Commit | Line | Data |
---|---|---|
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, | |
77968b78 | 293 | struct flowi4 *fl4, |
2e77d89b | 294 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 295 | { |
1e3cf683 | 296 | struct sock *sk; |
1da177e4 LT |
297 | struct sk_buff *skb; |
298 | ||
d8d1f30b | 299 | sk = icmp_sk(dev_net((*rt)->dst.dev)); |
1e3cf683 | 300 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
301 | icmp_param->data_len+icmp_param->head_len, |
302 | icmp_param->head_len, | |
1f8438a8 ED |
303 | ipc, rt, MSG_DONTWAIT) < 0) { |
304 | ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS); | |
1e3cf683 | 305 | ip_flush_pending_frames(sk); |
1f8438a8 | 306 | } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
88c7664f | 307 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 308 | __wsum csum = 0; |
1da177e4 LT |
309 | struct sk_buff *skb1; |
310 | ||
1e3cf683 | 311 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
312 | csum = csum_add(csum, skb1->csum); |
313 | } | |
314 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
315 | (char *)icmph, | |
316 | icmp_param->head_len, csum); | |
317 | icmph->checksum = csum_fold(csum); | |
318 | skb->ip_summed = CHECKSUM_NONE; | |
77968b78 | 319 | ip_push_pending_frames(sk, fl4); |
1da177e4 LT |
320 | } |
321 | } | |
322 | ||
323 | /* | |
324 | * Driving logic for building and sending ICMP messages. | |
325 | */ | |
326 | ||
327 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
328 | { | |
1da177e4 | 329 | struct ipcm_cookie ipc; |
511c3f92 | 330 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 331 | struct net *net = dev_net(rt->dst.dev); |
77968b78 | 332 | struct flowi4 fl4; |
fdc0bde9 DL |
333 | struct sock *sk; |
334 | struct inet_sock *inet; | |
3ca3c68e | 335 | __be32 daddr; |
1da177e4 | 336 | |
f6d8bd05 | 337 | if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb)) |
f00c401b | 338 | return; |
1da177e4 | 339 | |
fdc0bde9 DL |
340 | sk = icmp_xmit_lock(net); |
341 | if (sk == NULL) | |
1da177e4 | 342 | return; |
fdc0bde9 | 343 | inet = inet_sk(sk); |
1da177e4 LT |
344 | |
345 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 346 | |
eddc9ec5 | 347 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
348 | daddr = ipc.addr = rt->rt_src; |
349 | ipc.opt = NULL; | |
2244d07b | 350 | ipc.tx_flags = 0; |
f6d8bd05 ED |
351 | if (icmp_param->replyopts.opt.opt.optlen) { |
352 | ipc.opt = &icmp_param->replyopts.opt; | |
353 | if (ipc.opt->opt.srr) | |
354 | daddr = icmp_param->replyopts.opt.opt.faddr; | |
1da177e4 | 355 | } |
77968b78 DM |
356 | memset(&fl4, 0, sizeof(fl4)); |
357 | fl4.daddr = daddr; | |
358 | fl4.saddr = rt->rt_spec_dst; | |
359 | fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos); | |
360 | fl4.flowi4_proto = IPPROTO_ICMP; | |
361 | security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); | |
362 | rt = ip_route_output_key(net, &fl4); | |
363 | if (IS_ERR(rt)) | |
364 | goto out_unlock; | |
b34a95ee | 365 | if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, |
1da177e4 | 366 | icmp_param->data.icmph.code)) |
77968b78 | 367 | icmp_push_reply(icmp_param, &fl4, &ipc, &rt); |
1da177e4 LT |
368 | ip_rt_put(rt); |
369 | out_unlock: | |
405666db | 370 | icmp_xmit_unlock(sk); |
1da177e4 LT |
371 | } |
372 | ||
77968b78 DM |
373 | static struct rtable *icmp_route_lookup(struct net *net, |
374 | struct flowi4 *fl4, | |
375 | struct sk_buff *skb_in, | |
b71d1d42 | 376 | const struct iphdr *iph, |
f6d460cf DM |
377 | __be32 saddr, u8 tos, |
378 | int type, int code, | |
379 | struct icmp_bxm *param) | |
380 | { | |
f6d460cf DM |
381 | struct rtable *rt, *rt2; |
382 | int err; | |
383 | ||
77968b78 DM |
384 | memset(fl4, 0, sizeof(*fl4)); |
385 | fl4->daddr = (param->replyopts.opt.opt.srr ? | |
386 | param->replyopts.opt.opt.faddr : iph->saddr); | |
387 | fl4->saddr = saddr; | |
388 | fl4->flowi4_tos = RT_TOS(tos); | |
389 | fl4->flowi4_proto = IPPROTO_ICMP; | |
