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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> | |
5a0e3ad6 | 77 | #include <linux/slab.h> |
1da177e4 LT |
78 | #include <net/snmp.h> |
79 | #include <net/ip.h> | |
80 | #include <net/route.h> | |
81 | #include <net/protocol.h> | |
82 | #include <net/icmp.h> | |
83 | #include <net/tcp.h> | |
84 | #include <net/udp.h> | |
85 | #include <net/raw.h> | |
86 | #include <linux/skbuff.h> | |
87 | #include <net/sock.h> | |
88 | #include <linux/errno.h> | |
89 | #include <linux/timer.h> | |
90 | #include <linux/init.h> | |
91 | #include <asm/system.h> | |
92 | #include <asm/uaccess.h> | |
93 | #include <net/checksum.h> | |
8b7817f3 | 94 | #include <net/xfrm.h> |
c1e9894d | 95 | #include <net/inet_common.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; | |
f6d8bd05 | 111 | struct ip_options_data replyopts; |
1da177e4 LT |
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 | ||
e754834e | 117 | const struct icmp_err icmp_err_convert[] = { |
1da177e4 LT |
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 | }; | |
4bc2f18b | 183 | EXPORT_SYMBOL(icmp_err_convert); |
1da177e4 | 184 | |
1da177e4 LT |
185 | /* |
186 | * ICMP control array. This specifies what to do with each ICMP. | |
187 | */ | |
188 | ||
189 | struct icmp_control { | |
1da177e4 LT |
190 | void (*handler)(struct sk_buff *skb); |
191 | short error; /* This ICMP is classed as an error message */ | |
192 | }; | |
193 | ||
9b5b5cff | 194 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; |
1da177e4 LT |
195 | |
196 | /* | |
197 | * The ICMP socket(s). This is the most convenient way to flow control | |
198 | * our ICMP output as well as maintain a clean interface throughout | |
199 | * all layers. All Socketless IP sends will soon be gone. | |
200 | * | |
201 | * On SMP we have one ICMP socket per-cpu. | |
202 | */ | |
4a6ad7a1 DL |
203 | static struct sock *icmp_sk(struct net *net) |
204 | { | |
205 | return net->ipv4.icmp_sk[smp_processor_id()]; | |
206 | } | |
1da177e4 | 207 | |
fdc0bde9 | 208 | static inline struct sock *icmp_xmit_lock(struct net *net) |
1da177e4 | 209 | { |
fdc0bde9 DL |
210 | struct sock *sk; |
211 | ||
1da177e4 LT |
212 | local_bh_disable(); |
213 | ||
fdc0bde9 DL |
214 | sk = icmp_sk(net); |
215 | ||
405666db | 216 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
217 | /* This can happen if the output path signals a |
218 | * dst_link_failure() for an outgoing ICMP packet. | |
219 | */ | |
220 | local_bh_enable(); | |
fdc0bde9 | 221 | return NULL; |
1da177e4 | 222 | } |
fdc0bde9 | 223 | return sk; |
1da177e4 LT |
224 | } |
225 | ||
405666db | 226 | static inline void icmp_xmit_unlock(struct sock *sk) |
1da177e4 | 227 | { |
405666db | 228 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
229 | } |
230 | ||
231 | /* | |
232 | * Send an ICMP frame. | |
233 | */ | |
234 | ||
92d86829 | 235 | static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
b34a95ee | 236 | int type, int code) |
1da177e4 | 237 | { |
d8d1f30b | 238 | struct dst_entry *dst = &rt->dst; |
92d86829 | 239 | bool rc = true; |
1da177e4 LT |
240 | |
241 | if (type > NR_ICMP_TYPES) | |
242 | goto out; | |
243 | ||
244 | /* Don't limit PMTU discovery. */ | |
245 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
246 | goto out; | |
247 | ||
248 | /* No rate limit on loopback */ | |
249 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 250 | goto out; |
1da177e4 LT |
251 | |
252 | /* Limit if icmp type is enabled in ratemask. */ | |
92d86829 DM |
253 | if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) { |
254 | if (!rt->peer) | |
255 | rt_bind_peer(rt, 1); | |
256 | rc = inet_peer_xrlim_allow(rt->peer, | |
257 | net->ipv4.sysctl_icmp_ratelimit); | |
258 | } | |
1da177e4 LT |
259 | out: |
260 | return rc; | |
261 | } | |
262 | ||
263 | /* | |
264 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
265 | */ | |
0388b004 | 266 | void icmp_out_count(struct net *net, unsigned char type) |
1da177e4 | 267 | { |
903fc196 | 268 | ICMPMSGOUT_INC_STATS(net, type); |
75c939bb | 269 | ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); |
1da177e4 LT |
270 | } |
271 | ||
272 | /* | |
273 | * Checksum each fragment, and on the first include the headers and final | |
274 | * checksum. | |
275 | */ | |
276 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
277 | struct sk_buff *skb) | |
278 | { | |
279 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 280 | __wsum csum; |
1da177e4 LT |
281 | |
282 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
