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS, |
| [SCTP_CONNTRACK_ESTABLISHED] = 5 DAYS, |
| [SCTP_CONNTRACK_SHUTDOWN_SENT] = 300 SECS / 1000, |
| [SCTP_CONNTRACK_SHUTDOWN_RECD] = 300 SECS / 1000, |
| [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS, |
| [SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS, |
| [SCTP_CONNTRACK_HEARTBEAT_ACKED] = 210 SECS, |
| }; |
| |
| #define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1 |
| |
| #define sNO SCTP_CONNTRACK_NONE |
| #define sCL SCTP_CONNTRACK_CLOSED |
| #define sCW SCTP_CONNTRACK_COOKIE_WAIT |
| #define sCE SCTP_CONNTRACK_COOKIE_ECHOED |
| #define sES SCTP_CONNTRACK_ESTABLISHED |
| #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT |
| #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD |
| #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT |
| #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT |
| #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED |
| #define sIV SCTP_CONNTRACK_MAX |
| |
| /* |
| These are the descriptions of the states: |
| |
| NOTE: These state names are tantalizingly similar to the states of an |
| SCTP endpoint. But the interpretation of the states is a little different, |
| considering that these are the states of the connection and not of an end |
| point. Please note the subtleties. -Kiran |
| |
| NONE - Nothing so far. |
| COOKIE WAIT - We have seen an INIT chunk in the original direction, or also |
| an INIT_ACK chunk in the reply direction. |
| COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction. |
| ESTABLISHED - We have seen a COOKIE_ACK in the reply direction. |
| SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction. |
| SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply directoin. |
| SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite |
| to that of the SHUTDOWN chunk. |
| CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of |
| the SHUTDOWN chunk. Connection is closed. |
| HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow. |
| HEARTBEAT_ACKED - We have seen a HEARTBEAT-ACK in the direction opposite to |
| that of the HEARTBEAT chunk. Secondary connection is |
| established. |
| */ |
| |
| /* TODO |
| - I have assumed that the first INIT is in the original direction. |
| This messes things when an INIT comes in the reply direction in CLOSED |
| state. |
| - Check the error type in the reply dir before transitioning from |
| cookie echoed to closed. |
| - Sec 5.2.4 of RFC 2960 |
| - Full Multi Homing support. |
| */ |
| |
| /* SCTP conntrack state transitions */ |
| static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = { |
| { |
| /* ORIGINAL */ |
| /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */ |
| /* init */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA}, |
| /* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA}, |
| /* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL}, |
| /* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS}, |
| /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA}, |
| /* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/ |
| /* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */ |
| /* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */ |
| /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA}, |
| /* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}, |
| /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA} |
| }, |
| { |
| /* REPLY */ |
| /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */ |
| /* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */ |
| /* init_ack */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA}, |
| /* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL}, |
| /* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR}, |
| /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA}, |
| /* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA}, |
| /* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */ |
| /* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA}, |
| /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA}, |
| /* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}, |
| /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA} |
| } |
| }; |
| |
| #ifdef CONFIG_NF_CONNTRACK_PROCFS |
| /* Print out the private part of the conntrack. */ |
