Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IPv6 fragment reassembly | |
1ab1457c | 3 | * Linux INET6 implementation |
1da177e4 LT |
4 | * |
5 | * Authors: | |
1ab1457c | 6 | * Pedro Roque <roque@di.fc.ul.pt> |
1da177e4 LT |
7 | * |
8 | * $Id: reassembly.c,v 1.26 2001/03/07 22:00:57 davem Exp $ | |
9 | * | |
10 | * Based on: net/ipv4/ip_fragment.c | |
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 | ||
1ab1457c YH |
18 | /* |
19 | * Fixes: | |
1da177e4 LT |
20 | * Andi Kleen Make it work with multiple hosts. |
21 | * More RFC compliance. | |
22 | * | |
23 | * Horst von Brand Add missing #include <linux/string.h> | |
24 | * Alexey Kuznetsov SMP races, threading, cleanup. | |
25 | * Patrick McHardy LRU queue of frag heads for evictor. | |
26 | * Mitsuru KANDA @USAGI Register inet6_protocol{}. | |
27 | * David Stevens and | |
28 | * YOSHIFUJI,H. @USAGI Always remove fragment header to | |
29 | * calculate ICV correctly. | |
30 | */ | |
1da177e4 LT |
31 | #include <linux/errno.h> |
32 | #include <linux/types.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/sockios.h> | |
36 | #include <linux/jiffies.h> | |
37 | #include <linux/net.h> | |
38 | #include <linux/list.h> | |
39 | #include <linux/netdevice.h> | |
40 | #include <linux/in6.h> | |
41 | #include <linux/ipv6.h> | |
42 | #include <linux/icmpv6.h> | |
43 | #include <linux/random.h> | |
44 | #include <linux/jhash.h> | |
f61944ef | 45 | #include <linux/skbuff.h> |
1da177e4 LT |
46 | |
47 | #include <net/sock.h> | |
48 | #include <net/snmp.h> | |
49 | ||
50 | #include <net/ipv6.h> | |
a11d206d | 51 | #include <net/ip6_route.h> |
1da177e4 LT |
52 | #include <net/protocol.h> |
53 | #include <net/transp_v6.h> | |
54 | #include <net/rawv6.h> | |
55 | #include <net/ndisc.h> | |
56 | #include <net/addrconf.h> | |
5ab11c98 | 57 | #include <net/inet_frag.h> |
1da177e4 | 58 | |
1da177e4 LT |
59 | struct ip6frag_skb_cb |
60 | { | |
61 | struct inet6_skb_parm h; | |
62 | int offset; | |
63 | }; | |
64 | ||
65 | #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) | |
66 | ||
67 | ||
68 | /* | |
69 | * Equivalent of ipv4 struct ipq | |
70 | */ | |
71 | ||
72 | struct frag_queue | |
73 | { | |
5ab11c98 | 74 | struct inet_frag_queue q; |
1da177e4 | 75 | |
e69a4adc | 76 | __be32 id; /* fragment id */ |
1da177e4 LT |
77 | struct in6_addr saddr; |
78 | struct in6_addr daddr; | |
79 | ||
1da177e4 | 80 | int iif; |
1da177e4 | 81 | unsigned int csum; |
1da177e4 | 82 | __u16 nhoffset; |
1da177e4 LT |
83 | }; |
84 | ||
7eb95156 | 85 | static struct inet_frags ip6_frags; |
1da177e4 | 86 | |
e5a2bb84 | 87 | int ip6_frag_nqueues(struct net *net) |
7eb95156 | 88 | { |
e5a2bb84 | 89 | return net->ipv6.frags.nqueues; |
7eb95156 | 90 | } |
1da177e4 | 91 | |
6ddc0822 | 92 | int ip6_frag_mem(struct net *net) |
7eb95156 | 93 | { |
6ddc0822 | 94 | return atomic_read(&net->ipv6.frags.mem); |
7eb95156 | 95 | } |
1da177e4 | 96 | |
f61944ef HX |
97 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
98 | struct net_device *dev); | |
99 | ||
f6596f9d ZB |
100 | /* |
101 | * callers should be careful not to use the hash value outside the ipfrag_lock | |
102 | * as doing so could race with ipfrag_hash_rnd being recalculated. | |
103 | */ | |
e69a4adc | 104 | static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr, |
1da177e4 LT |
105 | struct in6_addr *daddr) |
106 | { | |
107 | u32 a, b, c; | |
108 | ||
e69a4adc AV |
109 | a = (__force u32)saddr->s6_addr32[0]; |