283 | icmp_param->offset + offset, | |
284 | to, len, 0); | |
285 | ||
286 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
287 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
288 | nf_ct_attach(skb, icmp_param->skb); | |
289 | return 0; | |
290 | } | |
291 | ||
292 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
2e77d89b | 293 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 294 | { |
1e3cf683 | 295 | struct sock *sk; |
1da177e4 LT |
296 | struct sk_buff *skb; |
297 | ||
d8d1f30b | 298 | sk = icmp_sk(dev_net((*rt)->dst.dev)); |
1e3cf683 | 299 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
300 | icmp_param->data_len+icmp_param->head_len, |
301 | icmp_param->head_len, | |
1f8438a8 ED |
302 | ipc, rt, MSG_DONTWAIT) < 0) { |
303 | ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS); | |
1e3cf683 | 304 | ip_flush_pending_frames(sk); |
1f8438a8 | 305 | } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
88c7664f | 306 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 307 | __wsum csum = 0; |
1da177e4 LT |
308 | struct sk_buff *skb1; |
309 | ||
1e3cf683 | 310 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
311 | csum = csum_add(csum, skb1->csum); |
312 | } | |
313 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
314 | (char *)icmph, | |
315 | icmp_param->head_len, csum); | |
316 | icmph->checksum = csum_fold(csum); | |
317 | skb->ip_summed = CHECKSUM_NONE; | |
1e3cf683 | 318 | ip_push_pending_frames(sk); |
1da177e4 LT |
319 | } |
320 | } | |
321 | ||
322 | /* | |
323 | * Driving logic for building and sending ICMP messages. | |
324 | */ | |
325 | ||
326 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
327 | { | |
1da177e4 | 328 | struct ipcm_cookie ipc; |
511c3f92 | 329 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 330 | struct net *net = dev_net(rt->dst.dev); |
fdc0bde9 DL |
331 | struct sock *sk; |
332 | struct inet_sock *inet; | |
3ca3c68e | 333 | __be32 daddr; |
1da177e4 | 334 | |
f6d8bd05 | 335 | if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb)) |
f00c401b | 336 | return; |
1da177e4 | 337 | |
fdc0bde9 DL |
338 | sk = icmp_xmit_lock(net); |
339 | if (sk == NULL) | |
1da177e4 | 340 | return; |
fdc0bde9 | 341 | inet = inet_sk(sk); |
1da177e4 LT |
342 | |
343 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 344 | |
eddc9ec5 | 345 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
346 | daddr = ipc.addr = rt->rt_src; |
347 | ipc.opt = NULL; | |
2244d07b | 348 | ipc.tx_flags = 0; |
f6d8bd05 ED |
349 | if (icmp_param->replyopts.opt.opt.optlen) { |
350 | ipc.opt = &icmp_param->replyopts.opt; | |
351 | if (ipc.opt->opt.srr) | |
352 | daddr = icmp_param->replyopts.opt.opt.faddr; | |
1da177e4 LT |
353 | } |
354 | { | |
9d6ec938 DM |
355 | struct flowi4 fl4 = { |
356 | .daddr = daddr, | |
357 | .saddr = rt->rt_spec_dst, | |
358 | .flowi4_tos = RT_TOS(ip_hdr(skb)->tos), | |
359 | .flowi4_proto = IPPROTO_ICMP, | |
1d28f42c | 360 | }; |
9d6ec938 DM |
361 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); |
362 | rt = ip_route_output_key(net, &fl4); | |
b23dd4fe | 363 | if (IS_ERR(rt)) |
1da177e4 LT |
364 | goto out_unlock; |
365 | } | |
b34a95ee | 366 | if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, |
1da177e4 | 367 | icmp_param->data.icmph.code)) |
2e77d89b | 368 | icmp_push_reply(icmp_param, &ipc, &rt); |
1da177e4 LT |
369 | ip_rt_put(rt); |
370 | out_unlock: | |
405666db | 371 | icmp_xmit_unlock(sk); |
1da177e4 LT |
372 | } |
373 | ||
f6d460cf | 374 | static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in, |
b71d1d42 | 375 | const struct iphdr *iph, |
f6d460cf DM |
376 | __be32 saddr, u8 tos, |
377 | int type, int code, | |
378 | struct icmp_bxm *param) | |
379 | { | |
9d6ec938 | 380 | struct flowi4 fl4 = { |
f6d8bd05 ED |
381 | .daddr = (param->replyopts.opt.opt.srr ? |
382 | param->replyopts.opt.opt.faddr : iph->saddr), | |
9d6ec938 DM |
383 | .saddr = saddr, |
384 | .flowi4_tos = RT_TOS(tos), | |
385 | .flowi4_proto = IPPROTO_ICMP, | |
9cce96df DM |
386 | .fl4_icmp_type = type, |
387 | .fl4_icmp_code = code, | |
f6d460cf DM |
388 | }; |
389 | struct rtable *rt, *rt2; | |
390 | int err; | |
391 | ||
9d6ec938 DM |
392 | security_skb_classify_flow(skb_in, flowi4_to_flowi(&fl4)); |
393 | rt = __ip_route_output_key(net, &fl4); | |
b23dd4fe DM |
394 | if (IS_ERR(rt)) |
395 | return rt; | |
f6d460cf DM |
396 | |
397 | /* No need to clone since we're just using its address. */ | |
398 | rt2 = rt; | |
399 | ||
9d6ec938 DM |
400 | if (!fl4.saddr) |
401 | fl4.saddr = rt->rt_src; | |
f6d460cf | 402 | |
9d6ec938 DM |
