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 | * | |
1da177e4 LT |
8 | * Based on net/ipv4/icmp.c |
9 | * | |
10 | * RFC 1885 | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | */ | |
17 | ||
18 | /* | |
19 | * Changes: | |
20 | * | |
21 | * Andi Kleen : exception handling | |
22 | * Andi Kleen add rate limits. never reply to a icmp. | |
23 | * add more length checks and other fixes. | |
24 | * yoshfuji : ensure to sent parameter problem for | |
25 | * fragments. | |
26 | * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. | |
27 | * Randy Dunlap and | |
28 | * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support | |
29 | * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data | |
30 | */ | |
31 | ||
32 | #include <linux/module.h> | |
33 | #include <linux/errno.h> | |
34 | #include <linux/types.h> | |
35 | #include <linux/socket.h> | |
36 | #include <linux/in.h> | |
37 | #include <linux/kernel.h> | |
1da177e4 LT |
38 | #include <linux/sockios.h> |
39 | #include <linux/net.h> | |
40 | #include <linux/skbuff.h> | |
41 | #include <linux/init.h> | |
763ecff1 | 42 | #include <linux/netfilter.h> |
1da177e4 LT |
43 | |
44 | #ifdef CONFIG_SYSCTL | |
45 | #include <linux/sysctl.h> | |
46 | #endif | |
47 | ||
48 | #include <linux/inet.h> | |
49 | #include <linux/netdevice.h> | |
50 | #include <linux/icmpv6.h> | |
51 | ||
52 | #include <net/ip.h> | |
53 | #include <net/sock.h> | |
54 | ||
55 | #include <net/ipv6.h> | |
56 | #include <net/ip6_checksum.h> | |
57 | #include <net/protocol.h> | |
58 | #include <net/raw.h> | |
59 | #include <net/rawv6.h> | |
60 | #include <net/transp_v6.h> | |
61 | #include <net/ip6_route.h> | |
62 | #include <net/addrconf.h> | |
63 | #include <net/icmp.h> | |
8b7817f3 | 64 | #include <net/xfrm.h> |
1ed8516f | 65 | #include <net/inet_common.h> |
1da177e4 LT |
66 | |
67 | #include <asm/uaccess.h> | |
68 | #include <asm/system.h> | |
69 | ||
ba89966c | 70 | DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics) __read_mostly; |
7159039a | 71 | EXPORT_SYMBOL(icmpv6_statistics); |
14878f75 DS |
72 | DEFINE_SNMP_STAT(struct icmpv6msg_mib, icmpv6msg_statistics) __read_mostly; |
73 | EXPORT_SYMBOL(icmpv6msg_statistics); | |
1da177e4 LT |
74 | |
75 | /* | |
76 | * The ICMP socket(s). This is the most convenient way to flow control | |
77 | * our ICMP output as well as maintain a clean interface throughout | |
78 | * all layers. All Socketless IP sends will soon be gone. | |
79 | * | |
80 | * On SMP we have one ICMP socket per-cpu. | |
81 | */ | |
98c6d1b2 DL |
82 | static inline struct sock *icmpv6_sk(struct net *net) |
83 | { | |
84 | return net->ipv6.icmp_sk[smp_processor_id()]; | |
85 | } | |
1da177e4 | 86 | |
e5bbef20 | 87 | static int icmpv6_rcv(struct sk_buff *skb); |
1da177e4 LT |
88 | |
89 | static struct inet6_protocol icmpv6_protocol = { | |
90 | .handler = icmpv6_rcv, | |
8b7817f3 | 91 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
1da177e4 LT |
92 | }; |
93 | ||
405666db | 94 | static __inline__ int icmpv6_xmit_lock(struct sock *sk) |
1da177e4 LT |
95 | { |
96 | local_bh_disable(); | |
97 | ||
405666db | 98 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
99 | /* This can happen if the output path (f.e. SIT or |
100 | * ip6ip6 tunnel) signals dst_link_failure() for an | |
101 | * outgoing ICMP6 packet. | |
102 | */ | |
103 | local_bh_enable(); | |
104 | return 1; | |
105 | } | |
106 | return 0; | |
107 | } | |
108 | ||
405666db | 109 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
1da177e4 | 110 | { |
405666db | 111 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
112 | } |
113 | ||
1ab1457c | 114 | /* |
1da177e4 LT |
115 | * Slightly more convenient version of icmpv6_send. |
116 | */ | |
117 | void icmpv6_param_prob(struct sk_buff *skb, int code, int pos) | |
118 | { | |
119 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev); | |
120 | kfree_skb(skb); | |
121 | } | |
122 | ||
123 | /* | |
124 | * Figure out, may we reply to this packet with icmp error. | |
