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Commit | Line | Data |
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9fb9cbb1 YK |
1 | /* |
2 | * IPv6 fragment reassembly for connection tracking | |
3 | * | |
4 | * Copyright (C)2004 USAGI/WIDE Project | |
5 | * | |
6 | * Author: | |
7 | * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
8 | * | |
9 | * Based on: net/ipv6/reassembly.c | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | */ | |
16 | ||
9fb9cbb1 YK |
17 | #include <linux/errno.h> |
18 | #include <linux/types.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/socket.h> | |
21 | #include <linux/sockios.h> | |
22 | #include <linux/jiffies.h> | |
23 | #include <linux/net.h> | |
24 | #include <linux/list.h> | |
25 | #include <linux/netdevice.h> | |
26 | #include <linux/in6.h> | |
27 | #include <linux/ipv6.h> | |
28 | #include <linux/icmpv6.h> | |
29 | #include <linux/random.h> | |
9fb9cbb1 YK |
30 | |
31 | #include <net/sock.h> | |
32 | #include <net/snmp.h> | |
5ab11c98 | 33 | #include <net/inet_frag.h> |
9fb9cbb1 YK |
34 | |
35 | #include <net/ipv6.h> | |
36 | #include <net/protocol.h> | |
37 | #include <net/transp_v6.h> | |
38 | #include <net/rawv6.h> | |
39 | #include <net/ndisc.h> | |
40 | #include <net/addrconf.h> | |
99fa5f53 | 41 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
9fb9cbb1 YK |
42 | #include <linux/sysctl.h> |
43 | #include <linux/netfilter.h> | |
44 | #include <linux/netfilter_ipv6.h> | |
45 | #include <linux/kernel.h> | |
46 | #include <linux/module.h> | |
47 | ||
9fb9cbb1 | 48 | |
9fb9cbb1 YK |
49 | struct nf_ct_frag6_skb_cb |
50 | { | |
51 | struct inet6_skb_parm h; | |
52 | int offset; | |
53 | struct sk_buff *orig; | |
54 | }; | |
55 | ||
56 | #define NFCT_FRAG6_CB(skb) ((struct nf_ct_frag6_skb_cb*)((skb)->cb)) | |
57 | ||
58 | struct nf_ct_frag6_queue | |
59 | { | |
5ab11c98 | 60 | struct inet_frag_queue q; |
9fb9cbb1 | 61 | |
bff9a89b | 62 | __be32 id; /* fragment id */ |
9fb9cbb1 YK |
63 | struct in6_addr saddr; |
64 | struct in6_addr daddr; | |
65 | ||
9fb9cbb1 | 66 | unsigned int csum; |
9fb9cbb1 | 67 | __u16 nhoffset; |
9fb9cbb1 YK |
68 | }; |
69 | ||
7eb95156 | 70 | static struct inet_frags nf_frags; |
ac18e750 | 71 | static struct netns_frags nf_init_frags; |
9fb9cbb1 | 72 | |
8d8354d2 PE |
73 | #ifdef CONFIG_SYSCTL |
74 | struct ctl_table nf_ct_ipv6_sysctl_table[] = { | |
75 | { | |
76 | .procname = "nf_conntrack_frag6_timeout", | |
b2fd5321 | 77 | .data = &nf_init_frags.timeout, |
8d8354d2 PE |
78 | .maxlen = sizeof(unsigned int), |
79 | .mode = 0644, | |
6d9f239a | 80 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
81 | }, |
82 | { | |
8d8354d2 | 83 | .procname = "nf_conntrack_frag6_low_thresh", |
e31e0bdc | 84 | .data = &nf_init_frags.low_thresh, |
8d8354d2 PE |
85 | .maxlen = sizeof(unsigned int), |
86 | .mode = 0644, | |
6d9f239a | 87 | .proc_handler = proc_dointvec, |
8d8354d2 PE |
88 | }, |
89 | { | |
8d8354d2 | 90 | .procname = "nf_conntrack_frag6_high_thresh", |
e31e0bdc | 91 | .data = &nf_init_frags.high_thresh, |
8d8354d2 PE |
92 | .maxlen = sizeof(unsigned int), |
