1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
|
/* 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.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;
srx.transport_len = sizeof(struct sockaddr_in);
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;
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;
}
serr = SKB_EXT_ERR(skb);
if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
_leave("UDP empty message");
kfree_skb(skb);
return;
}
rxrpc_new_skb(skb);
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);
_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_put_peer(peer);
_leave(" [MTU update]");
return;
}
rxrpc_store_error(peer, serr);
rcu_read_unlock();
rxrpc_free_skb(skb);
/* The ref we obtained is passed off to the work item */
rxrpc_queue_work(&peer->error_distributor);
_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;
int error_report;
_enter("");
error_report = READ_ONCE(peer->error_report);
_debug("ISSUE ERROR %d", error_report);
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);
write_lock(&call->state_lock);
if (call->state != RXRPC_CALL_COMPLETE &&
call->state < RXRPC_CALL_NETWORK_ERROR) {
call->error_report = error_report;
call->state = RXRPC_CALL_NETWORK_ERROR;
set_bit(RXRPC_CALL_EV_RCVD_ERROR, &call->events);
rxrpc_queue_call(call);
}
write_unlock(&call->state_lock);
}
spin_unlock_bh(&peer->lock);
rxrpc_put_peer(peer);
_leave("");
}
|
