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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 | ||
5a3da1fe HFS |
17 | #define pr_fmt(fmt) "IPv6-nf: " fmt |
18 | ||
9fb9cbb1 YK |
19 | #include <linux/errno.h> |
20 | #include <linux/types.h> | |
21 | #include <linux/string.h> | |
22 | #include <linux/socket.h> | |
23 | #include <linux/sockios.h> | |
24 | #include <linux/jiffies.h> | |
25 | #include <linux/net.h> | |
26 | #include <linux/list.h> | |
27 | #include <linux/netdevice.h> | |
28 | #include <linux/in6.h> | |
29 | #include <linux/ipv6.h> | |
30 | #include <linux/icmpv6.h> | |
31 | #include <linux/random.h> | |
5a0e3ad6 | 32 | #include <linux/slab.h> |
9fb9cbb1 YK |
33 | |
34 | #include <net/sock.h> | |
35 | #include <net/snmp.h> | |
5ab11c98 | 36 | #include <net/inet_frag.h> |
9fb9cbb1 YK |
37 | |
38 | #include <net/ipv6.h> | |
39 | #include <net/protocol.h> | |
40 | #include <net/transp_v6.h> | |
41 | #include <net/rawv6.h> | |
42 | #include <net/ndisc.h> | |
43 | #include <net/addrconf.h> | |
b8dd6a22 | 44 | #include <net/inet_ecn.h> |
99fa5f53 | 45 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
9fb9cbb1 YK |
46 | #include <linux/sysctl.h> |
47 | #include <linux/netfilter.h> | |
48 | #include <linux/netfilter_ipv6.h> | |
49 | #include <linux/kernel.h> | |
50 | #include <linux/module.h> | |
bced94ed | 51 | #include <net/netfilter/ipv6/nf_defrag_ipv6.h> |
9fb9cbb1 | 52 | |
d4ad4d22 | 53 | static const char nf_frags_cache_name[] = "nf-frags"; |
9fb9cbb1 | 54 | |
9fb9cbb1 YK |
55 | struct nf_ct_frag6_skb_cb |
56 | { | |
57 | struct inet6_skb_parm h; | |
58 | int offset; | |
9fb9cbb1 YK |
59 | }; |
60 | ||
dbb526eb | 61 | #define NFCT_FRAG6_CB(skb) ((struct nf_ct_frag6_skb_cb *)((skb)->cb)) |
9fb9cbb1 | 62 | |
7eb95156 | 63 | static struct inet_frags nf_frags; |
9fb9cbb1 | 64 | |
8d8354d2 | 65 | #ifdef CONFIG_SYSCTL |
1bab4c75 NA |
66 | static int zero; |
67 | ||
be9e9163 | 68 | static struct ctl_table nf_ct_frag6_sysctl_table[] = { |
8d8354d2 PE |
69 | { |
70 | .procname = "nf_conntrack_frag6_timeout", | |
c038a767 | 71 | .data = &init_net.nf_frag.frags.timeout, |
8d8354d2 PE |
72 | .maxlen = sizeof(unsigned int), |
73 | .mode = 0644, | |
6d9f239a | 74 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
75 | }, |
76 | { | |
8d8354d2 | 77 | .procname = "nf_conntrack_frag6_low_thresh", |
c038a767 | 78 | .data = &init_net.nf_frag.frags.low_thresh, |
8d8354d2 PE |
79 | .maxlen = sizeof(unsigned int), |
80 | .mode = 0644, | |
1bab4c75 NA |
81 | .proc_handler = proc_dointvec_minmax, |
82 | .extra1 = &zero, | |
83 | .extra2 = &init_net.nf_frag.frags.high_thresh | |
8d8354d2 PE |
84 | }, |
85 | { | |
8d8354d2 | 86 | .procname = "nf_conntrack_frag6_high_thresh", |
c038a767 | 87 | .data = &init_net.nf_frag.frags.high_thresh, |
8d8354d2 PE |
88 | .maxlen = sizeof(unsigned int), |
89 | .mode = 0644, | |
1bab4c75 NA |
90 | .proc_handler = proc_dointvec_minmax, |
91 | .extra1 = &init_net.nf_frag.frags.low_thresh | |
8d8354d2 | 92 | }, |
f8572d8f | 93 | { } |
8d8354d2 | 94 | }; |
e97c3e27 | 95 | |
f1df1374 | 96 | static int nf_ct_frag6_sysctl_register(struct net *net) |
c038a767 AW |