403 | rt = (struct rtable *) xfrm_lookup(net, &rt->dst, |
404 | flowi4_to_flowi(&fl4), NULL, 0); | |
452edd59 | 405 | if (!IS_ERR(rt)) { |
f6d460cf DM |
406 | if (rt != rt2) |
407 | return rt; | |
452edd59 | 408 | } else if (PTR_ERR(rt) == -EPERM) { |
f6d460cf | 409 | rt = NULL; |
452edd59 DM |
410 | } else |
411 | return rt; | |
f6d460cf | 412 | |
9d6ec938 | 413 | err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4), AF_INET); |
f6d460cf DM |
414 | if (err) |
415 | goto relookup_failed; | |
416 | ||
9d6ec938 DM |
417 | if (inet_addr_type(net, fl4.saddr) == RTN_LOCAL) { |
418 | rt2 = __ip_route_output_key(net, &fl4); | |
b23dd4fe DM |
419 | if (IS_ERR(rt2)) |
420 | err = PTR_ERR(rt2); | |
f6d460cf | 421 | } else { |
9d6ec938 | 422 | struct flowi4 fl4_2 = {}; |
f6d460cf DM |
423 | unsigned long orefdst; |
424 | ||
9d6ec938 DM |
425 | fl4_2.daddr = fl4.saddr; |
426 | rt2 = ip_route_output_key(net, &fl4_2); | |
b23dd4fe DM |
427 | if (IS_ERR(rt2)) { |
428 | err = PTR_ERR(rt2); | |
f6d460cf | 429 | goto relookup_failed; |
b23dd4fe | 430 | } |
f6d460cf DM |
431 | /* Ugh! */ |
432 | orefdst = skb_in->_skb_refdst; /* save old refdst */ | |
9d6ec938 | 433 | err = ip_route_input(skb_in, fl4.daddr, fl4.saddr, |
f6d460cf DM |
434 | RT_TOS(tos), rt2->dst.dev); |
435 | ||
436 | dst_release(&rt2->dst); | |
437 | rt2 = skb_rtable(skb_in); | |
438 | skb_in->_skb_refdst = orefdst; /* restore old refdst */ | |
439 | } | |
440 | ||
441 | if (err) | |
442 | goto relookup_failed; | |
443 | ||
9d6ec938 DM |
444 | rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, |
445 | flowi4_to_flowi(&fl4), NULL, | |
446 | XFRM_LOOKUP_ICMP); | |
452edd59 | 447 | if (!IS_ERR(rt2)) { |
f6d460cf DM |
448 | dst_release(&rt->dst); |
449 | rt = rt2; | |
452edd59 DM |
450 | } else if (PTR_ERR(rt2) == -EPERM) { |
451 | if (rt) | |
452 | dst_release(&rt->dst); | |
453 | return rt2; | |
454 | } else { | |
455 | err = PTR_ERR(rt2); | |
456 | goto relookup_failed; | |
f6d460cf | 457 | } |
f6d460cf DM |
458 | return rt; |
459 | ||
460 | relookup_failed: | |
461 | if (rt) | |
462 | return rt; | |
463 | return ERR_PTR(err); | |
464 | } | |
1da177e4 LT |
465 | |
466 | /* | |
467 | * Send an ICMP message in response to a situation | |
468 | * | |
469 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
470 | * MAY send more (we do). | |
471 | * MUST NOT change this header information. | |
472 | * MUST NOT reply to a multicast/broadcast IP address. | |
473 | * MUST NOT reply to a multicast/broadcast MAC address. | |
474 | * MUST reply to only the first fragment. | |
475 | */ | |
476 | ||
e4883014 | 477 | void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
1da177e4 LT |
478 | { |
479 | struct iphdr *iph; | |
480 | int room; | |
481 | struct icmp_bxm icmp_param; | |
511c3f92 | 482 | struct rtable *rt = skb_rtable(skb_in); |
1da177e4 | 483 | struct ipcm_cookie ipc; |
a61ced5d | 484 | __be32 saddr; |
1da177e4 | 485 | u8 tos; |
dde1bc0e | 486 | struct net *net; |
4a6ad7a1 | 487 | struct sock *sk; |
1da177e4 LT |
488 | |
489 | if (!rt) | |
490 | goto out; | |
d8d1f30b | 491 | net = dev_net(rt->dst.dev); |
1da177e4 LT |
492 | |
493 | /* | |
494 | * Find the original header. It is expected to be valid, of course. | |
495 | * Check this, icmp_send is called from the most obscure devices | |
496 | * sometimes. | |
497 | */ | |
eddc9ec5 | 498 | iph = ip_hdr(skb_in); |
1da177e4 | 499 | |
27a884dc ACM |
500 | if ((u8 *)iph < skb_in->head || |
501 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
502 | goto out; |
503 | ||
504 | /* | |
505 | * No replies to physical multicast/broadcast | |
506 | */ | |
507 | if (skb_in->pkt_type != PACKET_HOST) | |
508 | goto out; | |
509 | ||
510 | /* | |
511 | * Now check at the protocol level | |
512 | */ | |
513 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
514 | goto out; | |
515 | ||
516 | /* | |
517 | * Only reply to fragment 0. We byte re-order the constant | |
518 | * mask for efficiency. | |
519 | */ | |
520 | if (iph->frag_off & htons(IP_OFFSET)) | |
521 | goto out; | |
522 | ||
523 | /* | |
524 | * If we send an ICMP error to an ICMP error a mess would result.. | |
525 | */ | |
526 | if (icmp_pointers[type].error) { | |
527 | /* | |
528 | * We are an error, check if we are replying to an | |
529 | * ICMP error | |
530 | */ | |
531 | if (iph->protocol == IPPROTO_ICMP) { | |
532 | u8 _inner_type, *itp; | |
533 | ||
534 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 535 | skb_network_header(skb_in) + |
1da177e4 LT |
536 | (iph->ihl << 2) + |
537 | offsetof(struct icmphdr, | |
538 | type) - | |
