Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Internet Control Message Protocol (ICMPv6) | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * | |
8 | * $Id: icmp.c,v 1.38 2002/02/08 03:57:19 davem Exp $ | |
9 | * | |
10 | * Based on net/ipv4/icmp.c | |
11 | * | |
12 | * RFC 1885 | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or | |
15 | * modify it under the terms of the GNU General Public License | |
16 | * as published by the Free Software Foundation; either version | |
17 | * 2 of the License, or (at your option) any later version. | |
18 | */ | |
19 | ||
20 | /* | |
21 | * Changes: | |
22 | * | |
23 | * Andi Kleen : exception handling | |
24 | * Andi Kleen add rate limits. never reply to a icmp. | |
25 | * add more length checks and other fixes. | |
26 | * yoshfuji : ensure to sent parameter problem for | |
27 | * fragments. | |
28 | * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. | |
29 | * Randy Dunlap and | |
30 | * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support | |
31 | * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data | |
32 | */ | |
33 | ||
34 | #include <linux/module.h> | |
35 | #include <linux/errno.h> | |
36 | #include <linux/types.h> | |
37 | #include <linux/socket.h> | |
38 | #include <linux/in.h> | |
39 | #include <linux/kernel.h> | |
40 | #include <linux/sched.h> | |
41 | #include <linux/sockios.h> | |
42 | #include <linux/net.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/init.h> | |
763ecff1 | 45 | #include <linux/netfilter.h> |
1da177e4 LT |
46 | |
47 | #ifdef CONFIG_SYSCTL | |
48 | #include <linux/sysctl.h> | |
49 | #endif | |
50 | ||
51 | #include <linux/inet.h> | |
52 | #include <linux/netdevice.h> | |
53 | #include <linux/icmpv6.h> | |
54 | ||
55 | #include <net/ip.h> | |
56 | #include <net/sock.h> | |
57 | ||
58 | #include <net/ipv6.h> | |
59 | #include <net/ip6_checksum.h> | |
60 | #include <net/protocol.h> | |
61 | #include <net/raw.h> | |
62 | #include <net/rawv6.h> | |
63 | #include <net/transp_v6.h> | |
64 | #include <net/ip6_route.h> | |
65 | #include <net/addrconf.h> | |
66 | #include <net/icmp.h> | |
67 | ||
68 | #include <asm/uaccess.h> | |
69 | #include <asm/system.h> | |
70 | ||
ba89966c | 71 | DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly; |
1da177e4 LT |
72 | |
73 | /* | |
74 | * The ICMP socket(s). This is the most convenient way to flow control | |
75 | * our ICMP output as well as maintain a clean interface throughout | |
76 | * all layers. All Socketless IP sends will soon be gone. | |
77 | * | |
78 | * On SMP we have one ICMP socket per-cpu. | |
79 | */ | |
80 | static DEFINE_PER_CPU(struct socket *, __icmpv6_socket) = NULL; | |
81 | #define icmpv6_socket __get_cpu_var(__icmpv6_socket) | |
82 | ||
951dbc8a | 83 | static int icmpv6_rcv(struct sk_buff **pskb); |
1da177e4 LT |
84 | |
85 | static struct inet6_protocol icmpv6_protocol = { | |
86 | .handler = icmpv6_rcv, | |
87 | .flags = INET6_PROTO_FINAL, | |
88 | }; | |
89 | ||
90 | static __inline__ int icmpv6_xmit_lock(void) | |
91 | { | |
92 | local_bh_disable(); | |
93 | ||
94 | if (unlikely(!spin_trylock(&icmpv6_socket->sk->sk_lock.slock))) { | |
95 | /* This can happen if the output path (f.e. SIT or | |
96 | * ip6ip6 tunnel) signals dst_link_failure() for an | |
97 | * outgoing ICMP6 packet. | |
98 | */ | |
99 | local_bh_enable(); | |
100 | return 1; | |
101 | } | |
102 | return 0; | |
103 | } | |
104 | ||
