ia64/linux-2.6.18-xen.hg

view net/ipv6/reassembly.c @ 673:3161879fdf22

[IA64] xencomm: support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap

support XENMEM_add_to_physmap and XENMEM_remove_from_phsymap.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Tue Sep 16 21:26:15 2008 +0900 (2008-09-16)
parents 831230e53067
children
line source
1 /*
2 * IPv6 fragment reassembly
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * $Id: reassembly.c,v 1.26 2001/03/07 22:00:57 davem Exp $
9 *
10 * Based on: net/ipv4/ip_fragment.c
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
18 /*
19 * Fixes:
20 * Andi Kleen Make it work with multiple hosts.
21 * More RFC compliance.
22 *
23 * Horst von Brand Add missing #include <linux/string.h>
24 * Alexey Kuznetsov SMP races, threading, cleanup.
25 * Patrick McHardy LRU queue of frag heads for evictor.
26 * Mitsuru KANDA @USAGI Register inet6_protocol{}.
27 * David Stevens and
28 * YOSHIFUJI,H. @USAGI Always remove fragment header to
29 * calculate ICV correctly.
30 */
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/string.h>
34 #include <linux/socket.h>
35 #include <linux/sockios.h>
36 #include <linux/jiffies.h>
37 #include <linux/net.h>
38 #include <linux/list.h>
39 #include <linux/netdevice.h>
40 #include <linux/in6.h>
41 #include <linux/ipv6.h>
42 #include <linux/icmpv6.h>
43 #include <linux/random.h>
44 #include <linux/jhash.h>
46 #include <net/sock.h>
47 #include <net/snmp.h>
49 #include <net/ipv6.h>
50 #include <net/protocol.h>
51 #include <net/transp_v6.h>
52 #include <net/rawv6.h>
53 #include <net/ndisc.h>
54 #include <net/addrconf.h>
56 int sysctl_ip6frag_high_thresh = 256*1024;
57 int sysctl_ip6frag_low_thresh = 192*1024;
59 int sysctl_ip6frag_time = IPV6_FRAG_TIMEOUT;
61 struct ip6frag_skb_cb
62 {
63 struct inet6_skb_parm h;
64 int offset;
65 };
67 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb))
70 /*
71 * Equivalent of ipv4 struct ipq
72 */
74 struct frag_queue
75 {
76 struct hlist_node list;
77 struct list_head lru_list; /* lru list member */
79 __u32 id; /* fragment id */
80 struct in6_addr saddr;
81 struct in6_addr daddr;
83 spinlock_t lock;
84 atomic_t refcnt;
85 struct timer_list timer; /* expire timer */
86 struct sk_buff *fragments;
87 int len;
88 int meat;
89 int iif;
90 struct timeval stamp;
91 unsigned int csum;
92 __u8 last_in; /* has first/last segment arrived? */
93 #define COMPLETE 4
94 #define FIRST_IN 2
95 #define LAST_IN 1
96 __u16 nhoffset;
97 };
99 /* Hash table. */
101 #define IP6Q_HASHSZ 64
103 static struct hlist_head ip6_frag_hash[IP6Q_HASHSZ];
104 static DEFINE_RWLOCK(ip6_frag_lock);
105 static u32 ip6_frag_hash_rnd;
106 static LIST_HEAD(ip6_frag_lru_list);
107 int ip6_frag_nqueues = 0;
109 static __inline__ void __fq_unlink(struct frag_queue *fq)
110 {
111 hlist_del(&fq->list);
112 list_del(&fq->lru_list);
113 ip6_frag_nqueues--;
114 }
116 static __inline__ void fq_unlink(struct frag_queue *fq)
117 {
118 write_lock(&ip6_frag_lock);
119 __fq_unlink(fq);
120 write_unlock(&ip6_frag_lock);
121 }
123 /*
124 * callers should be careful not to use the hash value outside the ipfrag_lock
125 * as doing so could race with ipfrag_hash_rnd being recalculated.
