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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NET3: Implementation of the ICMP protocol layer. | |
3 | * | |
4 | * Alan Cox, <alan@redhat.com> | |
5 | * | |
6 | * Version: $Id: icmp.c,v 1.85 2002/02/01 22:01:03 davem Exp $ | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | * | |
13 | * Some of the function names and the icmp unreach table for this | |
14 | * module were derived from [icmp.c 1.0.11 06/02/93] by | |
15 | * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting. | |
16 | * Other than that this module is a complete rewrite. | |
17 | * | |
18 | * Fixes: | |
19 | * Clemens Fruhwirth : introduce global icmp rate limiting | |
20 | * with icmp type masking ability instead | |
21 | * of broken per type icmp timeouts. | |
22 | * Mike Shaver : RFC1122 checks. | |
23 | * Alan Cox : Multicast ping reply as self. | |
24 | * Alan Cox : Fix atomicity lockup in ip_build_xmit | |
25 | * call. | |
26 | * Alan Cox : Added 216,128 byte paths to the MTU | |
27 | * code. | |
28 | * Martin Mares : RFC1812 checks. | |
29 | * Martin Mares : Can be configured to follow redirects | |
30 | * if acting as a router _without_ a | |
31 | * routing protocol (RFC 1812). | |
32 | * Martin Mares : Echo requests may be configured to | |
33 | * be ignored (RFC 1812). | |
34 | * Martin Mares : Limitation of ICMP error message | |
35 | * transmit rate (RFC 1812). | |
36 | * Martin Mares : TOS and Precedence set correctly | |
37 | * (RFC 1812). | |
38 | * Martin Mares : Now copying as much data from the | |
39 | * original packet as we can without | |
40 | * exceeding 576 bytes (RFC 1812). | |
41 | * Willy Konynenberg : Transparent proxying support. | |
42 | * Keith Owens : RFC1191 correction for 4.2BSD based | |
43 | * path MTU bug. | |
44 | * Thomas Quinot : ICMP Dest Unreach codes up to 15 are | |
45 | * valid (RFC 1812). | |
46 | * Andi Kleen : Check all packet lengths properly | |
47 | * and moved all kfree_skb() up to | |
48 | * icmp_rcv. | |
49 | * Andi Kleen : Move the rate limit bookkeeping | |
50 | * into the dest entry and use a token | |
51 | * bucket filter (thanks to ANK). Make | |
52 | * the rates sysctl configurable. | |
53 | * Yu Tianli : Fixed two ugly bugs in icmp_send | |
54 | * - IP option length was accounted wrongly | |
55 | * - ICMP header length was not accounted | |
56 | * at all. | |
57 | * Tristan Greaves : Added sysctl option to ignore bogus | |
58 | * broadcast responses from broken routers. | |
59 | * | |
60 | * To Fix: | |
61 | * | |
62 | * - Should use skb_pull() instead of all the manual checking. | |
63 | * This would also greatly simply some upper layer error handlers. --AK | |
64 | * | |
65 | */ | |
66 | ||
1da177e4 LT |
67 | #include <linux/module.h> |
68 | #include <linux/types.h> | |
69 | #include <linux/jiffies.h> | |
70 | #include <linux/kernel.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/socket.h> | |
73 | #include <linux/in.h> | |
74 | #include <linux/inet.h> | |
14c85021 | 75 | #include <linux/inetdevice.h> |
1da177e4 LT |
76 | #include <linux/netdevice.h> |
77 | #include <linux/string.h> | |
78 | #include <linux/netfilter_ipv4.h> | |
79 | #include <net/snmp.h> | |
80 | #include <net/ip.h> | |
81 | #include <net/route.h> | |
82 | #include <net/protocol.h> | |
83 | #include <net/icmp.h> | |
84 | #include <net/tcp.h> | |
85 | #include <net/udp.h> | |
86 | #include <net/raw.h> | |
87 | #include <linux/skbuff.h> | |
88 | #include <net/sock.h> | |
89 | #include <linux/errno.h> | |
90 | #include <linux/timer.h> | |
91 | #include <linux/init.h> | |
92 | #include <asm/system.h> | |
93 | #include <asm/uaccess.h> | |
94 | #include <net/checksum.h> | |
8b7817f3 | 95 | #include <net/xfrm.h> |
1da177e4 LT |
96 | |
97 | /* | |
98 | * Build xmit assembly blocks | |
99 | */ | |
100 | ||
101 | struct icmp_bxm { | |
102 | struct sk_buff *skb; | |
103 | int offset; | |
104 | int data_len; | |
105 | ||
106 | struct { | |
107 | struct icmphdr icmph; | |
b03d73e3 | 108 | __be32 times[3]; |
1da177e4 LT |
109 | } data; |
110 | int head_len; | |
111 | struct ip_options replyopts; | |
112 | unsigned char optbuf[40]; | |
113 | }; | |
114 | ||
115 | /* | |
116 | * Statistics | |
117 | */ | |
ba89966c | 118 | DEFINE_SNMP_STAT(struct icmp_mib, icmp_statistics) __read_mostly; |
96793b48 | 119 | DEFINE_SNMP_STAT(struct icmpmsg_mib, icmpmsg_statistics) __read_mostly; |
1da177e4 LT |
120 | |
121 | /* An array of errno for error messages from dest unreach. */ | |
122 | /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */ | |
123 | ||
124 | struct icmp_err icmp_err_convert[] = { | |
125 | { | |
126 | .errno = ENETUNREACH, /* ICMP_NET_UNREACH */ | |
127 | .fatal = 0, | |
128 | }, | |
129 | { | |
130 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */ | |
131 | .fatal = 0, | |
132 | }, | |
133 | { | |
134 | .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */, | |
135 | .fatal = 1, | |
136 | }, | |
137 | { | |
138 | .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */ | |
139 | .fatal = 1, | |
140 | }, | |
141 | { | |
142 | .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */ | |
143 | .fatal = 0, | |
144 | }, | |
145 | { | |
