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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> | |
5a0e3ad6 | 30 | #include <linux/slab.h> |
9fb9cbb1 YK |
31 | |
32 | #include <net/sock.h> | |
33 | #include <net/snmp.h> | |
5ab11c98 | 34 | #include <net/inet_frag.h> |
9fb9cbb1 YK |
35 | |
36 | #include <net/ipv6.h> | |
37 | #include <net/protocol.h> | |
38 | #include <net/transp_v6.h> | |
39 | #include <net/rawv6.h> | |
40 | #include <net/ndisc.h> | |
41 | #include <net/addrconf.h> | |
99fa5f53 | 42 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
9fb9cbb1 YK |
43 | #include <linux/sysctl.h> |
44 | #include <linux/netfilter.h> | |
45 | #include <linux/netfilter_ipv6.h> | |
46 | #include <linux/kernel.h> | |
47 | #include <linux/module.h> | |
48 | ||
9fb9cbb1 | 49 | |
9fb9cbb1 YK |
50 | struct nf_ct_frag6_skb_cb |
51 | { | |
52 | struct inet6_skb_parm h; | |
53 | int offset; | |
54 | struct sk_buff *orig; | |
55 | }; | |
56 | ||
57 | #define NFCT_FRAG6_CB(skb) ((struct nf_ct_frag6_skb_cb*)((skb)->cb)) | |
58 | ||
59 | struct nf_ct_frag6_queue | |
60 | { | |
5ab11c98 | 61 | struct inet_frag_queue q; |
9fb9cbb1 | 62 | |
bff9a89b | 63 | __be32 id; /* fragment id */ |
c92b544b | 64 | u32 user; |
9fb9cbb1 YK |
65 | struct in6_addr saddr; |
66 | struct in6_addr daddr; | |
67 | ||
9fb9cbb1 | 68 | unsigned int csum; |
9fb9cbb1 | 69 | __u16 nhoffset; |
9fb9cbb1 YK |
70 | }; |
71 | ||
7eb95156 | 72 | static struct inet_frags nf_frags; |
ac18e750 | 73 | static struct netns_frags nf_init_frags; |
9fb9cbb1 | 74 | |
8d8354d2 | 75 | #ifdef CONFIG_SYSCTL |
e97c3e27 | 76 | struct ctl_table nf_ct_frag6_sysctl_table[] = { |
8d8354d2 PE |
77 | { |
78 | .procname = "nf_conntrack_frag6_timeout", | |
b2fd5321 | 79 | .data = &nf_init_frags.timeout, |
8d8354d2 PE |
80 | .maxlen = sizeof(unsigned int), |
81 | .mode = 0644, | |
6d9f239a | 82 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
83 | }, |
84 | { | |
8d8354d2 | 85 | .procname = "nf_conntrack_frag6_low_thresh", |
e31e0bdc | 86 | .data = &nf_init_frags.low_thresh, |
8d8354d2 PE |
87 | .maxlen = sizeof(unsigned int), |
88 | .mode = 0644, | |
6d9f239a | 89 | .proc_handler = proc_dointvec, |
8d8354d2 PE |
90 | }, |
91 | { | |
8d8354d2 | 92 | .procname = "nf_conntrack_frag6_high_thresh", |
e31e0bdc | 93 | .data = &nf_init_frags.high_thresh, |
8d8354d2 PE |
94 | .maxlen = sizeof(unsigned int), |
95 | .mode = 0644, | |
6d9f239a | 96 | .proc_handler = proc_dointvec, |
8d8354d2 | 97 | }, |
f8572d8f | 98 | { } |
8d8354d2 | 99 | }; |
e97c3e27 BS |
100 | |
101 | static struct ctl_table_header *nf_ct_frag6_sysctl_header; | |
8d8354d2 PE |
102 | #endif |
103 | ||
321a3a99 | 104 | static unsigned int nf_hashfn(struct inet_frag_queue *q) |
9fb9cbb1 | 105 | { |
58c0fb0d | 106 | const struct nf_ct_frag6_queue *nq; |
9fb9cbb1 | 107 | |
321a3a99 | 108 | nq = container_of(q, struct nf_ct_frag6_queue, q); |
93c8b90f | 109 | return inet6_hash_frag(nq->id, &nq->saddr, &nq->daddr, nf_frags.rnd); |
9fb9cbb1 YK |
110 | } |
111 | ||
1e4b8287 PE |
112 | static void nf_skb_free(struct sk_buff *skb) |
113 | { | |
114 | if (NFCT_FRAG6_CB(skb)->orig) | |
115 | kfree_skb(NFCT_FRAG6_CB(skb)->orig); | |
116 | } | |
117 | ||
9fb9cbb1 YK |
118 | /* Destruction primitives. */ |
119 | ||
4b6cb5d8 | 120 | static __inline__ void fq_put(struct nf_ct_frag6_queue *fq) |