93 | .mode = 0644, | |
6d9f239a | 94 | .proc_handler = proc_dointvec, |
8d8354d2 | 95 | }, |
f8572d8f | 96 | { } |
8d8354d2 PE |
97 | }; |
98 | #endif | |
99 | ||
321a3a99 | 100 | static unsigned int nf_hashfn(struct inet_frag_queue *q) |
9fb9cbb1 | 101 | { |
58c0fb0d | 102 | const struct nf_ct_frag6_queue *nq; |
9fb9cbb1 | 103 | |
321a3a99 | 104 | nq = container_of(q, struct nf_ct_frag6_queue, q); |
93c8b90f | 105 | return inet6_hash_frag(nq->id, &nq->saddr, &nq->daddr, nf_frags.rnd); |
9fb9cbb1 YK |
106 | } |
107 | ||
1e4b8287 PE |
108 | static void nf_skb_free(struct sk_buff *skb) |
109 | { | |
110 | if (NFCT_FRAG6_CB(skb)->orig) | |
111 | kfree_skb(NFCT_FRAG6_CB(skb)->orig); | |
112 | } | |
113 | ||
9fb9cbb1 | 114 | /* Memory Tracking Functions. */ |
1ba430bc | 115 | static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work) |
9fb9cbb1 | 116 | { |
1ba430bc YK |
117 | if (work) |
118 | *work -= skb->truesize; | |
6ddc0822 | 119 | atomic_sub(skb->truesize, &nf_init_frags.mem); |
1e4b8287 | 120 | nf_skb_free(skb); |
9fb9cbb1 YK |
121 | kfree_skb(skb); |
122 | } | |
123 | ||
9fb9cbb1 YK |
124 | /* Destruction primitives. */ |
125 | ||
4b6cb5d8 | 126 | static __inline__ void fq_put(struct nf_ct_frag6_queue *fq) |
9fb9cbb1 | 127 | { |
762cc408 | 128 | inet_frag_put(&fq->q, &nf_frags); |
9fb9cbb1 YK |
129 | } |
130 | ||
131 | /* Kill fq entry. It is not destroyed immediately, | |
132 | * because caller (and someone more) holds reference count. | |
133 | */ | |
134 | static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq) | |
135 | { | |
277e650d | 136 | inet_frag_kill(&fq->q, &nf_frags); |
9fb9cbb1 YK |
137 | } |
138 | ||
139 | static void nf_ct_frag6_evictor(void) | |
140 | { | |
e8e16b70 | 141 | local_bh_disable(); |
6ddc0822 | 142 | inet_frag_evictor(&nf_init_frags, &nf_frags); |
e8e16b70 | 143 | local_bh_enable(); |
9fb9cbb1 YK |
144 | } |
145 | ||
146 | static void nf_ct_frag6_expire(unsigned long data) | |
147 | { | |
e521db9d PE |
148 | struct nf_ct_frag6_queue *fq; |
149 | ||
150 | fq = container_of((struct inet_frag_queue *)data, | |
151 | struct nf_ct_frag6_queue, q); | |
9fb9cbb1 | 152 | |
5ab11c98 | 153 | spin_lock(&fq->q.lock); |
9fb9cbb1 | 154 | |
bc578a54 | 155 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
9fb9cbb1 YK |
156 | goto out; |
157 | ||
158 | fq_kill(fq); | |
159 | ||
160 | out: | |
5ab11c98 | 161 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 162 | fq_put(fq); |
9fb9cbb1 YK |
163 | } |
164 | ||
165 | /* Creation primitives. */ | |
166 | ||
abd6523d | 167 | static __inline__ struct nf_ct_frag6_queue * |
0b5ccb2e | 168 | fq_find(__be32 id, u32 user, struct in6_addr *src, struct in6_addr *dst) |
9fb9cbb1 | 169 | { |
2588fe1d | 170 | struct inet_frag_queue *q; |
c6fda282 | 171 | struct ip6_create_arg arg; |
abd6523d | 172 | unsigned int hash; |
9fb9cbb1 | 173 | |
c6fda282 | 174 | arg.id = id; |
0b5ccb2e | 175 | arg.user = user; |
c6fda282 PE |
176 | arg.src = src; |
177 | arg.dst = dst; | |
9a375803 PE |
178 | |
179 | read_lock_bh(&nf_frags.lock); | |
93c8b90f | 180 | hash = inet6_hash_frag(id, src, dst, nf_frags.rnd); |
