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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Internet Control Message Protocol (ICMPv6) | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * | |
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; |
75f2811c | 138 | __be16 frag_off; |
1da177e4 LT |
139 | |
140 | if (len < 0) | |
141 | return 1; | |
142 | ||
75f2811c | 143 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); |
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 | 160 | */ |
92d86829 | 161 | static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
4c9483b2 | 162 | struct flowi6 *fl6) |
1da177e4 LT |
163 | { |
164 | struct dst_entry *dst; | |
3b1e0a65 | 165 | struct net *net = sock_net(sk); |
92d86829 | 166 | bool res = false; |
1da177e4 LT |
167 | |
168 | /* Informational messages are not limited. */ | |
169 | if (type & ICMPV6_INFOMSG_MASK) | |
92d86829 | 170 | return true; |
1da177e4 LT |
171 | |
172 | /* Do not limit pmtu discovery, it would break it. */ | |
173 | if (type == ICMPV6_PKT_TOOBIG) | |
92d86829 | 174 | return true; |
1da177e4 | 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 | */ | |
4c9483b2 | 181 | dst = ip6_route_output(net, sk, fl6); |
1da177e4 | 182 | if (dst->error) { |
3bd653c8 | 183 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
a11d206d | 184 | IPSTATS_MIB_OUTNOROUTES); |
1da177e4 | 185 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
92d86829 | 186 | res = true; |
1da177e4 LT |
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 | ||
92d86829 DM |
195 | if (!rt->rt6i_peer) |
196 | rt6_bind_peer(rt, 1); | |
197 | res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo); | |
1da177e4 LT |
198 | } |
199 | dst_release(dst); | |
200 | return res; | |
201 | } | |
202 | ||
203 | /* | |
204 | * an inline helper for the "simple" if statement below | |
205 | * checks if parameter problem report is caused by an | |
1ab1457c | 206 | * unrecognized IPv6 option that has the Option Type |
1da177e4 LT |
207 | * highest-order two bits set to 10 |
208 | */ | |
209 | ||
210 | static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset) | |
211 | { | |
212 | u8 _optval, *op; | |
213 | ||
bbe735e4 | 214 | offset += skb_network_offset(skb); |
1da177e4 LT |
215 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
216 | if (op == NULL) | |
217 | return 1; | |
218 | return (*op & 0xC0) == 0x80; | |
219 | } | |
220 | ||
4c9483b2 | 221 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len) |
1da177e4 LT |
222 | { |
223 | struct sk_buff *skb; | |
224 | struct icmp6hdr *icmp6h; | |
225 | int err = 0; | |
226 | ||
227 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
228 | goto out; | |
229 | ||
cc70ab26 | 230 | icmp6h = icmp6_hdr(skb); |
1da177e4 LT |
231 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
232 | icmp6h->icmp6_cksum = 0; | |
233 | ||
234 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
07f0757a | 235 | skb->csum = csum_partial(icmp6h, |
1da177e4 | 236 | sizeof(struct icmp6hdr), skb->csum); |
4c9483b2 DM |
237 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
238 | &fl6->daddr, | |
239 | len, fl6->flowi6_proto, | |
1da177e4 LT |
240 | skb->csum); |
241 | } else { | |
868c86bc | 242 | __wsum tmp_csum = 0; |
1da177e4 LT |
243 | |
244 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
245 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
246 | } | |
247 | ||
07f0757a | 248 | tmp_csum = csum_partial(icmp6h, |
1da177e4 | 249 | sizeof(struct icmp6hdr), tmp_csum); |
