Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * IPv6 fragment reassembly | |
1ab1457c | 3 | * Linux INET6 implementation |
1da177e4 LT |
4 | * |
5 | * Authors: | |
1ab1457c | 6 | * Pedro Roque <roque@di.fc.ul.pt> |
1da177e4 | 7 | * |
1da177e4 LT |
8 | * Based on: net/ipv4/ip_fragment.c |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version | |
13 | * 2 of the License, or (at your option) any later version. | |
14 | */ | |
15 | ||
1ab1457c YH |
16 | /* |
17 | * Fixes: | |
1da177e4 LT |
18 | * Andi Kleen Make it work with multiple hosts. |
19 | * More RFC compliance. | |
20 | * | |
21 | * Horst von Brand Add missing #include <linux/string.h> | |
22 | * Alexey Kuznetsov SMP races, threading, cleanup. | |
23 | * Patrick McHardy LRU queue of frag heads for evictor. | |
24 | * Mitsuru KANDA @USAGI Register inet6_protocol{}. | |
25 | * David Stevens and | |
26 | * YOSHIFUJI,H. @USAGI Always remove fragment header to | |
27 | * calculate ICV correctly. | |
28 | */ | |
5a3da1fe HFS |
29 | |
30 | #define pr_fmt(fmt) "IPv6: " fmt | |
31 | ||
1da177e4 LT |
32 | #include <linux/errno.h> |
33 | #include <linux/types.h> | |
34 | #include <linux/string.h> | |
35 | #include <linux/socket.h> | |
36 | #include <linux/sockios.h> | |
37 | #include <linux/jiffies.h> | |
38 | #include <linux/net.h> | |
39 | #include <linux/list.h> | |
40 | #include <linux/netdevice.h> | |
41 | #include <linux/in6.h> | |
42 | #include <linux/ipv6.h> | |
43 | #include <linux/icmpv6.h> | |
44 | #include <linux/random.h> | |
45 | #include <linux/jhash.h> | |
f61944ef | 46 | #include <linux/skbuff.h> |
5a0e3ad6 | 47 | #include <linux/slab.h> |
bc3b2d7f | 48 | #include <linux/export.h> |
1da177e4 LT |
49 | |
50 | #include <net/sock.h> | |
51 | #include <net/snmp.h> | |
52 | ||
53 | #include <net/ipv6.h> | |
a11d206d | 54 | #include <net/ip6_route.h> |
1da177e4 LT |
55 | #include <net/protocol.h> |
56 | #include <net/transp_v6.h> | |
57 | #include <net/rawv6.h> | |
58 | #include <net/ndisc.h> | |
59 | #include <net/addrconf.h> | |
5ab11c98 | 60 | #include <net/inet_frag.h> |
eec2e618 | 61 | #include <net/inet_ecn.h> |
1da177e4 | 62 | |
d4ad4d22 NA |
63 | static const char ip6_frag_cache_name[] = "ip6-frags"; |
64 | ||
cc24beca | 65 | struct ip6frag_skb_cb { |
1da177e4 LT |
66 | struct inet6_skb_parm h; |
67 | int offset; | |
68 | }; | |
69 | ||
67ba4152 | 70 | #define FRAG6_CB(skb) ((struct ip6frag_skb_cb *)((skb)->cb)) |
1da177e4 | 71 | |
fc08c258 | 72 | static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) |
eec2e618 HFS |
73 | { |
74 | return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); | |
75 | } | |
1da177e4 | 76 | |
7eb95156 | 77 | static struct inet_frags ip6_frags; |
1da177e4 | 78 | |
f61944ef HX |
79 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
80 | struct net_device *dev); | |
81 | ||
f6596f9d ZB |
82 | /* |
83 | * callers should be careful not to use the hash value outside the ipfrag_lock | |
84 | * as doing so could race with ipfrag_hash_rnd being recalculated. | |
85 | */ | |
b1190570 HFS |
86 | static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, |
87 | const struct in6_addr *daddr) | |
1da177e4 | 88 | { |
b1190570 | 89 | net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); |
fb3cfe6e FW |
90 | return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), |
91 | (__force u32)id, ip6_frags.rnd); | |
1da177e4 LT |
92 | } |
93 | ||
36c77782 | 94 | static unsigned int ip6_hashfn(const struct inet_frag_queue *q) |
1da177e4 | 95 | { |
36c77782 | 96 | const struct frag_queue *fq; |
1da177e4 | 97 | |
321a3a99 | 98 | fq = container_of(q, struct frag_queue, q); |
b1190570 | 99 | return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr); |
1da177e4 LT |
