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Commit | Line | Data |
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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 | ||
04128f23 PE |
85 | struct inet_frags_ctl ip6_frags_ctl __read_mostly = { |
86 | .high_thresh = 256 * 1024, | |
87 | .low_thresh = 192 * 1024, | |
88 | .timeout = IPV6_FRAG_TIMEOUT, | |
89 | .secret_interval = 10 * 60 * HZ, | |
90 | }; | |
91 | ||
7eb95156 | 92 | static struct inet_frags ip6_frags; |
1da177e4 | 93 | |
7eb95156 PE |
94 | int ip6_frag_nqueues(void) |
95 | { | |
96 | return ip6_frags.nqueues; | |
97 | } | |
1da177e4 | 98 | |
7eb95156 PE |
99 | int ip6_frag_mem(void) |
100 | { | |
101 | return atomic_read(&ip6_frags.mem); | |
102 | } | |
1da177e4 | 103 | |
f61944ef HX |
104 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
105 | struct net_device *dev); | |
106 | ||
f6596f9d ZB |
107 | /* |
108 | * callers should be careful not to use the hash value outside the ipfrag_lock | |
109 | * as doing so could race with ipfrag_hash_rnd being recalculated. | |
110 | */ | |
e69a4adc | 111 | static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr, |
1da177e4 LT |
112 | struct in6_addr *daddr) |
113 | { | |
114 | u32 a, b, c; | |
115 | ||
e69a4adc AV |
116 | a = (__force u32)saddr->s6_addr32[0]; |
117 | b = (__force u32)saddr->s6_addr32[1]; | |
118 | c = (__force u32)saddr->s6_addr32[2]; | |
1da177e4 LT |
119 | |
120 | a += JHASH_GOLDEN_RATIO; | |
121 | b += JHASH_GOLDEN_RATIO; | |
7eb95156 | 122 | c += ip6_frags.rnd; |
1da177e4 LT |
123 | __jhash_mix(a, b, c); |
124 | ||
e69a4adc AV |
125 | a += (__force u32)saddr->s6_addr32[3]; |
126 | b += (__force u32)daddr->s6_addr32[0]; | |
127 | c += (__force u32)daddr->s6_addr32[1]; | |
1da177e4 LT |
128 | __jhash_mix(a, b, c); |
129 | ||
e69a4adc AV |
130 | a += (__force u32)daddr->s6_addr32[2]; |
131 | b += (__force u32)daddr->s6_addr32[3]; | |
132 | c += (__force u32)id; | |
1da177e4 LT |
133 | __jhash_mix(a, b, c); |
134 | ||
7eb95156 | 135 | return c & (INETFRAGS_HASHSZ - 1); |
1da177e4 LT |
136 | } |
137 | ||
321a3a99 | 138 | static unsigned int ip6_hashfn(struct inet_frag_queue *q) |
1da177e4 | 139 | { |
321a3a99 | 140 | struct frag_queue *fq; |
1da177e4 | 141 | |
321a3a99 PE |
142 | fq = container_of(q, struct frag_queue, q); |
143 | return ip6qhashfn(fq->id, &fq->saddr, &fq->daddr); | |
1da177e4 LT |
144 | } |
145 | ||
2588fe1d PE |
146 | int ip6_frag_equal(struct inet_frag_queue *q1, struct inet_frag_queue *q2) |
147 | { | |
148 | struct frag_queue *fq1, *fq2; | |
149 | ||
150 | fq1 = container_of(q1, struct frag_queue, q); | |
151 | fq2 = container_of(q2, struct frag_queue, q); | |
152 | return (fq1->id == fq2->id && | |
153 | ipv6_addr_equal(&fq2->saddr, &fq1->saddr) && | |
154 | ipv6_addr_equal(&fq2->daddr, &fq1->daddr)); | |
155 | } | |
156 | EXPORT_SYMBOL(ip6_frag_equal); | |
157 | ||
1da177e4 LT |
158 | /* Memory Tracking Functions. */ |
159 | static inline void frag_kfree_skb(struct sk_buff *skb, int *work) | |
160 | { | |
161 | if (work) | |
162 | *work -= skb->truesize; | |
7eb95156 | 163 | atomic_sub(skb->truesize, &ip6_frags.mem); |
1da177e4 LT |
164 | kfree_skb(skb); |
165 | } | |
166 | ||
1e4b8287 | 167 | static void ip6_frag_free(struct inet_frag_queue *fq) |
