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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; | |
111 | struct ip_options replyopts; | |
112 | unsigned char optbuf[40]; | |
113 | }; | |
114 | ||
1da177e4 LT |
115 | /* An array of errno for error messages from dest unreach. */ |
116 | /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */ | |
117 | ||
e754834e | 118 | const struct icmp_err icmp_err_convert[] = { |
1da177e4 LT |
119 | { |
120 | .errno = ENETUNREACH, /* ICMP_NET_UNREACH */ | |
121 | .fatal = 0, | |
122 | }, | |
123 | { | |
124 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */ | |
125 | .fatal = 0, | |
126 | }, | |
127 | { | |
128 | .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */, | |
129 | .fatal = 1, | |
130 | }, | |
131 | { | |
132 | .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */ | |
133 | .fatal = 1, | |
134 | }, | |
135 | { | |
136 | .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */ | |
137 | .fatal = 0, | |
138 | }, | |
139 | { | |
140 | .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */ | |
141 | .fatal = 0, | |
142 | }, | |
143 | { | |
144 | .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */ | |
145 | .fatal = 1, | |
146 | }, | |
147 | { | |
148 | .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */ | |
149 | .fatal = 1, | |
150 | }, | |
151 | { | |
152 | .errno = ENONET, /* ICMP_HOST_ISOLATED */ | |
153 | .fatal = 1, | |
154 | }, | |
155 | { | |
156 | .errno = ENETUNREACH, /* ICMP_NET_ANO */ | |
157 | .fatal = 1, | |
158 | }, | |
159 | { | |
160 | .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */ | |
161 | .fatal = 1, | |
162 | }, | |
163 | { | |
164 | .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */ | |
165 | .fatal = 0, | |
166 | }, | |
167 | { | |
168 | .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */ | |
169 | .fatal = 0, | |
170 | }, | |
171 | { | |
172 | .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */ | |
173 | .fatal = 1, | |
174 | }, | |
175 | { | |
176 | .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */ | |
177 | .fatal = 1, | |
178 | }, | |
179 | { | |
180 | .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */ | |
181 | .fatal = 1, | |
182 | }, | |
183 | }; | |
4bc2f18b | 184 | EXPORT_SYMBOL(icmp_err_convert); |
1da177e4 | 185 | |
1da177e4 LT |
186 | /* |
187 | * ICMP control array. This specifies what to do with each ICMP. | |
188 | */ | |
189 | ||
190 | struct icmp_control { | |
1da177e4 LT |
191 | void (*handler)(struct sk_buff *skb); |
192 | short error; /* This ICMP is classed as an error message */ | |
193 | }; | |
194 | ||
9b5b5cff | 195 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1]; |
1da177e4 LT |
196 | |
197 | /* | |
198 | * The ICMP socket(s). This is the most convenient way to flow control | |
199 | * our ICMP output as well as maintain a clean interface throughout | |
200 | * all layers. All Socketless IP sends will soon be gone. | |
201 | * | |
202 | * On SMP we have one ICMP socket per-cpu. | |
203 | */ | |
4a6ad7a1 DL |
204 | static struct sock *icmp_sk(struct net *net) |
205 | { | |
206 | return net->ipv4.icmp_sk[smp_processor_id()]; | |
207 | } | |
1da177e4 | 208 | |
fdc0bde9 | 209 | static inline struct sock *icmp_xmit_lock(struct net *net) |
1da177e4 | 210 | { |
fdc0bde9 DL |
211 | struct sock *sk; |
212 | ||
1da177e4 LT |
213 | local_bh_disable(); |
214 | ||
fdc0bde9 DL |
215 | sk = icmp_sk(net); |
216 | ||
405666db | 217 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
218 | /* This can happen if the output path signals a |
219 | * dst_link_failure() for an outgoing ICMP packet. | |
220 | */ | |
221 | local_bh_enable(); | |
fdc0bde9 | 222 | return NULL; |
1da177e4 | 223 | } |
fdc0bde9 | 224 | return sk; |
1da177e4 LT |
225 | } |
226 | ||
405666db | 227 | static inline void icmp_xmit_unlock(struct sock *sk) |
1da177e4 | 228 | { |
405666db | 229 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
230 | } |
231 | ||
232 | /* | |
233 | * Send an ICMP frame. | |
234 | */ | |
235 | ||
236 | /* | |
237 | * Check transmit rate limitation for given message. | |
238 | * The rate information is held in the destination cache now. | |
239 | * This function is generic and could be used for other purposes | |
240 | * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov. | |
241 | * | |
242 | * Note that the same dst_entry fields are modified by functions in | |
243 | * route.c too, but these work for packet destinations while xrlim_allow | |
244 | * works for icmp destinations. This means the rate limiting information | |
245 | * for one "ip object" is shared - and these ICMPs are twice limited: | |
