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> |
5a0e3ad6 | 43 | #include <linux/slab.h> |
1da177e4 LT |
44 | |
45 | #ifdef CONFIG_SYSCTL | |
46 | #include <linux/sysctl.h> | |
47 | #endif | |
48 | ||
49 | #include <linux/inet.h> | |
50 | #include <linux/netdevice.h> | |
51 | #include <linux/icmpv6.h> | |
52 | ||
53 | #include <net/ip.h> | |
54 | #include <net/sock.h> | |
55 | ||
56 | #include <net/ipv6.h> | |
57 | #include <net/ip6_checksum.h> | |
58 | #include <net/protocol.h> | |
59 | #include <net/raw.h> | |
60 | #include <net/rawv6.h> | |
61 | #include <net/transp_v6.h> | |
62 | #include <net/ip6_route.h> | |
63 | #include <net/addrconf.h> | |
64 | #include <net/icmp.h> | |
8b7817f3 | 65 | #include <net/xfrm.h> |
1ed8516f | 66 | #include <net/inet_common.h> |
1da177e4 LT |
67 | |
68 | #include <asm/uaccess.h> | |
69 | #include <asm/system.h> | |
70 | ||
1da177e4 LT |
71 | /* |
72 | * The ICMP socket(s). This is the most convenient way to flow control | |
73 | * our ICMP output as well as maintain a clean interface throughout | |
74 | * all layers. All Socketless IP sends will soon be gone. | |
75 | * | |
76 | * On SMP we have one ICMP socket per-cpu. | |
77 | */ | |
98c6d1b2 DL |
78 | static inline struct sock *icmpv6_sk(struct net *net) |
79 | { | |
80 | return net->ipv6.icmp_sk[smp_processor_id()]; | |
81 | } | |
1da177e4 | 82 | |
e5bbef20 | 83 | static int icmpv6_rcv(struct sk_buff *skb); |
1da177e4 | 84 | |
41135cc8 | 85 | static const struct inet6_protocol icmpv6_protocol = { |
1da177e4 | 86 | .handler = icmpv6_rcv, |
8b7817f3 | 87 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
1da177e4 LT |
88 | }; |
89 | ||
fdc0bde9 | 90 | static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) |
1da177e4 | 91 | { |
fdc0bde9 DL |
92 | struct sock *sk; |
93 | ||
1da177e4 LT |
94 | local_bh_disable(); |
95 | ||
fdc0bde9 | 96 | sk = icmpv6_sk(net); |
405666db | 97 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
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(); | |
fdc0bde9 | 103 | return NULL; |
1da177e4 | 104 | } |
fdc0bde9 | 105 | return sk; |
1da177e4 LT |
106 | } |
107 | ||
405666db | 108 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
1da177e4 | 109 | { |
405666db | 110 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
111 | } |
112 | ||
1ab1457c | 113 | /* |
1da177e4 LT |
114 | * Slightly more convenient version of icmpv6_send. |
115 | */ | |
d5fdd6ba | 116 | void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) |
1da177e4 | 117 | { |
3ffe533c | 118 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos); |
1da177e4 LT |
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 | 159 | */ |
92d86829 DM |
160 | static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
161 | struct flowi *fl) | |
1da177e4 LT |
162 | { |
163 | struct dst_entry *dst; | |
3b1e0a65 | 164 | struct net *net = sock_net(sk); |
92d86829 | 165 | bool res = false; |
1da177e4 LT |
166 | |
167 | /* Informational messages are not limited. */ | |
168 | if (type & ICMPV6_INFOMSG_MASK) | |
92d86829 | 169 | return true; |
1da177e4 LT |
170 | |
171 | /* Do not limit pmtu discovery, it would break it. */ | |
172 | if (type == ICMPV6_PKT_TOOBIG) | |
92d86829 | 173 | return true; |
1da177e4 | 174 | |
1ab1457c | 175 | /* |
1da177e4 LT |
176 | * Look up the output route. |
177 | * XXX: perhaps the expire for routing entries cloned by | |
178 | * this lookup should be more aggressive (not longer than timeout). | |
179 | */ | |
9a43b709 | 180 | dst = ip6_route_output(net, sk, fl); |
1da177e4 | 181 | if (dst->error) { |
3bd653c8 | 182 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
a11d206d | 183 | IPSTATS_MIB_OUTNOROUTES); |
1da177e4 | 184 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
