Commit | Line | Data |
---|---|---|
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> | |
1da177e4 LT |
40 | #include <linux/sockios.h> |
41 | #include <linux/net.h> | |
42 | #include <linux/skbuff.h> | |
43 | #include <linux/init.h> | |
763ecff1 | 44 | #include <linux/netfilter.h> |
1da177e4 LT |
45 | |
46 | #ifdef CONFIG_SYSCTL | |
47 | #include <linux/sysctl.h> | |
48 | #endif | |
49 | ||
50 | #include <linux/inet.h> | |
51 | #include <linux/netdevice.h> | |
52 | #include <linux/icmpv6.h> | |
53 | ||
54 | #include <net/ip.h> | |
55 | #include <net/sock.h> | |
56 | ||
57 | #include <net/ipv6.h> | |
58 | #include <net/ip6_checksum.h> | |
59 | #include <net/protocol.h> | |
60 | #include <net/raw.h> | |
61 | #include <net/rawv6.h> | |
62 | #include <net/transp_v6.h> | |
63 | #include <net/ip6_route.h> | |
64 | #include <net/addrconf.h> | |
65 | #include <net/icmp.h> | |
8b7817f3 | 66 | #include <net/xfrm.h> |
1da177e4 LT |
67 | |
68 | #include <asm/uaccess.h> | |
69 | #include <asm/system.h> | |
70 | ||
ba89966c | 71 | DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly; |
7159039a | 72 | EXPORT_SYMBOL(icmpv6_statistics); |
14878f75 DS |
73 | DEFINE_SNMP_STAT(struct icmpv6msg_mib, icmpv6msg_statistics) __read_mostly; |
74 | EXPORT_SYMBOL(icmpv6msg_statistics); | |
1da177e4 LT |
75 | |
76 | /* | |
77 | * The ICMP socket(s). This is the most convenient way to flow control | |
78 | * our ICMP output as well as maintain a clean interface throughout | |
79 | * all layers. All Socketless IP sends will soon be gone. | |
80 | * | |
81 | * On SMP we have one ICMP socket per-cpu. | |
82 | */ | |
83 | static DEFINE_PER_CPU(struct socket *, __icmpv6_socket) = NULL; | |
84 | #define icmpv6_socket __get_cpu_var(__icmpv6_socket) | |
85 | ||
e5bbef20 | 86 | static int icmpv6_rcv(struct sk_buff *skb); |
1da177e4 LT |
87 | |
88 | static struct inet6_protocol icmpv6_protocol = { | |
89 | .handler = icmpv6_rcv, | |
8b7817f3 | 90 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
1da177e4 LT |
91 | }; |
92 | ||
93 | static __inline__ int icmpv6_xmit_lock(void) | |
94 | { | |
95 | local_bh_disable(); | |
96 | ||
97 | if (unlikely(!spin_trylock(&icmpv6_socket->sk->sk_lock.slock))) { | |
98 | /* This can happen if the output path (f.e. SIT or | |
99 | * ip6ip6 tunnel) signals dst_link_failure() for an | |
100 | * outgoing ICMP6 packet. | |
101 | */ | |
102 | local_bh_enable(); | |
103 | return 1; | |
104 | } | |
105 | return 0; | |
106 | } | |
107 | ||
108 | static __inline__ void icmpv6_xmit_unlock(void) | |
109 | { | |
110 | spin_unlock_bh(&icmpv6_socket->sk->sk_lock.slock); | |
111 | } | |
112 | ||
1ab1457c | 113 | /* |
1da177e4 LT |
114 | * Slightly more convenient version of icmpv6_send. |
115 | */ | |
116 | void icmpv6_param_prob(struct sk_buff *skb, int code, int pos) | |
117 | { | |
118 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev); | |
119 | kfree_skb(skb); | |
120 | } | |
121 | ||
122 | /* | |
123 | * Figure out, may we reply to this packet with icmp error. | |
124 | * | |
125 | * We do not reply, if: | |
126 | * - it was icmp error message. | |
127 | * - it is truncated, so that it is known, that protocol is ICMPV6 | |
128 | * (i.e. in the middle of some exthdr) | |
129 | * | |
130 | * --ANK (980726) | |
131 | */ | |
132 | ||
133 | static int is_ineligible(struct sk_buff *skb) | |
134 | { | |
0660e03f | 135 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
1da177e4 | 136 | int len = skb->len - ptr; |
0660e03f | 137 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
1da177e4 LT |
138 | |