246 | * by source and by destination. | |
247 | * | |
248 | * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate | |
249 | * SHOULD allow setting of rate limits | |
250 | * | |
251 | * Shared between ICMPv4 and ICMPv6. | |
252 | */ | |
253 | #define XRLIM_BURST_FACTOR 6 | |
254 | int xrlim_allow(struct dst_entry *dst, int timeout) | |
255 | { | |
69a73829 | 256 | unsigned long now, token = dst->rate_tokens; |
1da177e4 LT |
257 | int rc = 0; |
258 | ||
259 | now = jiffies; | |
69a73829 | 260 | token += now - dst->rate_last; |
1da177e4 | 261 | dst->rate_last = now; |
69a73829 ED |
262 | if (token > XRLIM_BURST_FACTOR * timeout) |
263 | token = XRLIM_BURST_FACTOR * timeout; | |
264 | if (token >= timeout) { | |
265 | token -= timeout; | |
1da177e4 LT |
266 | rc = 1; |
267 | } | |
69a73829 | 268 | dst->rate_tokens = token; |
1da177e4 LT |
269 | return rc; |
270 | } | |
4bc2f18b | 271 | EXPORT_SYMBOL(xrlim_allow); |
1da177e4 | 272 | |
b34a95ee PE |
273 | static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
274 | int type, int code) | |
1da177e4 | 275 | { |
d8d1f30b | 276 | struct dst_entry *dst = &rt->dst; |
1da177e4 LT |
277 | int rc = 1; |
278 | ||
279 | if (type > NR_ICMP_TYPES) | |
280 | goto out; | |
281 | ||
282 | /* Don't limit PMTU discovery. */ | |
283 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
284 | goto out; | |
285 | ||
286 | /* No rate limit on loopback */ | |
287 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 288 | goto out; |
1da177e4 LT |
289 | |
290 | /* Limit if icmp type is enabled in ratemask. */ | |
b34a95ee PE |
291 | if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) |
292 | rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit); | |
1da177e4 LT |
293 | out: |
294 | return rc; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
299 | */ | |
0388b004 | 300 | void icmp_out_count(struct net *net, unsigned char type) |
1da177e4 | 301 | { |
903fc196 | 302 | ICMPMSGOUT_INC_STATS(net, type); |
75c939bb | 303 | ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); |
1da177e4 LT |
304 | } |
305 | ||
306 | /* | |
307 | * Checksum each fragment, and on the first include the headers and final | |
308 | * checksum. | |
309 | */ | |
310 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
311 | struct sk_buff *skb) | |
312 | { | |
313 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 314 | __wsum csum; |
1da177e4 LT |
315 | |
316 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
317 | icmp_param->offset + offset, | |
318 | to, len, 0); | |
319 | ||
320 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
321 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
322 | nf_ct_attach(skb, icmp_param->skb); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
2e77d89b | 327 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 328 | { |
1e3cf683 | 329 | struct sock *sk; |
1da177e4 LT |
330 | struct sk_buff *skb; |
331 | ||
d8d1f30b | 332 | sk = icmp_sk(dev_net((*rt)->dst.dev)); |
1e3cf683 | 333 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
334 | icmp_param->data_len+icmp_param->head_len, |
335 | icmp_param->head_len, | |
1f8438a8 ED |
336 | ipc, rt, MSG_DONTWAIT) < 0) { |
337 | ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS); | |
1e3cf683 | 338 | ip_flush_pending_frames(sk); |
1f8438a8 | 339 | } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
88c7664f | 340 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 341 | __wsum csum = 0; |
1da177e4 LT |
342 | struct sk_buff *skb1; |
343 | ||
1e3cf683 | 344 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
345 | csum = csum_add(csum, skb1->csum); |
346 | } | |
347 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
348 | (char *)icmph, | |
349 | icmp_param->head_len, csum); | |
350 | icmph->checksum = csum_fold(csum); | |
351 | skb->ip_summed = CHECKSUM_NONE; | |
1e3cf683 | 352 | ip_push_pending_frames(sk); |
1da177e4 LT |
353 | } |
354 | } | |
355 | ||
356 | /* | |
357 | * Driving logic for building and sending ICMP messages. | |
358 | */ | |
359 | ||
360 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
361 | { | |
1da177e4 | 362 | struct ipcm_cookie ipc; |
511c3f92 | 363 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 364 | struct net *net = dev_net(rt->dst.dev); |
fdc0bde9 DL |
365 | struct sock *sk; |
366 | struct inet_sock *inet; | |
3ca3c68e | 367 | __be32 daddr; |
1da177e4 LT |
368 | |
369 | if (ip_options_echo(&icmp_param->replyopts, skb)) | |
f00c401b | 370 | return; |
1da177e4 | 371 | |
fdc0bde9 DL |
372 | sk = icmp_xmit_lock(net); |
373 | if (sk == NULL) | |
1da177e4 | 374 | return; |
fdc0bde9 | 375 | inet = inet_sk(sk); |
