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f66d7490 | 1 | /* Peer event handling, typically ICMP messages. |
17926a79 DH |
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 | ||
f66d7490 DH |
25 | static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *); |
26 | ||
be6e6707 DH |
27 | /* |
28 | * Find the peer associated with an ICMP packet. | |
29 | */ | |
30 | static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local, | |
31 | const struct sk_buff *skb) | |
32 | { | |
33 | struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); | |
34 | struct sockaddr_rxrpc srx; | |
35 | ||
36 | _enter(""); | |
37 | ||
38 | memset(&srx, 0, sizeof(srx)); | |
39 | srx.transport_type = local->srx.transport_type; | |
40 | srx.transport.family = local->srx.transport.family; | |
41 | ||
42 | /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice | |
43 | * versa? | |
44 | */ | |
45 | switch (srx.transport.family) { | |
46 | case AF_INET: | |
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: | |
51 | _net("Rx ICMP"); | |
52 | memcpy(&srx.transport.sin.sin_addr, | |
53 | skb_network_header(skb) + serr->addr_offset, | |
54 | sizeof(struct in_addr)); | |
55 | break; | |
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)); | |
61 | break; | |
62 | default: | |
63 | memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr, | |
64 | sizeof(struct in_addr)); | |
65 | break; | |
66 | } | |
67 | break; | |
68 | ||
69 | default: | |
70 | BUG(); | |
71 | } | |
72 | ||
73 | return rxrpc_lookup_peer_rcu(local, &srx); | |
74 | } | |
75 | ||
1a70c05b DH |
76 | /* |
77 | * Handle an MTU/fragmentation problem. | |
78 | */ | |
79 | static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr) | |
80 | { | |
81 | u32 mtu = serr->ee.ee_info; | |
82 | ||
83 | _net("Rx ICMP Fragmentation Needed (%d)", mtu); | |
84 | ||
85 | /* wind down the local interface MTU */ | |
86 | if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { | |
87 | peer->if_mtu = mtu; | |
88 | _net("I/F MTU %u", mtu); | |
89 | } | |
90 | ||
91 | if (mtu == 0) { | |
92 | /* they didn't give us a size, estimate one */ | |
93 | mtu = peer->if_mtu; | |
94 | if (mtu > 1500) { | |
95 | mtu >>= 1; | |
96 | if (mtu < 1500) | |
97 | mtu = 1500; | |
98 | } else { | |
99 | mtu -= 100; | |
100 | if (mtu < peer->hdrsize) | |
101 | mtu = peer->hdrsize + 4; | |
102 | } | |
103 | } | |
104 | ||
105 | if (mtu < peer->mtu) { | |
106 | spin_lock_bh(&peer->lock); | |
107 | peer->mtu = mtu; | |
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); | |
112 | } | |
113 | } | |
114 | ||
17926a79 | 115 | /* |
f66d7490 | 116 | * Handle an error received on the local endpoint. |
17926a79 | 117 | */ |
abe89ef0 | 118 | void rxrpc_error_report(struct sock *sk) |
17926a79 DH |
119 | { |
120 | struct sock_exterr_skb *serr; | |
17926a79 DH |
121 | struct rxrpc_local *local = sk->sk_user_data; |
122 | struct rxrpc_peer *peer; | |
123 | struct sk_buff *skb; | |
17926a79 DH |
124 | |
125 | _enter("%p{%d}", sk, local->debug_id); | |
126 | ||
364a9e93 | 127 | skb = sock_dequeue_err_skb(sk); |
17926a79 DH |
128 | if (!skb) { |
129 | _leave("UDP socket errqueue empty"); | |
130 | return; | |
131 | } | |
c247f053 WB |
132 | serr = SKB_EXT_ERR(skb); |
133 | if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { | |
49ca0d8b WB |
134 | _leave("UDP empty message"); |
135 | kfree_skb(skb); | |
136 | return; | |
137 | } | |
17926a79 DH |
138 | |
139 | rxrpc_new_skb(skb); | |
140 | ||
be6e6707 DH |
141 | rcu_read_lock(); |
142 | peer = rxrpc_lookup_peer_icmp_rcu(local, skb); | |
143 | if (peer && !rxrpc_get_peer_maybe(peer)) | |
144 | peer = NULL; | |
145 | if (!peer) { | |
146 | rcu_read_unlock(); | |
17926a79 DH |
147 | rxrpc_free_skb(skb); |
148 | _leave(" [no peer]"); | |
149 | return; | |
150 | } | |
151 | ||
1a70c05b DH |
152 | if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && |
153 | serr->ee.ee_type == ICMP_DEST_UNREACH && | |
154 | serr->ee.ee_code == ICMP_FRAG_NEEDED)) { | |
155 | rxrpc_adjust_mtu(peer, serr); | |
f66d7490 | 156 | rcu_read_unlock(); |
1a70c05b | 157 | rxrpc_free_skb(skb); |
f66d7490 DH |