110 | b = (__force u32)saddr->s6_addr32[1]; | |
111 | c = (__force u32)saddr->s6_addr32[2]; | |
1da177e4 LT |
112 | |
113 | a += JHASH_GOLDEN_RATIO; | |
114 | b += JHASH_GOLDEN_RATIO; | |
7eb95156 | 115 | c += ip6_frags.rnd; |
1da177e4 LT |
116 | __jhash_mix(a, b, c); |
117 | ||
e69a4adc AV |
118 | a += (__force u32)saddr->s6_addr32[3]; |
119 | b += (__force u32)daddr->s6_addr32[0]; | |
120 | c += (__force u32)daddr->s6_addr32[1]; | |
1da177e4 LT |
121 | __jhash_mix(a, b, c); |
122 | ||
e69a4adc AV |
123 | a += (__force u32)daddr->s6_addr32[2]; |
124 | b += (__force u32)daddr->s6_addr32[3]; | |
125 | c += (__force u32)id; | |
1da177e4 LT |
126 | __jhash_mix(a, b, c); |
127 | ||
7eb95156 | 128 | return c & (INETFRAGS_HASHSZ - 1); |
1da177e4 LT |
129 | } |
130 | ||
321a3a99 | 131 | static unsigned int ip6_hashfn(struct inet_frag_queue *q) |
1da177e4 | 132 | { |
321a3a99 | 133 | struct frag_queue *fq; |
1da177e4 | 134 | |
321a3a99 PE |
135 | fq = container_of(q, struct frag_queue, q); |
136 | return ip6qhashfn(fq->id, &fq->saddr, &fq->daddr); | |
1da177e4 LT |
137 | } |
138 | ||
abd6523d PE |
139 | int ip6_frag_match(struct inet_frag_queue *q, void *a) |
140 | { | |
141 | struct frag_queue *fq; | |
142 | struct ip6_create_arg *arg = a; | |
143 | ||
144 | fq = container_of(q, struct frag_queue, q); | |
145 | return (fq->id == arg->id && | |
146 | ipv6_addr_equal(&fq->saddr, arg->src) && | |
147 | ipv6_addr_equal(&fq->daddr, arg->dst)); | |
148 | } | |
149 | EXPORT_SYMBOL(ip6_frag_match); | |
150 | ||
1da177e4 | 151 | /* Memory Tracking Functions. */ |
6ddc0822 PE |
152 | static inline void frag_kfree_skb(struct netns_frags *nf, |
153 | struct sk_buff *skb, int *work) | |
1da177e4 LT |
154 | { |
155 | if (work) | |
156 | *work -= skb->truesize; | |
6ddc0822 | 157 | atomic_sub(skb->truesize, &nf->mem); |
1da177e4 LT |
158 | kfree_skb(skb); |
159 | } | |
160 | ||
c6fda282 | 161 | void ip6_frag_init(struct inet_frag_queue *q, void *a) |
1da177e4 | 162 | { |
c6fda282 PE |
163 | struct frag_queue *fq = container_of(q, struct frag_queue, q); |
164 | struct ip6_create_arg *arg = a; | |
165 | ||
166 | fq->id = arg->id; | |
167 | ipv6_addr_copy(&fq->saddr, arg->src); | |
168 | ipv6_addr_copy(&fq->daddr, arg->dst); | |
1da177e4 | 169 | } |
c6fda282 | 170 | EXPORT_SYMBOL(ip6_frag_init); |
1da177e4 | 171 | |
1da177e4 LT |
172 | /* Destruction primitives. */ |
173 | ||
4b6cb5d8 | 174 | static __inline__ void fq_put(struct frag_queue *fq) |
1da177e4 | 175 | { |
762cc408 | 176 | inet_frag_put(&fq->q, &ip6_frags); |
1da177e4 LT |
177 | } |
178 | ||
179 | /* Kill fq entry. It is not destroyed immediately, | |
180 | * because caller (and someone more) holds reference count. | |
181 | */ | |
182 | static __inline__ void fq_kill(struct frag_queue *fq) | |
183 | { | |
277e650d | 184 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 LT |
185 | } |
186 | ||
6ddc0822 | 187 | static void ip6_evictor(struct net *net, struct inet6_dev *idev) |
1da177e4 | 188 | { |
8e7999c4 PE |
189 | int evicted; |
190 | ||
6ddc0822 | 191 | evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags); |
8e7999c4 PE |
192 | if (evicted) |
193 | IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted); | |
1da177e4 LT |
194 | } |
195 | ||
196 | static void ip6_frag_expire(unsigned long data) | |
197 | { | |
e521db9d | 198 | struct frag_queue *fq; |
a11d206d | 199 | struct net_device *dev = NULL; |
1da177e4 | 200 | |
e521db9d PE |
