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Commit | Line | Data |
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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 | */ | |
b1190570 HFS |
85 | static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr, |
86 | const struct in6_addr *daddr) | |
1da177e4 | 87 | { |
b1190570 | 88 | net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd)); |
fb3cfe6e FW |
89 | return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr), |
90 | (__force u32)id, ip6_frags.rnd); | |
1da177e4 LT |
91 | } |
92 | ||
36c77782 | 93 | static unsigned int ip6_hashfn(const struct inet_frag_queue *q) |
1da177e4 | 94 | { |
36c77782 | 95 | const struct frag_queue *fq; |
1da177e4 | 96 | |
321a3a99 | 97 | fq = container_of(q, struct frag_queue, q); |
b1190570 | 98 | return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr); |
1da177e4 LT |
99 | } |
100 | ||
36c77782 | 101 | bool ip6_frag_match(const struct inet_frag_queue *q, const void *a) |
abd6523d | 102 | { |
36c77782 FW |
103 | const struct frag_queue *fq; |
104 | const struct ip6_create_arg *arg = a; | |
abd6523d PE |
105 | |
106 | fq = container_of(q, struct frag_queue, q); | |
cbc264ca ED |
107 | return fq->id == arg->id && |
108 | fq->user == arg->user && | |
109 | ipv6_addr_equal(&fq->saddr, arg->src) && | |
110 | ipv6_addr_equal(&fq->daddr, arg->dst); | |
abd6523d PE |
111 | } |
112 | EXPORT_SYMBOL(ip6_frag_match); | |
113 | ||
36c77782 | 114 | void ip6_frag_init(struct inet_frag_queue *q, const void *a) |
1da177e4 | 115 | { |
c6fda282 | 116 | struct frag_queue *fq = container_of(q, struct frag_queue, q); |
36c77782 | 117 | const struct ip6_create_arg *arg = a; |
c6fda282 PE |
118 | |
119 | fq->id = arg->id; | |
0b5ccb2e | 120 | fq->user = arg->user; |
4e3fd7a0 AD |
121 | fq->saddr = *arg->src; |
122 | fq->daddr = *arg->dst; | |
eec2e618 | 123 | fq->ecn = arg->ecn; |
1da177e4 | 124 | } |
c6fda282 | 125 | EXPORT_SYMBOL(ip6_frag_init); |
1da177e4 | 126 | |
b836c99f AW |
127 | void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq, |
128 | struct inet_frags *frags) | |
1da177e4 | 129 | { |
a11d206d | 130 | struct net_device *dev = NULL; |
e521db9d | 131 | |
5ab11c98 | 132 | spin_lock(&fq->q.lock); |
1da177e4 | 133 | |
bc578a54 | 134 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
1da177e4 LT |
135 | goto out; |
136 | ||
b836c99f | 137 | inet_frag_kill(&fq->q, frags); |
1da177e4 | 138 | |
69df9d59 ED |
139 | rcu_read_lock(); |
140 | dev = dev_get_by_index_rcu(net, fq->iif); | |
a11d206d | 141 | if (!dev) |
69df9d59 | 142 | goto out_rcu_unlock; |
a11d206d | 143 | |
483a47d2 DL |
144 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT); |
145 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); | |
1da177e4 | 146 | |
78c784c4 | 147 | /* Don't send error if the first segment did not arrive. */ |
bc578a54 | 148 | if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) |
69df9d59 | 149 | goto out_rcu_unlock; |
78c784c4 | 150 | |
78c784c4 IO |
151 | /* |
152 | But use as source device on which LAST ARRIVED | |
153 | segment was received. And do not use fq->dev | |
154 | pointer directly, device might already disappeared. | |
155 | */ | |
5ab11c98 | 156 | fq->q.fragments->dev = dev; |
3ffe533c | 157 | icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0); |
