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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NET3: Implementation of the ICMP protocol layer. | |
3 | * | |
113aa838 | 4 | * Alan Cox, <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 5 | * |
1da177e4 LT |
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 | * Some of the function names and the icmp unreach table for this | |
12 | * module were derived from [icmp.c 1.0.11 06/02/93] by | |
13 | * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting. | |
14 | * Other than that this module is a complete rewrite. | |
15 | * | |
16 | * Fixes: | |
17 | * Clemens Fruhwirth : introduce global icmp rate limiting | |
18 | * with icmp type masking ability instead | |
19 | * of broken per type icmp timeouts. | |
20 | * Mike Shaver : RFC1122 checks. | |
21 | * Alan Cox : Multicast ping reply as self. | |
22 | * Alan Cox : Fix atomicity lockup in ip_build_xmit | |
23 | * call. | |
24 | * Alan Cox : Added 216,128 byte paths to the MTU | |
25 | * code. | |
26 | * Martin Mares : RFC1812 checks. | |
27 | * Martin Mares : Can be configured to follow redirects | |
28 | * if acting as a router _without_ a | |
29 | * routing protocol (RFC 1812). | |
30 | * Martin Mares : Echo requests may be configured to | |
31 | * be ignored (RFC 1812). | |
32 | * Martin Mares : Limitation of ICMP error message | |
33 | * transmit rate (RFC 1812). | |
34 | * Martin Mares : TOS and Precedence set correctly | |
35 | * (RFC 1812). | |
36 | * Martin Mares : Now copying as much data from the | |
37 | * original packet as we can without | |
38 | * exceeding 576 bytes (RFC 1812). | |
39 | * Willy Konynenberg : Transparent proxying support. | |
40 | * Keith Owens : RFC1191 correction for 4.2BSD based | |
41 | * path MTU bug. | |
42 | * Thomas Quinot : ICMP Dest Unreach codes up to 15 are | |
43 | * valid (RFC 1812). | |
44 | * Andi Kleen : Check all packet lengths properly | |
45 | * and moved all kfree_skb() up to | |
46 | * icmp_rcv. | |
47 | * Andi Kleen : Move the rate limit bookkeeping | |
48 | * into the dest entry and use a token | |
49 | * bucket filter (thanks to ANK). Make | |
50 | * the rates sysctl configurable. | |
51 | * Yu Tianli : Fixed two ugly bugs in icmp_send | |
52 | * - IP option length was accounted wrongly | |
53 | * - ICMP header length was not accounted | |
54 | * at all. | |
55 | * Tristan Greaves : Added sysctl option to ignore bogus | |
56 | * broadcast responses from broken routers. | |
57 | * | |
58 | * To Fix: | |
59 | * | |
60 | * - Should use skb_pull() instead of all the manual checking. | |
61 | * This would also greatly simply some upper layer error handlers. --AK | |
62 | * | |
63 | */ | |
64 | ||
1da177e4 LT |
65 | #include <linux/module.h> |
66 | #include <linux/types.h> | |
67 | #include <linux/jiffies.h> | |
68 | #include <linux/kernel.h> | |
69 | #include <linux/fcntl.h> | |
70 | #include <linux/socket.h> | |
71 | #include <linux/in.h> | |
72 | #include <linux/inet.h> | |
14c85021 | 73 | #include <linux/inetdevice.h> |
1da177e4 LT |
74 | #include <linux/netdevice.h> |
75 | #include <linux/string.h> | |
76 | #include <linux/netfilter_ipv4.h> | |
77 | #include <net/snmp.h> | |
78 | #include <net/ip.h> | |
79 | #include <net/route.h> | |
80 | #include <net/protocol.h> | |
81 | #include <net/icmp.h> | |
82 | #include <net/tcp.h> | |
83 | #include <net/udp.h> | |
84 | #include <net/raw.h> | |
85 | #include <linux/skbuff.h> | |
86 | #include <net/sock.h> | |
87 | #include <linux/errno.h> | |
88 | #include <linux/timer.h> | |
89 | #include <linux/init.h> | |
90 | #include <asm/system.h> | |
91 | #include <asm/uaccess.h> | |
92 | #include <net/checksum.h> | |
8b7817f3 | 93 | #include <net/xfrm.h> |
c1e9894d | 94 | #include <net/inet_common.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; | |
110 | struct ip_options replyopts; | |
111 | unsigned char optbuf[40]; | |
112 | }; | |
113 | ||
1da177e4 LT |
114 | /* An array of errno for error messages from dest unreach. */ |
115 | /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */ | |
116 | ||
117 | struct icmp_err icmp_err_convert[] = { | |
118 | { | |
119 | .errno = ENETUNREACH, /* ICMP_NET_UNREACH */ | |
120 | .fatal = 0, | |
121 | }, | |
122 | { | |
123 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */ | |
124 | .fatal = 0, | |
125 | }, | |
126 | { | |
127 | .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */, | |
128 | .fatal = 1, | |
129 | }, | |
130 | { | |
131 | .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */ | |
132 | .fatal = 1, | |
133 | }, | |
134 | { | |
135 | .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */ | |
136 | .fatal = 0, | |
137 | }, | |
138 | { | |