92d86829 | 185 | res = true; |
1da177e4 LT |
186 | } else { |
187 | struct rt6_info *rt = (struct rt6_info *)dst; | |
9a43b709 | 188 | int tmo = net->ipv6.sysctl.icmpv6_time; |
1da177e4 LT |
189 | |
190 | /* Give more bandwidth to wider prefixes. */ | |
191 | if (rt->rt6i_dst.plen < 128) | |
192 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); | |
193 | ||
92d86829 DM |
194 | if (!rt->rt6i_peer) |
195 | rt6_bind_peer(rt, 1); | |
196 | res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo); | |
1da177e4 LT |
197 | } |
198 | dst_release(dst); | |
199 | return res; | |
200 | } | |
201 | ||
202 | /* | |
203 | * an inline helper for the "simple" if statement below | |
204 | * checks if parameter problem report is caused by an | |
1ab1457c | 205 | * unrecognized IPv6 option that has the Option Type |
1da177e4 LT |
206 | * highest-order two bits set to 10 |
207 | */ | |
208 | ||
209 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) | |
210 | { | |
211 | u8 _optval, *op; | |
212 | ||
bbe735e4 | 213 | offset += skb_network_offset(skb); |
1da177e4 LT |
214 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
215 | if (op == NULL) | |
216 | return 1; | |
217 | return (*op & 0xC0) == 0x80; | |
218 | } | |
219 | ||
220 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi *fl, struct icmp6hdr *thdr, int len) | |
221 | { | |
222 | struct sk_buff *skb; | |
223 | struct icmp6hdr *icmp6h; | |
224 | int err = 0; | |
225 | ||
226 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
227 | goto out; | |
228 | ||
cc70ab26 | 229 | icmp6h = icmp6_hdr(skb); |
1da177e4 LT |
230 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
231 | icmp6h->icmp6_cksum = 0; | |
232 | ||
233 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
07f0757a | 234 | skb->csum = csum_partial(icmp6h, |
1da177e4 LT |
235 | sizeof(struct icmp6hdr), skb->csum); |
236 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, | |
237 | &fl->fl6_dst, | |
238 | len, fl->proto, | |
239 | skb->csum); | |
240 | } else { | |
868c86bc | 241 | __wsum tmp_csum = 0; |
1da177e4 LT |
242 | |
243 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
244 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
245 | } | |
246 | ||
07f0757a | 247 | tmp_csum = csum_partial(icmp6h, |
1da177e4 | 248 | sizeof(struct icmp6hdr), tmp_csum); |
868c86bc AV |
249 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl->fl6_src, |
250 | &fl->fl6_dst, | |
251 | len, fl->proto, | |
252 | tmp_csum); | |
1da177e4 | 253 | } |
1da177e4 LT |
254 | ip6_push_pending_frames(sk); |
255 | out: | |
256 | return err; | |
257 | } | |
258 | ||
259 | struct icmpv6_msg { | |
260 | struct sk_buff *skb; | |
261 | int offset; | |
763ecff1 | 262 | uint8_t type; |
1da177e4 LT |
263 | }; |
264 | ||
265 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
266 | { | |
267 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
268 | struct sk_buff *org_skb = msg->skb; | |
5f92a738 | 269 | __wsum csum = 0; |
1da177e4 LT |
270 | |
271 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
272 | to, len, csum); | |
273 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
763ecff1 YK |
274 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
275 | nf_ct_attach(skb, org_skb); | |
1da177e4 LT |
276 | return 0; |
277 | } | |
278 | ||
59fbb3a6 | 279 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
79383236 MN |
280 | static void mip6_addr_swap(struct sk_buff *skb) |
281 | { | |
0660e03f | 282 | struct ipv6hdr *iph = ipv6_hdr(skb); |
79383236 MN |
283 | struct inet6_skb_parm *opt = IP6CB(skb); |
284 | struct ipv6_destopt_hao *hao; | |
285 | struct in6_addr tmp; | |
286 | int off; | |
287 | ||
288 | if (opt->dsthao) { | |
289 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