201 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); |
202 | ||
5ab11c98 | 203 | spin_lock(&fq->q.lock); |
1da177e4 | 204 | |
5ab11c98 | 205 | if (fq->q.last_in & COMPLETE) |
1da177e4 LT |
206 | goto out; |
207 | ||
208 | fq_kill(fq); | |
209 | ||
881d966b | 210 | dev = dev_get_by_index(&init_net, fq->iif); |
a11d206d YH |
211 | if (!dev) |
212 | goto out; | |
213 | ||
214 | rcu_read_lock(); | |
215 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); | |
216 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
217 | rcu_read_unlock(); | |
1da177e4 | 218 | |
78c784c4 | 219 | /* Don't send error if the first segment did not arrive. */ |
5ab11c98 | 220 | if (!(fq->q.last_in&FIRST_IN) || !fq->q.fragments) |
78c784c4 IO |
221 | goto out; |
222 | ||
78c784c4 IO |
223 | /* |
224 | But use as source device on which LAST ARRIVED | |
225 | segment was received. And do not use fq->dev | |
226 | pointer directly, device might already disappeared. | |
227 | */ | |
5ab11c98 PE |
228 | fq->q.fragments->dev = dev; |
229 | icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev); | |
1da177e4 | 230 | out: |
a11d206d YH |
231 | if (dev) |
232 | dev_put(dev); | |
5ab11c98 | 233 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 234 | fq_put(fq); |
1da177e4 LT |
235 | } |
236 | ||
abd6523d | 237 | static __inline__ struct frag_queue * |
ac18e750 | 238 | fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst, |
abd6523d | 239 | struct inet6_dev *idev) |
1da177e4 | 240 | { |
c6fda282 PE |
241 | struct inet_frag_queue *q; |
242 | struct ip6_create_arg arg; | |
abd6523d | 243 | unsigned int hash; |
1da177e4 | 244 | |
c6fda282 PE |
245 | arg.id = id; |
246 | arg.src = src; | |
247 | arg.dst = dst; | |
abd6523d | 248 | hash = ip6qhashfn(id, src, dst); |
1da177e4 | 249 | |
ac18e750 | 250 | q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); |
c6fda282 PE |
251 | if (q == NULL) |
252 | goto oom; | |
1da177e4 | 253 | |
c6fda282 | 254 | return container_of(q, struct frag_queue, q); |
1da177e4 LT |
255 | |
256 | oom: | |
a11d206d | 257 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
258 | return NULL; |
259 | } | |
260 | ||
f61944ef | 261 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, |
1da177e4 LT |
262 | struct frag_hdr *fhdr, int nhoff) |
263 | { | |
264 | struct sk_buff *prev, *next; | |
f61944ef | 265 | struct net_device *dev; |
1da177e4 LT |
266 | int offset, end; |
267 | ||
5ab11c98 | 268 | if (fq->q.last_in & COMPLETE) |
1da177e4 LT |
269 | goto err; |
270 | ||
271 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
272 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
273 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
1da177e4 LT |
274 | |
275 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
a11d206d YH |
276 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
277 | IPSTATS_MIB_INHDRERRORS); | |
d56f90a7 ACM |
278 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
279 | ((u8 *)&fhdr->frag_off - | |
280 | skb_network_header(skb))); | |
f61944ef | 281 | return -1; |
1da177e4 LT |
282 | } |
283 | ||
d56f90a7 ACM |
284 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
285 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 286 | skb->csum = csum_sub(skb->csum, |
d56f90a7 ACM |
287 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
288 | 0)); | |
289 | } | |
1da177e4 LT |
290 | |
291 | /* Is this the final fragment? */ | |
292 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
