Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/voyager-2.6
[linux-2.6] / net / rxrpc / ar-error.c
1 /* Error message handling (ICMP)
2  *
3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
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.
10  */
11
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>
17 #include <linux/in.h>
18 #include <linux/in6.h>
19 #include <linux/icmp.h>
20 #include <net/sock.h>
21 #include <net/af_rxrpc.h>
22 #include <net/ip.h>
23 #include "ar-internal.h"
24
25 /*
26  * handle an error received on the local endpoint
27  */
28 void rxrpc_UDP_error_report(struct sock *sk)
29 {
30         struct sock_exterr_skb *serr;
31         struct rxrpc_transport *trans;
32         struct rxrpc_local *local = sk->sk_user_data;
33         struct rxrpc_peer *peer;
34         struct sk_buff *skb;
35         __be32 addr;
36         __be16 port;
37
38         _enter("%p{%d}", sk, local->debug_id);
39
40         skb = skb_dequeue(&sk->sk_error_queue);
41         if (!skb) {
42                 _leave("UDP socket errqueue empty");
43                 return;
44         }
45
46         rxrpc_new_skb(skb);
47
48         serr = SKB_EXT_ERR(skb);
49         addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset);
50         port = serr->port;
51
52         _net("Rx UDP Error from "NIPQUAD_FMT":%hu",
53              NIPQUAD(addr), ntohs(port));
54         _debug("Msg l:%d d:%d", skb->len, skb->data_len);
55
56         peer = rxrpc_find_peer(local, addr, port);
57         if (IS_ERR(peer)) {
58                 rxrpc_free_skb(skb);
59                 _leave(" [no peer]");
60                 return;
61         }
62
63         trans = rxrpc_find_transport(local, peer);
64         if (!trans) {
65                 rxrpc_put_peer(peer);
66                 rxrpc_free_skb(skb);
67                 _leave(" [no trans]");
68                 return;
69         }
70
71         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
72             serr->ee.ee_type == ICMP_DEST_UNREACH &&
73             serr->ee.ee_code == ICMP_FRAG_NEEDED
74             ) {
75                 u32 mtu = serr->ee.ee_info;
76
77                 _net("Rx Received ICMP Fragmentation Needed (%d)", mtu);
78
79                 /* wind down the local interface MTU */
80                 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
81                         peer->if_mtu = mtu;
82                         _net("I/F MTU %u", mtu);
83                 }
84
85                 /* ip_rt_frag_needed() may have eaten the info */
86                 if (mtu == 0)
87                         mtu = ntohs(icmp_hdr(skb)->un.frag.mtu);
88
89                 if (mtu == 0) {
90                         /* they didn't give us a size, estimate one */
91                         if (mtu > 1500) {
92                                 mtu >>= 1;
93                                 if (mtu < 1500)
94                                         mtu = 1500;
95                         } else {
96                                 mtu -= 100;
97                                 if (mtu < peer->hdrsize)
98                                         mtu = peer->hdrsize + 4;
99                         }
100                 }
101
102                 if (mtu < peer->mtu) {
103                         spin_lock_bh(&peer->lock);
104                         peer->mtu = mtu;
105                         peer->maxdata = peer->mtu - peer->hdrsize;
106                         spin_unlock_bh(&peer->lock);
107                         _net("Net MTU %u (maxdata %u)",
108                              peer->mtu, peer->maxdata);
109                 }
110         }
111
112         rxrpc_put_peer(peer);
113
114         /* pass the transport ref to error_handler to release */
115         skb_queue_tail(&trans->error_queue, skb);
116         rxrpc_queue_work(&trans->error_handler);
117
118         /* reset and regenerate socket error */
119         spin_lock_bh(&sk->sk_error_queue.lock);
120         sk->sk_err = 0;
121         skb = skb_peek(&sk->sk_error_queue);
122         if (skb) {
123                 sk->sk_err = SKB_EXT_ERR(skb)->ee.ee_errno;
124                 spin_unlock_bh(&sk->sk_error_queue.lock);
125                 sk->sk_error_report(sk);
126         } else {
127                 spin_unlock_bh(&sk->sk_error_queue.lock);
128         }
129
130         _leave("");
131 }
132
133 /*
134  * deal with UDP error messages
135  */
136 void rxrpc_UDP_error_handler(struct work_struct *work)
137 {
138         struct sock_extended_err *ee;
139         struct sock_exterr_skb *serr;
140         struct rxrpc_transport *trans =
141                 container_of(work, struct rxrpc_transport, error_handler);