97 | { |
98 | struct ctl_table *table; | |
99 | struct ctl_table_header *hdr; | |
100 | ||
101 | table = nf_ct_frag6_sysctl_table; | |
102 | if (!net_eq(net, &init_net)) { | |
103 | table = kmemdup(table, sizeof(nf_ct_frag6_sysctl_table), | |
104 | GFP_KERNEL); | |
105 | if (table == NULL) | |
106 | goto err_alloc; | |
107 | ||
894e2ac8 MK |
108 | table[0].data = &net->nf_frag.frags.timeout; |
109 | table[1].data = &net->nf_frag.frags.low_thresh; | |
1bab4c75 | 110 | table[1].extra2 = &net->nf_frag.frags.high_thresh; |
894e2ac8 | 111 | table[2].data = &net->nf_frag.frags.high_thresh; |
1bab4c75 NA |
112 | table[2].extra1 = &net->nf_frag.frags.low_thresh; |
113 | table[2].extra2 = &init_net.nf_frag.frags.high_thresh; | |
c038a767 AW |
114 | } |
115 | ||
116 | hdr = register_net_sysctl(net, "net/netfilter", table); | |
117 | if (hdr == NULL) | |
118 | goto err_reg; | |
119 | ||
4b7cc7fc | 120 | net->nf_frag.sysctl.frags_hdr = hdr; |
c038a767 AW |
121 | return 0; |
122 | ||
123 | err_reg: | |
124 | if (!net_eq(net, &init_net)) | |
125 | kfree(table); | |
126 | err_alloc: | |
127 | return -ENOMEM; | |
128 | } | |
129 | ||
130 | static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net) | |
131 | { | |
132 | struct ctl_table *table; | |
133 | ||
134 | table = net->nf_frag.sysctl.frags_hdr->ctl_table_arg; | |
135 | unregister_net_sysctl_table(net->nf_frag.sysctl.frags_hdr); | |
136 | if (!net_eq(net, &init_net)) | |
137 | kfree(table); | |
138 | } | |
139 | ||
140 | #else | |
f1df1374 | 141 | static int nf_ct_frag6_sysctl_register(struct net *net) |
c038a767 AW |
142 | { |
143 | return 0; | |
144 | } | |
145 | static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net) | |
146 | { | |
147 | } | |
8d8354d2 PE |
148 | #endif |
149 | ||
b8dd6a22 HFS |
150 | static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) |
151 | { | |
152 | return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); | |
153 | } | |
154 | ||
b1190570 HFS |
155 | static unsigned int nf_hash_frag(__be32 id, const struct in6_addr *saddr, |
156 | const struct in6_addr *daddr) | |
157 | { | |
b1190570 | 158 | net_get_random_once(&nf_frags.rnd, sizeof(nf_frags.rnd)); |
fb3cfe6e FW |
159 | return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), |
160 | (__force u32)id, nf_frags.rnd); | |
b1190570 HFS |
161 | } |
162 | ||
163 | ||
36c77782 | 164 | static unsigned int nf_hashfn(const struct inet_frag_queue *q) |
9fb9cbb1 | 165 | { |
b836c99f | 166 | const struct frag_queue *nq; |
9fb9cbb1 | 167 | |
b836c99f | 168 | nq = container_of(q, struct frag_queue, q); |
b1190570 | 169 | return nf_hash_frag(nq->id, &nq->saddr, &nq->daddr); |
9fb9cbb1 YK |
170 | } |
171 | ||
9fb9cbb1 YK |
172 | static void nf_ct_frag6_expire(unsigned long data) |
173 | { | |
b836c99f AW |
174 | struct frag_queue *fq; |
175 | struct net *net; | |
9fb9cbb1 | 176 | |
b836c99f AW |
177 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); |
178 | net = container_of(fq->q.net, struct net, nf_frag.frags); | |
9fb9cbb1 | 179 | |
b836c99f | 180 | ip6_expire_frag_queue(net, fq, &nf_frags); |
9fb9cbb1 YK |
181 | } |
182 | ||
183 | /* Creation primitives. */ | |