4c9483b2 DM |
250 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
251 | &fl6->daddr, | |
252 | len, fl6->flowi6_proto, | |
868c86bc | 253 | tmp_csum); |
1da177e4 | 254 | } |
1da177e4 LT |
255 | ip6_push_pending_frames(sk); |
256 | out: | |
257 | return err; | |
258 | } | |
259 | ||
260 | struct icmpv6_msg { | |
261 | struct sk_buff *skb; | |
262 | int offset; | |
763ecff1 | 263 | uint8_t type; |
1da177e4 LT |
264 | }; |
265 | ||
266 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
267 | { | |
268 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
269 | struct sk_buff *org_skb = msg->skb; | |
5f92a738 | 270 | __wsum csum = 0; |
1da177e4 LT |
271 | |
272 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
273 | to, len, csum); | |
274 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
763ecff1 YK |
275 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
276 | nf_ct_attach(skb, org_skb); | |
1da177e4 LT |
277 | return 0; |
278 | } | |
279 | ||
59fbb3a6 | 280 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
79383236 MN |
281 | static void mip6_addr_swap(struct sk_buff *skb) |
282 | { | |
0660e03f | 283 | struct ipv6hdr *iph = ipv6_hdr(skb); |
79383236 MN |
284 | struct inet6_skb_parm *opt = IP6CB(skb); |
285 | struct ipv6_destopt_hao *hao; | |
286 | struct in6_addr tmp; | |
287 | int off; | |
288 | ||
289 | if (opt->dsthao) { | |
290 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
291 | if (likely(off >= 0)) { | |
d56f90a7 ACM |
292 | hao = (struct ipv6_destopt_hao *) |
293 | (skb_network_header(skb) + off); | |
4e3fd7a0 AD |
294 | tmp = iph->saddr; |
295 | iph->saddr = hao->addr; | |
296 | hao->addr = tmp; | |
79383236 MN |
297 | } |
298 | } | |
299 | } | |
300 | #else | |
301 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
302 | #endif | |
303 | ||
b42835db | 304 | static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb, |
4c9483b2 | 305 | struct sock *sk, struct flowi6 *fl6) |
b42835db DM |
306 | { |
307 | struct dst_entry *dst, *dst2; | |
4c9483b2 | 308 | struct flowi6 fl2; |
b42835db DM |
309 | int err; |
310 | ||
4c9483b2 | 311 | err = ip6_dst_lookup(sk, &dst, fl6); |
b42835db DM |
312 | if (err) |
313 | return ERR_PTR(err); | |
314 | ||
315 | /* | |
316 | * We won't send icmp if the destination is known | |
317 | * anycast. | |
318 | */ | |
319 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
320 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
321 | dst_release(dst); | |
322 | return ERR_PTR(-EINVAL); | |
323 | } | |
324 | ||
325 | /* No need to clone since we're just using its address. */ | |
326 | dst2 = dst; | |
327 | ||
4c9483b2 | 328 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); |
452edd59 | 329 | if (!IS_ERR(dst)) { |
b42835db DM |
330 | if (dst != dst2) |
331 | return dst; | |
452edd59 DM |
332 | } else { |
333 | if (PTR_ERR(dst) == -EPERM) | |
334 | dst = NULL; | |
335 | else | |
336 | return dst; | |
b42835db DM |
337 | } |
338 | ||
4c9483b2 | 339 | err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); |
b42835db DM |
340 | if (err) |
341 | goto relookup_failed; | |
342 | ||
343 | err = ip6_dst_lookup(sk, &dst2, &fl2); | |
344 | if (err) | |
345 | goto relookup_failed; | |
346 | ||
4c9483b2 | 347 | dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); |
452edd59 | 348 | if (!IS_ERR(dst2)) { |
b42835db DM |
349 | dst_release(dst); |
350 | dst = dst2; | |
452edd59 DM |
351 | } else { |
352 | err = PTR_ERR(dst2); | |
353 | if (err == -EPERM) { | |
354 | dst_release(dst); | |