390 | fl4->fl4_icmp_type = type; | |
391 | fl4->fl4_icmp_code = code; | |
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 | 400 | rt = (struct rtable *) xfrm_lookup(net, &rt->dst, |
77968b78 | 401 | flowi4_to_flowi(fl4), NULL, 0); |
452edd59 | 402 | if (!IS_ERR(rt)) { |
f6d460cf DM |
403 | if (rt != rt2) |
404 | return rt; | |
452edd59 | 405 | } else if (PTR_ERR(rt) == -EPERM) { |
f6d460cf | 406 | rt = NULL; |
452edd59 DM |
407 | } else |
408 | return rt; | |
f6d460cf | 409 | |
77968b78 | 410 | err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(fl4), AF_INET); |
f6d460cf DM |
411 | if (err) |
412 | goto relookup_failed; | |
413 | ||
77968b78 DM |
414 | if (inet_addr_type(net, fl4->saddr) == RTN_LOCAL) { |
415 | rt2 = __ip_route_output_key(net, fl4); | |
b23dd4fe DM |
416 | if (IS_ERR(rt2)) |
417 | err = PTR_ERR(rt2); | |
f6d460cf | 418 | } else { |
9d6ec938 | 419 | struct flowi4 fl4_2 = {}; |
f6d460cf DM |
420 | unsigned long orefdst; |
421 | ||
77968b78 | 422 | fl4_2.daddr = fl4->saddr; |
9d6ec938 | 423 | rt2 = ip_route_output_key(net, &fl4_2); |
b23dd4fe DM |
424 | if (IS_ERR(rt2)) { |
425 | err = PTR_ERR(rt2); | |
f6d460cf | 426 | goto relookup_failed; |
b23dd4fe | 427 | } |
f6d460cf DM |
428 | /* Ugh! */ |
429 | orefdst = skb_in->_skb_refdst; /* save old refdst */ | |
77968b78 | 430 | err = ip_route_input(skb_in, fl4->daddr, fl4->saddr, |
f6d460cf DM |
431 | RT_TOS(tos), rt2->dst.dev); |
432 | ||
433 | dst_release(&rt2->dst); | |
434 | rt2 = skb_rtable(skb_in); | |
435 | skb_in->_skb_refdst = orefdst; /* restore old refdst */ | |
436 | } | |
437 | ||
438 | if (err) | |
439 | goto relookup_failed; | |
440 | ||
9d6ec938 | 441 | rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst, |
77968b78 | 442 | flowi4_to_flowi(fl4), NULL, |
9d6ec938 | 443 | XFRM_LOOKUP_ICMP); |
452edd59 | 444 | if (!IS_ERR(rt2)) { |
f6d460cf DM |
445 | dst_release(&rt->dst); |
446 | rt = rt2; | |
452edd59 DM |
447 | } else if (PTR_ERR(rt2) == -EPERM) { |
448 | if (rt) | |
449 | dst_release(&rt->dst); | |
450 | return rt2; | |
451 | } else { | |
452 | err = PTR_ERR(rt2); | |
453 | goto relookup_failed; | |
f6d460cf | 454 | } |
f6d460cf DM |
455 | return rt; |
456 | ||
457 | relookup_failed: | |
458 | if (rt) | |
459 | return rt; | |
460 | return ERR_PTR(err); | |
461 | } | |
1da177e4 LT |
462 | |
463 | /* | |
464 | * Send an ICMP message in response to a situation | |
465 | * | |
466 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
467 | * MAY send more (we do). | |
468 | * MUST NOT change this header information. | |
469 | * MUST NOT reply to a multicast/broadcast IP address. | |
470 | * MUST NOT reply to a multicast/broadcast MAC address. | |
471 | * MUST reply to only the first fragment. | |
472 | */ | |
473 | ||
e4883014 | 474 | void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
1da177e4 LT |
475 | { |
476 | struct iphdr *iph; | |
477 | int room; | |
478 | struct icmp_bxm icmp_param; | |
511c3f92 | 479 | struct rtable *rt = skb_rtable(skb_in); |
1da177e4 | 480 | struct ipcm_cookie ipc; |
77968b78 | 481 | struct flowi4 fl4; |
a61ced5d | 482 | __be32 saddr; |
1da177e4 | 483 | u8 tos; |
dde1bc0e | 484 | struct net *net; |
4a6ad7a1 | 485 | struct sock *sk; |
1da177e4 LT |
486 | |
487 | if (!rt) | |
488 | goto out; | |
d8d1f30b | 489 | net = dev_net(rt->dst.dev); |
1da177e4 LT |
490 | |
491 | /* | |
492 | * Find the original header. It is expected to be valid, of course. | |
493 | * Check this, icmp_send is called from the most obscure devices | |
494 | * sometimes. | |
495 | */ | |
eddc9ec5 | 496 | iph = ip_hdr(skb_in); |
1da177e4 | 497 | |
27a884dc ACM |
498 | if ((u8 *)iph < skb_in->head || |
499 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
500 | goto out; |
501 | ||
502 | /* | |
503 | * No replies to physical multicast/broadcast | |
504 | */ | |
505 | if (skb_in->pkt_type != PACKET_HOST) | |
506 | goto out; | |
507 | ||
508 | /* | |
509 | * Now check at the protocol level | |
