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Commit | Line | Data |
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1 | /* | |
2 | * IPv6 fragment reassembly | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * | |
8 | * Based on: net/ipv4/ip_fragment.c | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
16 | /* | |
17 | * Fixes: | |
18 | * Andi Kleen Make it work with multiple hosts. | |
19 | * More RFC compliance. | |
20 | * | |
21 | * Horst von Brand Add missing #include <linux/string.h> | |
22 | * Alexey Kuznetsov SMP races, threading, cleanup. | |
23 | * Patrick McHardy LRU queue of frag heads for evictor. | |
24 | * Mitsuru KANDA @USAGI Register inet6_protocol{}. | |
25 | * David Stevens and | |
26 | * YOSHIFUJI,H. @USAGI Always remove fragment header to | |
27 | * calculate ICV correctly. | |
28 | */ | |
29 | ||
30 | #define pr_fmt(fmt) "IPv6: " fmt | |
31 | ||
32 | #include <linux/errno.h> | |
33 | #include <linux/types.h> | |
34 | #include <linux/string.h> | |
35 | #include <linux/socket.h> | |
36 | #include <linux/sockios.h> | |
37 | #include <linux/jiffies.h> | |
38 | #include <linux/net.h> | |
39 | #include <linux/list.h> | |
40 | #include <linux/netdevice.h> | |
41 | #include <linux/in6.h> | |
42 | #include <linux/ipv6.h> | |
43 | #include <linux/icmpv6.h> | |
44 | #include <linux/random.h> | |
45 | #include <linux/jhash.h> | |
46 | #include <linux/skbuff.h> | |
47 | #include <linux/slab.h> | |
48 | #include <linux/export.h> | |
49 | ||
50 | #include <net/sock.h> | |
51 | #include <net/snmp.h> | |
52 | ||
53 | #include <net/ipv6.h> | |
54 | #include <net/ip6_route.h> | |
55 | #include <net/protocol.h> | |
56 | #include <net/transp_v6.h> | |
57 | #include <net/rawv6.h> | |
58 | #include <net/ndisc.h> | |
59 | #include <net/addrconf.h> | |
60 | #include <net/inet_frag.h> | |
61 | #include <net/inet_ecn.h> | |
62 | ||
63 | static const char ip6_frag_cache_name[] = "ip6-frags"; | |
64 | ||
65 | struct ip6frag_skb_cb { | |
66 | struct inet6_skb_parm h; | |
67 | int offset; | |
68 | }; | |
69 | ||
70 | #define FRAG6_CB(skb) ((struct ip6frag_skb_cb *)((skb)->cb)) | |
71 | ||
72 | static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) | |
73 | { | |
74 | return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); | |
75 | } | |
76 | ||
77 | static struct inet_frags ip6_frags; | |
78 | ||
79 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, | |
80 | struct net_device *dev); | |
81 | ||
82 | /* | |
83 | * callers should be careful not to use the hash value outside the ipfrag_lock | |
84 | * as doing so could race with ipfrag_hash_rnd being recalculated. | |
85 | */ | |
86 | static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, | |
87 | const struct in6_addr *daddr) | |
88 | { | |
89 | net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); | |
90 | return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), | |
91 | (__force u32)id, ip6_frags.rnd); | |
92 | } | |
93 | ||
94 | static unsigned int ip6_hashfn(const struct inet_frag_queue *q) | |
95 | { | |
96 | const struct frag_queue *fq; | |
97 | ||
98 | fq = container_of(q, struct frag_queue, q); | |
99 | return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr); | |
100 | } | |
101 | ||
102 | bool ip6_frag_match(const struct inet_frag_queue *q, const void *a) | |
103 | { | |
104 | const struct frag_queue *fq; | |
105 | const struct ip6_create_arg *arg = a; | |
106 | ||
107 | fq = container_of(q, struct frag_queue, q); | |
108 | return fq->id == arg->id && | |
109 | fq->user == arg->user && | |
110 | ipv6_addr_equal(&fq->saddr, arg->src) && | |
111 | ipv6_addr_equal(&fq->daddr, arg->dst) && | |
112 | (arg->iif == fq->iif || | |
113 | !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST | | |
114 | IPV6_ADDR_LINKLOCAL))); | |
115 | } | |
116 | EXPORT_SYMBOL(ip6_frag_match); | |
117 | ||
118 | void ip6_frag_init(struct inet_frag_queue *q, const void *a) | |
119 | { | |
120 | struct frag_queue *fq = container_of(q, struct frag_queue, q); | |
121 | const struct ip6_create_arg *arg = a; | |
122 | ||
123 | fq->id = arg->id; | |
124 | fq->user = arg->user; | |
125 | fq->saddr = *arg->src; | |
126 | fq->daddr = *arg->dst; | |
127 | fq->ecn = arg->ecn; | |
128 | } | |
129 | EXPORT_SYMBOL(ip6_frag_init); | |
130 | ||
131 | void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, | |
132 | struct inet_frags *frags) | |
133 | { | |
134 | struct net_device *dev = NULL; | |
135 | ||
136 | spin_lock(&fq->q.lock); | |
137 | ||
138 | if (fq->q.flags & INET_FRAG_COMPLETE) | |
139 | goto out; | |
140 | ||
141 | inet_frag_kill(&fq->q, frags); | |
142 | ||
143 | rcu_read_lock(); | |
144 | dev = dev_get_by_index_rcu(net, fq->iif); | |
145 | if (!dev) | |
146 | goto out_rcu_unlock; | |
147 | ||
148 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
149 | ||
150 | if (inet_frag_evicting(&fq->q)) | |
151 | goto out_rcu_unlock; | |
152 | ||
153 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); | |
154 | ||
155 | /* Don't send error if the first segment did not arrive. */ | |
156 | if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments) | |
157 | goto out_rcu_unlock; | |
158 | ||
159 | /* But use as source device on which LAST ARRIVED | |
160 | * segment was received. And do not use fq->dev | |
161 | * pointer directly, device might already disappeared. | |
162 | */ | |
163 | fq->q.fragments->dev = dev; | |
164 | icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); | |
165 | out_rcu_unlock: | |
166 | rcu_read_unlock(); | |
167 | out: | |
168 | spin_unlock(&fq->q.lock); | |
169 | inet_frag_put(&fq->q, frags); | |
170 | } | |
171 | EXPORT_SYMBOL(ip6_expire_frag_queue); | |
172 | ||
173 | static void ip6_frag_expire(unsigned long data) | |
174 | { | |
175 | struct frag_queue *fq; | |
176 | struct net *net; | |
177 | ||
178 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); | |
179 | net = container_of(fq->q.net, struct net, ipv6.frags); | |
180 | ||
181 | ip6_expire_frag_queue(net, fq, &ip6_frags); | |
182 | } | |
183 | ||
184 | static struct frag_queue * | |
185 | fq_find(struct net *net, __be32 id, const struct in6_addr *src, | |
186 | const struct in6_addr *dst, int iif, u8 ecn) | |
187 | { | |
188 | struct inet_frag_queue *q; | |
189 | struct ip6_create_arg arg; | |
190 | unsigned int hash; | |
191 | ||
192 | arg.id = id; | |
193 | arg.user = IP6_DEFRAG_LOCAL_DELIVER; | |
194 | arg.src = src; | |
195 | arg.dst = dst; | |
196 | arg.iif = iif; | |
197 | arg.ecn = ecn; | |
198 | ||
199 | hash = inet6_hash_frag(id, src, dst); | |
200 | ||
201 | q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); | |
202 | if (IS_ERR_OR_NULL(q)) { | |
203 | inet_frag_maybe_warn_overflow(q, pr_fmt()); | |
204 | return NULL; | |
205 | } | |
206 | return container_of(q, struct frag_queue, q); | |
207 | } | |
208 | ||
209 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, | |
210 | struct frag_hdr *fhdr, int nhoff) | |
211 | { | |
212 | struct sk_buff *prev, *next; | |
213 | struct net_device *dev; | |
214 | int offset, end, fragsize; | |
215 | struct net *net = dev_net(skb_dst(skb)->dev); | |
216 | u8 ecn; | |
217 | ||
218 | if (fq->q.flags & INET_FRAG_COMPLETE) | |
219 | goto err; | |
220 | ||
221 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
222 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - | |
223 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
224 | ||
225 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
