Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * NET3: Implementation of the ICMP protocol layer. | |
4 | * | |
113aa838 | 5 | * Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 6 | * |
1da177e4 LT |
7 | * Some of the function names and the icmp unreach table for this |
8 | * module were derived from [icmp.c 1.0.11 06/02/93] by | |
9 | * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting. | |
10 | * Other than that this module is a complete rewrite. | |
11 | * | |
12 | * Fixes: | |
13 | * Clemens Fruhwirth : introduce global icmp rate limiting | |
14 | * with icmp type masking ability instead | |
15 | * of broken per type icmp timeouts. | |
16 | * Mike Shaver : RFC1122 checks. | |
17 | * Alan Cox : Multicast ping reply as self. | |
18 | * Alan Cox : Fix atomicity lockup in ip_build_xmit | |
19 | * call. | |
20 | * Alan Cox : Added 216,128 byte paths to the MTU | |
21 | * code. | |
22 | * Martin Mares : RFC1812 checks. | |
23 | * Martin Mares : Can be configured to follow redirects | |
24 | * if acting as a router _without_ a | |
25 | * routing protocol (RFC 1812). | |
26 | * Martin Mares : Echo requests may be configured to | |
27 | * be ignored (RFC 1812). | |
28 | * Martin Mares : Limitation of ICMP error message | |
29 | * transmit rate (RFC 1812). | |
30 | * Martin Mares : TOS and Precedence set correctly | |
31 | * (RFC 1812). | |
32 | * Martin Mares : Now copying as much data from the | |
33 | * original packet as we can without | |
34 | * exceeding 576 bytes (RFC 1812). | |
35 | * Willy Konynenberg : Transparent proxying support. | |
36 | * Keith Owens : RFC1191 correction for 4.2BSD based | |
37 | * path MTU bug. | |
38 | * Thomas Quinot : ICMP Dest Unreach codes up to 15 are | |
39 | * valid (RFC 1812). | |
40 | * Andi Kleen : Check all packet lengths properly | |
41 | * and moved all kfree_skb() up to | |
42 | * icmp_rcv. | |
43 | * Andi Kleen : Move the rate limit bookkeeping | |
44 | * into the dest entry and use a token | |
45 | * bucket filter (thanks to ANK). Make | |
46 | * the rates sysctl configurable. | |
47 | * Yu Tianli : Fixed two ugly bugs in icmp_send | |
48 | * - IP option length was accounted wrongly | |
49 | * - ICMP header length was not accounted | |
50 | * at all. | |
51 | * Tristan Greaves : Added sysctl option to ignore bogus | |
52 | * broadcast responses from broken routers. | |
53 | * | |
54 | * To Fix: | |
55 | * | |
56 | * - Should use skb_pull() instead of all the manual checking. | |
57 | * This would also greatly simply some upper layer error handlers. --AK | |
1da177e4 LT |
58 | */ |
59 | ||
afd46503 JP |
60 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
61 | ||
1da177e4 LT |
62 | #include <linux/module.h> |
63 | #include <linux/types.h> | |
64 | #include <linux/jiffies.h> | |
65 | #include <linux/kernel.h> | |
66 | #include <linux/fcntl.h> | |
67 | #include <linux/socket.h> | |
68 | #include <linux/in.h> | |
69 | #include <linux/inet.h> | |
14c85021 | 70 | #include <linux/inetdevice.h> |
1da177e4 LT |
71 | #include <linux/netdevice.h> |
72 | #include <linux/string.h> | |
73 | #include <linux/netfilter_ipv4.h> | |
5a0e3ad6 | 74 | #include <linux/slab.h> |
1da177e4 LT |
75 | #include <net/snmp.h> |
76 | #include <net/ip.h> | |
77 | #include <net/route.h> | |
78 | #include <net/protocol.h> | |
79 | #include <net/icmp.h> | |
80 | #include <net/tcp.h> | |
81 | #include <net/udp.h> | |
82 | #include <net/raw.h> | |
c319b4d7 | 83 | #include <net/ping.h> |
1da177e4 LT |
84 | #include <linux/skbuff.h> |
85 | #include <net/sock.h> | |
86 | #include <linux/errno.h> | |
87 | #include <linux/timer.h> | |
88 | #include <linux/init.h> | |
7c0f6ba6 | 89 | #include <linux/uaccess.h> |
1da177e4 | 90 | #include <net/checksum.h> |
8b7817f3 | 91 | #include <net/xfrm.h> |
c1e9894d | 92 | #include <net/inet_common.h> |
35ebf65e | 93 | #include <net/ip_fib.h> |
385add90 | 94 | #include <net/l3mdev.h> |
1da177e4 LT |
95 | |
96 | /* | |
97 | * Build xmit assembly blocks | |
98 | */ | |
99 | ||
100 | struct icmp_bxm { | |
101 | struct sk_buff *skb; | |
102 | int offset; | |
103 | int data_len; | |
104 | ||
105 | struct { | |
106 | struct icmphdr icmph; | |
b03d73e3 | 107 | __be32 times[3]; |
1da177e4 LT |
108 | } data; |
109 | int head_len; | |
f6d8bd05 | 110 | struct ip_options_data replyopts; |
1da177e4 LT |
111 | }; |
112 | ||
1da177e4 LT |
113 | /* An array of errno for error messages from dest unreach. */ |
114 | /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */ | |
115 | ||
e754834e | 116 | const struct icmp_err icmp_err_convert[] = { |
1da177e4 LT |
117 | { |
118 | .errno = ENETUNREACH, /* ICMP_NET_UNREACH */ | |
119 | .fatal = 0, | |
120 | }, | |
121 | { | |
122 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */ | |
123 | .fatal = 0, | |
124 | }, | |
125 | { | |
126 | .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */, | |
127 | .fatal = 1, | |
128 | }, | |
129 | { | |
130 | .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */ | |
131 | .fatal = 1, | |
132 | }, | |
133 | { | |
134 | .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */ | |
135 | .fatal = 0, | |
136 | }, | |
137 | { | |
138 | .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */ | |
139 | .fatal = 0, | |
140 | }, | |
141 | { | |
142 | .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */ | |
143 | .fatal = 1, | |
144 | }, | |
145 | { | |
146 | .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */ | |
147 | .fatal = 1, | |
148 | }, | |
149 | { | |
150 | .errno = ENONET, /* ICMP_HOST_ISOLATED */ | |
151 | .fatal = 1, | |
152 | }, | |
153 | { | |
154 | .errno = ENETUNREACH, /* ICMP_NET_ANO */ | |