69df9d59 ED |
158 | out_rcu_unlock: |
159 | rcu_read_unlock(); | |
1da177e4 | 160 | out: |
5ab11c98 | 161 | spin_unlock(&fq->q.lock); |
b836c99f AW |
162 | inet_frag_put(&fq->q, frags); |
163 | } | |
164 | EXPORT_SYMBOL(ip6_expire_frag_queue); | |
165 | ||
166 | static void ip6_frag_expire(unsigned long data) | |
167 | { | |
168 | struct frag_queue *fq; | |
169 | struct net *net; | |
170 | ||
171 | fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); | |
172 | net = container_of(fq->q.net, struct net, ipv6.frags); | |
173 | ||
174 | ip6_expire_frag_queue(net, fq, &ip6_frags); | |
1da177e4 LT |
175 | } |
176 | ||
abd6523d | 177 | static __inline__ struct frag_queue * |
eec2e618 HFS |
178 | fq_find(struct net *net, __be32 id, const struct in6_addr *src, |
179 | const struct in6_addr *dst, u8 ecn) | |
1da177e4 | 180 | { |
c6fda282 PE |
181 | struct inet_frag_queue *q; |
182 | struct ip6_create_arg arg; | |
abd6523d | 183 | unsigned int hash; |
1da177e4 | 184 | |
c6fda282 | 185 | arg.id = id; |
0b5ccb2e | 186 | arg.user = IP6_DEFRAG_LOCAL_DELIVER; |
c6fda282 PE |
187 | arg.src = src; |
188 | arg.dst = dst; | |
eec2e618 | 189 | arg.ecn = ecn; |
9a375803 PE |
190 | |
191 | read_lock(&ip6_frags.lock); | |
b1190570 | 192 | hash = inet6_hash_frag(id, src, dst); |
1da177e4 | 193 | |
ac18e750 | 194 | q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash); |
5a3da1fe HFS |
195 | if (IS_ERR_OR_NULL(q)) { |
196 | inet_frag_maybe_warn_overflow(q, pr_fmt()); | |
9546377c | 197 | return NULL; |
5a3da1fe | 198 | } |
c6fda282 | 199 | return container_of(q, struct frag_queue, q); |
1da177e4 LT |
200 | } |
201 | ||
f61944ef | 202 | static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, |
1da177e4 LT |
203 | struct frag_hdr *fhdr, int nhoff) |
204 | { | |
205 | struct sk_buff *prev, *next; | |
f61944ef | 206 | struct net_device *dev; |
1da177e4 | 207 | int offset, end; |
adf30907 | 208 | struct net *net = dev_net(skb_dst(skb)->dev); |
eec2e618 | 209 | u8 ecn; |
1da177e4 | 210 | |
bc578a54 | 211 | if (fq->q.last_in & INET_FRAG_COMPLETE) |
1da177e4 LT |
212 | goto err; |
213 | ||
214 | offset = ntohs(fhdr->frag_off) & ~0x7; | |
0660e03f ACM |
215 | end = offset + (ntohs(ipv6_hdr(skb)->payload_len) - |
216 | ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1))); | |
1da177e4 LT |
217 | |
218 | if ((unsigned int)end > IPV6_MAXPLEN) { | |
adf30907 | 219 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), |
a11d206d | 220 | IPSTATS_MIB_INHDRERRORS); |
d56f90a7 ACM |
221 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
222 | ((u8 *)&fhdr->frag_off - | |
223 | skb_network_header(skb))); | |
f61944ef | 224 | return -1; |
1da177e4 LT |
225 | } |
226 | ||
eec2e618 HFS |
227 | ecn = ip6_frag_ecn(ipv6_hdr(skb)); |
228 | ||
d56f90a7 ACM |
229 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
230 | const unsigned char *nh = skb_network_header(skb); | |
1ab1457c | 231 | skb->csum = csum_sub(skb->csum, |
d56f90a7 ACM |
232 | csum_partial(nh, (u8 *)(fhdr + 1) - nh, |
233 | 0)); | |
234 | } | |
1da177e4 LT |
235 | |
236 | /* Is this the final fragment? */ | |
237 | if (!(fhdr->frag_off & htons(IP6_MF))) { | |
238 | /* If we already have some bits beyond end | |
239 | * or have different end, the segment is corrupted. | |
240 | */ | |
5ab11c98 | 241 | if (end < fq->q.len || |