355 | return dst2; | |
356 | } else | |
357 | goto relookup_failed; | |
b42835db DM |
358 | } |
359 | ||
360 | relookup_failed: | |
361 | if (dst) | |
362 | return dst; | |
363 | return ERR_PTR(err); | |
364 | } | |
365 | ||
1da177e4 LT |
366 | /* |
367 | * Send an ICMP message in response to a packet in error | |
368 | */ | |
3ffe533c | 369 | void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info) |
1da177e4 | 370 | { |
c346dca1 | 371 | struct net *net = dev_net(skb->dev); |
1da177e4 | 372 | struct inet6_dev *idev = NULL; |
0660e03f | 373 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
84427d53 YH |
374 | struct sock *sk; |
375 | struct ipv6_pinfo *np; | |
b71d1d42 | 376 | const struct in6_addr *saddr = NULL; |
1da177e4 LT |
377 | struct dst_entry *dst; |
378 | struct icmp6hdr tmp_hdr; | |
4c9483b2 | 379 | struct flowi6 fl6; |
1da177e4 LT |
380 | struct icmpv6_msg msg; |
381 | int iif = 0; | |
382 | int addr_type = 0; | |
383 | int len; | |
e651f03a | 384 | int hlimit; |
1da177e4 LT |
385 | int err = 0; |
386 | ||
27a884dc ACM |
387 | if ((u8 *)hdr < skb->head || |
388 | (skb->network_header + sizeof(*hdr)) > skb->tail) | |
1da177e4 LT |
389 | return; |
390 | ||
391 | /* | |
1ab1457c | 392 | * Make sure we respect the rules |
1da177e4 LT |
393 | * i.e. RFC 1885 2.4(e) |
394 | * Rule (e.1) is enforced by not using icmpv6_send | |
395 | * in any code that processes icmp errors. | |
396 | */ | |
397 | addr_type = ipv6_addr_type(&hdr->daddr); | |
398 | ||
9a43b709 | 399 | if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0)) |
1da177e4 LT |
400 | saddr = &hdr->daddr; |
401 | ||
402 | /* | |
403 | * Dest addr check | |
404 | */ | |
405 | ||
406 | if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST)) { | |
407 | if (type != ICMPV6_PKT_TOOBIG && | |
1ab1457c YH |
408 | !(type == ICMPV6_PARAMPROB && |
409 | code == ICMPV6_UNK_OPTION && | |
1da177e4 LT |
410 | (opt_unrec(skb, info)))) |
411 | return; | |
412 | ||
413 | saddr = NULL; | |
414 | } | |
415 | ||
416 | addr_type = ipv6_addr_type(&hdr->saddr); | |
417 | ||
418 | /* | |
419 | * Source addr check | |
420 | */ | |
421 | ||
422 | if (addr_type & IPV6_ADDR_LINKLOCAL) | |
423 | iif = skb->dev->ifindex; | |
424 | ||
425 | /* | |
8de3351e YH |
426 | * Must not send error if the source does not uniquely |
427 | * identify a single node (RFC2463 Section 2.4). | |
428 | * We check unspecified / multicast addresses here, | |
429 | * and anycast addresses will be checked later. | |
1da177e4 LT |
430 | */ |
431 | if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { | |
64ce2073 | 432 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n"); |
1da177e4 LT |
433 | return; |
434 | } | |
435 | ||
1ab1457c | 436 | /* |
1da177e4 LT |
437 | * Never answer to a ICMP packet. |
438 | */ | |
439 | if (is_ineligible(skb)) { | |
64ce2073 | 440 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: no reply to icmp error\n"); |
1da177e4 LT |
441 | return; |
442 | } | |
443 | ||
79383236 MN |
444 | mip6_addr_swap(skb); |
445 | ||
4c9483b2 DM |
446 | memset(&fl6, 0, sizeof(fl6)); |
447 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
4e3fd7a0 | 448 | fl6.daddr = hdr->saddr; |
1da177e4 | 449 | if (saddr) |
4e3fd7a0 | 450 | fl6.saddr = *saddr; |
4c9483b2 | 451 | fl6.flowi6_oif = iif; |
1958b856 DM |
452 | fl6.fl6_icmp_type = type; |
453 | fl6.fl6_icmp_code = code; | |
4c9483b2 | 454 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
1da177e4 | 455 | |
fdc0bde9 DL |
456 | sk = icmpv6_xmit_lock(net); |
457 | if (sk == NULL) | |