1da177e4 LT |
376 | |
377 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 378 | |
eddc9ec5 | 379 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
380 | daddr = ipc.addr = rt->rt_src; |
381 | ipc.opt = NULL; | |
2244d07b | 382 | ipc.tx_flags = 0; |
1da177e4 LT |
383 | if (icmp_param->replyopts.optlen) { |
384 | ipc.opt = &icmp_param->replyopts; | |
385 | if (ipc.opt->srr) | |
386 | daddr = icmp_param->replyopts.faddr; | |
387 | } | |
388 | { | |
5811662b CG |
389 | struct flowi fl = { .fl4_dst= daddr, |
390 | .fl4_src = rt->rt_spec_dst, | |
391 | .fl4_tos = RT_TOS(ip_hdr(skb)->tos), | |
1da177e4 | 392 | .proto = IPPROTO_ICMP }; |
beb8d13b | 393 | security_skb_classify_flow(skb, &fl); |
4a6ad7a1 | 394 | if (ip_route_output_key(net, &rt, &fl)) |
1da177e4 LT |
395 | goto out_unlock; |
396 | } | |
b34a95ee | 397 | if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, |
1da177e4 | 398 | icmp_param->data.icmph.code)) |
2e77d89b | 399 | icmp_push_reply(icmp_param, &ipc, &rt); |
1da177e4 LT |
400 | ip_rt_put(rt); |
401 | out_unlock: | |
405666db | 402 | icmp_xmit_unlock(sk); |
1da177e4 LT |
403 | } |
404 | ||
405 | ||
406 | /* | |
407 | * Send an ICMP message in response to a situation | |
408 | * | |
409 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
410 | * MAY send more (we do). | |
411 | * MUST NOT change this header information. | |
412 | * MUST NOT reply to a multicast/broadcast IP address. | |
413 | * MUST NOT reply to a multicast/broadcast MAC address. | |
414 | * MUST reply to only the first fragment. | |
415 | */ | |
416 | ||
e4883014 | 417 | void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
1da177e4 LT |
418 | { |
419 | struct iphdr *iph; | |
420 | int room; | |
421 | struct icmp_bxm icmp_param; | |
511c3f92 | 422 | struct rtable *rt = skb_rtable(skb_in); |
1da177e4 | 423 | struct ipcm_cookie ipc; |
a61ced5d | 424 | __be32 saddr; |
1da177e4 | 425 | u8 tos; |
dde1bc0e | 426 | struct net *net; |
4a6ad7a1 | 427 | struct sock *sk; |
1da177e4 LT |
428 | |
429 | if (!rt) | |
430 | goto out; | |
d8d1f30b | 431 | net = dev_net(rt->dst.dev); |
1da177e4 LT |
432 | |
433 | /* | |
434 | * Find the original header. It is expected to be valid, of course. | |
435 | * Check this, icmp_send is called from the most obscure devices | |
436 | * sometimes. | |
437 | */ | |
eddc9ec5 | 438 | iph = ip_hdr(skb_in); |
1da177e4 | 439 | |
27a884dc ACM |
440 | if ((u8 *)iph < skb_in->head || |
441 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
442 | goto out; |
443 | ||
444 | /* | |
445 | * No replies to physical multicast/broadcast | |
446 | */ | |
447 | if (skb_in->pkt_type != PACKET_HOST) | |
448 | goto out; | |
449 | ||
450 | /* | |
451 | * Now check at the protocol level | |
452 | */ | |
453 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
454 | goto out; | |
455 | ||
456 | /* | |
457 | * Only reply to fragment 0. We byte re-order the constant | |
458 | * mask for efficiency. | |
459 | */ | |
460 | if (iph->frag_off & htons(IP_OFFSET)) | |
461 | goto out; | |
462 | ||
463 | /* | |
464 | * If we send an ICMP error to an ICMP error a mess would result.. | |
465 | */ | |
466 | if (icmp_pointers[type].error) { | |
467 | /* | |
468 | * We are an error, check if we are replying to an | |
469 | * ICMP error | |
470 | */ | |
471 | if (iph->protocol == IPPROTO_ICMP) { | |
472 | u8 _inner_type, *itp; | |
473 | ||
474 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 475 | skb_network_header(skb_in) + |
1da177e4 LT |
476 | (iph->ihl << 2) + |
477 | offsetof(struct icmphdr, | |
478 | type) - | |
479 | skb_in->data, | |
480 | sizeof(_inner_type), | |
481 | &_inner_type); | |
482 | if (itp == NULL) | |
483 | goto out; | |
484 | ||
485 | /* | |
486 | * Assume any unknown ICMP type is an error. This | |
487 | * isn't specified by the RFC, but think about it.. | |
488 | */ | |
489 | if (*itp > NR_ICMP_TYPES || | |
490 | icmp_pointers[*itp].error) | |
491 | goto out; | |
492 | } | |
493 | } | |
494 | ||
fdc0bde9 DL |
495 | sk = icmp_xmit_lock(net); |
496 | if (sk == NULL) | |
1da177e4 LT |
497 | return; |
498 | ||
499 | /* | |
500 | * Construct source address and options. | |
501 | */ | |
502 | ||
503 | saddr = iph->daddr; | |
1c2fb7f9 | 504 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
505 | struct net_device *dev = NULL; |
506 | ||
685c7944 | 507 | rcu_read_lock(); |
c7537967 DM |
508 | if (rt_is_input_route(rt) && |
509 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) | |
685c7944 | 510 | dev = dev_get_by_index_rcu(net, rt->fl.iif); |
6e1d9103 | 511 | |
685c7944 | 512 | if (dev) |
6e1d9103 | 513 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
