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; | |
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 | }; | |
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 | ||
235 | /* | |
236 | * Check transmit rate limitation for given message. | |
237 | * The rate information is held in the destination cache now. | |
238 | * This function is generic and could be used for other purposes | |
239 | * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov. | |
240 | * | |
241 | * Note that the same dst_entry fields are modified by functions in | |
242 | * route.c too, but these work for packet destinations while xrlim_allow | |
243 | * works for icmp destinations. This means the rate limiting information | |
244 | * for one "ip object" is shared - and these ICMPs are twice limited: | |
245 | * by source and by destination. | |
246 | * | |
247 | * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate | |
248 | * SHOULD allow setting of rate limits | |
249 | * | |
250 | * Shared between ICMPv4 and ICMPv6. | |
251 | */ | |
252 | #define XRLIM_BURST_FACTOR 6 | |
253 | int xrlim_allow(struct dst_entry *dst, int timeout) | |
254 | { | |
69a73829 | 255 | unsigned long now, token = dst->rate_tokens; |
1da177e4 LT |
256 | int rc = 0; |
257 | ||
258 | now = jiffies; | |
69a73829 | 259 | token += now - dst->rate_last; |
1da177e4 | 260 | dst->rate_last = now; |
69a73829 ED |
261 | if (token > XRLIM_BURST_FACTOR * timeout) |
262 | token = XRLIM_BURST_FACTOR * timeout; | |
263 | if (token >= timeout) { | |
264 | token -= timeout; | |
1da177e4 LT |
265 | rc = 1; |
266 | } | |
69a73829 | 267 | dst->rate_tokens = token; |
1da177e4 LT |
268 | return rc; |
269 | } | |
270 | ||
b34a95ee PE |
271 | static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt, |
272 | int type, int code) | |
1da177e4 LT |
273 | { |
274 | struct dst_entry *dst = &rt->u.dst; | |
275 | int rc = 1; | |
276 | ||
277 | if (type > NR_ICMP_TYPES) | |
278 | goto out; | |
279 | ||
280 | /* Don't limit PMTU discovery. */ | |
281 | if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) | |
282 | goto out; | |
283 | ||
284 | /* No rate limit on loopback */ | |
285 | if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) | |
e905a9ed | 286 | goto out; |
1da177e4 LT |
287 | |
288 | /* Limit if icmp type is enabled in ratemask. */ | |
b34a95ee PE |
289 | if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) |
290 | rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit); | |
1da177e4 LT |
291 | out: |
292 | return rc; | |
293 | } | |
294 | ||
295 | /* | |
296 | * Maintain the counters used in the SNMP statistics for outgoing ICMP | |
297 | */ | |
0388b004 | 298 | void icmp_out_count(struct net *net, unsigned char type) |
1da177e4 | 299 | { |
903fc196 | 300 | ICMPMSGOUT_INC_STATS(net, type); |
75c939bb | 301 | ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS); |
1da177e4 LT |
302 | } |
303 | ||
304 | /* | |
305 | * Checksum each fragment, and on the first include the headers and final | |
306 | * checksum. | |
307 | */ | |
308 | static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd, | |
309 | struct sk_buff *skb) | |
310 | { | |
311 | struct icmp_bxm *icmp_param = (struct icmp_bxm *)from; | |
5f92a738 | 312 | __wsum csum; |
1da177e4 LT |
313 | |
314 | csum = skb_copy_and_csum_bits(icmp_param->skb, | |
315 | icmp_param->offset + offset, | |
316 | to, len, 0); | |
317 | ||
318 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
319 | if (icmp_pointers[icmp_param->data.icmph.type].error) | |
320 | nf_ct_attach(skb, icmp_param->skb); | |
321 | return 0; | |
322 | } | |
323 | ||
324 | static void icmp_push_reply(struct icmp_bxm *icmp_param, | |
2e77d89b | 325 | struct ipcm_cookie *ipc, struct rtable **rt) |
1da177e4 | 326 | { |
1e3cf683 | 327 | struct sock *sk; |
1da177e4 LT |
328 | struct sk_buff *skb; |
329 | ||
2e77d89b | 330 | sk = icmp_sk(dev_net((*rt)->u.dst.dev)); |
1e3cf683 | 331 | if (ip_append_data(sk, icmp_glue_bits, icmp_param, |
e905a9ed YH |
332 | icmp_param->data_len+icmp_param->head_len, |
333 | icmp_param->head_len, | |
1f8438a8 ED |
334 | ipc, rt, MSG_DONTWAIT) < 0) { |
335 | ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS); | |
1e3cf683 | 336 | ip_flush_pending_frames(sk); |
1f8438a8 | 337 | } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
88c7664f | 338 | struct icmphdr *icmph = icmp_hdr(skb); |
