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 | |
1da177e4 LT |
63 | struct ip6frag_skb_cb |
64 | { | |
65 | struct inet6_skb_parm h; | |
66 | int offset; | |
67 | }; | |
68 | ||
69 | #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb)) | |
70 | ||
eec2e618 HFS |
71 | static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h) |
72 | { | |
73 | return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK); | |
74 | } | |
1da177e4 | 75 | |
7eb95156 | 76 | static struct inet_frags ip6_frags; |
1da177e4 | 77 | |
f61944ef HX |
78 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
79 | struct net_device *dev); | |
80 | ||
f6596f9d ZB |
81 | /* |
82 | * callers should be careful not to use the hash value outside the ipfrag_lock | |
83 | * as doing so could race with ipfrag_hash_rnd being recalculated. | |
84 | */ | |
93c8b90f IJ |
85 | unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, |
86 | const struct in6_addr *daddr, u32 rnd) | |
1da177e4 | 87 | { |
82a39eb6 JK |
88 | u32 c; |
89 | ||
8064b3cf ED |
90 | c = jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), |
91 | (__force u32)id, rnd); | |
1da177e4 | 92 | |
7eb95156 | 93 | return c & (INETFRAGS_HASHSZ - 1); |
1da177e4 | 94 | } |
93c8b90f | 95 | EXPORT_SYMBOL_GPL(inet6_hash_frag); |
1da177e4 | 96 | |
321a3a99 | 97 | static unsigned int ip6_hashfn(struct inet_frag_queue *q) |
1da177e4 | 98 | { |
321a3a99 | 99 | struct frag_queue *fq; |
1da177e4 | 100 | |
321a3a99 | 101 | fq = container_of(q, struct frag_queue, q); |
93c8b90f | 102 | return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd); |
1da177e4 LT |
103 | } |
104 | ||
cbc264ca | 105 | bool ip6_frag_match(struct inet_frag_queue *q, void *a) |
abd6523d PE |
106 | { |
107 | struct frag_queue *fq; | |
108 | struct ip6_create_arg *arg = a; | |
109 | ||
110 | fq = container_of(q, struct frag_queue, q); | |
cbc264ca ED |
111 | return fq->id == arg->id && |
112 | fq->user == arg->user && | |
113 | ipv6_addr_equal(&fq->saddr, arg->src) && | |
7cd9f602 MK |
114 | ipv6_addr_equal(&fq->daddr, arg->dst) && |
115 | (arg->iif == fq->iif || | |
116 | !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST | | |
117 | IPV6_ADDR_LINKLOCAL))); | |
abd6523d PE |
118 | } |
119 | EXPORT_SYMBOL(ip6_frag_match); | |
120 | ||
c6fda282 | 121 | void ip6_frag_init(struct inet_frag_queue *q, void *a) |
1da177e4 | 122 | { |
c6fda282 PE |
123 | struct frag_queue *fq = container_of(q, struct frag_queue, q); |
124 | struct ip6_create_arg *arg = a; | |
125 | ||
126 | fq->id = arg->id; | |
0b5ccb2e | 127 | fq->user = arg->user; |
4e3fd7a0 AD |
128 | fq->saddr = *arg->src; |
129 | fq->daddr = *arg->dst; | |
eec2e618 | 130 | fq->ecn = arg->ecn; |
1da177e4 | 131 | } |
c6fda282 | 132 | EXPORT_SYMBOL(ip6_frag_init); |
1da177e4 | 133 | |
b836c99f AW |
134 | void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, |
135 | struct inet_frags *frags) | |
1da177e4 | 136 | { |
a11d206d | 137 | struct net_device *dev = NULL; |
e521db9d | 138 | |
5ab11c98 | 139 | spin_lock(&fq->q.lock); |
1da177e4 | 140 | |
bc578a54 | 141 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
1da177e4 LT |
142 | goto out; |
143 | ||
b836c99f | 144 | inet_frag_kill(&fq->q, frags); |
1da177e4 | 145 | |
69df9d59 ED |
146 | rcu_read_lock(); |
147 | dev = dev_get_by_index_rcu(net, fq->iif); | |