293 | /* If we already have some bits beyond end | |
294 | * or have different end, the segment is corrupted. | |
295 | */ | |
5ab11c98 PE |
296 | if (end < fq->q.len || |
297 | ((fq->q.last_in & LAST_IN) && end != fq->q.len)) | |
1da177e4 | 298 | goto err; |
5ab11c98 PE |
299 | fq->q.last_in |= LAST_IN; |
300 | fq->q.len = end; | |
1da177e4 LT |
301 | } else { |
302 | /* Check if the fragment is rounded to 8 bytes. | |
303 | * Required by the RFC. | |
304 | */ | |
305 | if (end & 0x7) { | |
306 | /* RFC2460 says always send parameter problem in | |
307 | * this case. -DaveM | |
308 | */ | |
a11d206d YH |
309 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
310 | IPSTATS_MIB_INHDRERRORS); | |
1ab1457c | 311 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
1da177e4 | 312 | offsetof(struct ipv6hdr, payload_len)); |
f61944ef | 313 | return -1; |
1da177e4 | 314 | } |
5ab11c98 | 315 | if (end > fq->q.len) { |
1da177e4 | 316 | /* Some bits beyond end -> corruption. */ |
5ab11c98 | 317 | if (fq->q.last_in & LAST_IN) |
1da177e4 | 318 | goto err; |
5ab11c98 | 319 | fq->q.len = end; |
1da177e4 LT |
320 | } |
321 | } | |
322 | ||
323 | if (end == offset) | |
324 | goto err; | |
325 | ||
326 | /* Point into the IP datagram 'data' part. */ | |
327 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
328 | goto err; | |
1ab1457c | 329 | |
42ca89c1 SH |
330 | if (pskb_trim_rcsum(skb, end - offset)) |
331 | goto err; | |
1da177e4 LT |
332 | |
333 | /* Find out which fragments are in front and at the back of us | |
334 | * in the chain of fragments so far. We must know where to put | |
335 | * this fragment, right? | |
336 | */ | |
337 | prev = NULL; | |
5ab11c98 | 338 | for(next = fq->q.fragments; next != NULL; next = next->next) { |
1da177e4 LT |
339 | if (FRAG6_CB(next)->offset >= offset) |
340 | break; /* bingo! */ | |
341 | prev = next; | |
342 | } | |
343 | ||
344 | /* We found where to put this one. Check for overlap with | |
345 | * preceding fragment, and, if needed, align things so that | |
346 | * any overlaps are eliminated. | |
347 | */ | |
348 | if (prev) { | |
349 | int i = (FRAG6_CB(prev)->offset + prev->len) - offset; | |
350 | ||
351 | if (i > 0) { | |
352 | offset += i; | |
353 | if (end <= offset) | |
354 | goto err; | |
355 | if (!pskb_pull(skb, i)) | |
356 | goto err; | |
357 | if (skb->ip_summed != CHECKSUM_UNNECESSARY) | |
358 | skb->ip_summed = CHECKSUM_NONE; | |
359 | } | |
360 | } | |
361 | ||
362 | /* Look for overlap with succeeding segments. | |
363 | * If we can merge fragments, do it. | |
364 | */ | |
365 | while (next && FRAG6_CB(next)->offset < end) { | |
366 | int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */ | |
367 | ||
368 | if (i < next->len) { | |
369 | /* Eat head of the next overlapped fragment | |
370 | * and leave the loop. The next ones cannot overlap. | |
371 | */ | |
372 | if (!pskb_pull(next, i)) | |
373 | goto err; | |
374 | FRAG6_CB(next)->offset += i; /* next fragment */ | |
5ab11c98 | 375 | fq->q.meat -= i; |
1da177e4 LT |
376 | if (next->ip_summed != CHECKSUM_UNNECESSARY) |
377 | next->ip_summed = CHECKSUM_NONE; | |
378 | break; | |
379 | } else { | |
380 | struct sk_buff *free_it = next; | |
381 | ||
382 | /* Old fragment is completely overridden with | |
383 | * new one drop it. | |
384 | */ | |
385 | next = next->next; | |
386 | ||
387 | if (prev) | |
388 | prev->next = next; | |
389 | else | |
5ab11c98 | 390 | fq->q.fragments = next; |
1da177e4 | 391 | |