139 | if (len < 0) | |
140 | return 1; | |
141 | ||
0d3d077c | 142 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); |
1da177e4 LT |
143 | if (ptr < 0) |
144 | return 0; | |
145 | if (nexthdr == IPPROTO_ICMPV6) { | |
146 | u8 _type, *tp; | |
147 | tp = skb_header_pointer(skb, | |
148 | ptr+offsetof(struct icmp6hdr, icmp6_type), | |
149 | sizeof(_type), &_type); | |
150 | if (tp == NULL || | |
151 | !(*tp & ICMPV6_INFOMSG_MASK)) | |
152 | return 1; | |
153 | } | |
154 | return 0; | |
155 | } | |
156 | ||
1ab1457c YH |
157 | /* |
158 | * Check the ICMP output rate limit | |
1da177e4 LT |
159 | */ |
160 | static inline int icmpv6_xrlim_allow(struct sock *sk, int type, | |
161 | struct flowi *fl) | |
162 | { | |
163 | struct dst_entry *dst; | |
164 | int res = 0; | |
165 | ||
166 | /* Informational messages are not limited. */ | |
167 | if (type & ICMPV6_INFOMSG_MASK) | |
168 | return 1; | |
169 | ||
170 | /* Do not limit pmtu discovery, it would break it. */ | |
171 | if (type == ICMPV6_PKT_TOOBIG) | |
172 | return 1; | |
173 | ||
1ab1457c | 174 | /* |
1da177e4 LT |
175 | * Look up the output route. |
176 | * XXX: perhaps the expire for routing entries cloned by | |
177 | * this lookup should be more aggressive (not longer than timeout). | |
178 | */ | |
179 | dst = ip6_route_output(sk, fl); | |
180 | if (dst->error) { | |
a11d206d YH |
181 | IP6_INC_STATS(ip6_dst_idev(dst), |
182 | IPSTATS_MIB_OUTNOROUTES); | |
1da177e4 LT |
183 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
184 | res = 1; | |
185 | } else { | |
186 | struct rt6_info *rt = (struct rt6_info *)dst; | |
41a76906 | 187 | int tmo = init_net.ipv6.sysctl.icmpv6_time; |
1da177e4 LT |
188 | |
189 | /* Give more bandwidth to wider prefixes. */ | |
190 | if (rt->rt6i_dst.plen < 128) | |
191 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); | |
192 | ||
193 | res = xrlim_allow(dst, tmo); | |
194 | } | |
195 | dst_release(dst); | |
196 | return res; | |
197 | } | |
198 | ||
199 | /* | |
200 | * an inline helper for the "simple" if statement below | |
201 | * checks if parameter problem report is caused by an | |
1ab1457c | 202 | * unrecognized IPv6 option that has the Option Type |
1da177e4 LT |
203 | * highest-order two bits set to 10 |
204 | */ | |
205 | ||
206 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) | |
207 | { | |
208 | u8 _optval, *op; | |
209 | ||
bbe735e4 | 210 | offset += skb_network_offset(skb); |
1da177e4 LT |
211 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
212 | if (op == NULL) | |
213 | return 1; | |
214 | return (*op & 0xC0) == 0x80; | |
215 | } | |
216 | ||
217 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) | |
218 | { | |
219 | struct sk_buff *skb; | |
220 | struct icmp6hdr *icmp6h; | |
221 | int err = 0; | |
222 | ||
223 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
224 | goto out; | |
225 | ||
cc70ab26 | 226 | icmp6h = icmp6_hdr(skb); |
1da177e4 LT |
227 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
228 | icmp6h->icmp6_cksum = 0; | |
229 | ||
230 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
231 | skb->csum = csum_partial((char *)icmp6h, | |
232 | sizeof(struct icmp6hdr), skb->csum); | |
233 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, | |
234 | &fl->fl6_dst, | |
235 | len, fl->proto, | |
236 | skb->csum); | |
237 | } else { | |
868c86bc | 238 | __wsum tmp_csum = 0; |
1da177e4 LT |
239 | |
240 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
241 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
242 | } | |
243 | ||
244 | tmp_csum = csum_partial((char *)icmp6h, | |