105 | static __inline__ void icmpv6_xmit_unlock(void) | |
106 | { | |
107 | spin_unlock_bh(&icmpv6_socket->sk->sk_lock.slock); | |
108 | } | |
109 | ||
110 | /* | |
111 | * Slightly more convenient version of icmpv6_send. | |
112 | */ | |
113 | void icmpv6_param_prob(struct sk_buff *skb, int code, int pos) | |
114 | { | |
115 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev); | |
116 | kfree_skb(skb); | |
117 | } | |
118 | ||
119 | /* | |
120 | * Figure out, may we reply to this packet with icmp error. | |
121 | * | |
122 | * We do not reply, if: | |
123 | * - it was icmp error message. | |
124 | * - it is truncated, so that it is known, that protocol is ICMPV6 | |
125 | * (i.e. in the middle of some exthdr) | |
126 | * | |
127 | * --ANK (980726) | |
128 | */ | |
129 | ||
130 | static int is_ineligible(struct sk_buff *skb) | |
131 | { | |
132 | int ptr = (u8*)(skb->nh.ipv6h+1) - skb->data; | |
133 | int len = skb->len - ptr; | |
134 | __u8 nexthdr = skb->nh.ipv6h->nexthdr; | |
135 | ||
136 | if (len < 0) | |
137 | return 1; | |
138 | ||
0d3d077c | 139 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); |
1da177e4 LT |
140 | if (ptr < 0) |
141 | return 0; | |
142 | if (nexthdr == IPPROTO_ICMPV6) { | |
143 | u8 _type, *tp; | |
144 | tp = skb_header_pointer(skb, | |
145 | ptr+offsetof(struct icmp6hdr, icmp6_type), | |
146 | sizeof(_type), &_type); | |
147 | if (tp == NULL || | |
148 | !(*tp & ICMPV6_INFOMSG_MASK)) | |
149 | return 1; | |
150 | } | |
151 | return 0; | |
152 | } | |
153 | ||
ab32ea5d | 154 | static int sysctl_icmpv6_time __read_mostly = 1*HZ; |
1da177e4 LT |
155 | |
156 | /* | |
157 | * Check the ICMP output rate limit | |
158 | */ | |
159 | static inline int icmpv6_xrlim_allow(struct sock *sk, int type, | |
160 | struct flowi *fl) | |
161 | { | |
162 | struct dst_entry *dst; | |
163 | int res = 0; | |
164 | ||
165 | /* Informational messages are not limited. */ | |
166 | if (type & ICMPV6_INFOMSG_MASK) | |
167 | return 1; | |
168 | ||
169 | /* Do not limit pmtu discovery, it would break it. */ | |
170 | if (type == ICMPV6_PKT_TOOBIG) | |
171 | return 1; | |
172 | ||
173 | /* | |
174 | * Look up the output route. | |
175 | * XXX: perhaps the expire for routing entries cloned by | |
176 | * this lookup should be more aggressive (not longer than timeout). | |
177 | */ | |
178 | dst = ip6_route_output(sk, fl); | |
179 | if (dst->error) { | |
180 | IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES); | |
181 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { | |
182 | res = 1; | |
183 | } else { | |
184 | struct rt6_info *rt = (struct rt6_info *)dst; | |
185 | int tmo = sysctl_icmpv6_time; | |
186 | ||
187 | /* Give more bandwidth to wider prefixes. */ | |
188 | if (rt->rt6i_dst.plen < 128) | |
189 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); | |
190 | ||
191 | res = xrlim_allow(dst, tmo); | |
192 | } | |
193 | dst_release(dst); | |
194 | return res; | |
195 | } | |
196 | ||
197 | /* | |
198 | * an inline helper for the "simple" if statement below | |
199 | * checks if parameter problem report is caused by an | |
200 | * unrecognized IPv6 option that has the Option Type | |
201 | * highest-order two bits set to 10 | |
202 | */ | |
203 | ||
204 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) | |
205 | { | |
206 | u8 _optval, *op; | |
207 | ||
208 | offset += skb->nh.raw - skb->data; | |
209 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); | |