1da177e4 | 168 | { |
1e4b8287 | 169 | kfree(container_of(fq, struct frag_queue, q)); |
1da177e4 LT |
170 | } |
171 | ||
172 | static inline struct frag_queue *frag_alloc_queue(void) | |
173 | { | |
e521db9d | 174 | struct inet_frag_queue *q; |
1da177e4 | 175 | |
e521db9d PE |
176 | q = inet_frag_alloc(&ip6_frags); |
177 | return q ? container_of(q, struct frag_queue, q) : NULL; | |
1da177e4 LT |
178 | } |
179 | ||
180 | /* Destruction primitives. */ | |
181 | ||
4b6cb5d8 | 182 | static __inline__ void fq_put(struct frag_queue *fq) |
1da177e4 | 183 | { |
762cc408 | 184 | inet_frag_put(&fq->q, &ip6_frags); |
1da177e4 LT |
185 | } |
186 | ||
187 | /* Kill fq entry. It is not destroyed immediately, | |
188 | * because caller (and someone more) holds reference count. | |
189 | */ | |
190 | static __inline__ void fq_kill(struct frag_queue *fq) | |
191 | { | |
277e650d | 192 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 LT |
193 | } |
194 | ||
a11d206d | 195 | static void ip6_evictor(struct inet6_dev *idev) |
1da177e4 | 196 | { |
8e7999c4 PE |
197 | int evicted; |
198 | ||
199 | evicted = inet_frag_evictor(&ip6_frags); | |
200 | if (evicted) | |
201 | IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted); | |
1da177e4 LT |
202 | } |
203 | ||
204 | static void ip6_frag_expire(unsigned long data) | |
205 | { | |
e521db9d | 206 | struct frag_queue *fq; |
a11d206d | 207 | struct net_device *dev = NULL; |
1da177e4 | 208 | |
e521db9d PE |
209 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); |
210 | ||
5ab11c98 | 211 | spin_lock(&fq->q.lock); |
1da177e4 | 212 | |
5ab11c98 | 213 | if (fq->q.last_in & COMPLETE) |
1da177e4 LT |
214 | goto out; |
215 | ||
216 | fq_kill(fq); | |
217 | ||
881d966b | 218 | dev = dev_get_by_index(&init_net, fq->iif); |
a11d206d YH |
219 | if (!dev) |
220 | goto out; | |
221 | ||
222 | rcu_read_lock(); | |
223 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); | |
224 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
225 | rcu_read_unlock(); | |
1da177e4 | 226 | |
78c784c4 | 227 | /* Don't send error if the first segment did not arrive. */ |
5ab11c98 | 228 | if (!(fq->q.last_in&FIRST_IN) || !fq->q.fragments) |
78c784c4 IO |
229 | goto out; |
230 | ||
78c784c4 IO |
231 | /* |
232 | But use as source device on which LAST ARRIVED | |
233 | segment was received. And do not use fq->dev | |
234 | pointer directly, device might already disappeared. | |
235 | */ | |
5ab11c98 PE |
236 | fq->q.fragments->dev = dev; |
237 | icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev); | |
1da177e4 | 238 | out: |
a11d206d YH |
239 | if (dev) |
240 | dev_put(dev); | |
5ab11c98 | 241 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 242 | fq_put(fq); |
1da177e4 LT |
243 | } |
244 | ||
245 | /* Creation primitives. */ | |
246 | ||
247 | ||
fd9e6354 PE |
248 | static struct frag_queue *ip6_frag_intern(struct frag_queue *fq_in, |
249 | unsigned int hash) | |
1da177e4 | 250 | { |
2588fe1d | 251 | struct inet_frag_queue *q; |
1da177e4 | 252 | |
2588fe1d PE |
253 | q = inet_frag_intern(&fq_in->q, &ip6_frags, hash); |
254 | return container_of(q, struct frag_queue, q); | |
1da177e4 LT |
255 | } |
256 | ||
257 | ||
258 | static struct frag_queue * | |
