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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 | ||
154 | static int sysctl_icmpv6_time = 1*HZ; | |
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; | |
361 | ||
362 | if (icmpv6_xmit_lock()) | |
363 | return; | |
364 | ||
84427d53 YH |
365 | sk = icmpv6_socket->sk; |
366 | np = inet6_sk(sk); | |
367 | ||
1da177e4 LT |
368 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
369 | goto out; | |
370 | ||
371 | tmp_hdr.icmp6_type = type; | |
372 | tmp_hdr.icmp6_code = code; | |
373 | tmp_hdr.icmp6_cksum = 0; | |
374 | tmp_hdr.icmp6_pointer = htonl(info); | |
375 | ||
376 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) | |
377 | fl.oif = np->mcast_oif; | |
378 | ||
379 | err = ip6_dst_lookup(sk, &dst, &fl); | |
380 | if (err) | |
381 | goto out; | |
8de3351e YH |
382 | |
383 | /* | |
384 | * We won't send icmp if the destination is known | |
385 | * anycast. | |
386 | */ | |
387 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
388 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
389 | goto out_dst_release; | |
390 | } | |
391 | ||
1da177e4 | 392 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) |
e104411b | 393 | goto out; |
1da177e4 LT |
394 | |
395 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
396 | hlimit = np->mcast_hops; | |
397 | else | |
398 | hlimit = np->hop_limit; | |
399 | if (hlimit < 0) | |
400 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
401 | if (hlimit < 0) | |
402 | hlimit = ipv6_get_hoplimit(dst->dev); | |
403 | ||
41a1f8ea YH |
404 | tclass = np->cork.tclass; |
405 | if (tclass < 0) | |
406 | tclass = 0; | |
407 | ||
1da177e4 LT |
408 | msg.skb = skb; |
409 | msg.offset = skb->nh.raw - skb->data; | |
763ecff1 | 410 | msg.type = type; |
1da177e4 LT |
411 | |
412 | len = skb->len - msg.offset; | |
413 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
414 | if (len < 0) { | |
64ce2073 | 415 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
416 | goto out_dst_release; |
417 | } | |
418 | ||
419 | idev = in6_dev_get(skb->dev); | |
420 | ||
421 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
422 | len + sizeof(struct icmp6hdr), | |
423 | sizeof(struct icmp6hdr), | |
41a1f8ea | 424 | hlimit, tclass, NULL, &fl, (struct rt6_info*)dst, |
1da177e4 LT |
425 | MSG_DONTWAIT); |
426 | if (err) { | |
427 | ip6_flush_pending_frames(sk); | |
428 | goto out_put; | |
429 | } | |
430 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
431 | ||
432 | if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) | |
433 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_OUTDESTUNREACHS, type - ICMPV6_DEST_UNREACH); | |
434 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); | |
435 | ||
436 | out_put: | |
437 | if (likely(idev != NULL)) | |
438 | in6_dev_put(idev); | |
439 | out_dst_release: | |
440 | dst_release(dst); | |
441 | out: | |
442 | icmpv6_xmit_unlock(); | |
443 | } | |
444 | ||
445 | static void icmpv6_echo_reply(struct sk_buff *skb) | |
446 | { | |
84427d53 | 447 | struct sock *sk; |
1da177e4 | 448 | struct inet6_dev *idev; |
84427d53 | 449 | struct ipv6_pinfo *np; |
1da177e4 LT |
450 | struct in6_addr *saddr = NULL; |
451 | struct icmp6hdr *icmph = (struct icmp6hdr *) skb->h.raw; | |
452 | struct icmp6hdr tmp_hdr; | |
453 | struct flowi fl; | |
454 | struct icmpv6_msg msg; | |
455 | struct dst_entry *dst; | |
456 | int err = 0; | |
457 | int hlimit; | |
41a1f8ea | 458 | int tclass; |
1da177e4 LT |
459 | |
460 | saddr = &skb->nh.ipv6h->daddr; | |
461 | ||
462 | if (!ipv6_unicast_destination(skb)) | |
463 | saddr = NULL; | |
464 | ||
465 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
466 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
467 | ||
468 | memset(&fl, 0, sizeof(fl)); | |
469 | fl.proto = IPPROTO_ICMPV6; | |