a11d206d | 148 | if (!dev) |
69df9d59 | 149 | goto out_rcu_unlock; |
a11d206d | 150 | |
483a47d2 DL |
151 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); |
152 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
1da177e4 | 153 | |
78c784c4 | 154 | /* Don't send error if the first segment did not arrive. */ |
bc578a54 | 155 | if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) |
69df9d59 | 156 | goto out_rcu_unlock; |
78c784c4 | 157 | |
78c784c4 IO |
158 | /* |
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. | |
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 | ||
abd6523d | 184 | static __inline__ struct frag_queue * |
eec2e618 | 185 | fq_find(struct net *net, __be32 id, const struct in6_addr *src, |
7cd9f602 | 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; | |
7cd9f602 | 196 | arg.iif = iif; |
eec2e618 | 197 | arg.ecn = ecn; |
9a375803 PE |
198 | |
199 | read_lock(&ip6_frags.lock); | |
93c8b90f | 200 | hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd); |
1da177e4 | 201 | |
ac18e750 | 202 | q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); |
5a3da1fe HFS |
203 | if (IS_ERR_OR_NULL(q)) { |
204 | inet_frag_maybe_warn_overflow(q, pr_fmt()); | |
9546377c | 205 | return NULL; |
5a3da1fe | 206 | } |
c6fda282 | 207 | return container_of(q, struct frag_queue, q); |
1da177e4 LT |
208 | } |
209 | ||
f61944ef | 210 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, |
1da177e4 LT |
211 | struct frag_hdr *fhdr, int nhoff) |
212 | { | |
213 | struct sk_buff *prev, *next; | |
f61944ef | 214 | struct net_device *dev; |
1da177e4 | 215 | int offset, end; |
adf30907 | 216 | struct net *net = dev_net(skb_dst(skb)->dev); |
eec2e618 | 217 | u8 ecn; |
1da177e4 | 218 | |
bc578a54 | 219 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
1da177e4 LT |
220 | goto err; |
221 | ||
222 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
223 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
224 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
1da177e4 LT |
225 | |
226 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
adf30907 | 227 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), |
a11d206d | 228 | IPSTATS_MIB_INHDRERRORS); |
d56f90a7 ACM |
229 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
230 | ((u8 *)&fhdr->frag_off - | |
231 | skb_network_header(skb))); | |
f61944ef | 232 | return -1; |
1da177e4 LT |
233 | } |
234 | ||
eec2e618 HFS |
235 | ecn = ip6_frag_ecn(ipv6_hdr(skb)); |
236 | ||
d56f90a7 ACM |
237 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
238 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 239 | skb->csum = csum_sub(skb->csum, |
d56f90a7 ACM |
240 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
241 | 0)); | |
242 | } | |
1da177e4 LT |
243 | |
244 | /* Is this the final fragment? */ | |
245 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
246 | /* If we already have some bits beyond end | |
247 | * or have different end, the segment is corrupted. | |
248 | */ | |
5ab11c98 | 249 | if (end < fq->q.len || |
bc578a54 | 250 | ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) |
1da177e4 | 251 | goto err; |
bc578a54 | 252 | fq->q.last_in |= INET_FRAG_LAST_IN; |
5ab11c98 | 253 | fq->q.len = end; |
1da177e4 LT |
254 | } else { |
255 | /* Check if the fragment is rounded to 8 bytes. | |