bc578a54 | 242 | ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) |
1da177e4 | 243 | goto err; |
bc578a54 | 244 | fq->q.last_in |= INET_FRAG_LAST_IN; |
5ab11c98 | 245 | fq->q.len = end; |
1da177e4 LT |
246 | } else { |
247 | /* Check if the fragment is rounded to 8 bytes. | |
248 | * Required by the RFC. | |
249 | */ | |
250 | if (end & 0x7) { | |
251 | /* RFC2460 says always send parameter problem in | |
252 | * this case. -DaveM | |
253 | */ | |
adf30907 | 254 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), |
a11d206d | 255 | IPSTATS_MIB_INHDRERRORS); |
1ab1457c | 256 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
1da177e4 | 257 | offsetof(struct ipv6hdr, payload_len)); |
f61944ef | 258 | return -1; |
1da177e4 | 259 | } |
5ab11c98 | 260 | if (end > fq->q.len) { |
1da177e4 | 261 | /* Some bits beyond end -> corruption. */ |
bc578a54 | 262 | if (fq->q.last_in & INET_FRAG_LAST_IN) |
1da177e4 | 263 | goto err; |
5ab11c98 | 264 | fq->q.len = end; |
1da177e4 LT |
265 | } |
266 | } | |
267 | ||
268 | if (end == offset) | |
269 | goto err; | |
270 | ||
271 | /* Point into the IP datagram 'data' part. */ | |
272 | if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) | |
273 | goto err; | |
1ab1457c | 274 | |
42ca89c1 SH |
275 | if (pskb_trim_rcsum(skb, end - offset)) |
276 | goto err; | |
1da177e4 LT |
277 | |
278 | /* Find out which fragments are in front and at the back of us | |
279 | * in the chain of fragments so far. We must know where to put | |
280 | * this fragment, right? | |
281 | */ | |
d6bebca9 CG |
282 | prev = fq->q.fragments_tail; |
283 | if (!prev || FRAG6_CB(prev)->offset < offset) { | |
284 | next = NULL; | |
285 | goto found; | |
286 | } | |
1da177e4 | 287 | prev = NULL; |
5ab11c98 | 288 | for(next = fq->q.fragments; next != NULL; next = next->next) { |
1da177e4 LT |
289 | if (FRAG6_CB(next)->offset >= offset) |
290 | break; /* bingo! */ | |
291 | prev = next; | |
292 | } | |
293 | ||
d6bebca9 | 294 | found: |
5de658f8 ED |
295 | /* RFC5722, Section 4, amended by Errata ID : 3089 |
296 | * When reassembling an IPv6 datagram, if | |
70789d70 ND |
297 | * one or more its constituent fragments is determined to be an |
298 | * overlapping fragment, the entire datagram (and any constituent | |
5de658f8 | 299 | * fragments) MUST be silently discarded. |
1da177e4 | 300 | */ |
1da177e4 | 301 | |
70789d70 ND |
302 | /* Check for overlap with preceding fragment. */ |
303 | if (prev && | |
f4642141 | 304 | (FRAG6_CB(prev)->offset + prev->len) > offset) |
70789d70 | 305 | goto discard_fq; |
1da177e4 | 306 | |
70789d70 ND |
307 | /* Look for overlap with succeeding segment. */ |
308 | if (next && FRAG6_CB(next)->offset < end) | |
309 | goto discard_fq; | |
1da177e4 LT |
310 | |
311 | FRAG6_CB(skb)->offset = offset; | |
312 | ||
313 | /* Insert this fragment in the chain of fragments. */ | |
314 | skb->next = next; | |
d6bebca9 CG |
315 | if (!next) |
316 | fq->q.fragments_tail = skb; | |
1da177e4 LT |
317 | if (prev) |
318 | prev->next = skb; | |
319 | else | |
5ab11c98 | 320 | fq->q.fragments = skb; |
1da177e4 | 321 | |
f61944ef HX |
322 | dev = skb->dev; |
323 | if (dev) { | |
324 | fq->iif = dev->ifindex; | |
325 | skb->dev = NULL; | |
326 | } | |
5ab11c98 PE |
327 | fq->q.stamp = skb->tstamp; |
328 | fq->q.meat += skb->len; | |
eec2e618 | 329 | fq->ecn |= ecn; |