100 | } |
101 | ||
36c77782 | 102 | bool ip6_frag_match(const struct inet_frag_queue *q, const void *a) |
abd6523d | 103 | { |
36c77782 FW |
104 | const struct frag_queue *fq; |
105 | const struct ip6_create_arg *arg = a; | |
abd6523d PE |
106 | |
107 | fq = container_of(q, struct frag_queue, q); | |
cbc264ca ED |
108 | return fq->id == arg->id && |
109 | fq->user == arg->user && | |
110 | ipv6_addr_equal(&fq->saddr, arg->src) && | |
264640fc MK |
111 | ipv6_addr_equal(&fq->daddr, arg->dst) && |
112 | (arg->iif == fq->iif || | |
113 | !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST | | |
114 | IPV6_ADDR_LINKLOCAL))); | |
abd6523d PE |
115 | } |
116 | EXPORT_SYMBOL(ip6_frag_match); | |
117 | ||
36c77782 | 118 | void ip6_frag_init(struct inet_frag_queue *q, const void *a) |
1da177e4 | 119 | { |
c6fda282 | 120 | struct frag_queue *fq = container_of(q, struct frag_queue, q); |
36c77782 | 121 | const struct ip6_create_arg *arg = a; |
c6fda282 PE |
122 | |
123 | fq->id = arg->id; | |
0b5ccb2e | 124 | fq->user = arg->user; |
4e3fd7a0 AD |
125 | fq->saddr = *arg->src; |
126 | fq->daddr = *arg->dst; | |
eec2e618 | 127 | fq->ecn = arg->ecn; |
1da177e4 | 128 | } |
c6fda282 | 129 | EXPORT_SYMBOL(ip6_frag_init); |
1da177e4 | 130 | |
b836c99f AW |
131 | void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, |
132 | struct inet_frags *frags) | |
1da177e4 | 133 | { |
a11d206d | 134 | struct net_device *dev = NULL; |
e521db9d | 135 | |
5ab11c98 | 136 | spin_lock(&fq->q.lock); |
1da177e4 | 137 | |
06aa8b8a | 138 | if (fq->q.flags & INET_FRAG_COMPLETE) |
1da177e4 LT |
139 | goto out; |
140 | ||
b836c99f | 141 | inet_frag_kill(&fq->q, frags); |
1da177e4 | 142 | |
69df9d59 ED |
143 | rcu_read_lock(); |
144 | dev = dev_get_by_index_rcu(net, fq->iif); | |
a11d206d | 145 | if (!dev) |
69df9d59 | 146 | goto out_rcu_unlock; |
a11d206d | 147 | |
1d015503 | 148 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); |
1da177e4 | 149 | |
caaecdd3 | 150 | if (inet_frag_evicting(&fq->q)) |
2e404f63 NA |
151 | goto out_rcu_unlock; |
152 | ||
1d015503 | 153 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); |
2e404f63 | 154 | |
78c784c4 | 155 | /* Don't send error if the first segment did not arrive. */ |
06aa8b8a | 156 | if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments) |
69df9d59 | 157 | goto out_rcu_unlock; |
78c784c4 | 158 | |
2e404f63 NA |
159 | /* But use as source device on which LAST ARRIVED |
160 | * segment was received. And do not use fq->dev | |
161 | * pointer directly, device might already disappeared. | |
78c784c4 | 162 | */ |
5ab11c98 | 163 | fq->q.fragments->dev = dev; |
3ffe533c | 164 | icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); |
69df9d59 ED |
165 | out_rcu_unlock: |
166 | rcu_read_unlock(); | |
1da177e4 | 167 | out: |
5ab11c98 | 168 | spin_unlock(&fq->q.lock); |
b836c99f AW |
169 | inet_frag_put(&fq->q, frags); |
170 | } | |
171 | EXPORT_SYMBOL(ip6_expire_frag_queue); | |
172 | ||
173 | static void ip6_frag_expire(unsigned long data) | |
174 | { | |
175 | struct frag_queue *fq; | |
176 | struct net *net; | |
177 | ||
178 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); | |
179 | net = container_of(fq->q.net, struct net, ipv6.frags); | |
180 | ||
181 | ip6_expire_frag_queue(net, fq, &ip6_frags); | |
1da177e4 LT |
182 | } |
183 | ||
fc08c258 | 184 | static struct frag_queue * |
eec2e618 | 185 | fq_find(struct net *net, __be32 id, const struct in6_addr *src, |
264640fc | 186 | const struct in6_addr *dst, int iif, u8 ecn) |
1da177e4 | 187 | { |
c6fda282 PE |
188 | struct inet_frag_queue *q; |
189 | struct ip6_create_arg arg; | |
abd6523d | 190 | unsigned int hash; |
1da177e4 | 191 | |
c6fda282 | 192 | arg.id = id; |