d3bc23e7 | 339 | __wsum csum = 0; |
1da177e4 LT |
340 | struct sk_buff *skb1; |
341 | ||
1e3cf683 | 342 | skb_queue_walk(&sk->sk_write_queue, skb1) { |
1da177e4 LT |
343 | csum = csum_add(csum, skb1->csum); |
344 | } | |
345 | csum = csum_partial_copy_nocheck((void *)&icmp_param->data, | |
346 | (char *)icmph, | |
347 | icmp_param->head_len, csum); | |
348 | icmph->checksum = csum_fold(csum); | |
349 | skb->ip_summed = CHECKSUM_NONE; | |
1e3cf683 | 350 | ip_push_pending_frames(sk); |
1da177e4 LT |
351 | } |
352 | } | |
353 | ||
354 | /* | |
355 | * Driving logic for building and sending ICMP messages. | |
356 | */ | |
357 | ||
358 | static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb) | |
359 | { | |
1da177e4 | 360 | struct ipcm_cookie ipc; |
511c3f92 | 361 | struct rtable *rt = skb_rtable(skb); |
c346dca1 | 362 | struct net *net = dev_net(rt->u.dst.dev); |
fdc0bde9 DL |
363 | struct sock *sk; |
364 | struct inet_sock *inet; | |
3ca3c68e | 365 | __be32 daddr; |
1da177e4 LT |
366 | |
367 | if (ip_options_echo(&icmp_param->replyopts, skb)) | |
f00c401b | 368 | return; |
1da177e4 | 369 | |
fdc0bde9 DL |
370 | sk = icmp_xmit_lock(net); |
371 | if (sk == NULL) | |
1da177e4 | 372 | return; |
fdc0bde9 | 373 | inet = inet_sk(sk); |
1da177e4 LT |
374 | |
375 | icmp_param->data.icmph.checksum = 0; | |
1da177e4 | 376 | |
eddc9ec5 | 377 | inet->tos = ip_hdr(skb)->tos; |
1da177e4 LT |
378 | daddr = ipc.addr = rt->rt_src; |
379 | ipc.opt = NULL; | |
51f31cab | 380 | ipc.shtx.flags = 0; |
1da177e4 LT |
381 | if (icmp_param->replyopts.optlen) { |
382 | ipc.opt = &icmp_param->replyopts; | |
383 | if (ipc.opt->srr) | |
384 | daddr = icmp_param->replyopts.faddr; | |
385 | } | |
386 | { | |
387 | struct flowi fl = { .nl_u = { .ip4_u = | |
388 | { .daddr = daddr, | |
389 | .saddr = rt->rt_spec_dst, | |
eddc9ec5 | 390 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
1da177e4 | 391 | .proto = IPPROTO_ICMP }; |
beb8d13b | 392 | security_skb_classify_flow(skb, &fl); |
4a6ad7a1 | 393 | if (ip_route_output_key(net, &rt, &fl)) |
1da177e4 LT |
394 | goto out_unlock; |
395 | } | |
b34a95ee | 396 | if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type, |
1da177e4 | 397 | icmp_param->data.icmph.code)) |
2e77d89b | 398 | icmp_push_reply(icmp_param, &ipc, &rt); |
1da177e4 LT |
399 | ip_rt_put(rt); |
400 | out_unlock: | |
405666db | 401 | icmp_xmit_unlock(sk); |
1da177e4 LT |
402 | } |
403 | ||
404 | ||
405 | /* | |
406 | * Send an ICMP message in response to a situation | |
407 | * | |
408 | * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. | |
409 | * MAY send more (we do). | |
410 | * MUST NOT change this header information. | |
411 | * MUST NOT reply to a multicast/broadcast IP address. | |
412 | * MUST NOT reply to a multicast/broadcast MAC address. | |
413 | * MUST reply to only the first fragment. | |
414 | */ | |
415 | ||
e4883014 | 416 | void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) |
1da177e4 LT |
417 | { |
418 | struct iphdr *iph; | |
419 | int room; | |
420 | struct icmp_bxm icmp_param; | |
511c3f92 | 421 | struct rtable *rt = skb_rtable(skb_in); |
1da177e4 | 422 | struct ipcm_cookie ipc; |
a61ced5d | 423 | __be32 saddr; |
1da177e4 | 424 | u8 tos; |
dde1bc0e | 425 | struct net *net; |
4a6ad7a1 | 426 | struct sock *sk; |
1da177e4 LT |
427 | |
428 | if (!rt) | |
429 | goto out; | |
c346dca1 | 430 | net = dev_net(rt->u.dst.dev); |
1da177e4 LT |
431 | |
432 | /* | |
433 | * Find the original header. It is expected to be valid, of course. | |
434 | * Check this, icmp_send is called from the most obscure devices | |
435 | * sometimes. | |
436 | */ | |
eddc9ec5 | 437 | iph = ip_hdr(skb_in); |
1da177e4 | 438 | |
27a884dc ACM |
439 | if ((u8 *)iph < skb_in->head || |
440 | (skb_in->network_header + sizeof(*iph)) > skb_in->tail) | |
1da177e4 LT |
441 | goto out; |
442 | ||
443 | /* | |
444 | * No replies to physical multicast/broadcast | |
445 | */ | |
446 | if (skb_in->pkt_type != PACKET_HOST) | |
447 | goto out; | |
448 | ||
449 | /* | |
450 | * Now check at the protocol level | |
451 | */ | |
452 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) | |
453 | goto out; | |
454 | ||
455 | /* | |
456 | * Only reply to fragment 0. We byte re-order the constant | |
457 | * mask for efficiency. | |
458 | */ | |
459 | if (iph->frag_off & htons(IP_OFFSET)) | |