290 | if (likely(off >= 0)) { | |
d56f90a7 ACM |
291 | hao = (struct ipv6_destopt_hao *) |
292 | (skb_network_header(skb) + off); | |
79383236 MN |
293 | ipv6_addr_copy(&tmp, &iph->saddr); |
294 | ipv6_addr_copy(&iph->saddr, &hao->addr); | |
295 | ipv6_addr_copy(&hao->addr, &tmp); | |
296 | } | |
297 | } | |
298 | } | |
299 | #else | |
300 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
301 | #endif | |
302 | ||
b42835db DM |
303 | static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb, |
304 | struct sock *sk, struct flowi *fl) | |
305 | { | |
306 | struct dst_entry *dst, *dst2; | |
307 | struct flowi fl2; | |
308 | int err; | |
309 | ||
310 | err = ip6_dst_lookup(sk, &dst, fl); | |
311 | if (err) | |
312 | return ERR_PTR(err); | |
313 | ||
314 | /* | |
315 | * We won't send icmp if the destination is known | |
316 | * anycast. | |
317 | */ | |
318 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
319 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
320 | dst_release(dst); | |
321 | return ERR_PTR(-EINVAL); | |
322 | } | |
323 | ||
324 | /* No need to clone since we're just using its address. */ | |
325 | dst2 = dst; | |
326 | ||
327 | err = xfrm_lookup(net, &dst, fl, sk, 0); | |
328 | switch (err) { | |
329 | case 0: | |
330 | if (dst != dst2) | |
331 | return dst; | |
332 | break; | |
333 | case -EPERM: | |
334 | dst = NULL; | |
335 | break; | |
336 | default: | |
337 | return ERR_PTR(err); | |
338 | } | |
339 | ||
340 | err = xfrm_decode_session_reverse(skb, &fl2, AF_INET6); | |
341 | if (err) | |
342 | goto relookup_failed; | |
343 | ||
344 | err = ip6_dst_lookup(sk, &dst2, &fl2); | |
345 | if (err) | |
346 | goto relookup_failed; | |
347 | ||
348 | err = xfrm_lookup(net, &dst2, &fl2, sk, XFRM_LOOKUP_ICMP); | |
349 | switch (err) { | |
350 | case 0: | |
351 | dst_release(dst); | |
352 | dst = dst2; | |
353 | break; | |
354 | case -EPERM: | |
355 | dst_release(dst); | |
356 | return ERR_PTR(err); | |
357 | default: | |
358 | goto relookup_failed; | |
359 | } | |
360 | ||
361 | relookup_failed: | |
362 | if (dst) | |
363 | return dst; | |
364 | return ERR_PTR(err); | |
365 | } | |
366 | ||
1da177e4 LT |
367 | /* |
368 | * Send an ICMP message in response to a packet in error | |
369 | */ | |
3ffe533c | 370 | void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) |
1da177e4 | 371 | { |
c346dca1 | 372 | struct net *net = dev_net(skb->dev); |
1da177e4 | 373 | struct inet6_dev *idev = NULL; |
0660e03f | 374 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
84427d53 YH |
375 | struct sock *sk; |
376 | struct ipv6_pinfo *np; | |
1da177e4 LT |
377 | struct in6_addr *saddr = NULL; |
378 | struct dst_entry *dst; | |
379 | struct icmp6hdr tmp_hdr; | |
380 | struct flowi fl; | |
381 | struct icmpv6_msg msg; | |
382 | int iif = 0; | |
383 | int addr_type = 0; | |
384 | int len; | |
e651f03a | 385 | int hlimit; |
1da177e4 LT |
386 | int err = 0; |
387 | ||
27a884dc ACM |
388 | if ((u8 *)hdr < skb->head || |
389 | (skb->network_header + sizeof(*hdr)) > skb->tail) | |
1da177e4 LT |
390 | return; |
391 | ||
392 | /* | |
1ab1457c | 393 | * Make sure we respect the rules |
1da177e4 LT |
394 | * i.e. RFC 1885 2.4(e) |
395 | * Rule (e.1) is enforced by not using icmpv6_send | |
396 | * in any code that processes icmp errors. | |
397 | */ | |
398 | addr_type = ipv6_addr_type(&hdr->daddr); | |
399 | ||
9a43b709 | 400 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
1da177e4 LT |
401 | saddr = &hdr->daddr; |
402 | ||
403 | /* | |
404 | * Dest addr check | |
405 | */ | |
406 | ||
407 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
408 | if (type != ICMPV6_PKT_TOOBIG && | |
1ab1457c YH |
409 | !(type == ICMPV6_PARAMPROB && |
410 | code == ICMPV6_UNK_OPTION && | |
1da177e4 LT |