155 | .fatal = 1, | |
156 | }, | |
157 | { | |
158 | .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */ | |
159 | .fatal = 1, | |
160 | }, | |
161 | { | |
162 | .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */ | |
163 | .fatal = 0, | |
164 | }, | |
165 | { | |
166 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */ | |
167 | .fatal = 0, | |
168 | }, | |
169 | { | |
170 | .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */ | |
171 | .fatal = 1, | |
172 | }, | |
173 | { | |
174 | .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */ | |
175 | .fatal = 1, | |
176 | }, | |
177 | { | |
178 | .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */ | |
179 | .fatal = 1, | |
180 | }, | |
181 | }; | |
4bc2f18b | 182 | EXPORT_SYMBOL(icmp_err_convert); |
1da177e4 | 183 | |
1da177e4 LT |
184 | /* |
185 | * ICMP control array. This specifies what to do with each ICMP. | |
186 | */ | |
187 | ||
188 | struct icmp_control { | |
e3e32170 | 189 | bool (*handler)(struct sk_buff *skb); |
1da177e4 LT |
190 | short error; /* This ICMP is classed as an error message */ |
191 | }; | |
192 | ||
9b5b5cff | 193 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; |
1da177e4 LT |
194 | |
195 | /* | |
196 | * The ICMP socket(s). This is the most convenient way to flow control | |
197 | * our ICMP output as well as maintain a clean interface throughout | |
198 | * all layers. All Socketless IP sends will soon be gone. | |
199 | * | |
200 | * On SMP we have one ICMP socket per-cpu. | |
201 | */ | |
4a6ad7a1 DL |
202 | static struct sock *icmp_sk(struct net *net) |
203 | { | |
046386ca | 204 | return this_cpu_read(*net->ipv4.icmp_sk); |
4a6ad7a1 | 205 | } |
1da177e4 | 206 | |
7ba91ecb | 207 | /* Called with BH disabled */ |
fdc0bde9 | 208 | static inline struct sock *icmp_xmit_lock(struct net *net) |
1da177e4 | 209 | { |
fdc0bde9 DL |
210 | struct sock *sk; |
211 | ||
fdc0bde9 DL |
212 | sk = icmp_sk(net); |
213 | ||
405666db | 214 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
215 | /* This can happen if the output path signals a |
216 | * dst_link_failure() for an outgoing ICMP packet. | |
217 | */ | |
fdc0bde9 | 218 | return NULL; |
1da177e4 | 219 | } |
fdc0bde9 | 220 | return sk; |
1da177e4 LT |
221 | } |
222 | ||
405666db | 223 | static inline void icmp_xmit_unlock(struct sock *sk) |
1da177e4 | 224 | { |
7ba91ecb | 225 | spin_unlock(&sk->sk_lock.slock); |
1da177e4 LT |
226 | } |
227 | ||
4cdf507d ED |
228 | int sysctl_icmp_msgs_per_sec __read_mostly = 1000; |
229 | int sysctl_icmp_msgs_burst __read_mostly = 50; | |
230 | ||
231 | static struct { | |
232 | spinlock_t lock; | |
233 | u32 credit; | |
234 | u32 stamp; | |
235 | } icmp_global = { | |
236 | .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock), | |
237 | }; | |
238 | ||
239 | /** | |
240 | * icmp_global_allow - Are we allowed to send one more ICMP message ? | |
241 | * | |
242 | * Uses a token bucket to limit our ICMP messages to sysctl_icmp_msgs_per_sec. | |
243 | * Returns false if we reached the limit and can not send another packet. | |
244 | * Note: called with BH disabled | |
245 | */ | |
246 | bool icmp_global_allow(void) | |
247 | { | |
248 | u32 credit, delta, incr = 0, now = (u32)jiffies; | |
249 | bool rc = false; | |
250 | ||
251 | /* Check if token bucket is empty and cannot be refilled | |
252 | * without taking the spinlock. | |
253 | */ | |
254 | if (!icmp_global.credit) { | |
255 | delta = min_t(u32, now - icmp_global.stamp, HZ); | |
256 | if (delta < HZ / 50) | |
257 | return false; | |
258 | } | |
259 | ||
260 | spin_lock(&icmp_global.lock); | |
261 | delta = min_t(u32, now - icmp_global.stamp, HZ); | |
262 | if (delta >= HZ / 50) { | |
263 | incr = sysctl_icmp_msgs_per_sec * delta / HZ ; | |
264 | if (incr) | |
265 | icmp_global.stamp = now; | |
266 | } | |
267 | credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst); | |
268 | if (credit) { | |
269 | credit--; | |
270 | rc = true; | |
271 | } | |
272 | icmp_global.credit = credit; | |
273 | spin_unlock(&icmp_global.lock); | |
274 | return rc; | |
275 | } | |
276 | EXPORT_SYMBOL(icmp_global_allow); | |
277 | ||
c0303efe JDB |
278 | static bool icmpv4_mask_allow(struct net *net, int type, int code) |
279 | { | |
280 | if (type > NR_ICMP_TYPES) | |
281 | return true; | |
282 | ||
283 | /* Don't limit PMTU discovery. */ | |
284 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
285 | return true; | |
286 | ||
287 | /* Limit if icmp type is enabled in ratemask. */ | |
288 | if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask)) | |
289 | return true; | |
290 | ||
291 | return false; | |
292 | } | |
293 | ||
294 | static bool icmpv4_global_allow(struct net *net, int type, int code) | |
295 | { | |
296 | if (icmpv4_mask_allow(net, type, code)) | |
297 | return true; | |
298 | ||
299 | if (icmp_global_allow()) | |
300 | return true; | |
301 | ||
302 | return false; | |
303 | } | |
304 | ||
1da177e4 LT |
305 | /* |
306 | * Send an ICMP frame. | |
307 | */ | |
308 | ||
4cdf507d ED |
309 | static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
310 | struct flowi4 *fl4, int type, int code) | |
1da177e4 | 311 | { |
d8d1f30b | 312 | struct dst_entry *dst = &rt->dst; |
c0303efe | 313 | struct inet_peer *peer; |
92d86829 | 314 | bool rc = true; |
c0303efe | 315 | int vif; |
1da177e4 | 316 | |
c0303efe | 317 | if (icmpv4_mask_allow(net, type, code)) |
1da177e4 LT |
318 | goto out; |
319 | ||
320 | /* No rate limit on loopback */ | |
321 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 322 | goto out; |
1da177e4 | 323 | |
c0303efe JDB |