460 | goto out; | |
461 | ||
462 | /* | |
463 | * If we send an ICMP error to an ICMP error a mess would result.. | |
464 | */ | |
465 | if (icmp_pointers[type].error) { | |
466 | /* | |
467 | * We are an error, check if we are replying to an | |
468 | * ICMP error | |
469 | */ | |
470 | if (iph->protocol == IPPROTO_ICMP) { | |
471 | u8 _inner_type, *itp; | |
472 | ||
473 | itp = skb_header_pointer(skb_in, | |
d56f90a7 | 474 | skb_network_header(skb_in) + |
1da177e4 LT |
475 | (iph->ihl << 2) + |
476 | offsetof(struct icmphdr, | |
477 | type) - | |
478 | skb_in->data, | |
479 | sizeof(_inner_type), | |
480 | &_inner_type); | |
481 | if (itp == NULL) | |
482 | goto out; | |
483 | ||
484 | /* | |
485 | * Assume any unknown ICMP type is an error. This | |
486 | * isn't specified by the RFC, but think about it.. | |
487 | */ | |
488 | if (*itp > NR_ICMP_TYPES || | |
489 | icmp_pointers[*itp].error) | |
490 | goto out; | |
491 | } | |
492 | } | |
493 | ||
fdc0bde9 DL |
494 | sk = icmp_xmit_lock(net); |
495 | if (sk == NULL) | |
1da177e4 LT |
496 | return; |
497 | ||
498 | /* | |
499 | * Construct source address and options. | |
500 | */ | |
501 | ||
502 | saddr = iph->daddr; | |
1c2fb7f9 | 503 | if (!(rt->rt_flags & RTCF_LOCAL)) { |
6e1d9103 PM |
504 | struct net_device *dev = NULL; |
505 | ||
685c7944 | 506 | rcu_read_lock(); |
a24022e1 | 507 | if (rt->fl.iif && |
b34a95ee | 508 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) |
685c7944 | 509 | dev = dev_get_by_index_rcu(net, rt->fl.iif); |
6e1d9103 | 510 | |
685c7944 | 511 | if (dev) |
6e1d9103 | 512 | saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); |
685c7944 | 513 | else |
1c2fb7f9 | 514 | saddr = 0; |
685c7944 | 515 | rcu_read_unlock(); |
1c2fb7f9 | 516 | } |
1da177e4 LT |
517 | |
518 | tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) | | |
519 | IPTOS_PREC_INTERNETCONTROL) : | |
520 | iph->tos; | |
521 | ||
522 | if (ip_options_echo(&icmp_param.replyopts, skb_in)) | |
fa60cf7f | 523 | goto out_unlock; |
1da177e4 LT |
524 | |
525 | ||
526 | /* | |
527 | * Prepare data for ICMP header. | |
528 | */ | |
529 | ||
530 | icmp_param.data.icmph.type = type; | |
531 | icmp_param.data.icmph.code = code; | |
532 | icmp_param.data.icmph.un.gateway = info; | |
533 | icmp_param.data.icmph.checksum = 0; | |
534 | icmp_param.skb = skb_in; | |
d56f90a7 | 535 | icmp_param.offset = skb_network_offset(skb_in); |
405666db | 536 | inet_sk(sk)->tos = tos; |
1da177e4 LT |
537 | ipc.addr = iph->saddr; |
538 | ipc.opt = &icmp_param.replyopts; | |
51f31cab | 539 | ipc.shtx.flags = 0; |
1da177e4 LT |
540 | |
541 | { | |
542 | struct flowi fl = { | |
543 | .nl_u = { | |
544 | .ip4_u = { | |
545 | .daddr = icmp_param.replyopts.srr ? | |
546 | icmp_param.replyopts.faddr : | |
547 | iph->saddr, | |
548 | .saddr = saddr, | |
549 | .tos = RT_TOS(tos) | |
550 | } | |
551 | }, | |
552 | .proto = IPPROTO_ICMP, | |
553 | .uli_u = { | |
554 | .icmpt = { | |
555 | .type = type, | |
556 | .code = code | |
557 | } | |
558 | } | |
559 | }; | |
8b7817f3 HX |
560 | int err; |
561 | struct rtable *rt2; | |
562 | ||
beb8d13b | 563 | security_skb_classify_flow(skb_in, &fl); |
dde1bc0e | 564 | if (__ip_route_output_key(net, &rt, &fl)) |
8b7817f3 HX |
565 | goto out_unlock; |
566 | ||
567 | /* No need to clone since we're just using its address. */ | |
568 | rt2 = rt; | |
569 | ||
52479b62 | 570 | err = xfrm_lookup(net, (struct dst_entry **)&rt, &fl, NULL, 0); |
8b7817f3 HX |
571 | switch (err) { |
572 | case 0: | |
573 | if (rt != rt2) | |
574 | goto route_done; | |
575 | break; | |
576 | case -EPERM: | |
577 | rt = NULL; | |
578 | break; | |
579 | default: | |
580 | goto out_unlock; | |
581 | } | |
582 | ||
583 | if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET)) | |
af268182 | 584 | goto relookup_failed; |
8b7817f3 | 585 | |
dde1bc0e DL |
586 | if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL) |
587 | err = __ip_route_output_key(net, &rt2, &fl); | |
8b7817f3 HX |
588 | else { |
589 | struct flowi fl2 = {}; | |
7fee226a | 590 | unsigned long orefdst; |
8b7817f3 HX |
591 | |
592 | fl2.fl4_dst = fl.fl4_src; | |
dde1bc0e | 593 | if (ip_route_output_key(net, &rt2, &fl2)) |
af268182 | 594 | goto relookup_failed; |
8b7817f3 HX |
595 | |
596 | /* Ugh! */ | |
7fee226a | 597 | orefdst = skb_in->_skb_refdst; /* save old refdst */ |
8b7817f3 HX |