411 | (opt_unrec(skb, info)))) |
412 | return; | |
413 | ||
414 | saddr = NULL; | |
415 | } | |
416 | ||
417 | addr_type = ipv6_addr_type(&hdr->saddr); | |
418 | ||
419 | /* | |
420 | * Source addr check | |
421 | */ | |
422 | ||
423 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
424 | iif = skb->dev->ifindex; | |
425 | ||
426 | /* | |
8de3351e YH |
427 | * Must not send error if the source does not uniquely |
428 | * identify a single node (RFC2463 Section 2.4). | |
429 | * We check unspecified / multicast addresses here, | |
430 | * and anycast addresses will be checked later. | |
1da177e4 LT |
431 | */ |
432 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 433 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
434 | return; |
435 | } | |
436 | ||
1ab1457c | 437 | /* |
1da177e4 LT |
438 | * Never answer to a ICMP packet. |
439 | */ | |
440 | if (is_ineligible(skb)) { | |
64ce2073 | 441 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
442 | return; |
443 | } | |
444 | ||
79383236 MN |
445 | mip6_addr_swap(skb); |
446 | ||
1da177e4 LT |
447 | memset(&fl, 0, sizeof(fl)); |
448 | fl.proto = IPPROTO_ICMPV6; | |
449 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); | |
450 | if (saddr) | |
451 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
452 | fl.oif = iif; | |
453 | fl.fl_icmp_type = type; | |
454 | fl.fl_icmp_code = code; | |
beb8d13b | 455 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 456 | |
fdc0bde9 DL |
457 | sk = icmpv6_xmit_lock(net); |
458 | if (sk == NULL) | |
405666db | 459 | return; |
fdc0bde9 | 460 | np = inet6_sk(sk); |
405666db | 461 | |
1da177e4 LT |
462 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
463 | goto out; | |
464 | ||
465 | tmp_hdr.icmp6_type = type; | |
466 | tmp_hdr.icmp6_code = code; | |
467 | tmp_hdr.icmp6_cksum = 0; | |
468 | tmp_hdr.icmp6_pointer = htonl(info); | |
469 | ||
470 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) | |
471 | fl.oif = np->mcast_oif; | |
472 | ||
b42835db DM |
473 | dst = icmpv6_route_lookup(net, skb, sk, &fl); |
474 | if (IS_ERR(dst)) | |
1da177e4 | 475 | goto out; |
8de3351e | 476 | |
1da177e4 LT |
477 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
478 | hlimit = np->mcast_hops; | |
479 | else | |
480 | hlimit = np->hop_limit; | |
481 | if (hlimit < 0) | |
6b75d090 | 482 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
483 | |
484 | msg.skb = skb; | |
bbe735e4 | 485 | msg.offset = skb_network_offset(skb); |
763ecff1 | 486 | msg.type = type; |
1da177e4 LT |
487 | |
488 | len = skb->len - msg.offset; | |
489 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
490 | if (len < 0) { | |
64ce2073 | 491 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
492 | goto out_dst_release; |
493 | } | |
494 | ||
495 | idev = in6_dev_get(skb->dev); | |
496 | ||
497 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
498 | len + sizeof(struct icmp6hdr), | |
e651f03a GR |
499 | sizeof(struct icmp6hdr), hlimit, |
500 | np->tclass, NULL, &fl, (struct rt6_info*)dst, | |
13b52cd4 | 501 | MSG_DONTWAIT, np->dontfrag); |
1da177e4 | 502 | if (err) { |
00d9d6a1 | 503 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 LT |
504 | ip6_flush_pending_frames(sk); |
505 | goto out_put; | |
506 | } | |
507 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
508 | ||
1da177e4 LT |
509 | out_put: |
510 | if (likely(idev != NULL)) | |
511 | in6_dev_put(idev); | |
512 | out_dst_release: | |
513 | dst_release(dst); | |
514 | out: | |
405666db | 515 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
516 | } |
517 | ||
7159039a YH |
518 | EXPORT_SYMBOL(icmpv6_send); |
519 | ||
1da177e4 LT |
520 | static void icmpv6_echo_reply(struct sk_buff *skb) |
521 | { | |
c346dca1 | 522 | struct net *net = dev_net(skb->dev); |