256 | * Required by the RFC. | |
257 | */ | |
258 | if (end & 0x7) { | |
259 | /* RFC2460 says always send parameter problem in | |
260 | * this case. -DaveM | |
261 | */ | |
adf30907 | 262 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), |
a11d206d | 263 | IPSTATS_MIB_INHDRERRORS); |
1ab1457c | 264 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
1da177e4 | 265 | offsetof(struct ipv6hdr, payload_len)); |
f61944ef | 266 | return -1; |
1da177e4 | 267 | } |
5ab11c98 | 268 | if (end > fq->q.len) { |
1da177e4 | 269 | /* Some bits beyond end -> corruption. */ |
bc578a54 | 270 | if (fq->q.last_in & INET_FRAG_LAST_IN) |
1da177e4 | 271 | goto err; |
5ab11c98 | 272 | fq->q.len = end; |
1da177e4 LT |
273 | } |
274 | } | |
275 | ||
276 | if (end == offset) | |
277 | goto err; | |
278 | ||
279 | /* Point into the IP datagram 'data' part. */ | |
280 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
281 | goto err; | |
1ab1457c | 282 | |
42ca89c1 SH |
283 | if (pskb_trim_rcsum(skb, end - offset)) |
284 | goto err; | |
1da177e4 LT |
285 | |
286 | /* Find out which fragments are in front and at the back of us | |
287 | * in the chain of fragments so far. We must know where to put | |
288 | * this fragment, right? | |
289 | */ | |
d6bebca9 CG |
290 | prev = fq->q.fragments_tail; |
291 | if (!prev || FRAG6_CB(prev)->offset < offset) { | |
292 | next = NULL; | |
293 | goto found; | |
294 | } | |
1da177e4 | 295 | prev = NULL; |
5ab11c98 | 296 | for(next = fq->q.fragments; next != NULL; next = next->next) { |
1da177e4 LT |
297 | if (FRAG6_CB(next)->offset >= offset) |
298 | break; /* bingo! */ | |
299 | prev = next; | |
300 | } | |
301 | ||
d6bebca9 | 302 | found: |
5de658f8 ED |
303 | /* RFC5722, Section 4, amended by Errata ID : 3089 |
304 | * When reassembling an IPv6 datagram, if | |
70789d70 ND |
305 | * one or more its constituent fragments is determined to be an |
306 | * overlapping fragment, the entire datagram (and any constituent | |
5de658f8 | 307 | * fragments) MUST be silently discarded. |
1da177e4 | 308 | */ |
1da177e4 | 309 | |
70789d70 ND |
310 | /* Check for overlap with preceding fragment. */ |
311 | if (prev && | |
f4642141 | 312 | (FRAG6_CB(prev)->offset + prev->len) > offset) |
70789d70 | 313 | goto discard_fq; |
1da177e4 | 314 | |
70789d70 ND |
315 | /* Look for overlap with succeeding segment. */ |
316 | if (next && FRAG6_CB(next)->offset < end) | |
317 | goto discard_fq; | |
1da177e4 LT |
318 | |
319 | FRAG6_CB(skb)->offset = offset; | |
320 | ||
321 | /* Insert this fragment in the chain of fragments. */ | |
322 | skb->next = next; | |
d6bebca9 CG |
323 | if (!next) |
324 | fq->q.fragments_tail = skb; | |
1da177e4 LT |
325 | if (prev) |
326 | prev->next = skb; | |
327 | else | |
5ab11c98 | 328 | fq->q.fragments = skb; |
1da177e4 | 329 | |
f61944ef HX |
330 | dev = skb->dev; |
331 | if (dev) { | |
332 | fq->iif = dev->ifindex; | |
333 | skb->dev = NULL; | |
334 | } | |
5ab11c98 PE |
335 | fq->q.stamp = skb->tstamp; |
336 | fq->q.meat += skb->len; | |
eec2e618 | 337 | fq->ecn |= ecn; |
d433673e | 338 | add_frag_mem_limit(&fq->q, skb->truesize); |
1da177e4 LT |
339 | |
340 | /* The first fragment. | |
341 | * nhoffset is obtained from the first fragment, of course. | |
342 | */ | |
343 | if (offset == 0) { | |
344 | fq->nhoffset = nhoff; | |