126 */
127 static unsigned int ip6qhashfn(u32 id, struct in6_addr *saddr,
128 struct in6_addr *daddr)
129 {
130 u32 a, b, c;
132 a = saddr->s6_addr32[0];
133 b = saddr->s6_addr32[1];
134 c = saddr->s6_addr32[2];
136 a += JHASH_GOLDEN_RATIO;
137 b += JHASH_GOLDEN_RATIO;
138 c += ip6_frag_hash_rnd;
139 __jhash_mix(a, b, c);
141 a += saddr->s6_addr32[3];
142 b += daddr->s6_addr32[0];
143 c += daddr->s6_addr32[1];
144 __jhash_mix(a, b, c);
146 a += daddr->s6_addr32[2];
147 b += daddr->s6_addr32[3];
148 c += id;
149 __jhash_mix(a, b, c);
151 return c & (IP6Q_HASHSZ - 1);
152 }
154 static struct timer_list ip6_frag_secret_timer;
155 int sysctl_ip6frag_secret_interval = 10 * 60 * HZ;
157 static void ip6_frag_secret_rebuild(unsigned long dummy)
158 {
159 unsigned long now = jiffies;
160 int i;
162 write_lock(&ip6_frag_lock);
163 get_random_bytes(&ip6_frag_hash_rnd, sizeof(u32));
164 for (i = 0; i < IP6Q_HASHSZ; i++) {
165 struct frag_queue *q;
166 struct hlist_node *p, *n;
168 hlist_for_each_entry_safe(q, p, n, &ip6_frag_hash[i], list) {
169 unsigned int hval = ip6qhashfn(q->id,
170 &q->saddr,
171 &q->daddr);
173 if (hval != i) {
174 hlist_del(&q->list);
176 /* Relink to new hash chain. */
177 hlist_add_head(&q->list,
178 &ip6_frag_hash[hval]);
180 }
181 }
182 }
183 write_unlock(&ip6_frag_lock);
185 mod_timer(&ip6_frag_secret_timer, now + sysctl_ip6frag_secret_interval);
186 }
188 atomic_t ip6_frag_mem = ATOMIC_INIT(0);
190 /* Memory Tracking Functions. */
191 static inline void frag_kfree_skb(struct sk_buff *skb, int *work)
192 {
193 if (work)
194 *work -= skb->truesize;
195 atomic_sub(skb->truesize, &ip6_frag_mem);
196 kfree_skb(skb);
197 }
199 static inline void frag_free_queue(struct frag_queue *fq, int *work)
200 {
201 if (work)
202 *work -= sizeof(struct frag_queue);
203 atomic_sub(sizeof(struct frag_queue), &ip6_frag_mem);
204 kfree(fq);
205 }
207 static inline struct frag_queue *frag_alloc_queue(void)
208 {
209 struct frag_queue *fq = kzalloc(sizeof(struct frag_queue), GFP_ATOMIC);
211 if(!fq)
212 return NULL;
213 atomic_add(sizeof(struct frag_queue), &ip6_frag_mem);
214 return fq;
215 }
217 /* Destruction primitives. */
219 /* Complete destruction of fq. */
220 static void ip6_frag_destroy(struct frag_queue *fq, int *work)
221 {
222 struct sk_buff *fp;
224 BUG_TRAP(fq->last_in&COMPLETE);
225 BUG_TRAP(del_timer(&fq->timer) == 0);
227 /* Release all fragment data. */
228 fp = fq->fragments;
229 while (fp) {
230 struct sk_buff *xp = fp->next;
232 frag_kfree_skb(fp, work);
233 fp = xp;
234 }
236 frag_free_queue(fq, work);
237 }
239 static __inline__ void fq_put(struct frag_queue *fq, int *work)
240 {
241 if (atomic_dec_and_test(&fq->refcnt))
242 ip6_frag_destroy(fq, work);
243 }
245 /* Kill fq entry. It is not destroyed immediately,
246 * because caller (and someone more) holds reference count.