84427d53 | 523 | struct sock *sk; |
1da177e4 | 524 | struct inet6_dev *idev; |
84427d53 | 525 | struct ipv6_pinfo *np; |
1da177e4 | 526 | struct in6_addr *saddr = NULL; |
cc70ab26 | 527 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 LT |
528 | struct icmp6hdr tmp_hdr; |
529 | struct flowi fl; | |
530 | struct icmpv6_msg msg; | |
531 | struct dst_entry *dst; | |
532 | int err = 0; | |
533 | int hlimit; | |
534 | ||
0660e03f | 535 | saddr = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
536 | |
537 | if (!ipv6_unicast_destination(skb)) | |
538 | saddr = NULL; | |
539 | ||
540 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
541 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
542 | ||
543 | memset(&fl, 0, sizeof(fl)); | |
544 | fl.proto = IPPROTO_ICMPV6; | |
0660e03f | 545 | ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr); |
1da177e4 LT |
546 | if (saddr) |
547 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
548 | fl.oif = skb->dev->ifindex; | |
549 | fl.fl_icmp_type = ICMPV6_ECHO_REPLY; | |
beb8d13b | 550 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 551 | |
fdc0bde9 DL |
552 | sk = icmpv6_xmit_lock(net); |
553 | if (sk == NULL) | |
405666db | 554 | return; |
fdc0bde9 | 555 | np = inet6_sk(sk); |
405666db | 556 | |
1da177e4 LT |
557 | if (!fl.oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
558 | fl.oif = np->mcast_oif; | |
559 | ||
560 | err = ip6_dst_lookup(sk, &dst, &fl); | |
561 | if (err) | |
562 | goto out; | |
52479b62 | 563 | if ((err = xfrm_lookup(net, &dst, &fl, sk, 0)) < 0) |
e104411b | 564 | goto out; |
1da177e4 LT |
565 | |
566 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
567 | hlimit = np->mcast_hops; | |
568 | else | |
569 | hlimit = np->hop_limit; | |
570 | if (hlimit < 0) | |
6b75d090 | 571 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
572 | |
573 | idev = in6_dev_get(skb->dev); | |
574 | ||
575 | msg.skb = skb; | |
576 | msg.offset = 0; | |
763ecff1 | 577 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
578 | |
579 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
e651f03a | 580 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl, |
13b52cd4 BH |
581 | (struct rt6_info*)dst, MSG_DONTWAIT, |
582 | np->dontfrag); | |
1da177e4 LT |
583 | |
584 | if (err) { | |
00d9d6a1 | 585 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 LT |
586 | ip6_flush_pending_frames(sk); |
587 | goto out_put; | |
588 | } | |
589 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
590 | ||
1ab1457c | 591 | out_put: |
1da177e4 LT |
592 | if (likely(idev != NULL)) |
593 | in6_dev_put(idev); | |
1da177e4 | 594 | dst_release(dst); |
1ab1457c | 595 | out: |
405666db | 596 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
597 | } |
598 | ||
d5fdd6ba | 599 | static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
1da177e4 | 600 | { |
41135cc8 | 601 | const struct inet6_protocol *ipprot; |
1da177e4 LT |
602 | int inner_offset; |
603 | int hash; | |
604 | u8 nexthdr; | |
605 | ||
606 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
607 | return; | |
608 | ||
609 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
610 | if (ipv6_ext_hdr(nexthdr)) { | |
611 | /* now skip over extension headers */ | |
0d3d077c | 612 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
613 | if (inner_offset<0) |
614 | return; | |
615 | } else { | |
616 | inner_offset = sizeof(struct ipv6hdr); | |
617 | } | |
618 | ||
619 | /* Checkin header including 8 bytes of inner protocol header. */ | |
620 | if (!pskb_may_pull(skb, inner_offset+8)) | |
621 | return; | |
622 | ||
1da177e4 LT |
623 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
624 | Without this we will not able f.e. to make source routed | |
625 | pmtu discovery. | |