685c7944 | 514 | else |
1c2fb7f9 | 515 | saddr = 0; |
685c7944 | 516 | rcu_read_unlock(); |
1c2fb7f9 | 517 | } |
1da177e4 LT |
518 | |
519 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
520 | IPTOS_PREC_INTERNETCONTROL) : | |
521 | iph->tos; | |
522 | ||
523 | if (ip_options_echo(&icmp_param.replyopts, skb_in)) | |
fa60cf7f | 524 | goto out_unlock; |
1da177e4 LT |
525 | |
526 | ||
527 | /* | |
528 | * Prepare data for ICMP header. | |
529 | */ | |
530 | ||
531 | icmp_param.data.icmph.type = type; | |
532 | icmp_param.data.icmph.code = code; | |
533 | icmp_param.data.icmph.un.gateway = info; | |
534 | icmp_param.data.icmph.checksum = 0; | |
535 | icmp_param.skb = skb_in; | |
d56f90a7 | 536 | icmp_param.offset = skb_network_offset(skb_in); |
405666db | 537 | inet_sk(sk)->tos = tos; |
1da177e4 LT |
538 | ipc.addr = iph->saddr; |
539 | ipc.opt = &icmp_param.replyopts; | |
2244d07b | 540 | ipc.tx_flags = 0; |
1da177e4 LT |
541 | |
542 | { | |
543 | struct flowi fl = { | |
5811662b CG |
544 | .fl4_dst = icmp_param.replyopts.srr ? |
545 | icmp_param.replyopts.faddr : iph->saddr, | |
546 | .fl4_src = saddr, | |
547 | .fl4_tos = RT_TOS(tos), | |
1da177e4 | 548 | .proto = IPPROTO_ICMP, |
5811662b CG |
549 | .fl_icmp_type = type, |
550 | .fl_icmp_code = code, | |
1da177e4 | 551 | }; |
8b7817f3 HX |
552 | int err; |
553 | struct rtable *rt2; | |
554 | ||
beb8d13b | 555 | security_skb_classify_flow(skb_in, &fl); |
dde1bc0e | 556 | if (__ip_route_output_key(net, &rt, &fl)) |
8b7817f3 HX |
557 | goto out_unlock; |
558 | ||
559 | /* No need to clone since we're just using its address. */ | |
560 | rt2 = rt; | |
561 | ||
7d98ffd8 UW |
562 | if (!fl.nl_u.ip4_u.saddr) |
563 | fl.nl_u.ip4_u.saddr = rt->rt_src; | |
564 | ||
52479b62 | 565 | err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0); |
8b7817f3 HX |
566 | switch (err) { |
567 | case 0: | |
568 | if (rt != rt2) | |
569 | goto route_done; | |
570 | break; | |
571 | case -EPERM: | |
572 | rt = NULL; | |
573 | break; | |
574 | default: | |
575 | goto out_unlock; | |
576 | } | |
577 | ||
578 | if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET)) | |
af268182 | 579 | goto relookup_failed; |
8b7817f3 | 580 | |
dde1bc0e DL |
581 | if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) |
582 | err = __ip_route_output_key(net, &rt2, &fl); | |
8b7817f3 HX |
583 | else { |
584 | struct flowi fl2 = {}; | |
7fee226a | 585 | unsigned long orefdst; |
8b7817f3 HX |
586 | |
587 | fl2.fl4_dst = fl.fl4_src; | |
dde1bc0e | 588 | if (ip_route_output_key(net, &rt2, &fl2)) |
af268182 | 589 | goto relookup_failed; |
8b7817f3 HX |
590 | |
591 | /* Ugh! */ | |
7fee226a | 592 | orefdst = skb_in->_skb_refdst; /* save old refdst */ |
8b7817f3 | 593 | err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src, |
d8d1f30b | 594 | RT_TOS(tos), rt2->dst.dev); |
8b7817f3 | 595 | |
d8d1f30b | 596 | dst_release(&rt2->dst); |
511c3f92 | 597 | rt2 = skb_rtable(skb_in); |
7fee226a | 598 | skb_in->_skb_refdst = orefdst; /* restore old refdst */ |
8b7817f3 HX |
599 | } |
600 | ||
601 | if (err) | |
af268182 | 602 | goto relookup_failed; |
8b7817f3 | 603 | |
52479b62 | 604 | err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL, |
8b7817f3 | 605 | XFRM_LOOKUP_ICMP); |
af268182 HX |
606 | switch (err) { |
607 | case 0: | |
d8d1f30b | 608 | dst_release(&rt->dst); |
af268182 HX |
609 | rt = rt2; |
610 | break; | |
611 | case -EPERM: | |
612 | goto ende; | |
613 | default: | |
614 | relookup_failed: | |
8b7817f3 HX |
615 | if (!rt) |
616 | goto out_unlock; | |
af268182 | 617 | break; |
8b7817f3 | 618 | } |
1da177e4 LT |
619 | } |
620 | ||
8b7817f3 | 621 | route_done: |
b34a95ee | 622 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
623 | goto ende; |
624 | ||
625 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
626 | ||
d8d1f30b | 627 | room = dst_mtu(&rt->dst); |
1da177e4 LT |
628 | if (room > 576) |
629 | room = 576; | |
630 | room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen; | |
631 | room -= sizeof(struct icmphdr); | |
632 | ||
633 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
634 | if (icmp_param.data_len > room) | |
635 | icmp_param.data_len = room; | |
636 | icmp_param.head_len = sizeof(struct icmphdr); | |
637 | ||
2e77d89b | 638 | icmp_push_reply(&icmp_param, &ipc, &rt); |
1da177e4 LT |
639 | ende: |
640 | ip_rt_put(rt); | |
641 | out_unlock: | |
405666db | 642 | icmp_xmit_unlock(sk); |
1da177e4 LT |
643 | out:; |
644 | } | |
4bc2f18b | 645 | EXPORT_SYMBOL(icmp_send); |
1da177e4 LT |
646 | |
647 | ||
648 | /* | |
649 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
650 | */ | |
651 | ||