158 | rxrpc_put_peer(peer); |
159 | _leave(" [MTU update]"); | |
160 | return; | |
17926a79 DH |
161 | } |
162 | ||
f66d7490 | 163 | rxrpc_store_error(peer, serr); |
be6e6707 | 164 | rcu_read_unlock(); |
f66d7490 | 165 | rxrpc_free_skb(skb); |
17926a79 | 166 | |
f66d7490 DH |
167 | /* The ref we obtained is passed off to the work item */ |
168 | rxrpc_queue_work(&peer->error_distributor); | |
17926a79 DH |
169 | _leave(""); |
170 | } | |
171 | ||
172 | /* | |
f66d7490 | 173 | * Map an error report to error codes on the peer record. |
17926a79 | 174 | */ |
f66d7490 DH |
175 | static void rxrpc_store_error(struct rxrpc_peer *peer, |
176 | struct sock_exterr_skb *serr) | |
17926a79 DH |
177 | { |
178 | struct sock_extended_err *ee; | |
c9d10c49 | 179 | int err; |
17926a79 DH |
180 | |
181 | _enter(""); | |
182 | ||
17926a79 DH |
183 | ee = &serr->ee; |
184 | ||
185 | _net("Rx Error o=%d t=%d c=%d e=%d", | |
186 | ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno); | |
187 | ||
188 | err = ee->ee_errno; | |
189 | ||
190 | switch (ee->ee_origin) { | |
191 | case SO_EE_ORIGIN_ICMP: | |
17926a79 DH |
192 | switch (ee->ee_type) { |
193 | case ICMP_DEST_UNREACH: | |
194 | switch (ee->ee_code) { | |
195 | case ICMP_NET_UNREACH: | |
196 | _net("Rx Received ICMP Network Unreachable"); | |
17926a79 DH |
197 | break; |
198 | case ICMP_HOST_UNREACH: | |
199 | _net("Rx Received ICMP Host Unreachable"); | |
17926a79 DH |
200 | break; |
201 | case ICMP_PORT_UNREACH: | |
202 | _net("Rx Received ICMP Port Unreachable"); | |
17926a79 DH |
203 | break; |
204 | case ICMP_NET_UNKNOWN: | |
205 | _net("Rx Received ICMP Unknown Network"); | |
17926a79 DH |
206 | break; |
207 | case ICMP_HOST_UNKNOWN: | |
208 | _net("Rx Received ICMP Unknown Host"); | |
17926a79 DH |
209 | break; |
210 | default: | |
211 | _net("Rx Received ICMP DestUnreach code=%u", | |
212 | ee->ee_code); | |
213 | break; | |
214 | } | |
215 | break; | |
216 | ||
217 | case ICMP_TIME_EXCEEDED: | |
218 | _net("Rx Received ICMP TTL Exceeded"); | |
219 | break; | |
220 | ||
221 | default: | |
222 | _proto("Rx Received ICMP error { type=%u code=%u }", | |
223 | ee->ee_type, ee->ee_code); | |
224 | break; | |
225 | } | |
226 | break; | |
227 | ||
f66d7490 | 228 | case SO_EE_ORIGIN_NONE: |
17926a79 | 229 | case SO_EE_ORIGIN_LOCAL: |
fe77d5fc | 230 | _proto("Rx Received local error { error=%d }", err); |
f66d7490 | 231 | err += RXRPC_LOCAL_ERROR_OFFSET; |
17926a79 DH |
232 | break; |
233 | ||
17926a79 DH |
234 | case SO_EE_ORIGIN_ICMP6: |
235 | default: | |
fe77d5fc | 236 | _proto("Rx Received error report { orig=%u }", ee->ee_origin); |
17926a79 DH |
237 | break; |
238 | } | |
239 | ||
f66d7490 DH |
240 | peer->error_report = err; |
241 | } | |
242 | ||
243 | /* | |
244 | * Distribute an error that occurred on a peer | |
245 | */ | |
246 | void rxrpc_peer_error_distributor(struct work_struct *work) | |
247 | { | |
248 | struct rxrpc_peer *peer = | |
249 | container_of(work, struct rxrpc_peer, error_distributor); | |
250 | struct rxrpc_call *call; | |
251 | int error_report; | |
252 | ||
253 | _enter(""); | |
17926a79 | 254 | |
f66d7490 | 255 | error_report = READ_ONCE(peer->error_report); |
17926a79 | 256 | |
f66d7490 | 257 | _debug("ISSUE ERROR %d", error_report); |
17926a79 | 258 | |
f66d7490 | 259 | spin_lock_bh(&peer->lock); |
17926a79 | 260 | |
f66d7490 DH |
261 | while (!hlist_empty(&peer->error_targets)) { |
262 | call = hlist_entry(peer->error_targets.first, | |
263 | struct rxrpc_call, error_link); | |
264 | hlist_del_init(&call->error_link); | |
265 | ||
266 | write_lock(&call->state_lock); | |
267 | if (call->state != RXRPC_CALL_COMPLETE && | |
268 | call->state < RXRPC_CALL_NETWORK_ERROR) { | |
269 | call->error_report = error_report; | |
270 | call->state = RXRPC_CALL_NETWORK_ERROR; | |
271 | set_bit(RXRPC_CALL_EV_RCVD_ERROR, &call->events); | |
272 | rxrpc_queue_call(call); | |
273 | } | |
274 | write_unlock(&call->state_lock); | |
17926a79 DH |
275 | } |
276 | ||
f66d7490 | 277 | spin_unlock_bh(&peer->lock); |
17926a79 | 278 | |
f66d7490 | 279 | rxrpc_put_peer(peer); |
17926a79 DH |
280 | _leave(""); |
281 | } |