5ab11c98 | 392 | fq->q.meat -= free_it->len; |
6ddc0822 | 393 | frag_kfree_skb(fq->q.net, free_it, NULL); |
1da177e4 LT |
394 | } |
395 | } | |
396 | ||
397 | FRAG6_CB(skb)->offset = offset; | |
398 | ||
399 | /* Insert this fragment in the chain of fragments. */ | |
400 | skb->next = next; | |
401 | if (prev) | |
402 | prev->next = skb; | |
403 | else | |
5ab11c98 | 404 | fq->q.fragments = skb; |
1da177e4 | 405 | |
f61944ef HX |
406 | dev = skb->dev; |
407 | if (dev) { | |
408 | fq->iif = dev->ifindex; | |
409 | skb->dev = NULL; | |
410 | } | |
5ab11c98 PE |
411 | fq->q.stamp = skb->tstamp; |
412 | fq->q.meat += skb->len; | |
6ddc0822 | 413 | atomic_add(skb->truesize, &fq->q.net->mem); |
1da177e4 LT |
414 | |
415 | /* The first fragment. | |
416 | * nhoffset is obtained from the first fragment, of course. | |
417 | */ | |
418 | if (offset == 0) { | |
419 | fq->nhoffset = nhoff; | |
5ab11c98 | 420 | fq->q.last_in |= FIRST_IN; |
1da177e4 | 421 | } |
f61944ef | 422 | |
5ab11c98 | 423 | if (fq->q.last_in == (FIRST_IN | LAST_IN) && fq->q.meat == fq->q.len) |
f61944ef HX |
424 | return ip6_frag_reasm(fq, prev, dev); |
425 | ||
7eb95156 PE |
426 | write_lock(&ip6_frags.lock); |
427 | list_move_tail(&fq->q.lru_list, &ip6_frags.lru_list); | |
428 | write_unlock(&ip6_frags.lock); | |
f61944ef | 429 | return -1; |
1da177e4 LT |
430 | |
431 | err: | |
a11d206d | 432 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); |
1da177e4 | 433 | kfree_skb(skb); |
f61944ef | 434 | return -1; |
1da177e4 LT |
435 | } |
436 | ||
437 | /* | |
438 | * Check if this packet is complete. | |
439 | * Returns NULL on failure by any reason, and pointer | |
440 | * to current nexthdr field in reassembled frame. | |
441 | * | |
442 | * It is called with locked fq, and caller must check that | |
443 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
444 | * the last and the first frames arrived and all the bits are here. | |
445 | */ | |
f61944ef | 446 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
1da177e4 LT |
447 | struct net_device *dev) |
448 | { | |
5ab11c98 | 449 | struct sk_buff *fp, *head = fq->q.fragments; |
1da177e4 LT |
450 | int payload_len; |
451 | unsigned int nhoff; | |
452 | ||
453 | fq_kill(fq); | |
454 | ||
f61944ef HX |
455 | /* Make the one we just received the head. */ |
456 | if (prev) { | |
457 | head = prev->next; | |
458 | fp = skb_clone(head, GFP_ATOMIC); | |
459 | ||
460 | if (!fp) | |
461 | goto out_oom; | |
462 | ||
463 | fp->next = head->next; | |
464 | prev->next = fp; | |
465 | ||
5ab11c98 PE |
466 | skb_morph(head, fq->q.fragments); |
467 | head->next = fq->q.fragments->next; | |
f61944ef | 468 | |
5ab11c98 PE |
469 | kfree_skb(fq->q.fragments); |
470 | fq->q.fragments = head; | |
f61944ef HX |
471 | } |
472 | ||
1da177e4 LT |
473 | BUG_TRAP(head != NULL); |
474 | BUG_TRAP(FRAG6_CB(head)->offset == 0); | |
475 | ||
476 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 477 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 478 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 479 | sizeof(struct frag_hdr)); |
1da177e4 LT |
480 | if (payload_len > IPV6_MAXPLEN) |
481 | goto out_oversize; | |
482 | ||
483 | /* Head of list must not be cloned. */ | |
484 | if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) | |
485 | goto out_oom; | |
486 | ||
487 | /* If the first fragment is fragmented itself, we split | |
488 | * it to two chunks: the first with data and paged part | |
