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 | ||
f3213831 JP |
32 | #define pr_fmt(fmt) "IPv6: " fmt |
33 | ||
1da177e4 LT |
34 | #include <linux/module.h> |
35 | #include <linux/errno.h> | |
36 | #include <linux/types.h> | |
37 | #include <linux/socket.h> | |
38 | #include <linux/in.h> | |
39 | #include <linux/kernel.h> | |
1da177e4 LT |
40 | #include <linux/sockios.h> |
41 | #include <linux/net.h> | |
42 | #include <linux/skbuff.h> | |
43 | #include <linux/init.h> | |
763ecff1 | 44 | #include <linux/netfilter.h> |
5a0e3ad6 | 45 | #include <linux/slab.h> |
1da177e4 LT |
46 | |
47 | #ifdef CONFIG_SYSCTL | |
48 | #include <linux/sysctl.h> | |
49 | #endif | |
50 | ||
51 | #include <linux/inet.h> | |
52 | #include <linux/netdevice.h> | |
53 | #include <linux/icmpv6.h> | |
54 | ||
55 | #include <net/ip.h> | |
56 | #include <net/sock.h> | |
57 | ||
58 | #include <net/ipv6.h> | |
59 | #include <net/ip6_checksum.h> | |
60 | #include <net/protocol.h> | |
61 | #include <net/raw.h> | |
62 | #include <net/rawv6.h> | |
63 | #include <net/transp_v6.h> | |
64 | #include <net/ip6_route.h> | |
65 | #include <net/addrconf.h> | |
66 | #include <net/icmp.h> | |
8b7817f3 | 67 | #include <net/xfrm.h> |
1ed8516f | 68 | #include <net/inet_common.h> |
1da177e4 LT |
69 | |
70 | #include <asm/uaccess.h> | |
1da177e4 | 71 | |
1da177e4 LT |
72 | /* |
73 | * The ICMP socket(s). This is the most convenient way to flow control | |
74 | * our ICMP output as well as maintain a clean interface throughout | |
75 | * all layers. All Socketless IP sends will soon be gone. | |
76 | * | |
77 | * On SMP we have one ICMP socket per-cpu. | |
78 | */ | |
98c6d1b2 DL |
79 | static inline struct sock *icmpv6_sk(struct net *net) |
80 | { | |
81 | return net->ipv6.icmp_sk[smp_processor_id()]; | |
82 | } | |
1da177e4 | 83 | |
e5bbef20 | 84 | static int icmpv6_rcv(struct sk_buff *skb); |
1da177e4 | 85 | |
41135cc8 | 86 | static const struct inet6_protocol icmpv6_protocol = { |
1da177e4 | 87 | .handler = icmpv6_rcv, |
8b7817f3 | 88 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
1da177e4 LT |
89 | }; |
90 | ||
fdc0bde9 | 91 | static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) |
1da177e4 | 92 | { |
fdc0bde9 DL |
93 | struct sock *sk; |
94 | ||
1da177e4 LT |
95 | local_bh_disable(); |
96 | ||
fdc0bde9 | 97 | sk = icmpv6_sk(net); |
405666db | 98 | if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
1da177e4 LT |
99 | /* This can happen if the output path (f.e. SIT or |
100 | * ip6ip6 tunnel) signals dst_link_failure() for an | |
101 | * outgoing ICMP6 packet. | |
102 | */ | |
103 | local_bh_enable(); | |
fdc0bde9 | 104 | return NULL; |
1da177e4 | 105 | } |
fdc0bde9 | 106 | return sk; |
1da177e4 LT |
107 | } |
108 | ||
405666db | 109 | static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
1da177e4 | 110 | { |
405666db | 111 | spin_unlock_bh(&sk->sk_lock.slock); |
1da177e4 LT |
112 | } |
113 | ||
1ab1457c | 114 | /* |
1da177e4 LT |
115 | * Slightly more convenient version of icmpv6_send. |
116 | */ | |
d5fdd6ba | 117 | void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) |
1da177e4 | 118 | { |
3ffe533c | 119 | icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos); |
1da177e4 LT |
120 | kfree_skb(skb); |
121 | } | |
122 | ||