139 | .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */ | |
140 | .fatal = 0, | |
141 | }, | |
142 | { | |
143 | .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */ | |
144 | .fatal = 1, | |
145 | }, | |
146 | { | |
147 | .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */ | |
148 | .fatal = 1, | |
149 | }, | |
150 | { | |
151 | .errno = ENONET, /* ICMP_HOST_ISOLATED */ | |
152 | .fatal = 1, | |
153 | }, | |
154 | { | |
155 | .errno = ENETUNREACH, /* ICMP_NET_ANO */ | |
156 | .fatal = 1, | |
157 | }, | |
158 | { | |
159 | .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */ | |
160 | .fatal = 1, | |
161 | }, | |
162 | { | |
163 | .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */ | |
164 | .fatal = 0, | |
165 | }, | |
166 | { | |
167 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */ | |
168 | .fatal = 0, | |
169 | }, | |
170 | { | |
171 | .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */ | |
172 | .fatal = 1, | |
173 | }, | |
174 | { | |
175 | .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */ | |
176 | .fatal = 1, | |
177 | }, | |
178 | { | |
179 | .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */ | |
180 | .fatal = 1, | |
181 | }, | |
182 | }; | |
183 | ||
1da177e4 LT |
184 | /* |
185 | * ICMP control array. This specifies what to do with each ICMP. | |
186 | */ | |
187 | ||
188 | struct icmp_control { | |
1da177e4 LT |
189 | void (*handler)(struct sk_buff *skb); |
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 | { | |
204 | return net->ipv4.icmp_sk[smp_processor_id()]; | |
205 | } | |
1da177e4 | 206 | |
fdc0bde9 | 207 | static inline struct sock *icmp_xmit_lock(struct net *net) |
1da177e4 | 208 | { |
fdc0bde9 DL |
209 | struct sock *sk; |
210 | ||
1da177e4 LT |
211 | local_bh_disable(); |
212 | ||
fdc0bde9 DL |
213 | sk = icmp_sk(net); |
214 | ||
405666db | 215 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
216 | /* This can happen if the output path signals a |
217 | * dst_link_failure() for an outgoing ICMP packet. | |
218 | */ | |
219 | local_bh_enable(); | |
fdc0bde9 | 220 | return NULL; |
1da177e4 | 221 | } |
fdc0bde9 | 222 | return sk; |
1da177e4 LT |
223 | } |
224 | ||
405666db | 225 | static inline void icmp_xmit_unlock(struct sock *sk) |
1da177e4 | 226 | { |
405666db | 227 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
228 | } |
229 | ||
230 | /* | |
231 | * Send an ICMP frame. | |
232 | */ | |
233 | ||
234 | /* | |
235 | * Check transmit rate limitation for given message. | |
236 | * The rate information is held in the destination cache now. | |
237 | * This function is generic and could be used for other purposes | |
238 | * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov. | |
239 | * | |
240 | * Note that the same dst_entry fields are modified by functions in | |
241 | * route.c too, but these work for packet destinations while xrlim_allow | |
242 | * works for icmp destinations. This means the rate limiting information | |
243 | * for one "ip object" is shared - and these ICMPs are twice limited: | |
244 | * by source and by destination. | |
245 | * | |
246 | * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate | |
247 | * SHOULD allow setting of rate limits | |
248 | * | |
249 | * Shared between ICMPv4 and ICMPv6. | |
250 | */ | |
251 | #define XRLIM_BURST_FACTOR 6 | |
252 | int xrlim_allow(struct dst_entry *dst, int timeout) | |
253 | { | |
69a73829 | 254 | unsigned long now, token = dst->rate_tokens; |
1da177e4 LT |
255 | int rc = 0; |
256 | ||
257 | now = jiffies; | |
69a73829 | 258 | token += now - dst->rate_last; |
1da177e4 | 259 | dst->rate_last = now; |
69a73829 ED |
260 | if (token > XRLIM_BURST_FACTOR * timeout) |
261 | token = XRLIM_BURST_FACTOR * timeout; | |
262 | if (token >= timeout) { | |
263 | token -= timeout; | |
1da177e4 LT |
264 | rc = 1; |
265 | } | |
69a73829 | 266 | dst->rate_tokens = token; |
1da177e4 LT |
267 | return rc; |
268 | } | |
269 | ||
b34a95ee PE |
270 | static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
271 | int type, int code) | |
1da177e4 LT |
272 | { |
273 | struct dst_entry *dst = &rt->u.dst; | |
274 | int rc = 1; | |
275 | ||
276 | if (type > NR_ICMP_TYPES) | |
277 | goto out; | |
278 | ||
279 | /* Don't limit PMTU discovery. */ | |
280 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
281 | goto out; | |
282 | ||
283 | /* No rate limit on loopback */ | |
284 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 285 | goto out; |
1da177e4 LT |
286 | |
287 | /* Limit if icmp type is enabled in ratemask. */ | |
b34a95ee PE |
288 | if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) |
289 | rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit); | |
1da177e4 LT |