598 | err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src, |
599 | RT_TOS(tos), rt2->u.dst.dev); | |
600 | ||
601 | dst_release(&rt2->u.dst); | |
511c3f92 | 602 | rt2 = skb_rtable(skb_in); |
7fee226a | 603 | skb_in->_skb_refdst = orefdst; /* restore old refdst */ |
8b7817f3 HX |
604 | } |
605 | ||
606 | if (err) | |
af268182 | 607 | goto relookup_failed; |
8b7817f3 | 608 | |
52479b62 | 609 | err = xfrm_lookup(net, (struct dst_entry **)&rt2, &fl, NULL, |
8b7817f3 | 610 | XFRM_LOOKUP_ICMP); |
af268182 HX |
611 | switch (err) { |
612 | case 0: | |
613 | dst_release(&rt->u.dst); | |
614 | rt = rt2; | |
615 | break; | |
616 | case -EPERM: | |
617 | goto ende; | |
618 | default: | |
619 | relookup_failed: | |
8b7817f3 HX |
620 | if (!rt) |
621 | goto out_unlock; | |
af268182 | 622 | break; |
8b7817f3 | 623 | } |
1da177e4 LT |
624 | } |
625 | ||
8b7817f3 | 626 | route_done: |
b34a95ee | 627 | if (!icmpv4_xrlim_allow(net, rt, type, code)) |
1da177e4 LT |
628 | goto ende; |
629 | ||
630 | /* RFC says return as much as we can without exceeding 576 bytes. */ | |
631 | ||
632 | room = dst_mtu(&rt->u.dst); | |
633 | if (room > 576) | |
634 | room = 576; | |
635 | room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen; | |
636 | room -= sizeof(struct icmphdr); | |
637 | ||
638 | icmp_param.data_len = skb_in->len - icmp_param.offset; | |
639 | if (icmp_param.data_len > room) | |
640 | icmp_param.data_len = room; | |
641 | icmp_param.head_len = sizeof(struct icmphdr); | |
642 | ||
2e77d89b | 643 | icmp_push_reply(&icmp_param, &ipc, &rt); |
1da177e4 LT |
644 | ende: |
645 | ip_rt_put(rt); | |
646 | out_unlock: | |
405666db | 647 | icmp_xmit_unlock(sk); |
1da177e4 LT |
648 | out:; |
649 | } | |
650 | ||
651 | ||
652 | /* | |
653 | * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH. | |
654 | */ | |
655 | ||
656 | static void icmp_unreach(struct sk_buff *skb) | |
657 | { | |
658 | struct iphdr *iph; | |
659 | struct icmphdr *icmph; | |
660 | int hash, protocol; | |
32613090 | 661 | const struct net_protocol *ipprot; |
1da177e4 | 662 | u32 info = 0; |
dde1bc0e DL |
663 | struct net *net; |
664 | ||
adf30907 | 665 | net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
666 | |
667 | /* | |
668 | * Incomplete header ? | |
669 | * Only checks for the IP header, there should be an | |
670 | * additional check for longer headers in upper levels. | |
671 | */ | |
672 | ||
673 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
674 | goto out_err; | |
675 | ||
88c7664f | 676 | icmph = icmp_hdr(skb); |
1da177e4 LT |
677 | iph = (struct iphdr *)skb->data; |
678 | ||
679 | if (iph->ihl < 5) /* Mangled header, drop. */ | |
680 | goto out_err; | |
681 | ||
682 | if (icmph->type == ICMP_DEST_UNREACH) { | |
683 | switch (icmph->code & 15) { | |
684 | case ICMP_NET_UNREACH: | |
685 | case ICMP_HOST_UNREACH: | |
686 | case ICMP_PROT_UNREACH: | |
687 | case ICMP_PORT_UNREACH: | |
688 | break; | |
689 | case ICMP_FRAG_NEEDED: | |
690 | if (ipv4_config.no_pmtu_disc) { | |
673d57e7 HH |
691 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: fragmentation needed and DF set.\n", |
692 | &iph->daddr); | |
1da177e4 | 693 | } else { |
dde1bc0e | 694 | info = ip_rt_frag_needed(net, iph, |
0010e465 TT |
695 | ntohs(icmph->un.frag.mtu), |
696 | skb->dev); | |
1da177e4 LT |
697 | if (!info) |
698 | goto out; | |
699 | } | |
700 | break; | |
701 | case ICMP_SR_FAILED: | |
673d57e7 HH |
702 | LIMIT_NETDEBUG(KERN_INFO "ICMP: %pI4: Source Route Failed.\n", |
703 | &iph->daddr); | |
1da177e4 LT |
704 | break; |
705 | default: | |
706 | break; | |
707 | } | |
708 | if (icmph->code > NR_ICMP_UNREACH) | |
709 | goto out; | |
710 | } else if (icmph->type == ICMP_PARAMETERPROB) | |
711 | info = ntohl(icmph->un.gateway) >> 24; | |
712 | ||
713 | /* | |
714 | * Throw it at our lower layers | |
715 | * | |
716 | * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed | |
717 | * header. | |
718 | * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the | |
719 | * transport layer. | |
720 | * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to | |
721 | * transport layer. | |
722 | */ | |
723 | ||
724 | /* | |
725 | * Check the other end isnt violating RFC 1122. Some routers send | |
726 | * bogus responses to broadcast frames. If you see this message | |
727 | * first check your netmask matches at both ends, if it does then | |