146 | .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */ | |
147 | .fatal = 0, | |
148 | }, | |
149 | { | |
150 | .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */ | |
151 | .fatal = 1, | |
152 | }, | |
153 | { | |
154 | .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */ | |
155 | .fatal = 1, | |
156 | }, | |
157 | { | |
158 | .errno = ENONET, /* ICMP_HOST_ISOLATED */ | |
159 | .fatal = 1, | |
160 | }, | |
161 | { | |
162 | .errno = ENETUNREACH, /* ICMP_NET_ANO */ | |
163 | .fatal = 1, | |
164 | }, | |
165 | { | |
166 | .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */ | |
167 | .fatal = 1, | |
168 | }, | |
169 | { | |
170 | .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */ | |
171 | .fatal = 0, | |
172 | }, | |
173 | { | |
174 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */ | |
175 | .fatal = 0, | |
176 | }, | |
177 | { | |
178 | .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */ | |
179 | .fatal = 1, | |
180 | }, | |
181 | { | |
182 | .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */ | |
183 | .fatal = 1, | |
184 | }, | |
185 | { | |
186 | .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */ | |
187 | .fatal = 1, | |
188 | }, | |
189 | }; | |
190 | ||
1da177e4 LT |
191 | /* |
192 | * ICMP control array. This specifies what to do with each ICMP. | |
193 | */ | |
194 | ||
195 | struct icmp_control { | |
1da177e4 LT |
196 | void (*handler)(struct sk_buff *skb); |
197 | short error; /* This ICMP is classed as an error message */ | |
198 | }; | |
199 | ||
9b5b5cff | 200 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; |
1da177e4 LT |
201 | |
202 | /* | |
203 | * The ICMP socket(s). This is the most convenient way to flow control | |
204 | * our ICMP output as well as maintain a clean interface throughout | |
205 | * all layers. All Socketless IP sends will soon be gone. | |
206 | * | |
207 | * On SMP we have one ICMP socket per-cpu. | |
208 | */ | |
4a6ad7a1 DL |
209 | static struct sock *icmp_sk(struct net *net) |
210 | { | |
211 | return net->ipv4.icmp_sk[smp_processor_id()]; | |
212 | } | |
1da177e4 | 213 | |
405666db | 214 | static inline int icmp_xmit_lock(struct sock *sk) |
1da177e4 LT |
215 | { |
216 | local_bh_disable(); | |
217 | ||
405666db | 218 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
219 | /* This can happen if the output path signals a |
220 | * dst_link_failure() for an outgoing ICMP packet. | |
221 | */ | |
222 | local_bh_enable(); | |
223 | return 1; | |
224 | } | |
225 | return 0; | |
226 | } | |
227 | ||
405666db | 228 | static inline void icmp_xmit_unlock(struct sock *sk) |
1da177e4 | 229 | { |
405666db | 230 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
231 | } |
232 | ||
233 | /* | |
234 | * Send an ICMP frame. | |
235 | */ | |
236 | ||
237 | /* | |
238 | * Check transmit rate limitation for given message. | |
239 | * The rate information is held in the destination cache now. | |
240 | * This function is generic and could be used for other purposes | |
241 | * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov. | |
242 | * | |
243 | * Note that the same dst_entry fields are modified by functions in | |
244 | * route.c too, but these work for packet destinations while xrlim_allow | |
245 | * works for icmp destinations. This means the rate limiting information | |
246 | * for one "ip object" is shared - and these ICMPs are twice limited: | |
247 | * by source and by destination. | |
248 | * | |
249 | * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate | |
250 | * SHOULD allow setting of rate limits | |
251 | * | |
252 | * Shared between ICMPv4 and ICMPv6. | |
253 | */ | |
254 | #define XRLIM_BURST_FACTOR 6 | |
255 | int xrlim_allow(struct dst_entry *dst, int timeout) | |
256 | { | |
69a73829 | 257 | unsigned long now, token = dst->rate_tokens; |
1da177e4 LT |
258 | int rc = 0; |
259 | ||
260 | now = jiffies; | |
69a73829 | 261 | token += now - dst->rate_last; |
1da177e4 | 262 | dst->rate_last = now; |
69a73829 ED |
263 | if (token > XRLIM_BURST_FACTOR * timeout) |
264 | token = XRLIM_BURST_FACTOR * timeout; | |
265 | if (token >= timeout) { | |
266 | token -= timeout; | |
1da177e4 LT |
267 | rc = 1; |
268 | } | |
69a73829 | 269 | dst->rate_tokens = token; |
1da177e4 LT |
270 | return rc; |
271 | } | |
272 | ||
b34a95ee PE |
273 | static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
274 | int type, int code) | |
1da177e4 LT |
275 | { |
276 | struct dst_entry *dst = &rt->u.dst; | |
277 | int rc = 1; | |
278 | ||
279 | if (type > NR_ICMP_TYPES) | |
280 | goto out; | |
281 | ||
282 | /* Don't limit PMTU discovery. */ | |
283 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
284 | goto out; | |
285 | ||
286 | /* No rate limit on loopback */ | |
287 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 288 | goto out; |
1da177e4 LT |
289 | |
290 | /* Limit if icmp type is enabled in ratemask. */ | |
b34a95ee PE |
291 | if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) |
292 | rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit); | |
1da177e4 LT |
293 | out: |
294 | return rc; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
299 | */ | |