9fb9cbb1 | 181 | |
ac18e750 | 182 | q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash); |
b9c69896 | 183 | local_bh_enable(); |
c6fda282 | 184 | if (q == NULL) |
9fb9cbb1 | 185 | goto oom; |
9fb9cbb1 | 186 | |
c6fda282 | 187 | return container_of(q, struct nf_ct_frag6_queue, q); |
9fb9cbb1 YK |
188 | |
189 | oom: | |
c6fda282 | 190 | pr_debug("Can't alloc new queue\n"); |
9fb9cbb1 YK |
191 | return NULL; |
192 | } | |
193 | ||
9fb9cbb1 | 194 | |
1ab1457c | 195 | static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb, |
58c0fb0d | 196 | const struct frag_hdr *fhdr, int nhoff) |
9fb9cbb1 YK |
197 | { |
198 | struct sk_buff *prev, *next; | |
199 | int offset, end; | |
200 | ||
bc578a54 | 201 | if (fq->q.last_in & INET_FRAG_COMPLETE) { |
0d53778e | 202 | pr_debug("Allready completed\n"); |
9fb9cbb1 YK |
203 | goto err; |
204 | } | |
205 | ||
206 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
207 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
208 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
9fb9cbb1 YK |
209 | |
210 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
0d53778e | 211 | pr_debug("offset is too large.\n"); |
1ab1457c | 212 | return -1; |
9fb9cbb1 YK |
213 | } |
214 | ||
d56f90a7 ACM |
215 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
216 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 217 | skb->csum = csum_sub(skb->csum, |
d56f90a7 | 218 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
9fb9cbb1 | 219 | 0)); |
d56f90a7 | 220 | } |
9fb9cbb1 YK |
221 | |
222 | /* Is this the final fragment? */ | |
223 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
224 | /* If we already have some bits beyond end | |
225 | * or have different end, the segment is corrupted. | |
226 | */ | |
5ab11c98 | 227 | if (end < fq->q.len || |
bc578a54 | 228 | ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) { |
0d53778e | 229 | pr_debug("already received last fragment\n"); |
9fb9cbb1 YK |
230 | goto err; |
231 | } | |
bc578a54 | 232 | fq->q.last_in |= INET_FRAG_LAST_IN; |
5ab11c98 | 233 | fq->q.len = end; |
9fb9cbb1 YK |
234 | } else { |
235 | /* Check if the fragment is rounded to 8 bytes. | |
236 | * Required by the RFC. | |
237 | */ | |
238 | if (end & 0x7) { | |
239 | /* RFC2460 says always send parameter problem in | |
240 | * this case. -DaveM | |
241 | */ | |
0d53778e | 242 | pr_debug("end of fragment not rounded to 8 bytes.\n"); |
9fb9cbb1 YK |
243 | return -1; |
244 | } | |
5ab11c98 | 245 | if (end > fq->q.len) { |
9fb9cbb1 | 246 | /* Some bits beyond end -> corruption. */ |
bc578a54 | 247 | if (fq->q.last_in & INET_FRAG_LAST_IN) { |
0d53778e | 248 | pr_debug("last packet already reached.\n"); |
9fb9cbb1 YK |
249 | goto err; |
250 | } | |
5ab11c98 | 251 | fq->q.len = end; |
9fb9cbb1 YK |
252 | } |
253 | } | |
254 | ||
255 | if (end == offset) | |
256 | goto err; | |
257 | ||
258 | /* Point into the IP datagram 'data' part. */ | |
259 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) { | |
0d53778e | 260 | pr_debug("queue: message is too short.\n"); |
9fb9cbb1 YK |
261 | goto err; |
262 | } | |