bc578a54 | 345 | fq->q.last_in |= INET_FRAG_FIRST_IN; |
1da177e4 | 346 | } |
f61944ef | 347 | |
bc578a54 | 348 | if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
97599dc7 ED |
349 | fq->q.meat == fq->q.len) { |
350 | int res; | |
351 | unsigned long orefdst = skb->_skb_refdst; | |
352 | ||
353 | skb->_skb_refdst = 0UL; | |
354 | res = ip6_frag_reasm(fq, prev, dev); | |
355 | skb->_skb_refdst = orefdst; | |
356 | return res; | |
357 | } | |
f61944ef | 358 | |
97599dc7 | 359 | skb_dst_drop(skb); |
3ef0eb0d | 360 | inet_frag_lru_move(&fq->q); |
f61944ef | 361 | return -1; |
1da177e4 | 362 | |
70789d70 | 363 | discard_fq: |
b836c99f | 364 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 365 | err: |
adf30907 | 366 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
3bd653c8 | 367 | IPSTATS_MIB_REASMFAILS); |
1da177e4 | 368 | kfree_skb(skb); |
f61944ef | 369 | return -1; |
1da177e4 LT |
370 | } |
371 | ||
372 | /* | |
373 | * Check if this packet is complete. | |
374 | * Returns NULL on failure by any reason, and pointer | |
375 | * to current nexthdr field in reassembled frame. | |
376 | * | |
377 | * It is called with locked fq, and caller must check that | |
378 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
379 | * the last and the first frames arrived and all the bits are here. | |
380 | */ | |
f61944ef | 381 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
1da177e4 LT |
382 | struct net_device *dev) |
383 | { | |
2bad35b7 | 384 | struct net *net = container_of(fq->q.net, struct net, ipv6.frags); |
5ab11c98 | 385 | struct sk_buff *fp, *head = fq->q.fragments; |
1da177e4 LT |
386 | int payload_len; |
387 | unsigned int nhoff; | |
ec16439e | 388 | int sum_truesize; |
eec2e618 | 389 | u8 ecn; |
1da177e4 | 390 | |
b836c99f | 391 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 392 | |
eec2e618 HFS |
393 | ecn = ip_frag_ecn_table[fq->ecn]; |
394 | if (unlikely(ecn == 0xff)) | |
395 | goto out_fail; | |
396 | ||
f61944ef HX |
397 | /* Make the one we just received the head. */ |
398 | if (prev) { | |
399 | head = prev->next; | |
400 | fp = skb_clone(head, GFP_ATOMIC); | |
401 | ||
402 | if (!fp) | |
403 | goto out_oom; | |
404 | ||
405 | fp->next = head->next; | |
d6bebca9 CG |
406 | if (!fp->next) |
407 | fq->q.fragments_tail = fp; | |
f61944ef HX |
408 | prev->next = fp; |
409 | ||
5ab11c98 PE |
410 | skb_morph(head, fq->q.fragments); |
411 | head->next = fq->q.fragments->next; | |
f61944ef | 412 | |
808db80a | 413 | consume_skb(fq->q.fragments); |
5ab11c98 | 414 | fq->q.fragments = head; |
f61944ef HX |
415 | } |
416 | ||
547b792c IJ |
417 | WARN_ON(head == NULL); |
418 | WARN_ON(FRAG6_CB(head)->offset != 0); | |
1da177e4 LT |
419 | |
420 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 421 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 422 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 423 | sizeof(struct frag_hdr)); |
1da177e4 LT |
424 | if (payload_len > IPV6_MAXPLEN) |
425 | goto out_oversize; | |
426 | ||
427 | /* Head of list must not be cloned. */ | |
14bbd6a5 | 428 | if (skb_unclone(head, GFP_ATOMIC)) |
1da177e4 LT |
429 | goto out_oom; |
430 | ||
431 | /* If the first fragment is fragmented itself, we split | |
432 | * it to two chunks: the first with data and paged part | |
433 | * and the second, holding only fragments. */ | |