b836c99f AW |
184 | static inline struct frag_queue *fq_find(struct net *net, __be32 id, |
185 | u32 user, struct in6_addr *src, | |
264640fc | 186 | struct in6_addr *dst, int iif, u8 ecn) |
9fb9cbb1 | 187 | { |
2588fe1d | 188 | struct inet_frag_queue *q; |
c6fda282 | 189 | struct ip6_create_arg arg; |
abd6523d | 190 | unsigned int hash; |
9fb9cbb1 | 191 | |
c6fda282 | 192 | arg.id = id; |
0b5ccb2e | 193 | arg.user = user; |
c6fda282 PE |
194 | arg.src = src; |
195 | arg.dst = dst; | |
264640fc | 196 | arg.iif = iif; |
b8dd6a22 | 197 | arg.ecn = ecn; |
9a375803 | 198 | |
ab1c724f | 199 | local_bh_disable(); |
b1190570 | 200 | hash = nf_hash_frag(id, src, dst); |
9fb9cbb1 | 201 | |
c038a767 | 202 | q = inet_frag_find(&net->nf_frag.frags, &nf_frags, &arg, hash); |
b9c69896 | 203 | local_bh_enable(); |
5a3da1fe HFS |
204 | if (IS_ERR_OR_NULL(q)) { |
205 | inet_frag_maybe_warn_overflow(q, pr_fmt()); | |
206 | return NULL; | |
207 | } | |
b836c99f | 208 | return container_of(q, struct frag_queue, q); |
9fb9cbb1 YK |
209 | } |
210 | ||
9fb9cbb1 | 211 | |
b836c99f | 212 | static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb, |
58c0fb0d | 213 | const struct frag_hdr *fhdr, int nhoff) |
9fb9cbb1 YK |
214 | { |
215 | struct sk_buff *prev, *next; | |
4cdd3408 | 216 | unsigned int payload_len; |
9fb9cbb1 | 217 | int offset, end; |
b8dd6a22 | 218 | u8 ecn; |
9fb9cbb1 | 219 | |
06aa8b8a | 220 | if (fq->q.flags & INET_FRAG_COMPLETE) { |
698f9315 | 221 | pr_debug("Already completed\n"); |
9fb9cbb1 YK |
222 | goto err; |
223 | } | |
224 | ||
4cdd3408 PM |
225 | payload_len = ntohs(ipv6_hdr(skb)->payload_len); |
226 | ||
9fb9cbb1 | 227 | offset = ntohs(fhdr->frag_off) & ~0x7; |
4cdd3408 | 228 | end = offset + (payload_len - |
0660e03f | 229 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); |
9fb9cbb1 YK |
230 | |
231 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
0d53778e | 232 | pr_debug("offset is too large.\n"); |
1ab1457c | 233 | return -1; |
9fb9cbb1 YK |
234 | } |
235 | ||
b8dd6a22 HFS |
236 | ecn = ip6_frag_ecn(ipv6_hdr(skb)); |
237 | ||
d56f90a7 ACM |
238 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
239 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 240 | skb->csum = csum_sub(skb->csum, |
d56f90a7 | 241 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
9fb9cbb1 | 242 | 0)); |
d56f90a7 | 243 | } |
9fb9cbb1 YK |
244 | |
245 | /* Is this the final fragment? */ | |
246 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
247 | /* If we already have some bits beyond end | |
248 | * or have different end, the segment is corrupted. | |
249 | */ | |
5ab11c98 | 250 | if (end < fq->q.len || |
06aa8b8a | 251 | ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) { |
0d53778e | 252 | pr_debug("already received last fragment\n"); |
9fb9cbb1 YK |
253 | goto err; |
254 | } | |
06aa8b8a | 255 | fq->q.flags |= INET_FRAG_LAST_IN; |
5ab11c98 | 256 | fq->q.len = end; |
9fb9cbb1 YK |
257 | } else { |
258 | /* Check if the fragment is rounded to 8 bytes. | |
259 | * Required by the RFC. | |
260 | */ | |
261 | if (end & 0x7) { | |
262 | /* RFC2460 says always send parameter problem in | |