142         struct sk_buff *skb;
143         int local, err;
144
145         _enter("");
146
147         skb = skb_dequeue(&trans->error_queue);
148         if (!skb)
149                 return;
150
151         serr = SKB_EXT_ERR(skb);
152         ee = &serr->ee;
153
154         _net("Rx Error o=%d t=%d c=%d e=%d",
155              ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
156
157         err = ee->ee_errno;
158
159         switch (ee->ee_origin) {
160         case SO_EE_ORIGIN_ICMP:
161                 local = 0;
162                 switch (ee->ee_type) {
163                 case ICMP_DEST_UNREACH:
164                         switch (ee->ee_code) {
165                         case ICMP_NET_UNREACH:
166                                 _net("Rx Received ICMP Network Unreachable");
167                                 err = ENETUNREACH;
168                                 break;
169                         case ICMP_HOST_UNREACH:
170                                 _net("Rx Received ICMP Host Unreachable");
171                                 err = EHOSTUNREACH;
172                                 break;
173                         case ICMP_PORT_UNREACH:
174                                 _net("Rx Received ICMP Port Unreachable");
175                                 err = ECONNREFUSED;
176                                 break;
177                         case ICMP_FRAG_NEEDED:
178                                 _net("Rx Received ICMP Fragmentation Needed (%d)",
179                                      ee->ee_info);
180                                 err = 0; /* dealt with elsewhere */
181                                 break;
182                         case ICMP_NET_UNKNOWN:
183                                 _net("Rx Received ICMP Unknown Network");
184                                 err = ENETUNREACH;
185                                 break;
186                         case ICMP_HOST_UNKNOWN:
187                                 _net("Rx Received ICMP Unknown Host");
188                                 err = EHOSTUNREACH;
189                                 break;
190                         default:
191                                 _net("Rx Received ICMP DestUnreach code=%u",
192                                      ee->ee_code);
193                                 break;
194                         }
195                         break;
196
197                 case ICMP_TIME_EXCEEDED:
198                         _net("Rx Received ICMP TTL Exceeded");
199                         break;
200
201                 default:
202                         _proto("Rx Received ICMP error { type=%u code=%u }",
203                                ee->ee_type, ee->ee_code);
204                         break;
205                 }
206                 break;
207
208         case SO_EE_ORIGIN_LOCAL:
209                 _proto("Rx Received local error { error=%d }",
210                        ee->ee_errno);
211                 local = 1;
212                 break;
213
214         case SO_EE_ORIGIN_NONE:
215         case SO_EE_ORIGIN_ICMP6:
216         default:
217                 _proto("Rx Received error report { orig=%u }",
218                        ee->ee_origin);
219                 local = 0;
220                 break;
221         }
222
223         /* terminate all the affected calls if there's an unrecoverable
224          * error */
225         if (err) {
226                 struct rxrpc_call *call, *_n;
227
228                 _debug("ISSUE ERROR %d", err);
229
230                 spin_lock_bh(&trans->peer->lock);
231                 trans->peer->net_error = err;
232
233                 list_for_each_entry_safe(call, _n, &trans->peer->error_targets,
234                                          error_link) {
235                         write_lock(&call->state_lock);
236                         if (call->state != RXRPC_CALL_COMPLETE &&
237                             call->state < RXRPC_CALL_NETWORK_ERROR) {
238                                 call->state = RXRPC_CALL_NETWORK_ERROR;
239                                 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
240                                 rxrpc_queue_call(call);
241                         }
242                         write_unlock(&call->state_lock);
243                         list_del_init(&call->error_link);
244                 }
245
246                 spin_unlock_bh(&trans->peer->lock);
247         }
248
249         if (!skb_queue_empty(&trans->error_queue))
250                 rxrpc_queue_work(&trans->error_handler);
251
252         rxrpc_free_skb(skb);
253         rxrpc_put_transport(trans);
254         _leave("");
255 }