21dc3301 | 434 | if (skb_has_frag_list(head)) { |
1da177e4 LT |
435 | struct sk_buff *clone; |
436 | int i, plen = 0; | |
437 | ||
438 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) | |
439 | goto out_oom; | |
440 | clone->next = head->next; | |
441 | head->next = clone; | |
442 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
4d9092bb | 443 | skb_frag_list_init(head); |
9e903e08 ED |
444 | for (i = 0; i < skb_shinfo(head)->nr_frags; i++) |
445 | plen += skb_frag_size(&skb_shinfo(head)->frags[i]); | |
1da177e4 LT |
446 | clone->len = clone->data_len = head->data_len - plen; |
447 | head->data_len -= clone->len; | |
448 | head->len -= clone->len; | |
449 | clone->csum = 0; | |
450 | clone->ip_summed = head->ip_summed; | |
d433673e | 451 | add_frag_mem_limit(&fq->q, clone->truesize); |
1da177e4 LT |
452 | } |
453 | ||
454 | /* We have to remove fragment header from datagram and to relocate | |
455 | * header in order to calculate ICV correctly. */ | |
456 | nhoff = fq->nhoffset; | |
b0e380b1 | 457 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; |
1ab1457c | 458 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
1da177e4 | 459 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
460 | head->mac_header += sizeof(struct frag_hdr); |
461 | head->network_header += sizeof(struct frag_hdr); | |
1da177e4 | 462 | |
badff6d0 | 463 | skb_reset_transport_header(head); |
d56f90a7 | 464 | skb_push(head, head->data - skb_network_header(head)); |
1da177e4 | 465 | |
ec16439e ED |
466 | sum_truesize = head->truesize; |
467 | for (fp = head->next; fp;) { | |
468 | bool headstolen; | |
469 | int delta; | |
470 | struct sk_buff *next = fp->next; | |
471 | ||
472 | sum_truesize += fp->truesize; | |
1da177e4 LT |
473 | if (head->ip_summed != fp->ip_summed) |
474 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 475 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 | 476 | head->csum = csum_add(head->csum, fp->csum); |
ec16439e ED |
477 | |
478 | if (skb_try_coalesce(head, fp, &headstolen, &delta)) { | |
479 | kfree_skb_partial(fp, headstolen); | |
480 | } else { | |
481 | if (!skb_shinfo(head)->frag_list) | |
482 | skb_shinfo(head)->frag_list = fp; | |
483 | head->data_len += fp->len; | |
484 | head->len += fp->len; | |
485 | head->truesize += fp->truesize; | |
486 | } | |
487 | fp = next; | |
1da177e4 | 488 | } |
d433673e | 489 | sub_frag_mem_limit(&fq->q, sum_truesize); |
1da177e4 LT |
490 | |
491 | head->next = NULL; | |
492 | head->dev = dev; | |
5ab11c98 | 493 | head->tstamp = fq->q.stamp; |
0660e03f | 494 | ipv6_hdr(head)->payload_len = htons(payload_len); |
eec2e618 | 495 | ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); |
951dbc8a | 496 | IP6CB(head)->nhoff = nhoff; |
a829a288 | 497 | IP6CB(head)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 | 498 | |
1da177e4 | 499 | /* Yes, and fold redundant checksum back. 8) */ |
84fa7933 | 500 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 501 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 502 | skb_network_header_len(head), |
d56f90a7 | 503 | head->csum); |
1da177e4 | 504 | |
a11d206d | 505 | rcu_read_lock(); |
2bad35b7 | 506 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); |
a11d206d | 507 | rcu_read_unlock(); |
5ab11c98 | 508 | fq->q.fragments = NULL; |