510 | */ | |
511 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
512 | goto out; | |
513 | ||
514 | /* | |
515 | * Only reply to fragment 0. We byte re-order the constant | |
516 | * mask for efficiency. | |
517 | */ | |
518 | if (iph->frag_off & htons(IP_OFFSET)) | |
519 | goto out; | |
520 | ||
521 | /* | |
522 | * If we send an ICMP error to an ICMP error a mess would result.. | |
523 | */ | |
524 | if (icmp_pointers[type].error) { | |
525 | /* | |
526 | * We are an error, check if we are replying to an | |
527 | * ICMP error | |
528 | */ | |
529 | if (iph->protocol == IPPROTO_ICMP) { | |
530 | u8 _inner_type, *itp; | |
531 | ||
532 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 533 | skb_network_header(skb_in) + |
1da177e4 LT |
534 | (iph->ihl << 2) + |
535 | offsetof(struct icmphdr, | |
536 | type) - | |
537 | skb_in->data, | |
538 | sizeof(_inner_type), | |
539 | &_inner_type); | |
540 | if (itp == NULL) | |
541 | goto out; | |
542 | ||
543 | /* | |
544 | * Assume any unknown ICMP type is an error. This | |
545 | * isn't specified by the RFC, but think about it.. | |
546 | */ | |
547 | if (*itp > NR_ICMP_TYPES || | |
548 | icmp_pointers[*itp].error) | |
549 | goto out; | |
550 | } | |
551 | } | |
552 | ||
fdc0bde9 DL |
553 | sk = icmp_xmit_lock(net); |
554 | if (sk == NULL) | |
1da177e4 LT |
555 | return; |
556 | ||
557 | /* | |
558 | * Construct source address and options. | |
559 | */ | |
560 | ||
561 | saddr = iph->daddr; | |
1c2fb7f9 | 562 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
563 | struct net_device *dev = NULL; |
564 | ||
685c7944 | 565 | rcu_read_lock(); |
c7537967 DM |
566 | if (rt_is_input_route(rt) && |
567 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) | |
5e2b61f7 | 568 | dev = dev_get_by_index_rcu(net, rt->rt_iif); |
6e1d9103 | 569 | |
685c7944 | 570 | if (dev) |
6e1d9103 | 571 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
685c7944 | 572 | else |
1c2fb7f9 | 573 | saddr = 0; |
685c7944 | 574 | rcu_read_unlock(); |
1c2fb7f9 | 575 | } |
1da177e4 LT |
576 | |
577 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
578 | IPTOS_PREC_INTERNETCONTROL) : | |
579 | iph->tos; | |
580 | ||
f6d8bd05 | 581 | if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in)) |
fa60cf7f | 582 | goto out_unlock; |
1da177e4 LT |
583 | |
584 | ||
585 | /* | |
586 | * Prepare data for ICMP header. | |
587 | */ | |
588 | ||
589 | icmp_param.data.icmph.type = type; | |
590 | icmp_param.data.icmph.code = code; | |
591 | icmp_param.data.icmph.un.gateway = info; | |
592 | icmp_param.data.icmph.checksum = 0; | |
593 | icmp_param.skb = skb_in; | |
d56f90a7 | 594 | icmp_param.offset = skb_network_offset(skb_in); |
405666db | 595 | inet_sk(sk)->tos = tos; |
1da177e4 | 596 | ipc.addr = iph->saddr; |
f6d8bd05 | 597 | ipc.opt = &icmp_param.replyopts.opt; |
2244d07b | 598 | ipc.tx_flags = 0; |
1da177e4 | 599 | |
77968b78 | 600 | rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, |
f6d460cf DM |
601 | type, code, &icmp_param); |
602 | if (IS_ERR(rt)) | |
603 | goto out_unlock; | |
1da177e4 | 604 | |
b34a95ee | 605 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
606 | goto ende; |
607 | ||
608 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
609 | ||
d8d1f30b | 610 | room = dst_mtu(&rt->dst); |
1da177e4 LT |
611 | if (room > 576) |
612 | room = 576; | |
f6d8bd05 | 613 | room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; |
1da177e4 LT |
614 | room -= sizeof(struct icmphdr); |
615 | ||
616 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
617 | if (icmp_param.data_len > room) | |
618 | icmp_param.data_len = room; | |
619 | icmp_param.head_len = sizeof(struct icmphdr); | |
620 | ||
77968b78 | 621 | icmp_push_reply(&icmp_param, &fl4, &ipc, &rt); |
1da177e4 LT |
622 | ende: |
623 | ip_rt_put(rt); | |
624 | out_unlock: | |
405666db | 625 | icmp_xmit_unlock(sk); |
1da177e4 LT |
626 | out:; |
627 | } | |
4bc2f18b | 628 | EXPORT_SYMBOL(icmp_send); |