539 | skb_in->data, | |
540 | sizeof(_inner_type), | |
541 | &_inner_type); | |
542 | if (itp == NULL) | |
543 | goto out; | |
544 | ||
545 | /* | |
546 | * Assume any unknown ICMP type is an error. This | |
547 | * isn't specified by the RFC, but think about it.. | |
548 | */ | |
549 | if (*itp > NR_ICMP_TYPES || | |
550 | icmp_pointers[*itp].error) | |
551 | goto out; | |
552 | } | |
553 | } | |
554 | ||
fdc0bde9 DL |
555 | sk = icmp_xmit_lock(net); |
556 | if (sk == NULL) | |
1da177e4 LT |
557 | return; |
558 | ||
559 | /* | |
560 | * Construct source address and options. | |
561 | */ | |
562 | ||
563 | saddr = iph->daddr; | |
1c2fb7f9 | 564 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
565 | struct net_device *dev = NULL; |
566 | ||
685c7944 | 567 | rcu_read_lock(); |
c7537967 DM |
568 | if (rt_is_input_route(rt) && |
569 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) | |
5e2b61f7 | 570 | dev = dev_get_by_index_rcu(net, rt->rt_iif); |
6e1d9103 | 571 | |
685c7944 | 572 | if (dev) |
6e1d9103 | 573 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
685c7944 | 574 | else |
1c2fb7f9 | 575 | saddr = 0; |
685c7944 | 576 | rcu_read_unlock(); |
1c2fb7f9 | 577 | } |
1da177e4 LT |
578 | |
579 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
580 | IPTOS_PREC_INTERNETCONTROL) : | |
581 | iph->tos; | |
582 | ||
f6d8bd05 | 583 | if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in)) |
fa60cf7f | 584 | goto out_unlock; |
1da177e4 LT |
585 | |
586 | ||
587 | /* | |
588 | * Prepare data for ICMP header. | |
589 | */ | |
590 | ||
591 | icmp_param.data.icmph.type = type; | |
592 | icmp_param.data.icmph.code = code; | |
593 | icmp_param.data.icmph.un.gateway = info; | |
594 | icmp_param.data.icmph.checksum = 0; | |
595 | icmp_param.skb = skb_in; | |
d56f90a7 | 596 | icmp_param.offset = skb_network_offset(skb_in); |
405666db | 597 | inet_sk(sk)->tos = tos; |
1da177e4 | 598 | ipc.addr = iph->saddr; |
f6d8bd05 | 599 | ipc.opt = &icmp_param.replyopts.opt; |
2244d07b | 600 | ipc.tx_flags = 0; |
1da177e4 | 601 | |
f6d460cf DM |
602 | rt = icmp_route_lookup(net, skb_in, iph, saddr, tos, |
603 | type, code, &icmp_param); | |
604 | if (IS_ERR(rt)) | |
605 | goto out_unlock; | |
1da177e4 | 606 | |
b34a95ee | 607 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
608 | goto ende; |
609 | ||
610 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
611 | ||
d8d1f30b | 612 | room = dst_mtu(&rt->dst); |
1da177e4 LT |
613 | if (room > 576) |
614 | room = 576; | |
f6d8bd05 | 615 | room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; |
1da177e4 LT |
616 | room -= sizeof(struct icmphdr); |
617 | ||
618 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
619 | if (icmp_param.data_len > room) | |
620 | icmp_param.data_len = room; | |
621 | icmp_param.head_len = sizeof(struct icmphdr); | |
622 | ||
2e77d89b | 623 | icmp_push_reply(&icmp_param, &ipc, &rt); |
1da177e4 LT |
624 | ende: |
625 | ip_rt_put(rt); | |
626 | out_unlock: | |
405666db | 627 | icmp_xmit_unlock(sk); |
1da177e4 LT |
628 | out:; |
629 | } | |
4bc2f18b | 630 | EXPORT_SYMBOL(icmp_send); |
1da177e4 LT |
631 | |
632 | ||
633 | /* | |
634 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
635 | */ | |
636 | ||
637 | static void icmp_unreach(struct sk_buff *skb) | |
638 | { | |
b71d1d42 | 639 | const struct iphdr *iph; |
1da177e4 LT |
640 | struct icmphdr *icmph; |
641 | int hash, protocol; | |
32613090 | 642 | const struct net_protocol *ipprot; |
1da177e4 | 643 | u32 info = 0; |
dde1bc0e DL |
644 | struct net *net; |
645 | ||
adf30907 | 646 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
647 | |
648 | /* | |
649 | * Incomplete header ? | |
650 | * Only checks for the IP header, there should be an | |
651 | * additional check for longer headers in upper levels. | |
652 | */ | |
653 | ||
654 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
655 | goto out_err; | |
656 | ||
88c7664f | 657 | icmph = icmp_hdr(skb); |
b71d1d42 | 658 | iph = (const struct iphdr *)skb->data; |
1da177e4 LT |
659 | |
660 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
661 | goto out_err; | |
662 | ||
663 | if (icmph->type == ICMP_DEST_UNREACH) { | |
664 | switch (icmph->code & 15) { | |
665 | case ICMP_NET_UNREACH: | |
666 | case ICMP_HOST_UNREACH: | |
667 | case ICMP_PROT_UNREACH: | |
668 | case ICMP_PORT_UNREACH: | |
669 | break; | |
670 | case ICMP_FRAG_NEEDED: | |
671 | if (ipv4_config.no_pmtu_disc) { | |
673d57e7 HH |
672 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: fragmentation needed and DF set.\n", |