125 | * | |
126 | * We do not reply, if: | |
127 | * - it was icmp error message. | |
128 | * - it is truncated, so that it is known, that protocol is ICMPV6 | |
129 | * (i.e. in the middle of some exthdr) | |
130 | * | |
131 | * --ANK (980726) | |
132 | */ | |
133 | ||
134 | static int is_ineligible(struct sk_buff *skb) | |
135 | { | |
0660e03f | 136 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
1da177e4 | 137 | int len = skb->len - ptr; |
0660e03f | 138 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
1da177e4 LT |
139 | |
140 | if (len < 0) | |
141 | return 1; | |
142 | ||
0d3d077c | 143 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr); |
1da177e4 LT |
144 | if (ptr < 0) |
145 | return 0; | |
146 | if (nexthdr == IPPROTO_ICMPV6) { | |
147 | u8 _type, *tp; | |
148 | tp = skb_header_pointer(skb, | |
149 | ptr+offsetof(struct icmp6hdr, icmp6_type), | |
150 | sizeof(_type), &_type); | |
151 | if (tp == NULL || | |
152 | !(*tp & ICMPV6_INFOMSG_MASK)) | |
153 | return 1; | |
154 | } | |
155 | return 0; | |
156 | } | |
157 | ||
1ab1457c YH |
158 | /* |
159 | * Check the ICMP output rate limit | |
1da177e4 LT |
160 | */ |
161 | static inline int icmpv6_xrlim_allow(struct sock *sk, int type, | |
162 | struct flowi *fl) | |
163 | { | |
164 | struct dst_entry *dst; | |
3b1e0a65 | 165 | struct net *net = sock_net(sk); |
1da177e4 LT |
166 | int res = 0; |
167 | ||
168 | /* Informational messages are not limited. */ | |
169 | if (type & ICMPV6_INFOMSG_MASK) | |
170 | return 1; | |
171 | ||
172 | /* Do not limit pmtu discovery, it would break it. */ | |
173 | if (type == ICMPV6_PKT_TOOBIG) | |
174 | return 1; | |
175 | ||
1ab1457c | 176 | /* |
1da177e4 LT |
177 | * Look up the output route. |
178 | * XXX: perhaps the expire for routing entries cloned by | |
179 | * this lookup should be more aggressive (not longer than timeout). | |
180 | */ | |
9a43b709 | 181 | dst = ip6_route_output(net, sk, fl); |
1da177e4 | 182 | if (dst->error) { |
a11d206d YH |
183 | IP6_INC_STATS(ip6_dst_idev(dst), |
184 | IPSTATS_MIB_OUTNOROUTES); | |
1da177e4 LT |
185 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
186 | res = 1; | |
187 | } else { | |
188 | struct rt6_info *rt = (struct rt6_info *)dst; | |
9a43b709 | 189 | int tmo = net->ipv6.sysctl.icmpv6_time; |
1da177e4 LT |
190 | |
191 | /* Give more bandwidth to wider prefixes. */ | |
192 | if (rt->rt6i_dst.plen < 128) | |
193 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); | |
194 | ||
195 | res = xrlim_allow(dst, tmo); | |
196 | } | |
197 | dst_release(dst); | |
198 | return res; | |
199 | } | |
200 | ||
201 | /* | |
202 | * an inline helper for the "simple" if statement below | |
203 | * checks if parameter problem report is caused by an | |
1ab1457c | 204 | * unrecognized IPv6 option that has the Option Type |
1da177e4 LT |
205 | * highest-order two bits set to 10 |
206 | */ | |
207 | ||
208 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) | |
209 | { | |
210 | u8 _optval, *op; | |
211 | ||
bbe735e4 | 212 | offset += skb_network_offset(skb); |
1da177e4 LT |
213 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
214 | if (op == NULL) | |
215 | return 1; | |
216 | return (*op & 0xC0) == 0x80; | |
217 | } | |
218 | ||
219 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) | |
220 | { | |
221 | struct sk_buff *skb; | |
222 | struct icmp6hdr *icmp6h; | |
223 | int err = 0; | |
224 | ||
225 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
226 | goto out; | |
227 | ||
cc70ab26 | 228 | icmp6h = icmp6_hdr(skb); |
1da177e4 LT |
229 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
230 | icmp6h->icmp6_cksum = 0; | |
231 | ||
232 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
233 | skb->csum = csum_partial((char *)icmp6h, | |
234 | sizeof(struct icmp6hdr), skb->csum); | |
235 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, | |
236 | &fl->fl6_dst, | |
237 | len, fl->proto, | |
238 | skb->csum); | |
239 | } else { | |
868c86bc | 240 | __wsum tmp_csum = 0; |