1da177e4 LT |
629 | |
630 | ||
631 | /* | |
632 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
633 | */ | |
634 | ||
635 | static void icmp_unreach(struct sk_buff *skb) | |
636 | { | |
b71d1d42 | 637 | const struct iphdr *iph; |
1da177e4 LT |
638 | struct icmphdr *icmph; |
639 | int hash, protocol; | |
32613090 | 640 | const struct net_protocol *ipprot; |
1da177e4 | 641 | u32 info = 0; |
dde1bc0e DL |
642 | struct net *net; |
643 | ||
adf30907 | 644 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
645 | |
646 | /* | |
647 | * Incomplete header ? | |
648 | * Only checks for the IP header, there should be an | |
649 | * additional check for longer headers in upper levels. | |
650 | */ | |
651 | ||
652 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
653 | goto out_err; | |
654 | ||
88c7664f | 655 | icmph = icmp_hdr(skb); |
b71d1d42 | 656 | iph = (const struct iphdr *)skb->data; |
1da177e4 LT |
657 | |
658 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
659 | goto out_err; | |
660 | ||
661 | if (icmph->type == ICMP_DEST_UNREACH) { | |
662 | switch (icmph->code & 15) { | |
663 | case ICMP_NET_UNREACH: | |
664 | case ICMP_HOST_UNREACH: | |
665 | case ICMP_PROT_UNREACH: | |
666 | case ICMP_PORT_UNREACH: | |
667 | break; | |
668 | case ICMP_FRAG_NEEDED: | |
669 | if (ipv4_config.no_pmtu_disc) { | |
673d57e7 HH |
670 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: fragmentation needed and DF set.\n", |
671 | &iph->daddr); | |
1da177e4 | 672 | } else { |
dde1bc0e | 673 | info = ip_rt_frag_needed(net, iph, |
0010e465 TT |
674 | ntohs(icmph->un.frag.mtu), |
675 | skb->dev); | |
1da177e4 LT |
676 | if (!info) |
677 | goto out; | |
678 | } | |
679 | break; | |
680 | case ICMP_SR_FAILED: | |
673d57e7 HH |
681 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: Source Route Failed.\n", |
682 | &iph->daddr); | |
1da177e4 LT |
683 | break; |
684 | default: | |
685 | break; | |
686 | } | |
687 | if (icmph->code > NR_ICMP_UNREACH) | |
688 | goto out; | |
689 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
690 | info = ntohl(icmph->un.gateway) >> 24; | |
691 | ||
692 | /* | |
693 | * Throw it at our lower layers | |
694 | * | |
695 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
696 | * header. | |
697 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
698 | * transport layer. | |
699 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
700 | * transport layer. | |
701 | */ | |
702 | ||
703 | /* | |
25985edc | 704 | * Check the other end isn't violating RFC 1122. Some routers send |
1da177e4 LT |
705 | * bogus responses to broadcast frames. If you see this message |
706 | * first check your netmask matches at both ends, if it does then | |
707 | * get the other vendor to fix their kit. | |
708 | */ | |
709 | ||
b34a95ee | 710 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 711 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 | 712 | if (net_ratelimit()) |
673d57e7 | 713 | printk(KERN_WARNING "%pI4 sent an invalid ICMP " |
1da177e4 | 714 | "type %u, code %u " |
673d57e7 HH |
715 | "error to a broadcast: %pI4 on %s\n", |
716 | &ip_hdr(skb)->saddr, | |
1da177e4 | 717 | icmph->type, icmph->code, |
673d57e7 | 718 | &iph->daddr, |
1da177e4 LT |
719 | skb->dev->name); |
720 | goto out; | |
721 | } | |
722 | ||
723 | /* Checkin full IP header plus 8 bytes of protocol to | |
724 | * avoid additional coding at protocol handlers. | |
725 | */ | |
726 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
727 | goto out; | |
728 | ||
b71d1d42 | 729 | iph = (const struct iphdr *)skb->data; |
1da177e4 LT |
730 | protocol = iph->protocol; |
731 | ||
732 | /* | |
733 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
734 | */ | |
7bc54c90 | 735 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 736 | |
1da177e4 | 737 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
738 | rcu_read_lock(); |
739 | ipprot = rcu_dereference(inet_protos[hash]); | |