245 | sizeof(struct icmp6hdr), tmp_csum); | |
868c86bc AV |
246 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, |
247 | &fl->fl6_dst, | |
248 | len, fl->proto, | |
249 | tmp_csum); | |
1da177e4 | 250 | } |
1da177e4 LT |
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; | |
5f92a738 | 266 | __wsum csum = 0; |
1da177e4 LT |
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 | ||
59fbb3a6 | 276 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
79383236 MN |
277 | static void mip6_addr_swap(struct sk_buff *skb) |
278 | { | |
0660e03f | 279 | struct ipv6hdr *iph = ipv6_hdr(skb); |
79383236 MN |
280 | struct inet6_skb_parm *opt = IP6CB(skb); |
281 | struct ipv6_destopt_hao *hao; | |
282 | struct in6_addr tmp; | |
283 | int off; | |
284 | ||
285 | if (opt->dsthao) { | |
286 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
287 | if (likely(off >= 0)) { | |
d56f90a7 ACM |
288 | hao = (struct ipv6_destopt_hao *) |
289 | (skb_network_header(skb) + off); | |
79383236 MN |
290 | ipv6_addr_copy(&tmp, &iph->saddr); |
291 | ipv6_addr_copy(&iph->saddr, &hao->addr); | |
292 | ipv6_addr_copy(&hao->addr, &tmp); | |
293 | } | |
294 | } | |
295 | } | |
296 | #else | |
297 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
298 | #endif | |
299 | ||
1da177e4 LT |
300 | /* |
301 | * Send an ICMP message in response to a packet in error | |
302 | */ | |
1ab1457c | 303 | void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info, |
1da177e4 LT |
304 | struct net_device *dev) |
305 | { | |
306 | struct inet6_dev *idev = NULL; | |
0660e03f | 307 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
84427d53 YH |
308 | struct sock *sk; |
309 | struct ipv6_pinfo *np; | |
1da177e4 LT |
310 | struct in6_addr *saddr = NULL; |
311 | struct dst_entry *dst; | |
8b7817f3 | 312 | struct dst_entry *dst2; |
1da177e4 LT |
313 | struct icmp6hdr tmp_hdr; |
314 | struct flowi fl; | |
8b7817f3 | 315 | struct flowi fl2; |
1da177e4 LT |
316 | struct icmpv6_msg msg; |
317 | int iif = 0; | |
318 | int addr_type = 0; | |
319 | int len; | |
41a1f8ea | 320 | int hlimit, tclass; |
1da177e4 LT |
321 | int err = 0; |
322 | ||
27a884dc ACM |
323 | if ((u8 *)hdr < skb->head || |
324 | (skb->network_header + sizeof(*hdr)) > skb->tail) | |
1da177e4 LT |
325 | return; |
326 | ||
327 | /* | |
1ab1457c | 328 | * Make sure we respect the rules |
1da177e4 LT |
329 | * i.e. RFC 1885 2.4(e) |
330 | * Rule (e.1) is enforced by not using icmpv6_send | |
331 | * in any code that processes icmp errors. | |
332 | */ | |
333 | addr_type = ipv6_addr_type(&hdr->daddr); | |
334 | ||
bfeade08 | 335 | if (ipv6_chk_addr(&init_net, &hdr->daddr, skb->dev, 0)) |
1da177e4 LT |
336 | saddr = &hdr->daddr; |
337 | ||
338 | /* | |
339 | * Dest addr check | |
340 | */ | |
341 | ||
342 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
343 | if (type != ICMPV6_PKT_TOOBIG && | |
1ab1457c YH |
344 | !(type == ICMPV6_PARAMPROB && |
345 | code == ICMPV6_UNK_OPTION && | |
1da177e4 LT |
346 | (opt_unrec(skb, info)))) |
347 | return; | |
348 | ||
349 | saddr = NULL; | |
350 | } | |
351 | ||
352 | addr_type = ipv6_addr_type(&hdr->saddr); | |
353 | ||
354 | /* | |
355 | * Source addr check | |
356 | */ | |
357 | ||
358 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
359 | iif = skb->dev->ifindex; | |
360 | ||
361 | /* | |
8de3351e YH |
362 | * Must not send error if the source does not uniquely |
363 | * identify a single node (RFC2463 Section 2.4). | |
364 | * We check unspecified / multicast addresses here, | |
