Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Internet Control Message Protocol (ICMPv6) | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * | |
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, | |
1d28f42c | 238 | len, fl->flowi_proto, |
1da177e4 LT |
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, | |
1d28f42c | 251 | len, fl->flowi_proto, |
868c86bc | 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 | ||
452edd59 DM |
327 | dst = xfrm_lookup(net, dst, fl, sk, 0); |
328 | if (!IS_ERR(dst)) { | |
b42835db DM |
329 | if (dst != dst2) |
330 | return dst; | |
452edd59 DM |
331 | } else { |
332 | if (PTR_ERR(dst) == -EPERM) | |
333 | dst = NULL; | |
334 | else | |
335 | return dst; | |
b42835db DM |
336 | } |
337 | ||
338 | err = xfrm_decode_session_reverse(skb, &fl2, AF_INET6); | |
339 | if (err) | |
340 | goto relookup_failed; | |
341 | ||
342 | err = ip6_dst_lookup(sk, &dst2, &fl2); | |
343 | if (err) | |
344 | goto relookup_failed; | |
345 | ||
452edd59 DM |
346 | dst2 = xfrm_lookup(net, dst2, &fl2, sk, XFRM_LOOKUP_ICMP); |
347 | if (!IS_ERR(dst2)) { | |
b42835db DM |
348 | dst_release(dst); |
349 | dst = dst2; | |
452edd59 DM |
350 | } else { |
351 | err = PTR_ERR(dst2); | |
352 | if (err == -EPERM) { | |
353 | dst_release(dst); | |
354 | return dst2; | |
355 | } else | |
356 | goto relookup_failed; | |
b42835db DM |
357 | } |
358 | ||
359 | relookup_failed: | |
360 | if (dst) | |
361 | return dst; | |
362 | return ERR_PTR(err); | |
363 | } | |
364 | ||
1da177e4 LT |
365 | /* |
366 | * Send an ICMP message in response to a packet in error | |
367 | */ | |
3ffe533c | 368 | void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) |
1da177e4 | 369 | { |
c346dca1 | 370 | struct net *net = dev_net(skb->dev); |
1da177e4 | 371 | struct inet6_dev *idev = NULL; |
0660e03f | 372 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
84427d53 YH |
373 | struct sock *sk; |
374 | struct ipv6_pinfo *np; | |
1da177e4 LT |
375 | struct in6_addr *saddr = NULL; |
376 | struct dst_entry *dst; | |
377 | struct icmp6hdr tmp_hdr; | |
378 | struct flowi fl; | |
379 | struct icmpv6_msg msg; | |
380 | int iif = 0; | |
381 | int addr_type = 0; | |
382 | int len; | |
e651f03a | 383 | int hlimit; |
1da177e4 LT |
384 | int err = 0; |
385 | ||
27a884dc ACM |
386 | if ((u8 *)hdr < skb->head || |
387 | (skb->network_header + sizeof(*hdr)) > skb->tail) | |
1da177e4 LT |
388 | return; |
389 | ||
390 | /* | |
1ab1457c | 391 | * Make sure we respect the rules |
1da177e4 LT |
392 | * i.e. RFC 1885 2.4(e) |
393 | * Rule (e.1) is enforced by not using icmpv6_send | |
394 | * in any code that processes icmp errors. | |
395 | */ | |
396 | addr_type = ipv6_addr_type(&hdr->daddr); | |
397 | ||
9a43b709 | 398 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
1da177e4 LT |
399 | saddr = &hdr->daddr; |
400 | ||
401 | /* | |
402 | * Dest addr check | |
403 | */ | |
404 | ||
405 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
406 | if (type != ICMPV6_PKT_TOOBIG && | |
1ab1457c YH |
407 | !(type == ICMPV6_PARAMPROB && |
408 | code == ICMPV6_UNK_OPTION && | |
1da177e4 LT |
409 | (opt_unrec(skb, info)))) |
410 | return; | |
411 | ||
412 | saddr = NULL; | |
413 | } | |
414 | ||
415 | addr_type = ipv6_addr_type(&hdr->saddr); | |
416 | ||
417 | /* | |
418 | * Source addr check | |
419 | */ | |
420 | ||
421 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
422 | iif = skb->dev->ifindex; | |
423 | ||
424 | /* | |
8de3351e YH |
425 | * Must not send error if the source does not uniquely |
426 | * identify a single node (RFC2463 Section 2.4). | |
427 | * We check unspecified / multicast addresses here, | |
428 | * and anycast addresses will be checked later. | |