123 | /* | |
124 | * Figure out, may we reply to this packet with icmp error. | |
125 | * | |
126 | * We do not reply, if: | |
127 | * - it was icmp error message. | |
128 | * - it is truncated, so that it is known, that protocol is ICMPV6 | |
129 | * (i.e. in the middle of some exthdr) | |
130 | * | |
131 | * --ANK (980726) | |
132 | */ | |
133 | ||
a50feda5 | 134 | static bool is_ineligible(const struct sk_buff *skb) |
1da177e4 | 135 | { |
0660e03f | 136 | int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
1da177e4 | 137 | int len = skb->len - ptr; |
0660e03f | 138 | __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 139 | __be16 frag_off; |
1da177e4 LT |
140 | |
141 | if (len < 0) | |
a50feda5 | 142 | return true; |
1da177e4 | 143 | |
75f2811c | 144 | ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); |
1da177e4 | 145 | if (ptr < 0) |
a50feda5 | 146 | return false; |
1da177e4 LT |
147 | if (nexthdr == IPPROTO_ICMPV6) { |
148 | u8 _type, *tp; | |
149 | tp = skb_header_pointer(skb, | |
150 | ptr+offsetof(struct icmp6hdr, icmp6_type), | |
151 | sizeof(_type), &_type); | |
152 | if (tp == NULL || | |
153 | !(*tp & ICMPV6_INFOMSG_MASK)) | |
a50feda5 | 154 | return true; |
1da177e4 | 155 | } |
a50feda5 | 156 | return false; |
1da177e4 LT |
157 | } |
158 | ||
1ab1457c YH |
159 | /* |
160 | * Check the ICMP output rate limit | |
1da177e4 | 161 | */ |
92d86829 | 162 | static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
4c9483b2 | 163 | struct flowi6 *fl6) |
1da177e4 LT |
164 | { |
165 | struct dst_entry *dst; | |
3b1e0a65 | 166 | struct net *net = sock_net(sk); |
92d86829 | 167 | bool res = false; |
1da177e4 LT |
168 | |
169 | /* Informational messages are not limited. */ | |
170 | if (type & ICMPV6_INFOMSG_MASK) | |
92d86829 | 171 | return true; |
1da177e4 LT |
172 | |
173 | /* Do not limit pmtu discovery, it would break it. */ | |
174 | if (type == ICMPV6_PKT_TOOBIG) | |
92d86829 | 175 | return true; |
1da177e4 | 176 | |
1ab1457c | 177 | /* |
1da177e4 LT |
178 | * Look up the output route. |
179 | * XXX: perhaps the expire for routing entries cloned by | |
180 | * this lookup should be more aggressive (not longer than timeout). | |
181 | */ | |
4c9483b2 | 182 | dst = ip6_route_output(net, sk, fl6); |
1da177e4 | 183 | if (dst->error) { |
3bd653c8 | 184 | IP6_INC_STATS(net, ip6_dst_idev(dst), |
a11d206d | 185 | IPSTATS_MIB_OUTNOROUTES); |
1da177e4 | 186 | } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
92d86829 | 187 | res = true; |
1da177e4 LT |
188 | } else { |
189 | struct rt6_info *rt = (struct rt6_info *)dst; | |
9a43b709 | 190 | int tmo = net->ipv6.sysctl.icmpv6_time; |
1da177e4 LT |
191 | |
192 | /* Give more bandwidth to wider prefixes. */ | |
193 | if (rt->rt6i_dst.plen < 128) | |
194 | tmo >>= ((128 - rt->rt6i_dst.plen)>>5); | |
195 | ||
92d86829 DM |
196 | if (!rt->rt6i_peer) |
197 | rt6_bind_peer(rt, 1); | |
198 | res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo); | |
1da177e4 LT |
199 | } |
200 | dst_release(dst); | |
201 | return res; | |
202 | } | |
203 | ||
204 | /* | |
205 | * an inline helper for the "simple" if statement below | |
206 | * checks if parameter problem report is caused by an | |
1ab1457c | 207 | * unrecognized IPv6 option that has the Option Type |