626 | Corresponding argument (opt) to notifiers is already added. | |
627 | --ANK (980726) | |
628 | */ | |
629 | ||
630 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
631 | ||
632 | rcu_read_lock(); | |
633 | ipprot = rcu_dereference(inet6_protos[hash]); | |
634 | if (ipprot && ipprot->err_handler) | |
635 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
636 | rcu_read_unlock(); | |
637 | ||
69d6da0b | 638 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 639 | } |
1ab1457c | 640 | |
1da177e4 LT |
641 | /* |
642 | * Handle icmp messages | |
643 | */ | |
644 | ||
e5bbef20 | 645 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 646 | { |
1da177e4 LT |
647 | struct net_device *dev = skb->dev; |
648 | struct inet6_dev *idev = __in6_dev_get(dev); | |
649 | struct in6_addr *saddr, *daddr; | |
650 | struct ipv6hdr *orig_hdr; | |
651 | struct icmp6hdr *hdr; | |
d5fdd6ba | 652 | u8 type; |
1da177e4 | 653 | |
aebcf82c | 654 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 655 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
656 | int nh; |
657 | ||
def8b4fa | 658 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
659 | XFRM_STATE_ICMP)) |
660 | goto drop_no_count; | |
661 | ||
8b7817f3 HX |
662 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
663 | goto drop_no_count; | |
664 | ||
665 | nh = skb_network_offset(skb); | |
666 | skb_set_network_header(skb, sizeof(*hdr)); | |
667 | ||
668 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
669 | goto drop_no_count; | |
670 | ||
671 | skb_set_network_header(skb, nh); | |
672 | } | |
673 | ||
e41b5368 | 674 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
1da177e4 | 675 | |
0660e03f ACM |
676 | saddr = &ipv6_hdr(skb)->saddr; |
677 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
678 | |
679 | /* Perform checksum. */ | |
fb286bb2 | 680 | switch (skb->ip_summed) { |
84fa7933 | 681 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
682 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
683 | skb->csum)) | |
684 | break; | |
685 | /* fall through */ | |
686 | case CHECKSUM_NONE: | |
868c86bc AV |
687 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
688 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 689 | if (__skb_checksum_complete(skb)) { |
5b095d98 | 690 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", |
0c6ce78a | 691 | saddr, daddr); |
1da177e4 LT |
692 | goto discard_it; |
693 | } | |
694 | } | |
695 | ||
8cf22943 HX |
696 | if (!pskb_pull(skb, sizeof(*hdr))) |
697 | goto discard_it; | |
1da177e4 | 698 | |
cc70ab26 | 699 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
700 | |
701 | type = hdr->icmp6_type; | |
702 | ||
55d43808 | 703 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
1da177e4 LT |
704 | |
705 | switch (type) { | |
706 | case ICMPV6_ECHO_REQUEST: | |
707 | icmpv6_echo_reply(skb); | |
708 | break; | |
709 | ||
710 | case ICMPV6_ECHO_REPLY: | |
711 | /* we couldn't care less */ | |
712 | break; | |
713 | ||
714 | case ICMPV6_PKT_TOOBIG: | |
715 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
716 | standard destination cache. Seems, only "advanced" | |
717 | destination cache will allow to solve this problem | |
718 | --ANK (980726) | |
719 | */ | |
720 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
721 | goto discard_it; | |
cc70ab26 | 722 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
723 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
724 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
725 | ntohl(hdr->icmp6_mtu)); | |
726 | ||
727 | /* | |
728 | * Drop through to notify | |
729 | */ | |
730 | ||
731 | case ICMPV6_DEST_UNREACH: | |
732 | case ICMPV6_TIME_EXCEED: | |
733 | case ICMPV6_PARAMPROB: | |
734 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