9fb9cbb1 | 121 | { |
762cc408 | 122 | inet_frag_put(&fq->q, &nf_frags); |
9fb9cbb1 YK |
123 | } |
124 | ||
125 | /* Kill fq entry. It is not destroyed immediately, | |
126 | * because caller (and someone more) holds reference count. | |
127 | */ | |
128 | static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq) | |
129 | { | |
277e650d | 130 | inet_frag_kill(&fq->q, &nf_frags); |
9fb9cbb1 YK |
131 | } |
132 | ||
133 | static void nf_ct_frag6_evictor(void) | |
134 | { | |
e8e16b70 | 135 | local_bh_disable(); |
6ddc0822 | 136 | inet_frag_evictor(&nf_init_frags, &nf_frags); |
e8e16b70 | 137 | local_bh_enable(); |
9fb9cbb1 YK |
138 | } |
139 | ||
140 | static void nf_ct_frag6_expire(unsigned long data) | |
141 | { | |
e521db9d PE |
142 | struct nf_ct_frag6_queue *fq; |
143 | ||
144 | fq = container_of((struct inet_frag_queue *)data, | |
145 | struct nf_ct_frag6_queue, q); | |
9fb9cbb1 | 146 | |
5ab11c98 | 147 | spin_lock(&fq->q.lock); |
9fb9cbb1 | 148 | |
bc578a54 | 149 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
9fb9cbb1 YK |
150 | goto out; |
151 | ||
152 | fq_kill(fq); | |
153 | ||
154 | out: | |
5ab11c98 | 155 | spin_unlock(&fq->q.lock); |
4b6cb5d8 | 156 | fq_put(fq); |
9fb9cbb1 YK |
157 | } |
158 | ||
159 | /* Creation primitives. */ | |
160 | ||
abd6523d | 161 | static __inline__ struct nf_ct_frag6_queue * |
0b5ccb2e | 162 | fq_find(__be32 id, u32 user, struct in6_addr *src, struct in6_addr *dst) |
9fb9cbb1 | 163 | { |
2588fe1d | 164 | struct inet_frag_queue *q; |
c6fda282 | 165 | struct ip6_create_arg arg; |
abd6523d | 166 | unsigned int hash; |
9fb9cbb1 | 167 | |
c6fda282 | 168 | arg.id = id; |
0b5ccb2e | 169 | arg.user = user; |
c6fda282 PE |
170 | arg.src = src; |
171 | arg.dst = dst; | |
9a375803 PE |
172 | |
173 | read_lock_bh(&nf_frags.lock); | |
93c8b90f | 174 | hash = inet6_hash_frag(id, src, dst, nf_frags.rnd); |
9fb9cbb1 | 175 | |
ac18e750 | 176 | q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash); |
b9c69896 | 177 | local_bh_enable(); |
c6fda282 | 178 | if (q == NULL) |
9fb9cbb1 | 179 | goto oom; |
9fb9cbb1 | 180 | |
c6fda282 | 181 | return container_of(q, struct nf_ct_frag6_queue, q); |
9fb9cbb1 YK |
182 | |
183 | oom: | |
c6fda282 | 184 | pr_debug("Can't alloc new queue\n"); |
9fb9cbb1 YK |
185 | return NULL; |
186 | } | |
187 | ||
9fb9cbb1 | 188 | |
1ab1457c | 189 | static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb, |
58c0fb0d | 190 | const struct frag_hdr *fhdr, int nhoff) |
9fb9cbb1 YK |
191 | { |
192 | struct sk_buff *prev, *next; | |
193 | int offset, end; | |
194 | ||
bc578a54 | 195 | if (fq->q.last_in & INET_FRAG_COMPLETE) { |
698f9315 | 196 | pr_debug("Already completed\n"); |
9fb9cbb1 YK |
197 | goto err; |
198 | } | |
199 | ||
200 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
201 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
202 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
9fb9cbb1 YK |
203 | |
204 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
0d53778e | 205 | pr_debug("offset is too large.\n"); |
1ab1457c | 206 | return -1; |
9fb9cbb1 YK |
207 | } |
208 | ||
d56f90a7 ACM |
209 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
210 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 211 | skb->csum = csum_sub(skb->csum, |
d56f90a7 | 212 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