b38dfee3 | 263 | if (pskb_trim_rcsum(skb, end - offset)) { |
0d53778e | 264 | pr_debug("Can't trim\n"); |
b38dfee3 | 265 | goto err; |
9fb9cbb1 YK |
266 | } |
267 | ||
268 | /* Find out which fragments are in front and at the back of us | |
269 | * in the chain of fragments so far. We must know where to put | |
270 | * this fragment, right? | |
271 | */ | |
272 | prev = NULL; | |
5ab11c98 | 273 | for (next = fq->q.fragments; next != NULL; next = next->next) { |
9fb9cbb1 YK |
274 | if (NFCT_FRAG6_CB(next)->offset >= offset) |
275 | break; /* bingo! */ | |
276 | prev = next; | |
277 | } | |
278 | ||
279 | /* We found where to put this one. Check for overlap with | |
280 | * preceding fragment, and, if needed, align things so that | |
281 | * any overlaps are eliminated. | |
282 | */ | |
283 | if (prev) { | |
284 | int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset; | |
285 | ||
286 | if (i > 0) { | |
287 | offset += i; | |
288 | if (end <= offset) { | |
0d53778e | 289 | pr_debug("overlap\n"); |
9fb9cbb1 YK |
290 | goto err; |
291 | } | |
292 | if (!pskb_pull(skb, i)) { | |
0d53778e | 293 | pr_debug("Can't pull\n"); |
9fb9cbb1 YK |
294 | goto err; |
295 | } | |
296 | if (skb->ip_summed != CHECKSUM_UNNECESSARY) | |
297 | skb->ip_summed = CHECKSUM_NONE; | |
298 | } | |
299 | } | |
300 | ||
301 | /* Look for overlap with succeeding segments. | |
302 | * If we can merge fragments, do it. | |
303 | */ | |
304 | while (next && NFCT_FRAG6_CB(next)->offset < end) { | |
305 | /* overlap is 'i' bytes */ | |
306 | int i = end - NFCT_FRAG6_CB(next)->offset; | |
307 | ||
308 | if (i < next->len) { | |
309 | /* Eat head of the next overlapped fragment | |
310 | * and leave the loop. The next ones cannot overlap. | |
311 | */ | |
0d53778e | 312 | pr_debug("Eat head of the overlapped parts.: %d", i); |
9fb9cbb1 YK |
313 | if (!pskb_pull(next, i)) |
314 | goto err; | |
315 | ||
316 | /* next fragment */ | |
317 | NFCT_FRAG6_CB(next)->offset += i; | |
5ab11c98 | 318 | fq->q.meat -= i; |
9fb9cbb1 YK |
319 | if (next->ip_summed != CHECKSUM_UNNECESSARY) |
320 | next->ip_summed = CHECKSUM_NONE; | |
321 | break; | |
322 | } else { | |
323 | struct sk_buff *free_it = next; | |
324 | ||
325 | /* Old fragmnet is completely overridden with | |
326 | * new one drop it. | |
327 | */ | |
328 | next = next->next; | |
329 | ||
330 | if (prev) | |
331 | prev->next = next; | |
332 | else | |
5ab11c98 | 333 | fq->q.fragments = next; |
9fb9cbb1 | 334 | |
5ab11c98 | 335 | fq->q.meat -= free_it->len; |
1ba430bc | 336 | frag_kfree_skb(free_it, NULL); |
9fb9cbb1 YK |
337 | } |
338 | } | |
339 | ||
340 | NFCT_FRAG6_CB(skb)->offset = offset; | |
341 | ||
342 | /* Insert this fragment in the chain of fragments. */ | |
343 | skb->next = next; | |
344 | if (prev) | |
345 | prev->next = skb; | |
346 | else | |
5ab11c98 | 347 | fq->q.fragments = skb; |
9fb9cbb1 YK |
348 | |
349 | skb->dev = NULL; | |
5ab11c98 PE |
350 | fq->q.stamp = skb->tstamp; |
351 | fq->q.meat += skb->len; | |
6ddc0822 | 352 | atomic_add(skb->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
353 | |