1da177e4 LT |
429 | */ |
430 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 431 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
432 | return; |
433 | } | |
434 | ||
1ab1457c | 435 | /* |
1da177e4 LT |
436 | * Never answer to a ICMP packet. |
437 | */ | |
438 | if (is_ineligible(skb)) { | |
64ce2073 | 439 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
440 | return; |
441 | } | |
442 | ||
79383236 MN |
443 | mip6_addr_swap(skb); |
444 | ||
1da177e4 | 445 | memset(&fl, 0, sizeof(fl)); |
1d28f42c | 446 | fl.flowi_proto = IPPROTO_ICMPV6; |
1da177e4 LT |
447 | ipv6_addr_copy(&fl.fl6_dst, &hdr->saddr); |
448 | if (saddr) | |
449 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
1d28f42c | 450 | fl.flowi_oif = iif; |
6281dcc9 DM |
451 | fl.fl6_icmp_type = type; |
452 | fl.fl6_icmp_code = code; | |
beb8d13b | 453 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 454 | |
fdc0bde9 DL |
455 | sk = icmpv6_xmit_lock(net); |
456 | if (sk == NULL) | |
405666db | 457 | return; |
fdc0bde9 | 458 | np = inet6_sk(sk); |
405666db | 459 | |
1da177e4 LT |
460 | if (!icmpv6_xrlim_allow(sk, type, &fl)) |
461 | goto out; | |
462 | ||
463 | tmp_hdr.icmp6_type = type; | |
464 | tmp_hdr.icmp6_code = code; | |
465 | tmp_hdr.icmp6_cksum = 0; | |
466 | tmp_hdr.icmp6_pointer = htonl(info); | |
467 | ||
1d28f42c DM |
468 | if (!fl.flowi_oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
469 | fl.flowi_oif = np->mcast_oif; | |
1da177e4 | 470 | |
b42835db DM |
471 | dst = icmpv6_route_lookup(net, skb, sk, &fl); |
472 | if (IS_ERR(dst)) | |
1da177e4 | 473 | goto out; |
8de3351e | 474 | |
1da177e4 LT |
475 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) |
476 | hlimit = np->mcast_hops; | |
477 | else | |
478 | hlimit = np->hop_limit; | |
479 | if (hlimit < 0) | |
6b75d090 | 480 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
481 | |
482 | msg.skb = skb; | |
bbe735e4 | 483 | msg.offset = skb_network_offset(skb); |
763ecff1 | 484 | msg.type = type; |
1da177e4 LT |
485 | |
486 | len = skb->len - msg.offset; | |
487 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
488 | if (len < 0) { | |
64ce2073 | 489 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
490 | goto out_dst_release; |
491 | } | |
492 | ||
493 | idev = in6_dev_get(skb->dev); | |
494 | ||
495 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
496 | len + sizeof(struct icmp6hdr), | |
e651f03a GR |
497 | sizeof(struct icmp6hdr), hlimit, |
498 | np->tclass, NULL, &fl, (struct rt6_info*)dst, | |
13b52cd4 | 499 | MSG_DONTWAIT, np->dontfrag); |
1da177e4 | 500 | if (err) { |
00d9d6a1 | 501 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 LT |
502 | ip6_flush_pending_frames(sk); |
503 | goto out_put; | |
504 | } | |
505 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, len + sizeof(struct icmp6hdr)); | |
506 | ||
1da177e4 LT |
507 | out_put: |
508 | if (likely(idev != NULL)) | |
509 | in6_dev_put(idev); | |
510 | out_dst_release: | |
511 | dst_release(dst); | |
512 | out: | |
405666db | 513 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
514 | } |
515 | ||
7159039a YH |
516 | EXPORT_SYMBOL(icmpv6_send); |
517 | ||
1da177e4 LT |
518 | static void icmpv6_echo_reply(struct sk_buff *skb) |
519 | { | |
c346dca1 | 520 | struct net *net = dev_net(skb->dev); |
84427d53 | 521 | struct sock *sk; |
1da177e4 | 522 | struct inet6_dev *idev; |
84427d53 | 523 | struct ipv6_pinfo *np; |
1da177e4 | 524 | struct in6_addr *saddr = NULL; |
cc70ab26 | 525 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 LT |
526 | struct icmp6hdr tmp_hdr; |
527 | struct flowi fl; | |
528 | struct icmpv6_msg msg; | |
529 | struct dst_entry *dst; | |
530 | int err = 0; | |
