1 /* Peer event handling, typically ICMP messages.
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/errqueue.h>
16 #include <linux/udp.h>
18 #include <linux/in6.h>
19 #include <linux/icmp.h>
21 #include <net/af_rxrpc.h>
23 #include "ar-internal.h"
25 static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *);
28 * Find the peer associated with an ICMP packet.
30 static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
31 const struct sk_buff *skb)
33 struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
34 struct sockaddr_rxrpc srx;
38 memset(&srx, 0, sizeof(srx));
39 srx.transport_type = local->srx.transport_type;
40 srx.transport.family = local->srx.transport.family;
42 /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice
45 switch (srx.transport.family) {
47 srx.transport.sin.sin_port = serr->port;
48 srx.transport_len = sizeof(struct sockaddr_in);
49 switch (serr->ee.ee_origin) {
50 case SO_EE_ORIGIN_ICMP:
52 memcpy(&srx.transport.sin.sin_addr,
53 skb_network_header(skb) + serr->addr_offset,
54 sizeof(struct in_addr));
56 case SO_EE_ORIGIN_ICMP6:
57 _net("Rx ICMP6 on v4 sock");
58 memcpy(&srx.transport.sin.sin_addr,
59 skb_network_header(skb) + serr->addr_offset + 12,
60 sizeof(struct in_addr));
63 memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr,
64 sizeof(struct in_addr));
73 return rxrpc_lookup_peer_rcu(local, &srx);
77 * Handle an MTU/fragmentation problem.
79 static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
81 u32 mtu = serr->ee.ee_info;
83 _net("Rx ICMP Fragmentation Needed (%d)", mtu);
85 /* wind down the local interface MTU */
86 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
88 _net("I/F MTU %u", mtu);
92 /* they didn't give us a size, estimate one */
100 if (mtu < peer->hdrsize)
101 mtu = peer->hdrsize + 4;
105 if (mtu < peer->mtu) {
106 spin_lock_bh(&peer->lock);
108 peer->maxdata = peer->mtu - peer->hdrsize;
109 spin_unlock_bh(&peer->lock);
110 _net("Net MTU %u (maxdata %u)",
111 peer->mtu, peer->maxdata);
116 * Handle an error received on the local endpoint.
118 void rxrpc_error_report(struct sock *sk)
120 struct sock_exterr_skb *serr;
121 struct rxrpc_local *local = sk->sk_user_data;
122 struct rxrpc_peer *peer;
125 _enter("%p{%d}", sk, local->debug_id);
127 skb = sock_dequeue_err_skb(sk);
129 _leave("UDP socket errqueue empty");
133 serr = SKB_EXT_ERR(skb);
134 if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
135 _leave("UDP empty message");
141 peer = rxrpc_lookup_peer_icmp_rcu(local, skb);
142 if (peer && !rxrpc_get_peer_maybe(peer))
147 _leave(" [no peer]");
151 if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
152 serr->ee.ee_type == ICMP_DEST_UNREACH &&
153 serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
154 rxrpc_adjust_mtu(peer, serr);
157 rxrpc_put_peer(peer);
158 _leave(" [MTU update]");
162 rxrpc_store_error(peer, serr);
166 /* The ref we obtained is passed off to the work item */
167 rxrpc_queue_work(&peer->error_distributor);
172 * Map an error report to error codes on the peer record.
174 static void rxrpc_store_error(struct rxrpc_peer *peer,
175 struct sock_exterr_skb *serr)
177 struct sock_extended_err *ee;
184 _net("Rx Error o=%d t=%d c=%d e=%d",
185 ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
189 switch (ee->ee_origin) {
190 case SO_EE_ORIGIN_ICMP:
191 switch (ee->ee_type) {
192 case ICMP_DEST_UNREACH:
193 switch (ee->ee_code) {
194 case ICMP_NET_UNREACH:
195 _net("Rx Received ICMP Network Unreachable");
197 case ICMP_HOST_UNREACH:
198 _net("Rx Received ICMP Host Unreachable");
200 case ICMP_PORT_UNREACH:
201 _net("Rx Received ICMP Port Unreachable");
203 case ICMP_NET_UNKNOWN:
204 _net("Rx Received ICMP Unknown Network");
206 case ICMP_HOST_UNKNOWN:
207 _net("Rx Received ICMP Unknown Host");
210 _net("Rx Received ICMP DestUnreach code=%u",
216 case ICMP_TIME_EXCEEDED:
217 _net("Rx Received ICMP TTL Exceeded");
221 _proto("Rx Received ICMP error { type=%u code=%u }",
222 ee->ee_type, ee->ee_code);
227 case SO_EE_ORIGIN_NONE:
228 case SO_EE_ORIGIN_LOCAL:
229 _proto("Rx Received local error { error=%d }", err);
230 err += RXRPC_LOCAL_ERROR_OFFSET;
233 case SO_EE_ORIGIN_ICMP6:
235 _proto("Rx Received error report { orig=%u }", ee->ee_origin);
239 peer->error_report = err;
243 * Distribute an error that occurred on a peer
245 void rxrpc_peer_error_distributor(struct work_struct *work)
247 struct rxrpc_peer *peer =
248 container_of(work, struct rxrpc_peer, error_distributor);
249 struct rxrpc_call *call;
250 enum rxrpc_call_completion compl;
255 error = READ_ONCE(peer->error_report);
256 if (error < RXRPC_LOCAL_ERROR_OFFSET) {
257 compl = RXRPC_CALL_NETWORK_ERROR;
259 compl = RXRPC_CALL_LOCAL_ERROR;
260 error -= RXRPC_LOCAL_ERROR_OFFSET;
263 _debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error);
265 spin_lock_bh(&peer->lock);
267 while (!hlist_empty(&peer->error_targets)) {
268 call = hlist_entry(peer->error_targets.first,
269 struct rxrpc_call, error_link);
270 hlist_del_init(&call->error_link);
271 rxrpc_see_call(call);
273 if (rxrpc_set_call_completion(call, compl, 0, error))
274 rxrpc_notify_socket(call);
277 spin_unlock_bh(&peer->lock);
279 rxrpc_put_peer(peer);