735 | break; | |
736 | ||
737 | case NDISC_ROUTER_SOLICITATION: | |
738 | case NDISC_ROUTER_ADVERTISEMENT: | |
739 | case NDISC_NEIGHBOUR_SOLICITATION: | |
740 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
741 | case NDISC_REDIRECT: | |
742 | ndisc_rcv(skb); | |
743 | break; | |
744 | ||
745 | case ICMPV6_MGM_QUERY: | |
746 | igmp6_event_query(skb); | |
747 | break; | |
748 | ||
749 | case ICMPV6_MGM_REPORT: | |
750 | igmp6_event_report(skb); | |
751 | break; | |
752 | ||
753 | case ICMPV6_MGM_REDUCTION: | |
754 | case ICMPV6_NI_QUERY: | |
755 | case ICMPV6_NI_REPLY: | |
756 | case ICMPV6_MLD2_REPORT: | |
757 | case ICMPV6_DHAAD_REQUEST: | |
758 | case ICMPV6_DHAAD_REPLY: | |
759 | case ICMPV6_MOBILE_PREFIX_SOL: | |
760 | case ICMPV6_MOBILE_PREFIX_ADV: | |
761 | break; | |
762 | ||
763 | default: | |
64ce2073 | 764 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
765 | |
766 | /* informational */ | |
767 | if (type & ICMPV6_INFOMSG_MASK) | |
768 | break; | |
769 | ||
1ab1457c YH |
770 | /* |
771 | * error of unknown type. | |
772 | * must pass to upper level | |
1da177e4 LT |
773 | */ |
774 | ||
775 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
776 | } |
777 | ||
1da177e4 LT |
778 | kfree_skb(skb); |
779 | return 0; | |
780 | ||
781 | discard_it: | |
e41b5368 | 782 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
8b7817f3 | 783 | drop_no_count: |
1da177e4 LT |
784 | kfree_skb(skb); |
785 | return 0; | |
786 | } | |
787 | ||
95e41e93 YH |
788 | void icmpv6_flow_init(struct sock *sk, struct flowi *fl, |
789 | u8 type, | |
790 | const struct in6_addr *saddr, | |
791 | const struct in6_addr *daddr, | |
792 | int oif) | |
793 | { | |
794 | memset(fl, 0, sizeof(*fl)); | |
795 | ipv6_addr_copy(&fl->fl6_src, saddr); | |
796 | ipv6_addr_copy(&fl->fl6_dst, daddr); | |
797 | fl->proto = IPPROTO_ICMPV6; | |
798 | fl->fl_icmp_type = type; | |
799 | fl->fl_icmp_code = 0; | |
800 | fl->oif = oif; | |
801 | security_sk_classify_flow(sk, fl); | |
802 | } | |
803 | ||
640c41c7 | 804 | /* |
b7e729c4 | 805 | * Special lock-class for __icmpv6_sk: |
640c41c7 IM |
806 | */ |
807 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
808 | ||
98c6d1b2 | 809 | static int __net_init icmpv6_sk_init(struct net *net) |
1da177e4 LT |
810 | { |
811 | struct sock *sk; | |
812 | int err, i, j; | |
813 | ||
98c6d1b2 DL |
814 | net->ipv6.icmp_sk = |
815 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
816 | if (net->ipv6.icmp_sk == NULL) | |
79c91159 DL |
817 | return -ENOMEM; |
818 | ||
6f912042 | 819 | for_each_possible_cpu(i) { |
1ed8516f DL |
820 | err = inet_ctl_sock_create(&sk, PF_INET6, |
821 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
1da177e4 LT |
822 | if (err < 0) { |
823 | printk(KERN_ERR | |
824 | "Failed to initialize the ICMP6 control socket " | |
825 | "(err %d).\n", | |
826 | err); | |
827 | goto fail; | |
828 | } | |
829 | ||
1ed8516f | 830 | net->ipv6.icmp_sk[i] = sk; |
5c8cafd6 | 831 | |
640c41c7 IM |
832 | /* |
833 | * Split off their lock-class, because sk->sk_dst_lock | |
834 | * gets used from softirqs, which is safe for | |
b7e729c4 | 835 | * __icmpv6_sk (because those never get directly used |
640c41c7 IM |
836 | * via userspace syscalls), but unsafe for normal sockets. |
837 | */ | |
838 | lockdep_set_class(&sk->sk_dst_lock, | |
839 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
840 | |
841 | /* Enough space for 2 64K ICMP packets, including | |
842 | * sk_buff struct overhead. | |
843 | */ | |
844 | sk->sk_sndbuf = | |
845 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
1da177e4 | 846 | } |
1da177e4 LT |
847 | return 0; |
848 | ||
849 | fail: | |
5c8cafd6 | 850 | for (j = 0; j < i; j++) |
1ed8516f | 851 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