226 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
227 | IPSTATS_MIB_INHDRERRORS); | |
228 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, | |
229 | ((u8 *)&fhdr->frag_off - | |
230 | skb_network_header(skb))); | |
231 | return -1; | |
232 | } | |
233 | ||
234 | ecn = ip6_frag_ecn(ipv6_hdr(skb)); | |
235 | ||
236 | if (skb->ip_summed == CHECKSUM_COMPLETE) { | |
237 | const unsigned char *nh = skb_network_header(skb); | |
238 | skb->csum = csum_sub(skb->csum, | |
239 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, | |
240 | 0)); | |
241 | } | |
242 | ||
243 | /* Is this the final fragment? */ | |
244 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
245 | /* If we already have some bits beyond end | |
246 | * or have different end, the segment is corrupted. | |
247 | */ | |
248 | if (end < fq->q.len || | |
249 | ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) | |
250 | goto err; | |
251 | fq->q.flags |= INET_FRAG_LAST_IN; | |
252 | fq->q.len = end; | |
253 | } else { | |
254 | /* Check if the fragment is rounded to 8 bytes. | |
255 | * Required by the RFC. | |
256 | */ | |
257 | if (end & 0x7) { | |
258 | /* RFC2460 says always send parameter problem in | |
259 | * this case. -DaveM | |
260 | */ | |
261 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
262 | IPSTATS_MIB_INHDRERRORS); | |
263 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, | |
264 | offsetof(struct ipv6hdr, payload_len)); | |
265 | return -1; | |
266 | } | |
267 | if (end > fq->q.len) { | |
268 | /* Some bits beyond end -> corruption. */ | |
269 | if (fq->q.flags & INET_FRAG_LAST_IN) | |
270 | goto err; | |
271 | fq->q.len = end; | |
272 | } | |
273 | } | |
274 | ||
275 | if (end == offset) | |
276 | goto err; | |
277 | ||
278 | /* Point into the IP datagram 'data' part. */ | |
279 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
280 | goto err; | |
281 | ||
282 | if (pskb_trim_rcsum(skb, end - offset)) | |
283 | goto err; | |
284 | ||
285 | /* Find out which fragments are in front and at the back of us | |
286 | * in the chain of fragments so far. We must know where to put | |
287 | * this fragment, right? | |
288 | */ | |
289 | prev = fq->q.fragments_tail; | |
290 | if (!prev || FRAG6_CB(prev)->offset < offset) { | |
291 | next = NULL; | |
292 | goto found; | |
293 | } | |
294 | prev = NULL; | |
295 | for (next = fq->q.fragments; next != NULL; next = next->next) { | |
296 | if (FRAG6_CB(next)->offset >= offset) | |
297 | break; /* bingo! */ | |
298 | prev = next; | |
299 | } | |
300 | ||
301 | found: | |
302 | /* RFC5722, Section 4, amended by Errata ID : 3089 | |
303 | * When reassembling an IPv6 datagram, if | |
304 | * one or more its constituent fragments is determined to be an | |
305 | * overlapping fragment, the entire datagram (and any constituent | |
306 | * fragments) MUST be silently discarded. | |
307 | */ | |
308 | ||
309 | /* Check for overlap with preceding fragment. */ | |
310 | if (prev && | |
311 | (FRAG6_CB(prev)->offset + prev->len) > offset) | |
312 | goto discard_fq; | |
313 | ||
314 | /* Look for overlap with succeeding segment. */ | |
315 | if (next && FRAG6_CB(next)->offset < end) | |
316 | goto discard_fq; | |
317 | ||
318 | FRAG6_CB(skb)->offset = offset; | |
319 | ||
320 | /* Insert this fragment in the chain of fragments. */ | |
321 | skb->next = next; | |
322 | if (!next) | |
323 | fq->q.fragments_tail = skb; | |
324 | if (prev) | |
325 | prev->next = skb; | |
326 | else | |
327 | fq->q.fragments = skb; | |
328 | ||
329 | dev = skb->dev; | |
330 | if (dev) { | |
331 | fq->iif = dev->ifindex; | |
332 | skb->dev = NULL; | |
333 | } | |
334 | fq->q.stamp = skb->tstamp; | |
335 | fq->q.meat += skb->len; | |
336 | fq->ecn |= ecn; | |
337 | add_frag_mem_limit(fq->q.net, skb->truesize); | |