405666db | 458 | return; |
fdc0bde9 | 459 | np = inet6_sk(sk); |
405666db | 460 | |
4c9483b2 | 461 | if (!icmpv6_xrlim_allow(sk, type, &fl6)) |
1da177e4 LT |
462 | goto out; |
463 | ||
464 | tmp_hdr.icmp6_type = type; | |
465 | tmp_hdr.icmp6_code = code; | |
466 | tmp_hdr.icmp6_cksum = 0; | |
467 | tmp_hdr.icmp6_pointer = htonl(info); | |
468 | ||
4c9483b2 DM |
469 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
470 | fl6.flowi6_oif = np->mcast_oif; | |
1da177e4 | 471 | |
4c9483b2 | 472 | dst = icmpv6_route_lookup(net, skb, sk, &fl6); |
b42835db | 473 | if (IS_ERR(dst)) |
1da177e4 | 474 | goto out; |
8de3351e | 475 | |
4c9483b2 | 476 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
1da177e4 LT |
477 | hlimit = np->mcast_hops; |
478 | else | |
479 | hlimit = np->hop_limit; | |
480 | if (hlimit < 0) | |
6b75d090 | 481 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
482 | |
483 | msg.skb = skb; | |
bbe735e4 | 484 | msg.offset = skb_network_offset(skb); |
763ecff1 | 485 | msg.type = type; |
1da177e4 LT |
486 | |
487 | len = skb->len - msg.offset; | |
488 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
489 | if (len < 0) { | |
64ce2073 | 490 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
491 | goto out_dst_release; |
492 | } | |
493 | ||
cfdf7647 ED |
494 | rcu_read_lock(); |
495 | idev = __in6_dev_get(skb->dev); | |
1da177e4 LT |
496 | |
497 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
498 | len + sizeof(struct icmp6hdr), | |
e651f03a | 499 | sizeof(struct icmp6hdr), hlimit, |
4c9483b2 | 500 | np->tclass, NULL, &fl6, (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 | 504 | ip6_flush_pending_frames(sk); |
cfdf7647 ED |
505 | } else { |
506 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
507 | len + sizeof(struct icmp6hdr)); | |
1da177e4 | 508 | } |
cfdf7647 | 509 | rcu_read_unlock(); |
1da177e4 LT |
510 | out_dst_release: |
511 | dst_release(dst); | |
512 | out: | |
405666db | 513 | icmpv6_xmit_unlock(sk); |
1da177e4 | 514 | } |
7159039a YH |
515 | EXPORT_SYMBOL(icmpv6_send); |
516 | ||
1da177e4 LT |
517 | static void icmpv6_echo_reply(struct sk_buff *skb) |
518 | { | |
c346dca1 | 519 | struct net *net = dev_net(skb->dev); |
84427d53 | 520 | struct sock *sk; |
1da177e4 | 521 | struct inet6_dev *idev; |
84427d53 | 522 | struct ipv6_pinfo *np; |
b71d1d42 | 523 | const struct in6_addr *saddr = NULL; |
cc70ab26 | 524 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 | 525 | struct icmp6hdr tmp_hdr; |
4c9483b2 | 526 | struct flowi6 fl6; |
1da177e4 LT |
527 | struct icmpv6_msg msg; |
528 | struct dst_entry *dst; | |
529 | int err = 0; | |
530 | int hlimit; | |
531 | ||
0660e03f | 532 | saddr = &ipv6_hdr(skb)->daddr; |
1da177e4 LT |
533 | |
534 | if (!ipv6_unicast_destination(skb)) | |
535 | saddr = NULL; | |
536 | ||
537 | memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); | |
538 | tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; | |
539 | ||
4c9483b2 DM |
540 | memset(&fl6, 0, sizeof(fl6)); |
541 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
4e3fd7a0 | 542 | fl6.daddr = ipv6_hdr(skb)->saddr; |
1da177e4 | 543 | if (saddr) |
4e3fd7a0 | 544 | fl6.saddr = *saddr; |
4c9483b2 | 545 | fl6.flowi6_oif = skb->dev->ifindex; |
1958b856 | 546 | fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; |
4c9483b2 | 547 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
1da177e4 | 548 | |
fdc0bde9 DL |
549 | sk = icmpv6_xmit_lock(net); |
550 | if (sk == NULL) | |
405666db | 551 | return; |