531 | int hlimit; | |
532 | ||
0660e03f | 533 | saddr = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
534 | |
535 | if (!ipv6_unicast_destination(skb)) | |
536 | saddr = NULL; | |
537 | ||
538 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
539 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
540 | ||
541 | memset(&fl, 0, sizeof(fl)); | |
1d28f42c | 542 | fl.flowi_proto = IPPROTO_ICMPV6; |
0660e03f | 543 | ipv6_addr_copy(&fl.fl6_dst, &ipv6_hdr(skb)->saddr); |
1da177e4 LT |
544 | if (saddr) |
545 | ipv6_addr_copy(&fl.fl6_src, saddr); | |
1d28f42c | 546 | fl.flowi_oif = skb->dev->ifindex; |
6281dcc9 | 547 | fl.fl6_icmp_type = ICMPV6_ECHO_REPLY; |
beb8d13b | 548 | security_skb_classify_flow(skb, &fl); |
1da177e4 | 549 | |
fdc0bde9 DL |
550 | sk = icmpv6_xmit_lock(net); |
551 | if (sk == NULL) | |
405666db | 552 | return; |
fdc0bde9 | 553 | np = inet6_sk(sk); |
405666db | 554 | |
1d28f42c DM |
555 | if (!fl.flowi_oif && ipv6_addr_is_multicast(&fl.fl6_dst)) |
556 | fl.flowi_oif = np->mcast_oif; | |
1da177e4 LT |
557 | |
558 | err = ip6_dst_lookup(sk, &dst, &fl); | |
559 | if (err) | |
560 | goto out; | |
452edd59 DM |
561 | dst = xfrm_lookup(net, dst, &fl, sk, 0); |
562 | if (IS_ERR(dst)) | |
e104411b | 563 | goto out; |
1da177e4 LT |
564 | |
565 | if (ipv6_addr_is_multicast(&fl.fl6_dst)) | |
566 | hlimit = np->mcast_hops; | |
567 | else | |
568 | hlimit = np->hop_limit; | |
569 | if (hlimit < 0) | |
6b75d090 | 570 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
571 | |
572 | idev = in6_dev_get(skb->dev); | |
573 | ||
574 | msg.skb = skb; | |
575 | msg.offset = 0; | |
763ecff1 | 576 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
577 | |
578 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
e651f03a | 579 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl, |
13b52cd4 BH |
580 | (struct rt6_info*)dst, MSG_DONTWAIT, |
581 | np->dontfrag); | |
1da177e4 LT |
582 | |
583 | if (err) { | |
00d9d6a1 | 584 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 LT |
585 | ip6_flush_pending_frames(sk); |
586 | goto out_put; | |
587 | } | |
588 | err = icmpv6_push_pending_frames(sk, &fl, &tmp_hdr, skb->len + sizeof(struct icmp6hdr)); | |
589 | ||
1ab1457c | 590 | out_put: |
1da177e4 LT |
591 | if (likely(idev != NULL)) |
592 | in6_dev_put(idev); | |
1da177e4 | 593 | dst_release(dst); |
1ab1457c | 594 | out: |
405666db | 595 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
596 | } |
597 | ||
d5fdd6ba | 598 | static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
1da177e4 | 599 | { |
41135cc8 | 600 | const struct inet6_protocol *ipprot; |
1da177e4 LT |
601 | int inner_offset; |
602 | int hash; | |
603 | u8 nexthdr; | |
604 | ||
605 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
606 | return; | |
607 | ||
608 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
609 | if (ipv6_ext_hdr(nexthdr)) { | |
610 | /* now skip over extension headers */ | |
0d3d077c | 611 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr); |
1da177e4 LT |
612 | if (inner_offset<0) |
613 | return; | |
614 | } else { | |
615 | inner_offset = sizeof(struct ipv6hdr); | |
616 | } | |
617 | ||
618 | /* Checkin header including 8 bytes of inner protocol header. */ | |
619 | if (!pskb_may_pull(skb, inner_offset+8)) | |
620 | return; | |
621 | ||
1da177e4 LT |
622 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
623 | Without this we will not able f.e. to make source routed | |
624 | pmtu discovery. | |
625 | Corresponding argument (opt) to notifiers is already added. | |
626 | --ANK (980726) | |
627 | */ | |
628 | ||
629 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
630 | ||
631 | rcu_read_lock(); | |