1da177e4 LT |
208 | * highest-order two bits set to 10 |
209 | */ | |
210 | ||
a50feda5 | 211 | static bool opt_unrec(struct sk_buff *skb, __u32 offset) |
1da177e4 LT |
212 | { |
213 | u8 _optval, *op; | |
214 | ||
bbe735e4 | 215 | offset += skb_network_offset(skb); |
1da177e4 LT |
216 | op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
217 | if (op == NULL) | |
a50feda5 | 218 | return true; |
1da177e4 LT |
219 | return (*op & 0xC0) == 0x80; |
220 | } | |
221 | ||
4c9483b2 | 222 | static int icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, struct icmp6hdr *thdr, int len) |
1da177e4 LT |
223 | { |
224 | struct sk_buff *skb; | |
225 | struct icmp6hdr *icmp6h; | |
226 | int err = 0; | |
227 | ||
228 | if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) | |
229 | goto out; | |
230 | ||
cc70ab26 | 231 | icmp6h = icmp6_hdr(skb); |
1da177e4 LT |
232 | memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
233 | icmp6h->icmp6_cksum = 0; | |
234 | ||
235 | if (skb_queue_len(&sk->sk_write_queue) == 1) { | |
07f0757a | 236 | skb->csum = csum_partial(icmp6h, |
1da177e4 | 237 | sizeof(struct icmp6hdr), skb->csum); |
4c9483b2 DM |
238 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
239 | &fl6->daddr, | |
240 | len, fl6->flowi6_proto, | |
1da177e4 LT |
241 | skb->csum); |
242 | } else { | |
868c86bc | 243 | __wsum tmp_csum = 0; |
1da177e4 LT |
244 | |
245 | skb_queue_walk(&sk->sk_write_queue, skb) { | |
246 | tmp_csum = csum_add(tmp_csum, skb->csum); | |
247 | } | |
248 | ||
07f0757a | 249 | tmp_csum = csum_partial(icmp6h, |
1da177e4 | 250 | sizeof(struct icmp6hdr), tmp_csum); |
4c9483b2 DM |
251 | icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
252 | &fl6->daddr, | |
253 | len, fl6->flowi6_proto, | |
868c86bc | 254 | tmp_csum); |
1da177e4 | 255 | } |
1da177e4 LT |
256 | ip6_push_pending_frames(sk); |
257 | out: | |
258 | return err; | |
259 | } | |
260 | ||
261 | struct icmpv6_msg { | |
262 | struct sk_buff *skb; | |
263 | int offset; | |
763ecff1 | 264 | uint8_t type; |
1da177e4 LT |
265 | }; |
266 | ||
267 | static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) | |
268 | { | |
269 | struct icmpv6_msg *msg = (struct icmpv6_msg *) from; | |
270 | struct sk_buff *org_skb = msg->skb; | |
5f92a738 | 271 | __wsum csum = 0; |
1da177e4 LT |
272 | |
273 | csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, | |
274 | to, len, csum); | |
275 | skb->csum = csum_block_add(skb->csum, csum, odd); | |
763ecff1 YK |
276 | if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
277 | nf_ct_attach(skb, org_skb); | |
1da177e4 LT |
278 | return 0; |
279 | } | |
280 | ||
59fbb3a6 | 281 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
79383236 MN |
282 | static void mip6_addr_swap(struct sk_buff *skb) |
283 | { | |
0660e03f | 284 | struct ipv6hdr *iph = ipv6_hdr(skb); |
79383236 MN |
285 | struct inet6_skb_parm *opt = IP6CB(skb); |
286 | struct ipv6_destopt_hao *hao; | |
287 | struct in6_addr tmp; | |
288 | int off; | |
289 | ||
290 | if (opt->dsthao) { | |
291 | off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); | |
292 | if (likely(off >= 0)) { | |
d56f90a7 ACM |
293 | hao = (struct ipv6_destopt_hao *) |
294 | (skb_network_header(skb) + off); | |
4e3fd7a0 AD |
295 | tmp = iph->saddr; |