728 | * get the other vendor to fix their kit. | |
729 | */ | |
730 | ||
b34a95ee | 731 | if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses && |
dde1bc0e | 732 | inet_addr_type(net, iph->daddr) == RTN_BROADCAST) { |
1da177e4 | 733 | if (net_ratelimit()) |
673d57e7 | 734 | printk(KERN_WARNING "%pI4 sent an invalid ICMP " |
1da177e4 | 735 | "type %u, code %u " |
673d57e7 HH |
736 | "error to a broadcast: %pI4 on %s\n", |
737 | &ip_hdr(skb)->saddr, | |
1da177e4 | 738 | icmph->type, icmph->code, |
673d57e7 | 739 | &iph->daddr, |
1da177e4 LT |
740 | skb->dev->name); |
741 | goto out; | |
742 | } | |
743 | ||
744 | /* Checkin full IP header plus 8 bytes of protocol to | |
745 | * avoid additional coding at protocol handlers. | |
746 | */ | |
747 | if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) | |
748 | goto out; | |
749 | ||
750 | iph = (struct iphdr *)skb->data; | |
751 | protocol = iph->protocol; | |
752 | ||
753 | /* | |
754 | * Deliver ICMP message to raw sockets. Pretty useless feature? | |
755 | */ | |
7bc54c90 | 756 | raw_icmp_error(skb, protocol, info); |
1da177e4 | 757 | |
1da177e4 | 758 | hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 LT |
759 | rcu_read_lock(); |
760 | ipprot = rcu_dereference(inet_protos[hash]); | |
761 | if (ipprot && ipprot->err_handler) | |
762 | ipprot->err_handler(skb, info); | |
763 | rcu_read_unlock(); | |
764 | ||
765 | out: | |
766 | return; | |
767 | out_err: | |
dcfc23ca | 768 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
769 | goto out; |
770 | } | |
771 | ||
772 | ||
773 | /* | |
774 | * Handle ICMP_REDIRECT. | |
775 | */ | |
776 | ||
777 | static void icmp_redirect(struct sk_buff *skb) | |
778 | { | |
779 | struct iphdr *iph; | |
1da177e4 LT |
780 | |
781 | if (skb->len < sizeof(struct iphdr)) | |
782 | goto out_err; | |
783 | ||
784 | /* | |
785 | * Get the copied header of the packet that caused the redirect | |
786 | */ | |
787 | if (!pskb_may_pull(skb, sizeof(struct iphdr))) | |
788 | goto out; | |
789 | ||
790 | iph = (struct iphdr *)skb->data; | |
1da177e4 | 791 | |
88c7664f | 792 | switch (icmp_hdr(skb)->code & 7) { |
1da177e4 LT |
793 | case ICMP_REDIR_NET: |
794 | case ICMP_REDIR_NETTOS: | |
795 | /* | |
796 | * As per RFC recommendations now handle it as a host redirect. | |
797 | */ | |
798 | case ICMP_REDIR_HOST: | |
799 | case ICMP_REDIR_HOSTTOS: | |
eddc9ec5 | 800 | ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr, |
88c7664f | 801 | icmp_hdr(skb)->un.gateway, |
cef2685e | 802 | iph->saddr, skb->dev); |
1da177e4 | 803 | break; |
e905a9ed | 804 | } |
1da177e4 LT |
805 | out: |
806 | return; | |
807 | out_err: | |
dcfc23ca | 808 | ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
809 | goto out; |
810 | } | |
811 | ||
812 | /* | |
813 | * Handle ICMP_ECHO ("ping") requests. | |
814 | * | |
815 | * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo | |
816 | * requests. | |
817 | * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be | |
818 | * included in the reply. | |
819 | * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring | |
820 | * echo requests, MUST have default=NOT. | |
821 | * See also WRT handling of options once they are done and working. | |
822 | */ | |
823 | ||
824 | static void icmp_echo(struct sk_buff *skb) | |
825 | { | |
b34a95ee PE |
826 | struct net *net; |
827 | ||
adf30907 | 828 | net = dev_net(skb_dst(skb)->dev); |
b34a95ee | 829 | if (!net->ipv4.sysctl_icmp_echo_ignore_all) { |
1da177e4 LT |
830 | struct icmp_bxm icmp_param; |
831 | ||
88c7664f | 832 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
833 | icmp_param.data.icmph.type = ICMP_ECHOREPLY; |
834 | icmp_param.skb = skb; | |
835 | icmp_param.offset = 0; | |
836 | icmp_param.data_len = skb->len; | |
837 | icmp_param.head_len = sizeof(struct icmphdr); | |
838 | icmp_reply(&icmp_param, skb); | |
839 | } | |
840 | } | |
841 | ||
842 | /* | |
843 | * Handle ICMP Timestamp requests. | |
844 | * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. | |
845 | * SHOULD be in the kernel for minimum random latency. | |
846 | * MUST be accurate to a few minutes. | |
847 | * MUST be updated at least at 15Hz. | |
848 | */ | |
849 | static void icmp_timestamp(struct sk_buff *skb) | |
850 | { | |
f25c3d61 | 851 | struct timespec tv; |
1da177e4 LT |
852 | struct icmp_bxm icmp_param; |