673 | &iph->daddr); | |
1da177e4 | 674 | } else { |
dde1bc0e | 675 | info = ip_rt_frag_needed(net, iph, |
0010e465 TT |
676 | ntohs(icmph->un.frag.mtu), |
677 | skb->dev); | |
1da177e4 LT |
678 | if (!info) |
679 | goto out; | |
680 | } | |
681 | break; | |
682 | case ICMP_SR_FAILED: | |
673d57e7 HH |
683 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: Source Route Failed.\n", |
684 | &iph->daddr); | |
1da177e4 LT |
685 | break; |
686 | default: | |
687 | break; | |
688 | } | |
689 | if (icmph->code > NR_ICMP_UNREACH) | |
690 | goto out; | |
691 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
692 | info = ntohl(icmph->un.gateway) >> 24; | |
693 | ||
694 | /* | |
695 | * Throw it at our lower layers | |
696 | * | |
697 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
698 | * header. | |
699 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
700 | * transport layer. | |
701 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
702 | * transport layer. | |
703 | */ | |
704 | ||
705 | /* | |
25985edc | 706 | * Check the other end isn't violating RFC 1122. Some routers send |
1da177e4 LT |
707 | * bogus responses to broadcast frames. If you see this message |
708 | * first check your netmask matches at both ends, if it does then | |
709 | * get the other vendor to fix their kit. | |
710 | */ | |
711 | ||
b34a95ee | 712 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 713 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 | 714 | if (net_ratelimit()) |
673d57e7 | 715 | printk(KERN_WARNING "%pI4 sent an invalid ICMP " |
1da177e4 | 716 | "type %u, code %u " |
673d57e7 HH |
717 | "error to a broadcast: %pI4 on %s\n", |
718 | &ip_hdr(skb)->saddr, | |
1da177e4 | 719 | icmph->type, icmph->code, |
673d57e7 | 720 | &iph->daddr, |
1da177e4 LT |
721 | skb->dev->name); |
722 | goto out; | |
723 | } | |
724 | ||
725 | /* Checkin full IP header plus 8 bytes of protocol to | |
726 | * avoid additional coding at protocol handlers. | |
727 | */ | |
728 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
729 | goto out; | |
730 | ||
b71d1d42 | 731 | iph = (const struct iphdr *)skb->data; |
1da177e4 LT |
732 | protocol = iph->protocol; |
733 | ||
734 | /* | |
735 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
736 | */ | |
7bc54c90 | 737 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 738 | |
1da177e4 | 739 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
740 | rcu_read_lock(); |
741 | ipprot = rcu_dereference(inet_protos[hash]); | |
742 | if (ipprot && ipprot->err_handler) | |
743 | ipprot->err_handler(skb, info); | |
744 | rcu_read_unlock(); | |
745 | ||
746 | out: | |
747 | return; | |
748 | out_err: | |
dcfc23ca | 749 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
750 | goto out; |
751 | } | |
752 | ||
753 | ||
754 | /* | |
755 | * Handle ICMP_REDIRECT. | |
756 | */ | |
757 | ||
758 | static void icmp_redirect(struct sk_buff *skb) | |
759 | { | |
b71d1d42 | 760 | const struct iphdr *iph; |
1da177e4 LT |
761 | |
762 | if (skb->len < sizeof(struct iphdr)) | |
763 | goto out_err; | |
764 | ||
765 | /* | |
766 | * Get the copied header of the packet that caused the redirect | |
767 | */ | |
768 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
769 | goto out; | |
770 | ||
b71d1d42 | 771 | iph = (const struct iphdr *)skb->data; |
1da177e4 | 772 | |
88c7664f | 773 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
774 | case ICMP_REDIR_NET: |
775 | case ICMP_REDIR_NETTOS: | |
776 | /* | |
777 | * As per RFC recommendations now handle it as a host redirect. | |
778 | */ | |
779 | case ICMP_REDIR_HOST: | |
780 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 781 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 782 | icmp_hdr(skb)->un.gateway, |
cef2685e | 783 | iph->saddr, skb->dev); |
1da177e4 | 784 | break; |
e905a9ed | 785 | } |
1da177e4 LT |
786 | out: |
787 | return; | |
788 | out_err: | |
dcfc23ca | 789 | ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
790 | goto out; |
791 | } | |
792 | ||
793 | /* | |
794 | * Handle ICMP_ECHO ("ping") requests. | |
795 | * | |
796 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
797 | * requests. | |
798 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
799 | * included in the reply. | |
800 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
801 | * echo requests, MUST have default=NOT. | |
802 | * See also WRT handling of options once they are done and working. | |
803 | */ | |
804 | ||
805 | static void icmp_echo(struct sk_buff *skb) | |
806 | { | |
b34a95ee PE |
807 | struct net *net; |
808 | ||