d6bebca9 | 509 | fq->q.fragments_tail = NULL; |
1da177e4 LT |
510 | return 1; |
511 | ||
512 | out_oversize: | |
e87cc472 | 513 | net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); |
1da177e4 LT |
514 | goto out_fail; |
515 | out_oom: | |
e87cc472 | 516 | net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); |
1da177e4 | 517 | out_fail: |
a11d206d | 518 | rcu_read_lock(); |
2bad35b7 | 519 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); |
a11d206d | 520 | rcu_read_unlock(); |
1da177e4 LT |
521 | return -1; |
522 | } | |
523 | ||
e5bbef20 | 524 | static int ipv6_frag_rcv(struct sk_buff *skb) |
1da177e4 | 525 | { |
1da177e4 LT |
526 | struct frag_hdr *fhdr; |
527 | struct frag_queue *fq; | |
b71d1d42 | 528 | const struct ipv6hdr *hdr = ipv6_hdr(skb); |
adf30907 | 529 | struct net *net = dev_net(skb_dst(skb)->dev); |
6b102865 | 530 | int evicted; |
1da177e4 | 531 | |
a829a288 HFS |
532 | if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) |
533 | goto fail_hdr; | |
534 | ||
adf30907 | 535 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); |
1da177e4 LT |
536 | |
537 | /* Jumbo payload inhibits frag. header */ | |
98b3377c DL |
538 | if (hdr->payload_len==0) |
539 | goto fail_hdr; | |
540 | ||
ea2ae17d | 541 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + |
98b3377c DL |
542 | sizeof(struct frag_hdr)))) |
543 | goto fail_hdr; | |
1da177e4 | 544 | |
0660e03f | 545 | hdr = ipv6_hdr(skb); |
9c70220b | 546 | fhdr = (struct frag_hdr *)skb_transport_header(skb); |
1da177e4 LT |
547 | |
548 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
549 | /* It is not a fragmented frame */ | |
b0e380b1 | 550 | skb->transport_header += sizeof(struct frag_hdr); |
483a47d2 | 551 | IP6_INC_STATS_BH(net, |
adf30907 | 552 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); |
1da177e4 | 553 | |
d56f90a7 | 554 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); |
a829a288 | 555 | IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 LT |
556 | return 1; |
557 | } | |
558 | ||
5a0b77dc MK |
559 | if (!net->ipv6.frags.high_thresh) |
560 | goto fail_mem; | |
561 | ||
6b102865 AW |
562 | evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags, false); |
563 | if (evicted) | |
564 | IP6_ADD_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), | |
565 | IPSTATS_MIB_REASMFAILS, evicted); | |
1da177e4 | 566 | |
eec2e618 | 567 | fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, |
7cd9f602 | 568 | skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr)); |
9546377c | 569 | if (fq != NULL) { |
f61944ef | 570 | int ret; |
1da177e4 | 571 | |
5ab11c98 | 572 | spin_lock(&fq->q.lock); |
1da177e4 | 573 | |
f61944ef | 574 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); |
1da177e4 | 575 | |
5ab11c98 | 576 | spin_unlock(&fq->q.lock); |
b836c99f | 577 | inet_frag_put(&fq->q, &ip6_frags); |
1da177e4 LT |
578 | return ret; |
579 | } | |
580 | ||
5a0b77dc | 581 | fail_mem: |
adf30907 | 582 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
583 | kfree_skb(skb); |
584 | return -1; | |
98b3377c DL |
585 | |
586 | fail_hdr: | |
adf30907 | 587 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); |
98b3377c DL |
588 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); |
589 | return -1; | |
1da177e4 LT |
590 | } |
591 | ||