1da177e4 LT |
241 | |
242 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
243 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
244 | } | |
245 | ||
246 | tmp_csum = csum_partial((char *)icmp6h, | |
247 | sizeof(struct icmp6hdr), tmp_csum); | |
868c86bc AV |
248 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, |
249 | &fl->fl6_dst, | |
250 | len, fl->proto, | |
251 | tmp_csum); | |
1da177e4 | 252 | } |
1da177e4 LT |
253 | ip6_push_pending_frames(sk); |
254 | out: | |
255 | return err; | |
256 | } | |
257 | ||
258 | struct icmpv6_msg { | |
259 | struct sk_buff *skb; | |
260 | int offset; | |
763ecff1 | 261 | uint8_t type; |
1da177e4 LT |
262 | }; |
263 | ||
264 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
265 | { | |
266 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
267 | struct sk_buff *org_skb = msg->skb; | |
5f92a738 | 268 | __wsum csum = 0; |
1da177e4 LT |
269 | |
270 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
271 | to, len, csum); | |
272 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
763ecff1 YK |
273 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
274 | nf_ct_attach(skb, org_skb); | |
1da177e4 LT |
275 | return 0; |
276 | } | |
277 | ||
59fbb3a6 | 278 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
79383236 MN |
279 | static void mip6_addr_swap(struct sk_buff *skb) |
280 | { | |
0660e03f | 281 | struct ipv6hdr *iph = ipv6_hdr(skb); |
79383236 MN |
282 | struct inet6_skb_parm *opt = IP6CB(skb); |
283 | struct ipv6_destopt_hao *hao; | |
284 | struct in6_addr tmp; | |
285 | int off; | |
286 | ||
287 | if (opt->dsthao) { | |
288 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
289 | if (likely(off >= 0)) { | |
d56f90a7 ACM |
290 | hao = (struct ipv6_destopt_hao *) |
291 | (skb_network_header(skb) + off); | |
79383236 MN |
292 | ipv6_addr_copy(&tmp, &iph->saddr); |
293 | ipv6_addr_copy(&iph->saddr, &hao->addr); | |
294 | ipv6_addr_copy(&hao->addr, &tmp); | |
295 | } | |
296 | } | |
297 | } | |
298 | #else | |
299 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
300 | #endif | |
301 | ||
1da177e4 LT |
302 | /* |
303 | * Send an ICMP message in response to a packet in error | |
304 | */ | |
1ab1457c | 305 | void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info, |
1da177e4 LT |
306 | struct net_device *dev) |
307 | { | |
c346dca1 | 308 | struct net *net = dev_net(skb->dev); |
1da177e4 | 309 | struct inet6_dev *idev = NULL; |
0660e03f | 310 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
84427d53 YH |
311 | struct sock *sk; |
312 | struct ipv6_pinfo *np; | |
1da177e4 LT |
313 | struct in6_addr *saddr = NULL; |
314 | struct dst_entry *dst; | |
8b7817f3 | 315 | struct dst_entry *dst2; |
1da177e4 LT |
316 | struct icmp6hdr tmp_hdr; |
317 | struct flowi fl; | |
8b7817f3 | 318 | struct flowi fl2; |
1da177e4 LT |
319 | struct icmpv6_msg msg; |
320 | int iif = 0; | |
321 | int addr_type = 0; | |
322 | int len; | |
41a1f8ea | 323 | int hlimit, tclass; |
1da177e4 LT |
324 | int err = 0; |
325 | ||
27a884dc ACM |
326 | if ((u8 *)hdr < skb->head || |
327 | (skb->network_header + sizeof(*hdr)) > skb->tail) | |
1da177e4 LT |
328 | return; |
329 | ||
330 | /* | |
1ab1457c | 331 | * Make sure we respect the rules |
1da177e4 LT |
332 | * i.e. RFC 1885 2.4(e) |
333 | * Rule (e.1) is enforced by not using icmpv6_send | |
334 | * in any code that processes icmp errors. | |
335 | */ | |
336 | addr_type = ipv6_addr_type(&hdr->daddr); | |
337 | ||
9a43b709 | 338 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
1da177e4 LT |
339 | saddr = &hdr->daddr; |
340 | ||
341 | /* | |
342 | * Dest addr check | |
343 | */ | |
344 | ||
345 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
346 | if (type != ICMPV6_PKT_TOOBIG && | |
1ab1457c YH |
347 | !(type == ICMPV6_PARAMPROB && |
348 | code == ICMPV6_UNK_OPTION && | |
1da177e4 LT |
349 | (opt_unrec(skb, info)))) |
350 | return; | |
351 | ||
352 | saddr = NULL; | |
353 | } | |
354 | ||
355 | addr_type = ipv6_addr_type(&hdr->saddr); | |