e69a4adc | 259 | ip6_frag_create(__be32 id, struct in6_addr *src, struct in6_addr *dst, |
fd9e6354 | 260 | struct inet6_dev *idev, unsigned int hash) |
1da177e4 LT |
261 | { |
262 | struct frag_queue *fq; | |
263 | ||
264 | if ((fq = frag_alloc_queue()) == NULL) | |
265 | goto oom; | |
266 | ||
1da177e4 LT |
267 | fq->id = id; |
268 | ipv6_addr_copy(&fq->saddr, src); | |
269 | ipv6_addr_copy(&fq->daddr, dst); | |
270 | ||
fd9e6354 | 271 | return ip6_frag_intern(fq, hash); |
1da177e4 LT |
272 | |
273 | oom: | |
a11d206d | 274 | IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
275 | return NULL; |
276 | } | |
277 | ||
278 | static __inline__ struct frag_queue * | |
e69a4adc | 279 | fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst, |
a11d206d | 280 | struct inet6_dev *idev) |
1da177e4 LT |
281 | { |
282 | struct frag_queue *fq; | |
e7c8a41e | 283 | struct hlist_node *n; |
f6596f9d | 284 | unsigned int hash; |
1da177e4 | 285 | |
7eb95156 | 286 | read_lock(&ip6_frags.lock); |
f6596f9d | 287 | hash = ip6qhashfn(id, src, dst); |
7eb95156 | 288 | hlist_for_each_entry(fq, n, &ip6_frags.hash[hash], q.list) { |
1ab1457c | 289 | if (fq->id == id && |
1da177e4 LT |
290 | ipv6_addr_equal(src, &fq->saddr) && |
291 | ipv6_addr_equal(dst, &fq->daddr)) { | |
5ab11c98 | 292 | atomic_inc(&fq->q.refcnt); |
7eb95156 | 293 | read_unlock(&ip6_frags.lock); |
1da177e4 LT |
294 | return fq; |
295 | } | |
296 | } | |
7eb95156 | 297 | read_unlock(&ip6_frags.lock); |
1da177e4 | 298 | |
fd9e6354 | 299 | return ip6_frag_create(id, src, dst, idev, hash); |
1da177e4 LT |
300 | } |
301 | ||
302 | ||
f61944ef | 303 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, |
1da177e4 LT |
304 | struct frag_hdr *fhdr, int nhoff) |
305 | { | |
306 | struct sk_buff *prev, *next; | |
f61944ef | 307 | struct net_device *dev; |
1da177e4 LT |
308 | int offset, end; |
309 | ||
5ab11c98 | 310 | if (fq->q.last_in & COMPLETE) |
1da177e4 LT |
311 | goto err; |
312 | ||
313 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
314 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
315 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
1da177e4 LT |
316 | |
317 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
a11d206d YH |
318 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
319 | IPSTATS_MIB_INHDRERRORS); | |
d56f90a7 ACM |
320 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
321 | ((u8 *)&fhdr->frag_off - | |
322 | skb_network_header(skb))); | |
f61944ef | 323 | return -1; |
1da177e4 LT |
324 | } |
325 | ||
d56f90a7 ACM |
326 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
327 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 328 | skb->csum = csum_sub(skb->csum, |
d56f90a7 ACM |
329 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
330 | 0)); | |
331 | } | |
1da177e4 LT |
332 | |
333 | /* Is this the final fragment? */ | |
334 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
335 | /* If we already have some bits beyond end | |
336 | * or have different end, the segment is corrupted. | |
337 | */ | |
5ab11c98 PE |
338 | if (end < fq->q.len || |
339 | ((fq->q.last_in & LAST_IN) && end != fq->q.len)) | |
1da177e4 | 340 | goto err; |
5ab11c98 PE |
341 | fq->q.last_in |= LAST_IN; |