0b5ccb2e | 193 | arg.user = IP6_DEFRAG_LOCAL_DELIVER; |
c6fda282 PE |
194 | arg.src = src; |
195 | arg.dst = dst; | |
264640fc | 196 | arg.iif = iif; |
eec2e618 | 197 | arg.ecn = ecn; |
9a375803 | 198 | |
b1190570 | 199 | hash = inet6_hash_frag(id, src, dst); |
1da177e4 | 200 | |
ac18e750 | 201 | q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); |
5a3da1fe HFS |
202 | if (IS_ERR_OR_NULL(q)) { |
203 | inet_frag_maybe_warn_overflow(q, pr_fmt()); | |
9546377c | 204 | return NULL; |
5a3da1fe | 205 | } |
c6fda282 | 206 | return container_of(q, struct frag_queue, q); |
1da177e4 LT |
207 | } |
208 | ||
f61944ef | 209 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, |
1da177e4 LT |
210 | struct frag_hdr *fhdr, int nhoff) |
211 | { | |
212 | struct sk_buff *prev, *next; | |
f61944ef | 213 | struct net_device *dev; |
1da177e4 | 214 | int offset, end; |
adf30907 | 215 | struct net *net = dev_net(skb_dst(skb)->dev); |
eec2e618 | 216 | u8 ecn; |
1da177e4 | 217 | |
06aa8b8a | 218 | if (fq->q.flags & INET_FRAG_COMPLETE) |
1da177e4 LT |
219 | goto err; |
220 | ||
221 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
222 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
223 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
1da177e4 LT |
224 | |
225 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
1d015503 ED |
226 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
227 | IPSTATS_MIB_INHDRERRORS); | |
d56f90a7 ACM |
228 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
229 | ((u8 *)&fhdr->frag_off - | |
230 | skb_network_header(skb))); | |
f61944ef | 231 | return -1; |
1da177e4 LT |
232 | } |
233 | ||
eec2e618 HFS |
234 | ecn = ip6_frag_ecn(ipv6_hdr(skb)); |
235 | ||
d56f90a7 ACM |
236 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
237 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 238 | skb->csum = csum_sub(skb->csum, |
d56f90a7 ACM |
239 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
240 | 0)); | |
241 | } | |
1da177e4 LT |
242 | |
243 | /* Is this the final fragment? */ | |
244 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
245 | /* If we already have some bits beyond end | |
246 | * or have different end, the segment is corrupted. | |
247 | */ | |
5ab11c98 | 248 | if (end < fq->q.len || |
06aa8b8a | 249 | ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) |
1da177e4 | 250 | goto err; |
06aa8b8a | 251 | fq->q.flags |= INET_FRAG_LAST_IN; |
5ab11c98 | 252 | fq->q.len = end; |
1da177e4 LT |
253 | } else { |
254 | /* Check if the fragment is rounded to 8 bytes. | |
255 | * Required by the RFC. | |
256 | */ | |
257 | if (end & 0x7) { | |
258 | /* RFC2460 says always send parameter problem in | |
259 | * this case. -DaveM | |
260 | */ | |
1d015503 ED |
261 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
262 | IPSTATS_MIB_INHDRERRORS); | |
1ab1457c | 263 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
1da177e4 | 264 | offsetof(struct ipv6hdr, payload_len)); |
f61944ef | 265 | return -1; |
1da177e4 | 266 | } |
5ab11c98 | 267 | if (end > fq->q.len) { |
1da177e4 | 268 | /* Some bits beyond end -> corruption. */ |
06aa8b8a | 269 | if (fq->q.flags & INET_FRAG_LAST_IN) |
1da177e4 | 270 | goto err; |
5ab11c98 | 271 | fq->q.len = end; |
1da177e4 LT |
272 | } |
273 | } | |
274 | ||
275 | if (end == offset) | |
276 | goto err; | |
277 | ||
278 | /* Point into the IP datagram 'data' part. */ | |
279 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
280 | goto err; | |
1ab1457c | 281 | |
42ca89c1 SH |
282 | if (pskb_trim_rcsum(skb, end - offset)) |
283 | goto err; | |
1da177e4 LT |
284 | |
285 | /* Find out which fragments are in front and at the back of us | |
286 | * in the chain of fragments so far. We must know where to put | |