356 | ||
357 | /* | |
358 | * Source addr check | |
359 | */ | |
360 | ||
361 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
362 | iif = skb->dev->ifindex; | |
363 | ||
364 | /* | |
8de3351e YH |
365 | * Must not send error if the source does not uniquely |
366 | * identify a single node (RFC2463 Section 2.4). | |
367 | * We check unspecified / multicast addresses here, | |
368 | * and anycast addresses will be checked later. | |
1da177e4 LT |
369 | */ |
370 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 371 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
372 | return; |
373 | } | |
374 | ||
1ab1457c | 375 | /* |
1da177e4 LT |
376 | * Never answer to a ICMP packet. |
377 | */ | |
378 | if (is_ineligible(skb)) { | |
64ce2073 | 379 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
380 | return; |
381 | } | |
382 | ||
79383236 MN |
383 | mip6_addr_swap(skb); |
384 | ||
1da177e4 LT |
385 | memset(&fl, 0, sizeof(fl)); |
386 | fl.proto = IPPROTO_ICMPV6; | |
387 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); | |
388 | if (saddr) | |
389 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
390 | fl.oif = iif; | |
391 | fl.fl_icmp_type = type; | |
392 | fl.fl_icmp_code = code; | |
beb8d13b | 393 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 394 | |
9a43b709 | 395 | sk = icmpv6_sk(net); |
84427d53 YH |
396 | np = inet6_sk(sk); |
397 | ||
405666db DL |
398 | if (icmpv6_xmit_lock(sk)) |
399 | return; | |
400 | ||
1da177e4 LT |
401 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
402 | goto out; | |
403 | ||
404 | tmp_hdr.icmp6_type = type; | |
405 | tmp_hdr.icmp6_code = code; | |
406 | tmp_hdr.icmp6_cksum = 0; | |
407 | tmp_hdr.icmp6_pointer = htonl(info); | |
408 | ||
409 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) | |
410 | fl.oif = np->mcast_oif; | |
411 | ||
412 | err = ip6_dst_lookup(sk, &dst, &fl); | |
413 | if (err) | |
414 | goto out; | |
8de3351e YH |
415 | |
416 | /* | |
417 | * We won't send icmp if the destination is known | |
418 | * anycast. | |
419 | */ | |
420 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
421 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
422 | goto out_dst_release; | |
423 | } | |
424 | ||
8b7817f3 HX |
425 | /* No need to clone since we're just using its address. */ |
426 | dst2 = dst; | |
427 | ||
428 | err = xfrm_lookup(&dst, &fl, sk, 0); | |
429 | switch (err) { | |
430 | case 0: | |
431 | if (dst != dst2) | |
432 | goto route_done; | |
433 | break; | |
434 | case -EPERM: | |
435 | dst = NULL; | |
436 | break; | |
437 | default: | |
438 | goto out; | |
439 | } | |
440 | ||
441 | if (xfrm_decode_session_reverse(skb, &fl2, AF_INET6)) | |
af268182 | 442 | goto relookup_failed; |
8b7817f3 HX |
443 | |
444 | if (ip6_dst_lookup(sk, &dst2, &fl)) | |
af268182 | 445 | goto relookup_failed; |
1da177e4 | 446 | |
8b7817f3 | 447 | err = xfrm_lookup(&dst2, &fl, sk, XFRM_LOOKUP_ICMP); |
af268182 HX |
448 | switch (err) { |
449 | case 0: | |
450 | dst_release(dst); | |
451 | dst = dst2; | |
452 | break; | |
453 | case -EPERM: | |
454 | goto out_dst_release; | |
455 | default: | |
456 | relookup_failed: | |
8b7817f3 HX |
457 | if (!dst) |
458 | goto out; | |
af268182 | 459 | break; |
8b7817f3 HX |
460 | } |
461 | ||
8b7817f3 | 462 | route_done: |
1da177e4 LT |
463 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
464 | hlimit = np->mcast_hops; | |
465 | else | |
466 | hlimit = np->hop_limit; | |
467 | if (hlimit < 0) | |
6b75d090 | 468 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 | 469 | |
e012d51c | 470 | tclass = np->tclass; |
41a1f8ea YH |
471 | if (tclass < 0) |
472 | tclass = 0; | |
473 | ||
1da177e4 | 474 | msg.skb = skb; |
bbe735e4 | 475 | msg.offset = skb_network_offset(skb); |
763ecff1 | 476 | msg.type = type; |
1da177e4 LT |
477 | |
478 | len = skb->len - msg.offset; | |
479 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
480 | if (len < 0) { | |
64ce2073 | 481 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
482 | goto out_dst_release; |