354 | /* The first fragment. | |
355 | * nhoffset is obtained from the first fragment, of course. | |
356 | */ | |
357 | if (offset == 0) { | |
358 | fq->nhoffset = nhoff; | |
bc578a54 | 359 | fq->q.last_in |= INET_FRAG_FIRST_IN; |
9fb9cbb1 | 360 | } |
7eb95156 | 361 | write_lock(&nf_frags.lock); |
3140c25c | 362 | list_move_tail(&fq->q.lru_list, &nf_init_frags.lru_list); |
7eb95156 | 363 | write_unlock(&nf_frags.lock); |
9fb9cbb1 YK |
364 | return 0; |
365 | ||
366 | err: | |
367 | return -1; | |
368 | } | |
369 | ||
370 | /* | |
371 | * Check if this packet is complete. | |
372 | * Returns NULL on failure by any reason, and pointer | |
373 | * to current nexthdr field in reassembled frame. | |
374 | * | |
375 | * It is called with locked fq, and caller must check that | |
376 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
377 | * the last and the first frames arrived and all the bits are here. | |
378 | */ | |
379 | static struct sk_buff * | |
380 | nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev) | |
381 | { | |
5ab11c98 | 382 | struct sk_buff *fp, *op, *head = fq->q.fragments; |
9fb9cbb1 YK |
383 | int payload_len; |
384 | ||
385 | fq_kill(fq); | |
386 | ||
547b792c IJ |
387 | WARN_ON(head == NULL); |
388 | WARN_ON(NFCT_FRAG6_CB(head)->offset != 0); | |
9fb9cbb1 YK |
389 | |
390 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 391 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 392 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 393 | sizeof(struct frag_hdr)); |
9fb9cbb1 | 394 | if (payload_len > IPV6_MAXPLEN) { |
0d53778e | 395 | pr_debug("payload len is too large.\n"); |
9fb9cbb1 YK |
396 | goto out_oversize; |
397 | } | |
398 | ||
399 | /* Head of list must not be cloned. */ | |
400 | if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) { | |
0d53778e | 401 | pr_debug("skb is cloned but can't expand head"); |
9fb9cbb1 YK |
402 | goto out_oom; |
403 | } | |
404 | ||
405 | /* If the first fragment is fragmented itself, we split | |
406 | * it to two chunks: the first with data and paged part | |
407 | * and the second, holding only fragments. */ | |
343a9972 | 408 | if (skb_has_frags(head)) { |
9fb9cbb1 YK |
409 | struct sk_buff *clone; |
410 | int i, plen = 0; | |
411 | ||
412 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) { | |
0d53778e | 413 | pr_debug("Can't alloc skb\n"); |
9fb9cbb1 YK |
414 | goto out_oom; |
415 | } | |
416 | clone->next = head->next; | |
417 | head->next = clone; | |
418 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
343a9972 | 419 | skb_frag_list_init(head); |
9fb9cbb1 YK |
420 | for (i=0; i<skb_shinfo(head)->nr_frags; i++) |
421 | plen += skb_shinfo(head)->frags[i].size; | |
422 | clone->len = clone->data_len = head->data_len - plen; | |
423 | head->data_len -= clone->len; | |
424 | head->len -= clone->len; | |
425 | clone->csum = 0; | |
426 | clone->ip_summed = head->ip_summed; | |
427 | ||
428 | NFCT_FRAG6_CB(clone)->orig = NULL; | |
6ddc0822 | 429 | atomic_add(clone->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
430 | } |
431 | ||
432 | /* We have to remove fragment header from datagram and to relocate | |