652 | static void icmp_unreach(struct sk_buff *skb) | |
653 | { | |
654 | struct iphdr *iph; | |
655 | struct icmphdr *icmph; | |
656 | int hash, protocol; | |
32613090 | 657 | const struct net_protocol *ipprot; |
1da177e4 | 658 | u32 info = 0; |
dde1bc0e DL |
659 | struct net *net; |
660 | ||
adf30907 | 661 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
662 | |
663 | /* | |
664 | * Incomplete header ? | |
665 | * Only checks for the IP header, there should be an | |
666 | * additional check for longer headers in upper levels. | |
667 | */ | |
668 | ||
669 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
670 | goto out_err; | |
671 | ||
88c7664f | 672 | icmph = icmp_hdr(skb); |
1da177e4 LT |
673 | iph = (struct iphdr *)skb->data; |
674 | ||
675 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
676 | goto out_err; | |
677 | ||
678 | if (icmph->type == ICMP_DEST_UNREACH) { | |
679 | switch (icmph->code & 15) { | |
680 | case ICMP_NET_UNREACH: | |
681 | case ICMP_HOST_UNREACH: | |
682 | case ICMP_PROT_UNREACH: | |
683 | case ICMP_PORT_UNREACH: | |
684 | break; | |
685 | case ICMP_FRAG_NEEDED: | |
686 | if (ipv4_config.no_pmtu_disc) { | |
673d57e7 HH |
687 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: fragmentation needed and DF set.\n", |
688 | &iph->daddr); | |
1da177e4 | 689 | } else { |
dde1bc0e | 690 | info = ip_rt_frag_needed(net, iph, |
0010e465 TT |
691 | ntohs(icmph->un.frag.mtu), |
692 | skb->dev); | |
1da177e4 LT |
693 | if (!info) |
694 | goto out; | |
695 | } | |
696 | break; | |
697 | case ICMP_SR_FAILED: | |
673d57e7 HH |
698 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: Source Route Failed.\n", |
699 | &iph->daddr); | |
1da177e4 LT |
700 | break; |
701 | default: | |
702 | break; | |
703 | } | |
704 | if (icmph->code > NR_ICMP_UNREACH) | |
705 | goto out; | |
706 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
707 | info = ntohl(icmph->un.gateway) >> 24; | |
708 | ||
709 | /* | |
710 | * Throw it at our lower layers | |
711 | * | |
712 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
713 | * header. | |
714 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
715 | * transport layer. | |
716 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
717 | * transport layer. | |
718 | */ | |
719 | ||
720 | /* | |
721 | * Check the other end isnt violating RFC 1122. Some routers send | |
722 | * bogus responses to broadcast frames. If you see this message | |
723 | * first check your netmask matches at both ends, if it does then | |
724 | * get the other vendor to fix their kit. | |
725 | */ | |
726 | ||
b34a95ee | 727 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 728 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 | 729 | if (net_ratelimit()) |
673d57e7 | 730 | printk(KERN_WARNING "%pI4 sent an invalid ICMP " |
1da177e4 | 731 | "type %u, code %u " |
673d57e7 HH |
732 | "error to a broadcast: %pI4 on %s\n", |
733 | &ip_hdr(skb)->saddr, | |
1da177e4 | 734 | icmph->type, icmph->code, |
673d57e7 | 735 | &iph->daddr, |
1da177e4 LT |
736 | skb->dev->name); |
737 | goto out; | |
738 | } | |
739 | ||
740 | /* Checkin full IP header plus 8 bytes of protocol to | |
741 | * avoid additional coding at protocol handlers. | |
742 | */ | |
743 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
744 | goto out; | |
745 | ||
746 | iph = (struct iphdr *)skb->data; | |
747 | protocol = iph->protocol; | |
748 | ||
749 | /* | |
750 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
751 | */ | |
7bc54c90 | 752 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 753 | |
1da177e4 | 754 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
755 | rcu_read_lock(); |
756 | ipprot = rcu_dereference(inet_protos[hash]); | |
757 | if (ipprot && ipprot->err_handler) | |
758 | ipprot->err_handler(skb, info); | |
759 | rcu_read_unlock(); | |
760 | ||
761 | out: | |
762 | return; | |
763 | out_err: | |
dcfc23ca | 764 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
765 | goto out; |
766 | } | |
767 | ||
768 | ||
769 | /* | |
770 | * Handle ICMP_REDIRECT. | |
771 | */ | |
772 | ||
773 | static void icmp_redirect(struct sk_buff *skb) | |
774 | { | |
775 | struct iphdr *iph; | |
1da177e4 LT |
776 | |
777 | if (skb->len < sizeof(struct iphdr)) | |
778 | goto out_err; | |
779 | ||
780 | /* | |
781 | * Get the copied header of the packet that caused the redirect | |
782 | */ | |
783 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
784 | goto out; | |
785 | ||
786 | iph = (struct iphdr *)skb->data; | |
1da177e4 | 787 | |
88c7664f | 788 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
789 | case ICMP_REDIR_NET: |
790 | case ICMP_REDIR_NETTOS: | |