290 | out: |
291 | return rc; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
296 | */ | |
0388b004 | 297 | void icmp_out_count(struct net *net, unsigned char type) |
1da177e4 | 298 | { |
903fc196 | 299 | ICMPMSGOUT_INC_STATS(net, type); |
75c939bb | 300 | ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); |
1da177e4 LT |
301 | } |
302 | ||
303 | /* | |
304 | * Checksum each fragment, and on the first include the headers and final | |
305 | * checksum. | |
306 | */ | |
307 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
308 | struct sk_buff *skb) | |
309 | { | |
310 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 311 | __wsum csum; |
1da177e4 LT |
312 | |
313 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
314 | icmp_param->offset + offset, | |
315 | to, len, 0); | |
316 | ||
317 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
318 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
319 | nf_ct_attach(skb, icmp_param->skb); | |
320 | return 0; | |
321 | } | |
322 | ||
323 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
2e77d89b | 324 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 325 | { |
1e3cf683 | 326 | struct sock *sk; |
1da177e4 LT |
327 | struct sk_buff *skb; |
328 | ||
2e77d89b | 329 | sk = icmp_sk(dev_net((*rt)->u.dst.dev)); |
1e3cf683 | 330 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
331 | icmp_param->data_len+icmp_param->head_len, |
332 | icmp_param->head_len, | |
333 | ipc, rt, MSG_DONTWAIT) < 0) | |
1e3cf683 DL |
334 | ip_flush_pending_frames(sk); |
335 | else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { | |
88c7664f | 336 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 337 | __wsum csum = 0; |
1da177e4 LT |
338 | struct sk_buff *skb1; |
339 | ||
1e3cf683 | 340 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
341 | csum = csum_add(csum, skb1->csum); |
342 | } | |
343 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
344 | (char *)icmph, | |
345 | icmp_param->head_len, csum); | |
346 | icmph->checksum = csum_fold(csum); | |
347 | skb->ip_summed = CHECKSUM_NONE; | |
1e3cf683 | 348 | ip_push_pending_frames(sk); |
1da177e4 LT |
349 | } |
350 | } | |
351 | ||
352 | /* | |
353 | * Driving logic for building and sending ICMP messages. | |
354 | */ | |
355 | ||
356 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
357 | { | |
1da177e4 | 358 | struct ipcm_cookie ipc; |
511c3f92 | 359 | struct rtable *rt = skb_rtable(skb); |
c346dca1 | 360 | struct net *net = dev_net(rt->u.dst.dev); |
fdc0bde9 DL |
361 | struct sock *sk; |
362 | struct inet_sock *inet; | |
3ca3c68e | 363 | __be32 daddr; |
1da177e4 LT |
364 | |
365 | if (ip_options_echo(&icmp_param->replyopts, skb)) | |
f00c401b | 366 | return; |
1da177e4 | 367 | |
fdc0bde9 DL |
368 | sk = icmp_xmit_lock(net); |
369 | if (sk == NULL) | |
1da177e4 | 370 | return; |
fdc0bde9 | 371 | inet = inet_sk(sk); |
1da177e4 LT |
372 | |
373 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 374 | |
eddc9ec5 | 375 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
376 | daddr = ipc.addr = rt->rt_src; |
377 | ipc.opt = NULL; | |
51f31cab | 378 | ipc.shtx.flags = 0; |
1da177e4 LT |
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 | 395 | icmp_param->data.icmph.code)) |
2e77d89b | 396 | icmp_push_reply(icmp_param, &ipc, &rt); |
1da177e4 LT |
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; | |
511c3f92 | 419 | struct rtable *rt = skb_rtable(skb_in); |
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); |
1da177e4 LT |
429 | |
430 | /* | |
431 | * Find the original header. It is expected to be valid, of course. | |
432 | * Check this, icmp_send is called from the most obscure devices | |
433 | * sometimes. | |
434 | */ | |
eddc9ec5 | 435 | iph = ip_hdr(skb_in); |
1da177e4 | 436 | |
27a884dc ACM |
437 | if ((u8 *)iph < skb_in->head || |
438 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
439 | goto out; |
440 | ||
441 | /* | |
442 | * No replies to physical multicast/broadcast | |
443 | */ | |
444 | if (skb_in->pkt_type != PACKET_HOST) | |
445 | goto out; | |
446 | ||
447 | /* | |
448 | * Now check at the protocol level | |
449 | */ | |
450 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
451 | goto out; | |
452 | ||
453 | /* | |
454 | * Only reply to fragment 0. We byte re-order the constant | |
455 | * mask for efficiency. | |
456 | */ | |
457 | if (iph->frag_off & htons(IP_OFFSET)) | |
458 | goto out; | |
459 | ||
460 | /* | |
461 | * If we send an ICMP error to an ICMP error a mess would result.. | |
462 | */ | |
463 | if (icmp_pointers[type].error) { | |
464 | /* | |
465 | * We are an error, check if we are replying to an | |
466 | * ICMP error | |
467 | */ | |