96793b48 | 300 | void icmp_out_count(unsigned char type) |
1da177e4 | 301 | { |
96793b48 DS |
302 | ICMPMSGOUT_INC_STATS(type); |
303 | ICMP_INC_STATS(ICMP_MIB_OUTMSGS); | |
1da177e4 LT |
304 | } |
305 | ||
306 | /* | |
307 | * Checksum each fragment, and on the first include the headers and final | |
308 | * checksum. | |
309 | */ | |
310 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
311 | struct sk_buff *skb) | |
312 | { | |
313 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 314 | __wsum csum; |
1da177e4 LT |
315 | |
316 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
317 | icmp_param->offset + offset, | |
318 | to, len, 0); | |
319 | ||
320 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
321 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
322 | nf_ct_attach(skb, icmp_param->skb); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
327 | struct ipcm_cookie *ipc, struct rtable *rt) | |
328 | { | |
1e3cf683 | 329 | struct sock *sk; |
1da177e4 LT |
330 | struct sk_buff *skb; |
331 | ||
c346dca1 | 332 | sk = icmp_sk(dev_net(rt->u.dst.dev)); |
1e3cf683 | 333 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
334 | icmp_param->data_len+icmp_param->head_len, |
335 | icmp_param->head_len, | |
336 | ipc, rt, MSG_DONTWAIT) < 0) | |
1e3cf683 DL |
337 | ip_flush_pending_frames(sk); |
338 | else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { | |
88c7664f | 339 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 340 | __wsum csum = 0; |
1da177e4 LT |
341 | struct sk_buff *skb1; |
342 | ||
1e3cf683 | 343 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
344 | csum = csum_add(csum, skb1->csum); |
345 | } | |
346 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
347 | (char *)icmph, | |
348 | icmp_param->head_len, csum); | |
349 | icmph->checksum = csum_fold(csum); | |
350 | skb->ip_summed = CHECKSUM_NONE; | |
1e3cf683 | 351 | ip_push_pending_frames(sk); |
1da177e4 LT |
352 | } |
353 | } | |
354 | ||
355 | /* | |
356 | * Driving logic for building and sending ICMP messages. | |
357 | */ | |
358 | ||
359 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
360 | { | |
1da177e4 | 361 | struct ipcm_cookie ipc; |
ee6b9673 | 362 | struct rtable *rt = skb->rtable; |
c346dca1 | 363 | struct net *net = dev_net(rt->u.dst.dev); |
4a6ad7a1 DL |
364 | struct sock *sk = icmp_sk(net); |
365 | struct inet_sock *inet = inet_sk(sk); | |
3ca3c68e | 366 | __be32 daddr; |
1da177e4 LT |
367 | |
368 | if (ip_options_echo(&icmp_param->replyopts, skb)) | |
f00c401b | 369 | return; |
1da177e4 | 370 | |
405666db | 371 | if (icmp_xmit_lock(sk)) |
1da177e4 LT |
372 | return; |
373 | ||
374 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 375 | |
eddc9ec5 | 376 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
377 | daddr = ipc.addr = rt->rt_src; |
378 | ipc.opt = NULL; | |
379 | if (icmp_param->replyopts.optlen) { | |
380 | ipc.opt = &icmp_param->replyopts; | |
381 | if (ipc.opt->srr) | |
382 | daddr = icmp_param->replyopts.faddr; | |
383 | } | |
384 | { | |
385 | struct flowi fl = { .nl_u = { .ip4_u = | |
386 | { .daddr = daddr, | |
387 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 388 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 | 389 | .proto = IPPROTO_ICMP }; |
beb8d13b | 390 | security_skb_classify_flow(skb, &fl); |
4a6ad7a1 | 391 | if (ip_route_output_key(net, &rt, &fl)) |
1da177e4 LT |
392 | goto out_unlock; |
393 | } | |
b34a95ee | 394 | if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, |
1da177e4 LT |
395 | icmp_param->data.icmph.code)) |
396 | icmp_push_reply(icmp_param, &ipc, rt); | |
397 | ip_rt_put(rt); | |
398 | out_unlock: | |
405666db | 399 | icmp_xmit_unlock(sk); |
1da177e4 LT |
400 | } |
401 | ||
402 | ||
403 | /* | |
404 | * Send an ICMP message in response to a situation | |
405 | * | |
406 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
407 | * MAY send more (we do). | |
408 | * MUST NOT change this header information. | |
409 | * MUST NOT reply to a multicast/broadcast IP address. | |
410 | * MUST NOT reply to a multicast/broadcast MAC address. | |
411 | * MUST reply to only the first fragment. | |
412 | */ | |
413 | ||
e4883014 | 414 | void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
1da177e4 LT |
415 | { |
416 | struct iphdr *iph; | |
417 | int room; | |
418 | struct icmp_bxm icmp_param; | |
ee6b9673 | 419 | struct rtable *rt = skb_in->rtable; |
1da177e4 | 420 | struct ipcm_cookie ipc; |
a61ced5d | 421 | __be32 saddr; |
1da177e4 | 422 | u8 tos; |
dde1bc0e | 423 | struct net *net; |
4a6ad7a1 | 424 | struct sock *sk; |
1da177e4 LT |
425 | |
426 | if (!rt) | |
427 | goto out; | |
c346dca1 | 428 | net = dev_net(rt->u.dst.dev); |
4a6ad7a1 | 429 | sk = icmp_sk(net); |
1da177e4 LT |
430 | |
431 | /* | |
432 | * Find the original header. It is expected to be valid, of course. | |
433 | * Check this, icmp_send is called from the most obscure devices | |
434 | * sometimes. | |
435 | */ | |
eddc9ec5 | 436 | iph = ip_hdr(skb_in); |
1da177e4 | 437 | |
27a884dc ACM |
438 | if ((u8 *)iph < skb_in->head || |
439 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
440 | goto out; |
441 | ||
442 | /* | |
443 | * No replies to physical multicast/broadcast | |