296 | iph->saddr = hao->addr; | |
297 | hao->addr = tmp; | |
79383236 MN |
298 | } |
299 | } | |
300 | } | |
301 | #else | |
302 | static inline void mip6_addr_swap(struct sk_buff *skb) {} | |
303 | #endif | |
304 | ||
b42835db | 305 | static struct dst_entry *icmpv6_route_lookup(struct net *net, struct sk_buff *skb, |
4c9483b2 | 306 | struct sock *sk, struct flowi6 *fl6) |
b42835db DM |
307 | { |
308 | struct dst_entry *dst, *dst2; | |
4c9483b2 | 309 | struct flowi6 fl2; |
b42835db DM |
310 | int err; |
311 | ||
4c9483b2 | 312 | err = ip6_dst_lookup(sk, &dst, fl6); |
b42835db DM |
313 | if (err) |
314 | return ERR_PTR(err); | |
315 | ||
316 | /* | |
317 | * We won't send icmp if the destination is known | |
318 | * anycast. | |
319 | */ | |
320 | if (((struct rt6_info *)dst)->rt6i_flags & RTF_ANYCAST) { | |
321 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6_send: acast source\n"); | |
322 | dst_release(dst); | |
323 | return ERR_PTR(-EINVAL); | |
324 | } | |
325 | ||
326 | /* No need to clone since we're just using its address. */ | |
327 | dst2 = dst; | |
328 | ||
4c9483b2 | 329 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); |
452edd59 | 330 | if (!IS_ERR(dst)) { |
b42835db DM |
331 | if (dst != dst2) |
332 | return dst; | |
452edd59 DM |
333 | } else { |
334 | if (PTR_ERR(dst) == -EPERM) | |
335 | dst = NULL; | |
336 | else | |
337 | return dst; | |
b42835db DM |
338 | } |
339 | ||
4c9483b2 | 340 | err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); |
b42835db DM |
341 | if (err) |
342 | goto relookup_failed; | |
343 | ||
344 | err = ip6_dst_lookup(sk, &dst2, &fl2); | |
345 | if (err) | |
346 | goto relookup_failed; | |
347 | ||
4c9483b2 | 348 | dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); |
452edd59 | 349 | if (!IS_ERR(dst2)) { |
b42835db DM |
350 | dst_release(dst); |
351 | dst = dst2; | |
452edd59 DM |
352 | } else { |
353 | err = PTR_ERR(dst2); | |
354 | if (err == -EPERM) { | |
355 | dst_release(dst); | |
356 | return dst2; | |
357 | } else | |
358 | goto relookup_failed; | |
b42835db DM |
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; | |
b71d1d42 | 377 | const struct in6_addr *saddr = NULL; |
1da177e4 LT |
378 | struct dst_entry *dst; |
379 | struct icmp6hdr tmp_hdr; | |
4c9483b2 | 380 | struct flowi6 fl6; |
1da177e4 LT |
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 | ||
4c9483b2 DM |
447 | memset(&fl6, 0, sizeof(fl6)); |
448 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
4e3fd7a0 | 449 | fl6.daddr = hdr->saddr; |
1da177e4 | 450 | if (saddr) |
4e3fd7a0 | 451 | fl6.saddr = *saddr; |
4c9483b2 | 452 | fl6.flowi6_oif = iif; |
1958b856 DM |
453 | fl6.fl6_icmp_type = type; |
454 | fl6.fl6_icmp_code = code; | |
4c9483b2 | 455 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
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 | |
4c9483b2 | 462 | if (!icmpv6_xrlim_allow(sk, type, &fl6)) |
1da177e4 LT |
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 | ||
4c9483b2 DM |
470 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
471 | fl6.flowi6_oif = np->mcast_oif; | |
c4062dfc EH |
472 | else if (!fl6.flowi6_oif) |
473 | fl6.flowi6_oif = np->ucast_oif; | |
1da177e4 | 474 | |
4c9483b2 | 475 | dst = icmpv6_route_lookup(net, skb, sk, &fl6); |