9fb9cbb1 | 213 | 0)); |
d56f90a7 | 214 | } |
9fb9cbb1 YK |
215 | |
216 | /* Is this the final fragment? */ | |
217 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
218 | /* If we already have some bits beyond end | |
219 | * or have different end, the segment is corrupted. | |
220 | */ | |
5ab11c98 | 221 | if (end < fq->q.len || |
bc578a54 | 222 | ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) { |
0d53778e | 223 | pr_debug("already received last fragment\n"); |
9fb9cbb1 YK |
224 | goto err; |
225 | } | |
bc578a54 | 226 | fq->q.last_in |= INET_FRAG_LAST_IN; |
5ab11c98 | 227 | fq->q.len = end; |
9fb9cbb1 YK |
228 | } else { |
229 | /* Check if the fragment is rounded to 8 bytes. | |
230 | * Required by the RFC. | |
231 | */ | |
232 | if (end & 0x7) { | |
233 | /* RFC2460 says always send parameter problem in | |
234 | * this case. -DaveM | |
235 | */ | |
0d53778e | 236 | pr_debug("end of fragment not rounded to 8 bytes.\n"); |
9fb9cbb1 YK |
237 | return -1; |
238 | } | |
5ab11c98 | 239 | if (end > fq->q.len) { |
9fb9cbb1 | 240 | /* Some bits beyond end -> corruption. */ |
bc578a54 | 241 | if (fq->q.last_in & INET_FRAG_LAST_IN) { |
0d53778e | 242 | pr_debug("last packet already reached.\n"); |
9fb9cbb1 YK |
243 | goto err; |
244 | } | |
5ab11c98 | 245 | fq->q.len = end; |
9fb9cbb1 YK |
246 | } |
247 | } | |
248 | ||
249 | if (end == offset) | |
250 | goto err; | |
251 | ||
252 | /* Point into the IP datagram 'data' part. */ | |
253 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) { | |
0d53778e | 254 | pr_debug("queue: message is too short.\n"); |
9fb9cbb1 YK |
255 | goto err; |
256 | } | |
b38dfee3 | 257 | if (pskb_trim_rcsum(skb, end - offset)) { |
0d53778e | 258 | pr_debug("Can't trim\n"); |
b38dfee3 | 259 | goto err; |
9fb9cbb1 YK |
260 | } |
261 | ||
262 | /* Find out which fragments are in front and at the back of us | |
263 | * in the chain of fragments so far. We must know where to put | |
264 | * this fragment, right? | |
265 | */ | |
ea8fbe8f CG |
266 | prev = fq->q.fragments_tail; |
267 | if (!prev || NFCT_FRAG6_CB(prev)->offset < offset) { | |
268 | next = NULL; | |
269 | goto found; | |
270 | } | |
9fb9cbb1 | 271 | prev = NULL; |
5ab11c98 | 272 | for (next = fq->q.fragments; next != NULL; next = next->next) { |
9fb9cbb1 YK |
273 | if (NFCT_FRAG6_CB(next)->offset >= offset) |
274 | break; /* bingo! */ | |
275 | prev = next; | |
276 | } | |
277 | ||
ea8fbe8f | 278 | found: |
1ee89bd0 ND |
279 | /* RFC5722, Section 4: |
280 | * When reassembling an IPv6 datagram, if | |
281 | * one or more its constituent fragments is determined to be an | |
282 | * overlapping fragment, the entire datagram (and any constituent | |
283 | * fragments, including those not yet received) MUST be silently | |
284 | * discarded. | |
9fb9cbb1 | 285 | */ |
9fb9cbb1 | 286 | |
1ee89bd0 ND |
287 | /* Check for overlap with preceding fragment. */ |
288 | if (prev && | |
22e091e5 | 289 | (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset) |
1ee89bd0 | 290 | goto discard_fq; |
9fb9cbb1 | 291 | |
1ee89bd0 ND |
292 | /* Look for overlap with succeeding segment. */ |
293 | if (next && NFCT_FRAG6_CB(next)->offset < end) | |
294 | goto discard_fq; | |
9fb9cbb1 YK |
295 | |
296 | NFCT_FRAG6_CB(skb)->offset = offset; | |
297 | ||
298 | /* Insert this fragment in the chain of fragments. */ | |