470 | ipv6_addr_copy(&fl.fl6_dst, &skb->nh.ipv6h->saddr); | |
471 | if (saddr) | |
472 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
473 | fl.oif = skb->dev->ifindex; | |
474 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; | |
475 | ||
476 | if (icmpv6_xmit_lock()) | |
477 | return; | |
478 | ||
84427d53 YH |
479 | sk = icmpv6_socket->sk; |
480 | np = inet6_sk(sk); | |
481 | ||
1da177e4 LT |
482 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
483 | fl.oif = np->mcast_oif; | |
484 | ||
485 | err = ip6_dst_lookup(sk, &dst, &fl); | |
486 | if (err) | |
487 | goto out; | |
488 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) | |
e104411b | 489 | goto out; |
1da177e4 LT |
490 | |
491 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
492 | hlimit = np->mcast_hops; | |
493 | else | |
494 | hlimit = np->hop_limit; | |
495 | if (hlimit < 0) | |
496 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
497 | if (hlimit < 0) | |
498 | hlimit = ipv6_get_hoplimit(dst->dev); | |
499 | ||
41a1f8ea YH |
500 | tclass = np->cork.tclass; |
501 | if (tclass < 0) | |
502 | tclass = 0; | |
503 | ||
1da177e4 LT |
504 | idev = in6_dev_get(skb->dev); |
505 | ||
506 | msg.skb = skb; | |
507 | msg.offset = 0; | |
763ecff1 | 508 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
509 | |
510 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
41a1f8ea | 511 | sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl, |
1da177e4 LT |
512 | (struct rt6_info*)dst, MSG_DONTWAIT); |
513 | ||
514 | if (err) { | |
515 | ip6_flush_pending_frames(sk); | |
516 | goto out_put; | |
517 | } | |
518 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
519 | ||
520 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTECHOREPLIES); | |
521 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS); | |
522 | ||
523 | out_put: | |
524 | if (likely(idev != NULL)) | |
525 | in6_dev_put(idev); | |
1da177e4 LT |
526 | dst_release(dst); |
527 | out: | |
528 | icmpv6_xmit_unlock(); | |
529 | } | |
530 | ||
531 | static void icmpv6_notify(struct sk_buff *skb, int type, int code, u32 info) | |
532 | { | |
533 | struct in6_addr *saddr, *daddr; | |
534 | struct inet6_protocol *ipprot; | |
535 | struct sock *sk; | |
536 | int inner_offset; | |
537 | int hash; | |
538 | u8 nexthdr; | |
539 | ||
540 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
541 | return; | |
542 | ||
543 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
544 | if (ipv6_ext_hdr(nexthdr)) { | |
545 | /* now skip over extension headers */ | |
0d3d077c | 546 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
547 | if (inner_offset<0) |
548 | return; | |
549 | } else { | |
550 | inner_offset = sizeof(struct ipv6hdr); | |
551 | } | |
552 | ||
553 | /* Checkin header including 8 bytes of inner protocol header. */ | |
554 | if (!pskb_may_pull(skb, inner_offset+8)) | |
555 | return; | |
556 | ||
557 | saddr = &skb->nh.ipv6h->saddr; | |
558 | daddr = &skb->nh.ipv6h->daddr; | |
559 | ||
560 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. | |
561 | Without this we will not able f.e. to make source routed | |
562 | pmtu discovery. | |
563 | Corresponding argument (opt) to notifiers is already added. | |
564 | --ANK (980726) | |
565 | */ | |
566 | ||
567 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
568 | ||
569 | rcu_read_lock(); | |
570 | ipprot = rcu_dereference(inet6_protos[hash]); | |
571 | if (ipprot && ipprot->err_handler) | |
572 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
573 | rcu_read_unlock(); | |
574 | ||
575 | read_lock(&raw_v6_lock); | |
576 | if ((sk = sk_head(&raw_v6_htable[hash])) != NULL) { | |
0bd1b59b | 577 | while((sk = __raw_v6_lookup(sk, nexthdr, daddr, saddr, |
2dac4b96 | 578 | IP6CB(skb)->iif))) { |
1da177e4 LT |
579 | rawv6_err(sk, skb, NULL, type, code, inner_offset, info); |