247 */
248 static __inline__ void fq_kill(struct frag_queue *fq)
249 {
250 if (del_timer(&fq->timer))
251 atomic_dec(&fq->refcnt);
253 if (!(fq->last_in & COMPLETE)) {
254 fq_unlink(fq);
255 atomic_dec(&fq->refcnt);
256 fq->last_in |= COMPLETE;
257 }
258 }
260 static void ip6_evictor(void)
261 {
262 struct frag_queue *fq;
263 struct list_head *tmp;
264 int work;
266 work = atomic_read(&ip6_frag_mem) - sysctl_ip6frag_low_thresh;
267 if (work <= 0)
268 return;
270 while(work > 0) {
271 read_lock(&ip6_frag_lock);
272 if (list_empty(&ip6_frag_lru_list)) {
273 read_unlock(&ip6_frag_lock);
274 return;
275 }
276 tmp = ip6_frag_lru_list.next;
277 fq = list_entry(tmp, struct frag_queue, lru_list);
278 atomic_inc(&fq->refcnt);
279 read_unlock(&ip6_frag_lock);
281 spin_lock(&fq->lock);
282 if (!(fq->last_in&COMPLETE))
283 fq_kill(fq);
284 spin_unlock(&fq->lock);
286 fq_put(fq, &work);
287 IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
288 }
289 }
291 static void ip6_frag_expire(unsigned long data)
292 {
293 struct frag_queue *fq = (struct frag_queue *) data;
294 struct net_device *dev;
296 spin_lock(&fq->lock);
298 if (fq->last_in & COMPLETE)
299 goto out;
301 fq_kill(fq);
303 IP6_INC_STATS_BH(IPSTATS_MIB_REASMTIMEOUT);
304 IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
306 /* Don't send error if the first segment did not arrive. */
307 if (!(fq->last_in&FIRST_IN) || !fq->fragments)
308 goto out;
310 dev = dev_get_by_index(fq->iif);
311 if (!dev)
312 goto out;
314 /*
315 But use as source device on which LAST ARRIVED
316 segment was received. And do not use fq->dev
317 pointer directly, device might already disappeared.
318 */
319 fq->fragments->dev = dev;
320 icmpv6_send(fq->fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
321 dev_put(dev);
322 out:
323 spin_unlock(&fq->lock);
324 fq_put(fq, NULL);
325 }
327 /* Creation primitives. */
330 static struct frag_queue *ip6_frag_intern(struct frag_queue *fq_in)
331 {
332 struct frag_queue *fq;
333 unsigned int hash;
334 #ifdef CONFIG_SMP
335 struct hlist_node *n;
336 #endif
338 write_lock(&ip6_frag_lock);
339 hash = ip6qhashfn(fq_in->id, &fq_in->saddr, &fq_in->daddr);
340 #ifdef CONFIG_SMP
341 hlist_for_each_entry(fq, n, &ip6_frag_hash[hash], list) {
342 if (fq->id == fq_in->id &&
343 ipv6_addr_equal(&fq_in->saddr, &fq->saddr) &&
344 ipv6_addr_equal(&fq_in->daddr, &fq->daddr)) {
345 atomic_inc(&fq->refcnt);
346 write_unlock(&ip6_frag_lock);
347 fq_in->last_in |= COMPLETE;
348 fq_put(fq_in, NULL);
349 return fq;
350 }
351 }
352 #endif
353 fq = fq_in;
355 if (!mod_timer(&fq->timer, jiffies + sysctl_ip6frag_time))
356 atomic_inc(&fq->refcnt);
358 atomic_inc(&fq->refcnt);
359 hlist_add_head(&fq->list, &ip6_frag_hash[hash]);
360 INIT_LIST_HEAD(&fq->lru_list);
361 list_add_tail(&fq->lru_list, &ip6_frag_lru_list);
362 ip6_frag_nqueues++;
363 write_unlock(&ip6_frag_lock);
364 return fq;
365 }
368 static struct frag_queue *
369 ip6_frag_create(u32 id, struct in6_addr *src, struct in6_addr *dst)
370 {
371 struct frag_queue *fq;
373 if ((fq = frag_alloc_queue()) == NULL)
374 goto oom;
376 fq->id = id;
377 ipv6_addr_copy(&fq->saddr, src);
378 ipv6_addr_copy(&fq->daddr, dst);
380 init_timer(&fq->timer);
381 fq->timer.function = ip6_frag_expire;
382 fq->timer.data = (long) fq;
383 spin_lock_init(&fq->lock);
384 atomic_set(&fq->refcnt, 1);
386 return ip6_frag_intern(fq);
