[AF_RXRPC]: Add an interface to the AF_RXRPC module for the AFS filesystem to use
[linux-3.10.git] / 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                         peer->mtu = mtu;
104                         peer->maxdata = peer->mtu - peer->hdrsize;
105                         _net("Net MTU %u (maxdata %u)",
106                              peer->mtu, peer->maxdata);
107                 }
108         }
109
110         rxrpc_put_peer(peer);
111
112         /* pass the transport ref to error_handler to release */
113         skb_queue_tail(&trans->error_queue, skb);
114         rxrpc_queue_work(&trans->error_handler);
115
116         /* reset and regenerate socket error */
117         spin_lock_bh(&sk->sk_error_queue.lock);
118         sk->sk_err = 0;
119         skb = skb_peek(&sk->sk_error_queue);
120         if (skb) {
121                 sk->sk_err = SKB_EXT_ERR(skb)->ee.ee_errno;
122                 spin_unlock_bh(&sk->sk_error_queue.lock);
123                 sk->sk_error_report(sk);
124         } else {
125                 spin_unlock_bh(&sk->sk_error_queue.lock);
126         }
127
128         _leave("");
129 }
130
131 /*
132  * deal with UDP error messages
133  */
134 void rxrpc_UDP_error_handler(struct work_struct *work)
135 {
136         struct sock_extended_err *ee;
137         struct sock_exterr_skb *serr;
138         struct rxrpc_transport *trans =
139                 container_of(work, struct rxrpc_transport, error_handler);
140         struct sk_buff *skb;
141         int local, err;
142
143         _enter("");
144
145         skb = skb_dequeue(&trans->error_queue);
146         if (!skb)
147                 return;
148
149         serr = SKB_EXT_ERR(skb);
150         ee = &serr->ee;
151
152         _net("Rx Error o=%d t=%d c=%d e=%d",
153              ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
154
155         err = ee->ee_errno;
156
157         switch (ee->ee_origin) {
158         case SO_EE_ORIGIN_ICMP:
159                 local = 0;
160                 switch (ee->ee_type) {
161                 case ICMP_DEST_UNREACH:
162                         switch (ee->ee_code) {
163                         case ICMP_NET_UNREACH:
164                                 _net("Rx Received ICMP Network Unreachable");
165                                 err = ENETUNREACH;
166                                 break;
167                         case ICMP_HOST_UNREACH:
168                                 _net("Rx Received ICMP Host Unreachable");
169                                 err = EHOSTUNREACH;
170                                 break;
171                         case ICMP_PORT_UNREACH:
172                                 _net("Rx Received ICMP Port Unreachable");
173                                 err = ECONNREFUSED;
174                                 break;
175                         case ICMP_FRAG_NEEDED:
176                                 _net("Rx Received ICMP Fragmentation Needed (%d)",
177                                      ee->ee_info);
178                                 err = 0; /* dealt with elsewhere */
179                                 break;
180                         case ICMP_NET_UNKNOWN:
181                                 _net("Rx Received ICMP Unknown Network");
182                                 err = ENETUNREACH;
183                                 break;
184                         case ICMP_HOST_UNKNOWN:
185                                 _net("Rx Received ICMP Unknown Host");
186                                 err = EHOSTUNREACH;
187                                 break;
188                         default:
189                                 _net("Rx Received ICMP DestUnreach code=%u",
190                                      ee->ee_code);
191                                 break;
192                         }
193                         break;
194
195                 case ICMP_TIME_EXCEEDED:
196                         _net("Rx Received ICMP TTL Exceeded");
197                         break;
198
199                 default:
200                         _proto("Rx Received ICMP error { type=%u code=%u }",
201                                ee->ee_type, ee->ee_code);
202                         break;
203                 }
204                 break;
205
206         case SO_EE_ORIGIN_LOCAL:
207                 _proto("Rx Received local error { error=%d }",
208                        ee->ee_errno);
209                 local = 1;
210                 break;
211
212         case SO_EE_ORIGIN_NONE:
213         case SO_EE_ORIGIN_ICMP6:
214         default:
215                 _proto("Rx Received error report { orig=%u }",
216                        ee->ee_origin);
217                 local = 0;
218                 break;
219         }
220
221         /* terminate all the affected calls if there's an unrecoverable
222          * error */
223         if (err) {
224                 struct rxrpc_call *call, *_n;
225
226                 _debug("ISSUE ERROR %d", err);
227
228                 spin_lock_bh(&trans->peer->lock);
229                 trans->peer->net_error = err;
230
231                 list_for_each_entry_safe(call, _n, &trans->peer->error_targets,
232                                          error_link) {
233                         write_lock(&call->state_lock);
234                         if (call->state != RXRPC_CALL_COMPLETE &&
235                             call->state < RXRPC_CALL_NETWORK_ERROR) {
236                                 call->state = RXRPC_CALL_NETWORK_ERROR;
237                                 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
238                                 rxrpc_queue_call(call);
239                         }
240                         write_unlock(&call->state_lock);
241                         list_del_init(&call->error_link);
242                 }
243
244                 spin_unlock_bh(&trans->peer->lock);
245         }
246
247         if (!skb_queue_empty(&trans->error_queue))
248                 rxrpc_queue_work(&trans->error_handler);
249
250         rxrpc_free_skb(skb);
251         rxrpc_put_transport(trans);
252         _leave("");
253 }