468 | if (iph->protocol == IPPROTO_ICMP) { | |
469 | u8 _inner_type, *itp; | |
470 | ||
471 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 472 | skb_network_header(skb_in) + |
1da177e4 LT |
473 | (iph->ihl << 2) + |
474 | offsetof(struct icmphdr, | |
475 | type) - | |
476 | skb_in->data, | |
477 | sizeof(_inner_type), | |
478 | &_inner_type); | |
479 | if (itp == NULL) | |
480 | goto out; | |
481 | ||
482 | /* | |
483 | * Assume any unknown ICMP type is an error. This | |
484 | * isn't specified by the RFC, but think about it.. | |
485 | */ | |
486 | if (*itp > NR_ICMP_TYPES || | |
487 | icmp_pointers[*itp].error) | |
488 | goto out; | |
489 | } | |
490 | } | |
491 | ||
fdc0bde9 DL |
492 | sk = icmp_xmit_lock(net); |
493 | if (sk == NULL) | |
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; | |
51f31cab | 536 | ipc.shtx.flags = 0; |
1da177e4 LT |
537 | |
538 | { | |
539 | struct flowi fl = { | |
540 | .nl_u = { | |
541 | .ip4_u = { | |
542 | .daddr = icmp_param.replyopts.srr ? | |
543 | icmp_param.replyopts.faddr : | |
544 | iph->saddr, | |
545 | .saddr = saddr, | |
546 | .tos = RT_TOS(tos) | |
547 | } | |
548 | }, | |
549 | .proto = IPPROTO_ICMP, | |
550 | .uli_u = { | |
551 | .icmpt = { | |
552 | .type = type, | |
553 | .code = code | |
554 | } | |
555 | } | |
556 | }; | |
8b7817f3 HX |
557 | int err; |
558 | struct rtable *rt2; | |
559 | ||
beb8d13b | 560 | security_skb_classify_flow(skb_in, &fl); |
dde1bc0e | 561 | if (__ip_route_output_key(net, &rt, &fl)) |
8b7817f3 HX |
562 | goto out_unlock; |
563 | ||
564 | /* No need to clone since we're just using its address. */ | |
565 | rt2 = rt; | |
566 | ||
52479b62 | 567 | err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0); |
8b7817f3 HX |
568 | switch (err) { |
569 | case 0: | |
570 | if (rt != rt2) | |
571 | goto route_done; | |
572 | break; | |
573 | case -EPERM: | |
574 | rt = NULL; | |
575 | break; | |
576 | default: | |
577 | goto out_unlock; | |
578 | } | |
579 | ||
580 | if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET)) | |
af268182 | 581 | goto relookup_failed; |
8b7817f3 | 582 | |
dde1bc0e DL |
583 | if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) |
584 | err = __ip_route_output_key(net, &rt2, &fl); | |
8b7817f3 HX |
585 | else { |
586 | struct flowi fl2 = {}; | |
587 | struct dst_entry *odst; | |
588 | ||
589 | fl2.fl4_dst = fl.fl4_src; | |
dde1bc0e | 590 | if (ip_route_output_key(net, &rt2, &fl2)) |
af268182 | 591 | goto relookup_failed; |
8b7817f3 HX |
592 | |
593 | /* Ugh! */ | |
adf30907 | 594 | odst = skb_dst(skb_in); |
8b7817f3 HX |
595 | err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src, |
596 | RT_TOS(tos), rt2->u.dst.dev); | |
597 | ||
598 | dst_release(&rt2->u.dst); | |
511c3f92 | 599 | rt2 = skb_rtable(skb_in); |
adf30907 | 600 | skb_dst_set(skb_in, odst); |
8b7817f3 HX |
601 | } |
602 | ||
603 | if (err) | |
af268182 | 604 | goto relookup_failed; |
8b7817f3 | 605 | |
52479b62 | 606 | err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL, |
8b7817f3 | 607 | XFRM_LOOKUP_ICMP); |
af268182 HX |
608 | switch (err) { |
609 | case 0: | |
610 | dst_release(&rt->u.dst); | |
611 | rt = rt2; | |
612 | break; | |
613 | case -EPERM: | |
614 | goto ende; | |
615 | default: | |
616 | relookup_failed: | |
8b7817f3 HX |
617 | if (!rt) |
618 | goto out_unlock; | |
af268182 | 619 | break; |
8b7817f3 | 620 | } |
1da177e4 LT |
621 | } |
622 | ||
8b7817f3 | 623 | route_done: |
b34a95ee | 624 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
625 | goto ende; |
626 | ||
627 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
628 | ||
629 | room = dst_mtu(&rt->u.dst); | |
630 | if (room > 576) | |
631 | room = 576; | |
632 | room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen; | |
633 | room -= sizeof(struct icmphdr); | |
634 | ||
635 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
636 | if (icmp_param.data_len > room) | |
637 | icmp_param.data_len = room; | |
638 | icmp_param.head_len = sizeof(struct icmphdr); | |
639 | ||
2e77d89b | 640 | icmp_push_reply(&icmp_param, &ipc, &rt); |
1da177e4 LT |
641 | ende: |
642 | ip_rt_put(rt); | |
643 | out_unlock: | |
405666db | 644 | icmp_xmit_unlock(sk); |
1da177e4 LT |
645 | out:; |
646 | } | |
647 | ||
648 | ||
649 | /* | |
650 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
651 | */ | |
652 | ||
653 | static void icmp_unreach(struct sk_buff *skb) | |
654 | { | |
655 | struct iphdr *iph; | |
656 | struct icmphdr *icmph; | |
657 | int hash, protocol; | |
658 | struct net_protocol *ipprot; | |
1da177e4 | 659 | u32 info = 0; |
dde1bc0e DL |
660 | struct net *net; |
661 | ||
adf30907 | 662 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
663 | |