338 | ||
339 | fragsize = -skb_network_offset(skb) + skb->len; | |
340 | if (fragsize > fq->q.max_size) | |
341 | fq->q.max_size = fragsize; | |
342 | ||
343 | /* The first fragment. | |
344 | * nhoffset is obtained from the first fragment, of course. | |
345 | */ | |
346 | if (offset == 0) { | |
347 | fq->nhoffset = nhoff; | |
348 | fq->q.flags |= INET_FRAG_FIRST_IN; | |
349 | } | |
350 | ||
351 | if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && | |
352 | fq->q.meat == fq->q.len) { | |
353 | int res; | |
354 | unsigned long orefdst = skb->_skb_refdst; | |
355 | ||
356 | skb->_skb_refdst = 0UL; | |
357 | res = ip6_frag_reasm(fq, prev, dev); | |
358 | skb->_skb_refdst = orefdst; | |
359 | return res; | |
360 | } | |
361 | ||
362 | skb_dst_drop(skb); | |
363 | return -1; | |
364 | ||
365 | discard_fq: | |
366 | inet_frag_kill(&fq->q, &ip6_frags); | |
367 | err: | |
368 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
369 | IPSTATS_MIB_REASMFAILS); | |
370 | kfree_skb(skb); | |
371 | return -1; | |
372 | } | |
373 | ||
374 | /* | |
375 | * Check if this packet is complete. | |
376 | * Returns NULL on failure by any reason, and pointer | |
377 | * to current nexthdr field in reassembled frame. | |
378 | * | |
379 | * It is called with locked fq, and caller must check that | |
380 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
381 | * the last and the first frames arrived and all the bits are here. | |
382 | */ | |
383 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, | |
384 | struct net_device *dev) | |
385 | { | |
386 | struct net *net = container_of(fq->q.net, struct net, ipv6.frags); | |
387 | struct sk_buff *fp, *head = fq->q.fragments; | |
388 | int payload_len; | |
389 | unsigned int nhoff; | |
390 | int sum_truesize; | |
391 | u8 ecn; | |
392 | ||
393 | inet_frag_kill(&fq->q, &ip6_frags); | |
394 | ||
395 | ecn = ip_frag_ecn_table[fq->ecn]; | |
396 | if (unlikely(ecn == 0xff)) | |
397 | goto out_fail; | |
398 | ||
399 | /* Make the one we just received the head. */ | |
400 | if (prev) { | |
401 | head = prev->next; | |
402 | fp = skb_clone(head, GFP_ATOMIC); | |
403 | ||
404 | if (!fp) | |
405 | goto out_oom; | |
406 | ||
407 | fp->next = head->next; | |
408 | if (!fp->next) | |
409 | fq->q.fragments_tail = fp; | |
410 | prev->next = fp; | |
411 | ||
412 | skb_morph(head, fq->q.fragments); | |
413 | head->next = fq->q.fragments->next; | |
414 | ||
415 | consume_skb(fq->q.fragments); | |
416 | fq->q.fragments = head; | |
417 | } | |
418 | ||
419 | WARN_ON(head == NULL); | |
420 | WARN_ON(FRAG6_CB(head)->offset != 0); | |
421 | ||
422 | /* Unfragmented part is taken from the first segment. */ | |
423 | payload_len = ((head->data - skb_network_header(head)) - | |
424 | sizeof(struct ipv6hdr) + fq->q.len - | |
425 | sizeof(struct frag_hdr)); | |
426 | if (payload_len > IPV6_MAXPLEN) | |
427 | goto out_oversize; | |
428 | ||
429 | /* Head of list must not be cloned. */ | |
430 | if (skb_unclone(head, GFP_ATOMIC)) | |
431 | goto out_oom; | |
432 | ||
433 | /* If the first fragment is fragmented itself, we split | |
434 | * it to two chunks: the first with data and paged part | |
435 | * and the second, holding only fragments. */ | |
436 | if (skb_has_frag_list(head)) { | |
437 | struct sk_buff *clone; | |
438 | int i, plen = 0; | |
439 | ||
440 | clone = alloc_skb(0, GFP_ATOMIC); | |
441 | if (!clone) | |
442 | goto out_oom; | |
443 | clone->next = head->next; | |
444 | head->next = clone; | |
445 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
446 | skb_frag_list_init(head); | |
447 | for (i = 0; i < skb_shinfo(head)->nr_frags; i++) | |
448 | plen += skb_frag_size(&skb_shinfo(head)->frags[i]); | |