263 | * this case. -DaveM | |
264 | */ | |
0d53778e | 265 | pr_debug("end of fragment not rounded to 8 bytes.\n"); |
9fb9cbb1 YK |
266 | return -1; |
267 | } | |
5ab11c98 | 268 | if (end > fq->q.len) { |
9fb9cbb1 | 269 | /* Some bits beyond end -> corruption. */ |
06aa8b8a | 270 | if (fq->q.flags & INET_FRAG_LAST_IN) { |
0d53778e | 271 | pr_debug("last packet already reached.\n"); |
9fb9cbb1 YK |
272 | goto err; |
273 | } | |
5ab11c98 | 274 | fq->q.len = end; |
9fb9cbb1 YK |
275 | } |
276 | } | |
277 | ||
278 | if (end == offset) | |
279 | goto err; | |
280 | ||
281 | /* Point into the IP datagram 'data' part. */ | |
282 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) { | |
0d53778e | 283 | pr_debug("queue: message is too short.\n"); |
9fb9cbb1 YK |
284 | goto err; |
285 | } | |
b38dfee3 | 286 | if (pskb_trim_rcsum(skb, end - offset)) { |
0d53778e | 287 | pr_debug("Can't trim\n"); |
b38dfee3 | 288 | goto err; |
9fb9cbb1 YK |
289 | } |
290 | ||
291 | /* Find out which fragments are in front and at the back of us | |
292 | * in the chain of fragments so far. We must know where to put | |
293 | * this fragment, right? | |
294 | */ | |
ea8fbe8f CG |
295 | prev = fq->q.fragments_tail; |
296 | if (!prev || NFCT_FRAG6_CB(prev)->offset < offset) { | |
297 | next = NULL; | |
298 | goto found; | |
299 | } | |
9fb9cbb1 | 300 | prev = NULL; |
5ab11c98 | 301 | for (next = fq->q.fragments; next != NULL; next = next->next) { |
9fb9cbb1 YK |
302 | if (NFCT_FRAG6_CB(next)->offset >= offset) |
303 | break; /* bingo! */ | |
304 | prev = next; | |
305 | } | |
306 | ||
ea8fbe8f | 307 | found: |
1ee89bd0 ND |
308 | /* RFC5722, Section 4: |
309 | * When reassembling an IPv6 datagram, if | |
310 | * one or more its constituent fragments is determined to be an | |
311 | * overlapping fragment, the entire datagram (and any constituent | |
312 | * fragments, including those not yet received) MUST be silently | |
313 | * discarded. | |
9fb9cbb1 | 314 | */ |
9fb9cbb1 | 315 | |
1ee89bd0 ND |
316 | /* Check for overlap with preceding fragment. */ |
317 | if (prev && | |
22e091e5 | 318 | (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset) |
1ee89bd0 | 319 | goto discard_fq; |
9fb9cbb1 | 320 | |
1ee89bd0 ND |
321 | /* Look for overlap with succeeding segment. */ |
322 | if (next && NFCT_FRAG6_CB(next)->offset < end) | |
323 | goto discard_fq; | |
9fb9cbb1 YK |
324 | |
325 | NFCT_FRAG6_CB(skb)->offset = offset; | |
326 | ||
327 | /* Insert this fragment in the chain of fragments. */ | |
328 | skb->next = next; | |
ea8fbe8f CG |
329 | if (!next) |
330 | fq->q.fragments_tail = skb; | |
9fb9cbb1 YK |
331 | if (prev) |
332 | prev->next = skb; | |
333 | else | |
5ab11c98 | 334 | fq->q.fragments = skb; |
9fb9cbb1 | 335 | |
97cf00e9 HX |
336 | if (skb->dev) { |
337 | fq->iif = skb->dev->ifindex; | |
338 | skb->dev = NULL; | |
339 | } | |
5ab11c98 PE |
340 | fq->q.stamp = skb->tstamp; |
341 | fq->q.meat += skb->len; | |
b8dd6a22 | 342 | fq->ecn |= ecn; |
4cdd3408 PM |
343 | if (payload_len > fq->q.max_size) |
344 | fq->q.max_size = payload_len; | |
0e60d245 | 345 | add_frag_mem_limit(fq->q.net, skb->truesize); |