740 | if (ipprot && ipprot->err_handler) | |
741 | ipprot->err_handler(skb, info); | |
742 | rcu_read_unlock(); | |
743 | ||
744 | out: | |
745 | return; | |
746 | out_err: | |
dcfc23ca | 747 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
748 | goto out; |
749 | } | |
750 | ||
751 | ||
752 | /* | |
753 | * Handle ICMP_REDIRECT. | |
754 | */ | |
755 | ||
756 | static void icmp_redirect(struct sk_buff *skb) | |
757 | { | |
b71d1d42 | 758 | const struct iphdr *iph; |
1da177e4 LT |
759 | |
760 | if (skb->len < sizeof(struct iphdr)) | |
761 | goto out_err; | |
762 | ||
763 | /* | |
764 | * Get the copied header of the packet that caused the redirect | |
765 | */ | |
766 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
767 | goto out; | |
768 | ||
b71d1d42 | 769 | iph = (const struct iphdr *)skb->data; |
1da177e4 | 770 | |
88c7664f | 771 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
772 | case ICMP_REDIR_NET: |
773 | case ICMP_REDIR_NETTOS: | |
774 | /* | |
775 | * As per RFC recommendations now handle it as a host redirect. | |
776 | */ | |
777 | case ICMP_REDIR_HOST: | |
778 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 779 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 780 | icmp_hdr(skb)->un.gateway, |
cef2685e | 781 | iph->saddr, skb->dev); |
1da177e4 | 782 | break; |
e905a9ed | 783 | } |
1da177e4 LT |
784 | out: |
785 | return; | |
786 | out_err: | |
dcfc23ca | 787 | ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
788 | goto out; |
789 | } | |
790 | ||
791 | /* | |
792 | * Handle ICMP_ECHO ("ping") requests. | |
793 | * | |
794 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
795 | * requests. | |
796 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
797 | * included in the reply. | |
798 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
799 | * echo requests, MUST have default=NOT. | |
800 | * See also WRT handling of options once they are done and working. | |
801 | */ | |
802 | ||
803 | static void icmp_echo(struct sk_buff *skb) | |
804 | { | |
b34a95ee PE |
805 | struct net *net; |
806 | ||
adf30907 | 807 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 808 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
809 | struct icmp_bxm icmp_param; |
810 | ||
88c7664f | 811 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
812 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
813 | icmp_param.skb = skb; | |
814 | icmp_param.offset = 0; | |
815 | icmp_param.data_len = skb->len; | |
816 | icmp_param.head_len = sizeof(struct icmphdr); | |
817 | icmp_reply(&icmp_param, skb); | |
818 | } | |
819 | } | |
820 | ||
821 | /* | |
822 | * Handle ICMP Timestamp requests. | |
823 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
824 | * SHOULD be in the kernel for minimum random latency. | |
825 | * MUST be accurate to a few minutes. | |
826 | * MUST be updated at least at 15Hz. | |
827 | */ | |
828 | static void icmp_timestamp(struct sk_buff *skb) | |
829 | { | |
f25c3d61 | 830 | struct timespec tv; |
1da177e4 LT |
831 | struct icmp_bxm icmp_param; |
832 | /* | |
833 | * Too short. | |
834 | */ | |
835 | if (skb->len < 4) | |
836 | goto out_err; | |
837 | ||
838 | /* | |
839 | * Fill in the current time as ms since midnight UT: | |
840 | */ | |
f25c3d61 YH |
841 | getnstimeofday(&tv); |
842 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + | |
843 | tv.tv_nsec / NSEC_PER_MSEC); | |
1da177e4 LT |
844 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
845 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
846 | BUG(); | |
88c7664f | 847 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
848 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
849 | icmp_param.data.icmph.code = 0; | |
850 | icmp_param.skb = skb; | |
851 | icmp_param.offset = 0; | |
852 | icmp_param.data_len = 0; | |
853 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
854 | icmp_reply(&icmp_param, skb); | |
855 | out: | |
856 | return; | |