41135cc8 | 592 | static const struct inet6_protocol frag_protocol = |
1da177e4 LT |
593 | { |
594 | .handler = ipv6_frag_rcv, | |
595 | .flags = INET6_PROTO_NOPOLICY, | |
596 | }; | |
597 | ||
8d8354d2 | 598 | #ifdef CONFIG_SYSCTL |
0a64b4b8 | 599 | static struct ctl_table ip6_frags_ns_ctl_table[] = { |
8d8354d2 | 600 | { |
8d8354d2 | 601 | .procname = "ip6frag_high_thresh", |
e31e0bdc | 602 | .data = &init_net.ipv6.frags.high_thresh, |
8d8354d2 PE |
603 | .maxlen = sizeof(int), |
604 | .mode = 0644, | |
6d9f239a | 605 | .proc_handler = proc_dointvec |
8d8354d2 PE |
606 | }, |
607 | { | |
8d8354d2 | 608 | .procname = "ip6frag_low_thresh", |
e31e0bdc | 609 | .data = &init_net.ipv6.frags.low_thresh, |
8d8354d2 PE |
610 | .maxlen = sizeof(int), |
611 | .mode = 0644, | |
6d9f239a | 612 | .proc_handler = proc_dointvec |
8d8354d2 PE |
613 | }, |
614 | { | |
8d8354d2 | 615 | .procname = "ip6frag_time", |
b2fd5321 | 616 | .data = &init_net.ipv6.frags.timeout, |
8d8354d2 PE |
617 | .maxlen = sizeof(int), |
618 | .mode = 0644, | |
6d9f239a | 619 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 | 620 | }, |
7d291ebb PE |
621 | { } |
622 | }; | |
623 | ||
624 | static struct ctl_table ip6_frags_ctl_table[] = { | |
8d8354d2 | 625 | { |
8d8354d2 | 626 | .procname = "ip6frag_secret_interval", |
3b4bc4a2 | 627 | .data = &ip6_frags.secret_interval, |
8d8354d2 PE |
628 | .maxlen = sizeof(int), |
629 | .mode = 0644, | |
6d9f239a | 630 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
631 | }, |
632 | { } | |
633 | }; | |
634 | ||
2c8c1e72 | 635 | static int __net_init ip6_frags_ns_sysctl_register(struct net *net) |
8d8354d2 | 636 | { |
e4a2d5c2 | 637 | struct ctl_table *table; |
8d8354d2 PE |
638 | struct ctl_table_header *hdr; |
639 | ||
0a64b4b8 | 640 | table = ip6_frags_ns_ctl_table; |
09ad9bc7 | 641 | if (!net_eq(net, &init_net)) { |
0a64b4b8 | 642 | table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); |
e4a2d5c2 PE |
643 | if (table == NULL) |
644 | goto err_alloc; | |
645 | ||
e31e0bdc PE |
646 | table[0].data = &net->ipv6.frags.high_thresh; |
647 | table[1].data = &net->ipv6.frags.low_thresh; | |
b2fd5321 | 648 | table[2].data = &net->ipv6.frags.timeout; |
464dc801 EB |
649 | |
650 | /* Don't export sysctls to unprivileged users */ | |
651 | if (net->user_ns != &init_user_ns) | |
652 | table[0].procname = NULL; | |
e4a2d5c2 PE |
653 | } |
654 | ||
ec8f23ce | 655 | hdr = register_net_sysctl(net, "net/ipv6", table); |
e4a2d5c2 PE |
656 | if (hdr == NULL) |
657 | goto err_reg; | |
658 | ||
659 | net->ipv6.sysctl.frags_hdr = hdr; | |
660 | return 0; | |
661 | ||
662 | err_reg: | |
09ad9bc7 | 663 | if (!net_eq(net, &init_net)) |
e4a2d5c2 PE |
664 | kfree(table); |
665 | err_alloc: | |
666 | return -ENOMEM; | |
667 | } | |
668 | ||
2c8c1e72 | 669 | static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
670 | { |
671 | struct ctl_table *table; | |
672 | ||
673 | table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; | |
674 | unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); | |
3705e11a YH |
675 | if (!net_eq(net, &init_net)) |
676 | kfree(table); | |
8d8354d2 | 677 | } |
7d291ebb PE |
678 | |
679 | static struct ctl_table_header *ip6_ctl_header; | |
680 | ||
681 | static int ip6_frags_sysctl_register(void) | |
682 | { | |
43444757 | 683 | ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", |