664 | /* | |
665 | * Incomplete header ? | |
666 | * Only checks for the IP header, there should be an | |
667 | * additional check for longer headers in upper levels. | |
668 | */ | |
669 | ||
670 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
671 | goto out_err; | |
672 | ||
88c7664f | 673 | icmph = icmp_hdr(skb); |
1da177e4 LT |
674 | iph = (struct iphdr *)skb->data; |
675 | ||
676 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
677 | goto out_err; | |
678 | ||
679 | if (icmph->type == ICMP_DEST_UNREACH) { | |
680 | switch (icmph->code & 15) { | |
681 | case ICMP_NET_UNREACH: | |
682 | case ICMP_HOST_UNREACH: | |
683 | case ICMP_PROT_UNREACH: | |
684 | case ICMP_PORT_UNREACH: | |
685 | break; | |
686 | case ICMP_FRAG_NEEDED: | |
687 | if (ipv4_config.no_pmtu_disc) { | |
673d57e7 HH |
688 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: fragmentation needed and DF set.\n", |
689 | &iph->daddr); | |
1da177e4 | 690 | } else { |
dde1bc0e | 691 | info = ip_rt_frag_needed(net, iph, |
0010e465 TT |
692 | ntohs(icmph->un.frag.mtu), |
693 | skb->dev); | |
1da177e4 LT |
694 | if (!info) |
695 | goto out; | |
696 | } | |
697 | break; | |
698 | case ICMP_SR_FAILED: | |
673d57e7 HH |
699 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: Source Route Failed.\n", |
700 | &iph->daddr); | |
1da177e4 LT |
701 | break; |
702 | default: | |
703 | break; | |
704 | } | |
705 | if (icmph->code > NR_ICMP_UNREACH) | |
706 | goto out; | |
707 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
708 | info = ntohl(icmph->un.gateway) >> 24; | |
709 | ||
710 | /* | |
711 | * Throw it at our lower layers | |
712 | * | |
713 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
714 | * header. | |
715 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
716 | * transport layer. | |
717 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
718 | * transport layer. | |
719 | */ | |
720 | ||
721 | /* | |
722 | * Check the other end isnt violating RFC 1122. Some routers send | |
723 | * bogus responses to broadcast frames. If you see this message | |
724 | * first check your netmask matches at both ends, if it does then | |
725 | * get the other vendor to fix their kit. | |
726 | */ | |
727 | ||
b34a95ee | 728 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 729 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 | 730 | if (net_ratelimit()) |
673d57e7 | 731 | printk(KERN_WARNING "%pI4 sent an invalid ICMP " |
1da177e4 | 732 | "type %u, code %u " |
673d57e7 HH |
733 | "error to a broadcast: %pI4 on %s\n", |
734 | &ip_hdr(skb)->saddr, | |
1da177e4 | 735 | icmph->type, icmph->code, |
673d57e7 | 736 | &iph->daddr, |
1da177e4 LT |
737 | skb->dev->name); |
738 | goto out; | |
739 | } | |
740 | ||
741 | /* Checkin full IP header plus 8 bytes of protocol to | |
742 | * avoid additional coding at protocol handlers. | |
743 | */ | |
744 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
745 | goto out; | |
746 | ||
747 | iph = (struct iphdr *)skb->data; | |
748 | protocol = iph->protocol; | |
749 | ||
750 | /* | |
751 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
752 | */ | |
7bc54c90 | 753 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 754 | |
1da177e4 | 755 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
756 | rcu_read_lock(); |
757 | ipprot = rcu_dereference(inet_protos[hash]); | |
758 | if (ipprot && ipprot->err_handler) | |
759 | ipprot->err_handler(skb, info); | |
760 | rcu_read_unlock(); | |
761 | ||
762 | out: | |
763 | return; | |
764 | out_err: | |
dcfc23ca | 765 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
766 | goto out; |
767 | } | |
768 | ||
769 | ||
770 | /* | |
771 | * Handle ICMP_REDIRECT. | |
772 | */ | |
773 | ||
774 | static void icmp_redirect(struct sk_buff *skb) | |
775 | { | |
776 | struct iphdr *iph; | |
1da177e4 LT |
777 | |
778 | if (skb->len < sizeof(struct iphdr)) | |
779 | goto out_err; | |
780 | ||
781 | /* | |
782 | * Get the copied header of the packet that caused the redirect | |
783 | */ | |
784 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
785 | goto out; | |
786 | ||
787 | iph = (struct iphdr *)skb->data; | |
1da177e4 | 788 | |
88c7664f | 789 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
790 | case ICMP_REDIR_NET: |
791 | case ICMP_REDIR_NETTOS: | |
792 | /* | |
793 | * As per RFC recommendations now handle it as a host redirect. | |
794 | */ | |
795 | case ICMP_REDIR_HOST: | |
796 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 797 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 798 | icmp_hdr(skb)->un.gateway, |
cef2685e | 799 | iph->saddr, skb->dev); |
1da177e4 | 800 | break; |
e905a9ed | 801 | } |
1da177e4 LT |
802 | out: |