9fb9cbb1 YK |
346 | |
347 | /* The first fragment. | |
348 | * nhoffset is obtained from the first fragment, of course. | |
349 | */ | |
350 | if (offset == 0) { | |
351 | fq->nhoffset = nhoff; | |
06aa8b8a | 352 | fq->q.flags |= INET_FRAG_FIRST_IN; |
9fb9cbb1 | 353 | } |
3ef0eb0d | 354 | |
9fb9cbb1 YK |
355 | return 0; |
356 | ||
1ee89bd0 | 357 | discard_fq: |
b836c99f | 358 | inet_frag_kill(&fq->q, &nf_frags); |
9fb9cbb1 YK |
359 | err: |
360 | return -1; | |
361 | } | |
362 | ||
363 | /* | |
364 | * Check if this packet is complete. | |
9fb9cbb1 YK |
365 | * |
366 | * It is called with locked fq, and caller must check that | |
367 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
368 | * the last and the first frames arrived and all the bits are here. | |
daaa7d64 FW |
369 | * |
370 | * returns true if *prev skb has been transformed into the reassembled | |
371 | * skb, false otherwise. | |
9fb9cbb1 | 372 | */ |
daaa7d64 | 373 | static bool |
029f7f3b | 374 | nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_device *dev) |
9fb9cbb1 | 375 | { |
029f7f3b | 376 | struct sk_buff *fp, *head = fq->q.fragments; |
9fb9cbb1 | 377 | int payload_len; |
b8dd6a22 | 378 | u8 ecn; |
9fb9cbb1 | 379 | |
b836c99f | 380 | inet_frag_kill(&fq->q, &nf_frags); |
9fb9cbb1 | 381 | |
547b792c IJ |
382 | WARN_ON(head == NULL); |
383 | WARN_ON(NFCT_FRAG6_CB(head)->offset != 0); | |
9fb9cbb1 | 384 | |
b8dd6a22 HFS |
385 | ecn = ip_frag_ecn_table[fq->ecn]; |
386 | if (unlikely(ecn == 0xff)) | |
daaa7d64 | 387 | return false; |
b8dd6a22 | 388 | |
9fb9cbb1 | 389 | /* Unfragmented part is taken from the first segment. */ |
d56f90a7 | 390 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 391 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 392 | sizeof(struct frag_hdr)); |
9fb9cbb1 | 393 | if (payload_len > IPV6_MAXPLEN) { |
daaa7d64 FW |
394 | net_dbg_ratelimited("nf_ct_frag6_reasm: payload len = %d\n", |
395 | payload_len); | |
396 | return false; | |
9fb9cbb1 YK |
397 | } |
398 | ||
399 | /* Head of list must not be cloned. */ | |
daaa7d64 FW |
400 | if (skb_unclone(head, GFP_ATOMIC)) |
401 | return false; | |
9fb9cbb1 YK |
402 | |
403 | /* If the first fragment is fragmented itself, we split | |
404 | * it to two chunks: the first with data and paged part | |
405 | * and the second, holding only fragments. */ | |
21dc3301 | 406 | if (skb_has_frag_list(head)) { |
9fb9cbb1 YK |
407 | struct sk_buff *clone; |
408 | int i, plen = 0; | |
409 | ||
0a9ee813 JP |
410 | clone = alloc_skb(0, GFP_ATOMIC); |
411 | if (clone == NULL) | |
daaa7d64 | 412 | return false; |
0a9ee813 | 413 | |
9fb9cbb1 YK |
414 | clone->next = head->next; |
415 | head->next = clone; | |
416 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
343a9972 | 417 | skb_frag_list_init(head); |
9e903e08 ED |
418 | for (i = 0; i < skb_shinfo(head)->nr_frags; i++) |
419 | plen += skb_frag_size(&skb_shinfo(head)->frags[i]); | |
9fb9cbb1 YK |
420 | clone->len = clone->data_len = head->data_len - plen; |
421 | head->data_len -= clone->len; | |
422 | head->len -= clone->len; | |
423 | clone->csum = 0; | |
424 | clone->ip_summed = head->ip_summed; | |