adf30907 | 809 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 810 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
811 | struct icmp_bxm icmp_param; |
812 | ||
88c7664f | 813 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
814 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
815 | icmp_param.skb = skb; | |
816 | icmp_param.offset = 0; | |
817 | icmp_param.data_len = skb->len; | |
818 | icmp_param.head_len = sizeof(struct icmphdr); | |
819 | icmp_reply(&icmp_param, skb); | |
820 | } | |
821 | } | |
822 | ||
823 | /* | |
824 | * Handle ICMP Timestamp requests. | |
825 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
826 | * SHOULD be in the kernel for minimum random latency. | |
827 | * MUST be accurate to a few minutes. | |
828 | * MUST be updated at least at 15Hz. | |
829 | */ | |
830 | static void icmp_timestamp(struct sk_buff *skb) | |
831 | { | |
f25c3d61 | 832 | struct timespec tv; |
1da177e4 LT |
833 | struct icmp_bxm icmp_param; |
834 | /* | |
835 | * Too short. | |
836 | */ | |
837 | if (skb->len < 4) | |
838 | goto out_err; | |
839 | ||
840 | /* | |
841 | * Fill in the current time as ms since midnight UT: | |
842 | */ | |
f25c3d61 YH |
843 | getnstimeofday(&tv); |
844 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + | |
845 | tv.tv_nsec / NSEC_PER_MSEC); | |
1da177e4 LT |
846 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
847 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
848 | BUG(); | |
88c7664f | 849 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
850 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
851 | icmp_param.data.icmph.code = 0; | |
852 | icmp_param.skb = skb; | |
853 | icmp_param.offset = 0; | |
854 | icmp_param.data_len = 0; | |
855 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
856 | icmp_reply(&icmp_param, skb); | |
857 | out: | |
858 | return; | |
859 | out_err: | |
adf30907 | 860 | ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
861 | goto out; |
862 | } | |
863 | ||
864 | ||
865 | /* | |
866 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
867 | * | |
868 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
869 | * ADDRESS_MASK requests if it's been configured as an address mask | |
870 | * agent. Receiving a request doesn't constitute implicit permission to | |
871 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
872 | * a way to turn the functionality on and off. Another one for sysctl(), | |
873 | * I guess. -- MS | |
874 | * | |
875 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
876 | * A router SHOULD have switch turning it on/off. | |
877 | * This switch MUST be ON by default. | |
878 | * | |
879 | * Gratuitous replies, zero-source replies are not implemented, | |
880 | * that complies with RFC. DO NOT implement them!!! All the idea | |
881 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
882 | * The problem is that it is not uncommon to have several prefixes | |
883 | * on one physical interface. Moreover, addrmask agent can even be | |
884 | * not aware of existing another prefixes. | |
885 | * If source is zero, addrmask agent cannot choose correct prefix. | |
886 | * Gratuitous mask announcements suffer from the same problem. | |
887 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
888 | * that is pretty silly. --ANK | |
889 | * | |
890 | * All these rules are so bizarre, that I removed kernel addrmask | |
891 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
892 | * any case. --ANK | |
893 | * | |
894 | * Furthermore you can do it with a usermode address agent program | |
895 | * anyway... | |
896 | */ | |
897 | ||
898 | static void icmp_address(struct sk_buff *skb) | |
899 | { | |
900 | #if 0 | |
901 | if (net_ratelimit()) | |
902 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
903 | #endif | |
904 | } | |
905 | ||
906 | /* | |
907 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
908 | * loudly if an inconsistency is found. | |
cfa087f6 | 909 | * called with rcu_read_lock() |
1da177e4 LT |
910 | */ |
911 | ||
912 | static void icmp_address_reply(struct sk_buff *skb) | |
913 | { | |
511c3f92 | 914 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
915 | struct net_device *dev = skb->dev; |
916 | struct in_device *in_dev; | |
917 | struct in_ifaddr *ifa; | |
918 | ||
919 | if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC)) | |
cfa087f6 | 920 | return; |
1da177e4 | 921 | |
cfa087f6 | 922 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 | 923 | if (!in_dev) |
cfa087f6 ED |
924 | return; |
925 | ||
1da177e4 LT |
926 | if (in_dev->ifa_list && |