803 | return; | |
804 | out_err: | |
dcfc23ca | 805 | ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
806 | goto out; |
807 | } | |
808 | ||
809 | /* | |
810 | * Handle ICMP_ECHO ("ping") requests. | |
811 | * | |
812 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
813 | * requests. | |
814 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
815 | * included in the reply. | |
816 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
817 | * echo requests, MUST have default=NOT. | |
818 | * See also WRT handling of options once they are done and working. | |
819 | */ | |
820 | ||
821 | static void icmp_echo(struct sk_buff *skb) | |
822 | { | |
b34a95ee PE |
823 | struct net *net; |
824 | ||
adf30907 | 825 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 826 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
827 | struct icmp_bxm icmp_param; |
828 | ||
88c7664f | 829 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
830 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
831 | icmp_param.skb = skb; | |
832 | icmp_param.offset = 0; | |
833 | icmp_param.data_len = skb->len; | |
834 | icmp_param.head_len = sizeof(struct icmphdr); | |
835 | icmp_reply(&icmp_param, skb); | |
836 | } | |
837 | } | |
838 | ||
839 | /* | |
840 | * Handle ICMP Timestamp requests. | |
841 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
842 | * SHOULD be in the kernel for minimum random latency. | |
843 | * MUST be accurate to a few minutes. | |
844 | * MUST be updated at least at 15Hz. | |
845 | */ | |
846 | static void icmp_timestamp(struct sk_buff *skb) | |
847 | { | |
f25c3d61 | 848 | struct timespec tv; |
1da177e4 LT |
849 | struct icmp_bxm icmp_param; |
850 | /* | |
851 | * Too short. | |
852 | */ | |
853 | if (skb->len < 4) | |
854 | goto out_err; | |
855 | ||
856 | /* | |
857 | * Fill in the current time as ms since midnight UT: | |
858 | */ | |
f25c3d61 YH |
859 | getnstimeofday(&tv); |
860 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + | |
861 | tv.tv_nsec / NSEC_PER_MSEC); | |
1da177e4 LT |
862 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
863 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
864 | BUG(); | |
88c7664f | 865 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
866 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
867 | icmp_param.data.icmph.code = 0; | |
868 | icmp_param.skb = skb; | |
869 | icmp_param.offset = 0; | |
870 | icmp_param.data_len = 0; | |
871 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
872 | icmp_reply(&icmp_param, skb); | |
873 | out: | |
874 | return; | |
875 | out_err: | |
adf30907 | 876 | ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
877 | goto out; |
878 | } | |
879 | ||
880 | ||
881 | /* | |
882 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
883 | * | |
884 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
885 | * ADDRESS_MASK requests if it's been configured as an address mask | |
886 | * agent. Receiving a request doesn't constitute implicit permission to | |
887 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
888 | * a way to turn the functionality on and off. Another one for sysctl(), | |
889 | * I guess. -- MS | |
890 | * | |
891 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
892 | * A router SHOULD have switch turning it on/off. | |
893 | * This switch MUST be ON by default. | |
894 | * | |
895 | * Gratuitous replies, zero-source replies are not implemented, | |
896 | * that complies with RFC. DO NOT implement them!!! All the idea | |
897 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
898 | * The problem is that it is not uncommon to have several prefixes | |
899 | * on one physical interface. Moreover, addrmask agent can even be | |
900 | * not aware of existing another prefixes. | |
901 | * If source is zero, addrmask agent cannot choose correct prefix. | |
902 | * Gratuitous mask announcements suffer from the same problem. | |
903 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
904 | * that is pretty silly. --ANK | |
905 | * | |
906 | * All these rules are so bizarre, that I removed kernel addrmask | |
907 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
908 | * any case. --ANK | |
909 | * | |
910 | * Furthermore you can do it with a usermode address agent program | |
911 | * anyway... | |
912 | */ | |
913 | ||
914 | static void icmp_address(struct sk_buff *skb) | |
915 | { | |
916 | #if 0 | |
917 | if (net_ratelimit()) | |
918 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
919 | #endif | |
920 | } | |
921 | ||
922 | /* | |
923 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
924 | * loudly if an inconsistency is found. | |
925 | */ | |
926 | ||