210 | if (op == NULL) | |
211 | return 1; | |
212 | return (*op & 0xC0) == 0x80; | |
213 | } | |
214 | ||
215 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) | |
216 | { | |
217 | struct sk_buff *skb; | |
218 | struct icmp6hdr *icmp6h; | |
219 | int err = 0; | |
220 | ||
221 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
222 | goto out; | |
223 | ||
224 | icmp6h = (struct icmp6hdr*) skb->h.raw; | |
225 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); | |
226 | icmp6h->icmp6_cksum = 0; | |
227 | ||
228 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
229 | skb->csum = csum_partial((char *)icmp6h, | |
230 | sizeof(struct icmp6hdr), skb->csum); | |
231 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, | |
232 | &fl->fl6_dst, | |
233 | len, fl->proto, | |
234 | skb->csum); | |
235 | } else { | |
236 | u32 tmp_csum = 0; | |
237 | ||
238 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
239 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
240 | } | |
241 | ||
242 | tmp_csum = csum_partial((char *)icmp6h, | |
243 | sizeof(struct icmp6hdr), tmp_csum); | |
244 | tmp_csum = csum_ipv6_magic(&fl->fl6_src, | |
245 | &fl->fl6_dst, | |
246 | len, fl->proto, tmp_csum); | |
247 | icmp6h->icmp6_cksum = tmp_csum; | |
248 | } | |
249 | if (icmp6h->icmp6_cksum == 0) | |
250 | icmp6h->icmp6_cksum = -1; | |
251 | ip6_push_pending_frames(sk); | |
252 | out: | |
253 | return err; | |
254 | } | |
255 | ||
256 | struct icmpv6_msg { | |
257 | struct sk_buff *skb; | |
258 | int offset; | |
763ecff1 | 259 | uint8_t type; |
1da177e4 LT |
260 | }; |
261 | ||
262 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
263 | { | |
264 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
265 | struct sk_buff *org_skb = msg->skb; | |
266 | __u32 csum = 0; | |
267 | ||
268 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
269 | to, len, csum); | |
270 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
763ecff1 YK |
271 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
272 | nf_ct_attach(skb, org_skb); | |
1da177e4 LT |
273 | return 0; |
274 | } | |
275 | ||
276 | /* | |
277 | * Send an ICMP message in response to a packet in error | |
278 | */ | |
279 | void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info, | |
280 | struct net_device *dev) | |
281 | { | |
282 | struct inet6_dev *idev = NULL; | |
283 | struct ipv6hdr *hdr = skb->nh.ipv6h; | |
84427d53 YH |
284 | struct sock *sk; |
285 | struct ipv6_pinfo *np; | |
1da177e4 LT |
286 | struct in6_addr *saddr = NULL; |
287 | struct dst_entry *dst; | |
288 | struct icmp6hdr tmp_hdr; | |
289 | struct flowi fl; | |
290 | struct icmpv6_msg msg; | |
291 | int iif = 0; | |
292 | int addr_type = 0; | |
293 | int len; | |
41a1f8ea | 294 | int hlimit, tclass; |
1da177e4 LT |
295 | int err = 0; |
296 | ||
297 | if ((u8*)hdr < skb->head || (u8*)(hdr+1) > skb->tail) | |
298 | return; | |
299 | ||
300 | /* | |
301 | * Make sure we respect the rules | |
302 | * i.e. RFC 1885 2.4(e) | |
303 | * Rule (e.1) is enforced by not using icmpv6_send | |
304 | * in any code that processes icmp errors. | |
305 | */ | |
306 | addr_type = ipv6_addr_type(&hdr->daddr); | |
307 | ||
308 | if (ipv6_chk_addr(&hdr->daddr, skb->dev, 0)) | |
309 | saddr = &hdr->daddr; | |
310 | ||
311 | /* | |
312 | * Dest addr check | |
313 | */ | |
314 | ||
315 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
316 | if (type != ICMPV6_PKT_TOOBIG && | |