853 | /* | |
854 | * Too short. | |
855 | */ | |
856 | if (skb->len < 4) | |
857 | goto out_err; | |
858 | ||
859 | /* | |
860 | * Fill in the current time as ms since midnight UT: | |
861 | */ | |
f25c3d61 YH |
862 | getnstimeofday(&tv); |
863 | icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + | |
864 | tv.tv_nsec / NSEC_PER_MSEC); | |
1da177e4 LT |
865 | icmp_param.data.times[2] = icmp_param.data.times[1]; |
866 | if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4)) | |
867 | BUG(); | |
88c7664f | 868 | icmp_param.data.icmph = *icmp_hdr(skb); |
1da177e4 LT |
869 | icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY; |
870 | icmp_param.data.icmph.code = 0; | |
871 | icmp_param.skb = skb; | |
872 | icmp_param.offset = 0; | |
873 | icmp_param.data_len = 0; | |
874 | icmp_param.head_len = sizeof(struct icmphdr) + 12; | |
875 | icmp_reply(&icmp_param, skb); | |
876 | out: | |
877 | return; | |
878 | out_err: | |
adf30907 | 879 | ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); |
1da177e4 LT |
880 | goto out; |
881 | } | |
882 | ||
883 | ||
884 | /* | |
885 | * Handle ICMP_ADDRESS_MASK requests. (RFC950) | |
886 | * | |
887 | * RFC1122 (3.2.2.9). A host MUST only send replies to | |
888 | * ADDRESS_MASK requests if it's been configured as an address mask | |
889 | * agent. Receiving a request doesn't constitute implicit permission to | |
890 | * act as one. Of course, implementing this correctly requires (SHOULD) | |
891 | * a way to turn the functionality on and off. Another one for sysctl(), | |
892 | * I guess. -- MS | |
893 | * | |
894 | * RFC1812 (4.3.3.9). A router MUST implement it. | |
895 | * A router SHOULD have switch turning it on/off. | |
896 | * This switch MUST be ON by default. | |
897 | * | |
898 | * Gratuitous replies, zero-source replies are not implemented, | |
899 | * that complies with RFC. DO NOT implement them!!! All the idea | |
900 | * of broadcast addrmask replies as specified in RFC950 is broken. | |
901 | * The problem is that it is not uncommon to have several prefixes | |
902 | * on one physical interface. Moreover, addrmask agent can even be | |
903 | * not aware of existing another prefixes. | |
904 | * If source is zero, addrmask agent cannot choose correct prefix. | |
905 | * Gratuitous mask announcements suffer from the same problem. | |
906 | * RFC1812 explains it, but still allows to use ADDRMASK, | |
907 | * that is pretty silly. --ANK | |
908 | * | |
909 | * All these rules are so bizarre, that I removed kernel addrmask | |
910 | * support at all. It is wrong, it is obsolete, nobody uses it in | |
911 | * any case. --ANK | |
912 | * | |
913 | * Furthermore you can do it with a usermode address agent program | |
914 | * anyway... | |
915 | */ | |
916 | ||
917 | static void icmp_address(struct sk_buff *skb) | |
918 | { | |
919 | #if 0 | |
920 | if (net_ratelimit()) | |
921 | printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n"); | |
922 | #endif | |
923 | } | |
924 | ||
925 | /* | |
926 | * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain | |
927 | * loudly if an inconsistency is found. | |
928 | */ | |
929 | ||
930 | static void icmp_address_reply(struct sk_buff *skb) | |
931 | { | |
511c3f92 | 932 | struct rtable *rt = skb_rtable(skb); |
1da177e4 LT |
933 | struct net_device *dev = skb->dev; |
934 | struct in_device *in_dev; | |
935 | struct in_ifaddr *ifa; | |
936 | ||
937 | if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC)) | |
938 | goto out; | |
939 | ||
940 | in_dev = in_dev_get(dev); | |
941 | if (!in_dev) | |
942 | goto out; | |
943 | rcu_read_lock(); | |
944 | if (in_dev->ifa_list && | |
945 | IN_DEV_LOG_MARTIANS(in_dev) && | |
946 | IN_DEV_FORWARD(in_dev)) { | |
a144ea4b | 947 | __be32 _mask, *mp; |
1da177e4 LT |
948 | |
949 | mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask); | |
09a62660 | 950 | BUG_ON(mp == NULL); |
1da177e4 LT |
951 | for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) { |
952 | if (*mp == ifa->ifa_mask && | |
953 | inet_ifa_match(rt->rt_src, ifa)) | |
954 | break; | |
955 | } | |
956 | if (!ifa && net_ratelimit()) { | |
673d57e7 HH |
957 | printk(KERN_INFO "Wrong address mask %pI4 from %s/%pI4\n", |
958 | mp, dev->name, &rt->rt_src); | |
1da177e4 LT |
959 | } |
960 | } | |
961 | rcu_read_unlock(); | |
962 | in_dev_put(in_dev); | |
963 | out:; | |
964 | } | |