| static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct) |
| { |
| seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]); |
| } |
| #endif |
| |
| #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \ |
| for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \ |
| (offset) < (skb)->len && \ |
| ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \ |
| (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++) |
| |
| /* Some validity checks to make sure the chunks are fine */ |
| static int do_basic_checks(struct nf_conn *ct, |
| const struct sk_buff *skb, |
| unsigned int dataoff, |
| unsigned long *map) |
| { |
| u_int32_t offset, count; |
| struct sctp_chunkhdr _sch, *sch; |
| int flag; |
| |
| flag = 0; |
| |
| for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { |
| pr_debug("Chunk Num: %d Type: %d\n", count, sch->type); |
| |
| if (sch->type == SCTP_CID_INIT || |
| sch->type == SCTP_CID_INIT_ACK || |
| sch->type == SCTP_CID_SHUTDOWN_COMPLETE) |
| flag = 1; |
| |
| /* |
| * Cookie Ack/Echo chunks not the first OR |
| * Init / Init Ack / Shutdown compl chunks not the only chunks |
| * OR zero-length. |
| */ |
| if (((sch->type == SCTP_CID_COOKIE_ACK || |
| sch->type == SCTP_CID_COOKIE_ECHO || |
| flag) && |
| count != 0) || !sch->length) { |
| pr_debug("Basic checks failed\n"); |
| return 1; |
| } |
| |
| if (map) |
| set_bit(sch->type, map); |
| } |
| |
| pr_debug("Basic checks passed\n"); |
| return count == 0; |
| } |
| |
| static int sctp_new_state(enum ip_conntrack_dir dir, |
| enum sctp_conntrack cur_state, |
| int chunk_type) |
| { |
| int i; |
| |
| pr_debug("Chunk type: %d\n", chunk_type); |
| |
| switch (chunk_type) { |
| case SCTP_CID_INIT: |
| pr_debug("SCTP_CID_INIT\n"); |
| i = 0; |
| break; |
| case SCTP_CID_INIT_ACK: |
| pr_debug("SCTP_CID_INIT_ACK\n"); |
| i = 1; |
| break; |
| case SCTP_CID_ABORT: |
| pr_debug("SCTP_CID_ABORT\n"); |
| i = 2; |
| break; |
| case SCTP_CID_SHUTDOWN: |
| pr_debug("SCTP_CID_SHUTDOWN\n"); |
| i = 3; |
| break; |
| case SCTP_CID_SHUTDOWN_ACK: |
| pr_debug("SCTP_CID_SHUTDOWN_ACK\n"); |
| i = 4; |
| break; |
| case SCTP_CID_ERROR: |
| pr_debug("SCTP_CID_ERROR\n"); |
| i = 5; |
| break; |
| case SCTP_CID_COOKIE_ECHO: |
| pr_debug("SCTP_CID_COOKIE_ECHO\n"); |
| i = 6; |
| break; |
| case SCTP_CID_COOKIE_ACK: |
| pr_debug("SCTP_CID_COOKIE_ACK\n"); |
| i = 7; |
| break; |
| case SCTP_CID_SHUTDOWN_COMPLETE: |
| pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n"); |
| i = 8; |
| break; |
| case SCTP_CID_HEARTBEAT: |
| pr_debug("SCTP_CID_HEARTBEAT"); |
| i = 9; |
| break; |
| case SCTP_CID_HEARTBEAT_ACK: |
| pr_debug("SCTP_CID_HEARTBEAT_ACK"); |
| i = 10; |
| break; |
| default: |
| /* Other chunks like DATA or SACK do not change the state */ |
| pr_debug("Unknown chunk type, Will stay in %s\n", |
| sctp_conntrack_names[cur_state]); |
| return cur_state; |
| } |
| |
| pr_debug("dir: %d cur_state: %s chunk_type: %d new_state: %s\n", |
| dir, sctp_conntrack_names[cur_state], chunk_type, |
| sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]); |
| |
| return sctp_conntracks[dir][i][cur_state]; |
| } |
| |
| /* Don't need lock here: this conntrack not in circulation yet */ |
| static noinline bool |
| sctp_new(struct nf_conn *ct, const struct sk_buff *skb, |
| const struct sctphdr *sh, unsigned int dataoff) |
| { |
| enum sctp_conntrack new_state; |
| const struct sctp_chunkhdr *sch; |
| struct sctp_chunkhdr _sch; |
| u32 offset, count; |
| |
| memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp)); |
| new_state = SCTP_CONNTRACK_MAX; |
| for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) { |
| new_state = sctp_new_state(IP_CT_DIR_ORIGINAL, |
| SCTP_CONNTRACK_NONE, sch->type); |
| |
| /* Invalid: delete conntrack */ |
| if (new_state == SCTP_CONNTRACK_NONE || |
| new_state == SCTP_CONNTRACK_MAX) { |
| pr_debug("nf_conntrack_sctp: invalid new deleting.\n"); |
| return false; |
| } |
| |
| /* Copy the vtag into the state info */ |
| if (sch->type == SCTP_CID_INIT) { |
| struct sctp_inithdr _inithdr, *ih; |
| /* Sec 8.5.1 (A) */ |
| if (sh->vtag) |
| return false; |
| |
| ih = skb_header_pointer(skb, offset + sizeof(_sch), |
| sizeof(_inithdr), &_inithdr); |
| if (!ih) |
| return false; |
| |
| pr_debug("Setting vtag %x for new conn\n", |
| ih->init_tag); |
| |
| ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag; |
| } else if (sch->type == SCTP_CID_HEARTBEAT) { |
| pr_debug("Setting vtag %x for secondary conntrack\n", |
| sh->vtag); |
| ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag; |
| } else { |
| /* If it is a shutdown ack OOTB packet, we expect a return |
| shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ |
| pr_debug("Setting vtag %x for new conn OOTB\n", |
| sh->vtag); |
| ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag; |
| } |
| |
| ct->proto.sctp.state = SCTP_CONNTRACK_NONE; |
| } |
| |
| return true; |
| } |
| |
| static bool sctp_error(struct sk_buff *skb, |
| unsigned int dataoff, |
| const struct nf_hook_state *state) |
| { |
| const struct sctphdr *sh; |
| const char *logmsg; |
| |
| if (skb->len < dataoff + sizeof(struct sctphdr)) { |
| logmsg = "nf_ct_sctp: short packet "; |
| goto out_invalid; |
| } |
| if (state->hook == NF_INET_PRE_ROUTING && |
| state->net->ct.sysctl_checksum && |
| skb->ip_summed == CHECKSUM_NONE) { |
| if (skb_ensure_writable(skb, dataoff + sizeof(*sh))) { |
| logmsg = "nf_ct_sctp: failed to read header "; |
| goto out_invalid; |
| } |
| sh = (const struct sctphdr *)(skb->data + dataoff); |
| if (sh->checksum != sctp_compute_cksum(skb, dataoff)) { |
| logmsg = "nf_ct_sctp: bad CRC "; |
| goto out_invalid; |
| } |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| } |
| return false; |
| out_invalid: |
| nf_l4proto_log_invalid(skb, state, IPPROTO_SCTP, "%s", logmsg); |
| return true; |
| } |
| |
| /* Returns verdict for packet, or -NF_ACCEPT for invalid. */ |
| int nf_conntrack_sctp_packet(struct nf_conn *ct, |
| struct sk_buff *skb, |
| unsigned int dataoff, |
| enum ip_conntrack_info ctinfo, |
| const struct nf_hook_state *state) |
| { |
| enum sctp_conntrack new_state, old_state; |
| enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
| const struct sctphdr *sh; |
| struct sctphdr _sctph; |
| const struct sctp_chunkhdr *sch; |
| struct sctp_chunkhdr _sch; |
| u_int32_t offset, count; |
| unsigned int *timeouts; |
| unsigned long map[256 / sizeof(unsigned long)] = { 0 }; |
| bool ignore = false; |
| |
| if (sctp_error(skb, dataoff, state)) |
| return -NF_ACCEPT; |
| |
| sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); |
| if (sh == NULL) |
| goto out; |
| |
| if (do_basic_checks(ct, skb, dataoff, map) != 0) |
| goto out; |
| |
| if (!nf_ct_is_confirmed(ct)) { |
| /* If an OOTB packet has any of these chunks discard (Sec 8.4) */ |
| if (test_bit(SCTP_CID_ABORT, map) || |
| test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) || |
| test_bit(SCTP_CID_COOKIE_ACK, map)) |
| return -NF_ACCEPT; |
| |
| if (!sctp_new(ct, skb, sh, dataoff)) |
| return -NF_ACCEPT; |
| } |
| |
| /* Check the verification tag (Sec 8.5) */ |
| if (!test_bit(SCTP_CID_INIT, map) && |
| !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) && |
| !test_bit(SCTP_CID_COOKIE_ECHO, map) && |
| !test_bit(SCTP_CID_ABORT, map) && |
| !test_bit(SCTP_CID_SHUTDOWN_ACK, map) && |
| !test_bit(SCTP_CID_HEARTBEAT, map) && |
| !test_bit(SCTP_CID_HEARTBEAT_ACK, map) && |
| sh->vtag != ct->proto.sctp.vtag[dir]) { |
| pr_debug("Verification tag check failed\n"); |
| goto out; |
| } |
| |
| old_state = new_state = SCTP_CONNTRACK_NONE; |
| spin_lock_bh(&ct->lock); |
| for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { |
| /* Special cases of Verification tag check (Sec 8.5.1) */ |
| if (sch->type == SCTP_CID_INIT) { |
| /* Sec 8.5.1 (A) */ |
| if (sh->vtag != 0) |
| goto out_unlock; |
| } else if (sch->type == SCTP_CID_ABORT) { |
| /* Sec 8.5.1 (B) */ |
| if (sh->vtag != ct->proto.sctp.vtag[dir] && |
| sh->vtag != ct->proto.sctp.vtag[!dir]) |
| goto out_unlock; |
| } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) { |
| /* Sec 8.5.1 (C) */ |
| if (sh->vtag != ct->proto.sctp.vtag[dir] && |
| sh->vtag != ct->proto.sctp.vtag[!dir] && |
| sch->flags & SCTP_CHUNK_FLAG_T) |
| goto out_unlock; |
| } else if (sch->type == SCTP_CID_COOKIE_ECHO) { |
| /* Sec 8.5.1 (D) */ |
| if (sh->vtag != ct->proto.sctp.vtag[dir]) |
| goto out_unlock; |
| } else if (sch->type == SCTP_CID_HEARTBEAT) { |
| if (ct->proto.sctp.vtag[dir] == 0) { |
| pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir); |
| ct->proto.sctp.vtag[dir] = sh->vtag; |
| } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { |
| if (test_bit(SCTP_CID_DATA, map) || ignore) |
| goto out_unlock; |
| |
| ct->proto.sctp.flags |= SCTP_FLAG_HEARTBEAT_VTAG_FAILED; |
| ct->proto.sctp.last_dir = dir; |
| ignore = true; |
| continue; |
| } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { |
| ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; |
| } |
| } else if (sch->type == SCTP_CID_HEARTBEAT_ACK) { |
| if (ct->proto.sctp.vtag[dir] == 0) { |
| pr_debug("Setting vtag %x for dir %d\n", |
| sh->vtag, dir); |
| ct->proto.sctp.vtag[dir] = sh->vtag; |
| } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { |
| if (test_bit(SCTP_CID_DATA, map) || ignore) |
| goto out_unlock; |
| |
| if ((ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) == 0 || |
| ct->proto.sctp.last_dir == dir) |
| goto out_unlock; |
| |
| ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; |
| ct->proto.sctp.vtag[dir] = sh->vtag; |
| ct->proto.sctp.vtag[!dir] = 0; |
| } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { |
| ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; |
| } |
| } |
| |
| old_state = ct->proto.sctp.state; |
| new_state = sctp_new_state(dir, old_state, sch->type); |
| |
| /* Invalid */ |
| if (new_state == SCTP_CONNTRACK_MAX) { |
| pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u " |
| "conntrack=%u\n", |
| dir, sch->type, old_state); |
| goto out_unlock; |
| } |
| |
| /* If it is an INIT or an INIT ACK note down the vtag */ |
| if (sch->type == SCTP_CID_INIT || |
| sch->type == SCTP_CID_INIT_ACK) { |
| struct sctp_inithdr _inithdr, *ih; |
| |
| ih = skb_header_pointer(skb, offset + sizeof(_sch), |
| sizeof(_inithdr), &_inithdr); |
| if (ih == NULL) |
| goto out_unlock; |
| pr_debug("Setting vtag %x for dir %d\n", |
| ih->init_tag, !dir); |
| ct->proto.sctp.vtag[!dir] = ih->init_tag; |
| } |
| |
| ct->proto.sctp.state = new_state; |
| if (old_state != new_state) |
| nf_conntrack_event_cache(IPCT_PROTOINFO, ct); |
| } |
| spin_unlock_bh(&ct->lock); |
| |
| /* allow but do not refresh timeout */ |
| if (ignore) |
| return NF_ACCEPT; |
| |
| timeouts = nf_ct_timeout_lookup(ct); |
| if (!timeouts) |
| timeouts = nf_sctp_pernet(nf_ct_net(ct))->timeouts; |
| |
| nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]); |
| |
| if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED && |
| dir == IP_CT_DIR_REPLY && |
| new_state == SCTP_CONNTRACK_ESTABLISHED) { |
| pr_debug("Setting assured bit\n"); |
| set_bit(IPS_ASSURED_BIT, &ct->status); |
| nf_conntrack_event_cache(IPCT_ASSURED, ct); |
| } |
| |
| return NF_ACCEPT; |
| |
| out_unlock: |
| spin_unlock_bh(&ct->lock); |
| out: |
| return -NF_ACCEPT; |
| } |
| |
| static bool sctp_can_early_drop(const struct nf_conn *ct) |
| { |
| switch (ct->proto.sctp.state) { |
| case SCTP_CONNTRACK_SHUTDOWN_SENT: |
| case SCTP_CONNTRACK_SHUTDOWN_RECD: |
| case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT: |
| return true; |
| default: |
| break; |
| } |
| |
| return false; |
| } |
| |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| |
| #include <linux/netfilter/nfnetlink.h> |
| #include <linux/netfilter/nfnetlink_conntrack.h> |
| |
| static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla, |
| struct nf_conn *ct, bool destroy) |
| { |
| struct nlattr *nest_parms; |
| |
| spin_lock_bh(&ct->lock); |
| nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP); |
| if (!nest_parms) |
| goto nla_put_failure; |
| |
| if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state)) |
| goto nla_put_failure; |
| |
| if (destroy) |
| goto skip_state; |
| |
| if (nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL, |
| ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) || |
| nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY, |
| ct->proto.sctp.vtag[IP_CT_DIR_REPLY])) |
| goto nla_put_failure; |
| |
| skip_state: |
| spin_unlock_bh(&ct->lock); |
| nla_nest_end(skb, nest_parms); |
| |
| return 0; |
| |
| nla_put_failure: |
| spin_unlock_bh(&ct->lock); |
| return -1; |
| } |
| |
| static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = { |
| [CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 }, |
| [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 }, |
| [CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 }, |
| }; |
| |
| #define SCTP_NLATTR_SIZE ( \ |