317 | !(type == ICMPV6_PARAMPROB && | |
318 | code == ICMPV6_UNK_OPTION && | |
319 | (opt_unrec(skb, info)))) | |
320 | return; | |
321 | ||
322 | saddr = NULL; | |
323 | } | |
324 | ||
325 | addr_type = ipv6_addr_type(&hdr->saddr); | |
326 | ||
327 | /* | |
328 | * Source addr check | |
329 | */ | |
330 | ||
331 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
332 | iif = skb->dev->ifindex; | |
333 | ||
334 | /* | |
8de3351e YH |
335 | * Must not send error if the source does not uniquely |
336 | * identify a single node (RFC2463 Section 2.4). | |
337 | * We check unspecified / multicast addresses here, | |
338 | * and anycast addresses will be checked later. | |
1da177e4 LT |
339 | */ |
340 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 341 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
342 | return; |
343 | } | |
344 | ||
345 | /* | |
346 | * Never answer to a ICMP packet. | |
347 | */ | |
348 | if (is_ineligible(skb)) { | |
64ce2073 | 349 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
350 | return; |
351 | } | |
352 | ||
353 | memset(&fl, 0, sizeof(fl)); | |
354 | fl.proto = IPPROTO_ICMPV6; | |
355 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); | |
356 | if (saddr) | |
357 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
358 | fl.oif = iif; | |
359 | fl.fl_icmp_type = type; | |
360 | fl.fl_icmp_code = code; | |
beb8d13b | 361 | security_skb_classify_flow(skb, &fl); |
1da177e4 LT |
362 | |
363 | if (icmpv6_xmit_lock()) | |
364 | return; | |
365 | ||
84427d53 YH |
366 | sk = icmpv6_socket->sk; |
367 | np = inet6_sk(sk); | |
368 | ||
1da177e4 LT |
369 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
370 | goto out; | |
371 | ||
372 | tmp_hdr.icmp6_type = type; | |
373 | tmp_hdr.icmp6_code = code; | |
374 | tmp_hdr.icmp6_cksum = 0; | |
375 | tmp_hdr.icmp6_pointer = htonl(info); | |
376 | ||
377 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) | |
378 | fl.oif = np->mcast_oif; | |
379 | ||
380 | err = ip6_dst_lookup(sk, &dst, &fl); | |
381 | if (err) | |
382 | goto out; | |
8de3351e YH |
383 | |
384 | /* | |
385 | * We won't send icmp if the destination is known | |
386 | * anycast. | |
387 | */ | |
388 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
389 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
390 | goto out_dst_release; | |
391 | } | |
392 | ||
1da177e4 | 393 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) |
e104411b | 394 | goto out; |
1da177e4 LT |
395 | |
396 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
397 | hlimit = np->mcast_hops; | |
398 | else | |
399 | hlimit = np->hop_limit; | |
400 | if (hlimit < 0) | |
401 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
402 | if (hlimit < 0) | |
403 | hlimit = ipv6_get_hoplimit(dst->dev); | |
404 | ||
e012d51c | 405 | tclass = np->tclass; |
41a1f8ea YH |
406 | if (tclass < 0) |
407 | tclass = 0; | |
408 | ||
1da177e4 LT |
409 | msg.skb = skb; |
410 | msg.offset = skb->nh.raw - skb->data; | |
763ecff1 | 411 | msg.type = type; |
1da177e4 LT |
412 | |
413 | len = skb->len - msg.offset; | |
414 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
415 | if (len < 0) { | |
64ce2073 | 416 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
417 | goto out_dst_release; |
418 | } | |
419 | ||
420 | idev = in6_dev_get(skb->dev); | |
421 | ||
422 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
423 | len + sizeof(struct icmp6hdr), | |