287 | * this fragment, right? | |
288 | */ | |
d6bebca9 CG |
289 | prev = fq->q.fragments_tail; |
290 | if (!prev || FRAG6_CB(prev)->offset < offset) { | |
291 | next = NULL; | |
292 | goto found; | |
293 | } | |
1da177e4 | 294 | prev = NULL; |
67ba4152 | 295 | for (next = fq->q.fragments; next != NULL; next = next->next) { |
1da177e4 LT |
296 | if (FRAG6_CB(next)->offset >= offset) |
297 | break; /* bingo! */ | |
298 | prev = next; | |
299 | } | |
300 | ||
d6bebca9 | 301 | found: |
5de658f8 ED |
302 | /* RFC5722, Section 4, amended by Errata ID : 3089 |
303 | * When reassembling an IPv6 datagram, if | |
70789d70 ND |
304 | * one or more its constituent fragments is determined to be an |
305 | * overlapping fragment, the entire datagram (and any constituent | |
5de658f8 | 306 | * fragments) MUST be silently discarded. |
1da177e4 | 307 | */ |
1da177e4 | 308 | |
70789d70 ND |
309 | /* Check for overlap with preceding fragment. */ |
310 | if (prev && | |
f4642141 | 311 | (FRAG6_CB(prev)->offset + prev->len) > offset) |
70789d70 | 312 | goto discard_fq; |
1da177e4 | 313 | |
70789d70 ND |
314 | /* Look for overlap with succeeding segment. */ |
315 | if (next && FRAG6_CB(next)->offset < end) | |
316 | goto discard_fq; | |
1da177e4 LT |
317 | |
318 | FRAG6_CB(skb)->offset = offset; | |
319 | ||
320 | /* Insert this fragment in the chain of fragments. */ | |
321 | skb->next = next; | |
d6bebca9 CG |
322 | if (!next) |
323 | fq->q.fragments_tail = skb; | |
1da177e4 LT |
324 | if (prev) |
325 | prev->next = skb; | |
326 | else | |
5ab11c98 | 327 | fq->q.fragments = skb; |
1da177e4 | 328 | |
f61944ef HX |
329 | dev = skb->dev; |
330 | if (dev) { | |
331 | fq->iif = dev->ifindex; | |
332 | skb->dev = NULL; | |
333 | } | |
5ab11c98 PE |
334 | fq->q.stamp = skb->tstamp; |
335 | fq->q.meat += skb->len; | |
eec2e618 | 336 | fq->ecn |= ecn; |
0e60d245 | 337 | add_frag_mem_limit(fq->q.net, skb->truesize); |
1da177e4 LT |
338 | |
339 | /* The first fragment. | |
340 | * nhoffset is obtained from the first fragment, of course. | |
341 | */ | |
342 | if (offset == 0) { | |
343 | fq->nhoffset = nhoff; | |
06aa8b8a | 344 | fq->q.flags |= INET_FRAG_FIRST_IN; |
1da177e4 | 345 | } |
f61944ef | 346 | |
06aa8b8a | 347 | if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
97599dc7 ED |
348 | fq->q.meat == fq->q.len) { |
349 | int res; | |
350 | unsigned long orefdst = skb->_skb_refdst; | |
351 | ||
352 | skb->_skb_refdst = 0UL; | |
353 | res = ip6_frag_reasm(fq, prev, dev); | |
354 | skb->_skb_refdst = orefdst; | |
355 | return res; | |
356 | } | |
f61944ef | 357 | |
97599dc7 | 358 | skb_dst_drop(skb); |
f61944ef | 359 | return -1; |
1da177e4 | 360 | |
70789d70 | 361 | discard_fq: |
b836c99f | 362 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 363 | err: |
1d015503 ED |
364 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
365 | IPSTATS_MIB_REASMFAILS); | |
1da177e4 | 366 | kfree_skb(skb); |
f61944ef | 367 | return -1; |
1da177e4 LT |
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 | */ | |
f61944ef | 379 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
1da177e4 LT |
380 | struct net_device *dev) |
381 | { | |
2bad35b7 | 382 | struct net *net = container_of(fq->q.net, struct net, ipv6.frags); |
5ab11c98 | 383 | struct sk_buff *fp, *head = fq->q.fragments; |
1da177e4 LT |
384 | int payload_len; |
385 | unsigned int nhoff; | |
ec16439e | 386 | int sum_truesize; |
eec2e618 | 387 | u8 ecn; |
1da177e4 | 388 | |
b836c99f | 389 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 390 | |
eec2e618 HFS |
391 | ecn = ip_frag_ecn_table[fq->ecn]; |
392 | if (unlikely(ecn == 0xff)) | |
393 | goto out_fail; | |
394 | ||
f61944ef HX |
395 | /* Make the one we just received the head. */ |