444 | */ | |
445 | if (skb_in->pkt_type != PACKET_HOST) | |
446 | goto out; | |
447 | ||
448 | /* | |
449 | * Now check at the protocol level | |
450 | */ | |
451 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
452 | goto out; | |
453 | ||
454 | /* | |
455 | * Only reply to fragment 0. We byte re-order the constant | |
456 | * mask for efficiency. | |
457 | */ | |
458 | if (iph->frag_off & htons(IP_OFFSET)) | |
459 | goto out; | |
460 | ||
461 | /* | |
462 | * If we send an ICMP error to an ICMP error a mess would result.. | |
463 | */ | |
464 | if (icmp_pointers[type].error) { | |
465 | /* | |
466 | * We are an error, check if we are replying to an | |
467 | * ICMP error | |
468 | */ | |
469 | if (iph->protocol == IPPROTO_ICMP) { | |
470 | u8 _inner_type, *itp; | |
471 | ||
472 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 473 | skb_network_header(skb_in) + |
1da177e4 LT |
474 | (iph->ihl << 2) + |
475 | offsetof(struct icmphdr, | |
476 | type) - | |
477 | skb_in->data, | |
478 | sizeof(_inner_type), | |
479 | &_inner_type); | |
480 | if (itp == NULL) | |
481 | goto out; | |
482 | ||
483 | /* | |
484 | * Assume any unknown ICMP type is an error. This | |
485 | * isn't specified by the RFC, but think about it.. | |
486 | */ | |
487 | if (*itp > NR_ICMP_TYPES || | |
488 | icmp_pointers[*itp].error) | |
489 | goto out; | |
490 | } | |
491 | } | |
492 | ||
405666db | 493 | if (icmp_xmit_lock(sk)) |
1da177e4 LT |
494 | return; |
495 | ||
496 | /* | |
497 | * Construct source address and options. | |
498 | */ | |
499 | ||
500 | saddr = iph->daddr; | |
1c2fb7f9 | 501 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
502 | struct net_device *dev = NULL; |
503 | ||
a24022e1 | 504 | if (rt->fl.iif && |
b34a95ee | 505 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) |
dde1bc0e | 506 | dev = dev_get_by_index(net, rt->fl.iif); |
6e1d9103 PM |
507 | |
508 | if (dev) { | |
509 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); | |
510 | dev_put(dev); | |
511 | } else | |
1c2fb7f9 S |
512 | saddr = 0; |
513 | } | |
1da177e4 LT |
514 | |
515 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
516 | IPTOS_PREC_INTERNETCONTROL) : | |
517 | iph->tos; | |
518 | ||
519 | if (ip_options_echo(&icmp_param.replyopts, skb_in)) | |
fa60cf7f | 520 | goto out_unlock; |
1da177e4 LT |
521 | |
522 | ||
523 | /* | |
524 | * Prepare data for ICMP header. | |
525 | */ | |
526 | ||
527 | icmp_param.data.icmph.type = type; | |
528 | icmp_param.data.icmph.code = code; | |
529 | icmp_param.data.icmph.un.gateway = info; | |
530 | icmp_param.data.icmph.checksum = 0; | |
531 | icmp_param.skb = skb_in; | |
d56f90a7 | 532 | icmp_param.offset = skb_network_offset(skb_in); |
405666db | 533 | inet_sk(sk)->tos = tos; |
1da177e4 LT |
534 | ipc.addr = iph->saddr; |
535 | ipc.opt = &icmp_param.replyopts; | |
536 | ||
537 | { | |
538 | struct flowi fl = { | |
539 | .nl_u = { | |
540 | .ip4_u = { | |
541 | .daddr = icmp_param.replyopts.srr ? | |
542 | icmp_param.replyopts.faddr : | |
543 | iph->saddr, | |
544 | .saddr = saddr, | |
545 | .tos = RT_TOS(tos) | |
546 | } | |
547 | }, | |
548 | .proto = IPPROTO_ICMP, | |
549 | .uli_u = { | |
550 | .icmpt = { | |
551 | .type = type, | |
552 | .code = code | |
553 | } | |
554 | } | |
555 | }; | |
8b7817f3 HX |
556 | int err; |
557 | struct rtable *rt2; | |
558 | ||
beb8d13b | 559 | security_skb_classify_flow(skb_in, &fl); |
dde1bc0e | 560 | if (__ip_route_output_key(net, &rt, &fl)) |
8b7817f3 HX |
561 | goto out_unlock; |
562 | ||
563 | /* No need to clone since we're just using its address. */ | |
564 | rt2 = rt; | |
565 | ||
566 | err = xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0); | |
567 | switch (err) { | |
568 | case 0: | |
569 | if (rt != rt2) | |
570 | goto route_done; | |
571 | break; | |
572 | case -EPERM: | |
573 | rt = NULL; | |
574 | break; | |
575 | default: | |
576 | goto out_unlock; | |
577 | } | |
578 | ||
579 | if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET)) | |
7c0ecc4c | 580 | goto ende; |
8b7817f3 | 581 | |
dde1bc0e DL |
582 | if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) |
583 | err = __ip_route_output_key(net, &rt2, &fl); | |
8b7817f3 HX |
584 | else { |
585 | struct flowi fl2 = {}; | |
586 | struct dst_entry *odst; | |
587 | ||
588 | fl2.fl4_dst = fl.fl4_src; | |
dde1bc0e | 589 | if (ip_route_output_key(net, &rt2, &fl2)) |
7c0ecc4c | 590 | goto ende; |
8b7817f3 HX |
591 | |
592 | /* Ugh! */ | |
593 | odst = skb_in->dst; | |
594 | err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src, | |
595 | RT_TOS(tos), rt2->u.dst.dev); | |
596 | ||
597 | dst_release(&rt2->u.dst); | |
ee6b9673 | 598 | rt2 = skb_in->rtable; |
8b7817f3 HX |
599 | skb_in->dst = odst; |
600 | } | |
601 | ||
602 | if (err) | |
7c0ecc4c | 603 | goto ende; |
8b7817f3 HX |
604 | |
605 | err = xfrm_lookup((struct dst_entry **)&rt2, &fl, NULL, | |
606 | XFRM_LOOKUP_ICMP); | |
607 | if (err == -ENOENT) { | |
608 | if (!rt) | |
609 | goto out_unlock; | |
610 | goto route_done; | |
611 | } | |
612 | ||
613 | dst_release(&rt->u.dst); | |
614 | rt = rt2; | |
615 | ||
616 | if (err) | |
1da177e4 LT |
617 | goto out_unlock; |
618 | } | |
619 | ||