424 | sizeof(struct icmp6hdr), | |
41a1f8ea | 425 | hlimit, tclass, NULL, &fl, (struct rt6_info*)dst, |
1da177e4 LT |
426 | MSG_DONTWAIT); |
427 | if (err) { | |
428 | ip6_flush_pending_frames(sk); | |
429 | goto out_put; | |
430 | } | |
431 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
432 | ||
433 | if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) | |
434 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_OUTDESTUNREACHS, type - ICMPV6_DEST_UNREACH); | |
435 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); | |
436 | ||
437 | out_put: | |
438 | if (likely(idev != NULL)) | |
439 | in6_dev_put(idev); | |
440 | out_dst_release: | |
441 | dst_release(dst); | |
442 | out: | |
443 | icmpv6_xmit_unlock(); | |
444 | } | |
445 | ||
446 | static void icmpv6_echo_reply(struct sk_buff *skb) | |
447 | { | |
84427d53 | 448 | struct sock *sk; |
1da177e4 | 449 | struct inet6_dev *idev; |
84427d53 | 450 | struct ipv6_pinfo *np; |
1da177e4 LT |
451 | struct in6_addr *saddr = NULL; |
452 | struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw; | |
453 | struct icmp6hdr tmp_hdr; | |
454 | struct flowi fl; | |
455 | struct icmpv6_msg msg; | |
456 | struct dst_entry *dst; | |
457 | int err = 0; | |
458 | int hlimit; | |
41a1f8ea | 459 | int tclass; |
1da177e4 LT |
460 | |
461 | saddr = &skb->nh.ipv6h->daddr; | |
462 | ||
463 | if (!ipv6_unicast_destination(skb)) | |
464 | saddr = NULL; | |
465 | ||
466 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
467 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
468 | ||
469 | memset(&fl, 0, sizeof(fl)); | |
470 | fl.proto = IPPROTO_ICMPV6; | |
471 | ipv6_addr_copy(&fl.fl6_dst, &skb->nh.ipv6h->saddr); | |
472 | if (saddr) | |
473 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
474 | fl.oif = skb->dev->ifindex; | |
475 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; | |
beb8d13b | 476 | security_skb_classify_flow(skb, &fl); |
1da177e4 LT |
477 | |
478 | if (icmpv6_xmit_lock()) | |
479 | return; | |
480 | ||
84427d53 YH |
481 | sk = icmpv6_socket->sk; |
482 | np = inet6_sk(sk); | |
483 | ||
1da177e4 LT |
484 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
485 | fl.oif = np->mcast_oif; | |
486 | ||
487 | err = ip6_dst_lookup(sk, &dst, &fl); | |
488 | if (err) | |
489 | goto out; | |
490 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) | |
e104411b | 491 | goto out; |
1da177e4 LT |
492 | |
493 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
494 | hlimit = np->mcast_hops; | |
495 | else | |
496 | hlimit = np->hop_limit; | |
497 | if (hlimit < 0) | |
498 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
499 | if (hlimit < 0) | |
500 | hlimit = ipv6_get_hoplimit(dst->dev); | |
501 | ||
e012d51c | 502 | tclass = np->tclass; |
41a1f8ea YH |
503 | if (tclass < 0) |
504 | tclass = 0; | |
505 | ||
1da177e4 LT |
506 | idev = in6_dev_get(skb->dev); |
507 | ||
508 | msg.skb = skb; | |
509 | msg.offset = 0; | |
763ecff1 | 510 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
511 | |
512 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
41a1f8ea | 513 | sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl, |
1da177e4 LT |
514 | (struct rt6_info*)dst, MSG_DONTWAIT); |
515 | ||
516 | if (err) { | |
517 | ip6_flush_pending_frames(sk); | |
518 | goto out_put; | |
519 | } | |
520 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
521 | ||
522 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTECHOREPLIES); | |