791 | /* | |
792 | * As per RFC recommendations now handle it as a host redirect. | |
793 | */ | |
794 | case ICMP_REDIR_HOST: | |
795 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 796 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 797 | icmp_hdr(skb)->un.gateway, |
cef2685e | 798 | iph->saddr, skb->dev); |
1da177e4 | 799 | break; |
e905a9ed | 800 | } |
1da177e4 LT |
801 | out: |
802 | return; | |
803 | out_err: | |
dcfc23ca | 804 | ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
805 | goto out; |
806 | } | |
807 | ||
808 | /* | |
809 | * Handle ICMP_ECHO ("ping") requests. | |
810 | * | |
811 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
812 | * requests. | |
813 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
814 | * included in the reply. | |
815 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
816 | * echo requests, MUST have default=NOT. | |
817 | * See also WRT handling of options once they are done and working. | |
818 | */ | |
819 | ||
820 | static void icmp_echo(struct sk_buff *skb) | |
821 | { | |
b34a95ee PE |
822 | struct net *net; |
823 | ||
adf30907 | 824 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 825 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
826 | struct icmp_bxm icmp_param; |
827 | ||
88c7664f | 828 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
829 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
830 | icmp_param.skb = skb; | |
831 | icmp_param.offset = 0; | |
832 | icmp_param.data_len = skb->len; | |
833 | icmp_param.head_len = sizeof(struct icmphdr); | |
834 | icmp_reply(&icmp_param, skb); | |
835 | } | |
836 | } | |
837 | ||
838 | /* | |
839 | * Handle ICMP Timestamp requests. | |
840 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
841 | * SHOULD be in the kernel for minimum random latency. | |
842 | * MUST be accurate to a few minutes. | |
843 | * MUST be updated at least at 15Hz. | |
844 | */ | |
845 | static void icmp_timestamp(struct sk_buff *skb) | |
846 | { | |
f25c3d61 | 847 | struct timespec tv; |
1da177e4 LT |
848 | struct icmp_bxm icmp_param; |
849 | /* | |
850 | * Too short. | |
851 | */ | |
852 | if (skb->len < 4) | |
853 | goto out_err; | |
854 | ||
855 | /* | |
856 | * Fill in the current time as ms since midnight UT: | |
857 | */ | |
f25c3d61 YH |
858 | getnstimeofday(&tv); |
859 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + | |
860 | tv.tv_nsec / NSEC_PER_MSEC); | |
1da177e4 LT |
861 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
862 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
863 | BUG(); | |
88c7664f | 864 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
865 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
866 | icmp_param.data.icmph.code = 0; | |
867 | icmp_param.skb = skb; | |
868 | icmp_param.offset = 0; | |
869 | icmp_param.data_len = 0; | |
870 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
871 | icmp_reply(&icmp_param, skb); | |
872 | out: | |
873 | return; | |
874 | out_err: | |
adf30907 | 875 | ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
876 | goto out; |
877 | } | |
878 | ||
879 | ||
880 | /* | |
881 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
882 | * | |
883 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
884 | * ADDRESS_MASK requests if it's been configured as an address mask | |
885 | * agent. Receiving a request doesn't constitute implicit permission to | |
886 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
887 | * a way to turn the functionality on and off. Another one for sysctl(), | |
888 | * I guess. -- MS | |
889 | * | |
890 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
891 | * A router SHOULD have switch turning it on/off. | |
892 | * This switch MUST be ON by default. | |
893 | * | |
894 | * Gratuitous replies, zero-source replies are not implemented, | |
895 | * that complies with RFC. DO NOT implement them!!! All the idea | |
896 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
897 | * The problem is that it is not uncommon to have several prefixes | |
898 | * on one physical interface. Moreover, addrmask agent can even be | |
899 | * not aware of existing another prefixes. | |
900 | * If source is zero, addrmask agent cannot choose correct prefix. | |
901 | * Gratuitous mask announcements suffer from the same problem. | |
902 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
903 | * that is pretty silly. --ANK | |
904 | * | |
905 | * All these rules are so bizarre, that I removed kernel addrmask | |
906 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
907 | * any case. --ANK | |
908 | * | |