396 | if (prev) { | |
397 | head = prev->next; | |
398 | fp = skb_clone(head, GFP_ATOMIC); | |
399 | ||
400 | if (!fp) | |
401 | goto out_oom; | |
402 | ||
403 | fp->next = head->next; | |
d6bebca9 CG |
404 | if (!fp->next) |
405 | fq->q.fragments_tail = fp; | |
f61944ef HX |
406 | prev->next = fp; |
407 | ||
5ab11c98 PE |
408 | skb_morph(head, fq->q.fragments); |
409 | head->next = fq->q.fragments->next; | |
f61944ef | 410 | |
808db80a | 411 | consume_skb(fq->q.fragments); |
5ab11c98 | 412 | fq->q.fragments = head; |
f61944ef HX |
413 | } |
414 | ||
547b792c IJ |
415 | WARN_ON(head == NULL); |
416 | WARN_ON(FRAG6_CB(head)->offset != 0); | |
1da177e4 LT |
417 | |
418 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 419 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 420 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 421 | sizeof(struct frag_hdr)); |
1da177e4 LT |
422 | if (payload_len > IPV6_MAXPLEN) |
423 | goto out_oversize; | |
424 | ||
425 | /* Head of list must not be cloned. */ | |
14bbd6a5 | 426 | if (skb_unclone(head, GFP_ATOMIC)) |
1da177e4 LT |
427 | goto out_oom; |
428 | ||
429 | /* If the first fragment is fragmented itself, we split | |
430 | * it to two chunks: the first with data and paged part | |
431 | * and the second, holding only fragments. */ | |
21dc3301 | 432 | if (skb_has_frag_list(head)) { |
1da177e4 LT |
433 | struct sk_buff *clone; |
434 | int i, plen = 0; | |
435 | ||
e5d08d71 | 436 | clone = alloc_skb(0, GFP_ATOMIC); |
63159f29 | 437 | if (!clone) |
1da177e4 LT |
438 | goto out_oom; |
439 | clone->next = head->next; | |
440 | head->next = clone; | |
441 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
4d9092bb | 442 | skb_frag_list_init(head); |
9e903e08 ED |
443 | for (i = 0; i < skb_shinfo(head)->nr_frags; i++) |
444 | plen += skb_frag_size(&skb_shinfo(head)->frags[i]); | |
1da177e4 LT |
445 | clone->len = clone->data_len = head->data_len - plen; |
446 | head->data_len -= clone->len; | |
447 | head->len -= clone->len; | |
448 | clone->csum = 0; | |
449 | clone->ip_summed = head->ip_summed; | |
0e60d245 | 450 | add_frag_mem_limit(fq->q.net, clone->truesize); |
1da177e4 LT |
451 | } |
452 | ||
453 | /* We have to remove fragment header from datagram and to relocate | |
454 | * header in order to calculate ICV correctly. */ | |
455 | nhoff = fq->nhoffset; | |
b0e380b1 | 456 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; |
1ab1457c | 457 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
1da177e4 | 458 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
459 | head->mac_header += sizeof(struct frag_hdr); |
460 | head->network_header += sizeof(struct frag_hdr); | |
1da177e4 | 461 | |
badff6d0 | 462 | skb_reset_transport_header(head); |
d56f90a7 | 463 | skb_push(head, head->data - skb_network_header(head)); |
1da177e4 | 464 | |
ec16439e ED |
465 | sum_truesize = head->truesize; |
466 | for (fp = head->next; fp;) { | |
467 | bool headstolen; | |
468 | int delta; | |
469 | struct sk_buff *next = fp->next; | |
470 | ||
471 | sum_truesize += fp->truesize; | |
1da177e4 LT |
472 | if (head->ip_summed != fp->ip_summed) |
473 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 474 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 | 475 | head->csum = csum_add(head->csum, fp->csum); |
ec16439e ED |
476 | |
477 | if (skb_try_coalesce(head, fp, &headstolen, &delta)) { | |
478 | kfree_skb_partial(fp, headstolen); | |
479 | } else { | |
480 | if (!skb_shinfo(head)->frag_list) | |
481 | skb_shinfo(head)->frag_list = fp; | |
482 | head->data_len += fp->len; | |
483 | head->len += fp->len; | |
484 | head->truesize += fp->truesize; | |
485 | } | |
486 | fp = next; | |
1da177e4 | 487 | } |