342 | fq->q.len = end; | |
1da177e4 LT |
343 | } else { |
344 | /* Check if the fragment is rounded to 8 bytes. | |
345 | * Required by the RFC. | |
346 | */ | |
347 | if (end & 0x7) { | |
348 | /* RFC2460 says always send parameter problem in | |
349 | * this case. -DaveM | |
350 | */ | |
a11d206d YH |
351 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
352 | IPSTATS_MIB_INHDRERRORS); | |
1ab1457c | 353 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
1da177e4 | 354 | offsetof(struct ipv6hdr, payload_len)); |
f61944ef | 355 | return -1; |
1da177e4 | 356 | } |
5ab11c98 | 357 | if (end > fq->q.len) { |
1da177e4 | 358 | /* Some bits beyond end -> corruption. */ |
5ab11c98 | 359 | if (fq->q.last_in & LAST_IN) |
1da177e4 | 360 | goto err; |
5ab11c98 | 361 | fq->q.len = end; |
1da177e4 LT |
362 | } |
363 | } | |
364 | ||
365 | if (end == offset) | |
366 | goto err; | |
367 | ||
368 | /* Point into the IP datagram 'data' part. */ | |
369 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
370 | goto err; | |
1ab1457c | 371 | |
42ca89c1 SH |
372 | if (pskb_trim_rcsum(skb, end - offset)) |
373 | goto err; | |
1da177e4 LT |
374 | |
375 | /* Find out which fragments are in front and at the back of us | |
376 | * in the chain of fragments so far. We must know where to put | |
377 | * this fragment, right? | |
378 | */ | |
379 | prev = NULL; | |
5ab11c98 | 380 | for(next = fq->q.fragments; next != NULL; next = next->next) { |
1da177e4 LT |
381 | if (FRAG6_CB(next)->offset >= offset) |
382 | break; /* bingo! */ | |
383 | prev = next; | |
384 | } | |
385 | ||
386 | /* We found where to put this one. Check for overlap with | |
387 | * preceding fragment, and, if needed, align things so that | |
388 | * any overlaps are eliminated. | |
389 | */ | |
390 | if (prev) { | |
391 | int i = (FRAG6_CB(prev)->offset + prev->len) - offset; | |
392 | ||
393 | if (i > 0) { | |
394 | offset += i; | |
395 | if (end <= offset) | |
396 | goto err; | |
397 | if (!pskb_pull(skb, i)) | |
398 | goto err; | |
399 | if (skb->ip_summed != CHECKSUM_UNNECESSARY) | |
400 | skb->ip_summed = CHECKSUM_NONE; | |
401 | } | |
402 | } | |
403 | ||
404 | /* Look for overlap with succeeding segments. | |
405 | * If we can merge fragments, do it. | |
406 | */ | |
407 | while (next && FRAG6_CB(next)->offset < end) { | |
408 | int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */ | |
409 | ||
410 | if (i < next->len) { | |
411 | /* Eat head of the next overlapped fragment | |
412 | * and leave the loop. The next ones cannot overlap. | |
413 | */ | |
414 | if (!pskb_pull(next, i)) | |
415 | goto err; | |
416 | FRAG6_CB(next)->offset += i; /* next fragment */ | |
5ab11c98 | 417 | fq->q.meat -= i; |
1da177e4 LT |
418 | if (next->ip_summed != CHECKSUM_UNNECESSARY) |
419 | next->ip_summed = CHECKSUM_NONE; | |
420 | break; | |
421 | } else { | |
422 | struct sk_buff *free_it = next; | |
423 | ||
424 | /* Old fragment is completely overridden with | |
425 | * new one drop it. | |
426 | */ | |
427 | next = next->next; | |
428 | ||
429 | if (prev) | |
430 | prev->next = next; | |
431 | else | |
5ab11c98 | 432 | fq->q.fragments = next; |
1da177e4 | 433 | |
5ab11c98 | 434 | fq->q.meat -= free_it->len; |
1da177e4 LT |
435 | frag_kfree_skb(free_it, NULL); |