324 | vif = l3mdev_master_ifindex(dst->dev); |
325 | peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1); | |
326 | rc = inet_peer_xrlim_allow(peer, net->ipv4.sysctl_icmp_ratelimit); | |
327 | if (peer) | |
328 | inet_putpeer(peer); | |
1da177e4 LT |
329 | out: |
330 | return rc; | |
331 | } | |
332 | ||
333 | /* | |
334 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
335 | */ | |
0388b004 | 336 | void icmp_out_count(struct net *net, unsigned char type) |
1da177e4 | 337 | { |
903fc196 | 338 | ICMPMSGOUT_INC_STATS(net, type); |
75c939bb | 339 | ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); |
1da177e4 LT |
340 | } |
341 | ||
342 | /* | |
343 | * Checksum each fragment, and on the first include the headers and final | |
344 | * checksum. | |
345 | */ | |
346 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
347 | struct sk_buff *skb) | |
348 | { | |
349 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 350 | __wsum csum; |
1da177e4 LT |
351 | |
352 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
353 | icmp_param->offset + offset, | |
354 | to, len, 0); | |
355 | ||
356 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
357 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
358 | nf_ct_attach(skb, icmp_param->skb); | |
359 | return 0; | |
360 | } | |
361 | ||
362 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
77968b78 | 363 | struct flowi4 *fl4, |
2e77d89b | 364 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 365 | { |
1e3cf683 | 366 | struct sock *sk; |
1da177e4 LT |
367 | struct sk_buff *skb; |
368 | ||
d8d1f30b | 369 | sk = icmp_sk(dev_net((*rt)->dst.dev)); |
f5fca608 | 370 | if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param, |
e905a9ed YH |
371 | icmp_param->data_len+icmp_param->head_len, |
372 | icmp_param->head_len, | |
1f8438a8 | 373 | ipc, rt, MSG_DONTWAIT) < 0) { |
5d3848bc | 374 | __ICMP_INC_STATS(sock_net(sk), ICMP_MIB_OUTERRORS); |
1e3cf683 | 375 | ip_flush_pending_frames(sk); |
1f8438a8 | 376 | } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
88c7664f | 377 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 378 | __wsum csum = 0; |
1da177e4 LT |
379 | struct sk_buff *skb1; |
380 | ||
1e3cf683 | 381 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
382 | csum = csum_add(csum, skb1->csum); |
383 | } | |
384 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
385 | (char *)icmph, | |
386 | icmp_param->head_len, csum); | |
387 | icmph->checksum = csum_fold(csum); | |
388 | skb->ip_summed = CHECKSUM_NONE; | |
77968b78 | 389 | ip_push_pending_frames(sk, fl4); |
1da177e4 LT |
390 | } |
391 | } | |
392 | ||
393 | /* | |
394 | * Driving logic for building and sending ICMP messages. | |
395 | */ | |
396 | ||
397 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
398 | { | |
1da177e4 | 399 | struct ipcm_cookie ipc; |
511c3f92 | 400 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 401 | struct net *net = dev_net(rt->dst.dev); |
77968b78 | 402 | struct flowi4 fl4; |
fdc0bde9 DL |
403 | struct sock *sk; |
404 | struct inet_sock *inet; | |
35ebf65e | 405 | __be32 daddr, saddr; |
e110861f | 406 | u32 mark = IP4_REPLY_MARK(net, skb->mark); |
c0303efe JDB |
407 | int type = icmp_param->data.icmph.type; |
408 | int code = icmp_param->data.icmph.code; | |
1da177e4 | 409 | |
91ed1e66 | 410 | if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb)) |
f00c401b | 411 | return; |
1da177e4 | 412 | |
7ba91ecb JDB |
413 | /* Needed by both icmp_global_allow and icmp_xmit_lock */ |
414 | local_bh_disable(); | |
1da177e4 | 415 | |
c0303efe JDB |
416 | /* global icmp_msgs_per_sec */ |
417 | if (!icmpv4_global_allow(net, type, code)) | |
7ba91ecb JDB |
418 | goto out_bh_enable; |
419 | ||
420 | sk = icmp_xmit_lock(net); | |
421 | if (!sk) | |
422 | goto out_bh_enable; | |
423 | inet = inet_sk(sk); | |
c0303efe | 424 | |
1da177e4 | 425 | icmp_param->data.icmph.checksum = 0; |
1da177e4 | 426 | |
35178206 | 427 | ipcm_init(&ipc); |
eddc9ec5 | 428 | inet->tos = ip_hdr(skb)->tos; |
e110861f | 429 | sk->sk_mark = mark; |
9f6abb5f | 430 | daddr = ipc.addr = ip_hdr(skb)->saddr; |
35ebf65e | 431 | saddr = fib_compute_spec_dst(skb); |
aa661581 | 432 | |
f6d8bd05 ED |
433 | if (icmp_param->replyopts.opt.opt.optlen) { |
434 | ipc.opt = &icmp_param->replyopts.opt; | |
435 | if (ipc.opt->opt.srr) | |
436 | daddr = icmp_param->replyopts.opt.opt.faddr; | |
1da177e4 | 437 | } |
77968b78 DM |
438 | memset(&fl4, 0, sizeof(fl4)); |
439 | fl4.daddr = daddr; | |
35ebf65e | 440 | fl4.saddr = saddr; |
e110861f | 441 | fl4.flowi4_mark = mark; |
e2d118a1 | 442 | fl4.flowi4_uid = sock_net_uid(net, NULL); |
77968b78 DM |
443 | fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); |
444 | fl4.flowi4_proto = IPPROTO_ICMP; | |
385add90 | 445 | fl4.flowi4_oif = l3mdev_master_ifindex(skb->dev); |
77968b78 DM |
446 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); |
447 | rt = ip_route_output_key(net, &fl4); | |
448 | if (IS_ERR(rt)) | |
449 | goto out_unlock; | |
c0303efe | 450 | if (icmpv4_xrlim_allow(net, rt, &fl4, type, code)) |
77968b78 | 451 | icmp_push_reply(icmp_param, &fl4, &ipc, &rt); |
1da177e4 LT |
452 | ip_rt_put(rt); |
453 | out_unlock: | |
405666db | 454 | icmp_xmit_unlock(sk); |
7ba91ecb JDB |
455 | out_bh_enable: |
456 | local_bh_enable(); | |
1da177e4 LT |
457 | } |
458 | ||
77968b78 DM |
459 | static struct rtable *icmp_route_lookup(struct net *net, |
460 | struct flowi4 *fl4, | |
461 | struct sk_buff *skb_in, | |
b71d1d42 | 462 | const struct iphdr *iph, |
e110861f | 463 | __be32 saddr, u8 tos, u32 mark, |
f6d460cf DM |
464 | int type, int code, |
465 | struct icmp_bxm *param) | |