632 | ipprot = rcu_dereference(inet6_protos[hash]); | |
633 | if (ipprot && ipprot->err_handler) | |
634 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
635 | rcu_read_unlock(); | |
636 | ||
69d6da0b | 637 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 638 | } |
1ab1457c | 639 | |
1da177e4 LT |
640 | /* |
641 | * Handle icmp messages | |
642 | */ | |
643 | ||
e5bbef20 | 644 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 645 | { |
1da177e4 LT |
646 | struct net_device *dev = skb->dev; |
647 | struct inet6_dev *idev = __in6_dev_get(dev); | |
648 | struct in6_addr *saddr, *daddr; | |
649 | struct ipv6hdr *orig_hdr; | |
650 | struct icmp6hdr *hdr; | |
d5fdd6ba | 651 | u8 type; |
1da177e4 | 652 | |
aebcf82c | 653 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 654 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
655 | int nh; |
656 | ||
def8b4fa | 657 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
658 | XFRM_STATE_ICMP)) |
659 | goto drop_no_count; | |
660 | ||
8b7817f3 HX |
661 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
662 | goto drop_no_count; | |
663 | ||
664 | nh = skb_network_offset(skb); | |
665 | skb_set_network_header(skb, sizeof(*hdr)); | |
666 | ||
667 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
668 | goto drop_no_count; | |
669 | ||
670 | skb_set_network_header(skb, nh); | |
671 | } | |
672 | ||
e41b5368 | 673 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
1da177e4 | 674 | |
0660e03f ACM |
675 | saddr = &ipv6_hdr(skb)->saddr; |
676 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
677 | |
678 | /* Perform checksum. */ | |
fb286bb2 | 679 | switch (skb->ip_summed) { |
84fa7933 | 680 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
681 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
682 | skb->csum)) | |
683 | break; | |
684 | /* fall through */ | |
685 | case CHECKSUM_NONE: | |
868c86bc AV |
686 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
687 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 688 | if (__skb_checksum_complete(skb)) { |
5b095d98 | 689 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", |
0c6ce78a | 690 | saddr, daddr); |
1da177e4 LT |
691 | goto discard_it; |
692 | } | |
693 | } | |
694 | ||
8cf22943 HX |
695 | if (!pskb_pull(skb, sizeof(*hdr))) |
696 | goto discard_it; | |
1da177e4 | 697 | |
cc70ab26 | 698 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
699 | |
700 | type = hdr->icmp6_type; | |
701 | ||
55d43808 | 702 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
1da177e4 LT |
703 | |
704 | switch (type) { | |
705 | case ICMPV6_ECHO_REQUEST: | |
706 | icmpv6_echo_reply(skb); | |
707 | break; | |
708 | ||
709 | case ICMPV6_ECHO_REPLY: | |
710 | /* we couldn't care less */ | |
711 | break; | |
712 | ||
713 | case ICMPV6_PKT_TOOBIG: | |
714 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
715 | standard destination cache. Seems, only "advanced" | |
716 | destination cache will allow to solve this problem | |
717 | --ANK (980726) | |
718 | */ | |
719 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
720 | goto discard_it; | |
cc70ab26 | 721 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
722 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
723 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
724 | ntohl(hdr->icmp6_mtu)); | |
725 | ||
726 | /* | |
727 | * Drop through to notify | |
728 | */ | |
729 | ||
730 | case ICMPV6_DEST_UNREACH: | |
731 | case ICMPV6_TIME_EXCEED: | |
732 | case ICMPV6_PARAMPROB: | |
733 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
734 | break; | |
735 | ||
736 | case NDISC_ROUTER_SOLICITATION: | |
737 | case NDISC_ROUTER_ADVERTISEMENT: | |
738 | case NDISC_NEIGHBOUR_SOLICITATION: | |