927 | static void icmp_address_reply(struct sk_buff *skb) | |
928 | { | |
511c3f92 | 929 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
930 | struct net_device *dev = skb->dev; |
931 | struct in_device *in_dev; | |
932 | struct in_ifaddr *ifa; | |
933 | ||
934 | if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC)) | |
935 | goto out; | |
936 | ||
937 | in_dev = in_dev_get(dev); | |
938 | if (!in_dev) | |
939 | goto out; | |
940 | rcu_read_lock(); | |
941 | if (in_dev->ifa_list && | |
942 | IN_DEV_LOG_MARTIANS(in_dev) && | |
943 | IN_DEV_FORWARD(in_dev)) { | |
a144ea4b | 944 | __be32 _mask, *mp; |
1da177e4 LT |
945 | |
946 | mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask); | |
09a62660 | 947 | BUG_ON(mp == NULL); |
1da177e4 LT |
948 | for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { |
949 | if (*mp == ifa->ifa_mask && | |
950 | inet_ifa_match(rt->rt_src, ifa)) | |
951 | break; | |
952 | } | |
953 | if (!ifa && net_ratelimit()) { | |
673d57e7 HH |
954 | printk(KERN_INFO "Wrong address mask %pI4 from %s/%pI4\n", |
955 | mp, dev->name, &rt->rt_src); | |
1da177e4 LT |
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; | |
511c3f92 | 973 | struct rtable *rt = skb_rtable(skb); |
fd54d716 | 974 | struct net *net = dev_net(rt->u.dst.dev); |
1da177e4 | 975 | |
aebcf82c | 976 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 977 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
978 | int nh; |
979 | ||
def8b4fa | 980 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
981 | XFRM_STATE_ICMP)) |
982 | goto drop; | |
983 | ||
8b7817f3 HX |
984 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
985 | goto drop; | |
986 | ||
987 | nh = skb_network_offset(skb); | |
988 | skb_set_network_header(skb, sizeof(*icmph)); | |
989 | ||
990 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
991 | goto drop; | |
992 | ||
993 | skb_set_network_header(skb, nh); | |
994 | } | |
995 | ||
dcfc23ca | 996 | ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS); |
1da177e4 LT |
997 | |
998 | switch (skb->ip_summed) { | |
84fa7933 | 999 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 1000 | if (!csum_fold(skb->csum)) |
1da177e4 | 1001 | break; |
fb286bb2 | 1002 | /* fall through */ |
1da177e4 | 1003 | case CHECKSUM_NONE: |
fb286bb2 HX |
1004 | skb->csum = 0; |
1005 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 1006 | goto error; |
1da177e4 LT |
1007 | } |
1008 | ||
8cf22943 HX |
1009 | if (!pskb_pull(skb, sizeof(*icmph))) |
1010 | goto error; | |
1da177e4 | 1011 | |
88c7664f | 1012 | icmph = icmp_hdr(skb); |
1da177e4 | 1013 | |
f66ac03d | 1014 | ICMPMSGIN_INC_STATS_BH(net, icmph->type); |
1da177e4 LT |
1015 | /* |
1016 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
1017 | * | |
1018 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1019 | * discarded. | |
1020 | */ | |
1021 | if (icmph->type > NR_ICMP_TYPES) | |
1022 | goto error; | |
1023 | ||
1024 | ||
1025 | /* | |
1026 | * Parse the ICMP message | |
1027 | */ | |
1028 | ||
e905a9ed | 1029 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1030 | /* |
1031 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1032 | * silently ignored (we let user decide with a sysctl). | |
1033 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1034 | * discarded if to broadcast/multicast. | |
1035 | */ | |
4c866aa7 AK |
1036 | if ((icmph->type == ICMP_ECHO || |
1037 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1038 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1039 | goto error; |
1040 | } | |
1041 | if (icmph->type != ICMP_ECHO && | |
1042 | icmph->type != ICMP_TIMESTAMP && | |
1043 | icmph->type != ICMP_ADDRESS && | |
1044 | icmph->type != ICMP_ADDRESSREPLY) { | |
1045 | goto error; | |
e905a9ed | 1046 | } |
1da177e4 LT |
1047 | } |
1048 | ||
1da177e4 LT |
1049 | icmp_pointers[icmph->type].handler(skb); |
1050 | ||
1051 | drop: | |
1052 | kfree_skb(skb); | |
1053 | return 0; | |
1054 | error: | |
dcfc23ca | 1055 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1056 | goto drop; |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * This table is the definition of how we handle ICMP. | |
1061 | */ | |
9b5b5cff | 1062 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1063 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1064 | .handler = icmp_discard, |
1065 | }, | |
1066 | [1] = { | |
1da177e4 LT |
1067 | .handler = icmp_discard, |
1068 | .error = 1, | |
1069 | }, | |
1070 | [2] = { | |
1da177e4 LT |
1071 | .handler = icmp_discard, |
1072 | .error = 1, | |
1073 | }, | |
1074 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1075 | .handler = icmp_unreach, |
1076 | .error = 1, | |
1077 | }, | |