580 | sk = sk_next(sk); | |
581 | } | |
582 | } | |
583 | read_unlock(&raw_v6_lock); | |
584 | } | |
585 | ||
586 | /* | |
587 | * Handle icmp messages | |
588 | */ | |
589 | ||
951dbc8a | 590 | static int icmpv6_rcv(struct sk_buff **pskb) |
1da177e4 LT |
591 | { |
592 | struct sk_buff *skb = *pskb; | |
593 | struct net_device *dev = skb->dev; | |
594 | struct inet6_dev *idev = __in6_dev_get(dev); | |
595 | struct in6_addr *saddr, *daddr; | |
596 | struct ipv6hdr *orig_hdr; | |
597 | struct icmp6hdr *hdr; | |
598 | int type; | |
599 | ||
600 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS); | |
601 | ||
602 | saddr = &skb->nh.ipv6h->saddr; | |
603 | daddr = &skb->nh.ipv6h->daddr; | |
604 | ||
605 | /* Perform checksum. */ | |
fb286bb2 HX |
606 | switch (skb->ip_summed) { |
607 | case CHECKSUM_HW: | |
608 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, | |
609 | skb->csum)) | |
610 | break; | |
611 | /* fall through */ | |
612 | case CHECKSUM_NONE: | |
613 | skb->csum = ~csum_ipv6_magic(saddr, daddr, skb->len, | |
614 | IPPROTO_ICMPV6, 0); | |
615 | if (__skb_checksum_complete(skb)) { | |
46b86a2d | 616 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [" NIP6_FMT " > " NIP6_FMT "]\n", |
64ce2073 | 617 | NIP6(*saddr), NIP6(*daddr)); |
1da177e4 LT |
618 | goto discard_it; |
619 | } | |
620 | } | |
621 | ||
622 | if (!pskb_pull(skb, sizeof(struct icmp6hdr))) | |
623 | goto discard_it; | |
624 | ||
625 | hdr = (struct icmp6hdr *) skb->h.raw; | |
626 | ||
627 | type = hdr->icmp6_type; | |
628 | ||
629 | if (type >= ICMPV6_DEST_UNREACH && type <= ICMPV6_PARAMPROB) | |
630 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INDESTUNREACHS, type - ICMPV6_DEST_UNREACH); | |
631 | else if (type >= ICMPV6_ECHO_REQUEST && type <= NDISC_REDIRECT) | |
632 | ICMP6_INC_STATS_OFFSET_BH(idev, ICMP6_MIB_INECHOS, type - ICMPV6_ECHO_REQUEST); | |
633 | ||
634 | switch (type) { | |
635 | case ICMPV6_ECHO_REQUEST: | |
636 | icmpv6_echo_reply(skb); | |
637 | break; | |
638 | ||
639 | case ICMPV6_ECHO_REPLY: | |
640 | /* we couldn't care less */ | |
641 | break; | |
642 | ||
643 | case ICMPV6_PKT_TOOBIG: | |
644 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
645 | standard destination cache. Seems, only "advanced" | |
646 | destination cache will allow to solve this problem | |
647 | --ANK (980726) | |
648 | */ | |
649 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
650 | goto discard_it; | |
651 | hdr = (struct icmp6hdr *) skb->h.raw; | |
652 | orig_hdr = (struct ipv6hdr *) (hdr + 1); | |
653 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
654 | ntohl(hdr->icmp6_mtu)); | |
655 | ||
656 | /* | |
657 | * Drop through to notify | |
658 | */ | |
659 | ||
660 | case ICMPV6_DEST_UNREACH: | |
661 | case ICMPV6_TIME_EXCEED: | |
662 | case ICMPV6_PARAMPROB: | |
663 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
664 | break; | |
665 | ||
666 | case NDISC_ROUTER_SOLICITATION: | |
667 | case NDISC_ROUTER_ADVERTISEMENT: | |
668 | case NDISC_NEIGHBOUR_SOLICITATION: | |
669 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
670 | case NDISC_REDIRECT: | |
671 | ndisc_rcv(skb); | |
672 | break; | |
673 | ||
674 | case ICMPV6_MGM_QUERY: | |
675 | igmp6_event_query(skb); | |
676 | break; | |
677 | ||
678 | case ICMPV6_MGM_REPORT: | |
679 | igmp6_event_report(skb); | |
680 | break; | |
681 | ||
682 | case ICMPV6_MGM_REDUCTION: | |
683 | case ICMPV6_NI_QUERY: | |
684 | case ICMPV6_NI_REPLY: | |
685 | case ICMPV6_MLD2_REPORT: | |
686 | case ICMPV6_DHAAD_REQUEST: | |
687 | case ICMPV6_DHAAD_REPLY: | |
688 | case ICMPV6_MOBILE_PREFIX_SOL: | |
689 | case ICMPV6_MOBILE_PREFIX_ADV: | |
690 | break; | |
691 | ||
692 | default: | |
64ce2073 | 693 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
694 | |
695 | /* informational */ | |