8b7817f3 | 620 | route_done: |
b34a95ee | 621 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
622 | goto ende; |
623 | ||
624 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
625 | ||
626 | room = dst_mtu(&rt->u.dst); | |
627 | if (room > 576) | |
628 | room = 576; | |
629 | room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen; | |
630 | room -= sizeof(struct icmphdr); | |
631 | ||
632 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
633 | if (icmp_param.data_len > room) | |
634 | icmp_param.data_len = room; | |
635 | icmp_param.head_len = sizeof(struct icmphdr); | |
636 | ||
637 | icmp_push_reply(&icmp_param, &ipc, rt); | |
638 | ende: | |
639 | ip_rt_put(rt); | |
640 | out_unlock: | |
405666db | 641 | icmp_xmit_unlock(sk); |
1da177e4 LT |
642 | out:; |
643 | } | |
644 | ||
645 | ||
646 | /* | |
647 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
648 | */ | |
649 | ||
650 | static void icmp_unreach(struct sk_buff *skb) | |
651 | { | |
652 | struct iphdr *iph; | |
653 | struct icmphdr *icmph; | |
654 | int hash, protocol; | |
655 | struct net_protocol *ipprot; | |
1da177e4 | 656 | u32 info = 0; |
dde1bc0e DL |
657 | struct net *net; |
658 | ||
c346dca1 | 659 | net = dev_net(skb->dst->dev); |
1da177e4 LT |
660 | |
661 | /* | |
662 | * Incomplete header ? | |
663 | * Only checks for the IP header, there should be an | |
664 | * additional check for longer headers in upper levels. | |
665 | */ | |
666 | ||
667 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
668 | goto out_err; | |
669 | ||
88c7664f | 670 | icmph = icmp_hdr(skb); |
1da177e4 LT |
671 | iph = (struct iphdr *)skb->data; |
672 | ||
673 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
674 | goto out_err; | |
675 | ||
676 | if (icmph->type == ICMP_DEST_UNREACH) { | |
677 | switch (icmph->code & 15) { | |
678 | case ICMP_NET_UNREACH: | |
679 | case ICMP_HOST_UNREACH: | |
680 | case ICMP_PROT_UNREACH: | |
681 | case ICMP_PORT_UNREACH: | |
682 | break; | |
683 | case ICMP_FRAG_NEEDED: | |
684 | if (ipv4_config.no_pmtu_disc) { | |
64ce2073 | 685 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: " |
1da177e4 LT |
686 | "fragmentation needed " |
687 | "and DF set.\n", | |
64ce2073 | 688 | NIPQUAD(iph->daddr)); |
1da177e4 | 689 | } else { |
dde1bc0e | 690 | info = ip_rt_frag_needed(net, iph, |
1da177e4 LT |
691 | ntohs(icmph->un.frag.mtu)); |
692 | if (!info) | |
693 | goto out; | |
694 | } | |
695 | break; | |
696 | case ICMP_SR_FAILED: | |
64ce2073 | 697 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: Source " |
1da177e4 | 698 | "Route Failed.\n", |
64ce2073 | 699 | NIPQUAD(iph->daddr)); |
1da177e4 LT |
700 | break; |
701 | default: | |
702 | break; | |
703 | } | |
704 | if (icmph->code > NR_ICMP_UNREACH) | |
705 | goto out; | |
706 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
707 | info = ntohl(icmph->un.gateway) >> 24; | |
708 | ||
709 | /* | |
710 | * Throw it at our lower layers | |
711 | * | |
712 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
713 | * header. | |
714 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
715 | * transport layer. | |
716 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
717 | * transport layer. | |
718 | */ | |
719 | ||
720 | /* | |
721 | * Check the other end isnt violating RFC 1122. Some routers send | |
722 | * bogus responses to broadcast frames. If you see this message | |
723 | * first check your netmask matches at both ends, if it does then | |
724 | * get the other vendor to fix their kit. | |
725 | */ | |
726 | ||
b34a95ee | 727 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 728 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 LT |
729 | if (net_ratelimit()) |
730 | printk(KERN_WARNING "%u.%u.%u.%u sent an invalid ICMP " | |
731 | "type %u, code %u " | |
732 | "error to a broadcast: %u.%u.%u.%u on %s\n", | |
eddc9ec5 | 733 | NIPQUAD(ip_hdr(skb)->saddr), |
1da177e4 LT |
734 | icmph->type, icmph->code, |
735 | NIPQUAD(iph->daddr), | |
736 | skb->dev->name); | |
737 | goto out; | |
738 | } | |
739 | ||
740 | /* Checkin full IP header plus 8 bytes of protocol to | |
741 | * avoid additional coding at protocol handlers. | |
742 | */ | |
743 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
744 | goto out; | |
745 | ||
746 | iph = (struct iphdr *)skb->data; | |
747 | protocol = iph->protocol; | |
748 | ||
749 | /* | |
750 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
751 | */ | |
7bc54c90 | 752 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 753 | |
1da177e4 | 754 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
755 | rcu_read_lock(); |
756 | ipprot = rcu_dereference(inet_protos[hash]); | |
757 | if (ipprot && ipprot->err_handler) | |
758 | ipprot->err_handler(skb, info); | |
759 | rcu_read_unlock(); | |
760 | ||
761 | out: | |
762 | return; | |
763 | out_err: | |
764 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
765 | goto out; | |
766 | } | |
767 | ||
768 | ||
769 | /* | |
770 | * Handle ICMP_REDIRECT. | |
771 | */ | |
772 | ||
773 | static void icmp_redirect(struct sk_buff *skb) | |
774 | { | |
775 | struct iphdr *iph; | |
1da177e4 LT |
776 | |
777 | if (skb->len < sizeof(struct iphdr)) | |