523 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); | |
524 | ||
525 | out_put: | |
526 | if (likely(idev != NULL)) | |
527 | in6_dev_put(idev); | |
1da177e4 LT |
528 | dst_release(dst); |
529 | out: | |
530 | icmpv6_xmit_unlock(); | |
531 | } | |
532 | ||
533 | static void icmpv6_notify(struct sk_buff *skb, int type, int code, u32 info) | |
534 | { | |
535 | struct in6_addr *saddr, *daddr; | |
536 | struct inet6_protocol *ipprot; | |
537 | struct sock *sk; | |
538 | int inner_offset; | |
539 | int hash; | |
540 | u8 nexthdr; | |
541 | ||
542 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
543 | return; | |
544 | ||
545 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
546 | if (ipv6_ext_hdr(nexthdr)) { | |
547 | /* now skip over extension headers */ | |
0d3d077c | 548 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
549 | if (inner_offset<0) |
550 | return; | |
551 | } else { | |
552 | inner_offset = sizeof(struct ipv6hdr); | |
553 | } | |
554 | ||
555 | /* Checkin header including 8 bytes of inner protocol header. */ | |
556 | if (!pskb_may_pull(skb, inner_offset+8)) | |
557 | return; | |
558 | ||
559 | saddr = &skb->nh.ipv6h->saddr; | |
560 | daddr = &skb->nh.ipv6h->daddr; | |
561 | ||
562 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. | |
563 | Without this we will not able f.e. to make source routed | |
564 | pmtu discovery. | |
565 | Corresponding argument (opt) to notifiers is already added. | |
566 | --ANK (980726) | |
567 | */ | |
568 | ||
569 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
570 | ||
571 | rcu_read_lock(); | |
572 | ipprot = rcu_dereference(inet6_protos[hash]); | |
573 | if (ipprot && ipprot->err_handler) | |
574 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
575 | rcu_read_unlock(); | |
576 | ||
577 | read_lock(&raw_v6_lock); | |
578 | if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) { | |
0bd1b59b | 579 | while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr, |
2dac4b96 | 580 | IP6CB(skb)->iif))) { |
1da177e4 LT |
581 | rawv6_err(sk, skb, NULL, type, code, inner_offset, info); |
582 | sk = sk_next(sk); | |
583 | } | |
584 | } | |
585 | read_unlock(&raw_v6_lock); | |
586 | } | |
587 | ||
588 | /* | |
589 | * Handle icmp messages | |
590 | */ | |
591 | ||
951dbc8a | 592 | static int icmpv6_rcv(struct sk_buff **pskb) |
1da177e4 LT |
593 | { |
594 | struct sk_buff *skb = *pskb; | |
595 | struct net_device *dev = skb->dev; | |
596 | struct inet6_dev *idev = __in6_dev_get(dev); | |
597 | struct in6_addr *saddr, *daddr; | |
598 | struct ipv6hdr *orig_hdr; | |
599 | struct icmp6hdr *hdr; | |
600 | int type; | |
601 | ||
602 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS); | |
603 | ||
604 | saddr = &skb->nh.ipv6h->saddr; | |
605 | daddr = &skb->nh.ipv6h->daddr; | |
606 | ||
607 | /* Perform checksum. */ | |
fb286bb2 | 608 | switch (skb->ip_summed) { |
84fa7933 | 609 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
610 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
611 | skb->csum)) | |
612 | break; | |
613 | /* fall through */ | |
614 | case CHECKSUM_NONE: | |
615 | skb->csum = ~csum_ipv6_magic(saddr, daddr, skb->len, | |
616 | IPPROTO_ICMPV6, 0); | |
617 | if (__skb_checksum_complete(skb)) { | |
46b86a2d | 618 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [" NIP6_FMT " > " NIP6_FMT "]\n", |
64ce2073 | 619 | NIP6(*saddr), NIP6(*daddr)); |
1da177e4 LT |
620 | goto discard_it; |