466 | { | |
f6d460cf | 467 | struct rtable *rt, *rt2; |
415b3334 | 468 | struct flowi4 fl4_dec; |
f6d460cf DM |
469 | int err; |
470 | ||
77968b78 DM |
471 | memset(fl4, 0, sizeof(*fl4)); |
472 | fl4->daddr = (param->replyopts.opt.opt.srr ? | |
473 | param->replyopts.opt.opt.faddr : iph->saddr); | |
474 | fl4->saddr = saddr; | |
e110861f | 475 | fl4->flowi4_mark = mark; |
e2d118a1 | 476 | fl4->flowi4_uid = sock_net_uid(net, NULL); |
77968b78 DM |
477 | fl4->flowi4_tos = RT_TOS(tos); |
478 | fl4->flowi4_proto = IPPROTO_ICMP; | |
479 | fl4->fl4_icmp_type = type; | |
480 | fl4->fl4_icmp_code = code; | |
9d1a6c4e | 481 | fl4->flowi4_oif = l3mdev_master_ifindex(skb_dst(skb_in)->dev); |
613d09b3 | 482 | |
77968b78 | 483 | security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4)); |
3abd1ade | 484 | rt = ip_route_output_key_hash(net, fl4, skb_in); |
b23dd4fe DM |
485 | if (IS_ERR(rt)) |
486 | return rt; | |
f6d460cf DM |
487 | |
488 | /* No need to clone since we're just using its address. */ | |
489 | rt2 = rt; | |
490 | ||
9d6ec938 | 491 | rt = (struct rtable *) xfrm_lookup(net, &rt->dst, |
77968b78 | 492 | flowi4_to_flowi(fl4), NULL, 0); |
452edd59 | 493 | if (!IS_ERR(rt)) { |
f6d460cf DM |
494 | if (rt != rt2) |
495 | return rt; | |
452edd59 | 496 | } else if (PTR_ERR(rt) == -EPERM) { |
f6d460cf | 497 | rt = NULL; |
452edd59 DM |
498 | } else |
499 | return rt; | |
f6d460cf | 500 | |
415b3334 | 501 | err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET); |
f6d460cf DM |
502 | if (err) |
503 | goto relookup_failed; | |
504 | ||
9d1a6c4e | 505 | if (inet_addr_type_dev_table(net, skb_dst(skb_in)->dev, |
30bbaa19 | 506 | fl4_dec.saddr) == RTN_LOCAL) { |
415b3334 | 507 | rt2 = __ip_route_output_key(net, &fl4_dec); |
b23dd4fe DM |
508 | if (IS_ERR(rt2)) |
509 | err = PTR_ERR(rt2); | |
f6d460cf | 510 | } else { |
9d6ec938 | 511 | struct flowi4 fl4_2 = {}; |
f6d460cf DM |
512 | unsigned long orefdst; |
513 | ||
415b3334 | 514 | fl4_2.daddr = fl4_dec.saddr; |
9d6ec938 | 515 | rt2 = ip_route_output_key(net, &fl4_2); |
b23dd4fe DM |
516 | if (IS_ERR(rt2)) { |
517 | err = PTR_ERR(rt2); | |
f6d460cf | 518 | goto relookup_failed; |
b23dd4fe | 519 | } |
f6d460cf DM |
520 | /* Ugh! */ |
521 | orefdst = skb_in->_skb_refdst; /* save old refdst */ | |
773a69d6 | 522 | skb_dst_set(skb_in, NULL); |
415b3334 | 523 | err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr, |
f6d460cf DM |
524 | RT_TOS(tos), rt2->dst.dev); |
525 | ||
526 | dst_release(&rt2->dst); | |
527 | rt2 = skb_rtable(skb_in); | |
528 | skb_in->_skb_refdst = orefdst; /* restore old refdst */ | |
529 | } | |
530 | ||
531 | if (err) | |
532 | goto relookup_failed; | |
533 | ||
9d6ec938 | 534 | rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, |
415b3334 | 535 | flowi4_to_flowi(&fl4_dec), NULL, |
9d6ec938 | 536 | XFRM_LOOKUP_ICMP); |
452edd59 | 537 | if (!IS_ERR(rt2)) { |
f6d460cf | 538 | dst_release(&rt->dst); |
415b3334 | 539 | memcpy(fl4, &fl4_dec, sizeof(*fl4)); |
f6d460cf | 540 | rt = rt2; |
452edd59 DM |
541 | } else if (PTR_ERR(rt2) == -EPERM) { |
542 | if (rt) | |
543 | dst_release(&rt->dst); | |
544 | return rt2; | |
545 | } else { | |
546 | err = PTR_ERR(rt2); | |
547 | goto relookup_failed; | |
f6d460cf | 548 | } |
f6d460cf DM |
549 | return rt; |
550 | ||
551 | relookup_failed: | |
552 | if (rt) | |
553 | return rt; | |
554 | return ERR_PTR(err); | |
555 | } | |
1da177e4 LT |
556 | |
557 | /* | |
558 | * Send an ICMP message in response to a situation | |
559 | * | |
560 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
561 | * MAY send more (we do). | |
562 | * MUST NOT change this header information. | |
563 | * MUST NOT reply to a multicast/broadcast IP address. | |
564 | * MUST NOT reply to a multicast/broadcast MAC address. | |
565 | * MUST reply to only the first fragment. | |
566 | */ | |
567 | ||
9ef6b42a NS |
568 | void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, |
569 | const struct ip_options *opt) | |
1da177e4 LT |
570 | { |
571 | struct iphdr *iph; | |
572 | int room; | |
8d9ba388 | 573 | struct icmp_bxm icmp_param; |
511c3f92 | 574 | struct rtable *rt = skb_rtable(skb_in); |
1da177e4 | 575 | struct ipcm_cookie ipc; |
77968b78 | 576 | struct flowi4 fl4; |
a61ced5d | 577 | __be32 saddr; |
1da177e4 | 578 | u8 tos; |
e110861f | 579 | u32 mark; |
dde1bc0e | 580 | struct net *net; |
4a6ad7a1 | 581 | struct sock *sk; |
1da177e4 LT |
582 | |
583 | if (!rt) | |
584 | goto out; | |
d8d1f30b | 585 | net = dev_net(rt->dst.dev); |
1da177e4 LT |
586 | |
587 | /* | |
588 | * Find the original header. It is expected to be valid, of course. | |
589 | * Check this, icmp_send is called from the most obscure devices | |
590 | * sometimes. | |
591 | */ | |
eddc9ec5 | 592 | iph = ip_hdr(skb_in); |
1da177e4 | 593 | |
27a884dc | 594 | if ((u8 *)iph < skb_in->head || |
f7c0c2ae SH |
595 | (skb_network_header(skb_in) + sizeof(*iph)) > |
596 | skb_tail_pointer(skb_in)) | |
1da177e4 LT |
597 | goto out; |
598 | ||
599 | /* | |
600 | * No replies to physical multicast/broadcast | |
601 | */ | |
602 | if (skb_in->pkt_type != PACKET_HOST) | |
603 | goto out; | |
604 | ||
605 | /* | |
606 | * Now check at the protocol level | |
607 | */ | |
608 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
609 | goto out; | |
610 | ||
611 | /* | |
612 | * Only reply to fragment 0. We byte re-order the constant | |
613 | * mask for efficiency. | |
614 | */ | |
615 | if (iph->frag_off & htons(IP_OFFSET)) | |
616 | goto out; | |
617 | ||
618 | /* | |
619 | * If we send an ICMP error to an ICMP error a mess would result.. | |
620 | */ | |