365 | * and anycast addresses will be checked later. | |
1da177e4 LT |
366 | */ |
367 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 368 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
369 | return; |
370 | } | |
371 | ||
1ab1457c | 372 | /* |
1da177e4 LT |
373 | * Never answer to a ICMP packet. |
374 | */ | |
375 | if (is_ineligible(skb)) { | |
64ce2073 | 376 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
377 | return; |
378 | } | |
379 | ||
79383236 MN |
380 | mip6_addr_swap(skb); |
381 | ||
1da177e4 LT |
382 | memset(&fl, 0, sizeof(fl)); |
383 | fl.proto = IPPROTO_ICMPV6; | |
384 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); | |
385 | if (saddr) | |
386 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
387 | fl.oif = iif; | |
388 | fl.fl_icmp_type = type; | |
389 | fl.fl_icmp_code = code; | |
beb8d13b | 390 | security_skb_classify_flow(skb, &fl); |
1da177e4 LT |
391 | |
392 | if (icmpv6_xmit_lock()) | |
393 | return; | |
394 | ||
84427d53 YH |
395 | sk = icmpv6_socket->sk; |
396 | np = inet6_sk(sk); | |
397 | ||
1da177e4 LT |
398 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
399 | goto out; | |
400 | ||
401 | tmp_hdr.icmp6_type = type; | |
402 | tmp_hdr.icmp6_code = code; | |
403 | tmp_hdr.icmp6_cksum = 0; | |
404 | tmp_hdr.icmp6_pointer = htonl(info); | |
405 | ||
406 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) | |
407 | fl.oif = np->mcast_oif; | |
408 | ||
409 | err = ip6_dst_lookup(sk, &dst, &fl); | |
410 | if (err) | |
411 | goto out; | |
8de3351e YH |
412 | |
413 | /* | |
414 | * We won't send icmp if the destination is known | |
415 | * anycast. | |
416 | */ | |
417 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
418 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
419 | goto out_dst_release; | |
420 | } | |
421 | ||
8b7817f3 HX |
422 | /* No need to clone since we're just using its address. */ |
423 | dst2 = dst; | |
424 | ||
425 | err = xfrm_lookup(&dst, &fl, sk, 0); | |
426 | switch (err) { | |
427 | case 0: | |
428 | if (dst != dst2) | |
429 | goto route_done; | |
430 | break; | |
431 | case -EPERM: | |
432 | dst = NULL; | |
433 | break; | |
434 | default: | |
435 | goto out; | |
436 | } | |
437 | ||
438 | if (xfrm_decode_session_reverse(skb, &fl2, AF_INET6)) | |
439 | goto out; | |
440 | ||
441 | if (ip6_dst_lookup(sk, &dst2, &fl)) | |
e104411b | 442 | goto out; |
1da177e4 | 443 | |
8b7817f3 HX |
444 | err = xfrm_lookup(&dst2, &fl, sk, XFRM_LOOKUP_ICMP); |
445 | if (err == -ENOENT) { | |
446 | if (!dst) | |
447 | goto out; | |
448 | goto route_done; | |
449 | } | |
450 | ||
451 | dst_release(dst); | |
452 | dst = dst2; | |
453 | ||
454 | if (err) | |
455 | goto out; | |
456 | ||
457 | route_done: | |
1da177e4 LT |
458 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
459 | hlimit = np->mcast_hops; | |
460 | else | |
461 | hlimit = np->hop_limit; | |
462 | if (hlimit < 0) | |
463 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
464 | if (hlimit < 0) | |
465 | hlimit = ipv6_get_hoplimit(dst->dev); | |
466 | ||
e012d51c | 467 | tclass = np->tclass; |
41a1f8ea YH |
468 | if (tclass < 0) |
469 | tclass = 0; | |
470 | ||
1da177e4 | 471 | msg.skb = skb; |
bbe735e4 | 472 | msg.offset = skb_network_offset(skb); |
763ecff1 | 473 | msg.type = type; |
1da177e4 LT |
474 | |
475 | len = skb->len - msg.offset; | |
476 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
477 | if (len < 0) { | |
64ce2073 | 478 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
479 | goto out_dst_release; |
480 | } | |
481 | ||
482 | idev = in6_dev_get(skb->dev); | |
483 | ||