857 | out_err: | |
adf30907 | 858 | ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
859 | goto out; |
860 | } | |
861 | ||
862 | ||
863 | /* | |
864 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
865 | * | |
866 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
867 | * ADDRESS_MASK requests if it's been configured as an address mask | |
868 | * agent. Receiving a request doesn't constitute implicit permission to | |
869 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
870 | * a way to turn the functionality on and off. Another one for sysctl(), | |
871 | * I guess. -- MS | |
872 | * | |
873 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
874 | * A router SHOULD have switch turning it on/off. | |
875 | * This switch MUST be ON by default. | |
876 | * | |
877 | * Gratuitous replies, zero-source replies are not implemented, | |
878 | * that complies with RFC. DO NOT implement them!!! All the idea | |
879 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
880 | * The problem is that it is not uncommon to have several prefixes | |
881 | * on one physical interface. Moreover, addrmask agent can even be | |
882 | * not aware of existing another prefixes. | |
883 | * If source is zero, addrmask agent cannot choose correct prefix. | |
884 | * Gratuitous mask announcements suffer from the same problem. | |
885 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
886 | * that is pretty silly. --ANK | |
887 | * | |
888 | * All these rules are so bizarre, that I removed kernel addrmask | |
889 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
890 | * any case. --ANK | |
891 | * | |
892 | * Furthermore you can do it with a usermode address agent program | |
893 | * anyway... | |
894 | */ | |
895 | ||
896 | static void icmp_address(struct sk_buff *skb) | |
897 | { | |
898 | #if 0 | |
899 | if (net_ratelimit()) | |
900 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
901 | #endif | |
902 | } | |
903 | ||
904 | /* | |
905 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
906 | * loudly if an inconsistency is found. | |
cfa087f6 | 907 | * called with rcu_read_lock() |
1da177e4 LT |
908 | */ |
909 | ||
910 | static void icmp_address_reply(struct sk_buff *skb) | |
911 | { | |
511c3f92 | 912 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
913 | struct net_device *dev = skb->dev; |
914 | struct in_device *in_dev; | |
915 | struct in_ifaddr *ifa; | |
916 | ||
917 | if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC)) | |
cfa087f6 | 918 | return; |
1da177e4 | 919 | |
cfa087f6 | 920 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 | 921 | if (!in_dev) |
cfa087f6 ED |
922 | return; |
923 | ||
1da177e4 LT |
924 | if (in_dev->ifa_list && |
925 | IN_DEV_LOG_MARTIANS(in_dev) && | |
926 | IN_DEV_FORWARD(in_dev)) { | |
a144ea4b | 927 | __be32 _mask, *mp; |
1da177e4 LT |
928 | |
929 | mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask); | |
09a62660 | 930 | BUG_ON(mp == NULL); |
1da177e4 LT |
931 | for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { |
932 | if (*mp == ifa->ifa_mask && | |
933 | inet_ifa_match(rt->rt_src, ifa)) | |
934 | break; | |
935 | } | |
936 | if (!ifa && net_ratelimit()) { | |
673d57e7 HH |
937 | printk(KERN_INFO "Wrong address mask %pI4 from %s/%pI4\n", |
938 | mp, dev->name, &rt->rt_src); | |
1da177e4 LT |
939 | } |
940 | } | |
1da177e4 LT |
941 | } |
942 | ||
943 | static void icmp_discard(struct sk_buff *skb) | |
944 | { | |
945 | } | |
946 | ||
947 | /* | |
948 | * Deal with incoming ICMP packets. | |
949 | */ | |
950 | int icmp_rcv(struct sk_buff *skb) | |
951 | { | |
952 | struct icmphdr *icmph; | |
511c3f92 | 953 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 954 | struct net *net = dev_net(rt->dst.dev); |
1da177e4 | 955 | |
aebcf82c | 956 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 957 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
958 | int nh; |
959 | ||