739 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
740 | case NDISC_REDIRECT: | |
741 | ndisc_rcv(skb); | |
742 | break; | |
743 | ||
744 | case ICMPV6_MGM_QUERY: | |
745 | igmp6_event_query(skb); | |
746 | break; | |
747 | ||
748 | case ICMPV6_MGM_REPORT: | |
749 | igmp6_event_report(skb); | |
750 | break; | |
751 | ||
752 | case ICMPV6_MGM_REDUCTION: | |
753 | case ICMPV6_NI_QUERY: | |
754 | case ICMPV6_NI_REPLY: | |
755 | case ICMPV6_MLD2_REPORT: | |
756 | case ICMPV6_DHAAD_REQUEST: | |
757 | case ICMPV6_DHAAD_REPLY: | |
758 | case ICMPV6_MOBILE_PREFIX_SOL: | |
759 | case ICMPV6_MOBILE_PREFIX_ADV: | |
760 | break; | |
761 | ||
762 | default: | |
64ce2073 | 763 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
764 | |
765 | /* informational */ | |
766 | if (type & ICMPV6_INFOMSG_MASK) | |
767 | break; | |
768 | ||
1ab1457c YH |
769 | /* |
770 | * error of unknown type. | |
771 | * must pass to upper level | |
1da177e4 LT |
772 | */ |
773 | ||
774 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
775 | } |
776 | ||
1da177e4 LT |
777 | kfree_skb(skb); |
778 | return 0; | |
779 | ||
780 | discard_it: | |
e41b5368 | 781 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
8b7817f3 | 782 | drop_no_count: |
1da177e4 LT |
783 | kfree_skb(skb); |
784 | return 0; | |
785 | } | |
786 | ||
95e41e93 YH |
787 | void icmpv6_flow_init(struct sock *sk, struct flowi *fl, |
788 | u8 type, | |
789 | const struct in6_addr *saddr, | |
790 | const struct in6_addr *daddr, | |
791 | int oif) | |
792 | { | |
793 | memset(fl, 0, sizeof(*fl)); | |
794 | ipv6_addr_copy(&fl->fl6_src, saddr); | |
795 | ipv6_addr_copy(&fl->fl6_dst, daddr); | |
1d28f42c | 796 | fl->flowi_proto = IPPROTO_ICMPV6; |
6281dcc9 DM |
797 | fl->fl6_icmp_type = type; |
798 | fl->fl6_icmp_code = 0; | |
1d28f42c | 799 | fl->flowi_oif = oif; |
95e41e93 YH |
800 | security_sk_classify_flow(sk, fl); |
801 | } | |
802 | ||
640c41c7 | 803 | /* |
b7e729c4 | 804 | * Special lock-class for __icmpv6_sk: |
640c41c7 IM |
805 | */ |
806 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
807 | ||
98c6d1b2 | 808 | static int __net_init icmpv6_sk_init(struct net *net) |
1da177e4 LT |
809 | { |
810 | struct sock *sk; | |
811 | int err, i, j; | |
812 | ||
98c6d1b2 DL |
813 | net->ipv6.icmp_sk = |
814 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
815 | if (net->ipv6.icmp_sk == NULL) | |
79c91159 DL |
816 | return -ENOMEM; |
817 | ||
6f912042 | 818 | for_each_possible_cpu(i) { |
1ed8516f DL |
819 | err = inet_ctl_sock_create(&sk, PF_INET6, |
820 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
1da177e4 LT |
821 | if (err < 0) { |
822 | printk(KERN_ERR | |
823 | "Failed to initialize the ICMP6 control socket " | |
824 | "(err %d).\n", | |
825 | err); | |
826 | goto fail; | |
827 | } | |
828 | ||
1ed8516f | 829 | net->ipv6.icmp_sk[i] = sk; |
5c8cafd6 | 830 | |
640c41c7 IM |
831 | /* |
832 | * Split off their lock-class, because sk->sk_dst_lock | |
833 | * gets used from softirqs, which is safe for | |
b7e729c4 | 834 | * __icmpv6_sk (because those never get directly used |
640c41c7 IM |
835 | * via userspace syscalls), but unsafe for normal sockets. |
836 | */ | |
837 | lockdep_set_class(&sk->sk_dst_lock, | |
838 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
839 | |
840 | /* Enough space for 2 64K ICMP packets, including | |
841 | * sk_buff struct overhead. | |
842 | */ | |
843 | sk->sk_sndbuf = | |
844 | (2 * ((64 * 1024) + sizeof(struct sk_buff))); | |
1da177e4 | 845 | } |
1da177e4 LT |
846 | return 0; |
847 | ||
848 | fail: | |
5c8cafd6 | 849 | for (j = 0; j < i; j++) |
1ed8516f | 850 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
98c6d1b2 | 851 | kfree(net->ipv6.icmp_sk); |