d433673e | 330 | add_frag_mem_limit(&fq->q, skb->truesize); |
1da177e4 LT |
331 | |
332 | /* The first fragment. | |
333 | * nhoffset is obtained from the first fragment, of course. | |
334 | */ | |
335 | if (offset == 0) { | |
336 | fq->nhoffset = nhoff; | |
bc578a54 | 337 | fq->q.last_in |= INET_FRAG_FIRST_IN; |
1da177e4 | 338 | } |
f61944ef | 339 | |
bc578a54 | 340 | if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && |
97599dc7 ED |
341 | fq->q.meat == fq->q.len) { |
342 | int res; | |
343 | unsigned long orefdst = skb->_skb_refdst; | |
344 | ||
345 | skb->_skb_refdst = 0UL; | |
346 | res = ip6_frag_reasm(fq, prev, dev); | |
347 | skb->_skb_refdst = orefdst; | |
348 | return res; | |
349 | } | |
f61944ef | 350 | |
97599dc7 | 351 | skb_dst_drop(skb); |
3ef0eb0d | 352 | inet_frag_lru_move(&fq->q); |
f61944ef | 353 | return -1; |
1da177e4 | 354 | |
70789d70 | 355 | discard_fq: |
b836c99f | 356 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 357 | err: |
adf30907 | 358 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
3bd653c8 | 359 | IPSTATS_MIB_REASMFAILS); |
1da177e4 | 360 | kfree_skb(skb); |
f61944ef | 361 | return -1; |
1da177e4 LT |
362 | } |
363 | ||
364 | /* | |
365 | * Check if this packet is complete. | |
366 | * Returns NULL on failure by any reason, and pointer | |
367 | * to current nexthdr field in reassembled frame. | |
368 | * | |
369 | * It is called with locked fq, and caller must check that | |
370 | * queue is eligible for reassembly i.e. it is not COMPLETE, | |
371 | * the last and the first frames arrived and all the bits are here. | |
372 | */ | |
f61944ef | 373 | static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, |
1da177e4 LT |
374 | struct net_device *dev) |
375 | { | |
2bad35b7 | 376 | struct net *net = container_of(fq->q.net, struct net, ipv6.frags); |
5ab11c98 | 377 | struct sk_buff *fp, *head = fq->q.fragments; |
1da177e4 LT |
378 | int payload_len; |
379 | unsigned int nhoff; | |
ec16439e | 380 | int sum_truesize; |
eec2e618 | 381 | u8 ecn; |
1da177e4 | 382 | |
b836c99f | 383 | inet_frag_kill(&fq->q, &ip6_frags); |
1da177e4 | 384 | |
eec2e618 HFS |
385 | ecn = ip_frag_ecn_table[fq->ecn]; |
386 | if (unlikely(ecn == 0xff)) | |
387 | goto out_fail; | |
388 | ||
f61944ef HX |
389 | /* Make the one we just received the head. */ |
390 | if (prev) { | |
391 | head = prev->next; | |
392 | fp = skb_clone(head, GFP_ATOMIC); | |
393 | ||
394 | if (!fp) | |
395 | goto out_oom; | |
396 | ||
397 | fp->next = head->next; | |
d6bebca9 CG |
398 | if (!fp->next) |
399 | fq->q.fragments_tail = fp; | |
f61944ef HX |
400 | prev->next = fp; |
401 | ||
5ab11c98 PE |
402 | skb_morph(head, fq->q.fragments); |
403 | head->next = fq->q.fragments->next; | |
f61944ef | 404 | |
808db80a | 405 | consume_skb(fq->q.fragments); |
5ab11c98 | 406 | fq->q.fragments = head; |
f61944ef HX |
407 | } |
408 | ||
547b792c IJ |
409 | WARN_ON(head == NULL); |
410 | WARN_ON(FRAG6_CB(head)->offset != 0); | |
1da177e4 LT |
411 | |
412 | /* Unfragmented part is taken from the first segment. */ | |
d56f90a7 | 413 | payload_len = ((head->data - skb_network_header(head)) - |
5ab11c98 | 414 | sizeof(struct ipv6hdr) + fq->q.len - |
d56f90a7 | 415 | sizeof(struct frag_hdr)); |
1da177e4 LT |
416 | if (payload_len > IPV6_MAXPLEN) |
417 | goto out_oversize; | |