449 | clone->len = clone->data_len = head->data_len - plen; | |
450 | head->data_len -= clone->len; | |
451 | head->len -= clone->len; | |
452 | clone->csum = 0; | |
453 | clone->ip_summed = head->ip_summed; | |
454 | add_frag_mem_limit(fq->q.net, clone->truesize); | |
455 | } | |
456 | ||
457 | /* We have to remove fragment header from datagram and to relocate | |
458 | * header in order to calculate ICV correctly. */ | |
459 | nhoff = fq->nhoffset; | |
460 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; | |
461 | memmove(head->head + sizeof(struct frag_hdr), head->head, | |
462 | (head->data - head->head) - sizeof(struct frag_hdr)); | |
463 | if (skb_mac_header_was_set(head)) | |
464 | head->mac_header += sizeof(struct frag_hdr); | |
465 | head->network_header += sizeof(struct frag_hdr); | |
466 | ||
467 | skb_reset_transport_header(head); | |
468 | skb_push(head, head->data - skb_network_header(head)); | |
469 | ||
470 | sum_truesize = head->truesize; | |
471 | for (fp = head->next; fp;) { | |
472 | bool headstolen; | |
473 | int delta; | |
474 | struct sk_buff *next = fp->next; | |
475 | ||
476 | sum_truesize += fp->truesize; | |
477 | if (head->ip_summed != fp->ip_summed) | |
478 | head->ip_summed = CHECKSUM_NONE; | |
479 | else if (head->ip_summed == CHECKSUM_COMPLETE) | |
480 | head->csum = csum_add(head->csum, fp->csum); | |
481 | ||
482 | if (skb_try_coalesce(head, fp, &headstolen, &delta)) { | |
483 | kfree_skb_partial(fp, headstolen); | |
484 | } else { | |
485 | if (!skb_shinfo(head)->frag_list) | |
486 | skb_shinfo(head)->frag_list = fp; | |
487 | head->data_len += fp->len; | |
488 | head->len += fp->len; | |
489 | head->truesize += fp->truesize; | |
490 | } | |
491 | fp = next; | |
492 | } | |
493 | sub_frag_mem_limit(fq->q.net, sum_truesize); | |
494 | ||
495 | head->next = NULL; | |
496 | head->dev = dev; | |
497 | head->tstamp = fq->q.stamp; | |
498 | ipv6_hdr(head)->payload_len = htons(payload_len); | |
499 | ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); | |
500 | IP6CB(head)->nhoff = nhoff; | |
501 | IP6CB(head)->flags |= IP6SKB_FRAGMENTED; | |
502 | IP6CB(head)->frag_max_size = fq->q.max_size; | |
503 | ||
504 | /* Yes, and fold redundant checksum back. 8) */ | |
505 | skb_postpush_rcsum(head, skb_network_header(head), | |
506 | skb_network_header_len(head)); | |
507 | ||
508 | rcu_read_lock(); | |
509 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); | |
510 | rcu_read_unlock(); | |
511 | fq->q.fragments = NULL; | |
512 | fq->q.fragments_tail = NULL; | |
513 | return 1; | |
514 | ||
515 | out_oversize: | |
516 | net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); | |
517 | goto out_fail; | |
518 | out_oom: | |
519 | net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); | |
520 | out_fail: | |
521 | rcu_read_lock(); | |
522 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
523 | rcu_read_unlock(); | |
524 | return -1; | |
525 | } | |
526 | ||
527 | static int ipv6_frag_rcv(struct sk_buff *skb) | |
528 | { | |
529 | struct frag_hdr *fhdr; | |
530 | struct frag_queue *fq; | |
531 | const struct ipv6hdr *hdr = ipv6_hdr(skb); | |
532 | struct net *net = dev_net(skb_dst(skb)->dev); | |
533 | ||
534 | if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) | |
535 | goto fail_hdr; | |
536 | ||
537 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); | |
538 | ||
539 | /* Jumbo payload inhibits frag. header */ | |
540 | if (hdr->payload_len == 0) | |
541 | goto fail_hdr; | |
542 | ||
543 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + | |
544 | sizeof(struct frag_hdr)))) | |
545 | goto fail_hdr; | |
546 | ||
547 | hdr = ipv6_hdr(skb); | |
548 | fhdr = (struct frag_hdr *)skb_transport_header(skb); | |
549 | ||
550 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