621 | if (icmp_pointers[type].error) { | |
622 | /* | |
623 | * We are an error, check if we are replying to an | |
624 | * ICMP error | |
625 | */ | |
626 | if (iph->protocol == IPPROTO_ICMP) { | |
627 | u8 _inner_type, *itp; | |
628 | ||
629 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 630 | skb_network_header(skb_in) + |
1da177e4 LT |
631 | (iph->ihl << 2) + |
632 | offsetof(struct icmphdr, | |
633 | type) - | |
634 | skb_in->data, | |
635 | sizeof(_inner_type), | |
636 | &_inner_type); | |
51456b29 | 637 | if (!itp) |
1da177e4 LT |
638 | goto out; |
639 | ||
640 | /* | |
641 | * Assume any unknown ICMP type is an error. This | |
642 | * isn't specified by the RFC, but think about it.. | |
643 | */ | |
644 | if (*itp > NR_ICMP_TYPES || | |
645 | icmp_pointers[*itp].error) | |
646 | goto out; | |
647 | } | |
648 | } | |
649 | ||
7ba91ecb JDB |
650 | /* Needed by both icmp_global_allow and icmp_xmit_lock */ |
651 | local_bh_disable(); | |
c0303efe | 652 | |
849a44de JDB |
653 | /* Check global sysctl_icmp_msgs_per_sec ratelimit, unless |
654 | * incoming dev is loopback. If outgoing dev change to not be | |
655 | * loopback, then peer ratelimit still work (in icmpv4_xrlim_allow) | |
656 | */ | |
657 | if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) && | |
658 | !icmpv4_global_allow(net, type, code)) | |
7ba91ecb JDB |
659 | goto out_bh_enable; |
660 | ||
661 | sk = icmp_xmit_lock(net); | |
662 | if (!sk) | |
663 | goto out_bh_enable; | |
1da177e4 LT |
664 | |
665 | /* | |
666 | * Construct source address and options. | |
667 | */ | |
668 | ||
669 | saddr = iph->daddr; | |
02a6d613 | 670 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
671 | struct net_device *dev = NULL; |
672 | ||
685c7944 | 673 | rcu_read_lock(); |
c7537967 DM |
674 | if (rt_is_input_route(rt) && |
675 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) | |
92101b3b | 676 | dev = dev_get_by_index_rcu(net, inet_iif(skb_in)); |
6e1d9103 | 677 | |
685c7944 | 678 | if (dev) |
6e1d9103 | 679 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
685c7944 | 680 | else |
1c2fb7f9 | 681 | saddr = 0; |
685c7944 | 682 | rcu_read_unlock(); |
1c2fb7f9 | 683 | } |
1da177e4 LT |
684 | |
685 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
686 | IPTOS_PREC_INTERNETCONTROL) : | |
687 | iph->tos; | |
e110861f | 688 | mark = IP4_REPLY_MARK(net, skb_in->mark); |
1da177e4 | 689 | |
9ef6b42a | 690 | if (__ip_options_echo(net, &icmp_param.replyopts.opt.opt, skb_in, opt)) |
fa60cf7f | 691 | goto out_unlock; |
1da177e4 LT |
692 | |
693 | ||
694 | /* | |
695 | * Prepare data for ICMP header. | |
696 | */ | |
697 | ||
8d9ba388 JDB |
698 | icmp_param.data.icmph.type = type; |
699 | icmp_param.data.icmph.code = code; | |
700 | icmp_param.data.icmph.un.gateway = info; | |
701 | icmp_param.data.icmph.checksum = 0; | |
702 | icmp_param.skb = skb_in; | |
703 | icmp_param.offset = skb_network_offset(skb_in); | |
405666db | 704 | inet_sk(sk)->tos = tos; |
e110861f | 705 | sk->sk_mark = mark; |
35178206 | 706 | ipcm_init(&ipc); |
1da177e4 | 707 | ipc.addr = iph->saddr; |
8d9ba388 | 708 | ipc.opt = &icmp_param.replyopts.opt; |
1da177e4 | 709 | |
e110861f | 710 | rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark, |
8d9ba388 | 711 | type, code, &icmp_param); |
f6d460cf DM |
712 | if (IS_ERR(rt)) |
713 | goto out_unlock; | |
1da177e4 | 714 | |
c0303efe | 715 | /* peer icmp_ratelimit */ |
a48eff12 | 716 | if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code)) |
1da177e4 LT |
717 | goto ende; |
718 | ||
719 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
720 | ||
d8d1f30b | 721 | room = dst_mtu(&rt->dst); |
1da177e4 LT |
722 | if (room > 576) |
723 | room = 576; | |
8d9ba388 | 724 | room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; |
1da177e4 LT |
725 | room -= sizeof(struct icmphdr); |
726 | ||
8d9ba388 JDB |
727 | icmp_param.data_len = skb_in->len - icmp_param.offset; |
728 | if (icmp_param.data_len > room) | |
729 | icmp_param.data_len = room; | |
730 | icmp_param.head_len = sizeof(struct icmphdr); | |
1da177e4 | 731 | |
8d9ba388 | 732 | icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); |
1da177e4 LT |
733 | ende: |
734 | ip_rt_put(rt); | |
735 | out_unlock: | |
405666db | 736 | icmp_xmit_unlock(sk); |
7ba91ecb JDB |
737 | out_bh_enable: |
738 | local_bh_enable(); | |
1da177e4 LT |
739 | out:; |
740 | } | |
9ef6b42a | 741 | EXPORT_SYMBOL(__icmp_send); |
1da177e4 LT |
742 | |
743 | ||
1de9243b DM |
744 | static void icmp_socket_deliver(struct sk_buff *skb, u32 info) |
745 | { | |
746 | const struct iphdr *iph = (const struct iphdr *) skb->data; | |
747 | const struct net_protocol *ipprot; | |
748 | int protocol = iph->protocol; | |
749 | ||
f0a70e90 DM |
750 | /* Checkin full IP header plus 8 bytes of protocol to |
751 | * avoid additional coding at protocol handlers. | |
752 | */ | |
7304fe46 | 753 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) { |
5d3848bc | 754 | __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); |
f0a70e90 | 755 | return; |
7304fe46 | 756 | } |
f0a70e90 | 757 | |
1de9243b DM |
758 | raw_icmp_error(skb, protocol, info); |
759 | ||
1de9243b DM |
760 | ipprot = rcu_dereference(inet_protos[protocol]); |
761 | if (ipprot && ipprot->err_handler) | |
762 | ipprot->err_handler(skb, info); | |
1de9243b DM |
763 | } |
764 | ||
8ed1dc44 HFS |
765 | static bool icmp_tag_validation(int proto) |
766 | { | |
767 | bool ok; | |
768 | ||
769 | rcu_read_lock(); | |
770 | ok = rcu_dereference(inet_protos[proto])->icmp_strict_tag_validation; | |
771 | rcu_read_unlock(); | |
772 | return ok; | |
773 | } | |
774 | ||