b42835db | 476 | if (IS_ERR(dst)) |
1da177e4 | 477 | goto out; |
8de3351e | 478 | |
4c9483b2 | 479 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
1da177e4 LT |
480 | hlimit = np->mcast_hops; |
481 | else | |
482 | hlimit = np->hop_limit; | |
483 | if (hlimit < 0) | |
6b75d090 | 484 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 LT |
485 | |
486 | msg.skb = skb; | |
bbe735e4 | 487 | msg.offset = skb_network_offset(skb); |
763ecff1 | 488 | msg.type = type; |
1da177e4 LT |
489 | |
490 | len = skb->len - msg.offset; | |
491 | len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) -sizeof(struct icmp6hdr)); | |
492 | if (len < 0) { | |
64ce2073 | 493 | LIMIT_NETDEBUG(KERN_DEBUG "icmp: len problem\n"); |
1da177e4 LT |
494 | goto out_dst_release; |
495 | } | |
496 | ||
cfdf7647 ED |
497 | rcu_read_lock(); |
498 | idev = __in6_dev_get(skb->dev); | |
1da177e4 LT |
499 | |
500 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, | |
501 | len + sizeof(struct icmp6hdr), | |
e651f03a | 502 | sizeof(struct icmp6hdr), hlimit, |
a2d91a09 | 503 | np->tclass, NULL, &fl6, (struct rt6_info *)dst, |
13b52cd4 | 504 | MSG_DONTWAIT, np->dontfrag); |
1da177e4 | 505 | if (err) { |
00d9d6a1 | 506 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 | 507 | ip6_flush_pending_frames(sk); |
cfdf7647 ED |
508 | } else { |
509 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
510 | len + sizeof(struct icmp6hdr)); | |
1da177e4 | 511 | } |
cfdf7647 | 512 | rcu_read_unlock(); |
1da177e4 LT |
513 | out_dst_release: |
514 | dst_release(dst); | |
515 | out: | |
405666db | 516 | icmpv6_xmit_unlock(sk); |
1da177e4 | 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; |
b71d1d42 | 526 | const struct in6_addr *saddr = NULL; |
cc70ab26 | 527 | struct icmp6hdr *icmph = icmp6_hdr(skb); |
1da177e4 | 528 | struct icmp6hdr tmp_hdr; |
4c9483b2 | 529 | struct flowi6 fl6; |
1da177e4 LT |
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 | ||
4c9483b2 DM |
543 | memset(&fl6, 0, sizeof(fl6)); |
544 | fl6.flowi6_proto = IPPROTO_ICMPV6; | |
4e3fd7a0 | 545 | fl6.daddr = ipv6_hdr(skb)->saddr; |
1da177e4 | 546 | if (saddr) |
4e3fd7a0 | 547 | fl6.saddr = *saddr; |
4c9483b2 | 548 | fl6.flowi6_oif = skb->dev->ifindex; |
1958b856 | 549 | fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; |
4c9483b2 | 550 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
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 | |
4c9483b2 DM |
557 | if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
558 | fl6.flowi6_oif = np->mcast_oif; | |
c4062dfc EH |
559 | else if (!fl6.flowi6_oif) |
560 | fl6.flowi6_oif = np->ucast_oif; | |
1da177e4 | 561 | |
4c9483b2 | 562 | err = ip6_dst_lookup(sk, &dst, &fl6); |
1da177e4 LT |
563 | if (err) |
564 | goto out; | |
4c9483b2 | 565 | dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
452edd59 | 566 | if (IS_ERR(dst)) |
e104411b | 567 | goto out; |
1da177e4 | 568 | |
4c9483b2 | 569 | if (ipv6_addr_is_multicast(&fl6.daddr)) |
1da177e4 LT |
570 | hlimit = np->mcast_hops; |
571 | else | |
572 | hlimit = np->hop_limit; | |
573 | if (hlimit < 0) | |
6b75d090 | 574 | hlimit = ip6_dst_hoplimit(dst); |
1da177e4 | 575 | |
cfdf7647 | 576 | idev = __in6_dev_get(skb->dev); |
1da177e4 LT |
577 | |
578 | msg.skb = skb; | |