fdc0bde9 | 552 | np = inet6_sk(sk); |
405666db | 553 | |
4c9483b2 DM |
554 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
555 | fl6.flowi6_oif = np->mcast_oif; | |
1da177e4 | 556 | |
4c9483b2 | 557 | err = ip6_dst_lookup(sk, &dst, &fl6); |
1da177e4 LT |
558 | if (err) |
559 | goto out; | |
4c9483b2 | 560 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
452edd59 | 561 | if (IS_ERR(dst)) |
e104411b | 562 | goto out; |
1da177e4 | 563 | |
4c9483b2 | 564 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
1da177e4 LT |
565 | hlimit = np->mcast_hops; |
566 | else | |
567 | hlimit = np->hop_limit; | |
568 | if (hlimit < 0) | |
6b75d090 | 569 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 | 570 | |
cfdf7647 | 571 | idev = __in6_dev_get(skb->dev); |
1da177e4 LT |
572 | |
573 | msg.skb = skb; | |
574 | msg.offset = 0; | |
763ecff1 | 575 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
576 | |
577 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
4c9483b2 | 578 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6, |
13b52cd4 BH |
579 | (struct rt6_info*)dst, MSG_DONTWAIT, |
580 | np->dontfrag); | |
1da177e4 LT |
581 | |
582 | if (err) { | |
00d9d6a1 | 583 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 | 584 | ip6_flush_pending_frames(sk); |
cfdf7647 ED |
585 | } else { |
586 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
587 | skb->len + sizeof(struct icmp6hdr)); | |
1da177e4 | 588 | } |
1da177e4 | 589 | dst_release(dst); |
1ab1457c | 590 | out: |
405666db | 591 | icmpv6_xmit_unlock(sk); |
1da177e4 LT |
592 | } |
593 | ||
d5fdd6ba | 594 | static void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
1da177e4 | 595 | { |
41135cc8 | 596 | const struct inet6_protocol *ipprot; |
1da177e4 LT |
597 | int inner_offset; |
598 | int hash; | |
599 | u8 nexthdr; | |
75f2811c | 600 | __be16 frag_off; |
1da177e4 LT |
601 | |
602 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
603 | return; | |
604 | ||
605 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
606 | if (ipv6_ext_hdr(nexthdr)) { | |
607 | /* now skip over extension headers */ | |
75f2811c JG |
608 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), |
609 | &nexthdr, &frag_off); | |
1da177e4 LT |
610 | if (inner_offset<0) |
611 | return; | |
612 | } else { | |
613 | inner_offset = sizeof(struct ipv6hdr); | |
614 | } | |
615 | ||
616 | /* Checkin header including 8 bytes of inner protocol header. */ | |
617 | if (!pskb_may_pull(skb, inner_offset+8)) | |
618 | return; | |
619 | ||
1da177e4 LT |
620 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
621 | Without this we will not able f.e. to make source routed | |
622 | pmtu discovery. | |
623 | Corresponding argument (opt) to notifiers is already added. | |
624 | --ANK (980726) | |
625 | */ | |
626 | ||
627 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
628 | ||
629 | rcu_read_lock(); | |
630 | ipprot = rcu_dereference(inet6_protos[hash]); | |
631 | if (ipprot && ipprot->err_handler) | |
632 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
633 | rcu_read_unlock(); | |
634 | ||
69d6da0b | 635 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 636 | } |
1ab1457c | 637 | |
1da177e4 LT |
638 | /* |
639 | * Handle icmp messages | |
640 | */ | |
641 | ||
e5bbef20 | 642 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 643 | { |
1da177e4 LT |
644 | struct net_device *dev = skb->dev; |
645 | struct inet6_dev *idev = __in6_dev_get(dev); | |
b71d1d42 ED |
646 | const struct in6_addr *saddr, *daddr; |