1da177e4 | 775 | /* |
258bbb1b | 776 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEEDED, ICMP_QUENCH, and |
08578d8d | 777 | * ICMP_PARAMETERPROB. |
1da177e4 LT |
778 | */ |
779 | ||
e3e32170 | 780 | static bool icmp_unreach(struct sk_buff *skb) |
1da177e4 | 781 | { |
b71d1d42 | 782 | const struct iphdr *iph; |
1da177e4 | 783 | struct icmphdr *icmph; |
dde1bc0e | 784 | struct net *net; |
f9242b6b | 785 | u32 info = 0; |
dde1bc0e | 786 | |
adf30907 | 787 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
788 | |
789 | /* | |
790 | * Incomplete header ? | |
791 | * Only checks for the IP header, there should be an | |
792 | * additional check for longer headers in upper levels. | |
793 | */ | |
794 | ||
795 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
796 | goto out_err; | |
797 | ||
88c7664f | 798 | icmph = icmp_hdr(skb); |
b71d1d42 | 799 | iph = (const struct iphdr *)skb->data; |
1da177e4 LT |
800 | |
801 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
802 | goto out_err; | |
803 | ||
258bbb1b MC |
804 | switch (icmph->type) { |
805 | case ICMP_DEST_UNREACH: | |
1da177e4 LT |
806 | switch (icmph->code & 15) { |
807 | case ICMP_NET_UNREACH: | |
808 | case ICMP_HOST_UNREACH: | |
809 | case ICMP_PROT_UNREACH: | |
810 | case ICMP_PORT_UNREACH: | |
811 | break; | |
812 | case ICMP_FRAG_NEEDED: | |
8ed1dc44 HFS |
813 | /* for documentation of the ip_no_pmtu_disc |
814 | * values please see | |
815 | * Documentation/networking/ip-sysctl.txt | |
816 | */ | |
817 | switch (net->ipv4.sysctl_ip_no_pmtu_disc) { | |
818 | default: | |
ba7a46f1 JP |
819 | net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n", |
820 | &iph->daddr); | |
8ed1dc44 HFS |
821 | break; |
822 | case 2: | |
823 | goto out; | |
824 | case 3: | |
825 | if (!icmp_tag_validation(iph->protocol)) | |
826 | goto out; | |
827 | /* fall through */ | |
828 | case 0: | |
46517008 | 829 | info = ntohs(icmph->un.frag.mtu); |
1da177e4 LT |
830 | } |
831 | break; | |
832 | case ICMP_SR_FAILED: | |
ba7a46f1 JP |
833 | net_dbg_ratelimited("%pI4: Source Route Failed\n", |
834 | &iph->daddr); | |
1da177e4 LT |
835 | break; |
836 | default: | |
837 | break; | |
838 | } | |
839 | if (icmph->code > NR_ICMP_UNREACH) | |
840 | goto out; | |
258bbb1b MC |
841 | break; |
842 | case ICMP_PARAMETERPROB: | |
1da177e4 | 843 | info = ntohl(icmph->un.gateway) >> 24; |
258bbb1b MC |
844 | break; |
845 | case ICMP_TIME_EXCEEDED: | |
846 | __ICMP_INC_STATS(net, ICMP_MIB_INTIMEEXCDS); | |
847 | if (icmph->code == ICMP_EXC_FRAGTIME) | |
848 | goto out; | |
849 | break; | |
850 | } | |
1da177e4 LT |
851 | |
852 | /* | |
853 | * Throw it at our lower layers | |
854 | * | |
855 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
856 | * header. | |
857 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
858 | * transport layer. | |
859 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
860 | * transport layer. | |
861 | */ | |
862 | ||
863 | /* | |
25985edc | 864 | * Check the other end isn't violating RFC 1122. Some routers send |
1da177e4 LT |
865 | * bogus responses to broadcast frames. If you see this message |
866 | * first check your netmask matches at both ends, if it does then | |
867 | * get the other vendor to fix their kit. | |
868 | */ | |
869 | ||
b34a95ee | 870 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
30bbaa19 | 871 | inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) { |
e87cc472 JP |
872 | net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n", |
873 | &ip_hdr(skb)->saddr, | |
874 | icmph->type, icmph->code, | |
875 | &iph->daddr, skb->dev->name); | |
1da177e4 LT |
876 | goto out; |
877 | } | |
878 | ||
1de9243b | 879 | icmp_socket_deliver(skb, info); |
1da177e4 LT |
880 | |
881 | out: | |
e3e32170 | 882 | return true; |
1da177e4 | 883 | out_err: |
5d3848bc | 884 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
e3e32170 | 885 | return false; |
1da177e4 LT |
886 | } |
887 | ||
888 | ||
889 | /* | |
890 | * Handle ICMP_REDIRECT. | |
891 | */ | |
892 | ||
e3e32170 | 893 | static bool icmp_redirect(struct sk_buff *skb) |
1da177e4 | 894 | { |
94206125 | 895 | if (skb->len < sizeof(struct iphdr)) { |
5d3848bc | 896 | __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS); |
e3e32170 | 897 | return false; |
94206125 | 898 | } |
1da177e4 | 899 | |
e3e32170 RJ |
900 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) { |
901 | /* there aught to be a stat */ | |
902 | return false; | |
903 | } | |
c319b4d7 | 904 | |
d3351b75 | 905 | icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway); |
e3e32170 | 906 | return true; |
1da177e4 LT |
907 | } |
908 | ||
909 | /* | |
910 | * Handle ICMP_ECHO ("ping") requests. | |
911 | * | |
912 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
913 | * requests. | |
914 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
915 | * included in the reply. | |
916 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
917 | * echo requests, MUST have default=NOT. | |
918 | * See also WRT handling of options once they are done and working. | |
919 | */ | |
920 | ||
e3e32170 | 921 | static bool icmp_echo(struct sk_buff *skb) |
1da177e4 | 922 | { |
b34a95ee PE |
923 | struct net *net; |
924 | ||
adf30907 | 925 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 926 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
927 | struct icmp_bxm icmp_param; |
928 | ||
88c7664f | 929 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
930 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
931 | icmp_param.skb = skb; | |
932 | icmp_param.offset = 0; | |
933 | icmp_param.data_len = skb->len; | |
