| /* Peer event handling, typically ICMP messages. |
| * |
| * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/net.h> |
| #include <linux/skbuff.h> |
| #include <linux/errqueue.h> |
| #include <linux/udp.h> |
| #include <linux/in.h> |
| #include <linux/in6.h> |
| #include <linux/icmp.h> |
| #include <net/sock.h> |
| #include <net/af_rxrpc.h> |
| #include <net/ip.h> |
| #include "ar-internal.h" |
| |
| static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *); |
| |
| /* |
| * Find the peer associated with an ICMP packet. |
| */ |
| static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local, |
| const struct sk_buff *skb) |
| { |
| struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); |
| struct sockaddr_rxrpc srx; |
| |
| _enter(""); |
| |
| memset(&srx, 0, sizeof(srx)); |
| srx.transport_type = local->srx.transport_type; |
| srx.transport_len = local->srx.transport_len; |
| srx.transport.family = local->srx.transport.family; |
| |
| /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice |
| * versa? |
| */ |
| switch (srx.transport.family) { |
| case AF_INET: |
| srx.transport.sin.sin_port = serr->port; |
| switch (serr->ee.ee_origin) { |
| case SO_EE_ORIGIN_ICMP: |
| _net("Rx ICMP"); |
| memcpy(&srx.transport.sin.sin_addr, |
| skb_network_header(skb) + serr->addr_offset, |
| sizeof(struct in_addr)); |
| break; |
| case SO_EE_ORIGIN_ICMP6: |
| _net("Rx ICMP6 on v4 sock"); |
| memcpy(&srx.transport.sin.sin_addr, |
| skb_network_header(skb) + serr->addr_offset + 12, |
| sizeof(struct in_addr)); |
| break; |
| default: |
| memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr, |
| sizeof(struct in_addr)); |
| break; |
| } |
| break; |
| |
| #ifdef CONFIG_AF_RXRPC_IPV6 |
| case AF_INET6: |
| srx.transport.sin6.sin6_port = serr->port; |
| switch (serr->ee.ee_origin) { |
| case SO_EE_ORIGIN_ICMP6: |
| _net("Rx ICMP6"); |
| memcpy(&srx.transport.sin6.sin6_addr, |
| skb_network_header(skb) + serr->addr_offset, |
| sizeof(struct in6_addr)); |
| break; |
| case SO_EE_ORIGIN_ICMP: |
| _net("Rx ICMP on v6 sock"); |
| srx.transport.sin6.sin6_addr.s6_addr32[0] = 0; |
| srx.transport.sin6.sin6_addr.s6_addr32[1] = 0; |
| srx.transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff); |
| memcpy(srx.transport.sin6.sin6_addr.s6_addr + 12, |
| skb_network_header(skb) + serr->addr_offset, |
| sizeof(struct in_addr)); |
| break; |
| default: |
| memcpy(&srx.transport.sin6.sin6_addr, |
| &ipv6_hdr(skb)->saddr, |
| sizeof(struct in6_addr)); |
| break; |
| } |
| break; |
| #endif |
| |
| default: |
| BUG(); |
| } |
| |
| return rxrpc_lookup_peer_rcu(local, &srx); |
| } |
| |
| /* |
| * Handle an MTU/fragmentation problem. |
| */ |
| static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr) |
| { |
| u32 mtu = serr->ee.ee_info; |
| |
| _net("Rx ICMP Fragmentation Needed (%d)", mtu); |
| |
| /* wind down the local interface MTU */ |
| if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { |
| peer->if_mtu = mtu; |
| _net("I/F MTU %u", mtu); |
| } |
| |
| if (mtu == 0) { |
| /* they didn't give us a size, estimate one */ |
| mtu = peer->if_mtu; |
| if (mtu > 1500) { |
| mtu >>= 1; |
| if (mtu < 1500) |
| mtu = 1500; |
| } else { |
| mtu -= 100; |
| if (mtu < peer->hdrsize) |
| mtu = peer->hdrsize + 4; |
| } |
| } |
| |
| if (mtu < peer->mtu) { |
| spin_lock_bh(&peer->lock); |
| peer->mtu = mtu; |
| peer->maxdata = peer->mtu - peer->hdrsize; |
| spin_unlock_bh(&peer->lock); |
| _net("Net MTU %u (maxdata %u)", |
| peer->mtu, peer->maxdata); |
| } |
| } |
| |
| /* |
| * Handle an error received on the local endpoint. |
| */ |
| void rxrpc_error_report(struct sock *sk) |
| { |
| struct sock_exterr_skb *serr; |
| struct rxrpc_local *local = sk->sk_user_data; |
| struct rxrpc_peer *peer; |
| struct sk_buff *skb; |
| |
| _enter("%p{%d}", sk, local->debug_id); |
| |
| skb = sock_dequeue_err_skb(sk); |
| if (!skb) { |