418 | ||
419 | /* Head of list must not be cloned. */ | |
14bbd6a5 | 420 | if (skb_unclone(head, GFP_ATOMIC)) |
1da177e4 LT |
421 | goto out_oom; |
422 | ||
423 | /* If the first fragment is fragmented itself, we split | |
424 | * it to two chunks: the first with data and paged part | |
425 | * and the second, holding only fragments. */ | |
21dc3301 | 426 | if (skb_has_frag_list(head)) { |
1da177e4 LT |
427 | struct sk_buff *clone; |
428 | int i, plen = 0; | |
429 | ||
430 | if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) | |
431 | goto out_oom; | |
432 | clone->next = head->next; | |
433 | head->next = clone; | |
434 | skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; | |
4d9092bb | 435 | skb_frag_list_init(head); |
9e903e08 ED |
436 | for (i = 0; i < skb_shinfo(head)->nr_frags; i++) |
437 | plen += skb_frag_size(&skb_shinfo(head)->frags[i]); | |
1da177e4 LT |
438 | clone->len = clone->data_len = head->data_len - plen; |
439 | head->data_len -= clone->len; | |
440 | head->len -= clone->len; | |
441 | clone->csum = 0; | |
442 | clone->ip_summed = head->ip_summed; | |
d433673e | 443 | add_frag_mem_limit(&fq->q, clone->truesize); |
1da177e4 LT |
444 | } |
445 | ||
446 | /* We have to remove fragment header from datagram and to relocate | |
447 | * header in order to calculate ICV correctly. */ | |
448 | nhoff = fq->nhoffset; | |
b0e380b1 | 449 | skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; |
1ab1457c | 450 | memmove(head->head + sizeof(struct frag_hdr), head->head, |
1da177e4 | 451 | (head->data - head->head) - sizeof(struct frag_hdr)); |
b0e380b1 ACM |
452 | head->mac_header += sizeof(struct frag_hdr); |
453 | head->network_header += sizeof(struct frag_hdr); | |
1da177e4 | 454 | |
badff6d0 | 455 | skb_reset_transport_header(head); |
d56f90a7 | 456 | skb_push(head, head->data - skb_network_header(head)); |
1da177e4 | 457 | |
ec16439e ED |
458 | sum_truesize = head->truesize; |
459 | for (fp = head->next; fp;) { | |
460 | bool headstolen; | |
461 | int delta; | |
462 | struct sk_buff *next = fp->next; | |
463 | ||
464 | sum_truesize += fp->truesize; | |
1da177e4 LT |
465 | if (head->ip_summed != fp->ip_summed) |
466 | head->ip_summed = CHECKSUM_NONE; | |
84fa7933 | 467 | else if (head->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 | 468 | head->csum = csum_add(head->csum, fp->csum); |
ec16439e ED |
469 | |
470 | if (skb_try_coalesce(head, fp, &headstolen, &delta)) { | |
471 | kfree_skb_partial(fp, headstolen); | |
472 | } else { | |
473 | if (!skb_shinfo(head)->frag_list) | |
474 | skb_shinfo(head)->frag_list = fp; | |
475 | head->data_len += fp->len; | |
476 | head->len += fp->len; | |
477 | head->truesize += fp->truesize; | |
478 | } | |
479 | fp = next; | |
1da177e4 | 480 | } |
d433673e | 481 | sub_frag_mem_limit(&fq->q, sum_truesize); |
1da177e4 LT |
482 | |
483 | head->next = NULL; | |
484 | head->dev = dev; | |
5ab11c98 | 485 | head->tstamp = fq->q.stamp; |
0660e03f | 486 | ipv6_hdr(head)->payload_len = htons(payload_len); |
eec2e618 | 487 | ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); |
951dbc8a | 488 | IP6CB(head)->nhoff = nhoff; |
f46078cf | 489 | IP6CB(head)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 | 490 | |
1da177e4 | 491 | /* Yes, and fold redundant checksum back. 8) */ |