433 | * header in order to calculate ICV correctly. */ | |
bff9b61c | 434 | skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0]; |
1ab1457c | 435 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
9fb9cbb1 | 436 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
437 | head->mac_header += sizeof(struct frag_hdr); |
438 | head->network_header += sizeof(struct frag_hdr); | |
9fb9cbb1 YK |
439 | |
440 | skb_shinfo(head)->frag_list = head->next; | |
badff6d0 | 441 | skb_reset_transport_header(head); |
d56f90a7 | 442 | skb_push(head, head->data - skb_network_header(head)); |
6ddc0822 | 443 | atomic_sub(head->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
444 | |
445 | for (fp=head->next; fp; fp = fp->next) { | |
446 | head->data_len += fp->len; | |
447 | head->len += fp->len; | |
448 | if (head->ip_summed != fp->ip_summed) | |
449 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 450 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
9fb9cbb1 YK |
451 | head->csum = csum_add(head->csum, fp->csum); |
452 | head->truesize += fp->truesize; | |
6ddc0822 | 453 | atomic_sub(fp->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
454 | } |
455 | ||
456 | head->next = NULL; | |
457 | head->dev = dev; | |
5ab11c98 | 458 | head->tstamp = fq->q.stamp; |
0660e03f | 459 | ipv6_hdr(head)->payload_len = htons(payload_len); |
9fb9cbb1 YK |
460 | |
461 | /* Yes, and fold redundant checksum back. 8) */ | |
84fa7933 | 462 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 463 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 464 | skb_network_header_len(head), |
d56f90a7 | 465 | head->csum); |
9fb9cbb1 | 466 | |
5ab11c98 | 467 | fq->q.fragments = NULL; |
9fb9cbb1 YK |
468 | |
469 | /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */ | |
470 | fp = skb_shinfo(head)->frag_list; | |
471 | if (NFCT_FRAG6_CB(fp)->orig == NULL) | |
472 | /* at above code, head skb is divided into two skbs. */ | |
473 | fp = fp->next; | |
474 | ||
475 | op = NFCT_FRAG6_CB(head)->orig; | |
476 | for (; fp; fp = fp->next) { | |
477 | struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig; | |
478 | ||
479 | op->next = orig; | |
480 | op = orig; | |
481 | NFCT_FRAG6_CB(fp)->orig = NULL; | |
482 | } | |
483 | ||
484 | return head; | |
485 | ||
486 | out_oversize: | |
487 | if (net_ratelimit()) | |
488 | printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len); | |
489 | goto out_fail; | |
490 | out_oom: | |
491 | if (net_ratelimit()) | |
492 | printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n"); | |
493 | out_fail: | |
494 | return NULL; | |
495 | } | |
496 | ||
497 | /* | |
498 | * find the header just before Fragment Header. | |
499 | * | |
500 | * if success return 0 and set ... | |
501 | * (*prevhdrp): the value of "Next Header Field" in the header | |
502 | * just before Fragment Header. | |
503 | * (*prevhoff): the offset of "Next Header Field" in the header | |
504 | * just before Fragment Header. | |
505 | * (*fhoff) : the offset of Fragment Header. | |
506 | * | |
507 | * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c | |