388 oom:
389 IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
390 return NULL;
391 }
393 static __inline__ struct frag_queue *
394 fq_find(u32 id, struct in6_addr *src, struct in6_addr *dst)
395 {
396 struct frag_queue *fq;
397 struct hlist_node *n;
398 unsigned int hash;
400 read_lock(&ip6_frag_lock);
401 hash = ip6qhashfn(id, src, dst);
402 hlist_for_each_entry(fq, n, &ip6_frag_hash[hash], list) {
403 if (fq->id == id &&
404 ipv6_addr_equal(src, &fq->saddr) &&
405 ipv6_addr_equal(dst, &fq->daddr)) {
406 atomic_inc(&fq->refcnt);
407 read_unlock(&ip6_frag_lock);
408 return fq;
409 }
410 }
411 read_unlock(&ip6_frag_lock);
413 return ip6_frag_create(id, src, dst);
414 }
417 static void ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
418 struct frag_hdr *fhdr, int nhoff)
419 {
420 struct sk_buff *prev, *next;
421 int offset, end;
423 if (fq->last_in & COMPLETE)
424 goto err;
426 offset = ntohs(fhdr->frag_off) & ~0x7;
427 end = offset + (ntohs(skb->nh.ipv6h->payload_len) -
428 ((u8 *) (fhdr + 1) - (u8 *) (skb->nh.ipv6h + 1)));
430 if ((unsigned int)end > IPV6_MAXPLEN) {
431 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
432 icmpv6_param_prob(skb,ICMPV6_HDR_FIELD, (u8*)&fhdr->frag_off - skb->nh.raw);
433 return;
434 }
436 if (skb->ip_summed == CHECKSUM_HW)
437 skb->csum = csum_sub(skb->csum,
438 csum_partial(skb->nh.raw, (u8*)(fhdr+1)-skb->nh.raw, 0));
440 /* Is this the final fragment? */
441 if (!(fhdr->frag_off & htons(IP6_MF))) {
442 /* If we already have some bits beyond end
443 * or have different end, the segment is corrupted.
444 */
445 if (end < fq->len ||
446 ((fq->last_in & LAST_IN) && end != fq->len))
447 goto err;
448 fq->last_in |= LAST_IN;
449 fq->len = end;
450 } else {
451 /* Check if the fragment is rounded to 8 bytes.
452 * Required by the RFC.
453 */
454 if (end & 0x7) {
455 /* RFC2460 says always send parameter problem in
456 * this case. -DaveM
457 */
458 IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
459 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
460 offsetof(struct ipv6hdr, payload_len));
461 return;
462 }
463 if (end > fq->len) {
464 /* Some bits beyond end -> corruption. */
465 if (fq->last_in & LAST_IN)
466 goto err;
467 fq->len = end;
468 }
469 }
471 if (end == offset)
472 goto err;
474 /* Point into the IP datagram 'data' part. */
475 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
476 goto err;
478 if (pskb_trim_rcsum(skb, end - offset))
479 goto err;
481 /* Find out which fragments are in front and at the back of us
482 * in the chain of fragments so far. We must know where to put
483 * this fragment, right?
484 */
485 prev = NULL;
486 for(next = fq->fragments; next != NULL; next = next->next) {
487 if (FRAG6_CB(next)->offset >= offset)
488 break; /* bingo! */
489 prev = next;
490 }
492 /* We found where to put this one. Check for overlap with
493 * preceding fragment, and, if needed, align things so that
494 * any overlaps are eliminated.
495 */
496 if (prev) {
497 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
499 if (i > 0) {
500 offset += i;
501 if (end <= offset)
502 goto err;
503 if (!pskb_pull(skb, i))
504 goto err;
505 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
506 skb->ip_summed = CHECKSUM_NONE;
507 }
508 }
510 /* Look for overlap with succeeding segments.
511 * If we can merge fragments, do it.