425 | ||
0e60d245 | 426 | add_frag_mem_limit(fq->q.net, clone->truesize); |
9fb9cbb1 YK |
427 | } |
428 | ||
029f7f3b FW |
429 | /* morph head into last received skb: prev. |
430 | * | |
431 | * This allows callers of ipv6 conntrack defrag to continue | |
432 | * to use the last skb(frag) passed into the reasm engine. | |
433 | * The last skb frag 'silently' turns into the full reassembled skb. | |
434 | * | |
435 | * Since prev is also part of q->fragments we have to clone it first. | |
436 | */ | |
437 | if (head != prev) { | |
438 | struct sk_buff *iter; | |
439 | ||
440 | fp = skb_clone(prev, GFP_ATOMIC); | |
441 | if (!fp) | |
daaa7d64 | 442 | return false; |
029f7f3b FW |
443 | |
444 | fp->next = prev->next; | |
e97ac128 FW |
445 | |
446 | iter = head; | |
447 | while (iter) { | |
448 | if (iter->next == prev) { | |
449 | iter->next = fp; | |
450 | break; | |
451 | } | |
452 | iter = iter->next; | |
029f7f3b FW |
453 | } |
454 | ||
455 | skb_morph(prev, head); | |
456 | prev->next = head->next; | |
457 | consume_skb(head); | |
458 | head = prev; | |
459 | } | |
460 | ||
9fb9cbb1 YK |
461 | /* We have to remove fragment header from datagram and to relocate |
462 | * header in order to calculate ICV correctly. */ | |
bff9b61c | 463 | skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0]; |
1ab1457c | 464 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
9fb9cbb1 | 465 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
466 | head->mac_header += sizeof(struct frag_hdr); |
467 | head->network_header += sizeof(struct frag_hdr); | |
9fb9cbb1 YK |
468 | |
469 | skb_shinfo(head)->frag_list = head->next; | |
badff6d0 | 470 | skb_reset_transport_header(head); |
d56f90a7 | 471 | skb_push(head, head->data - skb_network_header(head)); |
9fb9cbb1 | 472 | |
f9527ea9 | 473 | for (fp = head->next; fp; fp = fp->next) { |
9fb9cbb1 YK |
474 | head->data_len += fp->len; |
475 | head->len += fp->len; | |
476 | if (head->ip_summed != fp->ip_summed) | |
477 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 478 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
9fb9cbb1 YK |
479 | head->csum = csum_add(head->csum, fp->csum); |
480 | head->truesize += fp->truesize; | |
9fb9cbb1 | 481 | } |
0e60d245 | 482 | sub_frag_mem_limit(fq->q.net, head->truesize); |
9fb9cbb1 | 483 | |
60ff7467 | 484 | head->ignore_df = 1; |
9fb9cbb1 YK |
485 | head->next = NULL; |
486 | head->dev = dev; | |
5ab11c98 | 487 | head->tstamp = fq->q.stamp; |
0660e03f | 488 | ipv6_hdr(head)->payload_len = htons(payload_len); |
b8dd6a22 | 489 | ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); |
4cdd3408 | 490 | IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size; |
9fb9cbb1 YK |
491 | |
492 | /* Yes, and fold redundant checksum back. 8) */ | |
84fa7933 | 493 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 494 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 495 | skb_network_header_len(head), |
d56f90a7 | 496 | head->csum); |
9fb9cbb1 | 497 | |
5ab11c98 | 498 | fq->q.fragments = NULL; |
ea8fbe8f | 499 | fq->q.fragments_tail = NULL; |
9fb9cbb1 | 500 | |
daaa7d64 | 501 | return true; |
9fb9cbb1 YK |