0e60d245 | 488 | sub_frag_mem_limit(fq->q.net, sum_truesize); |
1da177e4 LT |
489 | |
490 | head->next = NULL; | |
491 | head->dev = dev; | |
5ab11c98 | 492 | head->tstamp = fq->q.stamp; |
0660e03f | 493 | ipv6_hdr(head)->payload_len = htons(payload_len); |
eec2e618 | 494 | ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); |
951dbc8a | 495 | IP6CB(head)->nhoff = nhoff; |
f46078cf | 496 | IP6CB(head)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 | 497 | |
1da177e4 | 498 | /* Yes, and fold redundant checksum back. 8) */ |
6b83d28a DB |
499 | skb_postpush_rcsum(head, skb_network_header(head), |
500 | skb_network_header_len(head)); | |
1da177e4 | 501 | |
a11d206d | 502 | rcu_read_lock(); |
1d015503 | 503 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); |
a11d206d | 504 | rcu_read_unlock(); |
5ab11c98 | 505 | fq->q.fragments = NULL; |
d6bebca9 | 506 | fq->q.fragments_tail = NULL; |
1da177e4 LT |
507 | return 1; |
508 | ||
509 | out_oversize: | |
e87cc472 | 510 | net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); |
1da177e4 LT |
511 | goto out_fail; |
512 | out_oom: | |
e87cc472 | 513 | net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); |
1da177e4 | 514 | out_fail: |
a11d206d | 515 | rcu_read_lock(); |
1d015503 | 516 | __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); |
a11d206d | 517 | rcu_read_unlock(); |
1da177e4 LT |
518 | return -1; |
519 | } | |
520 | ||
e5bbef20 | 521 | static int ipv6_frag_rcv(struct sk_buff *skb) |
1da177e4 | 522 | { |
1da177e4 LT |
523 | struct frag_hdr *fhdr; |
524 | struct frag_queue *fq; | |
b71d1d42 | 525 | const struct ipv6hdr *hdr = ipv6_hdr(skb); |
adf30907 | 526 | struct net *net = dev_net(skb_dst(skb)->dev); |
1da177e4 | 527 | |
f46078cf HFS |
528 | if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) |
529 | goto fail_hdr; | |
530 | ||
1d015503 | 531 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); |
1da177e4 LT |
532 | |
533 | /* Jumbo payload inhibits frag. header */ | |
67ba4152 | 534 | if (hdr->payload_len == 0) |
98b3377c DL |
535 | goto fail_hdr; |
536 | ||
ea2ae17d | 537 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + |
98b3377c DL |
538 | sizeof(struct frag_hdr)))) |
539 | goto fail_hdr; | |
1da177e4 | 540 | |
0660e03f | 541 | hdr = ipv6_hdr(skb); |
9c70220b | 542 | fhdr = (struct frag_hdr *)skb_transport_header(skb); |
1da177e4 LT |
543 | |
544 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
545 | /* It is not a fragmented frame */ | |
b0e380b1 | 546 | skb->transport_header += sizeof(struct frag_hdr); |
1d015503 ED |
547 | __IP6_INC_STATS(net, |
548 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); | |
1da177e4 | 549 | |
d56f90a7 | 550 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); |
f46078cf | 551 | IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 LT |
552 | return 1; |
553 | } | |
554 | ||
eec2e618 | 555 | fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, |
264640fc | 556 | skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); |
53b24b8f | 557 | if (fq) { |
f61944ef | 558 | int ret; |
1da177e4 | 559 | |
5ab11c98 | 560 | spin_lock(&fq->q.lock); |
1da177e4 | 561 | |
f61944ef | 562 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); |
1da177e4 | 563 | |
5ab11c98 | 564 | spin_unlock(&fq->q.lock); |
b836c99f | 565 | inet_frag_put(&fq->q, &ip6_frags); |
1da177e4 LT |
566 | return ret; |
567 | } | |
568 | ||
1d015503 | 569 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
570 | kfree_skb(skb); |
571 | return -1; | |
98b3377c DL |
572 | |
573 | fail_hdr: | |
1d015503 ED |
574 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
575 | IPSTATS_MIB_INHDRERRORS); | |
98b3377c DL |
576 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); |