484 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
485 | len + sizeof(struct icmp6hdr), | |
486 | sizeof(struct icmp6hdr), | |
41a1f8ea | 487 | hlimit, tclass, NULL, &fl, (struct rt6_info*)dst, |
1da177e4 LT |
488 | MSG_DONTWAIT); |
489 | if (err) { | |
490 | ip6_flush_pending_frames(sk); | |
491 | goto out_put; | |
492 | } | |
493 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
494 | ||
1da177e4 LT |
495 | out_put: |
496 | if (likely(idev != NULL)) | |
497 | in6_dev_put(idev); | |
498 | out_dst_release: | |
499 | dst_release(dst); | |
500 | out: | |
501 | icmpv6_xmit_unlock(); | |
502 | } | |
503 | ||
7159039a YH |
504 | EXPORT_SYMBOL(icmpv6_send); |
505 | ||
1da177e4 LT |
506 | static void icmpv6_echo_reply(struct sk_buff *skb) |
507 | { | |
84427d53 | 508 | struct sock *sk; |
1da177e4 | 509 | struct inet6_dev *idev; |
84427d53 | 510 | struct ipv6_pinfo *np; |
1da177e4 | 511 | struct in6_addr *saddr = NULL; |
cc70ab26 | 512 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 LT |
513 | struct icmp6hdr tmp_hdr; |
514 | struct flowi fl; | |
515 | struct icmpv6_msg msg; | |
516 | struct dst_entry *dst; | |
517 | int err = 0; | |
518 | int hlimit; | |
41a1f8ea | 519 | int tclass; |
1da177e4 | 520 | |
0660e03f | 521 | saddr = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
522 | |
523 | if (!ipv6_unicast_destination(skb)) | |
524 | saddr = NULL; | |
525 | ||
526 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
527 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
528 | ||
529 | memset(&fl, 0, sizeof(fl)); | |
530 | fl.proto = IPPROTO_ICMPV6; | |
0660e03f | 531 | ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr); |
1da177e4 LT |
532 | if (saddr) |
533 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
534 | fl.oif = skb->dev->ifindex; | |
535 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; | |
beb8d13b | 536 | security_skb_classify_flow(skb, &fl); |
1da177e4 LT |
537 | |
538 | if (icmpv6_xmit_lock()) | |
539 | return; | |
540 | ||
84427d53 YH |
541 | sk = icmpv6_socket->sk; |
542 | np = inet6_sk(sk); | |
543 | ||
1da177e4 LT |
544 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
545 | fl.oif = np->mcast_oif; | |
546 | ||
547 | err = ip6_dst_lookup(sk, &dst, &fl); | |
548 | if (err) | |
549 | goto out; | |
550 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) | |
e104411b | 551 | goto out; |
1da177e4 LT |
552 | |
553 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
554 | hlimit = np->mcast_hops; | |
555 | else | |
556 | hlimit = np->hop_limit; | |
557 | if (hlimit < 0) | |
558 | hlimit = dst_metric(dst, RTAX_HOPLIMIT); | |
559 | if (hlimit < 0) | |
560 | hlimit = ipv6_get_hoplimit(dst->dev); | |
561 | ||
e012d51c | 562 | tclass = np->tclass; |
41a1f8ea YH |
563 | if (tclass < 0) |
564 | tclass = 0; | |
565 | ||
1da177e4 LT |
566 | idev = in6_dev_get(skb->dev); |
567 | ||
568 | msg.skb = skb; | |
569 | msg.offset = 0; | |
763ecff1 | 570 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
571 | |
572 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
41a1f8ea | 573 | sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl, |
1da177e4 LT |
574 | (struct rt6_info*)dst, MSG_DONTWAIT); |
575 | ||
576 | if (err) { | |
577 | ip6_flush_pending_frames(sk); | |
578 | goto out_put; | |
579 | } | |
580 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
581 | ||
1ab1457c | 582 | out_put: |
1da177e4 LT |
583 | if (likely(idev != NULL)) |
584 | in6_dev_put(idev); | |
1da177e4 | 585 | dst_release(dst); |
1ab1457c | 586 | out: |
1da177e4 LT |