483 | } | |
484 | ||
485 | idev = in6_dev_get(skb->dev); | |
486 | ||
487 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
488 | len + sizeof(struct icmp6hdr), | |
489 | sizeof(struct icmp6hdr), | |
41a1f8ea | 490 | hlimit, tclass, NULL, &fl, (struct rt6_info*)dst, |
1da177e4 LT |
491 | MSG_DONTWAIT); |
492 | if (err) { | |
493 | ip6_flush_pending_frames(sk); | |
494 | goto out_put; | |
495 | } | |
496 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
497 | ||
1da177e4 LT |
498 | out_put: |
499 | if (likely(idev != NULL)) | |
500 | in6_dev_put(idev); | |
501 | out_dst_release: | |
502 | dst_release(dst); | |
503 | out: | |
405666db | 504 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
505 | } |
506 | ||
7159039a YH |
507 | EXPORT_SYMBOL(icmpv6_send); |
508 | ||
1da177e4 LT |
509 | static void icmpv6_echo_reply(struct sk_buff *skb) |
510 | { | |
c346dca1 | 511 | struct net *net = dev_net(skb->dev); |
84427d53 | 512 | struct sock *sk; |
1da177e4 | 513 | struct inet6_dev *idev; |
84427d53 | 514 | struct ipv6_pinfo *np; |
1da177e4 | 515 | struct in6_addr *saddr = NULL; |
cc70ab26 | 516 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 LT |
517 | struct icmp6hdr tmp_hdr; |
518 | struct flowi fl; | |
519 | struct icmpv6_msg msg; | |
520 | struct dst_entry *dst; | |
521 | int err = 0; | |
522 | int hlimit; | |
41a1f8ea | 523 | int tclass; |
1da177e4 | 524 | |
0660e03f | 525 | saddr = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
526 | |
527 | if (!ipv6_unicast_destination(skb)) | |
528 | saddr = NULL; | |
529 | ||
530 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
531 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
532 | ||
533 | memset(&fl, 0, sizeof(fl)); | |
534 | fl.proto = IPPROTO_ICMPV6; | |
0660e03f | 535 | ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr); |
1da177e4 LT |
536 | if (saddr) |
537 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
538 | fl.oif = skb->dev->ifindex; | |
539 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; | |
beb8d13b | 540 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 541 | |
9a43b709 | 542 | sk = icmpv6_sk(net); |
84427d53 YH |
543 | np = inet6_sk(sk); |
544 | ||
405666db DL |
545 | if (icmpv6_xmit_lock(sk)) |
546 | return; | |
547 | ||
1da177e4 LT |
548 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
549 | fl.oif = np->mcast_oif; | |
550 | ||
551 | err = ip6_dst_lookup(sk, &dst, &fl); | |
552 | if (err) | |
553 | goto out; | |
554 | if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) | |
e104411b | 555 | goto out; |
1da177e4 LT |
556 | |
557 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
558 | hlimit = np->mcast_hops; | |
559 | else | |
560 | hlimit = np->hop_limit; | |
561 | if (hlimit < 0) | |
6b75d090 | 562 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 | 563 | |
e012d51c | 564 | tclass = np->tclass; |
41a1f8ea YH |
565 | if (tclass < 0) |
566 | tclass = 0; | |
567 | ||
1da177e4 LT |
568 | idev = in6_dev_get(skb->dev); |
569 | ||
570 | msg.skb = skb; | |
571 | msg.offset = 0; | |
763ecff1 | 572 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
573 | |
574 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
41a1f8ea | 575 | sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl, |
1da177e4 LT |
576 | (struct rt6_info*)dst, MSG_DONTWAIT); |
577 | ||
578 | if (err) { | |
579 | ip6_flush_pending_frames(sk); | |
580 | goto out_put; | |
581 | } | |
582 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
583 | ||
1ab1457c | 584 | out_put: |
1da177e4 LT |
585 | if (likely(idev != NULL)) |
586 | in6_dev_put(idev); | |
1da177e4 | 587 | dst_release(dst); |
1ab1457c | 588 | out: |
405666db | 589 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
590 | } |
591 | ||
04ce6909 | 592 | static void icmpv6_notify(struct sk_buff *skb, int type, int code, __be32 info) |
1da177e4 | 593 | { |
1da177e4 | 594 | struct inet6_protocol *ipprot; |
1da177e4 LT |
595 | int inner_offset; |
596 | int hash; | |
597 | u8 nexthdr; | |