909 | * Furthermore you can do it with a usermode address agent program | |
910 | * anyway... | |
911 | */ | |
912 | ||
913 | static void icmp_address(struct sk_buff *skb) | |
914 | { | |
915 | #if 0 | |
916 | if (net_ratelimit()) | |
917 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
918 | #endif | |
919 | } | |
920 | ||
921 | /* | |
922 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
923 | * loudly if an inconsistency is found. | |
cfa087f6 | 924 | * called with rcu_read_lock() |
1da177e4 LT |
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)) | |
cfa087f6 | 935 | return; |
1da177e4 | 936 | |
cfa087f6 | 937 | in_dev = __in_dev_get_rcu(dev); |
1da177e4 | 938 | if (!in_dev) |
cfa087f6 ED |
939 | return; |
940 | ||
1da177e4 LT |
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 | } | |
1da177e4 LT |
958 | } |
959 | ||
960 | static void icmp_discard(struct sk_buff *skb) | |
961 | { | |
962 | } | |
963 | ||
964 | /* | |
965 | * Deal with incoming ICMP packets. | |
966 | */ | |
967 | int icmp_rcv(struct sk_buff *skb) | |
968 | { | |
969 | struct icmphdr *icmph; | |
511c3f92 | 970 | struct rtable *rt = skb_rtable(skb); |
d8d1f30b | 971 | struct net *net = dev_net(rt->dst.dev); |
1da177e4 | 972 | |
aebcf82c | 973 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 974 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
975 | int nh; |
976 | ||
def8b4fa | 977 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
978 | XFRM_STATE_ICMP)) |
979 | goto drop; | |
980 | ||
8b7817f3 HX |
981 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
982 | goto drop; | |
983 | ||
984 | nh = skb_network_offset(skb); | |
985 | skb_set_network_header(skb, sizeof(*icmph)); | |
986 | ||
987 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
988 | goto drop; | |
989 | ||
990 | skb_set_network_header(skb, nh); | |
991 | } | |
992 | ||
dcfc23ca | 993 | ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS); |
1da177e4 LT |
994 | |
995 | switch (skb->ip_summed) { | |
84fa7933 | 996 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 997 | if (!csum_fold(skb->csum)) |
1da177e4 | 998 | break; |
fb286bb2 | 999 | /* fall through */ |
1da177e4 | 1000 | case CHECKSUM_NONE: |
fb286bb2 HX |
1001 | skb->csum = 0; |
1002 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 1003 | goto error; |
1da177e4 LT |
1004 | } |
1005 | ||
8cf22943 HX |
1006 | if (!pskb_pull(skb, sizeof(*icmph))) |
1007 | goto error; | |
1da177e4 | 1008 | |
88c7664f | 1009 | icmph = icmp_hdr(skb); |
1da177e4 | 1010 | |
f66ac03d | 1011 | ICMPMSGIN_INC_STATS_BH(net, icmph->type); |
1da177e4 LT |
1012 | /* |
1013 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
1014 | * | |
1015 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1016 | * discarded. | |
1017 | */ | |
1018 | if (icmph->type > NR_ICMP_TYPES) | |
1019 | goto error; | |
1020 | ||
1021 | ||
1022 | /* | |
1023 | * Parse the ICMP message | |
1024 | */ | |
1025 | ||
e905a9ed | 1026 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1027 | /* |
1028 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1029 | * silently ignored (we let user decide with a sysctl). | |
1030 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1031 | * discarded if to broadcast/multicast. | |
1032 | */ | |
4c866aa7 AK |
1033 | if ((icmph->type == ICMP_ECHO || |
1034 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1035 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1036 | goto error; |
1037 | } | |
1038 | if (icmph->type != ICMP_ECHO && | |
1039 | icmph->type != ICMP_TIMESTAMP && | |
1040 | icmph->type != ICMP_ADDRESS && | |
1041 | icmph->type != ICMP_ADDRESSREPLY) { | |
1042 | goto error; | |
e905a9ed | 1043 | } |
1da177e4 LT |
1044 | } |
1045 | ||
1da177e4 LT |
1046 | icmp_pointers[icmph->type].handler(skb); |
1047 | ||
1048 | drop: | |
1049 | kfree_skb(skb); | |
1050 | return 0; | |
1051 | error: | |
dcfc23ca | 1052 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1053 | goto drop; |
1054 | } | |
1055 | ||
1056 | /* | |
1057 | * This table is the definition of how we handle ICMP. | |
1058 | */ | |
9b5b5cff | 1059 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1060 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1061 | .handler = icmp_discard, |
1062 | }, | |
1063 | [1] = { | |
1da177e4 LT |
1064 | .handler = icmp_discard, |
1065 | .error = 1, | |
1066 | }, | |
1067 | [2] = { | |
1da177e4 LT |
1068 | .handler = icmp_discard, |
1069 | .error = 1, | |
1070 | }, | |
1071 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1072 | .handler = icmp_unreach, |
1073 | .error = 1, | |
1074 | }, | |
1075 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1076 | .handler = icmp_unreach, |