299 | skb->next = next; | |
ea8fbe8f CG |
300 | if (!next) |
301 | fq->q.fragments_tail = skb; | |
9fb9cbb1 YK |
302 | if (prev) |
303 | prev->next = skb; | |
304 | else | |
5ab11c98 | 305 | fq->q.fragments = skb; |
9fb9cbb1 YK |
306 | |
307 | skb->dev = NULL; | |
5ab11c98 PE |
308 | fq->q.stamp = skb->tstamp; |
309 | fq->q.meat += skb->len; | |
6ddc0822 | 310 | atomic_add(skb->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
311 | |
312 | /* The first fragment. | |
313 | * nhoffset is obtained from the first fragment, of course. | |
314 | */ | |
315 | if (offset == 0) { | |
316 | fq->nhoffset = nhoff; | |
bc578a54 | 317 | fq->q.last_in |= INET_FRAG_FIRST_IN; |
9fb9cbb1 | 318 | } |
7eb95156 | 319 | write_lock(&nf_frags.lock); |
3140c25c | 320 | list_move_tail(&fq->q.lru_list, &nf_init_frags.lru_list); |
7eb95156 | 321 | write_unlock(&nf_frags.lock); |
9fb9cbb1 YK |
322 | return 0; |
323 | ||
1ee89bd0 ND |
324 | discard_fq: |
325 | fq_kill(fq); | |
9fb9cbb1 YK |
326 | err: |
327 | return -1; | |
328 | } | |
329 | ||
330 | /* | |
331 | * Check if this packet is complete. | |
332 | * Returns NULL on failure by any reason, and pointer | |
333 | * to current nexthdr field in reassembled frame. | |
334 | * | |
335 | * It is called with locked fq, and caller must check that | |
336 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
337 | * the last and the first frames arrived and all the bits are here. | |
338 | */ | |
339 | static struct sk_buff * | |
340 | nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev) | |
341 | { | |
5ab11c98 | 342 | struct sk_buff *fp, *op, *head = fq->q.fragments; |
9fb9cbb1 YK |
343 | int payload_len; |
344 | ||
345 | fq_kill(fq); | |
346 | ||
547b792c IJ |
347 | WARN_ON(head == NULL); |
348 | WARN_ON(NFCT_FRAG6_CB(head)->offset != 0); | |
9fb9cbb1 YK |
349 | |
350 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 351 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 352 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 353 | sizeof(struct frag_hdr)); |
9fb9cbb1 | 354 | if (payload_len > IPV6_MAXPLEN) { |
0d53778e | 355 | pr_debug("payload len is too large.\n"); |
9fb9cbb1 YK |
356 | goto out_oversize; |
357 | } | |
358 | ||
359 | /* Head of list must not be cloned. */ | |
360 | if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) { | |
0d53778e | 361 | pr_debug("skb is cloned but can't expand head"); |
9fb9cbb1 YK |
362 | goto out_oom; |
363 | } | |
364 | ||
365 | /* If the first fragment is fragmented itself, we split | |
366 | * it to two chunks: the first with data and paged part | |
367 | * and the second, holding only fragments. */ | |
21dc3301 | 368 | if (skb_has_frag_list(head)) { |
9fb9cbb1 YK |
369 | struct sk_buff *clone; |
370 | int i, plen = 0; | |
371 | ||
372 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) { | |
0d53778e | 373 | pr_debug("Can't alloc skb\n"); |
9fb9cbb1 YK |
374 | goto out_oom; |
375 | } | |
376 | clone->next = head->next; | |
377 | head->next = clone; | |
378 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
343a9972 | 379 | skb_frag_list_init(head); |
9fb9cbb1 YK |
380 | for (i=0; i<skb_shinfo(head)->nr_frags; i++) |
381 | plen += skb_shinfo(head)->frags[i].size; | |
382 | clone->len = clone->data_len = head->data_len - plen; | |
383 | head->data_len -= clone->len; | |