598 | ||
599 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
600 | return; | |
601 | ||
602 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
603 | if (ipv6_ext_hdr(nexthdr)) { | |
604 | /* now skip over extension headers */ | |
0d3d077c | 605 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
606 | if (inner_offset<0) |
607 | return; | |
608 | } else { | |
609 | inner_offset = sizeof(struct ipv6hdr); | |
610 | } | |
611 | ||
612 | /* Checkin header including 8 bytes of inner protocol header. */ | |
613 | if (!pskb_may_pull(skb, inner_offset+8)) | |
614 | return; | |
615 | ||
1da177e4 LT |
616 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
617 | Without this we will not able f.e. to make source routed | |
618 | pmtu discovery. | |
619 | Corresponding argument (opt) to notifiers is already added. | |
620 | --ANK (980726) | |
621 | */ | |
622 | ||
623 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
624 | ||
625 | rcu_read_lock(); | |
626 | ipprot = rcu_dereference(inet6_protos[hash]); | |
627 | if (ipprot && ipprot->err_handler) | |
628 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
629 | rcu_read_unlock(); | |
630 | ||
69d6da0b | 631 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 632 | } |
1ab1457c | 633 | |
1da177e4 LT |
634 | /* |
635 | * Handle icmp messages | |
636 | */ | |
637 | ||
e5bbef20 | 638 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 639 | { |
1da177e4 LT |
640 | struct net_device *dev = skb->dev; |
641 | struct inet6_dev *idev = __in6_dev_get(dev); | |
642 | struct in6_addr *saddr, *daddr; | |
643 | struct ipv6hdr *orig_hdr; | |
644 | struct icmp6hdr *hdr; | |
645 | int type; | |
646 | ||
aebcf82c | 647 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
8b7817f3 HX |
648 | int nh; |
649 | ||
aebcf82c HX |
650 | if (!(skb->sp && skb->sp->xvec[skb->sp->len - 1]->props.flags & |
651 | XFRM_STATE_ICMP)) | |
652 | goto drop_no_count; | |
653 | ||
8b7817f3 HX |
654 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
655 | goto drop_no_count; | |
656 | ||
657 | nh = skb_network_offset(skb); | |
658 | skb_set_network_header(skb, sizeof(*hdr)); | |
659 | ||
660 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
661 | goto drop_no_count; | |
662 | ||
663 | skb_set_network_header(skb, nh); | |
664 | } | |
665 | ||
1da177e4 LT |
666 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INMSGS); |
667 | ||
0660e03f ACM |
668 | saddr = &ipv6_hdr(skb)->saddr; |
669 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
670 | |
671 | /* Perform checksum. */ | |
fb286bb2 | 672 | switch (skb->ip_summed) { |
84fa7933 | 673 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
674 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
675 | skb->csum)) | |
676 | break; | |
677 | /* fall through */ | |
678 | case CHECKSUM_NONE: | |
868c86bc AV |
679 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
680 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 681 | if (__skb_checksum_complete(skb)) { |
46b86a2d | 682 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [" NIP6_FMT " > " NIP6_FMT "]\n", |
64ce2073 | 683 | NIP6(*saddr), NIP6(*daddr)); |
1da177e4 LT |
684 | goto discard_it; |
685 | } | |
686 | } | |
687 | ||
8cf22943 HX |
688 | if (!pskb_pull(skb, sizeof(*hdr))) |
689 | goto discard_it; | |
1da177e4 | 690 | |
cc70ab26 | 691 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
692 | |
693 | type = hdr->icmp6_type; | |
694 | ||
14878f75 | 695 | ICMP6MSGIN_INC_STATS_BH(idev, type); |
1da177e4 LT |
696 | |
697 | switch (type) { | |
698 | case ICMPV6_ECHO_REQUEST: | |
699 | icmpv6_echo_reply(skb); | |
700 | break; | |
701 | ||
702 | case ICMPV6_ECHO_REPLY: | |
703 | /* we couldn't care less */ | |
704 | break; | |
705 | ||
706 | case ICMPV6_PKT_TOOBIG: | |
707 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
708 | standard destination cache. Seems, only "advanced" | |
709 | destination cache will allow to solve this problem | |
710 | --ANK (980726) | |
711 | */ | |