587 | icmpv6_xmit_unlock(); |
588 | } | |
589 | ||
04ce6909 | 590 | static void icmpv6_notify(struct sk_buff *skb, int type, int code, __be32 info) |
1da177e4 | 591 | { |
1da177e4 | 592 | struct inet6_protocol *ipprot; |
1da177e4 LT |
593 | int inner_offset; |
594 | int hash; | |
595 | u8 nexthdr; | |
596 | ||
597 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
598 | return; | |
599 | ||
600 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
601 | if (ipv6_ext_hdr(nexthdr)) { | |
602 | /* now skip over extension headers */ | |
0d3d077c | 603 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
604 | if (inner_offset<0) |
605 | return; | |
606 | } else { | |
607 | inner_offset = sizeof(struct ipv6hdr); | |
608 | } | |
609 | ||
610 | /* Checkin header including 8 bytes of inner protocol header. */ | |
611 | if (!pskb_may_pull(skb, inner_offset+8)) | |
612 | return; | |
613 | ||
1da177e4 LT |
614 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
615 | Without this we will not able f.e. to make source routed | |
616 | pmtu discovery. | |
617 | Corresponding argument (opt) to notifiers is already added. | |
618 | --ANK (980726) | |
619 | */ | |
620 | ||
621 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
622 | ||
623 | rcu_read_lock(); | |
624 | ipprot = rcu_dereference(inet6_protos[hash]); | |
625 | if (ipprot && ipprot->err_handler) | |
626 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
627 | rcu_read_unlock(); | |
628 | ||
69d6da0b | 629 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 630 | } |
1ab1457c | 631 | |
1da177e4 LT |
632 | /* |
633 | * Handle icmp messages | |
634 | */ | |
635 | ||
e5bbef20 | 636 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 637 | { |
1da177e4 LT |
638 | struct net_device *dev = skb->dev; |
639 | struct inet6_dev *idev = __in6_dev_get(dev); | |
640 | struct in6_addr *saddr, *daddr; | |
641 | struct ipv6hdr *orig_hdr; | |
642 | struct icmp6hdr *hdr; | |
643 | int type; | |
644 | ||
aebcf82c | 645 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
8b7817f3 HX |
646 | int nh; |
647 | ||
aebcf82c HX |
648 | if (!(skb->sp && skb->sp->xvec[skb->sp->len - 1]->props.flags & |
649 | XFRM_STATE_ICMP)) | |
650 | goto drop_no_count; | |
651 | ||
8b7817f3 HX |
652 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
653 | goto drop_no_count; | |
654 | ||
655 | nh = skb_network_offset(skb); | |
656 | skb_set_network_header(skb, sizeof(*hdr)); | |
657 | ||
658 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
659 | goto drop_no_count; | |
660 | ||
661 | skb_set_network_header(skb, nh); | |
662 | } | |
663 | ||
1da177e4 LT |
664 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS); |
665 | ||
0660e03f ACM |
666 | saddr = &ipv6_hdr(skb)->saddr; |
667 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
668 | |
669 | /* Perform checksum. */ | |
fb286bb2 | 670 | switch (skb->ip_summed) { |
84fa7933 | 671 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
672 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
673 | skb->csum)) | |
674 | break; | |
675 | /* fall through */ | |
676 | case CHECKSUM_NONE: | |
868c86bc AV |
677 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
678 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 679 | if (__skb_checksum_complete(skb)) { |
46b86a2d | 680 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [" NIP6_FMT " > " NIP6_FMT "]\n", |
64ce2073 | 681 | NIP6(*saddr), NIP6(*daddr)); |
1da177e4 LT |
682 | goto discard_it; |
683 | } | |
684 | } | |
685 | ||
8cf22943 HX |
686 | if (!pskb_pull(skb, sizeof(*hdr))) |