436 | } | |
437 | } | |
438 | ||
439 | FRAG6_CB(skb)->offset = offset; | |
440 | ||
441 | /* Insert this fragment in the chain of fragments. */ | |
442 | skb->next = next; | |
443 | if (prev) | |
444 | prev->next = skb; | |
445 | else | |
5ab11c98 | 446 | fq->q.fragments = skb; |
1da177e4 | 447 | |
f61944ef HX |
448 | dev = skb->dev; |
449 | if (dev) { | |
450 | fq->iif = dev->ifindex; | |
451 | skb->dev = NULL; | |
452 | } | |
5ab11c98 PE |
453 | fq->q.stamp = skb->tstamp; |
454 | fq->q.meat += skb->len; | |
7eb95156 | 455 | atomic_add(skb->truesize, &ip6_frags.mem); |
1da177e4 LT |
456 | |
457 | /* The first fragment. | |
458 | * nhoffset is obtained from the first fragment, of course. | |
459 | */ | |
460 | if (offset == 0) { | |
461 | fq->nhoffset = nhoff; | |
5ab11c98 | 462 | fq->q.last_in |= FIRST_IN; |
1da177e4 | 463 | } |
f61944ef | 464 | |
5ab11c98 | 465 | if (fq->q.last_in == (FIRST_IN | LAST_IN) && fq->q.meat == fq->q.len) |
f61944ef HX |
466 | return ip6_frag_reasm(fq, prev, dev); |
467 | ||
7eb95156 PE |
468 | write_lock(&ip6_frags.lock); |
469 | list_move_tail(&fq->q.lru_list, &ip6_frags.lru_list); | |
470 | write_unlock(&ip6_frags.lock); | |
f61944ef | 471 | return -1; |
1da177e4 LT |
472 | |
473 | err: | |
a11d206d | 474 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); |
1da177e4 | 475 | kfree_skb(skb); |
f61944ef | 476 | return -1; |
1da177e4 LT |
477 | } |
478 | ||
479 | /* | |
480 | * Check if this packet is complete. | |
481 | * Returns NULL on failure by any reason, and pointer | |
482 | * to current nexthdr field in reassembled frame. | |
483 | * | |
484 | * It is called with locked fq, and caller must check that | |
485 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
486 | * the last and the first frames arrived and all the bits are here. | |
487 | */ | |
f61944ef | 488 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
1da177e4 LT |
489 | struct net_device *dev) |
490 | { | |
5ab11c98 | 491 | struct sk_buff *fp, *head = fq->q.fragments; |
1da177e4 LT |
492 | int payload_len; |
493 | unsigned int nhoff; | |
494 | ||
495 | fq_kill(fq); | |
496 | ||
f61944ef HX |
497 | /* Make the one we just received the head. */ |
498 | if (prev) { | |
499 | head = prev->next; | |
500 | fp = skb_clone(head, GFP_ATOMIC); | |
501 | ||
502 | if (!fp) | |
503 | goto out_oom; | |
504 | ||
505 | fp->next = head->next; | |
506 | prev->next = fp; | |
507 | ||
5ab11c98 PE |
508 | skb_morph(head, fq->q.fragments); |
509 | head->next = fq->q.fragments->next; | |
f61944ef | 510 | |
5ab11c98 PE |
511 | kfree_skb(fq->q.fragments); |
512 | fq->q.fragments = head; | |
f61944ef HX |
513 | } |
514 | ||
1da177e4 LT |
515 | BUG_TRAP(head != NULL); |
516 | BUG_TRAP(FRAG6_CB(head)->offset == 0); | |
517 | ||
518 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 519 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 520 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 521 | sizeof(struct frag_hdr)); |
1da177e4 LT |
522 | if (payload_len > IPV6_MAXPLEN) |
523 | goto out_oversize; | |
524 | ||
525 | /* Head of list must not be cloned. */ | |
526 | if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) | |
527 | goto out_oom; | |
528 | ||
529 | /* If the first fragment is fragmented itself, we split | |