934 | icmp_param.head_len = sizeof(struct icmphdr); | |
935 | icmp_reply(&icmp_param, skb); | |
936 | } | |
e3e32170 RJ |
937 | /* should there be an ICMP stat for ignored echos? */ |
938 | return true; | |
1da177e4 LT |
939 | } |
940 | ||
941 | /* | |
942 | * Handle ICMP Timestamp requests. | |
943 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
944 | * SHOULD be in the kernel for minimum random latency. | |
945 | * MUST be accurate to a few minutes. | |
946 | * MUST be updated at least at 15Hz. | |
947 | */ | |
e3e32170 | 948 | static bool icmp_timestamp(struct sk_buff *skb) |
1da177e4 | 949 | { |
1da177e4 LT |
950 | struct icmp_bxm icmp_param; |
951 | /* | |
952 | * Too short. | |
953 | */ | |
954 | if (skb->len < 4) | |
955 | goto out_err; | |
956 | ||
957 | /* | |
958 | * Fill in the current time as ms since midnight UT: | |
959 | */ | |
822c8685 | 960 | icmp_param.data.times[1] = inet_current_timestamp(); |
1da177e4 | 961 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
15285402 GS |
962 | |
963 | BUG_ON(skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)); | |
964 | ||
88c7664f | 965 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
966 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
967 | icmp_param.data.icmph.code = 0; | |
968 | icmp_param.skb = skb; | |
969 | icmp_param.offset = 0; | |
970 | icmp_param.data_len = 0; | |
971 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
972 | icmp_reply(&icmp_param, skb); | |
e3e32170 RJ |
973 | return true; |
974 | ||
1da177e4 | 975 | out_err: |
5d3848bc | 976 | __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
e3e32170 | 977 | return false; |
1da177e4 LT |
978 | } |
979 | ||
e3e32170 | 980 | static bool icmp_discard(struct sk_buff *skb) |
1da177e4 | 981 | { |
e3e32170 RJ |
982 | /* pretend it was a success */ |
983 | return true; | |
1da177e4 LT |
984 | } |
985 | ||
986 | /* | |
987 | * Deal with incoming ICMP packets. | |
988 | */ | |
989 | int icmp_rcv(struct sk_buff *skb) | |
990 | { | |
991 | struct icmphdr *icmph; | |
511c3f92 | 992 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 993 | struct net *net = dev_net(rt->dst.dev); |
e3e32170 | 994 | bool success; |
1da177e4 | 995 | |
aebcf82c | 996 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 997 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
998 | int nh; |
999 | ||
def8b4fa | 1000 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
1001 | XFRM_STATE_ICMP)) |
1002 | goto drop; | |
1003 | ||
8b7817f3 HX |
1004 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
1005 | goto drop; | |
1006 | ||
1007 | nh = skb_network_offset(skb); | |
1008 | skb_set_network_header(skb, sizeof(*icmph)); | |
1009 | ||
1010 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
1011 | goto drop; | |
1012 | ||
1013 | skb_set_network_header(skb, nh); | |
1014 | } | |
1015 | ||
5d3848bc | 1016 | __ICMP_INC_STATS(net, ICMP_MIB_INMSGS); |
1da177e4 | 1017 | |
29a96e1f TH |
1018 | if (skb_checksum_simple_validate(skb)) |
1019 | goto csum_error; | |
1da177e4 | 1020 | |
8cf22943 HX |
1021 | if (!pskb_pull(skb, sizeof(*icmph))) |
1022 | goto error; | |
1da177e4 | 1023 | |
88c7664f | 1024 | icmph = icmp_hdr(skb); |
1da177e4 | 1025 | |
214d3f1f | 1026 | ICMPMSGIN_INC_STATS(net, icmph->type); |
1da177e4 LT |
1027 | /* |
1028 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
1029 | * | |
1030 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1031 | * discarded. | |
1032 | */ | |
1033 | if (icmph->type > NR_ICMP_TYPES) | |
1034 | goto error; | |
1035 | ||
1036 | ||
1037 | /* | |
1038 | * Parse the ICMP message | |
1039 | */ | |
1040 | ||
e905a9ed | 1041 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1042 | /* |
1043 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1044 | * silently ignored (we let user decide with a sysctl). | |
1045 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1046 | * discarded if to broadcast/multicast. | |
1047 | */ | |
4c866aa7 AK |
1048 | if ((icmph->type == ICMP_ECHO || |
1049 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1050 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1051 | goto error; |
1052 | } | |
1053 | if (icmph->type != ICMP_ECHO && | |
1054 | icmph->type != ICMP_TIMESTAMP && | |
1055 | icmph->type != ICMP_ADDRESS && | |
1056 | icmph->type != ICMP_ADDRESSREPLY) { | |
1057 | goto error; | |
e905a9ed | 1058 | } |
1da177e4 LT |
1059 | } |
1060 | ||
e3e32170 RJ |
1061 | success = icmp_pointers[icmph->type].handler(skb); |
1062 | ||
1063 | if (success) { | |
1064 | consume_skb(skb); | |
f91c58d6 | 1065 | return NET_RX_SUCCESS; |
e3e32170 | 1066 | } |
1da177e4 LT |
1067 | |
1068 | drop: | |
1069 | kfree_skb(skb); | |
f91c58d6 | 1070 | return NET_RX_DROP; |
6a5dc9e5 | 1071 | csum_error: |
5d3848bc | 1072 | __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS); |
1da177e4 | 1073 | error: |
5d3848bc | 1074 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1075 | goto drop; |
1076 | } | |
1077 | ||
32bbd879 | 1078 | int icmp_err(struct sk_buff *skb, u32 info) |
5b052042 LW |
1079 | { |
1080 | struct iphdr *iph = (struct iphdr *)skb->data; | |
6d0bfe22 LC |
1081 | int offset = iph->ihl<<2; |
1082 | struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset); | |
5b052042 LW |
1083 | int type = icmp_hdr(skb)->type; |
1084 | int code = icmp_hdr(skb)->code; | |
1085 | struct net *net = dev_net(skb->dev); | |
1086 | ||
1087 | /* | |
1088 | * Use ping_err to handle all icmp errors except those | |
1089 | * triggered by ICMP_ECHOREPLY which sent from kernel. | |
1090 | */ | |
1091 | if (icmph->type != ICMP_ECHOREPLY) { | |