7d291ebb PE |
684 | ip6_frags_ctl_table); |
685 | return ip6_ctl_header == NULL ? -ENOMEM : 0; | |
686 | } | |
687 | ||
688 | static void ip6_frags_sysctl_unregister(void) | |
689 | { | |
690 | unregister_net_sysctl_table(ip6_ctl_header); | |
691 | } | |
8d8354d2 | 692 | #else |
0a64b4b8 | 693 | static inline int ip6_frags_ns_sysctl_register(struct net *net) |
e71e0349 | 694 | { |
8d8354d2 PE |
695 | return 0; |
696 | } | |
e4a2d5c2 | 697 | |
0a64b4b8 | 698 | static inline void ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
699 | { |
700 | } | |
7d291ebb PE |
701 | |
702 | static inline int ip6_frags_sysctl_register(void) | |
703 | { | |
704 | return 0; | |
705 | } | |
706 | ||
707 | static inline void ip6_frags_sysctl_unregister(void) | |
708 | { | |
709 | } | |
8d8354d2 | 710 | #endif |
7d460db9 | 711 | |
2c8c1e72 | 712 | static int __net_init ipv6_frags_init_net(struct net *net) |
8d8354d2 | 713 | { |
7c070aa9 SW |
714 | net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
715 | net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
b2fd5321 | 716 | net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; |
8d8354d2 | 717 | |
e5a2bb84 PE |
718 | inet_frags_init_net(&net->ipv6.frags); |
719 | ||
0a64b4b8 | 720 | return ip6_frags_ns_sysctl_register(net); |
e71e0349 DL |
721 | } |
722 | ||
2c8c1e72 | 723 | static void __net_exit ipv6_frags_exit_net(struct net *net) |
81566e83 | 724 | { |
0a64b4b8 | 725 | ip6_frags_ns_sysctl_unregister(net); |
81566e83 PE |
726 | inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); |
727 | } | |
728 | ||
729 | static struct pernet_operations ip6_frags_ops = { | |
730 | .init = ipv6_frags_init_net, | |
731 | .exit = ipv6_frags_exit_net, | |
732 | }; | |
733 | ||
853cbbaa | 734 | int __init ipv6_frag_init(void) |
1da177e4 | 735 | { |
853cbbaa | 736 | int ret; |
1da177e4 | 737 | |
853cbbaa DL |
738 | ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
739 | if (ret) | |
740 | goto out; | |
e71e0349 | 741 | |
7d291ebb PE |
742 | ret = ip6_frags_sysctl_register(); |
743 | if (ret) | |
744 | goto err_sysctl; | |
745 | ||
0002c630 PE |
746 | ret = register_pernet_subsys(&ip6_frags_ops); |
747 | if (ret) | |
748 | goto err_pernet; | |
8d8354d2 | 749 | |
321a3a99 | 750 | ip6_frags.hashfn = ip6_hashfn; |
c6fda282 | 751 | ip6_frags.constructor = ip6_frag_init; |
c9547709 | 752 | ip6_frags.destructor = NULL; |
1e4b8287 PE |
753 | ip6_frags.skb_free = NULL; |
754 | ip6_frags.qsize = sizeof(struct frag_queue); | |
abd6523d | 755 | ip6_frags.match = ip6_frag_match; |
e521db9d | 756 | ip6_frags.frag_expire = ip6_frag_expire; |
3b4bc4a2 | 757 | ip6_frags.secret_interval = 10 * 60 * HZ; |
7eb95156 | 758 | inet_frags_init(&ip6_frags); |
853cbbaa DL |
759 | out: |
760 | return ret; | |
0002c630 PE |
761 | |
762 | err_pernet: | |
7d291ebb PE |
763 | ip6_frags_sysctl_unregister(); |
764 | err_sysctl: | |
0002c630 PE |
765 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
766 | goto out; | |
853cbbaa DL |
767 | } |
768 | ||
769 | void ipv6_frag_exit(void) | |
770 | { | |
771 | inet_frags_fini(&ip6_frags); | |
7d291ebb | 772 | ip6_frags_sysctl_unregister(); |
81566e83 | 773 | unregister_pernet_subsys(&ip6_frags_ops); |
853cbbaa | 774 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
1da177e4 | 775 | } |