1da177e4 LT |
852 | return err; |
853 | } | |
854 | ||
98c6d1b2 | 855 | static void __net_exit icmpv6_sk_exit(struct net *net) |
1da177e4 LT |
856 | { |
857 | int i; | |
858 | ||
6f912042 | 859 | for_each_possible_cpu(i) { |
1ed8516f | 860 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
1da177e4 | 861 | } |
98c6d1b2 DL |
862 | kfree(net->ipv6.icmp_sk); |
863 | } | |
864 | ||
8ed7edce | 865 | static struct pernet_operations icmpv6_sk_ops = { |
98c6d1b2 DL |
866 | .init = icmpv6_sk_init, |
867 | .exit = icmpv6_sk_exit, | |
868 | }; | |
869 | ||
870 | int __init icmpv6_init(void) | |
871 | { | |
872 | int err; | |
873 | ||
874 | err = register_pernet_subsys(&icmpv6_sk_ops); | |
875 | if (err < 0) | |
876 | return err; | |
877 | ||
878 | err = -EAGAIN; | |
879 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) | |
880 | goto fail; | |
881 | return 0; | |
882 | ||
883 | fail: | |
884 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
885 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
886 | return err; | |
887 | } | |
888 | ||
8ed7edce | 889 | void icmpv6_cleanup(void) |
98c6d1b2 DL |
890 | { |
891 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
1da177e4 LT |
892 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
893 | } | |
894 | ||
98c6d1b2 | 895 | |
9b5b5cff | 896 | static const struct icmp6_err { |
1da177e4 LT |
897 | int err; |
898 | int fatal; | |
899 | } tab_unreach[] = { | |
900 | { /* NOROUTE */ | |
901 | .err = ENETUNREACH, | |
902 | .fatal = 0, | |
903 | }, | |
904 | { /* ADM_PROHIBITED */ | |
905 | .err = EACCES, | |
906 | .fatal = 1, | |
907 | }, | |
908 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
909 | .err = EHOSTUNREACH, | |
910 | .fatal = 0, | |
911 | }, | |
912 | { /* ADDR_UNREACH */ | |
913 | .err = EHOSTUNREACH, | |
914 | .fatal = 0, | |
915 | }, | |
916 | { /* PORT_UNREACH */ | |
917 | .err = ECONNREFUSED, | |
918 | .fatal = 1, | |
919 | }, | |
920 | }; | |
921 | ||
d5fdd6ba | 922 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
1da177e4 LT |
923 | { |
924 | int fatal = 0; | |
925 | ||
926 | *err = EPROTO; | |
927 | ||
928 | switch (type) { | |
929 | case ICMPV6_DEST_UNREACH: | |
930 | fatal = 1; | |
931 | if (code <= ICMPV6_PORT_UNREACH) { | |
932 | *err = tab_unreach[code].err; | |
933 | fatal = tab_unreach[code].fatal; | |
934 | } | |
935 | break; | |
936 | ||
937 | case ICMPV6_PKT_TOOBIG: | |
938 | *err = EMSGSIZE; | |
939 | break; | |
1ab1457c | 940 | |
1da177e4 LT |
941 | case ICMPV6_PARAMPROB: |
942 | *err = EPROTO; | |
943 | fatal = 1; | |
944 | break; | |
945 | ||
946 | case ICMPV6_TIME_EXCEED: | |
947 | *err = EHOSTUNREACH; | |
948 | break; | |
3ff50b79 | 949 | } |
1da177e4 LT |
950 | |
951 | return fatal; | |
952 | } | |
953 | ||
7159039a YH |
954 | EXPORT_SYMBOL(icmpv6_err_convert); |
955 | ||
1da177e4 | 956 | #ifdef CONFIG_SYSCTL |
760f2d01 | 957 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 | 958 | { |
1da177e4 | 959 | .procname = "ratelimit", |
41a76906 | 960 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
961 | .maxlen = sizeof(int), |
962 | .mode = 0644, | |
6d9f239a | 963 | .proc_handler = proc_dointvec_ms_jiffies, |
1da177e4 | 964 | }, |
f8572d8f | 965 | { }, |
1da177e4 | 966 | }; |
760f2d01 | 967 | |
2c8c1e72 | 968 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
760f2d01 DL |
969 | { |
970 | struct ctl_table *table; | |
971 | ||
972 | table = kmemdup(ipv6_icmp_table_template, | |
973 | sizeof(ipv6_icmp_table_template), | |
974 | GFP_KERNEL); | |
5ee09105 YH |
975 | |
976 | if (table) | |
977 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
978 | ||
760f2d01 DL |
979 | return table; |
980 | } | |
1da177e4 LT |
981 | #endif |
982 |