927 | IN_DEV_LOG_MARTIANS(in_dev) && | |
928 | IN_DEV_FORWARD(in_dev)) { | |
a144ea4b | 929 | __be32 _mask, *mp; |
1da177e4 LT |
930 | |
931 | mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask); | |
09a62660 | 932 | BUG_ON(mp == NULL); |
1da177e4 LT |
933 | for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { |
934 | if (*mp == ifa->ifa_mask && | |
935 | inet_ifa_match(rt->rt_src, ifa)) | |
936 | break; | |
937 | } | |
938 | if (!ifa && net_ratelimit()) { | |
673d57e7 HH |
939 | printk(KERN_INFO "Wrong address mask %pI4 from %s/%pI4\n", |
940 | mp, dev->name, &rt->rt_src); | |
1da177e4 LT |
941 | } |
942 | } | |
1da177e4 LT |
943 | } |
944 | ||
945 | static void icmp_discard(struct sk_buff *skb) | |
946 | { | |
947 | } | |
948 | ||
949 | /* | |
950 | * Deal with incoming ICMP packets. | |
951 | */ | |
952 | int icmp_rcv(struct sk_buff *skb) | |
953 | { | |
954 | struct icmphdr *icmph; | |
511c3f92 | 955 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 956 | struct net *net = dev_net(rt->dst.dev); |
1da177e4 | 957 | |
aebcf82c | 958 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 959 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
960 | int nh; |
961 | ||
def8b4fa | 962 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
963 | XFRM_STATE_ICMP)) |
964 | goto drop; | |
965 | ||
8b7817f3 HX |
966 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
967 | goto drop; | |
968 | ||
969 | nh = skb_network_offset(skb); | |
970 | skb_set_network_header(skb, sizeof(*icmph)); | |
971 | ||
972 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
973 | goto drop; | |
974 | ||
975 | skb_set_network_header(skb, nh); | |
976 | } | |
977 | ||
dcfc23ca | 978 | ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS); |
1da177e4 LT |
979 | |
980 | switch (skb->ip_summed) { | |
84fa7933 | 981 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 982 | if (!csum_fold(skb->csum)) |
1da177e4 | 983 | break; |
fb286bb2 | 984 | /* fall through */ |
1da177e4 | 985 | case CHECKSUM_NONE: |
fb286bb2 HX |
986 | skb->csum = 0; |
987 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 988 | goto error; |
1da177e4 LT |
989 | } |
990 | ||
8cf22943 HX |
991 | if (!pskb_pull(skb, sizeof(*icmph))) |
992 | goto error; | |
1da177e4 | 993 | |
88c7664f | 994 | icmph = icmp_hdr(skb); |
1da177e4 | 995 | |
f66ac03d | 996 | ICMPMSGIN_INC_STATS_BH(net, icmph->type); |
1da177e4 LT |
997 | /* |
998 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
999 | * | |
1000 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1001 | * discarded. | |
1002 | */ | |
1003 | if (icmph->type > NR_ICMP_TYPES) | |
1004 | goto error; | |
1005 | ||
1006 | ||
1007 | /* | |
1008 | * Parse the ICMP message | |
1009 | */ | |
1010 | ||
e905a9ed | 1011 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1012 | /* |
1013 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1014 | * silently ignored (we let user decide with a sysctl). | |
1015 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1016 | * discarded if to broadcast/multicast. | |
1017 | */ | |
4c866aa7 AK |
1018 | if ((icmph->type == ICMP_ECHO || |
1019 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1020 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1021 | goto error; |
1022 | } | |
1023 | if (icmph->type != ICMP_ECHO && | |
1024 | icmph->type != ICMP_TIMESTAMP && | |
1025 | icmph->type != ICMP_ADDRESS && | |
1026 | icmph->type != ICMP_ADDRESSREPLY) { | |
1027 | goto error; | |
e905a9ed | 1028 | } |
1da177e4 LT |
1029 | } |
1030 | ||
1da177e4 LT |
1031 | icmp_pointers[icmph->type].handler(skb); |
1032 | ||
1033 | drop: | |
1034 | kfree_skb(skb); | |
1035 | return 0; | |
1036 | error: | |
dcfc23ca | 1037 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1038 | goto drop; |
1039 | } | |
1040 | ||
1041 | /* | |
1042 | * This table is the definition of how we handle ICMP. | |
1043 | */ | |
9b5b5cff | 1044 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1045 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1046 | .handler = icmp_discard, |
1047 | }, | |
1048 | [1] = { | |
1da177e4 LT |
1049 | .handler = icmp_discard, |
1050 | .error = 1, | |
1051 | }, | |
1052 | [2] = { | |
1da177e4 LT |
1053 | .handler = icmp_discard, |
1054 | .error = 1, | |
1055 | }, | |
1056 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1057 | .handler = icmp_unreach, |
1058 | .error = 1, | |
1059 | }, | |
1060 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1061 | .handler = icmp_unreach, |
1062 | .error = 1, | |
1063 | }, | |