647 | const struct ipv6hdr *orig_hdr; | |
1da177e4 | 648 | struct icmp6hdr *hdr; |
d5fdd6ba | 649 | u8 type; |
1da177e4 | 650 | |
aebcf82c | 651 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 652 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
653 | int nh; |
654 | ||
def8b4fa | 655 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
656 | XFRM_STATE_ICMP)) |
657 | goto drop_no_count; | |
658 | ||
8b7817f3 HX |
659 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
660 | goto drop_no_count; | |
661 | ||
662 | nh = skb_network_offset(skb); | |
663 | skb_set_network_header(skb, sizeof(*hdr)); | |
664 | ||
665 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
666 | goto drop_no_count; | |
667 | ||
668 | skb_set_network_header(skb, nh); | |
669 | } | |
670 | ||
e41b5368 | 671 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
1da177e4 | 672 | |
0660e03f ACM |
673 | saddr = &ipv6_hdr(skb)->saddr; |
674 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
675 | |
676 | /* Perform checksum. */ | |
fb286bb2 | 677 | switch (skb->ip_summed) { |
84fa7933 | 678 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
679 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
680 | skb->csum)) | |
681 | break; | |
682 | /* fall through */ | |
683 | case CHECKSUM_NONE: | |
868c86bc AV |
684 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
685 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 686 | if (__skb_checksum_complete(skb)) { |
5b095d98 | 687 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", |
0c6ce78a | 688 | saddr, daddr); |
1da177e4 LT |
689 | goto discard_it; |
690 | } | |
691 | } | |
692 | ||
8cf22943 HX |
693 | if (!pskb_pull(skb, sizeof(*hdr))) |
694 | goto discard_it; | |
1da177e4 | 695 | |
cc70ab26 | 696 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
697 | |
698 | type = hdr->icmp6_type; | |
699 | ||
55d43808 | 700 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
1da177e4 LT |
701 | |
702 | switch (type) { | |
703 | case ICMPV6_ECHO_REQUEST: | |
704 | icmpv6_echo_reply(skb); | |
705 | break; | |
706 | ||
707 | case ICMPV6_ECHO_REPLY: | |
708 | /* we couldn't care less */ | |
709 | break; | |
710 | ||
711 | case ICMPV6_PKT_TOOBIG: | |
712 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
713 | standard destination cache. Seems, only "advanced" | |
714 | destination cache will allow to solve this problem | |
715 | --ANK (980726) | |
716 | */ | |
717 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
718 | goto discard_it; | |
cc70ab26 | 719 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
720 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
721 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
722 | ntohl(hdr->icmp6_mtu)); | |
723 | ||
724 | /* | |
725 | * Drop through to notify | |
726 | */ | |
727 | ||
728 | case ICMPV6_DEST_UNREACH: | |
729 | case ICMPV6_TIME_EXCEED: | |
730 | case ICMPV6_PARAMPROB: | |
731 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
732 | break; | |
733 | ||
734 | case NDISC_ROUTER_SOLICITATION: | |
735 | case NDISC_ROUTER_ADVERTISEMENT: | |
736 | case NDISC_NEIGHBOUR_SOLICITATION: | |
737 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
738 | case NDISC_REDIRECT: | |
739 | ndisc_rcv(skb); | |
740 | break; | |
741 | ||
742 | case ICMPV6_MGM_QUERY: | |
743 | igmp6_event_query(skb); | |
744 | break; | |
745 | ||
746 | case ICMPV6_MGM_REPORT: | |
747 | igmp6_event_report(skb); | |
748 | break; | |
749 | ||
750 | case ICMPV6_MGM_REDUCTION: | |
751 | case ICMPV6_NI_QUERY: | |