530 | * it to two chunks: the first with data and paged part | |
531 | * and the second, holding only fragments. */ | |
532 | if (skb_shinfo(head)->frag_list) { | |
533 | struct sk_buff *clone; | |
534 | int i, plen = 0; | |
535 | ||
536 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) | |
537 | goto out_oom; | |
538 | clone->next = head->next; | |
539 | head->next = clone; | |
540 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
541 | skb_shinfo(head)->frag_list = NULL; | |
542 | for (i=0; i<skb_shinfo(head)->nr_frags; i++) | |
543 | plen += skb_shinfo(head)->frags[i].size; | |
544 | clone->len = clone->data_len = head->data_len - plen; | |
545 | head->data_len -= clone->len; | |
546 | head->len -= clone->len; | |
547 | clone->csum = 0; | |
548 | clone->ip_summed = head->ip_summed; | |
7eb95156 | 549 | atomic_add(clone->truesize, &ip6_frags.mem); |
1da177e4 LT |
550 | } |
551 | ||
552 | /* We have to remove fragment header from datagram and to relocate | |
553 | * header in order to calculate ICV correctly. */ | |
554 | nhoff = fq->nhoffset; | |
b0e380b1 | 555 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; |
1ab1457c | 556 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
1da177e4 | 557 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
558 | head->mac_header += sizeof(struct frag_hdr); |
559 | head->network_header += sizeof(struct frag_hdr); | |
1da177e4 LT |
560 | |
561 | skb_shinfo(head)->frag_list = head->next; | |
badff6d0 | 562 | skb_reset_transport_header(head); |
d56f90a7 | 563 | skb_push(head, head->data - skb_network_header(head)); |
7eb95156 | 564 | atomic_sub(head->truesize, &ip6_frags.mem); |
1da177e4 LT |
565 | |
566 | for (fp=head->next; fp; fp = fp->next) { | |
567 | head->data_len += fp->len; | |
568 | head->len += fp->len; | |
569 | if (head->ip_summed != fp->ip_summed) | |
570 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 571 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 LT |
572 | head->csum = csum_add(head->csum, fp->csum); |
573 | head->truesize += fp->truesize; | |
7eb95156 | 574 | atomic_sub(fp->truesize, &ip6_frags.mem); |
1da177e4 LT |
575 | } |
576 | ||
577 | head->next = NULL; | |
578 | head->dev = dev; | |
5ab11c98 | 579 | head->tstamp = fq->q.stamp; |
0660e03f | 580 | ipv6_hdr(head)->payload_len = htons(payload_len); |
951dbc8a | 581 | IP6CB(head)->nhoff = nhoff; |
1da177e4 | 582 | |
1da177e4 | 583 | /* Yes, and fold redundant checksum back. 8) */ |
84fa7933 | 584 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 585 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 586 | skb_network_header_len(head), |
d56f90a7 | 587 | head->csum); |
1da177e4 | 588 | |
a11d206d YH |
589 | rcu_read_lock(); |
590 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS); | |
591 | rcu_read_unlock(); | |
5ab11c98 | 592 | fq->q.fragments = NULL; |
1da177e4 LT |
593 | return 1; |
594 | ||
595 | out_oversize: | |
596 | if (net_ratelimit()) | |
597 | printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len); | |
598 | goto out_fail; | |
599 | out_oom: | |
600 | if (net_ratelimit()) | |
601 | printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n"); | |
602 | out_fail: | |
a11d206d YH |
603 | rcu_read_lock(); |