579 | msg.offset = 0; | |
763ecff1 | 580 | msg.type = ICMPV6_ECHO_REPLY; |
1da177e4 LT |
581 | |
582 | err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr), | |
4c9483b2 | 583 | sizeof(struct icmp6hdr), hlimit, np->tclass, NULL, &fl6, |
a2d91a09 | 584 | (struct rt6_info *)dst, MSG_DONTWAIT, |
13b52cd4 | 585 | np->dontfrag); |
1da177e4 LT |
586 | |
587 | if (err) { | |
00d9d6a1 | 588 | ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS); |
1da177e4 | 589 | ip6_flush_pending_frames(sk); |
cfdf7647 ED |
590 | } else { |
591 | err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, | |
592 | skb->len + sizeof(struct icmp6hdr)); | |
1da177e4 | 593 | } |
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; | |
75f2811c | 605 | __be16 frag_off; |
1da177e4 LT |
606 | |
607 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
608 | return; | |
609 | ||
610 | nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; | |
611 | if (ipv6_ext_hdr(nexthdr)) { | |
612 | /* now skip over extension headers */ | |
75f2811c JG |
613 | inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), |
614 | &nexthdr, &frag_off); | |
1da177e4 LT |
615 | if (inner_offset<0) |
616 | return; | |
617 | } else { | |
618 | inner_offset = sizeof(struct ipv6hdr); | |
619 | } | |
620 | ||
621 | /* Checkin header including 8 bytes of inner protocol header. */ | |
622 | if (!pskb_may_pull(skb, inner_offset+8)) | |
623 | return; | |
624 | ||
1da177e4 LT |
625 | /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
626 | Without this we will not able f.e. to make source routed | |
627 | pmtu discovery. | |
628 | Corresponding argument (opt) to notifiers is already added. | |
629 | --ANK (980726) | |
630 | */ | |
631 | ||
632 | hash = nexthdr & (MAX_INET_PROTOS - 1); | |
633 | ||
634 | rcu_read_lock(); | |
635 | ipprot = rcu_dereference(inet6_protos[hash]); | |
636 | if (ipprot && ipprot->err_handler) | |
637 | ipprot->err_handler(skb, NULL, type, code, inner_offset, info); | |
638 | rcu_read_unlock(); | |
639 | ||
69d6da0b | 640 | raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
1da177e4 | 641 | } |
1ab1457c | 642 | |
1da177e4 LT |
643 | /* |
644 | * Handle icmp messages | |
645 | */ | |
646 | ||
e5bbef20 | 647 | static int icmpv6_rcv(struct sk_buff *skb) |
1da177e4 | 648 | { |
1da177e4 LT |
649 | struct net_device *dev = skb->dev; |
650 | struct inet6_dev *idev = __in6_dev_get(dev); | |
b71d1d42 ED |
651 | const struct in6_addr *saddr, *daddr; |
652 | const struct ipv6hdr *orig_hdr; | |
1da177e4 | 653 | struct icmp6hdr *hdr; |
d5fdd6ba | 654 | u8 type; |
1da177e4 | 655 | |
aebcf82c | 656 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
def8b4fa | 657 | struct sec_path *sp = skb_sec_path(skb); |
8b7817f3 HX |
658 | int nh; |
659 | ||
def8b4fa | 660 | if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
aebcf82c HX |
661 | XFRM_STATE_ICMP)) |
662 | goto drop_no_count; | |
663 | ||
8b7817f3 HX |
664 | if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(*orig_hdr))) |
665 | goto drop_no_count; | |
666 | ||
667 | nh = skb_network_offset(skb); | |
668 | skb_set_network_header(skb, sizeof(*hdr)); | |
669 | ||
670 | if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) | |
671 | goto drop_no_count; | |
672 | ||