752 | case ICMPV6_NI_REPLY: | |
753 | case ICMPV6_MLD2_REPORT: | |
754 | case ICMPV6_DHAAD_REQUEST: | |
755 | case ICMPV6_DHAAD_REPLY: | |
756 | case ICMPV6_MOBILE_PREFIX_SOL: | |
757 | case ICMPV6_MOBILE_PREFIX_ADV: | |
758 | break; | |
759 | ||
760 | default: | |
64ce2073 | 761 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
762 | |
763 | /* informational */ | |
764 | if (type & ICMPV6_INFOMSG_MASK) | |
765 | break; | |
766 | ||
1ab1457c YH |
767 | /* |
768 | * error of unknown type. | |
769 | * must pass to upper level | |
1da177e4 LT |
770 | */ |
771 | ||
772 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
773 | } |
774 | ||
1da177e4 LT |
775 | kfree_skb(skb); |
776 | return 0; | |
777 | ||
778 | discard_it: | |
e41b5368 | 779 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
8b7817f3 | 780 | drop_no_count: |
1da177e4 LT |
781 | kfree_skb(skb); |
782 | return 0; | |
783 | } | |
784 | ||
4c9483b2 | 785 | void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, |
95e41e93 YH |
786 | u8 type, |
787 | const struct in6_addr *saddr, | |
788 | const struct in6_addr *daddr, | |
789 | int oif) | |
790 | { | |
4c9483b2 | 791 | memset(fl6, 0, sizeof(*fl6)); |
4e3fd7a0 AD |
792 | fl6->saddr = *saddr; |
793 | fl6->daddr = *daddr; | |
4c9483b2 | 794 | fl6->flowi6_proto = IPPROTO_ICMPV6; |
1958b856 DM |
795 | fl6->fl6_icmp_type = type; |
796 | fl6->fl6_icmp_code = 0; | |
4c9483b2 DM |
797 | fl6->flowi6_oif = oif; |
798 | security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); | |
95e41e93 YH |
799 | } |
800 | ||
640c41c7 | 801 | /* |
b7e729c4 | 802 | * Special lock-class for __icmpv6_sk: |
640c41c7 IM |
803 | */ |
804 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
805 | ||
98c6d1b2 | 806 | static int __net_init icmpv6_sk_init(struct net *net) |
1da177e4 LT |
807 | { |
808 | struct sock *sk; | |
809 | int err, i, j; | |
810 | ||
98c6d1b2 DL |
811 | net->ipv6.icmp_sk = |
812 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
813 | if (net->ipv6.icmp_sk == NULL) | |
79c91159 DL |
814 | return -ENOMEM; |
815 | ||
6f912042 | 816 | for_each_possible_cpu(i) { |
1ed8516f DL |
817 | err = inet_ctl_sock_create(&sk, PF_INET6, |
818 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
1da177e4 LT |
819 | if (err < 0) { |
820 | printk(KERN_ERR | |
821 | "Failed to initialize the ICMP6 control socket " | |
822 | "(err %d).\n", | |
823 | err); | |
824 | goto fail; | |
825 | } | |
826 | ||
1ed8516f | 827 | net->ipv6.icmp_sk[i] = sk; |
5c8cafd6 | 828 | |
640c41c7 IM |
829 | /* |
830 | * Split off their lock-class, because sk->sk_dst_lock | |
831 | * gets used from softirqs, which is safe for | |
b7e729c4 | 832 | * __icmpv6_sk (because those never get directly used |
640c41c7 IM |
833 | * via userspace syscalls), but unsafe for normal sockets. |
834 | */ | |
835 | lockdep_set_class(&sk->sk_dst_lock, | |
836 | &icmpv6_socket_sk_dst_lock_key); | |
1da177e4 LT |
837 | |
838 | /* Enough space for 2 64K ICMP packets, including | |
839 | * sk_buff struct overhead. | |
840 | */ | |
87fb4b7b | 841 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
1da177e4 | 842 | } |
1da177e4 LT |
843 | return 0; |
844 | ||
845 | fail: | |
5c8cafd6 | 846 | for (j = 0; j < i; j++) |
1ed8516f | 847 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[j]); |
98c6d1b2 | 848 | kfree(net->ipv6.icmp_sk); |
1da177e4 LT |
849 | return err; |
850 | } | |
851 | ||
98c6d1b2 | 852 | static void __net_exit icmpv6_sk_exit(struct net *net) |
1da177e4 LT |
853 | { |
854 | int i; | |