84fa7933 | 492 | if (head->ip_summed == CHECKSUM_COMPLETE) |
d56f90a7 | 493 | head->csum = csum_partial(skb_network_header(head), |
cfe1fc77 | 494 | skb_network_header_len(head), |
d56f90a7 | 495 | head->csum); |
1da177e4 | 496 | |
a11d206d | 497 | rcu_read_lock(); |
2bad35b7 | 498 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); |
a11d206d | 499 | rcu_read_unlock(); |
5ab11c98 | 500 | fq->q.fragments = NULL; |
d6bebca9 | 501 | fq->q.fragments_tail = NULL; |
1da177e4 LT |
502 | return 1; |
503 | ||
504 | out_oversize: | |
e87cc472 | 505 | net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); |
1da177e4 LT |
506 | goto out_fail; |
507 | out_oom: | |
e87cc472 | 508 | net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); |
1da177e4 | 509 | out_fail: |
a11d206d | 510 | rcu_read_lock(); |
2bad35b7 | 511 | IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); |
a11d206d | 512 | rcu_read_unlock(); |
1da177e4 LT |
513 | return -1; |
514 | } | |
515 | ||
e5bbef20 | 516 | static int ipv6_frag_rcv(struct sk_buff *skb) |
1da177e4 | 517 | { |
1da177e4 LT |
518 | struct frag_hdr *fhdr; |
519 | struct frag_queue *fq; | |
b71d1d42 | 520 | const struct ipv6hdr *hdr = ipv6_hdr(skb); |
adf30907 | 521 | struct net *net = dev_net(skb_dst(skb)->dev); |
1da177e4 | 522 | |
f46078cf HFS |
523 | if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) |
524 | goto fail_hdr; | |
525 | ||
adf30907 | 526 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); |
1da177e4 LT |
527 | |
528 | /* Jumbo payload inhibits frag. header */ | |
98b3377c DL |
529 | if (hdr->payload_len==0) |
530 | goto fail_hdr; | |
531 | ||
ea2ae17d | 532 | if (!pskb_may_pull(skb, (skb_transport_offset(skb) + |
98b3377c DL |
533 | sizeof(struct frag_hdr)))) |
534 | goto fail_hdr; | |
1da177e4 | 535 | |
0660e03f | 536 | hdr = ipv6_hdr(skb); |
9c70220b | 537 | fhdr = (struct frag_hdr *)skb_transport_header(skb); |
1da177e4 LT |
538 | |
539 | if (!(fhdr->frag_off & htons(0xFFF9))) { | |
540 | /* It is not a fragmented frame */ | |
b0e380b1 | 541 | skb->transport_header += sizeof(struct frag_hdr); |
483a47d2 | 542 | IP6_INC_STATS_BH(net, |
adf30907 | 543 | ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); |
1da177e4 | 544 | |
d56f90a7 | 545 | IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); |
f46078cf | 546 | IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; |
1da177e4 LT |
547 | return 1; |
548 | } | |
549 | ||
eec2e618 HFS |
550 | fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr, |
551 | ip6_frag_ecn(hdr)); | |
9546377c | 552 | if (fq != NULL) { |
f61944ef | 553 | int ret; |
1da177e4 | 554 | |
5ab11c98 | 555 | spin_lock(&fq->q.lock); |
1da177e4 | 556 | |
f61944ef | 557 | ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff); |
1da177e4 | 558 | |
5ab11c98 | 559 | spin_unlock(&fq->q.lock); |
b836c99f | 560 | inet_frag_put(&fq->q, &ip6_frags); |
1da177e4 LT |
561 | return ret; |
562 | } | |
563 | ||
adf30907 | 564 | IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS); |
1da177e4 LT |
565 | kfree_skb(skb); |
566 | return -1; | |
98b3377c DL |
567 | |
568 | fail_hdr: | |
adf30907 | 569 | IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS); |
98b3377c DL |
570 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb)); |
571 | return -1; | |
1da177e4 LT |
572 | } |
573 | ||