508 | * | |
509 | */ | |
510 | static int | |
511 | find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff) | |
512 | { | |
0660e03f | 513 | u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
6b88dd96 ACM |
514 | const int netoff = skb_network_offset(skb); |
515 | u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr); | |
516 | int start = netoff + sizeof(struct ipv6hdr); | |
9fb9cbb1 YK |
517 | int len = skb->len - start; |
518 | u8 prevhdr = NEXTHDR_IPV6; | |
519 | ||
1ab1457c YH |
520 | while (nexthdr != NEXTHDR_FRAGMENT) { |
521 | struct ipv6_opt_hdr hdr; | |
522 | int hdrlen; | |
9fb9cbb1 YK |
523 | |
524 | if (!ipv6_ext_hdr(nexthdr)) { | |
525 | return -1; | |
526 | } | |
1ab1457c | 527 | if (nexthdr == NEXTHDR_NONE) { |
0d53778e | 528 | pr_debug("next header is none\n"); |
9fb9cbb1 YK |
529 | return -1; |
530 | } | |
d1238d53 CP |
531 | if (len < (int)sizeof(struct ipv6_opt_hdr)) { |
532 | pr_debug("too short\n"); | |
533 | return -1; | |
534 | } | |
1ab1457c YH |
535 | if (skb_copy_bits(skb, start, &hdr, sizeof(hdr))) |
536 | BUG(); | |
537 | if (nexthdr == NEXTHDR_AUTH) | |
538 | hdrlen = (hdr.hdrlen+2)<<2; | |
539 | else | |
540 | hdrlen = ipv6_optlen(&hdr); | |
9fb9cbb1 YK |
541 | |
542 | prevhdr = nexthdr; | |
543 | prev_nhoff = start; | |
544 | ||
1ab1457c YH |
545 | nexthdr = hdr.nexthdr; |
546 | len -= hdrlen; | |
547 | start += hdrlen; | |
548 | } | |
9fb9cbb1 YK |
549 | |
550 | if (len < 0) | |
551 | return -1; | |
552 | ||
553 | *prevhdrp = prevhdr; | |
554 | *prevhoff = prev_nhoff; | |
555 | *fhoff = start; | |
556 | ||
557 | return 0; | |
558 | } | |
559 | ||
0b5ccb2e | 560 | struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user) |
9fb9cbb1 | 561 | { |
1ab1457c | 562 | struct sk_buff *clone; |
9fb9cbb1 YK |
563 | struct net_device *dev = skb->dev; |
564 | struct frag_hdr *fhdr; | |
565 | struct nf_ct_frag6_queue *fq; | |
566 | struct ipv6hdr *hdr; | |
567 | int fhoff, nhoff; | |
568 | u8 prevhdr; | |
569 | struct sk_buff *ret_skb = NULL; | |
570 | ||
571 | /* Jumbo payload inhibits frag. header */ | |
0660e03f | 572 | if (ipv6_hdr(skb)->payload_len == 0) { |
0d53778e | 573 | pr_debug("payload len = 0\n"); |
9fb9cbb1 YK |
574 | return skb; |
575 | } | |
576 | ||
577 | if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0) | |
578 | return skb; | |
579 | ||
580 | clone = skb_clone(skb, GFP_ATOMIC); | |
581 | if (clone == NULL) { | |
0d53778e | 582 | pr_debug("Can't clone skb\n"); |
9fb9cbb1 YK |
583 | return skb; |
584 | } | |
585 | ||
586 | NFCT_FRAG6_CB(clone)->orig = skb; | |
587 | ||
588 | if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) { | |
0d53778e | 589 | pr_debug("message is too short.\n"); |
9fb9cbb1 YK |
590 | goto ret_orig; |
591 | } | |
592 | ||
967b05f6 | 593 | skb_set_transport_header(clone, fhoff); |
0660e03f | 594 | hdr = ipv6_hdr(clone); |
bff9b61c | 595 | fhdr = (struct frag_hdr *)skb_transport_header(clone); |
9fb9cbb1 YK |
596 | |
597 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
0d53778e | 598 | pr_debug("Invalid fragment offset\n"); |
9fb9cbb1 YK |