855 | ||
6f912042 | 856 | for_each_possible_cpu(i) { |
1ed8516f | 857 | inet_ctl_sock_destroy(net->ipv6.icmp_sk[i]); |
1da177e4 | 858 | } |
98c6d1b2 DL |
859 | kfree(net->ipv6.icmp_sk); |
860 | } | |
861 | ||
8ed7edce | 862 | static struct pernet_operations icmpv6_sk_ops = { |
98c6d1b2 DL |
863 | .init = icmpv6_sk_init, |
864 | .exit = icmpv6_sk_exit, | |
865 | }; | |
866 | ||
867 | int __init icmpv6_init(void) | |
868 | { | |
869 | int err; | |
870 | ||
871 | err = register_pernet_subsys(&icmpv6_sk_ops); | |
872 | if (err < 0) | |
873 | return err; | |
874 | ||
875 | err = -EAGAIN; | |
876 | if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) | |
877 | goto fail; | |
878 | return 0; | |
879 | ||
880 | fail: | |
881 | printk(KERN_ERR "Failed to register ICMP6 protocol\n"); | |
882 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
883 | return err; | |
884 | } | |
885 | ||
8ed7edce | 886 | void icmpv6_cleanup(void) |
98c6d1b2 DL |
887 | { |
888 | unregister_pernet_subsys(&icmpv6_sk_ops); | |
1da177e4 LT |
889 | inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
890 | } | |
891 | ||
98c6d1b2 | 892 | |
9b5b5cff | 893 | static const struct icmp6_err { |
1da177e4 LT |
894 | int err; |
895 | int fatal; | |
896 | } tab_unreach[] = { | |
897 | { /* NOROUTE */ | |
898 | .err = ENETUNREACH, | |
899 | .fatal = 0, | |
900 | }, | |
901 | { /* ADM_PROHIBITED */ | |
902 | .err = EACCES, | |
903 | .fatal = 1, | |
904 | }, | |
905 | { /* Was NOT_NEIGHBOUR, now reserved */ | |
906 | .err = EHOSTUNREACH, | |
907 | .fatal = 0, | |
908 | }, | |
909 | { /* ADDR_UNREACH */ | |
910 | .err = EHOSTUNREACH, | |
911 | .fatal = 0, | |
912 | }, | |
913 | { /* PORT_UNREACH */ | |
914 | .err = ECONNREFUSED, | |
915 | .fatal = 1, | |
916 | }, | |
917 | }; | |
918 | ||
d5fdd6ba | 919 | int icmpv6_err_convert(u8 type, u8 code, int *err) |
1da177e4 LT |
920 | { |
921 | int fatal = 0; | |
922 | ||
923 | *err = EPROTO; | |
924 | ||
925 | switch (type) { | |
926 | case ICMPV6_DEST_UNREACH: | |
927 | fatal = 1; | |
928 | if (code <= ICMPV6_PORT_UNREACH) { | |
929 | *err = tab_unreach[code].err; | |
930 | fatal = tab_unreach[code].fatal; | |
931 | } | |
932 | break; | |
933 | ||
934 | case ICMPV6_PKT_TOOBIG: | |
935 | *err = EMSGSIZE; | |
936 | break; | |
1ab1457c | 937 | |
1da177e4 LT |
938 | case ICMPV6_PARAMPROB: |
939 | *err = EPROTO; | |
940 | fatal = 1; | |
941 | break; | |
942 | ||
943 | case ICMPV6_TIME_EXCEED: | |
944 | *err = EHOSTUNREACH; | |
945 | break; | |
3ff50b79 | 946 | } |
1da177e4 LT |
947 | |
948 | return fatal; | |
949 | } | |
950 | ||
7159039a YH |
951 | EXPORT_SYMBOL(icmpv6_err_convert); |
952 | ||
1da177e4 | 953 | #ifdef CONFIG_SYSCTL |
760f2d01 | 954 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 | 955 | { |
1da177e4 | 956 | .procname = "ratelimit", |
41a76906 | 957 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
958 | .maxlen = sizeof(int), |
959 | .mode = 0644, | |
6d9f239a | 960 | .proc_handler = proc_dointvec_ms_jiffies, |
1da177e4 | 961 | }, |
f8572d8f | 962 | { }, |
1da177e4 | 963 | }; |
760f2d01 | 964 | |
2c8c1e72 | 965 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
760f2d01 DL |
966 | { |
967 | struct ctl_table *table; | |
968 | ||
969 | table = kmemdup(ipv6_icmp_table_template, | |
970 | sizeof(ipv6_icmp_table_template), | |
971 | GFP_KERNEL); | |
5ee09105 YH |
972 | |
973 | if (table) | |
974 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
975 | ||
760f2d01 DL |
976 | return table; |
977 | } | |
1da177e4 LT |
978 | #endif |
979 |