1078 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1079 | .handler = icmp_unreach, |
1080 | .error = 1, | |
1081 | }, | |
1082 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1083 | .handler = icmp_redirect, |
1084 | .error = 1, | |
1085 | }, | |
1086 | [6] = { | |
1da177e4 LT |
1087 | .handler = icmp_discard, |
1088 | .error = 1, | |
1089 | }, | |
1090 | [7] = { | |
1da177e4 LT |
1091 | .handler = icmp_discard, |
1092 | .error = 1, | |
1093 | }, | |
1094 | [ICMP_ECHO] = { | |
1da177e4 LT |
1095 | .handler = icmp_echo, |
1096 | }, | |
1097 | [9] = { | |
1da177e4 LT |
1098 | .handler = icmp_discard, |
1099 | .error = 1, | |
1100 | }, | |
1101 | [10] = { | |
1da177e4 LT |
1102 | .handler = icmp_discard, |
1103 | .error = 1, | |
1104 | }, | |
1105 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1106 | .handler = icmp_unreach, |
1107 | .error = 1, | |
1108 | }, | |
1109 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1110 | .handler = icmp_unreach, |
1111 | .error = 1, | |
1112 | }, | |
1113 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1114 | .handler = icmp_timestamp, |
1115 | }, | |
1116 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1117 | .handler = icmp_discard, |
1118 | }, | |
1119 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1120 | .handler = icmp_discard, |
1121 | }, | |
e905a9ed | 1122 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1123 | .handler = icmp_discard, |
1124 | }, | |
1125 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1126 | .handler = icmp_address, |
1127 | }, | |
1128 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1129 | .handler = icmp_address_reply, |
1130 | }, | |
1131 | }; | |
1132 | ||
4a6ad7a1 | 1133 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1134 | { |
1da177e4 LT |
1135 | int i; |
1136 | ||
5c8cafd6 | 1137 | for_each_possible_cpu(i) |
c1e9894d | 1138 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
4a6ad7a1 DL |
1139 | kfree(net->ipv4.icmp_sk); |
1140 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1141 | } |
1da177e4 | 1142 | |
263173af | 1143 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1144 | { |
a5710d65 DL |
1145 | int i, err; |
1146 | ||
4a6ad7a1 DL |
1147 | net->ipv4.icmp_sk = |
1148 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1149 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1150 | return -ENOMEM; |
1151 | ||
a5710d65 | 1152 | for_each_possible_cpu(i) { |
1e3cf683 | 1153 | struct sock *sk; |
1da177e4 | 1154 | |
c1e9894d DL |
1155 | err = inet_ctl_sock_create(&sk, PF_INET, |
1156 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1157 | if (err < 0) |
a5710d65 | 1158 | goto fail; |
1da177e4 | 1159 | |
c1e9894d | 1160 | net->ipv4.icmp_sk[i] = sk; |
1da177e4 LT |
1161 | |
1162 | /* Enough space for 2 64K ICMP packets, including | |
1163 | * sk_buff struct overhead. | |
1164 | */ | |
1e3cf683 | 1165 | sk->sk_sndbuf = |
1da177e4 LT |
1166 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1167 | ||
c1e9894d | 1168 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1169 | } |
a24022e1 PE |
1170 | |
1171 | /* Control parameters for ECHO replies. */ | |
1172 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1173 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1174 | ||
1175 | /* Control parameter - ignore bogus broadcast responses? */ | |
1176 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1177 | ||
1178 | /* | |
1179 | * Configurable global rate limit. | |
1180 | * | |
1181 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1182 | * bucket ratemask defines which icmp types are ratelimited by | |
1183 | * setting it's bit position. | |
1184 | * | |
1185 | * default: | |
1186 | * dest unreachable (3), source quench (4), | |
1187 | * time exceeded (11), parameter problem (12) | |
1188 | */ | |
1189 | ||
1190 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1191 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1192 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1193 | ||
a5710d65 DL |
1194 | return 0; |
1195 | ||
1196 | fail: | |
1d1c8d13 | 1197 | for_each_possible_cpu(i) |
c1e9894d | 1198 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
1d1c8d13 | 1199 | kfree(net->ipv4.icmp_sk); |
a5710d65 | 1200 | return err; |
1da177e4 LT |
1201 | } |
1202 | ||
4a6ad7a1 DL |
1203 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1204 | .init = icmp_sk_init, | |
1205 | .exit = icmp_sk_exit, | |
1206 | }; | |
1207 | ||
1208 | int __init icmp_init(void) | |
1209 | { | |
959d2726 | 1210 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 DL |
1211 | } |
1212 | ||
1da177e4 LT |
1213 | EXPORT_SYMBOL(icmp_err_convert); |
1214 | EXPORT_SYMBOL(icmp_send); | |
1da177e4 | 1215 | EXPORT_SYMBOL(xrlim_allow); |