98c6d1b2 | 852 | kfree(net->ipv6.icmp_sk); |
1da177e4 LT |
853 | return err; |
854 | } | |
855 | ||
98c6d1b2 | 856 | static void __net_exit icmpv6_sk_exit(struct net *net) |
1da177e4 LT |
857 | { |
858 | int i; | |
859 | ||
6f912042 | 860 | for_each_possible_cpu(i) { |
1ed8516f | 861 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
1da177e4 | 862 | } |
98c6d1b2 DL |
863 | kfree(net->ipv6.icmp_sk); |
864 | } | |
865 | ||
8ed7edce | 866 | static struct pernet_operations icmpv6_sk_ops = { |
98c6d1b2 DL |
867 | .init = icmpv6_sk_init, |
868 | .exit = icmpv6_sk_exit, | |
869 | }; | |
870 | ||
871 | int __init icmpv6_init(void) | |
872 | { | |
873 | int err; | |
874 | ||
875 | err = register_pernet_subsys(&icmpv6_sk_ops); | |
876 | if (err < 0) | |
877 | return err; | |
878 | ||
879 | err = -EAGAIN; | |
880 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) | |
881 | goto fail; | |
882 | return 0; | |
883 | ||
884 | fail: | |
885 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
886 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
887 | return err; | |
888 | } | |
889 | ||
8ed7edce | 890 | void icmpv6_cleanup(void) |
98c6d1b2 DL |
891 | { |
892 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
1da177e4 LT |
893 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
894 | } | |
895 | ||
98c6d1b2 | 896 | |
9b5b5cff | 897 | static const struct icmp6_err { |
1da177e4 LT |
898 | int err; |
899 | int fatal; | |
900 | } tab_unreach[] = { | |
901 | { /* NOROUTE */ | |
902 | .err = ENETUNREACH, | |
903 | .fatal = 0, | |
904 | }, | |
905 | { /* ADM_PROHIBITED */ | |
906 | .err = EACCES, | |
907 | .fatal = 1, | |
908 | }, | |
909 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
910 | .err = EHOSTUNREACH, | |
911 | .fatal = 0, | |
912 | }, | |
913 | { /* ADDR_UNREACH */ | |
914 | .err = EHOSTUNREACH, | |
915 | .fatal = 0, | |
916 | }, | |
917 | { /* PORT_UNREACH */ | |
918 | .err = ECONNREFUSED, | |
919 | .fatal = 1, | |
920 | }, | |
921 | }; | |
922 | ||
d5fdd6ba | 923 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
1da177e4 LT |
924 | { |
925 | int fatal = 0; | |
926 | ||
927 | *err = EPROTO; | |
928 | ||
929 | switch (type) { | |
930 | case ICMPV6_DEST_UNREACH: | |
931 | fatal = 1; | |
932 | if (code <= ICMPV6_PORT_UNREACH) { | |
933 | *err = tab_unreach[code].err; | |
934 | fatal = tab_unreach[code].fatal; | |
935 | } | |
936 | break; | |
937 | ||
938 | case ICMPV6_PKT_TOOBIG: | |
939 | *err = EMSGSIZE; | |
940 | break; | |
1ab1457c | 941 | |
1da177e4 LT |
942 | case ICMPV6_PARAMPROB: |
943 | *err = EPROTO; | |
944 | fatal = 1; | |
945 | break; | |
946 | ||
947 | case ICMPV6_TIME_EXCEED: | |
948 | *err = EHOSTUNREACH; | |
949 | break; | |
3ff50b79 | 950 | } |
1da177e4 LT |
951 | |
952 | return fatal; | |
953 | } | |
954 | ||
7159039a YH |
955 | EXPORT_SYMBOL(icmpv6_err_convert); |
956 | ||
1da177e4 | 957 | #ifdef CONFIG_SYSCTL |
760f2d01 | 958 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 | 959 | { |
1da177e4 | 960 | .procname = "ratelimit", |
41a76906 | 961 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
962 | .maxlen = sizeof(int), |
963 | .mode = 0644, | |
6d9f239a | 964 | .proc_handler = proc_dointvec_ms_jiffies, |
1da177e4 | 965 | }, |
f8572d8f | 966 | { }, |
1da177e4 | 967 | }; |
760f2d01 | 968 | |
2c8c1e72 | 969 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
760f2d01 DL |
970 | { |
971 | struct ctl_table *table; | |
972 | ||
973 | table = kmemdup(ipv6_icmp_table_template, | |
974 | sizeof(ipv6_icmp_table_template), | |
975 | GFP_KERNEL); | |
5ee09105 YH |
976 | |
977 | if (table) | |
978 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
979 | ||
760f2d01 DL |
980 | return table; |
981 | } | |
1da177e4 LT |
982 | #endif |
983 |