621 | } | |
622 | } | |
623 | ||
624 | if (!pskb_pull(skb, sizeof(struct icmp6hdr))) | |
625 | goto discard_it; | |
626 | ||
627 | hdr = (struct icmp6hdr *) skb->h.raw; | |
628 | ||
629 | type = hdr->icmp6_type; | |
630 | ||
631 | if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) | |
632 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INDESTUNREACHS, type - ICMPV6_DEST_UNREACH); | |
633 | else if (type >= ICMPV6_ECHO_REQUEST && type <= NDISC_REDIRECT) | |
634 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INECHOS, type - ICMPV6_ECHO_REQUEST); | |
635 | ||
636 | switch (type) { | |
637 | case ICMPV6_ECHO_REQUEST: | |
638 | icmpv6_echo_reply(skb); | |
639 | break; | |
640 | ||
641 | case ICMPV6_ECHO_REPLY: | |
642 | /* we couldn't care less */ | |
643 | break; | |
644 | ||
645 | case ICMPV6_PKT_TOOBIG: | |
646 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
647 | standard destination cache. Seems, only "advanced" | |
648 | destination cache will allow to solve this problem | |
649 | --ANK (980726) | |
650 | */ | |
651 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
652 | goto discard_it; | |
653 | hdr = (struct icmp6hdr *) skb->h.raw; | |
654 | orig_hdr = (struct ipv6hdr *) (hdr + 1); | |
655 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
656 | ntohl(hdr->icmp6_mtu)); | |
657 | ||
658 | /* | |
659 | * Drop through to notify | |
660 | */ | |
661 | ||
662 | case ICMPV6_DEST_UNREACH: | |
663 | case ICMPV6_TIME_EXCEED: | |
664 | case ICMPV6_PARAMPROB: | |
665 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
666 | break; | |
667 | ||
668 | case NDISC_ROUTER_SOLICITATION: | |
669 | case NDISC_ROUTER_ADVERTISEMENT: | |
670 | case NDISC_NEIGHBOUR_SOLICITATION: | |
671 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
672 | case NDISC_REDIRECT: | |
673 | ndisc_rcv(skb); | |
674 | break; | |
675 | ||
676 | case ICMPV6_MGM_QUERY: | |
677 | igmp6_event_query(skb); | |
678 | break; | |
679 | ||
680 | case ICMPV6_MGM_REPORT: | |
681 | igmp6_event_report(skb); | |
682 | break; | |
683 | ||
684 | case ICMPV6_MGM_REDUCTION: | |
685 | case ICMPV6_NI_QUERY: | |
686 | case ICMPV6_NI_REPLY: | |
687 | case ICMPV6_MLD2_REPORT: | |
688 | case ICMPV6_DHAAD_REQUEST: | |
689 | case ICMPV6_DHAAD_REPLY: | |
690 | case ICMPV6_MOBILE_PREFIX_SOL: | |
691 | case ICMPV6_MOBILE_PREFIX_ADV: | |
692 | break; | |
693 | ||
694 | default: | |
64ce2073 | 695 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
696 | |
697 | /* informational */ | |
698 | if (type & ICMPV6_INFOMSG_MASK) | |
699 | break; | |
700 | ||
701 | /* | |
702 | * error of unknown type. | |
703 | * must pass to upper level | |
704 | */ | |
705 | ||
706 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
707 | }; | |
708 | kfree_skb(skb); | |
709 | return 0; | |
710 | ||
711 | discard_it: | |
712 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS); | |
713 | kfree_skb(skb); | |
714 | return 0; | |
715 | } | |
716 | ||
640c41c7 IM |
717 | /* |
718 | * Special lock-class for __icmpv6_socket: | |
719 | */ | |
720 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
721 | ||
1da177e4 LT |
722 | int __init icmpv6_init(struct net_proto_family *ops) |
723 | { | |
724 | struct sock *sk; | |
725 | int err, i, j; | |
726 | ||
6f912042 | 727 | for_each_possible_cpu(i) { |
1da177e4 LT |
728 | err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, |
729 | &per_cpu(__icmpv6_socket, i)); | |