384 | head->len -= clone->len; | |
385 | clone->csum = 0; | |
386 | clone->ip_summed = head->ip_summed; | |
387 | ||
388 | NFCT_FRAG6_CB(clone)->orig = NULL; | |
6ddc0822 | 389 | atomic_add(clone->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
390 | } |
391 | ||
392 | /* We have to remove fragment header from datagram and to relocate | |
393 | * header in order to calculate ICV correctly. */ | |
bff9b61c | 394 | skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0]; |
1ab1457c | 395 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
9fb9cbb1 | 396 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
397 | head->mac_header += sizeof(struct frag_hdr); |
398 | head->network_header += sizeof(struct frag_hdr); | |
9fb9cbb1 YK |
399 | |
400 | skb_shinfo(head)->frag_list = head->next; | |
badff6d0 | 401 | skb_reset_transport_header(head); |
d56f90a7 | 402 | skb_push(head, head->data - skb_network_header(head)); |
9fb9cbb1 YK |
403 | |
404 | for (fp=head->next; fp; fp = fp->next) { | |
405 | head->data_len += fp->len; | |
406 | head->len += fp->len; | |
407 | if (head->ip_summed != fp->ip_summed) | |
408 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 409 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
9fb9cbb1 YK |
410 | head->csum = csum_add(head->csum, fp->csum); |
411 | head->truesize += fp->truesize; | |
9fb9cbb1 | 412 | } |
841a5940 | 413 | atomic_sub(head->truesize, &nf_init_frags.mem); |
9fb9cbb1 YK |
414 | |
415 | head->next = NULL; | |
416 | head->dev = dev; | |
5ab11c98 | 417 | head->tstamp = fq->q.stamp; |
0660e03f | 418 | ipv6_hdr(head)->payload_len = htons(payload_len); |
9fb9cbb1 YK |
419 | |
420 | /* Yes, and fold redundant checksum back. 8) */ | |
84fa7933 | 421 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 422 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 423 | skb_network_header_len(head), |
d56f90a7 | 424 | head->csum); |
9fb9cbb1 | 425 | |
5ab11c98 | 426 | fq->q.fragments = NULL; |
ea8fbe8f | 427 | fq->q.fragments_tail = NULL; |
9fb9cbb1 YK |
428 | |
429 | /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */ | |
430 | fp = skb_shinfo(head)->frag_list; | |
9e2dcf72 | 431 | if (fp && NFCT_FRAG6_CB(fp)->orig == NULL) |
9fb9cbb1 YK |
432 | /* at above code, head skb is divided into two skbs. */ |
433 | fp = fp->next; | |
434 | ||
435 | op = NFCT_FRAG6_CB(head)->orig; | |
436 | for (; fp; fp = fp->next) { | |
437 | struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig; | |
438 | ||
439 | op->next = orig; | |
440 | op = orig; | |
441 | NFCT_FRAG6_CB(fp)->orig = NULL; | |
442 | } | |
443 | ||
444 | return head; | |
445 | ||
446 | out_oversize: | |
447 | if (net_ratelimit()) | |
448 | printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len); | |
449 | goto out_fail; | |
450 | out_oom: | |
451 | if (net_ratelimit()) | |
452 | printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n"); | |
453 | out_fail: | |
454 | return NULL; | |
455 | } | |
456 | ||
457 | /* | |
458 | * find the header just before Fragment Header. | |
459 | * | |
460 | * if success return 0 and set ... | |
461 | * (*prevhdrp): the value of "Next Header Field" in the header | |
462 | * just before Fragment Header. | |
463 | * (*prevhoff): the offset of "Next Header Field" in the header | |
464 | * just before Fragment Header. | |