512 */
513 while (next && FRAG6_CB(next)->offset < end) {
514 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
516 if (i < next->len) {
517 /* Eat head of the next overlapped fragment
518 * and leave the loop. The next ones cannot overlap.
519 */
520 if (!pskb_pull(next, i))
521 goto err;
522 FRAG6_CB(next)->offset += i; /* next fragment */
523 fq->meat -= i;
524 if (next->ip_summed != CHECKSUM_UNNECESSARY)
525 next->ip_summed = CHECKSUM_NONE;
526 break;
527 } else {
528 struct sk_buff *free_it = next;
530 /* Old fragment is completely overridden with
531 * new one drop it.
532 */
533 next = next->next;
535 if (prev)
536 prev->next = next;
537 else
538 fq->fragments = next;
540 fq->meat -= free_it->len;
541 frag_kfree_skb(free_it, NULL);
542 }
543 }
545 FRAG6_CB(skb)->offset = offset;
547 /* Insert this fragment in the chain of fragments. */
548 skb->next = next;
549 if (prev)
550 prev->next = skb;
551 else
552 fq->fragments = skb;
554 if (skb->dev)
555 fq->iif = skb->dev->ifindex;
556 skb->dev = NULL;
557 skb_get_timestamp(skb, &fq->stamp);
558 fq->meat += skb->len;
559 atomic_add(skb->truesize, &ip6_frag_mem);
561 /* The first fragment.
562 * nhoffset is obtained from the first fragment, of course.
563 */
564 if (offset == 0) {
565 fq->nhoffset = nhoff;
566 fq->last_in |= FIRST_IN;
567 }
568 write_lock(&ip6_frag_lock);
569 list_move_tail(&fq->lru_list, &ip6_frag_lru_list);
570 write_unlock(&ip6_frag_lock);
571 return;
573 err:
574 IP6_INC_STATS(IPSTATS_MIB_REASMFAILS);
575 kfree_skb(skb);
576 }
578 /*
579 * Check if this packet is complete.
580 * Returns NULL on failure by any reason, and pointer
581 * to current nexthdr field in reassembled frame.
582 *
583 * It is called with locked fq, and caller must check that
584 * queue is eligible for reassembly i.e. it is not COMPLETE,
585 * the last and the first frames arrived and all the bits are here.
586 */
587 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff **skb_in,
588 struct net_device *dev)
589 {
590 struct sk_buff *fp, *head = fq->fragments;
591 int payload_len;
592 unsigned int nhoff;
594 fq_kill(fq);
596 BUG_TRAP(head != NULL);
597 BUG_TRAP(FRAG6_CB(head)->offset == 0);
599 /* Unfragmented part is taken from the first segment. */
600 payload_len = (head->data - head->nh.raw) - sizeof(struct ipv6hdr) + fq->len - sizeof(struct frag_hdr);
601 if (payload_len > IPV6_MAXPLEN)
602 goto out_oversize;
604 /* Head of list must not be cloned. */
605 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
606 goto out_oom;
608 /* If the first fragment is fragmented itself, we split
609 * it to two chunks: the first with data and paged part
610 * and the second, holding only fragments. */
611 if (skb_shinfo(head)->frag_list) {
612 struct sk_buff *clone;
613 int i, plen = 0;
615 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
616 goto out_oom;
617 clone->next = head->next;
618 head->next = clone;
619 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
620 skb_shinfo(head)->frag_list = NULL;
621 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
622 plen += skb_shinfo(head)->frags[i].size;
623 clone->len = clone->data_len = head->data_len - plen;
624 head->data_len -= clone->len;
625 head->len -= clone->len;
626 clone->csum = 0;
627 clone->ip_summed = head->ip_summed;
628 atomic_add(clone->truesize, &ip6_frag_mem);
629 }
631 /* We have to remove fragment header from datagram and to relocate
632 * header in order to calculate ICV correctly. */
633 nhoff = fq->nhoffset;
634 head->nh.raw[nhoff] = head->h.raw[0];
635 memmove(head->head + sizeof(struct frag_hdr), head->head,
636 (head->data - head->head) - sizeof(struct frag_hdr));