730 | if (err < 0) { | |
731 | printk(KERN_ERR | |
732 | "Failed to initialize the ICMP6 control socket " | |
733 | "(err %d).\n", | |
734 | err); | |
735 | goto fail; | |
736 | } | |
737 | ||
738 | sk = per_cpu(__icmpv6_socket, i)->sk; | |
739 | sk->sk_allocation = GFP_ATOMIC; | |
640c41c7 IM |
740 | /* |
741 | * Split off their lock-class, because sk->sk_dst_lock | |
742 | * gets used from softirqs, which is safe for | |
743 | * __icmpv6_socket (because those never get directly used | |
744 | * via userspace syscalls), but unsafe for normal sockets. | |
745 | */ | |
746 | lockdep_set_class(&sk->sk_dst_lock, | |
747 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
748 | |
749 | /* Enough space for 2 64K ICMP packets, including | |
750 | * sk_buff struct overhead. | |
751 | */ | |
752 | sk->sk_sndbuf = | |
753 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
754 | ||
755 | sk->sk_prot->unhash(sk); | |
756 | } | |
757 | ||
758 | ||
759 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) { | |
760 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
761 | err = -EAGAIN; | |
762 | goto fail; | |
763 | } | |
764 | ||
765 | return 0; | |
766 | ||
767 | fail: | |
768 | for (j = 0; j < i; j++) { | |
769 | if (!cpu_possible(j)) | |
770 | continue; | |
771 | sock_release(per_cpu(__icmpv6_socket, j)); | |
772 | } | |
773 | ||
774 | return err; | |
775 | } | |
776 | ||
777 | void icmpv6_cleanup(void) | |
778 | { | |
779 | int i; | |
780 | ||
6f912042 | 781 | for_each_possible_cpu(i) { |
1da177e4 LT |
782 | sock_release(per_cpu(__icmpv6_socket, i)); |
783 | } | |
784 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); | |
785 | } | |
786 | ||
9b5b5cff | 787 | static const struct icmp6_err { |
1da177e4 LT |
788 | int err; |
789 | int fatal; | |
790 | } tab_unreach[] = { | |
791 | { /* NOROUTE */ | |
792 | .err = ENETUNREACH, | |
793 | .fatal = 0, | |
794 | }, | |
795 | { /* ADM_PROHIBITED */ | |
796 | .err = EACCES, | |
797 | .fatal = 1, | |
798 | }, | |
799 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
800 | .err = EHOSTUNREACH, | |
801 | .fatal = 0, | |
802 | }, | |
803 | { /* ADDR_UNREACH */ | |
804 | .err = EHOSTUNREACH, | |
805 | .fatal = 0, | |
806 | }, | |
807 | { /* PORT_UNREACH */ | |
808 | .err = ECONNREFUSED, | |
809 | .fatal = 1, | |
810 | }, | |
811 | }; | |
812 | ||
813 | int icmpv6_err_convert(int type, int code, int *err) | |
814 | { | |
815 | int fatal = 0; | |
816 | ||
817 | *err = EPROTO; | |
818 | ||
819 | switch (type) { | |
820 | case ICMPV6_DEST_UNREACH: | |
821 | fatal = 1; | |
822 | if (code <= ICMPV6_PORT_UNREACH) { | |
823 | *err = tab_unreach[code].err; | |
824 | fatal = tab_unreach[code].fatal; | |
825 | } | |
826 | break; | |
827 | ||
828 | case ICMPV6_PKT_TOOBIG: | |
829 | *err = EMSGSIZE; | |
830 | break; | |
831 | ||
832 | case ICMPV6_PARAMPROB: | |
833 | *err = EPROTO; | |
834 | fatal = 1; | |
835 | break; | |
836 | ||
837 | case ICMPV6_TIME_EXCEED: | |
838 | *err = EHOSTUNREACH; | |
839 | break; | |
840 | }; | |
841 | ||
842 | return fatal; | |
843 | } | |
844 | ||
845 | #ifdef CONFIG_SYSCTL | |
846 | ctl_table ipv6_icmp_table[] = { | |
847 | { | |
848 | .ctl_name = NET_IPV6_ICMP_RATELIMIT, | |
849 | .procname = "ratelimit", | |
850 | .data = &sysctl_icmpv6_time, | |
851 | .maxlen = sizeof(int), | |
852 | .mode = 0644, | |
853 | .proc_handler = &proc_dointvec | |
854 | }, | |
855 | { .ctl_name = 0 }, | |
856 | }; | |
857 | #endif | |
858 |