965 | ||
966 | static void icmp_discard(struct sk_buff *skb) | |
967 | { | |
968 | } | |
969 | ||
970 | /* | |
971 | * Deal with incoming ICMP packets. | |
972 | */ | |
973 | int icmp_rcv(struct sk_buff *skb) | |
974 | { | |
975 | struct icmphdr *icmph; | |
511c3f92 | 976 | struct rtable *rt = skb_rtable(skb); |
fd54d716 | 977 | struct net *net = dev_net(rt->u.dst.dev); |
1da177e4 | 978 | |
aebcf82c | 979 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 980 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
981 | int nh; |
982 | ||
def8b4fa | 983 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
984 | XFRM_STATE_ICMP)) |
985 | goto drop; | |
986 | ||
8b7817f3 HX |
987 | if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr))) |
988 | goto drop; | |
989 | ||
990 | nh = skb_network_offset(skb); | |
991 | skb_set_network_header(skb, sizeof(*icmph)); | |
992 | ||
993 | if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
994 | goto drop; | |
995 | ||
996 | skb_set_network_header(skb, nh); | |
997 | } | |
998 | ||
dcfc23ca | 999 | ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS); |
1da177e4 LT |
1000 | |
1001 | switch (skb->ip_summed) { | |
84fa7933 | 1002 | case CHECKSUM_COMPLETE: |
d3bc23e7 | 1003 | if (!csum_fold(skb->csum)) |
1da177e4 | 1004 | break; |
fb286bb2 | 1005 | /* fall through */ |
1da177e4 | 1006 | case CHECKSUM_NONE: |
fb286bb2 HX |
1007 | skb->csum = 0; |
1008 | if (__skb_checksum_complete(skb)) | |
1da177e4 | 1009 | goto error; |
1da177e4 LT |
1010 | } |
1011 | ||
8cf22943 HX |
1012 | if (!pskb_pull(skb, sizeof(*icmph))) |
1013 | goto error; | |
1da177e4 | 1014 | |
88c7664f | 1015 | icmph = icmp_hdr(skb); |
1da177e4 | 1016 | |
f66ac03d | 1017 | ICMPMSGIN_INC_STATS_BH(net, icmph->type); |
1da177e4 LT |
1018 | /* |
1019 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
1020 | * | |
1021 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
1022 | * discarded. | |
1023 | */ | |
1024 | if (icmph->type > NR_ICMP_TYPES) | |
1025 | goto error; | |
1026 | ||
1027 | ||
1028 | /* | |
1029 | * Parse the ICMP message | |
1030 | */ | |
1031 | ||
e905a9ed | 1032 | if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) { |
1da177e4 LT |
1033 | /* |
1034 | * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be | |
1035 | * silently ignored (we let user decide with a sysctl). | |
1036 | * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently | |
1037 | * discarded if to broadcast/multicast. | |
1038 | */ | |
4c866aa7 AK |
1039 | if ((icmph->type == ICMP_ECHO || |
1040 | icmph->type == ICMP_TIMESTAMP) && | |
b34a95ee | 1041 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts) { |
1da177e4 LT |
1042 | goto error; |
1043 | } | |
1044 | if (icmph->type != ICMP_ECHO && | |
1045 | icmph->type != ICMP_TIMESTAMP && | |
1046 | icmph->type != ICMP_ADDRESS && | |
1047 | icmph->type != ICMP_ADDRESSREPLY) { | |
1048 | goto error; | |
e905a9ed | 1049 | } |
1da177e4 LT |
1050 | } |
1051 | ||
1da177e4 LT |
1052 | icmp_pointers[icmph->type].handler(skb); |
1053 | ||
1054 | drop: | |
1055 | kfree_skb(skb); | |
1056 | return 0; | |
1057 | error: | |
dcfc23ca | 1058 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
1059 | goto drop; |
1060 | } | |
1061 | ||
1062 | /* | |
1063 | * This table is the definition of how we handle ICMP. | |
1064 | */ | |
9b5b5cff | 1065 | static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = { |
1da177e4 | 1066 | [ICMP_ECHOREPLY] = { |
1da177e4 LT |
1067 | .handler = icmp_discard, |
1068 | }, | |
1069 | [1] = { | |
1da177e4 LT |
1070 | .handler = icmp_discard, |
1071 | .error = 1, | |
1072 | }, | |
1073 | [2] = { | |
1da177e4 LT |
1074 | .handler = icmp_discard, |
1075 | .error = 1, | |
1076 | }, | |
1077 | [ICMP_DEST_UNREACH] = { | |
1da177e4 LT |
1078 | .handler = icmp_unreach, |
1079 | .error = 1, | |
1080 | }, | |
1081 | [ICMP_SOURCE_QUENCH] = { | |
1da177e4 LT |
1082 | .handler = icmp_unreach, |
1083 | .error = 1, | |
1084 | }, | |
1085 | [ICMP_REDIRECT] = { | |
1da177e4 LT |
1086 | .handler = icmp_redirect, |
1087 | .error = 1, | |
1088 | }, | |
1089 | [6] = { | |
1da177e4 LT |
1090 | .handler = icmp_discard, |
1091 | .error = 1, | |
1092 | }, | |
1093 | [7] = { | |
1da177e4 LT |
1094 | .handler = icmp_discard, |
1095 | .error = 1, | |
1096 | }, | |
1097 | [ICMP_ECHO] = { | |
1da177e4 LT |
1098 | .handler = icmp_echo, |