465 | * (*fhoff) : the offset of Fragment Header. | |
466 | * | |
467 | * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c | |
468 | * | |
469 | */ | |
470 | static int | |
471 | find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff) | |
472 | { | |
0660e03f | 473 | u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
6b88dd96 ACM |
474 | const int netoff = skb_network_offset(skb); |
475 | u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr); | |
476 | int start = netoff + sizeof(struct ipv6hdr); | |
9fb9cbb1 YK |
477 | int len = skb->len - start; |
478 | u8 prevhdr = NEXTHDR_IPV6; | |
479 | ||
1ab1457c YH |
480 | while (nexthdr != NEXTHDR_FRAGMENT) { |
481 | struct ipv6_opt_hdr hdr; | |
482 | int hdrlen; | |
9fb9cbb1 YK |
483 | |
484 | if (!ipv6_ext_hdr(nexthdr)) { | |
485 | return -1; | |
486 | } | |
1ab1457c | 487 | if (nexthdr == NEXTHDR_NONE) { |
0d53778e | 488 | pr_debug("next header is none\n"); |
9fb9cbb1 YK |
489 | return -1; |
490 | } | |
d1238d53 CP |
491 | if (len < (int)sizeof(struct ipv6_opt_hdr)) { |
492 | pr_debug("too short\n"); | |
493 | return -1; | |
494 | } | |
1ab1457c YH |
495 | if (skb_copy_bits(skb, start, &hdr, sizeof(hdr))) |
496 | BUG(); | |
497 | if (nexthdr == NEXTHDR_AUTH) | |
498 | hdrlen = (hdr.hdrlen+2)<<2; | |
499 | else | |
500 | hdrlen = ipv6_optlen(&hdr); | |
9fb9cbb1 YK |
501 | |
502 | prevhdr = nexthdr; | |
503 | prev_nhoff = start; | |
504 | ||
1ab1457c YH |
505 | nexthdr = hdr.nexthdr; |
506 | len -= hdrlen; | |
507 | start += hdrlen; | |
508 | } | |
9fb9cbb1 YK |
509 | |
510 | if (len < 0) | |
511 | return -1; | |
512 | ||
513 | *prevhdrp = prevhdr; | |
514 | *prevhoff = prev_nhoff; | |
515 | *fhoff = start; | |
516 | ||
517 | return 0; | |
518 | } | |
519 | ||
0b5ccb2e | 520 | struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user) |
9fb9cbb1 | 521 | { |
1ab1457c | 522 | struct sk_buff *clone; |
9fb9cbb1 YK |
523 | struct net_device *dev = skb->dev; |
524 | struct frag_hdr *fhdr; | |
525 | struct nf_ct_frag6_queue *fq; | |
526 | struct ipv6hdr *hdr; | |
527 | int fhoff, nhoff; | |
528 | u8 prevhdr; | |
529 | struct sk_buff *ret_skb = NULL; | |
530 | ||
531 | /* Jumbo payload inhibits frag. header */ | |
0660e03f | 532 | if (ipv6_hdr(skb)->payload_len == 0) { |
0d53778e | 533 | pr_debug("payload len = 0\n"); |
9fb9cbb1 YK |
534 | return skb; |
535 | } | |
536 | ||
537 | if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0) | |
538 | return skb; | |
539 | ||
540 | clone = skb_clone(skb, GFP_ATOMIC); | |
541 | if (clone == NULL) { | |
0d53778e | 542 | pr_debug("Can't clone skb\n"); |
9fb9cbb1 YK |
543 | return skb; |
544 | } | |
545 | ||
546 | NFCT_FRAG6_CB(clone)->orig = skb; | |
547 | ||
548 | if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) { | |
0d53778e | 549 | pr_debug("message is too short.\n"); |
9fb9cbb1 YK |
550 | goto ret_orig; |
551 | } | |
552 | ||
967b05f6 | 553 | skb_set_transport_header(clone, fhoff); |
0660e03f | 554 | hdr = ipv6_hdr(clone); |
bff9b61c | 555 | fhdr = (struct frag_hdr *)skb_transport_header(clone); |
9fb9cbb1 | 556 | |
e31e0bdc | 557 | if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh) |
9fb9cbb1 YK |
558 | nf_ct_frag6_evictor(); |
559 | ||
0b5ccb2e | 560 | fq = fq_find(fhdr->identification, user, &hdr->saddr, &hdr->daddr); |
9fb9cbb1 | 561 | if (fq == NULL) { |