712 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
713 | goto discard_it; | |
cc70ab26 | 714 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
715 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
716 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
717 | ntohl(hdr->icmp6_mtu)); | |
718 | ||
719 | /* | |
720 | * Drop through to notify | |
721 | */ | |
722 | ||
723 | case ICMPV6_DEST_UNREACH: | |
724 | case ICMPV6_TIME_EXCEED: | |
725 | case ICMPV6_PARAMPROB: | |
726 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
727 | break; | |
728 | ||
729 | case NDISC_ROUTER_SOLICITATION: | |
730 | case NDISC_ROUTER_ADVERTISEMENT: | |
731 | case NDISC_NEIGHBOUR_SOLICITATION: | |
732 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
733 | case NDISC_REDIRECT: | |
734 | ndisc_rcv(skb); | |
735 | break; | |
736 | ||
737 | case ICMPV6_MGM_QUERY: | |
738 | igmp6_event_query(skb); | |
739 | break; | |
740 | ||
741 | case ICMPV6_MGM_REPORT: | |
742 | igmp6_event_report(skb); | |
743 | break; | |
744 | ||
745 | case ICMPV6_MGM_REDUCTION: | |
746 | case ICMPV6_NI_QUERY: | |
747 | case ICMPV6_NI_REPLY: | |
748 | case ICMPV6_MLD2_REPORT: | |
749 | case ICMPV6_DHAAD_REQUEST: | |
750 | case ICMPV6_DHAAD_REPLY: | |
751 | case ICMPV6_MOBILE_PREFIX_SOL: | |
752 | case ICMPV6_MOBILE_PREFIX_ADV: | |
753 | break; | |
754 | ||
755 | default: | |
64ce2073 | 756 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
757 | |
758 | /* informational */ | |
759 | if (type & ICMPV6_INFOMSG_MASK) | |
760 | break; | |
761 | ||
1ab1457c YH |
762 | /* |
763 | * error of unknown type. | |
764 | * must pass to upper level | |
1da177e4 LT |
765 | */ |
766 | ||
767 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
768 | } |
769 | ||
1da177e4 LT |
770 | kfree_skb(skb); |
771 | return 0; | |
772 | ||
773 | discard_it: | |
774 | ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS); | |
8b7817f3 | 775 | drop_no_count: |
1da177e4 LT |
776 | kfree_skb(skb); |
777 | return 0; | |
778 | } | |
779 | ||
95e41e93 YH |
780 | void icmpv6_flow_init(struct sock *sk, struct flowi *fl, |
781 | u8 type, | |
782 | const struct in6_addr *saddr, | |
783 | const struct in6_addr *daddr, | |
784 | int oif) | |
785 | { | |
786 | memset(fl, 0, sizeof(*fl)); | |
787 | ipv6_addr_copy(&fl->fl6_src, saddr); | |
788 | ipv6_addr_copy(&fl->fl6_dst, daddr); | |
789 | fl->proto = IPPROTO_ICMPV6; | |
790 | fl->fl_icmp_type = type; | |
791 | fl->fl_icmp_code = 0; | |
792 | fl->oif = oif; | |
793 | security_sk_classify_flow(sk, fl); | |
794 | } | |
795 | ||
640c41c7 | 796 | /* |
b7e729c4 | 797 | * Special lock-class for __icmpv6_sk: |
640c41c7 IM |
798 | */ |
799 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
800 | ||
98c6d1b2 | 801 | static int __net_init icmpv6_sk_init(struct net *net) |
1da177e4 LT |
802 | { |
803 | struct sock *sk; | |
804 | int err, i, j; | |
805 | ||
98c6d1b2 DL |
806 | net->ipv6.icmp_sk = |
807 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
808 | if (net->ipv6.icmp_sk == NULL) | |
79c91159 DL |
809 | return -ENOMEM; |
810 | ||
6f912042 | 811 | for_each_possible_cpu(i) { |
1ed8516f DL |
812 | err = inet_ctl_sock_create(&sk, PF_INET6, |
813 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
1da177e4 LT |
814 | if (err < 0) { |
815 | printk(KERN_ERR | |
816 | "Failed to initialize the ICMP6 control socket " | |
817 | "(err %d).\n", | |
818 | err); | |
819 | goto fail; | |
820 | } | |
821 | ||
1ed8516f | 822 | net->ipv6.icmp_sk[i] = sk; |
5c8cafd6 | 823 | |
640c41c7 IM |
824 | /* |
825 | * Split off their lock-class, because sk->sk_dst_lock | |
826 | * gets used from softirqs, which is safe for | |
b7e729c4 | 827 | * __icmpv6_sk (because those never get directly used |
640c41c7 IM |
828 | * via userspace syscalls), but unsafe for normal sockets. |
829 | */ | |
830 | lockdep_set_class(&sk->sk_dst_lock, | |
831 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
832 | |
833 | /* Enough space for 2 64K ICMP packets, including | |
834 | * sk_buff struct overhead. | |