502 | } |
503 | ||
504 | /* | |
505 | * find the header just before Fragment Header. | |
506 | * | |
507 | * if success return 0 and set ... | |
508 | * (*prevhdrp): the value of "Next Header Field" in the header | |
509 | * just before Fragment Header. | |
510 | * (*prevhoff): the offset of "Next Header Field" in the header | |
511 | * just before Fragment Header. | |
512 | * (*fhoff) : the offset of Fragment Header. | |
513 | * | |
514 | * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c | |
515 | * | |
516 | */ | |
517 | static int | |
518 | find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff) | |
519 | { | |
0660e03f | 520 | u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
6b88dd96 ACM |
521 | const int netoff = skb_network_offset(skb); |
522 | u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr); | |
523 | int start = netoff + sizeof(struct ipv6hdr); | |
9fb9cbb1 YK |
524 | int len = skb->len - start; |
525 | u8 prevhdr = NEXTHDR_IPV6; | |
526 | ||
1ab1457c YH |
527 | while (nexthdr != NEXTHDR_FRAGMENT) { |
528 | struct ipv6_opt_hdr hdr; | |
529 | int hdrlen; | |
9fb9cbb1 YK |
530 | |
531 | if (!ipv6_ext_hdr(nexthdr)) { | |
532 | return -1; | |
533 | } | |
1ab1457c | 534 | if (nexthdr == NEXTHDR_NONE) { |
0d53778e | 535 | pr_debug("next header is none\n"); |
9fb9cbb1 YK |
536 | return -1; |
537 | } | |
d1238d53 CP |
538 | if (len < (int)sizeof(struct ipv6_opt_hdr)) { |
539 | pr_debug("too short\n"); | |
540 | return -1; | |
541 | } | |
1ab1457c YH |
542 | if (skb_copy_bits(skb, start, &hdr, sizeof(hdr))) |
543 | BUG(); | |
544 | if (nexthdr == NEXTHDR_AUTH) | |
545 | hdrlen = (hdr.hdrlen+2)<<2; | |
546 | else | |
547 | hdrlen = ipv6_optlen(&hdr); | |
9fb9cbb1 YK |
548 | |
549 | prevhdr = nexthdr; | |
550 | prev_nhoff = start; | |
551 | ||
1ab1457c YH |
552 | nexthdr = hdr.nexthdr; |
553 | len -= hdrlen; | |
554 | start += hdrlen; | |
555 | } | |
9fb9cbb1 YK |
556 | |
557 | if (len < 0) | |
558 | return -1; | |
559 | ||
560 | *prevhdrp = prevhdr; | |
561 | *prevhoff = prev_nhoff; | |
562 | *fhoff = start; | |
563 | ||
564 | return 0; | |
565 | } | |
566 | ||
daaa7d64 | 567 | int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user) |
9fb9cbb1 | 568 | { |
9fb9cbb1 | 569 | struct net_device *dev = skb->dev; |
daaa7d64 | 570 | int fhoff, nhoff, ret; |
9fb9cbb1 | 571 | struct frag_hdr *fhdr; |
b836c99f | 572 | struct frag_queue *fq; |
9fb9cbb1 | 573 | struct ipv6hdr *hdr; |
9fb9cbb1 | 574 | u8 prevhdr; |
9fb9cbb1 YK |
575 | |
576 | /* Jumbo payload inhibits frag. header */ | |
0660e03f | 577 | if (ipv6_hdr(skb)->payload_len == 0) { |
0d53778e | 578 | pr_debug("payload len = 0\n"); |
daaa7d64 | 579 | return -EINVAL; |
9fb9cbb1 YK |
580 | } |
581 | ||
582 | if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0) | |
daaa7d64 | 583 | return -EINVAL; |
9fb9cbb1 | 584 | |
029f7f3b | 585 | if (!pskb_may_pull(skb, fhoff + sizeof(*fhdr))) |
daaa7d64 | 586 | return -ENOMEM; |
9fb9cbb1 | 587 | |
029f7f3b FW |
588 | skb_set_transport_header(skb, fhoff); |
589 | hdr = ipv6_hdr(skb); | |
590 | fhdr = (struct frag_hdr *)skb_transport_header(skb); | |
9fb9cbb1 | 591 | |