687 | goto discard_it; | |
1da177e4 | 688 | |
cc70ab26 | 689 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
690 | |
691 | type = hdr->icmp6_type; | |
692 | ||
14878f75 | 693 | ICMP6MSGIN_INC_STATS_BH(idev, type); |
1da177e4 LT |
694 | |
695 | switch (type) { | |
696 | case ICMPV6_ECHO_REQUEST: | |
697 | icmpv6_echo_reply(skb); | |
698 | break; | |
699 | ||
700 | case ICMPV6_ECHO_REPLY: | |
701 | /* we couldn't care less */ | |
702 | break; | |
703 | ||
704 | case ICMPV6_PKT_TOOBIG: | |
705 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
706 | standard destination cache. Seems, only "advanced" | |
707 | destination cache will allow to solve this problem | |
708 | --ANK (980726) | |
709 | */ | |
710 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
711 | goto discard_it; | |
cc70ab26 | 712 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
713 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
714 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
715 | ntohl(hdr->icmp6_mtu)); | |
716 | ||
717 | /* | |
718 | * Drop through to notify | |
719 | */ | |
720 | ||
721 | case ICMPV6_DEST_UNREACH: | |
722 | case ICMPV6_TIME_EXCEED: | |
723 | case ICMPV6_PARAMPROB: | |
724 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
725 | break; | |
726 | ||
727 | case NDISC_ROUTER_SOLICITATION: | |
728 | case NDISC_ROUTER_ADVERTISEMENT: | |
729 | case NDISC_NEIGHBOUR_SOLICITATION: | |
730 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
731 | case NDISC_REDIRECT: | |
732 | ndisc_rcv(skb); | |
733 | break; | |
734 | ||
735 | case ICMPV6_MGM_QUERY: | |
736 | igmp6_event_query(skb); | |
737 | break; | |
738 | ||
739 | case ICMPV6_MGM_REPORT: | |
740 | igmp6_event_report(skb); | |
741 | break; | |
742 | ||
743 | case ICMPV6_MGM_REDUCTION: | |
744 | case ICMPV6_NI_QUERY: | |
745 | case ICMPV6_NI_REPLY: | |
746 | case ICMPV6_MLD2_REPORT: | |
747 | case ICMPV6_DHAAD_REQUEST: | |
748 | case ICMPV6_DHAAD_REPLY: | |
749 | case ICMPV6_MOBILE_PREFIX_SOL: | |
750 | case ICMPV6_MOBILE_PREFIX_ADV: | |
751 | break; | |
752 | ||
753 | default: | |
64ce2073 | 754 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
755 | |
756 | /* informational */ | |
757 | if (type & ICMPV6_INFOMSG_MASK) | |
758 | break; | |
759 | ||
1ab1457c YH |
760 | /* |
761 | * error of unknown type. | |
762 | * must pass to upper level | |
1da177e4 LT |
763 | */ |
764 | ||
765 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
766 | } |
767 | ||
1da177e4 LT |
768 | kfree_skb(skb); |
769 | return 0; | |
770 | ||
771 | discard_it: | |
772 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS); | |
8b7817f3 | 773 | drop_no_count: |
1da177e4 LT |
774 | kfree_skb(skb); |
775 | return 0; | |
776 | } | |
777 | ||
640c41c7 IM |
778 | /* |
779 | * Special lock-class for __icmpv6_socket: | |
780 | */ | |
781 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
782 | ||
1da177e4 LT |
783 | int __init icmpv6_init(struct net_proto_family *ops) |
784 | { | |
785 | struct sock *sk; | |
786 | int err, i, j; | |
787 | ||
6f912042 | 788 | for_each_possible_cpu(i) { |
1da177e4 LT |
789 | err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, |
790 | &per_cpu(__icmpv6_socket, i)); | |
791 | if (err < 0) { | |
792 | printk(KERN_ERR | |
793 | "Failed to initialize the ICMP6 control socket " | |
794 | "(err %d).\n", | |
795 | err); | |
796 | goto fail; | |
797 | } | |
798 | ||
799 | sk = per_cpu(__icmpv6_socket, i)->sk; | |
800 | sk->sk_allocation = GFP_ATOMIC; | |
640c41c7 IM |
801 | /* |
802 | * Split off their lock-class, because sk->sk_dst_lock | |