0d53778e | 562 | pr_debug("Can't find and can't create new queue\n"); |
9fb9cbb1 YK |
563 | goto ret_orig; |
564 | } | |
565 | ||
b9c69896 | 566 | spin_lock_bh(&fq->q.lock); |
9fb9cbb1 YK |
567 | |
568 | if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) { | |
b9c69896 | 569 | spin_unlock_bh(&fq->q.lock); |
0d53778e | 570 | pr_debug("Can't insert skb to queue\n"); |
4b6cb5d8 | 571 | fq_put(fq); |
9fb9cbb1 YK |
572 | goto ret_orig; |
573 | } | |
574 | ||
bc578a54 JP |
575 | if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
576 | fq->q.meat == fq->q.len) { | |
9fb9cbb1 YK |
577 | ret_skb = nf_ct_frag6_reasm(fq, dev); |
578 | if (ret_skb == NULL) | |
0d53778e | 579 | pr_debug("Can't reassemble fragmented packets\n"); |
9fb9cbb1 | 580 | } |
b9c69896 | 581 | spin_unlock_bh(&fq->q.lock); |
9fb9cbb1 | 582 | |
4b6cb5d8 | 583 | fq_put(fq); |
9fb9cbb1 YK |
584 | return ret_skb; |
585 | ||
586 | ret_orig: | |
587 | kfree_skb(clone); | |
588 | return skb; | |
589 | } | |
590 | ||
591 | void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb, | |
592 | struct net_device *in, struct net_device *out, | |
593 | int (*okfn)(struct sk_buff *)) | |
594 | { | |
595 | struct sk_buff *s, *s2; | |
596 | ||
597 | for (s = NFCT_FRAG6_CB(skb)->orig; s;) { | |
598 | nf_conntrack_put_reasm(s->nfct_reasm); | |
599 | nf_conntrack_get_reasm(skb); | |
600 | s->nfct_reasm = skb; | |
601 | ||
602 | s2 = s->next; | |
f9f02cca PM |
603 | s->next = NULL; |
604 | ||
b2e0b385 | 605 | NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, s, in, out, okfn, |
9fb9cbb1 YK |
606 | NF_IP6_PRI_CONNTRACK_DEFRAG + 1); |
607 | s = s2; | |
608 | } | |
609 | nf_conntrack_put_reasm(skb); | |
610 | } | |
611 | ||
9fb9cbb1 YK |
612 | int nf_ct_frag6_init(void) |
613 | { | |
321a3a99 | 614 | nf_frags.hashfn = nf_hashfn; |
c6fda282 | 615 | nf_frags.constructor = ip6_frag_init; |
c9547709 | 616 | nf_frags.destructor = NULL; |
1e4b8287 PE |
617 | nf_frags.skb_free = nf_skb_free; |
618 | nf_frags.qsize = sizeof(struct nf_ct_frag6_queue); | |
abd6523d | 619 | nf_frags.match = ip6_frag_match; |
e521db9d | 620 | nf_frags.frag_expire = nf_ct_frag6_expire; |
3b4bc4a2 | 621 | nf_frags.secret_interval = 10 * 60 * HZ; |
b2fd5321 | 622 | nf_init_frags.timeout = IPV6_FRAG_TIMEOUT; |
7c070aa9 SW |
623 | nf_init_frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
624 | nf_init_frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
e5a2bb84 | 625 | inet_frags_init_net(&nf_init_frags); |
7eb95156 | 626 | inet_frags_init(&nf_frags); |
9fb9cbb1 | 627 | |
7932c2e5 | 628 | #ifdef CONFIG_SYSCTL |
e97c3e27 BS |
629 | nf_ct_frag6_sysctl_header = register_sysctl_paths(nf_net_netfilter_sysctl_path, |
630 | nf_ct_frag6_sysctl_table); | |
631 | if (!nf_ct_frag6_sysctl_header) { | |
632 | inet_frags_fini(&nf_frags); | |
633 | return -ENOMEM; | |
634 | } | |
7932c2e5 | 635 | #endif |
e97c3e27 | 636 | |
9fb9cbb1 YK |
637 | return 0; |
638 | } | |
639 | ||
640 | void nf_ct_frag6_cleanup(void) | |
641 | { | |
7932c2e5 | 642 | #ifdef CONFIG_SYSCTL |
e97c3e27 BS |
643 | unregister_sysctl_table(nf_ct_frag6_sysctl_header); |
644 | nf_ct_frag6_sysctl_header = NULL; | |
7932c2e5 | 645 | #endif |
7eb95156 PE |
646 | inet_frags_fini(&nf_frags); |
647 | ||
e31e0bdc | 648 | nf_init_frags.low_thresh = 0; |
9fb9cbb1 YK |
649 | nf_ct_frag6_evictor(); |
650 | } |