b8dd6a22 | 592 | fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr, |
264640fc | 593 | skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); |
9fb9cbb1 | 594 | if (fq == NULL) { |
0d53778e | 595 | pr_debug("Can't find and can't create new queue\n"); |
daaa7d64 | 596 | return -ENOMEM; |
9fb9cbb1 YK |
597 | } |
598 | ||
b9c69896 | 599 | spin_lock_bh(&fq->q.lock); |
9fb9cbb1 | 600 | |
029f7f3b | 601 | if (nf_ct_frag6_queue(fq, skb, fhdr, nhoff) < 0) { |
daaa7d64 FW |
602 | ret = -EINVAL; |
603 | goto out_unlock; | |
9fb9cbb1 YK |
604 | } |
605 | ||
daaa7d64 FW |
606 | /* after queue has assumed skb ownership, only 0 or -EINPROGRESS |
607 | * must be returned. | |
608 | */ | |
609 | ret = -EINPROGRESS; | |
06aa8b8a | 610 | if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
daaa7d64 FW |
611 | fq->q.meat == fq->q.len && |
612 | nf_ct_frag6_reasm(fq, skb, dev)) | |
613 | ret = 0; | |
9fb9cbb1 | 614 | |
daaa7d64 FW |
615 | out_unlock: |
616 | spin_unlock_bh(&fq->q.lock); | |
b836c99f | 617 | inet_frag_put(&fq->q, &nf_frags); |
daaa7d64 | 618 | return ret; |
9fb9cbb1 | 619 | } |
5b490047 | 620 | EXPORT_SYMBOL_GPL(nf_ct_frag6_gather); |
9fb9cbb1 | 621 | |
c038a767 AW |
622 | static int nf_ct_net_init(struct net *net) |
623 | { | |
1d6119ba ED |
624 | int res; |
625 | ||
c038a767 AW |
626 | net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
627 | net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
628 | net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT; | |
1d6119ba ED |
629 | res = inet_frags_init_net(&net->nf_frag.frags); |
630 | if (res) | |
631 | return res; | |
632 | res = nf_ct_frag6_sysctl_register(net); | |
633 | if (res) | |
634 | inet_frags_uninit_net(&net->nf_frag.frags); | |
635 | return res; | |
c038a767 AW |
636 | } |
637 | ||
638 | static void nf_ct_net_exit(struct net *net) | |
639 | { | |
640 | nf_ct_frags6_sysctl_unregister(net); | |
641 | inet_frags_exit_net(&net->nf_frag.frags, &nf_frags); | |
642 | } | |
643 | ||
644 | static struct pernet_operations nf_ct_net_ops = { | |
645 | .init = nf_ct_net_init, | |
646 | .exit = nf_ct_net_exit, | |
647 | }; | |
648 | ||
9fb9cbb1 YK |
649 | int nf_ct_frag6_init(void) |
650 | { | |
c038a767 AW |
651 | int ret = 0; |
652 | ||
321a3a99 | 653 | nf_frags.hashfn = nf_hashfn; |
c6fda282 | 654 | nf_frags.constructor = ip6_frag_init; |
c9547709 | 655 | nf_frags.destructor = NULL; |
b836c99f | 656 | nf_frags.qsize = sizeof(struct frag_queue); |
abd6523d | 657 | nf_frags.match = ip6_frag_match; |
e521db9d | 658 | nf_frags.frag_expire = nf_ct_frag6_expire; |
d4ad4d22 NA |
659 | nf_frags.frags_cache_name = nf_frags_cache_name; |
660 | ret = inet_frags_init(&nf_frags); | |
661 | if (ret) | |
662 | goto out; | |
c038a767 AW |
663 | ret = register_pernet_subsys(&nf_ct_net_ops); |
664 | if (ret) | |
e97c3e27 | 665 | inet_frags_fini(&nf_frags); |
e97c3e27 | 666 | |
d4ad4d22 | 667 | out: |
c038a767 | 668 | return ret; |
9fb9cbb1 YK |
669 | } |
670 | ||
671 | void nf_ct_frag6_cleanup(void) | |
672 | { | |
c038a767 | 673 | unregister_pernet_subsys(&nf_ct_net_ops); |
7eb95156 | 674 | inet_frags_fini(&nf_frags); |
9fb9cbb1 | 675 | } |