41135cc8 | 574 | static const struct inet6_protocol frag_protocol = |
1da177e4 LT |
575 | { |
576 | .handler = ipv6_frag_rcv, | |
577 | .flags = INET6_PROTO_NOPOLICY, | |
578 | }; | |
579 | ||
8d8354d2 | 580 | #ifdef CONFIG_SYSCTL |
0a64b4b8 | 581 | static struct ctl_table ip6_frags_ns_ctl_table[] = { |
8d8354d2 | 582 | { |
8d8354d2 | 583 | .procname = "ip6frag_high_thresh", |
e31e0bdc | 584 | .data = &init_net.ipv6.frags.high_thresh, |
8d8354d2 PE |
585 | .maxlen = sizeof(int), |
586 | .mode = 0644, | |
6d9f239a | 587 | .proc_handler = proc_dointvec |
8d8354d2 PE |
588 | }, |
589 | { | |
8d8354d2 | 590 | .procname = "ip6frag_low_thresh", |
e31e0bdc | 591 | .data = &init_net.ipv6.frags.low_thresh, |
8d8354d2 PE |
592 | .maxlen = sizeof(int), |
593 | .mode = 0644, | |
6d9f239a | 594 | .proc_handler = proc_dointvec |
8d8354d2 PE |
595 | }, |
596 | { | |
8d8354d2 | 597 | .procname = "ip6frag_time", |
b2fd5321 | 598 | .data = &init_net.ipv6.frags.timeout, |
8d8354d2 PE |
599 | .maxlen = sizeof(int), |
600 | .mode = 0644, | |
6d9f239a | 601 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 | 602 | }, |
7d291ebb PE |
603 | { } |
604 | }; | |
605 | ||
606 | static struct ctl_table ip6_frags_ctl_table[] = { | |
8d8354d2 | 607 | { |
8d8354d2 | 608 | .procname = "ip6frag_secret_interval", |
3b4bc4a2 | 609 | .data = &ip6_frags.secret_interval, |
8d8354d2 PE |
610 | .maxlen = sizeof(int), |
611 | .mode = 0644, | |
6d9f239a | 612 | .proc_handler = proc_dointvec_jiffies, |
8d8354d2 PE |
613 | }, |
614 | { } | |
615 | }; | |
616 | ||
2c8c1e72 | 617 | static int __net_init ip6_frags_ns_sysctl_register(struct net *net) |
8d8354d2 | 618 | { |
e4a2d5c2 | 619 | struct ctl_table *table; |
8d8354d2 PE |
620 | struct ctl_table_header *hdr; |
621 | ||
0a64b4b8 | 622 | table = ip6_frags_ns_ctl_table; |
09ad9bc7 | 623 | if (!net_eq(net, &init_net)) { |
0a64b4b8 | 624 | table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL); |
e4a2d5c2 PE |
625 | if (table == NULL) |
626 | goto err_alloc; | |
627 | ||
e31e0bdc PE |
628 | table[0].data = &net->ipv6.frags.high_thresh; |
629 | table[1].data = &net->ipv6.frags.low_thresh; | |
b2fd5321 | 630 | table[2].data = &net->ipv6.frags.timeout; |
464dc801 EB |
631 | |
632 | /* Don't export sysctls to unprivileged users */ | |
633 | if (net->user_ns != &init_user_ns) | |
634 | table[0].procname = NULL; | |
e4a2d5c2 PE |
635 | } |
636 | ||
ec8f23ce | 637 | hdr = register_net_sysctl(net, "net/ipv6", table); |
e4a2d5c2 PE |
638 | if (hdr == NULL) |
639 | goto err_reg; | |
640 | ||
641 | net->ipv6.sysctl.frags_hdr = hdr; | |
642 | return 0; | |
643 | ||
644 | err_reg: | |
09ad9bc7 | 645 | if (!net_eq(net, &init_net)) |
e4a2d5c2 PE |
646 | kfree(table); |
647 | err_alloc: | |
648 | return -ENOMEM; | |
649 | } | |
650 | ||
2c8c1e72 | 651 | static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
652 | { |
653 | struct ctl_table *table; | |
654 | ||
655 | table = net->ipv6.sysctl.frags_hdr->ctl_table_arg; | |
656 | unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr); | |
3705e11a YH |
657 | if (!net_eq(net, &init_net)) |
658 | kfree(table); | |
8d8354d2 | 659 | } |
7d291ebb PE |
660 | |
661 | static struct ctl_table_header *ip6_ctl_header; | |
662 | ||
663 | static int ip6_frags_sysctl_register(void) | |
664 | { | |
43444757 | 665 | ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6", |