| NLA_ALIGN(NLA_HDRLEN + 1) + \ |
| NLA_ALIGN(NLA_HDRLEN + 4) + \ |
| NLA_ALIGN(NLA_HDRLEN + 4)) |
| |
| static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct) |
| { |
| struct nlattr *attr = cda[CTA_PROTOINFO_SCTP]; |
| struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1]; |
| int err; |
| |
| /* updates may not contain the internal protocol info, skip parsing */ |
| if (!attr) |
| return 0; |
| |
| err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_SCTP_MAX, attr, |
| sctp_nla_policy, NULL); |
| if (err < 0) |
| return err; |
| |
| if (!tb[CTA_PROTOINFO_SCTP_STATE] || |
| !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] || |
| !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]) |
| return -EINVAL; |
| |
| spin_lock_bh(&ct->lock); |
| ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]); |
| ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = |
| nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]); |
| ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = |
| nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]); |
| spin_unlock_bh(&ct->lock); |
| |
| return 0; |
| } |
| #endif |
| |
| #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
| |
| #include <linux/netfilter/nfnetlink.h> |
| #include <linux/netfilter/nfnetlink_cttimeout.h> |
| |
| static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[], |
| struct net *net, void *data) |
| { |
| unsigned int *timeouts = data; |
| struct nf_sctp_net *sn = nf_sctp_pernet(net); |
| int i; |
| |
| if (!timeouts) |
| timeouts = sn->timeouts; |
| |
| /* set default SCTP timeouts. */ |
| for (i=0; i<SCTP_CONNTRACK_MAX; i++) |
| timeouts[i] = sn->timeouts[i]; |
| |
| /* there's a 1:1 mapping between attributes and protocol states. */ |
| for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) { |
| if (tb[i]) { |
| timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ; |
| } |
| } |
| |
| timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED]; |
| return 0; |
| } |
| |
| static int |
| sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) |
| { |
| const unsigned int *timeouts = data; |
| int i; |
| |
| for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) { |
| if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ))) |
| goto nla_put_failure; |
| } |
| return 0; |
| |
| nla_put_failure: |
| return -ENOSPC; |
| } |
| |
| static const struct nla_policy |
| sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = { |
| [CTA_TIMEOUT_SCTP_CLOSED] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_COOKIE_WAIT] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_COOKIE_ECHOED] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_ESTABLISHED] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT] = { .type = NLA_U32 }, |
| [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED] = { .type = NLA_U32 }, |
| }; |
| #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
| |
| void nf_conntrack_sctp_init_net(struct net *net) |
| { |
| struct nf_sctp_net *sn = nf_sctp_pernet(net); |
| int i; |
| |
| for (i = 0; i < SCTP_CONNTRACK_MAX; i++) |
| sn->timeouts[i] = sctp_timeouts[i]; |
| |
| /* timeouts[0] is unused, init it so ->timeouts[0] contains |
| * 'new' timeout, like udp or icmp. |
| */ |
| sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED]; |
| } |
| |
| const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = { |
| .l4proto = IPPROTO_SCTP, |
| #ifdef CONFIG_NF_CONNTRACK_PROCFS |
| .print_conntrack = sctp_print_conntrack, |
| #endif |
| .can_early_drop = sctp_can_early_drop, |
| #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
| .nlattr_size = SCTP_NLATTR_SIZE, |
| .to_nlattr = sctp_to_nlattr, |
| .from_nlattr = nlattr_to_sctp, |
| .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
| .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, |
| .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
| .nla_policy = nf_ct_port_nla_policy, |
| #endif |
| #ifdef CONFIG_NF_CONNTRACK_TIMEOUT |
| .ctnl_timeout = { |
| .nlattr_to_obj = sctp_timeout_nlattr_to_obj, |
| .obj_to_nlattr = sctp_timeout_obj_to_nlattr, |
| .nlattr_max = CTA_TIMEOUT_SCTP_MAX, |
| .obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX, |
| .nla_policy = sctp_timeout_nla_policy, |
| }, |
| #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ |
| }; |