778 | goto out_err; | |
779 | ||
780 | /* | |
781 | * Get the copied header of the packet that caused the redirect | |
782 | */ | |
783 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
784 | goto out; | |
785 | ||
786 | iph = (struct iphdr *)skb->data; | |
1da177e4 | 787 | |
88c7664f | 788 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
789 | case ICMP_REDIR_NET: |
790 | case ICMP_REDIR_NETTOS: | |
791 | /* | |
792 | * As per RFC recommendations now handle it as a host redirect. | |
793 | */ | |
794 | case ICMP_REDIR_HOST: | |
795 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 796 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 797 | icmp_hdr(skb)->un.gateway, |
cef2685e | 798 | iph->saddr, skb->dev); |
1da177e4 | 799 | break; |
e905a9ed | 800 | } |
1da177e4 LT |
801 | out: |
802 | return; | |
803 | out_err: | |
804 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
805 | goto out; | |
806 | } | |
807 | ||
808 | /* | |
809 | * Handle ICMP_ECHO ("ping") requests. | |
810 | * | |
811 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
812 | * requests. | |
813 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
814 | * included in the reply. | |
815 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
816 | * echo requests, MUST have default=NOT. | |
817 | * See also WRT handling of options once they are done and working. | |
818 | */ | |
819 | ||
820 | static void icmp_echo(struct sk_buff *skb) | |
821 | { | |
b34a95ee PE |
822 | struct net *net; |
823 | ||
789e41e6 | 824 | net = dev_net(skb->dst->dev); |
b34a95ee | 825 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
826 | struct icmp_bxm icmp_param; |
827 | ||
88c7664f | 828 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
829 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
830 | icmp_param.skb = skb; | |
831 | icmp_param.offset = 0; | |
832 | icmp_param.data_len = skb->len; | |
833 | icmp_param.head_len = sizeof(struct icmphdr); | |
834 | icmp_reply(&icmp_param, skb); | |
835 | } | |
836 | } | |
837 | ||
838 | /* | |
839 | * Handle ICMP Timestamp requests. | |
840 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
841 | * SHOULD be in the kernel for minimum random latency. | |
842 | * MUST be accurate to a few minutes. | |
843 | * MUST be updated at least at 15Hz. | |
844 | */ | |
845 | static void icmp_timestamp(struct sk_buff *skb) | |
846 | { | |
847 | struct timeval tv; | |
848 | struct icmp_bxm icmp_param; | |
849 | /* | |
850 | * Too short. | |
851 | */ | |
852 | if (skb->len < 4) | |
853 | goto out_err; | |
854 | ||
855 | /* | |
856 | * Fill in the current time as ms since midnight UT: | |
857 | */ | |
858 | do_gettimeofday(&tv); | |
859 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * 1000 + | |
860 | tv.tv_usec / 1000); | |
861 | icmp_param.data.times[2] = icmp_param.data.times[1]; | |
862 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
863 | BUG(); | |
88c7664f | 864 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
865 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
866 | icmp_param.data.icmph.code = 0; | |
867 | icmp_param.skb = skb; | |
868 | icmp_param.offset = 0; | |
869 | icmp_param.data_len = 0; | |
870 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
871 | icmp_reply(&icmp_param, skb); | |
872 | out: | |
873 | return; | |
874 | out_err: | |
875 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
876 | goto out; | |
877 | } | |
878 | ||
879 | ||
880 | /* | |
881 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
882 | * | |
883 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
884 | * ADDRESS_MASK requests if it's been configured as an address mask | |
885 | * agent. Receiving a request doesn't constitute implicit permission to | |
886 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
887 | * a way to turn the functionality on and off. Another one for sysctl(), | |
888 | * I guess. -- MS | |
889 | * | |
890 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
891 | * A router SHOULD have switch turning it on/off. | |
892 | * This switch MUST be ON by default. | |
893 | * | |
894 | * Gratuitous replies, zero-source replies are not implemented, | |
895 | * that complies with RFC. DO NOT implement them!!! All the idea | |
896 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
897 | * The problem is that it is not uncommon to have several prefixes | |
898 | * on one physical interface. Moreover, addrmask agent can even be | |
899 | * not aware of existing another prefixes. | |
900 | * If source is zero, addrmask agent cannot choose correct prefix. | |
901 | * Gratuitous mask announcements suffer from the same problem. | |
902 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
903 | * that is pretty silly. --ANK | |
904 | * | |
905 | * All these rules are so bizarre, that I removed kernel addrmask | |
906 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
907 | * any case. --ANK | |
908 | * | |
909 | * Furthermore you can do it with a usermode address agent program | |
910 | * anyway... | |
911 | */ | |
912 | ||
913 | static void icmp_address(struct sk_buff *skb) | |
914 | { | |
915 | #if 0 | |
916 | if (net_ratelimit()) | |