599 | /* It is not a fragmented frame */ |
600 | goto ret_orig; | |
601 | } | |
602 | ||
e31e0bdc | 603 | if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh) |
9fb9cbb1 YK |
604 | nf_ct_frag6_evictor(); |
605 | ||
0b5ccb2e | 606 | fq = fq_find(fhdr->identification, user, &hdr->saddr, &hdr->daddr); |
9fb9cbb1 | 607 | if (fq == NULL) { |
0d53778e | 608 | pr_debug("Can't find and can't create new queue\n"); |
9fb9cbb1 YK |
609 | goto ret_orig; |
610 | } | |
611 | ||
b9c69896 | 612 | spin_lock_bh(&fq->q.lock); |
9fb9cbb1 YK |
613 | |
614 | if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) { | |
b9c69896 | 615 | spin_unlock_bh(&fq->q.lock); |
0d53778e | 616 | pr_debug("Can't insert skb to queue\n"); |
4b6cb5d8 | 617 | fq_put(fq); |
9fb9cbb1 YK |
618 | goto ret_orig; |
619 | } | |
620 | ||
bc578a54 JP |
621 | if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
622 | fq->q.meat == fq->q.len) { | |
9fb9cbb1 YK |
623 | ret_skb = nf_ct_frag6_reasm(fq, dev); |
624 | if (ret_skb == NULL) | |
0d53778e | 625 | pr_debug("Can't reassemble fragmented packets\n"); |
9fb9cbb1 | 626 | } |
b9c69896 | 627 | spin_unlock_bh(&fq->q.lock); |
9fb9cbb1 | 628 | |
4b6cb5d8 | 629 | fq_put(fq); |
9fb9cbb1 YK |
630 | return ret_skb; |
631 | ||
632 | ret_orig: | |
633 | kfree_skb(clone); | |
634 | return skb; | |
635 | } | |
636 | ||
637 | void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb, | |
638 | struct net_device *in, struct net_device *out, | |
639 | int (*okfn)(struct sk_buff *)) | |
640 | { | |
641 | struct sk_buff *s, *s2; | |
642 | ||
643 | for (s = NFCT_FRAG6_CB(skb)->orig; s;) { | |
644 | nf_conntrack_put_reasm(s->nfct_reasm); | |
645 | nf_conntrack_get_reasm(skb); | |
646 | s->nfct_reasm = skb; | |
647 | ||
648 | s2 = s->next; | |
f9f02cca PM |
649 | s->next = NULL; |
650 | ||
9fb9cbb1 YK |
651 | NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn, |
652 | NF_IP6_PRI_CONNTRACK_DEFRAG + 1); | |
653 | s = s2; | |
654 | } | |
655 | nf_conntrack_put_reasm(skb); | |
656 | } | |
657 | ||
9fb9cbb1 YK |
658 | int nf_ct_frag6_init(void) |
659 | { | |
321a3a99 | 660 | nf_frags.hashfn = nf_hashfn; |
c6fda282 | 661 | nf_frags.constructor = ip6_frag_init; |
c9547709 | 662 | nf_frags.destructor = NULL; |
1e4b8287 PE |
663 | nf_frags.skb_free = nf_skb_free; |
664 | nf_frags.qsize = sizeof(struct nf_ct_frag6_queue); | |
abd6523d | 665 | nf_frags.match = ip6_frag_match; |
e521db9d | 666 | nf_frags.frag_expire = nf_ct_frag6_expire; |
3b4bc4a2 | 667 | nf_frags.secret_interval = 10 * 60 * HZ; |
b2fd5321 | 668 | nf_init_frags.timeout = IPV6_FRAG_TIMEOUT; |
7c070aa9 SW |
669 | nf_init_frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
670 | nf_init_frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
e5a2bb84 | 671 | inet_frags_init_net(&nf_init_frags); |
7eb95156 | 672 | inet_frags_init(&nf_frags); |
9fb9cbb1 YK |
673 | |
674 | return 0; | |
675 | } | |
676 | ||
677 | void nf_ct_frag6_cleanup(void) | |
678 | { | |
7eb95156 PE |
679 | inet_frags_fini(&nf_frags); |
680 | ||
e31e0bdc | 681 | nf_init_frags.low_thresh = 0; |
9fb9cbb1 YK |
682 | nf_ct_frag6_evictor(); |
683 | } |