1077 | .error = 1, | |
1078 | }, | |
1079 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1080 | .handler = icmp_redirect, |
1081 | .error = 1, | |
1082 | }, | |
1083 | [6] = { | |
1da177e4 LT |
1084 | .handler = icmp_discard, |
1085 | .error = 1, | |
1086 | }, | |
1087 | [7] = { | |
1da177e4 LT |
1088 | .handler = icmp_discard, |
1089 | .error = 1, | |
1090 | }, | |
1091 | [ICMP_ECHO] = { | |
1da177e4 LT |
1092 | .handler = icmp_echo, |
1093 | }, | |
1094 | [9] = { | |
1da177e4 LT |
1095 | .handler = icmp_discard, |
1096 | .error = 1, | |
1097 | }, | |
1098 | [10] = { | |
1da177e4 LT |
1099 | .handler = icmp_discard, |
1100 | .error = 1, | |
1101 | }, | |
1102 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1103 | .handler = icmp_unreach, |
1104 | .error = 1, | |
1105 | }, | |
1106 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1107 | .handler = icmp_unreach, |
1108 | .error = 1, | |
1109 | }, | |
1110 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1111 | .handler = icmp_timestamp, |
1112 | }, | |
1113 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1114 | .handler = icmp_discard, |
1115 | }, | |
1116 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1117 | .handler = icmp_discard, |
1118 | }, | |
e905a9ed | 1119 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1120 | .handler = icmp_discard, |
1121 | }, | |
1122 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1123 | .handler = icmp_address, |
1124 | }, | |
1125 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1126 | .handler = icmp_address_reply, |
1127 | }, | |
1128 | }; | |
1129 | ||
4a6ad7a1 | 1130 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1131 | { |
1da177e4 LT |
1132 | int i; |
1133 | ||
5c8cafd6 | 1134 | for_each_possible_cpu(i) |
c1e9894d | 1135 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
4a6ad7a1 DL |
1136 | kfree(net->ipv4.icmp_sk); |
1137 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1138 | } |
1da177e4 | 1139 | |
263173af | 1140 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1141 | { |
a5710d65 DL |
1142 | int i, err; |
1143 | ||
4a6ad7a1 DL |
1144 | net->ipv4.icmp_sk = |
1145 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1146 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1147 | return -ENOMEM; |
1148 | ||
a5710d65 | 1149 | for_each_possible_cpu(i) { |
1e3cf683 | 1150 | struct sock *sk; |
1da177e4 | 1151 | |
c1e9894d DL |
1152 | err = inet_ctl_sock_create(&sk, PF_INET, |
1153 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1154 | if (err < 0) |
a5710d65 | 1155 | goto fail; |
1da177e4 | 1156 | |
c1e9894d | 1157 | net->ipv4.icmp_sk[i] = sk; |
1da177e4 LT |
1158 | |
1159 | /* Enough space for 2 64K ICMP packets, including | |
1160 | * sk_buff struct overhead. | |
1161 | */ | |
1e3cf683 | 1162 | sk->sk_sndbuf = |
1da177e4 LT |
1163 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1164 | ||
b3a5b6cc ED |
1165 | /* |
1166 | * Speedup sock_wfree() | |
1167 | */ | |
1168 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
c1e9894d | 1169 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1170 | } |
a24022e1 PE |
1171 | |
1172 | /* Control parameters for ECHO replies. */ | |
1173 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1174 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1175 | ||
1176 | /* Control parameter - ignore bogus broadcast responses? */ | |
1177 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1178 | ||
1179 | /* | |
1180 | * Configurable global rate limit. | |
1181 | * | |
1182 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1183 | * bucket ratemask defines which icmp types are ratelimited by | |
1184 | * setting it's bit position. | |
1185 | * | |
1186 | * default: | |
1187 | * dest unreachable (3), source quench (4), | |
1188 | * time exceeded (11), parameter problem (12) | |
1189 | */ | |
1190 | ||
1191 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1192 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1193 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1194 | ||
a5710d65 DL |
1195 | return 0; |
1196 | ||
1197 | fail: | |
1d1c8d13 | 1198 | for_each_possible_cpu(i) |
c1e9894d | 1199 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
1d1c8d13 | 1200 | kfree(net->ipv4.icmp_sk); |
a5710d65 | 1201 | return err; |
1da177e4 LT |
1202 | } |
1203 | ||
4a6ad7a1 DL |
1204 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1205 | .init = icmp_sk_init, | |
1206 | .exit = icmp_sk_exit, | |
1207 | }; | |
1208 | ||
1209 | int __init icmp_init(void) | |
1210 | { | |
959d2726 | 1211 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 | 1212 | } |