673 | skb_set_network_header(skb, nh); | |
674 | } | |
675 | ||
e41b5368 | 676 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
1da177e4 | 677 | |
0660e03f ACM |
678 | saddr = &ipv6_hdr(skb)->saddr; |
679 | daddr = &ipv6_hdr(skb)->daddr; | |
1da177e4 LT |
680 | |
681 | /* Perform checksum. */ | |
fb286bb2 | 682 | switch (skb->ip_summed) { |
84fa7933 | 683 | case CHECKSUM_COMPLETE: |
fb286bb2 HX |
684 | if (!csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_ICMPV6, |
685 | skb->csum)) | |
686 | break; | |
687 | /* fall through */ | |
688 | case CHECKSUM_NONE: | |
868c86bc AV |
689 | skb->csum = ~csum_unfold(csum_ipv6_magic(saddr, daddr, skb->len, |
690 | IPPROTO_ICMPV6, 0)); | |
fb286bb2 | 691 | if (__skb_checksum_complete(skb)) { |
5b095d98 | 692 | LIMIT_NETDEBUG(KERN_DEBUG "ICMPv6 checksum failed [%pI6 > %pI6]\n", |
0c6ce78a | 693 | saddr, daddr); |
1da177e4 LT |
694 | goto discard_it; |
695 | } | |
696 | } | |
697 | ||
8cf22943 HX |
698 | if (!pskb_pull(skb, sizeof(*hdr))) |
699 | goto discard_it; | |
1da177e4 | 700 | |
cc70ab26 | 701 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
702 | |
703 | type = hdr->icmp6_type; | |
704 | ||
55d43808 | 705 | ICMP6MSGIN_INC_STATS_BH(dev_net(dev), idev, type); |
1da177e4 LT |
706 | |
707 | switch (type) { | |
708 | case ICMPV6_ECHO_REQUEST: | |
709 | icmpv6_echo_reply(skb); | |
710 | break; | |
711 | ||
712 | case ICMPV6_ECHO_REPLY: | |
713 | /* we couldn't care less */ | |
714 | break; | |
715 | ||
716 | case ICMPV6_PKT_TOOBIG: | |
717 | /* BUGGG_FUTURE: if packet contains rthdr, we cannot update | |
718 | standard destination cache. Seems, only "advanced" | |
719 | destination cache will allow to solve this problem | |
720 | --ANK (980726) | |
721 | */ | |
722 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) | |
723 | goto discard_it; | |
cc70ab26 | 724 | hdr = icmp6_hdr(skb); |
1da177e4 LT |
725 | orig_hdr = (struct ipv6hdr *) (hdr + 1); |
726 | rt6_pmtu_discovery(&orig_hdr->daddr, &orig_hdr->saddr, dev, | |
727 | ntohl(hdr->icmp6_mtu)); | |
728 | ||
729 | /* | |
730 | * Drop through to notify | |
731 | */ | |
732 | ||
733 | case ICMPV6_DEST_UNREACH: | |
734 | case ICMPV6_TIME_EXCEED: | |
735 | case ICMPV6_PARAMPROB: | |
736 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
737 | break; | |
738 | ||
739 | case NDISC_ROUTER_SOLICITATION: | |
740 | case NDISC_ROUTER_ADVERTISEMENT: | |
741 | case NDISC_NEIGHBOUR_SOLICITATION: | |
742 | case NDISC_NEIGHBOUR_ADVERTISEMENT: | |
743 | case NDISC_REDIRECT: | |
744 | ndisc_rcv(skb); | |
745 | break; | |
746 | ||
747 | case ICMPV6_MGM_QUERY: | |
748 | igmp6_event_query(skb); | |
749 | break; | |
750 | ||
751 | case ICMPV6_MGM_REPORT: | |
752 | igmp6_event_report(skb); | |
753 | break; | |
754 | ||
755 | case ICMPV6_MGM_REDUCTION: | |
756 | case ICMPV6_NI_QUERY: | |
757 | case ICMPV6_NI_REPLY: | |
758 | case ICMPV6_MLD2_REPORT: | |
759 | case ICMPV6_DHAAD_REQUEST: | |
760 | case ICMPV6_DHAAD_REPLY: | |
761 | case ICMPV6_MOBILE_PREFIX_SOL: | |
762 | case ICMPV6_MOBILE_PREFIX_ADV: | |
763 | break; | |
764 | ||
765 | default: | |
64ce2073 | 766 | LIMIT_NETDEBUG(KERN_DEBUG "icmpv6: msg of unknown type\n"); |
1da177e4 LT |
767 | |
768 | /* informational */ | |
769 | if (type & ICMPV6_INFOMSG_MASK) | |
770 | break; | |
771 | ||