489 | * and the second, holding only fragments. */ | |
490 | if (skb_shinfo(head)->frag_list) { | |
491 | struct sk_buff *clone; | |
492 | int i, plen = 0; | |
493 | ||
494 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) | |
495 | goto out_oom; | |
496 | clone->next = head->next; | |
497 | head->next = clone; | |
498 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
499 | skb_shinfo(head)->frag_list = NULL; | |
500 | for (i=0; i<skb_shinfo(head)->nr_frags; i++) | |
501 | plen += skb_shinfo(head)->frags[i].size; | |
502 | clone->len = clone->data_len = head->data_len - plen; | |
503 | head->data_len -= clone->len; | |
504 | head->len -= clone->len; | |
505 | clone->csum = 0; | |
506 | clone->ip_summed = head->ip_summed; | |
6ddc0822 | 507 | atomic_add(clone->truesize, &fq->q.net->mem); |
1da177e4 LT |
508 | } |
509 | ||
510 | /* We have to remove fragment header from datagram and to relocate | |
511 | * header in order to calculate ICV correctly. */ | |
512 | nhoff = fq->nhoffset; | |
b0e380b1 | 513 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; |
1ab1457c | 514 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
1da177e4 | 515 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
516 | head->mac_header += sizeof(struct frag_hdr); |
517 | head->network_header += sizeof(struct frag_hdr); | |
1da177e4 LT |
518 | |
519 | skb_shinfo(head)->frag_list = head->next; | |
badff6d0 | 520 | skb_reset_transport_header(head); |
d56f90a7 | 521 | skb_push(head, head->data - skb_network_header(head)); |
6ddc0822 | 522 | atomic_sub(head->truesize, &fq->q.net->mem); |
1da177e4 LT |
523 | |
524 | for (fp=head->next; fp; fp = fp->next) { | |
525 | head->data_len += fp->len; | |
526 | head->len += fp->len; | |
527 | if (head->ip_summed != fp->ip_summed) | |
528 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 529 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 LT |
530 | head->csum = csum_add(head->csum, fp->csum); |
531 | head->truesize += fp->truesize; | |
6ddc0822 | 532 | atomic_sub(fp->truesize, &fq->q.net->mem); |
1da177e4 LT |
533 | } |
534 | ||
535 | head->next = NULL; | |
536 | head->dev = dev; | |
5ab11c98 | 537 | head->tstamp = fq->q.stamp; |
0660e03f | 538 | ipv6_hdr(head)->payload_len = htons(payload_len); |
951dbc8a | 539 | IP6CB(head)->nhoff = nhoff; |
1da177e4 | 540 | |
1da177e4 | 541 | /* Yes, and fold redundant checksum back. 8) */ |
84fa7933 | 542 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 543 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 544 | skb_network_header_len(head), |
d56f90a7 | 545 | head->csum); |
1da177e4 | 546 | |
a11d206d YH |
547 | rcu_read_lock(); |
548 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS); | |
549 | rcu_read_unlock(); | |
5ab11c98 | 550 | fq->q.fragments = NULL; |
1da177e4 LT |
551 | return 1; |
552 | ||
553 | out_oversize: | |
554 | if (net_ratelimit()) | |
555 | printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len); | |
556 | goto out_fail; | |
557 | out_oom: | |
558 | if (net_ratelimit()) | |
559 | printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n"); | |
560 | out_fail: | |
a11d206d YH |
561 | rcu_read_lock(); |
562 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
563 | rcu_read_unlock(); | |
1da177e4 LT |
564 | return -1; |
565 | } | |
566 | ||
e5bbef20 | 567 | static int ipv6_frag_rcv(struct sk_buff *skb) |
1da177e4 | 568 | { |
1da177e4 LT |
569 | struct frag_hdr *fhdr; |
570 | struct frag_queue *fq; | |