577 | return -1; | |
1da177e4 LT |
578 | } |
579 | ||
cc24beca | 580 | static const struct inet6_protocol frag_protocol = { |
1da177e4 LT |
581 | .handler = ipv6_frag_rcv, |
582 | .flags = INET6_PROTO_NOPOLICY, | |
583 | }; | |
584 | ||
8d8354d2 | 585 | #ifdef CONFIG_SYSCTL |
1bab4c75 NA |
586 | static int zero; |
587 | ||
0a64b4b8 | 588 | static struct ctl_table ip6_frags_ns_ctl_table[] = { |
8d8354d2 | 589 | { |
8d8354d2 | 590 | .procname = "ip6frag_high_thresh", |
e31e0bdc | 591 | .data = &init_net.ipv6.frags.high_thresh, |
8d8354d2 PE |
592 | .maxlen = sizeof(int), |
593 | .mode = 0644, | |
1bab4c75 NA |
594 | .proc_handler = proc_dointvec_minmax, |
595 | .extra1 = &init_net.ipv6.frags.low_thresh | |
8d8354d2 PE |
596 | }, |
597 | { | |
8d8354d2 | 598 | .procname = "ip6frag_low_thresh", |
e31e0bdc | 599 | .data = &init_net.ipv6.frags.low_thresh, |
8d8354d2 PE |
600 | .maxlen = sizeof(int), |
601 | .mode = 0644, | |
1bab4c75 NA |
602 | .proc_handler = proc_dointvec_minmax, |
603 | .extra1 = &zero, | |
604 | .extra2 = &init_net.ipv6.frags.high_thresh | |
8d8354d2 PE |
605 | }, |
606 | { | |
8d8354d2 | 607 | .procname = "ip6frag_time", |
b2fd5321 | 608 | .data = &init_net.ipv6.frags.timeout, |
8d8354d2 PE |
609 | .maxlen = sizeof(int), |
610 | .mode = 0644, | |
6d9f239a | 611 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 | 612 | }, |
7d291ebb PE |
613 | { } |
614 | }; | |
615 | ||
e3a57d18 FW |
616 | /* secret interval has been deprecated */ |
617 | static int ip6_frags_secret_interval_unused; | |
7d291ebb | 618 | static struct ctl_table ip6_frags_ctl_table[] = { |
8d8354d2 | 619 | { |
8d8354d2 | 620 | .procname = "ip6frag_secret_interval", |
e3a57d18 | 621 | .data = &ip6_frags_secret_interval_unused, |
8d8354d2 PE |
622 | .maxlen = sizeof(int), |
623 | .mode = 0644, | |
6d9f239a | 624 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
625 | }, |
626 | { } | |
627 | }; | |
628 | ||
2c8c1e72 | 629 | static int __net_init ip6_frags_ns_sysctl_register(struct net *net) |
8d8354d2 | 630 | { |
e4a2d5c2 | 631 | struct ctl_table *table; |
8d8354d2 PE |
632 | struct ctl_table_header *hdr; |
633 | ||
0a64b4b8 | 634 | table = ip6_frags_ns_ctl_table; |
09ad9bc7 | 635 | if (!net_eq(net, &init_net)) { |
0a64b4b8 | 636 | table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); |
63159f29 | 637 | if (!table) |
e4a2d5c2 PE |
638 | goto err_alloc; |
639 | ||
e31e0bdc | 640 | table[0].data = &net->ipv6.frags.high_thresh; |
1bab4c75 NA |
641 | table[0].extra1 = &net->ipv6.frags.low_thresh; |
642 | table[0].extra2 = &init_net.ipv6.frags.high_thresh; | |
e31e0bdc | 643 | table[1].data = &net->ipv6.frags.low_thresh; |
1bab4c75 | 644 | table[1].extra2 = &net->ipv6.frags.high_thresh; |
b2fd5321 | 645 | table[2].data = &net->ipv6.frags.timeout; |
464dc801 EB |
646 | |
647 | /* Don't export sysctls to unprivileged users */ | |
648 | if (net->user_ns != &init_user_ns) | |
649 | table[0].procname = NULL; | |
e4a2d5c2 PE |
650 | } |
651 | ||
ec8f23ce | 652 | hdr = register_net_sysctl(net, "net/ipv6", table); |
63159f29 | 653 | if (!hdr) |
e4a2d5c2 PE |
654 | goto err_reg; |
655 | ||
656 | net->ipv6.sysctl.frags_hdr = hdr; | |
657 | return 0; | |
658 | ||
659 | err_reg: | |
09ad9bc7 | 660 | if (!net_eq(net, &init_net)) |
e4a2d5c2 PE |
661 | kfree(table); |
662 | err_alloc: | |
663 | return -ENOMEM; | |
664 | } | |
665 | ||
2c8c1e72 | 666 | static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
667 | { |
668 | struct ctl_table *table; | |
669 | ||
670 | table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; | |
671 | unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); | |
3705e11a YH |
672 | if (!net_eq(net, &init_net)) |
673 | kfree(table); | |