1ab1457c YH |
772 | /* |
773 | * error of unknown type. | |
774 | * must pass to upper level | |
1da177e4 LT |
775 | */ |
776 | ||
777 | icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); | |
3ff50b79 SH |
778 | } |
779 | ||
1da177e4 LT |
780 | kfree_skb(skb); |
781 | return 0; | |
782 | ||
783 | discard_it: | |
e41b5368 | 784 | ICMP6_INC_STATS_BH(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
8b7817f3 | 785 | drop_no_count: |
1da177e4 LT |
786 | kfree_skb(skb); |
787 | return 0; | |
788 | } | |
789 | ||
4c9483b2 | 790 | void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, |
95e41e93 YH |
791 | u8 type, |
792 | const struct in6_addr *saddr, | |
793 | const struct in6_addr *daddr, | |
794 | int oif) | |
795 | { | |
4c9483b2 | 796 | memset(fl6, 0, sizeof(*fl6)); |
4e3fd7a0 AD |
797 | fl6->saddr = *saddr; |
798 | fl6->daddr = *daddr; | |
4c9483b2 | 799 | fl6->flowi6_proto = IPPROTO_ICMPV6; |
1958b856 DM |
800 | fl6->fl6_icmp_type = type; |
801 | fl6->fl6_icmp_code = 0; | |
4c9483b2 DM |
802 | fl6->flowi6_oif = oif; |
803 | security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); | |
95e41e93 YH |
804 | } |
805 | ||
640c41c7 | 806 | /* |
b7e729c4 | 807 | * Special lock-class for __icmpv6_sk: |
640c41c7 IM |
808 | */ |
809 | static struct lock_class_key icmpv6_socket_sk_dst_lock_key; | |
810 | ||
98c6d1b2 | 811 | static int __net_init icmpv6_sk_init(struct net *net) |
1da177e4 LT |
812 | { |
813 | struct sock *sk; | |
814 | int err, i, j; | |
815 | ||
98c6d1b2 DL |
816 | net->ipv6.icmp_sk = |
817 | kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL); | |
818 | if (net->ipv6.icmp_sk == NULL) | |
79c91159 DL |
819 | return -ENOMEM; |
820 | ||
6f912042 | 821 | for_each_possible_cpu(i) { |
1ed8516f DL |
822 | err = inet_ctl_sock_create(&sk, PF_INET6, |
823 | SOCK_RAW, IPPROTO_ICMPV6, net); | |
1da177e4 | 824 | if (err < 0) { |
f3213831 | 825 | pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", |
1da177e4 LT |
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 | */ | |
87fb4b7b | 844 | sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
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: | |
f3213831 | 884 | pr_err("Failed to register ICMP6 protocol\n"); |
98c6d1b2 DL |
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 | } | |
7159039a YH |
953 | EXPORT_SYMBOL(icmpv6_err_convert); |
954 | ||
1da177e4 | 955 | #ifdef CONFIG_SYSCTL |
760f2d01 | 956 | ctl_table ipv6_icmp_table_template[] = { |
1da177e4 | 957 | { |
1da177e4 | 958 | .procname = "ratelimit", |
41a76906 | 959 | .data = &init_net.ipv6.sysctl.icmpv6_time, |
1da177e4 LT |
960 | .maxlen = sizeof(int), |
961 | .mode = 0644, | |
6d9f239a | 962 | .proc_handler = proc_dointvec_ms_jiffies, |
1da177e4 | 963 | }, |
f8572d8f | 964 | { }, |
1da177e4 | 965 | }; |
760f2d01 | 966 | |
2c8c1e72 | 967 | struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
760f2d01 DL |
968 | { |
969 | struct ctl_table *table; | |
970 | ||
971 | table = kmemdup(ipv6_icmp_table_template, | |
972 | sizeof(ipv6_icmp_table_template), | |
973 | GFP_KERNEL); | |
5ee09105 YH |
974 | |
975 | if (table) | |
976 | table[0].data = &net->ipv6.sysctl.icmpv6_time; | |
977 | ||
760f2d01 DL |
978 | return table; |
979 | } | |
1da177e4 LT |
980 | #endif |
981 |