0660e03f | 571 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
ac18e750 | 572 | struct net *net; |
1da177e4 | 573 | |
a11d206d | 574 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS); |
1da177e4 LT |
575 | |
576 | /* Jumbo payload inhibits frag. header */ | |
577 | if (hdr->payload_len==0) { | |
a11d206d | 578 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
cfe1fc77 ACM |
579 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
580 | skb_network_header_len(skb)); | |
1da177e4 LT |
581 | return -1; |
582 | } | |
ea2ae17d ACM |
583 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + |
584 | sizeof(struct frag_hdr)))) { | |
a11d206d | 585 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
cfe1fc77 ACM |
586 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
587 | skb_network_header_len(skb)); | |
1da177e4 LT |
588 | return -1; |
589 | } | |
590 | ||
0660e03f | 591 | hdr = ipv6_hdr(skb); |
9c70220b | 592 | fhdr = (struct frag_hdr *)skb_transport_header(skb); |
1da177e4 LT |
593 | |
594 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
595 | /* It is not a fragmented frame */ | |
b0e380b1 | 596 | skb->transport_header += sizeof(struct frag_hdr); |
a11d206d | 597 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS); |
1da177e4 | 598 | |
d56f90a7 | 599 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); |
1da177e4 LT |
600 | return 1; |
601 | } | |
602 | ||
ac18e750 | 603 | net = skb->dev->nd_net; |
6ddc0822 PE |
604 | if (atomic_read(&net->ipv6.frags.mem) > |
605 | init_net.ipv6.sysctl.frags.high_thresh) | |
606 | ip6_evictor(net, ip6_dst_idev(skb->dst)); | |
1da177e4 | 607 | |
ac18e750 | 608 | if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, |
a11d206d | 609 | ip6_dst_idev(skb->dst))) != NULL) { |
f61944ef | 610 | int ret; |
1da177e4 | 611 | |
5ab11c98 | 612 | spin_lock(&fq->q.lock); |
1da177e4 | 613 | |
f61944ef | 614 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); |
1da177e4 | 615 | |
5ab11c98 | 616 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 617 | fq_put(fq); |
1da177e4 LT |
618 | return ret; |
619 | } | |
620 | ||
a11d206d | 621 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
622 | kfree_skb(skb); |
623 | return -1; | |
624 | } | |
625 | ||
626 | static struct inet6_protocol frag_protocol = | |
627 | { | |
628 | .handler = ipv6_frag_rcv, | |
629 | .flags = INET6_PROTO_NOPOLICY, | |
630 | }; | |
631 | ||
8d8354d2 PE |
632 | #ifdef CONFIG_SYSCTL |
633 | static struct ctl_table ip6_frags_ctl_table[] = { | |
634 | { | |
635 | .ctl_name = NET_IPV6_IP6FRAG_HIGH_THRESH, | |
636 | .procname = "ip6frag_high_thresh", | |
637 | .data = &init_net.ipv6.sysctl.frags.high_thresh, | |
638 | .maxlen = sizeof(int), | |
639 | .mode = 0644, | |
640 | .proc_handler = &proc_dointvec | |
641 | }, | |
642 | { | |
643 | .ctl_name = NET_IPV6_IP6FRAG_LOW_THRESH, | |
644 | .procname = "ip6frag_low_thresh", | |
645 | .data = &init_net.ipv6.sysctl.frags.low_thresh, | |
646 | .maxlen = sizeof(int), | |
647 | .mode = 0644, | |
648 | .proc_handler = &proc_dointvec | |
649 | }, | |
650 | { | |
651 | .ctl_name = NET_IPV6_IP6FRAG_TIME, | |
652 | .procname = "ip6frag_time", | |
b2fd5321 | 653 | .data = &init_net.ipv6.frags.timeout, |
8d8354d2 PE |
654 | .maxlen = sizeof(int), |
655 | .mode = 0644, | |
656 | .proc_handler = &proc_dointvec_jiffies, | |
657 | .strategy = &sysctl_jiffies, | |
658 | }, | |
659 | { | |
660 | .ctl_name = NET_IPV6_IP6FRAG_SECRET_INTERVAL, | |