6d0bfe22 | 1092 | ping_err(skb, offset, info); |
32bbd879 | 1093 | return 0; |
5b052042 LW |
1094 | } |
1095 | ||
1096 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
d888f396 | 1097 | ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ICMP); |
5b052042 | 1098 | else if (type == ICMP_REDIRECT) |
1042caa7 | 1099 | ipv4_redirect(skb, net, 0, IPPROTO_ICMP); |
32bbd879 SB |
1100 | |
1101 | return 0; | |
5b052042 LW |
1102 | } |
1103 | ||
1da177e4 LT |
1104 | /* |
1105 | * This table is the definition of how we handle ICMP. | |
1106 | */ | |
9b5b5cff | 1107 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1108 | [ICMP_ECHOREPLY] = { |
c319b4d7 | 1109 | .handler = ping_rcv, |
1da177e4 LT |
1110 | }, |
1111 | [1] = { | |
1da177e4 LT |
1112 | .handler = icmp_discard, |
1113 | .error = 1, | |
1114 | }, | |
1115 | [2] = { | |
1da177e4 LT |
1116 | .handler = icmp_discard, |
1117 | .error = 1, | |
1118 | }, | |
1119 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1120 | .handler = icmp_unreach, |
1121 | .error = 1, | |
1122 | }, | |
1123 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1124 | .handler = icmp_unreach, |
1125 | .error = 1, | |
1126 | }, | |
1127 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1128 | .handler = icmp_redirect, |
1129 | .error = 1, | |
1130 | }, | |
1131 | [6] = { | |
1da177e4 LT |
1132 | .handler = icmp_discard, |
1133 | .error = 1, | |
1134 | }, | |
1135 | [7] = { | |
1da177e4 LT |
1136 | .handler = icmp_discard, |
1137 | .error = 1, | |
1138 | }, | |
1139 | [ICMP_ECHO] = { | |
1da177e4 LT |
1140 | .handler = icmp_echo, |
1141 | }, | |
1142 | [9] = { | |
1da177e4 LT |
1143 | .handler = icmp_discard, |
1144 | .error = 1, | |
1145 | }, | |
1146 | [10] = { | |
1da177e4 LT |
1147 | .handler = icmp_discard, |
1148 | .error = 1, | |
1149 | }, | |
1150 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1151 | .handler = icmp_unreach, |
1152 | .error = 1, | |
1153 | }, | |
1154 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1155 | .handler = icmp_unreach, |
1156 | .error = 1, | |
1157 | }, | |
1158 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1159 | .handler = icmp_timestamp, |
1160 | }, | |
1161 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1162 | .handler = icmp_discard, |
1163 | }, | |
1164 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1165 | .handler = icmp_discard, |
1166 | }, | |
e905a9ed | 1167 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1168 | .handler = icmp_discard, |
1169 | }, | |
1170 | [ICMP_ADDRESS] = { | |
838942a5 | 1171 | .handler = icmp_discard, |
1da177e4 LT |
1172 | }, |
1173 | [ICMP_ADDRESSREPLY] = { | |
838942a5 | 1174 | .handler = icmp_discard, |
1da177e4 LT |
1175 | }, |
1176 | }; | |
1177 | ||
4a6ad7a1 | 1178 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1179 | { |
1da177e4 LT |
1180 | int i; |
1181 | ||
5c8cafd6 | 1182 | for_each_possible_cpu(i) |
349c9e3c ED |
1183 | inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i)); |
1184 | free_percpu(net->ipv4.icmp_sk); | |
4a6ad7a1 | 1185 | net->ipv4.icmp_sk = NULL; |
a5710d65 | 1186 | } |
1da177e4 | 1187 | |
263173af | 1188 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1189 | { |
a5710d65 DL |
1190 | int i, err; |
1191 | ||
349c9e3c ED |
1192 | net->ipv4.icmp_sk = alloc_percpu(struct sock *); |
1193 | if (!net->ipv4.icmp_sk) | |
79c91159 DL |
1194 | return -ENOMEM; |
1195 | ||
a5710d65 | 1196 | for_each_possible_cpu(i) { |
1e3cf683 | 1197 | struct sock *sk; |
1da177e4 | 1198 | |
c1e9894d DL |
1199 | err = inet_ctl_sock_create(&sk, PF_INET, |
1200 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1201 | if (err < 0) |
a5710d65 | 1202 | goto fail; |
1da177e4 | 1203 | |
349c9e3c | 1204 | *per_cpu_ptr(net->ipv4.icmp_sk, i) = sk; |
1da177e4 LT |
1205 | |
1206 | /* Enough space for 2 64K ICMP packets, including | |
87fb4b7b | 1207 | * sk_buff/skb_shared_info struct overhead. |
1da177e4 | 1208 | */ |
87fb4b7b | 1209 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
1da177e4 | 1210 | |
b3a5b6cc ED |
1211 | /* |
1212 | * Speedup sock_wfree() | |
1213 | */ | |
1214 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
c1e9894d | 1215 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1216 | } |
a24022e1 PE |
1217 | |
1218 | /* Control parameters for ECHO replies. */ | |
1219 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1220 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1221 | ||
1222 | /* Control parameter - ignore bogus broadcast responses? */ | |
1223 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1224 | ||
1225 | /* | |
1226 | * Configurable global rate limit. | |
1227 | * | |
1228 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1229 | * bucket ratemask defines which icmp types are ratelimited by | |
1230 | * setting it's bit position. | |
1231 | * | |
1232 | * default: | |
1233 | * dest unreachable (3), source quench (4), | |
1234 | * time exceeded (11), parameter problem (12) | |
1235 | */ | |
1236 | ||
1237 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1238 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1239 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1240 | ||
a5710d65 DL |
1241 | return 0; |
1242 | ||
1243 | fail: | |
e9128c14 | 1244 | icmp_sk_exit(net); |
a5710d65 | 1245 | return err; |
1da177e4 LT |
1246 | } |
1247 | ||
4a6ad7a1 DL |
1248 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1249 | .init = icmp_sk_init, | |
1250 | .exit = icmp_sk_exit, | |
1251 | }; | |
1252 | ||
1253 | int __init icmp_init(void) | |
1254 | { | |
959d2726 | 1255 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 | 1256 | } |