551 | /* It is not a fragmented frame */ | |
552 | skb->transport_header += sizeof(struct frag_hdr); | |
553 | __IP6_INC_STATS(net, | |
554 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); | |
555 | ||
556 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); | |
557 | IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; | |
558 | return 1; | |
559 | } | |
560 | ||
561 | fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, | |
562 | skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); | |
563 | if (fq) { | |
564 | int ret; | |
565 | ||
566 | spin_lock(&fq->q.lock); | |
567 | ||
568 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); | |
569 | ||
570 | spin_unlock(&fq->q.lock); | |
571 | inet_frag_put(&fq->q, &ip6_frags); | |
572 | return ret; | |
573 | } | |
574 | ||
575 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); | |
576 | kfree_skb(skb); | |
577 | return -1; | |
578 | ||
579 | fail_hdr: | |
580 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), | |
581 | IPSTATS_MIB_INHDRERRORS); | |
582 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); | |
583 | return -1; | |
584 | } | |
585 | ||
586 | static const struct inet6_protocol frag_protocol = { | |
587 | .handler = ipv6_frag_rcv, | |
588 | .flags = INET6_PROTO_NOPOLICY, | |
589 | }; | |
590 | ||
591 | #ifdef CONFIG_SYSCTL | |
592 | static int zero; | |
593 | ||
594 | static struct ctl_table ip6_frags_ns_ctl_table[] = { | |
595 | { | |
596 | .procname = "ip6frag_high_thresh", | |
597 | .data = &init_net.ipv6.frags.high_thresh, | |
598 | .maxlen = sizeof(int), | |
599 | .mode = 0644, | |
600 | .proc_handler = proc_dointvec_minmax, | |
601 | .extra1 = &init_net.ipv6.frags.low_thresh | |
602 | }, | |
603 | { | |
604 | .procname = "ip6frag_low_thresh", | |
605 | .data = &init_net.ipv6.frags.low_thresh, | |
606 | .maxlen = sizeof(int), | |
607 | .mode = 0644, | |
608 | .proc_handler = proc_dointvec_minmax, | |
609 | .extra1 = &zero, | |
610 | .extra2 = &init_net.ipv6.frags.high_thresh | |
611 | }, | |
612 | { | |
613 | .procname = "ip6frag_time", | |
614 | .data = &init_net.ipv6.frags.timeout, | |
615 | .maxlen = sizeof(int), | |
616 | .mode = 0644, | |
617 | .proc_handler = proc_dointvec_jiffies, | |
618 | }, | |
619 | { } | |
620 | }; | |
621 | ||
622 | /* secret interval has been deprecated */ | |
623 | static int ip6_frags_secret_interval_unused; | |
624 | static struct ctl_table ip6_frags_ctl_table[] = { | |
625 | { | |
626 | .procname = "ip6frag_secret_interval", | |
627 | .data = &ip6_frags_secret_interval_unused, | |
628 | .maxlen = sizeof(int), | |
629 | .mode = 0644, | |
630 | .proc_handler = proc_dointvec_jiffies, | |
631 | }, | |
632 | { } | |
633 | }; | |
634 | ||
635 | static int __net_init ip6_frags_ns_sysctl_register(struct net *net) | |
636 | { | |
637 | struct ctl_table *table; | |
638 | struct ctl_table_header *hdr; | |
639 | ||
640 | table = ip6_frags_ns_ctl_table; | |
641 | if (!net_eq(net, &init_net)) { | |
642 | table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); | |
643 | if (!table) | |
644 | goto err_alloc; | |
645 | ||
646 | table[0].data = &net->ipv6.frags.high_thresh; | |
647 | table[0].extra1 = &net->ipv6.frags.low_thresh; | |
648 | table[0].extra2 = &init_net.ipv6.frags.high_thresh; | |
649 | table[1].data = &net->ipv6.frags.low_thresh; | |
650 | table[1].extra2 = &net->ipv6.frags.high_thresh; | |
651 | table[2].data = &net->ipv6.frags.timeout; | |
652 | ||
653 | /* Don't export sysctls to unprivileged users */ | |
654 | if (net->user_ns != &init_user_ns) | |
655 | table[0].procname = NULL; | |
656 | } | |
657 | ||
658 | hdr = register_net_sysctl(net, "net/ipv6", table); | |
659 | if (!hdr) | |
660 | goto err_reg; | |
661 | ||