7d291ebb PE |
666 | ip6_frags_ctl_table); |
667 | return ip6_ctl_header == NULL ? -ENOMEM : 0; | |
668 | } | |
669 | ||
670 | static void ip6_frags_sysctl_unregister(void) | |
671 | { | |
672 | unregister_net_sysctl_table(ip6_ctl_header); | |
673 | } | |
8d8354d2 | 674 | #else |
0a64b4b8 | 675 | static inline int ip6_frags_ns_sysctl_register(struct net *net) |
e71e0349 | 676 | { |
8d8354d2 PE |
677 | return 0; |
678 | } | |
e4a2d5c2 | 679 | |
0a64b4b8 | 680 | static inline void ip6_frags_ns_sysctl_unregister(struct net *net) |
e4a2d5c2 PE |
681 | { |
682 | } | |
7d291ebb PE |
683 | |
684 | static inline int ip6_frags_sysctl_register(void) | |
685 | { | |
686 | return 0; | |
687 | } | |
688 | ||
689 | static inline void ip6_frags_sysctl_unregister(void) | |
690 | { | |
691 | } | |
8d8354d2 | 692 | #endif |
7d460db9 | 693 | |
2c8c1e72 | 694 | static int __net_init ipv6_frags_init_net(struct net *net) |
8d8354d2 | 695 | { |
7c070aa9 SW |
696 | net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; |
697 | net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH; | |
b2fd5321 | 698 | net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT; |
8d8354d2 | 699 | |
e5a2bb84 PE |
700 | inet_frags_init_net(&net->ipv6.frags); |
701 | ||
0a64b4b8 | 702 | return ip6_frags_ns_sysctl_register(net); |
e71e0349 DL |
703 | } |
704 | ||
2c8c1e72 | 705 | static void __net_exit ipv6_frags_exit_net(struct net *net) |
81566e83 | 706 | { |
0a64b4b8 | 707 | ip6_frags_ns_sysctl_unregister(net); |
81566e83 PE |
708 | inet_frags_exit_net(&net->ipv6.frags, &ip6_frags); |
709 | } | |
710 | ||
711 | static struct pernet_operations ip6_frags_ops = { | |
712 | .init = ipv6_frags_init_net, | |
713 | .exit = ipv6_frags_exit_net, | |
714 | }; | |
715 | ||
853cbbaa | 716 | int __init ipv6_frag_init(void) |
1da177e4 | 717 | { |
853cbbaa | 718 | int ret; |
1da177e4 | 719 | |
853cbbaa DL |
720 | ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
721 | if (ret) | |
722 | goto out; | |
e71e0349 | 723 | |
7d291ebb PE |
724 | ret = ip6_frags_sysctl_register(); |
725 | if (ret) | |
726 | goto err_sysctl; | |
727 | ||
0002c630 PE |
728 | ret = register_pernet_subsys(&ip6_frags_ops); |
729 | if (ret) | |
730 | goto err_pernet; | |
8d8354d2 | 731 | |
321a3a99 | 732 | ip6_frags.hashfn = ip6_hashfn; |
c6fda282 | 733 | ip6_frags.constructor = ip6_frag_init; |
c9547709 | 734 | ip6_frags.destructor = NULL; |
1e4b8287 PE |
735 | ip6_frags.skb_free = NULL; |
736 | ip6_frags.qsize = sizeof(struct frag_queue); | |
abd6523d | 737 | ip6_frags.match = ip6_frag_match; |
e521db9d | 738 | ip6_frags.frag_expire = ip6_frag_expire; |
3b4bc4a2 | 739 | ip6_frags.secret_interval = 10 * 60 * HZ; |
7eb95156 | 740 | inet_frags_init(&ip6_frags); |
853cbbaa DL |
741 | out: |
742 | return ret; | |
0002c630 PE |
743 | |
744 | err_pernet: | |
7d291ebb PE |
745 | ip6_frags_sysctl_unregister(); |
746 | err_sysctl: | |
0002c630 PE |
747 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
748 | goto out; | |
853cbbaa DL |
749 | } |
750 | ||
751 | void ipv6_frag_exit(void) | |
752 | { | |
753 | inet_frags_fini(&ip6_frags); | |
7d291ebb | 754 | ip6_frags_sysctl_unregister(); |
81566e83 | 755 | unregister_pernet_subsys(&ip6_frags_ops); |
853cbbaa | 756 | inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT); |
1da177e4 | 757 | } |