| _leave("UDP socket errqueue empty"); |
| return; |
| } |
| rxrpc_new_skb(skb, rxrpc_skb_rx_received); |
| serr = SKB_EXT_ERR(skb); |
| if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { |
| _leave("UDP empty message"); |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| return; |
| } |
| |
| rcu_read_lock(); |
| peer = rxrpc_lookup_peer_icmp_rcu(local, skb); |
| if (peer && !rxrpc_get_peer_maybe(peer)) |
| peer = NULL; |
| if (!peer) { |
| rcu_read_unlock(); |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| _leave(" [no peer]"); |
| return; |
| } |
| |
| if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && |
| serr->ee.ee_type == ICMP_DEST_UNREACH && |
| serr->ee.ee_code == ICMP_FRAG_NEEDED)) { |
| rxrpc_adjust_mtu(peer, serr); |
| rcu_read_unlock(); |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| rxrpc_put_peer(peer); |
| _leave(" [MTU update]"); |
| return; |
| } |
| |
| rxrpc_store_error(peer, serr); |
| rcu_read_unlock(); |
| rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
| |
| /* The ref we obtained is passed off to the work item */ |
| __rxrpc_queue_peer_error(peer); |
| _leave(""); |
| } |
| |
| /* |
| * Map an error report to error codes on the peer record. |
| */ |
| static void rxrpc_store_error(struct rxrpc_peer *peer, |
| struct sock_exterr_skb *serr) |
| { |
| struct sock_extended_err *ee; |
| int err; |
| |
| _enter(""); |
| |
| ee = &serr->ee; |
| |
| _net("Rx Error o=%d t=%d c=%d e=%d", |
| ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno); |
| |
| err = ee->ee_errno; |
| |
| switch (ee->ee_origin) { |
| case SO_EE_ORIGIN_ICMP: |
| switch (ee->ee_type) { |
| case ICMP_DEST_UNREACH: |
| switch (ee->ee_code) { |
| case ICMP_NET_UNREACH: |
| _net("Rx Received ICMP Network Unreachable"); |
| break; |
| case ICMP_HOST_UNREACH: |
| _net("Rx Received ICMP Host Unreachable"); |
| break; |
| case ICMP_PORT_UNREACH: |
| _net("Rx Received ICMP Port Unreachable"); |
| break; |
| case ICMP_NET_UNKNOWN: |
| _net("Rx Received ICMP Unknown Network"); |
| break; |
| case ICMP_HOST_UNKNOWN: |
| _net("Rx Received ICMP Unknown Host"); |
| break; |
| default: |
| _net("Rx Received ICMP DestUnreach code=%u", |
| ee->ee_code); |
| break; |
| } |
| break; |
| |
| case ICMP_TIME_EXCEEDED: |
| _net("Rx Received ICMP TTL Exceeded"); |
| break; |
| |
| default: |
| _proto("Rx Received ICMP error { type=%u code=%u }", |
| ee->ee_type, ee->ee_code); |
| break; |
| } |
| break; |
| |
| case SO_EE_ORIGIN_NONE: |
| case SO_EE_ORIGIN_LOCAL: |
| _proto("Rx Received local error { error=%d }", err); |
| err += RXRPC_LOCAL_ERROR_OFFSET; |
| break; |
| |
| case SO_EE_ORIGIN_ICMP6: |
| default: |
| _proto("Rx Received error report { orig=%u }", ee->ee_origin); |
| break; |
| } |
| |
| peer->error_report = err; |
| } |
| |
| /* |
| * Distribute an error that occurred on a peer |
| */ |
| void rxrpc_peer_error_distributor(struct work_struct *work) |
| { |
| struct rxrpc_peer *peer = |
| container_of(work, struct rxrpc_peer, error_distributor); |
| struct rxrpc_call *call; |
| enum rxrpc_call_completion compl; |
| int error; |
| |
| _enter(""); |
| |
| error = READ_ONCE(peer->error_report); |
| if (error < RXRPC_LOCAL_ERROR_OFFSET) { |
| compl = RXRPC_CALL_NETWORK_ERROR; |
| } else { |
| compl = RXRPC_CALL_LOCAL_ERROR; |
| error -= RXRPC_LOCAL_ERROR_OFFSET; |
| } |
| |
| _debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error); |
| |
| spin_lock_bh(&peer->lock); |
| |
| while (!hlist_empty(&peer->error_targets)) { |
| call = hlist_entry(peer->error_targets.first, |
| struct rxrpc_call, error_link); |
| hlist_del_init(&call->error_link); |
| rxrpc_see_call(call); |
| |
| if (rxrpc_set_call_completion(call, compl, 0, -error)) |
| rxrpc_notify_socket(call); |
| } |
| |
| spin_unlock_bh(&peer->lock); |
| |
| rxrpc_put_peer(peer); |
| _leave(""); |
| } |
| |
| /* |
| * Add RTT information to cache. This is called in softirq mode and has |