def8b4fa | 960 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
961 | XFRM_STATE_ICMP)) |
962 | goto drop; | |
963 | ||
8b7817f3 HX |
964 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
965 | goto drop; | |
966 | ||
967 | nh = skb_network_offset(skb); | |
968 | skb_set_network_header(skb, sizeof(*icmph)); | |
969 | ||
970 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
971 | goto drop; | |
972 | ||
973 | skb_set_network_header(skb, nh); | |
974 | } | |
975 | ||
dcfc23ca | 976 | ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS); |
1da177e4 LT |
977 | |
978 | switch (skb->ip_summed) { | |
84fa7933 | 979 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 980 | if (!csum_fold(skb->csum)) |
1da177e4 | 981 | break; |
fb286bb2 | 982 | /* fall through */ |
1da177e4 | 983 | case CHECKSUM_NONE: |
fb286bb2 HX |
984 | skb->csum = 0; |
985 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 986 | goto error; |
1da177e4 LT |
987 | } |
988 | ||
8cf22943 HX |
989 | if (!pskb_pull(skb, sizeof(*icmph))) |
990 | goto error; | |
1da177e4 | 991 | |
88c7664f | 992 | icmph = icmp_hdr(skb); |
1da177e4 | 993 | |
f66ac03d | 994 | ICMPMSGIN_INC_STATS_BH(net, icmph->type); |
1da177e4 LT |
995 | /* |
996 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
997 | * | |
998 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
999 | * discarded. | |
1000 | */ | |
1001 | if (icmph->type > NR_ICMP_TYPES) | |
1002 | goto error; | |
1003 | ||
1004 | ||
1005 | /* | |
1006 | * Parse the ICMP message | |
1007 | */ | |
1008 | ||
e905a9ed | 1009 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1010 | /* |
1011 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1012 | * silently ignored (we let user decide with a sysctl). | |
1013 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1014 | * discarded if to broadcast/multicast. | |
1015 | */ | |
4c866aa7 AK |
1016 | if ((icmph->type == ICMP_ECHO || |
1017 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1018 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1019 | goto error; |
1020 | } | |
1021 | if (icmph->type != ICMP_ECHO && | |
1022 | icmph->type != ICMP_TIMESTAMP && | |
1023 | icmph->type != ICMP_ADDRESS && | |
1024 | icmph->type != ICMP_ADDRESSREPLY) { | |
1025 | goto error; | |
e905a9ed | 1026 | } |
1da177e4 LT |
1027 | } |
1028 | ||
1da177e4 LT |
1029 | icmp_pointers[icmph->type].handler(skb); |
1030 | ||
1031 | drop: | |
1032 | kfree_skb(skb); | |
1033 | return 0; | |
1034 | error: | |
dcfc23ca | 1035 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1036 | goto drop; |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * This table is the definition of how we handle ICMP. | |
1041 | */ | |
9b5b5cff | 1042 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1043 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1044 | .handler = icmp_discard, |
1045 | }, | |
1046 | [1] = { | |
1da177e4 LT |
1047 | .handler = icmp_discard, |
1048 | .error = 1, | |
1049 | }, | |
1050 | [2] = { | |
1da177e4 LT |
1051 | .handler = icmp_discard, |
1052 | .error = 1, | |
1053 | }, | |
1054 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1055 | .handler = icmp_unreach, |
1056 | .error = 1, | |
1057 | }, | |
1058 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1059 | .handler = icmp_unreach, |
1060 | .error = 1, | |
1061 | }, | |
1062 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1063 | .handler = icmp_redirect, |
1064 | .error = 1, | |
1065 | }, | |
1066 | [6] = { | |
1da177e4 LT |
1067 | .handler = icmp_discard, |
1068 | .error = 1, | |
1069 | }, | |
1070 | [7] = { | |
1da177e4 LT |
1071 | .handler = icmp_discard, |
1072 | .error = 1, | |
1073 | }, | |
1074 | [ICMP_ECHO] = { | |
1da177e4 LT |
1075 | .handler = icmp_echo, |
1076 | }, | |
1077 | [9] = { | |
1da177e4 LT |
1078 | .handler = icmp_discard, |
1079 | .error = 1, | |
1080 | }, | |
1081 | [10] = { | |
1da177e4 LT |
1082 | .handler = icmp_discard, |
1083 | .error = 1, | |
1084 | }, | |