835 | */ | |
836 | sk->sk_sndbuf = | |
837 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
1da177e4 | 838 | } |
1da177e4 LT |
839 | return 0; |
840 | ||
841 | fail: | |
5c8cafd6 | 842 | for (j = 0; j < i; j++) |
1ed8516f | 843 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
98c6d1b2 | 844 | kfree(net->ipv6.icmp_sk); |
1da177e4 LT |
845 | return err; |
846 | } | |
847 | ||
98c6d1b2 | 848 | static void __net_exit icmpv6_sk_exit(struct net *net) |
1da177e4 LT |
849 | { |
850 | int i; | |
851 | ||
6f912042 | 852 | for_each_possible_cpu(i) { |
1ed8516f | 853 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
1da177e4 | 854 | } |
98c6d1b2 DL |
855 | kfree(net->ipv6.icmp_sk); |
856 | } | |
857 | ||
8ed7edce | 858 | static struct pernet_operations icmpv6_sk_ops = { |
98c6d1b2 DL |
859 | .init = icmpv6_sk_init, |
860 | .exit = icmpv6_sk_exit, | |
861 | }; | |
862 | ||
863 | int __init icmpv6_init(void) | |
864 | { | |
865 | int err; | |
866 | ||
867 | err = register_pernet_subsys(&icmpv6_sk_ops); | |
868 | if (err < 0) | |
869 | return err; | |
870 | ||
871 | err = -EAGAIN; | |
872 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) | |
873 | goto fail; | |
874 | return 0; | |
875 | ||
876 | fail: | |
877 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
878 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
879 | return err; | |
880 | } | |
881 | ||
8ed7edce | 882 | void icmpv6_cleanup(void) |
98c6d1b2 DL |
883 | { |
884 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
1da177e4 LT |
885 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
886 | } | |
887 | ||
98c6d1b2 | 888 | |
9b5b5cff | 889 | static const struct icmp6_err { |
1da177e4 LT |
890 | int err; |
891 | int fatal; | |
892 | } tab_unreach[] = { | |
893 | { /* NOROUTE */ | |
894 | .err = ENETUNREACH, | |
895 | .fatal = 0, | |
896 | }, | |
897 | { /* ADM_PROHIBITED */ | |
898 | .err = EACCES, | |
899 | .fatal = 1, | |
900 | }, | |
901 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
902 | .err = EHOSTUNREACH, | |
903 | .fatal = 0, | |
904 | }, | |
905 | { /* ADDR_UNREACH */ | |
906 | .err = EHOSTUNREACH, | |
907 | .fatal = 0, | |
908 | }, | |
909 | { /* PORT_UNREACH */ | |
910 | .err = ECONNREFUSED, | |
911 | .fatal = 1, | |
912 | }, | |
913 | }; | |
914 | ||
915 | int icmpv6_err_convert(int type, int code, int *err) | |
916 | { | |
917 | int fatal = 0; | |
918 | ||
919 | *err = EPROTO; | |
920 | ||
921 | switch (type) { | |
922 | case ICMPV6_DEST_UNREACH: | |
923 | fatal = 1; | |
924 | if (code <= ICMPV6_PORT_UNREACH) { | |
925 | *err = tab_unreach[code].err; | |
926 | fatal = tab_unreach[code].fatal; | |
927 | } | |
928 | break; | |
929 | ||
930 | case ICMPV6_PKT_TOOBIG: | |
931 | *err = EMSGSIZE; | |
932 | break; | |
1ab1457c | 933 | |
1da177e4 LT |
934 | case ICMPV6_PARAMPROB: |
935 | *err = EPROTO; | |
936 | fatal = 1; | |
937 | break; | |
938 | ||
939 | case ICMPV6_TIME_EXCEED: | |
940 | *err = EHOSTUNREACH; | |
941 | break; | |
3ff50b79 | 942 | } |
1da177e4 LT |
943 | |
944 | return fatal; | |
945 | } | |
946 | ||
7159039a YH |
947 | EXPORT_SYMBOL(icmpv6_err_convert); |
948 | ||
1da177e4 | 949 | #ifdef CONFIG_SYSCTL |
760f2d01 | 950 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 LT |
951 | { |
952 | .ctl_name = NET_IPV6_ICMP_RATELIMIT, | |
953 | .procname = "ratelimit", | |
41a76906 | 954 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
955 | .maxlen = sizeof(int), |
956 | .mode = 0644, | |
957 | .proc_handler = &proc_dointvec | |
958 | }, | |
959 | { .ctl_name = 0 }, | |
960 | }; | |
760f2d01 DL |
961 | |
962 | struct ctl_table *ipv6_icmp_sysctl_init(struct net *net) | |
963 | { | |
964 | struct ctl_table *table; | |
965 | ||
966 | table = kmemdup(ipv6_icmp_table_template, | |
967 | sizeof(ipv6_icmp_table_template), | |
968 | GFP_KERNEL); | |
5ee09105 YH |
969 | |
970 | if (table) | |
971 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
972 | ||
760f2d01 DL |
973 | return table; |
974 | } | |
1da177e4 LT |
975 | #endif |
976 |