661 | .procname = "ip6frag_secret_interval", | |
662 | .data = &init_net.ipv6.sysctl.frags.secret_interval, | |
663 | .maxlen = sizeof(int), | |
664 | .mode = 0644, | |
665 | .proc_handler = &proc_dointvec_jiffies, | |
666 | .strategy = &sysctl_jiffies | |
667 | }, | |
668 | { } | |
669 | }; | |
670 | ||
671 | static int ip6_frags_sysctl_register(struct net *net) | |
672 | { | |
e4a2d5c2 | 673 | struct ctl_table *table; |
8d8354d2 PE |
674 | struct ctl_table_header *hdr; |
675 | ||
e4a2d5c2 PE |
676 | table = ip6_frags_ctl_table; |
677 | if (net != &init_net) { | |
678 | table = kmemdup(table, sizeof(ip6_frags_ctl_table), GFP_KERNEL); | |
679 | if (table == NULL) | |
680 | goto err_alloc; | |
681 | ||
682 | table[0].mode &= ~0222; | |
683 | table[1].mode &= ~0222; | |
b2fd5321 | 684 | table[2].data = &net->ipv6.frags.timeout; |
e4a2d5c2 PE |
685 | table[3].mode &= ~0222; |
686 | } | |
687 | ||
688 | hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table); | |
689 | if (hdr == NULL) | |
690 | goto err_reg; | |
691 | ||
692 | net->ipv6.sysctl.frags_hdr = hdr; | |
693 | return 0; | |
694 | ||
695 | err_reg: | |
696 | if (net != &init_net) | |
697 | kfree(table); | |
698 | err_alloc: | |
699 | return -ENOMEM; | |
700 | } | |
701 | ||
702 | static void ip6_frags_sysctl_unregister(struct net *net) | |
703 | { | |
704 | struct ctl_table *table; | |
705 | ||
706 | table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; | |
707 | unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); | |
708 | kfree(table); | |
8d8354d2 PE |
709 | } |
710 | #else | |
711 | static inline int ip6_frags_sysctl_register(struct net *net) | |
e71e0349 | 712 | { |
8d8354d2 PE |
713 | return 0; |
714 | } | |
e4a2d5c2 PE |
715 | |
716 | static inline void ip6_frags_sysctl_unregister(struct net *net) | |
717 | { | |
718 | } | |
8d8354d2 | 719 | #endif |
7d460db9 | 720 | |
8d8354d2 PE |
721 | static int ipv6_frags_init_net(struct net *net) |
722 | { | |
e71e0349 | 723 | ip6_frags.ctl = &net->ipv6.sysctl.frags; |
8d8354d2 PE |
724 | |
725 | net->ipv6.sysctl.frags.high_thresh = 256 * 1024; | |
726 | net->ipv6.sysctl.frags.low_thresh = 192 * 1024; | |
b2fd5321 | 727 | net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; |
8d8354d2 PE |
728 | net->ipv6.sysctl.frags.secret_interval = 10 * 60 * HZ; |
729 | ||
e5a2bb84 PE |
730 | inet_frags_init_net(&net->ipv6.frags); |
731 | ||
8d8354d2 | 732 | return ip6_frags_sysctl_register(net); |
e71e0349 DL |
733 | } |
734 | ||
853cbbaa | 735 | int __init ipv6_frag_init(void) |
1da177e4 | 736 | { |
853cbbaa | 737 | int ret; |
1da177e4 | 738 | |
853cbbaa DL |
739 | ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
740 | if (ret) | |
741 | goto out; | |
e71e0349 | 742 | |
8d8354d2 PE |
743 | ipv6_frags_init_net(&init_net); |
744 | ||
321a3a99 | 745 | ip6_frags.hashfn = ip6_hashfn; |
c6fda282 | 746 | ip6_frags.constructor = ip6_frag_init; |
c9547709 | 747 | ip6_frags.destructor = NULL; |
1e4b8287 PE |
748 | ip6_frags.skb_free = NULL; |
749 | ip6_frags.qsize = sizeof(struct frag_queue); | |
abd6523d | 750 | ip6_frags.match = ip6_frag_match; |
e521db9d | 751 | ip6_frags.frag_expire = ip6_frag_expire; |
7eb95156 | 752 | inet_frags_init(&ip6_frags); |
853cbbaa DL |
753 | out: |
754 | return ret; | |
755 | } | |
756 | ||
757 | void ipv6_frag_exit(void) | |
758 | { | |
759 | inet_frags_fini(&ip6_frags); | |
760 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); | |
1da177e4 | 761 | } |