1085 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1086 | .handler = icmp_unreach, |
1087 | .error = 1, | |
1088 | }, | |
1089 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1090 | .handler = icmp_unreach, |
1091 | .error = 1, | |
1092 | }, | |
1093 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1094 | .handler = icmp_timestamp, |
1095 | }, | |
1096 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1097 | .handler = icmp_discard, |
1098 | }, | |
1099 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1100 | .handler = icmp_discard, |
1101 | }, | |
e905a9ed | 1102 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1103 | .handler = icmp_discard, |
1104 | }, | |
1105 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1106 | .handler = icmp_address, |
1107 | }, | |
1108 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1109 | .handler = icmp_address_reply, |
1110 | }, | |
1111 | }; | |
1112 | ||
4a6ad7a1 | 1113 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1114 | { |
1da177e4 LT |
1115 | int i; |
1116 | ||
5c8cafd6 | 1117 | for_each_possible_cpu(i) |
c1e9894d | 1118 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
4a6ad7a1 DL |
1119 | kfree(net->ipv4.icmp_sk); |
1120 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1121 | } |
1da177e4 | 1122 | |
263173af | 1123 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1124 | { |
a5710d65 DL |
1125 | int i, err; |
1126 | ||
4a6ad7a1 DL |
1127 | net->ipv4.icmp_sk = |
1128 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1129 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1130 | return -ENOMEM; |
1131 | ||
a5710d65 | 1132 | for_each_possible_cpu(i) { |
1e3cf683 | 1133 | struct sock *sk; |
1da177e4 | 1134 | |
c1e9894d DL |
1135 | err = inet_ctl_sock_create(&sk, PF_INET, |
1136 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1137 | if (err < 0) |
a5710d65 | 1138 | goto fail; |
1da177e4 | 1139 | |
c1e9894d | 1140 | net->ipv4.icmp_sk[i] = sk; |
1da177e4 LT |
1141 | |
1142 | /* Enough space for 2 64K ICMP packets, including | |
1143 | * sk_buff struct overhead. | |
1144 | */ | |
1e3cf683 | 1145 | sk->sk_sndbuf = |
1da177e4 LT |
1146 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1147 | ||
b3a5b6cc ED |
1148 | /* |
1149 | * Speedup sock_wfree() | |
1150 | */ | |
1151 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
c1e9894d | 1152 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1153 | } |
a24022e1 PE |
1154 | |
1155 | /* Control parameters for ECHO replies. */ | |
1156 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1157 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1158 | ||
1159 | /* Control parameter - ignore bogus broadcast responses? */ | |
1160 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1161 | ||
1162 | /* | |
1163 | * Configurable global rate limit. | |
1164 | * | |
1165 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1166 | * bucket ratemask defines which icmp types are ratelimited by | |
1167 | * setting it's bit position. | |
1168 | * | |
1169 | * default: | |
1170 | * dest unreachable (3), source quench (4), | |
1171 | * time exceeded (11), parameter problem (12) | |
1172 | */ | |
1173 | ||
1174 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1175 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1176 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1177 | ||
a5710d65 DL |
1178 | return 0; |
1179 | ||
1180 | fail: | |
1d1c8d13 | 1181 | for_each_possible_cpu(i) |
c1e9894d | 1182 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
1d1c8d13 | 1183 | kfree(net->ipv4.icmp_sk); |
a5710d65 | 1184 | return err; |
1da177e4 LT |
1185 | } |
1186 | ||
4a6ad7a1 DL |
1187 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1188 | .init = icmp_sk_init, | |
1189 | .exit = icmp_sk_exit, | |
1190 | }; | |
1191 | ||
1192 | int __init icmp_init(void) | |
1193 | { | |
959d2726 | 1194 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 | 1195 | } |