1099 | }, | |
1100 | [9] = { | |
1da177e4 LT |
1101 | .handler = icmp_discard, |
1102 | .error = 1, | |
1103 | }, | |
1104 | [10] = { | |
1da177e4 LT |
1105 | .handler = icmp_discard, |
1106 | .error = 1, | |
1107 | }, | |
1108 | [ICMP_TIME_EXCEEDED] = { | |
1da177e4 LT |
1109 | .handler = icmp_unreach, |
1110 | .error = 1, | |
1111 | }, | |
1112 | [ICMP_PARAMETERPROB] = { | |
1da177e4 LT |
1113 | .handler = icmp_unreach, |
1114 | .error = 1, | |
1115 | }, | |
1116 | [ICMP_TIMESTAMP] = { | |
1da177e4 LT |
1117 | .handler = icmp_timestamp, |
1118 | }, | |
1119 | [ICMP_TIMESTAMPREPLY] = { | |
1da177e4 LT |
1120 | .handler = icmp_discard, |
1121 | }, | |
1122 | [ICMP_INFO_REQUEST] = { | |
1da177e4 LT |
1123 | .handler = icmp_discard, |
1124 | }, | |
e905a9ed | 1125 | [ICMP_INFO_REPLY] = { |
1da177e4 LT |
1126 | .handler = icmp_discard, |
1127 | }, | |
1128 | [ICMP_ADDRESS] = { | |
1da177e4 LT |
1129 | .handler = icmp_address, |
1130 | }, | |
1131 | [ICMP_ADDRESSREPLY] = { | |
1da177e4 LT |
1132 | .handler = icmp_address_reply, |
1133 | }, | |
1134 | }; | |
1135 | ||
4a6ad7a1 | 1136 | static void __net_exit icmp_sk_exit(struct net *net) |
1da177e4 | 1137 | { |
1da177e4 LT |
1138 | int i; |
1139 | ||
5c8cafd6 | 1140 | for_each_possible_cpu(i) |
c1e9894d | 1141 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
4a6ad7a1 DL |
1142 | kfree(net->ipv4.icmp_sk); |
1143 | net->ipv4.icmp_sk = NULL; | |
a5710d65 | 1144 | } |
1da177e4 | 1145 | |
263173af | 1146 | static int __net_init icmp_sk_init(struct net *net) |
a5710d65 | 1147 | { |
a5710d65 DL |
1148 | int i, err; |
1149 | ||
4a6ad7a1 DL |
1150 | net->ipv4.icmp_sk = |
1151 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
1152 | if (net->ipv4.icmp_sk == NULL) | |
79c91159 DL |
1153 | return -ENOMEM; |
1154 | ||
a5710d65 | 1155 | for_each_possible_cpu(i) { |
1e3cf683 | 1156 | struct sock *sk; |
1da177e4 | 1157 | |
c1e9894d DL |
1158 | err = inet_ctl_sock_create(&sk, PF_INET, |
1159 | SOCK_RAW, IPPROTO_ICMP, net); | |
1da177e4 | 1160 | if (err < 0) |
a5710d65 | 1161 | goto fail; |
1da177e4 | 1162 | |
c1e9894d | 1163 | net->ipv4.icmp_sk[i] = sk; |
1da177e4 LT |
1164 | |
1165 | /* Enough space for 2 64K ICMP packets, including | |
1166 | * sk_buff struct overhead. | |
1167 | */ | |
1e3cf683 | 1168 | sk->sk_sndbuf = |
1da177e4 LT |
1169 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); |
1170 | ||
b3a5b6cc ED |
1171 | /* |
1172 | * Speedup sock_wfree() | |
1173 | */ | |
1174 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
c1e9894d | 1175 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT; |
1da177e4 | 1176 | } |
a24022e1 PE |
1177 | |
1178 | /* Control parameters for ECHO replies. */ | |
1179 | net->ipv4.sysctl_icmp_echo_ignore_all = 0; | |
1180 | net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1; | |
1181 | ||
1182 | /* Control parameter - ignore bogus broadcast responses? */ | |
1183 | net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1; | |
1184 | ||
1185 | /* | |
1186 | * Configurable global rate limit. | |
1187 | * | |
1188 | * ratelimit defines tokens/packet consumed for dst->rate_token | |
1189 | * bucket ratemask defines which icmp types are ratelimited by | |
1190 | * setting it's bit position. | |
1191 | * | |
1192 | * default: | |
1193 | * dest unreachable (3), source quench (4), | |
1194 | * time exceeded (11), parameter problem (12) | |
1195 | */ | |
1196 | ||
1197 | net->ipv4.sysctl_icmp_ratelimit = 1 * HZ; | |
1198 | net->ipv4.sysctl_icmp_ratemask = 0x1818; | |
1199 | net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0; | |
1200 | ||
a5710d65 DL |
1201 | return 0; |
1202 | ||
1203 | fail: | |
1d1c8d13 | 1204 | for_each_possible_cpu(i) |
c1e9894d | 1205 | inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]); |
1d1c8d13 | 1206 | kfree(net->ipv4.icmp_sk); |
a5710d65 | 1207 | return err; |
1da177e4 LT |
1208 | } |
1209 | ||
4a6ad7a1 DL |
1210 | static struct pernet_operations __net_initdata icmp_sk_ops = { |
1211 | .init = icmp_sk_init, | |
1212 | .exit = icmp_sk_exit, | |
1213 | }; | |
1214 | ||
1215 | int __init icmp_init(void) | |
1216 | { | |
959d2726 | 1217 | return register_pernet_subsys(&icmp_sk_ops); |
4a6ad7a1 DL |
1218 | } |
1219 | ||
1da177e4 LT |
1220 | EXPORT_SYMBOL(icmp_err_convert); |
1221 | EXPORT_SYMBOL(icmp_send); | |
1da177e4 | 1222 | EXPORT_SYMBOL(xrlim_allow); |