1064 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1065 | .handler = icmp_redirect, |
1066 | .error = 1, | |
1067 | }, | |
1068 | [6] = { | |
1da177e4 LT |
1069 | .handler = icmp_discard, |
1070 | .error = 1, | |
1071 | }, | |
1072 | [7] = { | |
1da177e4 LT |
1073 | .handler = icmp_discard, |
1074 | .error = 1, | |
1075 | }, | |
1076 | [ICMP_ECHO] = { | |
1da177e4 LT |
1077 | .handler = icmp_echo, |
1078 | }, | |
1079 | [9] = { | |
1da177e4 LT |
1080 | .handler = icmp_discard, |
1081 | .error = 1, | |
1082 | }, | |
1083 | [10] = { | |
1da177e4 LT |
1084 | .handler = icmp_discard, |
1085 | .error = 1, | |
1086 | }, | |
1087 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1088 | .handler = icmp_unreach, |
1089 | .error = 1, | |
1090 | }, | |
1091 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1092 | .handler = icmp_unreach, |
1093 | .error = 1, | |
1094 | }, | |
1095 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1096 | .handler = icmp_timestamp, |
1097 | }, | |
1098 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1099 | .handler = icmp_discard, |
1100 | }, | |
1101 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1102 | .handler = icmp_discard, |
1103 | }, | |
e905a9ed | 1104 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1105 | .handler = icmp_discard, |
1106 | }, | |
1107 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1108 | .handler = icmp_address, |
1109 | }, | |
1110 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1111 | .handler = icmp_address_reply, |
1112 | }, | |
1113 | }; | |
1114 | ||
4a6ad7a1 | 1115 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1116 | { |
1da177e4 LT |
1117 | int i; |
1118 | ||
5c8cafd6 | 1119 | for_each_possible_cpu(i) |
c1e9894d | 1120 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
4a6ad7a1 DL |
1121 | kfree(net->ipv4.icmp_sk); |
1122 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1123 | } |
1da177e4 | 1124 | |
263173af | 1125 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1126 | { |
a5710d65 DL |
1127 | int i, err; |
1128 | ||
4a6ad7a1 DL |
1129 | net->ipv4.icmp_sk = |
1130 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1131 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1132 | return -ENOMEM; |
1133 | ||
a5710d65 | 1134 | for_each_possible_cpu(i) { |
1e3cf683 | 1135 | struct sock *sk; |
1da177e4 | 1136 | |
c1e9894d DL |
1137 | err = inet_ctl_sock_create(&sk, PF_INET, |
1138 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1139 | if (err < 0) |
a5710d65 | 1140 | goto fail; |
1da177e4 | 1141 | |
c1e9894d | 1142 | net->ipv4.icmp_sk[i] = sk; |
1da177e4 LT |
1143 | |
1144 | /* Enough space for 2 64K ICMP packets, including | |
1145 | * sk_buff struct overhead. | |
1146 | */ | |
1e3cf683 | 1147 | sk->sk_sndbuf = |
1da177e4 LT |
1148 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1149 | ||
b3a5b6cc ED |
1150 | /* |
1151 | * Speedup sock_wfree() | |
1152 | */ | |
1153 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
c1e9894d | 1154 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1155 | } |
a24022e1 PE |
1156 | |
1157 | /* Control parameters for ECHO replies. */ | |
1158 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1159 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1160 | ||
1161 | /* Control parameter - ignore bogus broadcast responses? */ | |
1162 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1163 | ||
1164 | /* | |
1165 | * Configurable global rate limit. | |
1166 | * | |
1167 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1168 | * bucket ratemask defines which icmp types are ratelimited by | |
1169 | * setting it's bit position. | |
1170 | * | |
1171 | * default: | |
1172 | * dest unreachable (3), source quench (4), | |
1173 | * time exceeded (11), parameter problem (12) | |
1174 | */ | |
1175 | ||
1176 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1177 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1178 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1179 | ||
a5710d65 DL |
1180 | return 0; |
1181 | ||
1182 | fail: | |
1d1c8d13 | 1183 | for_each_possible_cpu(i) |
c1e9894d | 1184 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
1d1c8d13 | 1185 | kfree(net->ipv4.icmp_sk); |
a5710d65 | 1186 | return err; |
1da177e4 LT |
1187 | } |
1188 | ||
4a6ad7a1 DL |
1189 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1190 | .init = icmp_sk_init, | |
1191 | .exit = icmp_sk_exit, | |
1192 | }; | |
1193 | ||
1194 | int __init icmp_init(void) | |
1195 | { | |
959d2726 | 1196 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 | 1197 | } |