696 | if (type & ICMPV6_INFOMSG_MASK) | |
697 | break; | |
698 | ||
699 | /* | |
700 | * error of unknown type. | |
701 | * must pass to upper level | |
702 | */ | |
703 | ||
704 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
705 | }; | |
706 | kfree_skb(skb); | |
707 | return 0; | |
708 | ||
709 | discard_it: | |
710 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS); | |
711 | kfree_skb(skb); | |
712 | return 0; | |
713 | } | |
714 | ||
715 | int __init icmpv6_init(struct net_proto_family *ops) | |
716 | { | |
717 | struct sock *sk; | |
718 | int err, i, j; | |
719 | ||
6f912042 | 720 | for_each_possible_cpu(i) { |
1da177e4 LT |
721 | err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, |
722 | &per_cpu(__icmpv6_socket, i)); | |
723 | if (err < 0) { | |
724 | printk(KERN_ERR | |
725 | "Failed to initialize the ICMP6 control socket " | |
726 | "(err %d).\n", | |
727 | err); | |
728 | goto fail; | |
729 | } | |
730 | ||
731 | sk = per_cpu(__icmpv6_socket, i)->sk; | |
732 | sk->sk_allocation = GFP_ATOMIC; | |
733 | ||
734 | /* Enough space for 2 64K ICMP packets, including | |
735 | * sk_buff struct overhead. | |
736 | */ | |
737 | sk->sk_sndbuf = | |
738 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
739 | ||
740 | sk->sk_prot->unhash(sk); | |
741 | } | |
742 | ||
743 | ||
744 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) { | |
745 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
746 | err = -EAGAIN; | |
747 | goto fail; | |
748 | } | |
749 | ||
750 | return 0; | |
751 | ||
752 | fail: | |
753 | for (j = 0; j < i; j++) { | |
754 | if (!cpu_possible(j)) | |
755 | continue; | |
756 | sock_release(per_cpu(__icmpv6_socket, j)); | |
757 | } | |
758 | ||
759 | return err; | |
760 | } | |
761 | ||
762 | void icmpv6_cleanup(void) | |
763 | { | |
764 | int i; | |
765 | ||
6f912042 | 766 | for_each_possible_cpu(i) { |
1da177e4 LT |
767 | sock_release(per_cpu(__icmpv6_socket, i)); |
768 | } | |
769 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); | |
770 | } | |
771 | ||
9b5b5cff | 772 | static const struct icmp6_err { |
1da177e4 LT |
773 | int err; |
774 | int fatal; | |
775 | } tab_unreach[] = { | |
776 | { /* NOROUTE */ | |
777 | .err = ENETUNREACH, | |
778 | .fatal = 0, | |
779 | }, | |
780 | { /* ADM_PROHIBITED */ | |
781 | .err = EACCES, | |
782 | .fatal = 1, | |
783 | }, | |
784 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
785 | .err = EHOSTUNREACH, | |
786 | .fatal = 0, | |
787 | }, | |
788 | { /* ADDR_UNREACH */ | |
789 | .err = EHOSTUNREACH, | |
790 | .fatal = 0, | |
791 | }, | |
792 | { /* PORT_UNREACH */ | |
793 | .err = ECONNREFUSED, | |
794 | .fatal = 1, | |
795 | }, | |
796 | }; | |
797 | ||
798 | int icmpv6_err_convert(int type, int code, int *err) | |
799 | { | |
800 | int fatal = 0; | |
801 | ||
802 | *err = EPROTO; | |
803 | ||
804 | switch (type) { | |
805 | case ICMPV6_DEST_UNREACH: | |
806 | fatal = 1; | |
807 | if (code <= ICMPV6_PORT_UNREACH) { | |
808 | *err = tab_unreach[code].err; | |
809 | fatal = tab_unreach[code].fatal; | |
810 | } | |
811 | break; | |
812 | ||
813 | case ICMPV6_PKT_TOOBIG: | |
814 | *err = EMSGSIZE; | |
815 | break; | |
816 | ||
817 | case ICMPV6_PARAMPROB: | |
818 | *err = EPROTO; | |
819 | fatal = 1; | |
820 | break; | |
821 | ||
822 | case ICMPV6_TIME_EXCEED: | |
823 | *err = EHOSTUNREACH; | |
824 | break; | |
825 | }; | |
826 | ||
827 | return fatal; | |
828 | } | |
829 | ||
830 | #ifdef CONFIG_SYSCTL | |
831 | ctl_table ipv6_icmp_table[] = { | |
832 | { | |
833 | .ctl_name = NET_IPV6_ICMP_RATELIMIT, | |
834 | .procname = "ratelimit", | |
835 | .data = &sysctl_icmpv6_time, | |
836 | .maxlen = sizeof(int), | |
837 | .mode = 0644, | |
838 | .proc_handler = &proc_dointvec | |
839 | }, | |
840 | { .ctl_name = 0 }, | |
841 | }; | |
842 | #endif | |
843 |