637 head->mac.raw += sizeof(struct frag_hdr);
638 head->nh.raw += sizeof(struct frag_hdr);
640 skb_shinfo(head)->frag_list = head->next;
641 head->h.raw = head->data;
642 skb_push(head, head->data - head->nh.raw);
643 atomic_sub(head->truesize, &ip6_frag_mem);
645 for (fp=head->next; fp; fp = fp->next) {
646 head->data_len += fp->len;
647 head->len += fp->len;
648 if (head->ip_summed != fp->ip_summed)
649 head->ip_summed = CHECKSUM_NONE;
650 else if (head->ip_summed == CHECKSUM_HW)
651 head->csum = csum_add(head->csum, fp->csum);
652 head->truesize += fp->truesize;
653 atomic_sub(fp->truesize, &ip6_frag_mem);
654 }
656 head->next = NULL;
657 head->dev = dev;
658 skb_set_timestamp(head, &fq->stamp);
659 head->nh.ipv6h->payload_len = htons(payload_len);
660 IP6CB(head)->nhoff = nhoff;
662 *skb_in = head;
664 /* Yes, and fold redundant checksum back. 8) */
665 if (head->ip_summed == CHECKSUM_HW)
666 head->csum = csum_partial(head->nh.raw, head->h.raw-head->nh.raw, head->csum);
668 IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
669 fq->fragments = NULL;
670 return 1;
672 out_oversize:
673 if (net_ratelimit())
674 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
675 goto out_fail;
676 out_oom:
677 if (net_ratelimit())
678 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
679 out_fail:
680 IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
681 return -1;
682 }
684 static int ipv6_frag_rcv(struct sk_buff **skbp)
685 {
686 struct sk_buff *skb = *skbp;
687 struct net_device *dev = skb->dev;
688 struct frag_hdr *fhdr;
689 struct frag_queue *fq;
690 struct ipv6hdr *hdr;
692 hdr = skb->nh.ipv6h;
694 IP6_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
696 /* Jumbo payload inhibits frag. header */
697 if (hdr->payload_len==0) {
698 IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
699 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
700 return -1;
701 }
702 if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+sizeof(struct frag_hdr))) {
703 IP6_INC_STATS(IPSTATS_MIB_INHDRERRORS);
704 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb->h.raw-skb->nh.raw);
705 return -1;
706 }
708 hdr = skb->nh.ipv6h;
709 fhdr = (struct frag_hdr *)skb->h.raw;
711 if (!(fhdr->frag_off & htons(0xFFF9))) {
712 /* It is not a fragmented frame */
713 skb->h.raw += sizeof(struct frag_hdr);
714 IP6_INC_STATS_BH(IPSTATS_MIB_REASMOKS);
716 IP6CB(skb)->nhoff = (u8*)fhdr - skb->nh.raw;
717 return 1;
718 }
720 if (atomic_read(&ip6_frag_mem) > sysctl_ip6frag_high_thresh)
721 ip6_evictor();
723 if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr)) != NULL) {
724 int ret = -1;
726 spin_lock(&fq->lock);
728 ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
730 if (fq->last_in == (FIRST_IN|LAST_IN) &&
731 fq->meat == fq->len)
732 ret = ip6_frag_reasm(fq, skbp, dev);
734 spin_unlock(&fq->lock);
735 fq_put(fq, NULL);
736 return ret;
737 }
739 IP6_INC_STATS_BH(IPSTATS_MIB_REASMFAILS);
740 kfree_skb(skb);
741 return -1;
742 }
744 static struct inet6_protocol frag_protocol =
745 {
746 .handler = ipv6_frag_rcv,
747 .flags = INET6_PROTO_NOPOLICY,
748 };
750 void __init ipv6_frag_init(void)
751 {
752 if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0)
753 printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n");
755 ip6_frag_hash_rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
756 (jiffies ^ (jiffies >> 6)));
758 init_timer(&ip6_frag_secret_timer);
759 ip6_frag_secret_timer.function = ip6_frag_secret_rebuild;
760 ip6_frag_secret_timer.expires = jiffies + sysctl_ip6frag_secret_interval;
761 add_timer(&ip6_frag_secret_timer);
762 }