604 | IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
605 | rcu_read_unlock(); | |
1da177e4 LT |
606 | return -1; |
607 | } | |
608 | ||
e5bbef20 | 609 | static int ipv6_frag_rcv(struct sk_buff *skb) |
1da177e4 | 610 | { |
1da177e4 LT |
611 | struct frag_hdr *fhdr; |
612 | struct frag_queue *fq; | |
0660e03f | 613 | struct ipv6hdr *hdr = ipv6_hdr(skb); |
1da177e4 | 614 | |
a11d206d | 615 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS); |
1da177e4 LT |
616 | |
617 | /* Jumbo payload inhibits frag. header */ | |
618 | if (hdr->payload_len==0) { | |
a11d206d | 619 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
cfe1fc77 ACM |
620 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
621 | skb_network_header_len(skb)); | |
1da177e4 LT |
622 | return -1; |
623 | } | |
ea2ae17d ACM |
624 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + |
625 | sizeof(struct frag_hdr)))) { | |
a11d206d | 626 | IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
cfe1fc77 ACM |
627 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
628 | skb_network_header_len(skb)); | |
1da177e4 LT |
629 | return -1; |
630 | } | |
631 | ||
0660e03f | 632 | hdr = ipv6_hdr(skb); |
9c70220b | 633 | fhdr = (struct frag_hdr *)skb_transport_header(skb); |
1da177e4 LT |
634 | |
635 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
636 | /* It is not a fragmented frame */ | |
b0e380b1 | 637 | skb->transport_header += sizeof(struct frag_hdr); |
a11d206d | 638 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS); |
1da177e4 | 639 | |
d56f90a7 | 640 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); |
1da177e4 LT |
641 | return 1; |
642 | } | |
643 | ||
04128f23 | 644 | if (atomic_read(&ip6_frags.mem) > ip6_frags_ctl.high_thresh) |
a11d206d | 645 | ip6_evictor(ip6_dst_idev(skb->dst)); |
1da177e4 | 646 | |
a11d206d YH |
647 | if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr, |
648 | ip6_dst_idev(skb->dst))) != NULL) { | |
f61944ef | 649 | int ret; |
1da177e4 | 650 | |
5ab11c98 | 651 | spin_lock(&fq->q.lock); |
1da177e4 | 652 | |
f61944ef | 653 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); |
1da177e4 | 654 | |
5ab11c98 | 655 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 656 | fq_put(fq); |
1da177e4 LT |
657 | return ret; |
658 | } | |
659 | ||
a11d206d | 660 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
661 | kfree_skb(skb); |
662 | return -1; | |
663 | } | |
664 | ||
665 | static struct inet6_protocol frag_protocol = | |
666 | { | |
667 | .handler = ipv6_frag_rcv, | |
668 | .flags = INET6_PROTO_NOPOLICY, | |
669 | }; | |
670 | ||
671 | void __init ipv6_frag_init(void) | |
672 | { | |
673 | if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0) | |
674 | printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n"); | |
675 | ||
04128f23 | 676 | ip6_frags.ctl = &ip6_frags_ctl; |
321a3a99 | 677 | ip6_frags.hashfn = ip6_hashfn; |
1e4b8287 PE |
678 | ip6_frags.destructor = ip6_frag_free; |
679 | ip6_frags.skb_free = NULL; | |
680 | ip6_frags.qsize = sizeof(struct frag_queue); | |
2588fe1d | 681 | ip6_frags.equal = ip6_frag_equal; |
e521db9d | 682 | ip6_frags.frag_expire = ip6_frag_expire; |
7eb95156 | 683 | inet_frags_init(&ip6_frags); |
1da177e4 | 684 | } |