662 | net->ipv6.sysctl.frags_hdr = hdr; | |
663 | return 0; | |
664 | ||
665 | err_reg: | |
666 | if (!net_eq(net, &init_net)) | |
667 | kfree(table); | |
668 | err_alloc: | |
669 | return -ENOMEM; | |
670 | } | |
671 | ||
672 | static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) | |
673 | { | |
674 | struct ctl_table *table; | |
675 | ||
676 | table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; | |
677 | unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); | |
678 | if (!net_eq(net, &init_net)) | |
679 | kfree(table); | |
680 | } | |
681 | ||
682 | static struct ctl_table_header *ip6_ctl_header; | |
683 | ||
684 | static int ip6_frags_sysctl_register(void) | |
685 | { | |
686 | ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", | |
687 | ip6_frags_ctl_table); | |
688 | return ip6_ctl_header == NULL ? -ENOMEM : 0; | |
689 | } | |
690 | ||
691 | static void ip6_frags_sysctl_unregister(void) | |
692 | { | |
693 | unregister_net_sysctl_table(ip6_ctl_header); | |
694 | } | |
695 | #else | |
696 | static int ip6_frags_ns_sysctl_register(struct net *net) | |
697 | { | |
698 | return 0; | |
699 | } | |
700 | ||
701 | static void ip6_frags_ns_sysctl_unregister(struct net *net) | |
702 | { | |
703 | } | |
704 | ||
705 | static int ip6_frags_sysctl_register(void) | |
706 | { | |
707 | return 0; | |
708 | } | |
709 | ||
710 | static void ip6_frags_sysctl_unregister(void) | |
711 | { | |
712 | } | |
713 | #endif | |
714 | ||
715 | static int __net_init ipv6_frags_init_net(struct net *net) | |
716 | { | |
717 | int res; | |
718 | ||
719 | net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; | |
720 | net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
721 | net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; | |
722 | ||
723 | res = inet_frags_init_net(&net->ipv6.frags); | |
724 | if (res) | |
725 | return res; | |
726 | res = ip6_frags_ns_sysctl_register(net); | |
727 | if (res) | |
728 | inet_frags_uninit_net(&net->ipv6.frags); | |
729 | return res; | |
730 | } | |
731 | ||
732 | static void __net_exit ipv6_frags_exit_net(struct net *net) | |
733 | { | |
734 | ip6_frags_ns_sysctl_unregister(net); | |
735 | inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); | |
736 | } | |
737 | ||
738 | static struct pernet_operations ip6_frags_ops = { | |
739 | .init = ipv6_frags_init_net, | |
740 | .exit = ipv6_frags_exit_net, | |
741 | }; | |
742 | ||
743 | int __init ipv6_frag_init(void) | |
744 | { | |
745 | int ret; | |
746 | ||
747 | ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); | |
748 | if (ret) | |
749 | goto out; | |
750 | ||
751 | ret = ip6_frags_sysctl_register(); | |
752 | if (ret) | |
753 | goto err_sysctl; | |
754 | ||
755 | ret = register_pernet_subsys(&ip6_frags_ops); | |
756 | if (ret) | |
757 | goto err_pernet; | |
758 | ||
759 | ip6_frags.hashfn = ip6_hashfn; | |
760 | ip6_frags.constructor = ip6_frag_init; | |
761 | ip6_frags.destructor = NULL; | |
762 | ip6_frags.qsize = sizeof(struct frag_queue); | |
763 | ip6_frags.match = ip6_frag_match; | |
764 | ip6_frags.frag_expire = ip6_frag_expire; | |
765 | ip6_frags.frags_cache_name = ip6_frag_cache_name; | |
766 | ret = inet_frags_init(&ip6_frags); | |
767 | if (ret) | |
768 | goto err_pernet; | |
769 | out: | |
770 | return ret; | |
771 | ||
772 | err_pernet: | |
773 | ip6_frags_sysctl_unregister(); | |
774 | err_sysctl: | |
775 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); | |
776 | goto out; | |
777 | } | |
778 | ||
779 | void ipv6_frag_exit(void) | |
780 | { | |
781 | inet_frags_fini(&ip6_frags); | |
782 | ip6_frags_sysctl_unregister(); | |
783 | unregister_pernet_subsys(&ip6_frags_ops); | |
784 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); | |
785 | } |