803 | * gets used from softirqs, which is safe for | |
804 | * __icmpv6_socket (because those never get directly used | |
805 | * via userspace syscalls), but unsafe for normal sockets. | |
806 | */ | |
807 | lockdep_set_class(&sk->sk_dst_lock, | |
808 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
809 | |
810 | /* Enough space for 2 64K ICMP packets, including | |
811 | * sk_buff struct overhead. | |
812 | */ | |
813 | sk->sk_sndbuf = | |
814 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
815 | ||
816 | sk->sk_prot->unhash(sk); | |
817 | } | |
818 | ||
819 | ||
820 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) { | |
821 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
822 | err = -EAGAIN; | |
823 | goto fail; | |
824 | } | |
825 | ||
826 | return 0; | |
827 | ||
828 | fail: | |
829 | for (j = 0; j < i; j++) { | |
830 | if (!cpu_possible(j)) | |
831 | continue; | |
832 | sock_release(per_cpu(__icmpv6_socket, j)); | |
833 | } | |
834 | ||
835 | return err; | |
836 | } | |
837 | ||
838 | void icmpv6_cleanup(void) | |
839 | { | |
840 | int i; | |
841 | ||
6f912042 | 842 | for_each_possible_cpu(i) { |
1da177e4 LT |
843 | sock_release(per_cpu(__icmpv6_socket, i)); |
844 | } | |
845 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); | |
846 | } | |
847 | ||
9b5b5cff | 848 | static const struct icmp6_err { |
1da177e4 LT |
849 | int err; |
850 | int fatal; | |
851 | } tab_unreach[] = { | |
852 | { /* NOROUTE */ | |
853 | .err = ENETUNREACH, | |
854 | .fatal = 0, | |
855 | }, | |
856 | { /* ADM_PROHIBITED */ | |
857 | .err = EACCES, | |
858 | .fatal = 1, | |
859 | }, | |
860 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
861 | .err = EHOSTUNREACH, | |
862 | .fatal = 0, | |
863 | }, | |
864 | { /* ADDR_UNREACH */ | |
865 | .err = EHOSTUNREACH, | |
866 | .fatal = 0, | |
867 | }, | |
868 | { /* PORT_UNREACH */ | |
869 | .err = ECONNREFUSED, | |
870 | .fatal = 1, | |
871 | }, | |
872 | }; | |
873 | ||
874 | int icmpv6_err_convert(int type, int code, int *err) | |
875 | { | |
876 | int fatal = 0; | |
877 | ||
878 | *err = EPROTO; | |
879 | ||
880 | switch (type) { | |
881 | case ICMPV6_DEST_UNREACH: | |
882 | fatal = 1; | |
883 | if (code <= ICMPV6_PORT_UNREACH) { | |
884 | *err = tab_unreach[code].err; | |
885 | fatal = tab_unreach[code].fatal; | |
886 | } | |
887 | break; | |
888 | ||
889 | case ICMPV6_PKT_TOOBIG: | |
890 | *err = EMSGSIZE; | |
891 | break; | |
1ab1457c | 892 | |
1da177e4 LT |
893 | case ICMPV6_PARAMPROB: |
894 | *err = EPROTO; | |
895 | fatal = 1; | |
896 | break; | |
897 | ||
898 | case ICMPV6_TIME_EXCEED: | |
899 | *err = EHOSTUNREACH; | |
900 | break; | |
3ff50b79 | 901 | } |
1da177e4 LT |
902 | |
903 | return fatal; | |
904 | } | |
905 | ||
7159039a YH |
906 | EXPORT_SYMBOL(icmpv6_err_convert); |
907 | ||
1da177e4 | 908 | #ifdef CONFIG_SYSCTL |
760f2d01 | 909 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 LT |
910 | { |
911 | .ctl_name = NET_IPV6_ICMP_RATELIMIT, | |
912 | .procname = "ratelimit", | |
41a76906 | 913 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
914 | .maxlen = sizeof(int), |
915 | .mode = 0644, | |
916 | .proc_handler = &proc_dointvec | |
917 | }, | |
918 | { .ctl_name = 0 }, | |
919 | }; | |
760f2d01 DL |
920 | |
921 | struct ctl_table *ipv6_icmp_sysctl_init(struct net *net) | |
922 | { | |
923 | struct ctl_table *table; | |
924 | ||
925 | table = kmemdup(ipv6_icmp_table_template, | |
926 | sizeof(ipv6_icmp_table_template), | |
927 | GFP_KERNEL); | |
928 | return table; | |
929 | } | |
1da177e4 LT |
930 | #endif |
931 |