8d8354d2 | 674 | } |
7d291ebb PE |
675 | |
676 | static struct ctl_table_header *ip6_ctl_header; | |
677 | ||
678 | static int ip6_frags_sysctl_register(void) | |
679 | { | |
43444757 | 680 | ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", |
7d291ebb PE |
681 | ip6_frags_ctl_table); |
682 | return ip6_ctl_header == NULL ? -ENOMEM : 0; | |
683 | } | |
684 | ||
685 | static void ip6_frags_sysctl_unregister(void) | |
686 | { | |
687 | unregister_net_sysctl_table(ip6_ctl_header); | |
688 | } | |
8d8354d2 | 689 | #else |
fc08c258 | 690 | static int ip6_frags_ns_sysctl_register(struct net *net) |
e71e0349 | 691 | { |
8d8354d2 PE |
692 | return 0; |
693 | } | |
e4a2d5c2 | 694 | |
fc08c258 | 695 | static void ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
696 | { |
697 | } | |
7d291ebb | 698 | |
fc08c258 | 699 | static int ip6_frags_sysctl_register(void) |
7d291ebb PE |
700 | { |
701 | return 0; | |
702 | } | |
703 | ||
fc08c258 | 704 | static void ip6_frags_sysctl_unregister(void) |
7d291ebb PE |
705 | { |
706 | } | |
8d8354d2 | 707 | #endif |
7d460db9 | 708 | |
2c8c1e72 | 709 | static int __net_init ipv6_frags_init_net(struct net *net) |
8d8354d2 | 710 | { |
1d6119ba ED |
711 | int res; |
712 | ||
7c070aa9 SW |
713 | net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
714 | net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
b2fd5321 | 715 | net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; |
8d8354d2 | 716 | |
1d6119ba ED |
717 | res = inet_frags_init_net(&net->ipv6.frags); |
718 | if (res) | |
719 | return res; | |
720 | res = ip6_frags_ns_sysctl_register(net); | |
721 | if (res) | |
722 | inet_frags_uninit_net(&net->ipv6.frags); | |
723 | return res; | |
e71e0349 DL |
724 | } |
725 | ||
2c8c1e72 | 726 | static void __net_exit ipv6_frags_exit_net(struct net *net) |
81566e83 | 727 | { |
0a64b4b8 | 728 | ip6_frags_ns_sysctl_unregister(net); |
81566e83 PE |
729 | inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); |
730 | } | |
731 | ||
732 | static struct pernet_operations ip6_frags_ops = { | |
733 | .init = ipv6_frags_init_net, | |
734 | .exit = ipv6_frags_exit_net, | |
735 | }; | |
736 | ||
853cbbaa | 737 | int __init ipv6_frag_init(void) |
1da177e4 | 738 | { |
853cbbaa | 739 | int ret; |
1da177e4 | 740 | |
853cbbaa DL |
741 | ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
742 | if (ret) | |
743 | goto out; | |
e71e0349 | 744 | |
7d291ebb PE |
745 | ret = ip6_frags_sysctl_register(); |
746 | if (ret) | |
747 | goto err_sysctl; | |
748 | ||
0002c630 PE |
749 | ret = register_pernet_subsys(&ip6_frags_ops); |
750 | if (ret) | |
751 | goto err_pernet; | |
8d8354d2 | 752 | |
321a3a99 | 753 | ip6_frags.hashfn = ip6_hashfn; |
c6fda282 | 754 | ip6_frags.constructor = ip6_frag_init; |
c9547709 | 755 | ip6_frags.destructor = NULL; |
1e4b8287 | 756 | ip6_frags.qsize = sizeof(struct frag_queue); |
abd6523d | 757 | ip6_frags.match = ip6_frag_match; |
e521db9d | 758 | ip6_frags.frag_expire = ip6_frag_expire; |
d4ad4d22 NA |
759 | ip6_frags.frags_cache_name = ip6_frag_cache_name; |
760 | ret = inet_frags_init(&ip6_frags); | |
761 | if (ret) | |
762 | goto err_pernet; | |
853cbbaa DL |
763 | out: |
764 | return ret; | |
0002c630 PE |
765 | |
766 | err_pernet: | |
7d291ebb PE |
767 | ip6_frags_sysctl_unregister(); |
768 | err_sysctl: | |
0002c630 PE |
769 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
770 | goto out; | |
853cbbaa DL |
771 | } |
772 | ||
773 | void ipv6_frag_exit(void) | |
774 | { | |
775 | inet_frags_fini(&ip6_frags); | |
7d291ebb | 776 | ip6_frags_sysctl_unregister(); |
81566e83 | 777 | unregister_pernet_subsys(&ip6_frags_ops); |
853cbbaa | 778 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
1da177e4 | 779 | } |