917 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
918 | #endif | |
919 | } | |
920 | ||
921 | /* | |
922 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
923 | * loudly if an inconsistency is found. | |
924 | */ | |
925 | ||
926 | static void icmp_address_reply(struct sk_buff *skb) | |
927 | { | |
ee6b9673 | 928 | struct rtable *rt = skb->rtable; |
1da177e4 LT |
929 | struct net_device *dev = skb->dev; |
930 | struct in_device *in_dev; | |
931 | struct in_ifaddr *ifa; | |
932 | ||
933 | if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC)) | |
934 | goto out; | |
935 | ||
936 | in_dev = in_dev_get(dev); | |
937 | if (!in_dev) | |
938 | goto out; | |
939 | rcu_read_lock(); | |
940 | if (in_dev->ifa_list && | |
941 | IN_DEV_LOG_MARTIANS(in_dev) && | |
942 | IN_DEV_FORWARD(in_dev)) { | |
a144ea4b | 943 | __be32 _mask, *mp; |
1da177e4 LT |
944 | |
945 | mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask); | |
09a62660 | 946 | BUG_ON(mp == NULL); |
1da177e4 LT |
947 | for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { |
948 | if (*mp == ifa->ifa_mask && | |
949 | inet_ifa_match(rt->rt_src, ifa)) | |
950 | break; | |
951 | } | |
952 | if (!ifa && net_ratelimit()) { | |
953 | printk(KERN_INFO "Wrong address mask %u.%u.%u.%u from " | |
954 | "%s/%u.%u.%u.%u\n", | |
955 | NIPQUAD(*mp), dev->name, NIPQUAD(rt->rt_src)); | |
956 | } | |
957 | } | |
958 | rcu_read_unlock(); | |
959 | in_dev_put(in_dev); | |
960 | out:; | |
961 | } | |
962 | ||
963 | static void icmp_discard(struct sk_buff *skb) | |
964 | { | |
965 | } | |
966 | ||
967 | /* | |
968 | * Deal with incoming ICMP packets. | |
969 | */ | |
970 | int icmp_rcv(struct sk_buff *skb) | |
971 | { | |
972 | struct icmphdr *icmph; | |
ee6b9673 | 973 | struct rtable *rt = skb->rtable; |
1da177e4 | 974 | |
aebcf82c | 975 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
8b7817f3 HX |
976 | int nh; |
977 | ||
aebcf82c HX |
978 | if (!(skb->sp && skb->sp->xvec[skb->sp->len - 1]->props.flags & |
979 | XFRM_STATE_ICMP)) | |
980 | goto drop; | |
981 | ||
8b7817f3 HX |
982 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
983 | goto drop; | |
984 | ||
985 | nh = skb_network_offset(skb); | |
986 | skb_set_network_header(skb, sizeof(*icmph)); | |
987 | ||
988 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
989 | goto drop; | |
990 | ||
991 | skb_set_network_header(skb, nh); | |
992 | } | |
993 | ||
1da177e4 LT |
994 | ICMP_INC_STATS_BH(ICMP_MIB_INMSGS); |
995 | ||
996 | switch (skb->ip_summed) { | |
84fa7933 | 997 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 998 | if (!csum_fold(skb->csum)) |
1da177e4 | 999 | break; |
fb286bb2 | 1000 | /* fall through */ |
1da177e4 | 1001 | case CHECKSUM_NONE: |
fb286bb2 HX |
1002 | skb->csum = 0; |
1003 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 1004 | goto error; |
1da177e4 LT |
1005 | } |
1006 | ||
8cf22943 HX |
1007 | if (!pskb_pull(skb, sizeof(*icmph))) |
1008 | goto error; | |
1da177e4 | 1009 | |
88c7664f | 1010 | icmph = icmp_hdr(skb); |
1da177e4 | 1011 | |
96793b48 | 1012 | ICMPMSGIN_INC_STATS_BH(icmph->type); |
1da177e4 LT |
1013 | /* |
1014 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
1015 | * | |
1016 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1017 | * discarded. | |
1018 | */ | |
1019 | if (icmph->type > NR_ICMP_TYPES) | |
1020 | goto error; | |
1021 | ||
1022 | ||
1023 | /* | |
1024 | * Parse the ICMP message | |
1025 | */ | |
1026 | ||
e905a9ed | 1027 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
b34a95ee PE |
1028 | struct net *net; |
1029 | ||
789e41e6 | 1030 | net = dev_net(rt->u.dst.dev); |
1da177e4 LT |
1031 | /* |
1032 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1033 | * silently ignored (we let user decide with a sysctl). | |
1034 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1035 | * discarded if to broadcast/multicast. | |
1036 | */ | |
4c866aa7 AK |
1037 | if ((icmph->type == ICMP_ECHO || |
1038 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1039 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1040 | goto error; |
1041 | } | |
1042 | if (icmph->type != ICMP_ECHO && | |
1043 | icmph->type != ICMP_TIMESTAMP && | |
1044 | icmph->type != ICMP_ADDRESS && | |
1045 | icmph->type != ICMP_ADDRESSREPLY) { | |
1046 | goto error; | |
e905a9ed | 1047 | } |
1da177e4 LT |
1048 | } |
1049 | ||
1da177e4 LT |
1050 | icmp_pointers[icmph->type].handler(skb); |
1051 | ||
1052 | drop: | |
1053 | kfree_skb(skb); | |
1054 | return 0; | |
1055 | error: | |
1056 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
1057 | goto drop; | |
1058 | } | |
1059 | ||
1060 | /* | |
1061 | * This table is the definition of how we handle ICMP. | |
1062 | */ | |
9b5b5cff | 1063 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1064 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1065 | .handler = icmp_discard, |
1066 | }, | |
1067 | [1] = { | |
1da177e4 LT |
1068 | .handler = icmp_discard, |
1069 | .error = 1, | |
1070 | }, | |
1071 | [2] = { | |
1da177e4 LT |
1072 | .handler = icmp_discard, |
1073 | .error = 1, | |
1074 | }, | |
1075 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1076 | .handler = icmp_unreach, |
1077 | .error = 1, | |
