Merge tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof...
[firefly-linux-kernel-4.4.55.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 = sock_dequeue_err_skb(sk);
41         if (!skb) {
42                 _leave("UDP socket errqueue empty");
43                 return;
44         }
45         serr = SKB_EXT_ERR(skb);
46         if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
47                 _leave("UDP empty message");
48                 kfree_skb(skb);
49                 return;
50         }
51
52         rxrpc_new_skb(skb);
53
54         addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset);
55         port = serr->port;
56
57         _net("Rx UDP Error from %pI4:%hu", &addr, ntohs(port));
58         _debug("Msg l:%d d:%d", skb->len, skb->data_len);
59
60         peer = rxrpc_find_peer(local, addr, port);
61         if (IS_ERR(peer)) {
62                 rxrpc_free_skb(skb);
63                 _leave(" [no peer]");
64                 return;
65         }
66
67         trans = rxrpc_find_transport(local, peer);
68         if (!trans) {
69                 rxrpc_put_peer(peer);
70                 rxrpc_free_skb(skb);
71                 _leave(" [no trans]");
72                 return;
73         }
74
75         if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
76             serr->ee.ee_type == ICMP_DEST_UNREACH &&
77             serr->ee.ee_code == ICMP_FRAG_NEEDED
78             ) {
79                 u32 mtu = serr->ee.ee_info;
80
81                 _net("Rx Received ICMP Fragmentation Needed (%d)", mtu);
82
83                 /* wind down the local interface MTU */
84                 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
85                         peer->if_mtu = mtu;
86                         _net("I/F MTU %u", mtu);
87                 }
88
89                 if (mtu == 0) {
90                         /* they didn't give us a size, estimate one */
91                         mtu = peer->if_mtu;
92                         if (mtu > 1500) {
93                                 mtu >>= 1;
94                                 if (mtu < 1500)
95                                         mtu = 1500;
96                         } else {
97                                 mtu -= 100;
98                                 if (mtu < peer->hdrsize)
99                                         mtu = peer->hdrsize + 4;
100                         }
101                 }
102
103                 if (mtu < peer->mtu) {
104                         spin_lock_bh(&peer->lock);
105                         peer->mtu = mtu;
106                         peer->maxdata = peer->mtu - peer->hdrsize;
107                         spin_unlock_bh(&peer->lock);
108                         _net("Net MTU %u (maxdata %u)",
109                              peer->mtu, peer->maxdata);
110                 }
111         }
112
113         rxrpc_put_peer(peer);
114
115         /* pass the transport ref to error_handler to release */
116         skb_queue_tail(&trans->error_queue, skb);
117         rxrpc_queue_work(&trans->error_handler);
118
119         _leave("");
120 }
121
122 /*
123  * deal with UDP error messages
124  */
125 void rxrpc_UDP_error_handler(struct work_struct *work)
126 {
127         struct sock_extended_err *ee;
128         struct sock_exterr_skb *serr;
129         struct rxrpc_transport *trans =
130                 container_of(work, struct rxrpc_transport, error_handler);
131         struct sk_buff *skb;
132         int err;
133
134         _enter("");
135
136         skb = skb_dequeue(&trans->error_queue);
137         if (!skb)
138                 return;
139
140         serr = SKB_EXT_ERR(skb);
141         ee = &serr->ee;
142
143         _net("Rx Error o=%d t=%d c=%d e=%d",
144              ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
145
146         err = ee->ee_errno;
147
148         switch (ee->ee_origin) {
149         case SO_EE_ORIGIN_ICMP:
150                 switch (ee->ee_type) {
151                 case ICMP_DEST_UNREACH:
152                         switch (ee->ee_code) {
153                         case ICMP_NET_UNREACH:
154                                 _net("Rx Received ICMP Network Unreachable");
155                                 err = ENETUNREACH;
156                                 break;
157                         case ICMP_HOST_UNREACH:
158                                 _net("Rx Received ICMP Host Unreachable");
159                                 err = EHOSTUNREACH;
160                                 break;
161                         case ICMP_PORT_UNREACH:
162                                 _net("Rx Received ICMP Port Unreachable");
163                                 err = ECONNREFUSED;
164                                 break;
165                         case ICMP_FRAG_NEEDED:
166                                 _net("Rx Received ICMP Fragmentation Needed (%d)",
167                                      ee->ee_info);
168                                 err = 0; /* dealt with elsewhere */
169                                 break;
170                         case ICMP_NET_UNKNOWN:
171                                 _net("Rx Received ICMP Unknown Network");
172                                 err = ENETUNREACH;
173                                 break;
174                         case ICMP_HOST_UNKNOWN:
175                                 _net("Rx Received ICMP Unknown Host");
176                                 err = EHOSTUNREACH;
177                                 break;
178                         default:
179                                 _net("Rx Received ICMP DestUnreach code=%u",
180                                      ee->ee_code);
181                                 break;
182                         }
183                         break;
184
185                 case ICMP_TIME_EXCEEDED:
186                         _net("Rx Received ICMP TTL Exceeded");
187                         break;
188
189                 default:
190                         _proto("Rx Received ICMP error { type=%u code=%u }",
191                                ee->ee_type, ee->ee_code);
192                         break;
193                 }
194                 break;
195
196         case SO_EE_ORIGIN_LOCAL:
197                 _proto("Rx Received local error { error=%d }",
198                        ee->ee_errno);
199                 break;
200
201         case SO_EE_ORIGIN_NONE:
202         case SO_EE_ORIGIN_ICMP6:
203         default:
204                 _proto("Rx Received error report { orig=%u }",
205                        ee->ee_origin);
206                 break;
207         }
208
209         /* terminate all the affected calls if there's an unrecoverable
210          * error */
211         if (err) {
212                 struct rxrpc_call *call, *_n;
213
214                 _debug("ISSUE ERROR %d", err);
215
216                 spin_lock_bh(&trans->peer->lock);
217                 trans->peer->net_error = err;
218
219                 list_for_each_entry_safe(call, _n, &trans->peer->error_targets,
220                                          error_link) {
221                         write_lock(&call->state_lock);
222                         if (call->state != RXRPC_CALL_COMPLETE &&
223                             call->state < RXRPC_CALL_NETWORK_ERROR) {
224                                 call->state = RXRPC_CALL_NETWORK_ERROR;
225                                 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
226                                 rxrpc_queue_call(call);
227                         }
228                         write_unlock(&call->state_lock);
229                         list_del_init(&call->error_link);
230                 }
231
232                 spin_unlock_bh(&trans->peer->lock);
233         }
234
235         if (!skb_queue_empty(&trans->error_queue))
236                 rxrpc_queue_work(&trans->error_handler);
237
238         rxrpc_free_skb(skb);
239         rxrpc_put_transport(trans);
240         _leave("");
241 }