| * exclusive access to the peer RTT data. |
| */ |
| void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why, |
| rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial, |
| ktime_t send_time, ktime_t resp_time) |
| { |
| struct rxrpc_peer *peer = call->peer; |
| s64 rtt; |
| u64 sum = peer->rtt_sum, avg; |
| u8 cursor = peer->rtt_cursor, usage = peer->rtt_usage; |
| |
| rtt = ktime_to_ns(ktime_sub(resp_time, send_time)); |
| if (rtt < 0) |
| return; |
| |
| /* Replace the oldest datum in the RTT buffer */ |
| sum -= peer->rtt_cache[cursor]; |
| sum += rtt; |
| peer->rtt_cache[cursor] = rtt; |
| peer->rtt_cursor = (cursor + 1) & (RXRPC_RTT_CACHE_SIZE - 1); |
| peer->rtt_sum = sum; |
| if (usage < RXRPC_RTT_CACHE_SIZE) { |
| usage++; |
| peer->rtt_usage = usage; |
| } |
| |
| /* Now recalculate the average */ |
| if (usage == RXRPC_RTT_CACHE_SIZE) { |
| avg = sum / RXRPC_RTT_CACHE_SIZE; |
| } else { |
| avg = sum; |
| do_div(avg, usage); |
| } |
| |
| peer->rtt = avg; |
| trace_rxrpc_rtt_rx(call, why, send_serial, resp_serial, rtt, |
| usage, avg); |
| } |
| |
| /* |
| * Perform keep-alive pings with VERSION packets to keep any NAT alive. |
| */ |
| void rxrpc_peer_keepalive_worker(struct work_struct *work) |
| { |
| struct rxrpc_net *rxnet = |
| container_of(work, struct rxrpc_net, peer_keepalive_work); |
| struct rxrpc_peer *peer; |
| unsigned long delay; |
| ktime_t base, now = ktime_get_real(); |
| s64 diff; |
| u8 cursor, slot; |
| |
| base = rxnet->peer_keepalive_base; |
| cursor = rxnet->peer_keepalive_cursor; |
| |
| _enter("%u,%lld", cursor, ktime_sub(now, base)); |
| |
| next_bucket: |
| diff = ktime_to_ns(ktime_sub(now, base)); |
| if (diff < 0) |
| goto resched; |
| |
| _debug("at %u", cursor); |
| spin_lock_bh(&rxnet->peer_hash_lock); |
| next_peer: |
| if (!rxnet->live) { |
| spin_unlock_bh(&rxnet->peer_hash_lock); |
| goto out; |
| } |
| |
| /* Everything in the bucket at the cursor is processed this second; the |
| * bucket at cursor + 1 goes now + 1s and so on... |
| */ |
| if (hlist_empty(&rxnet->peer_keepalive[cursor])) { |
| if (hlist_empty(&rxnet->peer_keepalive_new)) { |
| spin_unlock_bh(&rxnet->peer_hash_lock); |
| goto emptied_bucket; |
| } |
| |
| hlist_move_list(&rxnet->peer_keepalive_new, |
| &rxnet->peer_keepalive[cursor]); |
| } |
| |
| peer = hlist_entry(rxnet->peer_keepalive[cursor].first, |
| struct rxrpc_peer, keepalive_link); |
| hlist_del_init(&peer->keepalive_link); |
| if (!rxrpc_get_peer_maybe(peer)) |
| goto next_peer; |
| |
| spin_unlock_bh(&rxnet->peer_hash_lock); |
| |
| _debug("peer %u {%pISp}", peer->debug_id, &peer->srx.transport); |
| |
| recalc: |
| diff = ktime_divns(ktime_sub(peer->last_tx_at, base), NSEC_PER_SEC); |
| if (diff < -30 || diff > 30) |
| goto send; /* LSW of 64-bit time probably wrapped on 32-bit */ |
| diff += RXRPC_KEEPALIVE_TIME - 1; |
| if (diff < 0) |
| goto send; |
| |
| slot = (diff > RXRPC_KEEPALIVE_TIME - 1) ? RXRPC_KEEPALIVE_TIME - 1 : diff; |
| if (slot == 0) |
| goto send; |
| |
| /* A transmission to this peer occurred since last we examined it so |
| * put it into the appropriate future bucket. |
| */ |
| slot = (slot + cursor) % ARRAY_SIZE(rxnet->peer_keepalive); |
| spin_lock_bh(&rxnet->peer_hash_lock); |
| hlist_add_head(&peer->keepalive_link, &rxnet->peer_keepalive[slot]); |
| rxrpc_put_peer(peer); |
| goto next_peer; |
| |
| send: |
| rxrpc_send_keepalive(peer); |
| now = ktime_get_real(); |
| goto recalc; |
| |
| emptied_bucket: |
| cursor++; |
| if (cursor >= ARRAY_SIZE(rxnet->peer_keepalive)) |
| cursor = 0; |
| base = ktime_add_ns(base, NSEC_PER_SEC); |
| goto next_bucket; |
| |
| resched: |
| rxnet->peer_keepalive_base = base; |
| rxnet->peer_keepalive_cursor = cursor; |
| delay = nsecs_to_jiffies(-diff) + 1; |
| timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay); |
| out: |
| _leave(""); |
| } |