1078 | }, | |
1079 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1080 | .handler = icmp_unreach, |
1081 | .error = 1, | |
1082 | }, | |
1083 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1084 | .handler = icmp_redirect, |
1085 | .error = 1, | |
1086 | }, | |
1087 | [6] = { | |
1da177e4 LT |
1088 | .handler = icmp_discard, |
1089 | .error = 1, | |
1090 | }, | |
1091 | [7] = { | |
1da177e4 LT |
1092 | .handler = icmp_discard, |
1093 | .error = 1, | |
1094 | }, | |
1095 | [ICMP_ECHO] = { | |
1da177e4 LT |
1096 | .handler = icmp_echo, |
1097 | }, | |
1098 | [9] = { | |
1da177e4 LT |
1099 | .handler = icmp_discard, |
1100 | .error = 1, | |
1101 | }, | |
1102 | [10] = { | |
1da177e4 LT |
1103 | .handler = icmp_discard, |
1104 | .error = 1, | |
1105 | }, | |
1106 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1107 | .handler = icmp_unreach, |
1108 | .error = 1, | |
1109 | }, | |
1110 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1111 | .handler = icmp_unreach, |
1112 | .error = 1, | |
1113 | }, | |
1114 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1115 | .handler = icmp_timestamp, |
1116 | }, | |
1117 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1118 | .handler = icmp_discard, |
1119 | }, | |
1120 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1121 | .handler = icmp_discard, |
1122 | }, | |
e905a9ed | 1123 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1124 | .handler = icmp_discard, |
1125 | }, | |
1126 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1127 | .handler = icmp_address, |
1128 | }, | |
1129 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1130 | .handler = icmp_address_reply, |
1131 | }, | |
1132 | }; | |
1133 | ||
4a6ad7a1 | 1134 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1135 | { |
1da177e4 LT |
1136 | int i; |
1137 | ||
5c8cafd6 | 1138 | for_each_possible_cpu(i) |
4a6ad7a1 DL |
1139 | sk_release_kernel(net->ipv4.icmp_sk[i]); |
1140 | kfree(net->ipv4.icmp_sk); | |
1141 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1142 | } |
1da177e4 | 1143 | |
4a6ad7a1 | 1144 | int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1145 | { |
a5710d65 DL |
1146 | int i, err; |
1147 | ||
4a6ad7a1 DL |
1148 | net->ipv4.icmp_sk = |
1149 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1150 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1151 | return -ENOMEM; |
1152 | ||
a5710d65 | 1153 | for_each_possible_cpu(i) { |
1e3cf683 DL |
1154 | struct sock *sk; |
1155 | struct socket *sock; | |
1156 | struct inet_sock *inet; | |
1da177e4 | 1157 | |
1e3cf683 | 1158 | err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP, &sock); |
1da177e4 | 1159 | if (err < 0) |
a5710d65 | 1160 | goto fail; |
1da177e4 | 1161 | |
4a6ad7a1 DL |
1162 | net->ipv4.icmp_sk[i] = sk = sock->sk; |
1163 | sk_change_net(sk, net); | |
5c8cafd6 | 1164 | |
1e3cf683 | 1165 | sk->sk_allocation = GFP_ATOMIC; |
1da177e4 LT |
1166 | |
1167 | /* Enough space for 2 64K ICMP packets, including | |
1168 | * sk_buff struct overhead. | |
1169 | */ | |
1e3cf683 | 1170 | sk->sk_sndbuf = |
1da177e4 LT |
1171 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1172 | ||
1e3cf683 | 1173 | inet = inet_sk(sk); |
1da177e4 LT |
1174 | inet->uc_ttl = -1; |
1175 | inet->pmtudisc = IP_PMTUDISC_DONT; | |
1176 | ||
1177 | /* Unhash it so that IP input processing does not even | |
1178 | * see it, we do not wish this socket to see incoming | |
1179 | * packets. | |
1180 | */ | |
1e3cf683 | 1181 | sk->sk_prot->unhash(sk); |
1da177e4 | 1182 | } |
a24022e1 PE |
1183 | |
1184 | /* Control parameters for ECHO replies. */ | |
1185 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1186 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1187 | ||
1188 | /* Control parameter - ignore bogus broadcast responses? */ | |
1189 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1190 | ||
1191 | /* | |
1192 | * Configurable global rate limit. | |
1193 | * | |
1194 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1195 | * bucket ratemask defines which icmp types are ratelimited by | |
1196 | * setting it's bit position. | |
1197 | * | |
1198 | * default: | |
1199 | * dest unreachable (3), source quench (4), | |
1200 | * time exceeded (11), parameter problem (12) | |
1201 | */ | |
1202 | ||
1203 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1204 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1205 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1206 | ||
a5710d65 DL |
1207 | return 0; |
1208 | ||
1209 | fail: | |
1d1c8d13 DL |
1210 | for_each_possible_cpu(i) |
1211 | sk_release_kernel(net->ipv4.icmp_sk[i]); | |
1212 | kfree(net->ipv4.icmp_sk); | |
a5710d65 | 1213 | return err; |
1da177e4 LT |
1214 | } |
1215 | ||
4a6ad7a1 DL |
1216 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1217 | .init = icmp_sk_init, | |
1218 | .exit = icmp_sk_exit, | |
1219 | }; | |
1220 | ||
1221 | int __init icmp_init(void) | |
1222 | { | |
1223 | return register_pernet_device(&icmp_sk_ops); | |
1224 | } | |
1225 | ||
1da177e4 LT |
1226 | EXPORT_SYMBOL(icmp_err_convert); |
1227 | EXPORT_SYMBOL(icmp_send); | |
1228 | EXPORT_SYMBOL(icmp_statistics); | |
1229 | EXPORT_SYMBOL(xrlim_allow); |