powerpc/powernv: Report size of OPAL memcons log
[linux/fpc-iii.git] / net / ipv4 / ip_fragment.c
blobbbe7f72db9c157ba2d6c5292637c2f58ad39a123
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * The IP fragmentation functionality.
8 * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
9 * Alan Cox <alan@lxorguk.ukuu.org.uk>
11 * Fixes:
12 * Alan Cox : Split from ip.c , see ip_input.c for history.
13 * David S. Miller : Begin massive cleanup...
14 * Andi Kleen : Add sysctls.
15 * xxxx : Overlapfrag bug.
16 * Ultima : ip_expire() kernel panic.
17 * Bill Hawes : Frag accounting and evictor fixes.
18 * John McDonald : 0 length frag bug.
19 * Alexey Kuznetsov: SMP races, threading, cleanup.
20 * Patrick McHardy : LRU queue of frag heads for evictor.
23 #define pr_fmt(fmt) "IPv4: " fmt
25 #include <linux/compiler.h>
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/mm.h>
29 #include <linux/jiffies.h>
30 #include <linux/skbuff.h>
31 #include <linux/list.h>
32 #include <linux/ip.h>
33 #include <linux/icmp.h>
34 #include <linux/netdevice.h>
35 #include <linux/jhash.h>
36 #include <linux/random.h>
37 #include <linux/slab.h>
38 #include <net/route.h>
39 #include <net/dst.h>
40 #include <net/sock.h>
41 #include <net/ip.h>
42 #include <net/icmp.h>
43 #include <net/checksum.h>
44 #include <net/inetpeer.h>
45 #include <net/inet_frag.h>
46 #include <linux/tcp.h>
47 #include <linux/udp.h>
48 #include <linux/inet.h>
49 #include <linux/netfilter_ipv4.h>
50 #include <net/inet_ecn.h>
51 #include <net/l3mdev.h>
53 /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
54 * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
55 * as well. Or notify me, at least. --ANK
57 static const char ip_frag_cache_name[] = "ip4-frags";
59 struct ipfrag_skb_cb
61 struct inet_skb_parm h;
62 int offset;
65 #define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
67 /* Describe an entry in the "incomplete datagrams" queue. */
68 struct ipq {
69 struct inet_frag_queue q;
71 u32 user;
72 __be32 saddr;
73 __be32 daddr;
74 __be16 id;
75 u8 protocol;
76 u8 ecn; /* RFC3168 support */
77 u16 max_df_size; /* largest frag with DF set seen */
78 int iif;
79 int vif; /* L3 master device index */
80 unsigned int rid;
81 struct inet_peer *peer;
84 static u8 ip4_frag_ecn(u8 tos)
86 return 1 << (tos & INET_ECN_MASK);
89 static struct inet_frags ip4_frags;
91 int ip_frag_mem(struct net *net)
93 return sum_frag_mem_limit(&net->ipv4.frags);
96 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
97 struct net_device *dev);
99 struct ip4_create_arg {
100 struct iphdr *iph;
101 u32 user;
102 int vif;
105 static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
107 net_get_random_once(&ip4_frags.rnd, sizeof(ip4_frags.rnd));
108 return jhash_3words((__force u32)id << 16 | prot,
109 (__force u32)saddr, (__force u32)daddr,
110 ip4_frags.rnd);
113 static unsigned int ip4_hashfn(const struct inet_frag_queue *q)
115 const struct ipq *ipq;
117 ipq = container_of(q, struct ipq, q);
118 return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
121 static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a)
123 const struct ipq *qp;
124 const struct ip4_create_arg *arg = a;
126 qp = container_of(q, struct ipq, q);
127 return qp->id == arg->iph->id &&
128 qp->saddr == arg->iph->saddr &&
129 qp->daddr == arg->iph->daddr &&
130 qp->protocol == arg->iph->protocol &&
131 qp->user == arg->user &&
132 qp->vif == arg->vif;
135 static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
137 struct ipq *qp = container_of(q, struct ipq, q);
138 struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4,
139 frags);
140 struct net *net = container_of(ipv4, struct net, ipv4);
142 const struct ip4_create_arg *arg = a;
144 qp->protocol = arg->iph->protocol;
145 qp->id = arg->iph->id;
146 qp->ecn = ip4_frag_ecn(arg->iph->tos);
147 qp->saddr = arg->iph->saddr;
148 qp->daddr = arg->iph->daddr;
149 qp->vif = arg->vif;
150 qp->user = arg->user;
151 qp->peer = q->net->max_dist ?
152 inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, arg->vif, 1) :
153 NULL;
156 static void ip4_frag_free(struct inet_frag_queue *q)
158 struct ipq *qp;
160 qp = container_of(q, struct ipq, q);
161 if (qp->peer)
162 inet_putpeer(qp->peer);
166 /* Destruction primitives. */
168 static void ipq_put(struct ipq *ipq)
170 inet_frag_put(&ipq->q, &ip4_frags);
173 /* Kill ipq entry. It is not destroyed immediately,
174 * because caller (and someone more) holds reference count.
176 static void ipq_kill(struct ipq *ipq)
178 inet_frag_kill(&ipq->q, &ip4_frags);
181 static bool frag_expire_skip_icmp(u32 user)
183 return user == IP_DEFRAG_AF_PACKET ||
184 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
185 __IP_DEFRAG_CONNTRACK_IN_END) ||
186 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
187 __IP_DEFRAG_CONNTRACK_BRIDGE_IN);
191 * Oops, a fragment queue timed out. Kill it and send an ICMP reply.
193 static void ip_expire(unsigned long arg)
195 struct ipq *qp;
196 struct net *net;
198 qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
199 net = container_of(qp->q.net, struct net, ipv4.frags);
201 spin_lock(&qp->q.lock);
203 if (qp->q.flags & INET_FRAG_COMPLETE)
204 goto out;
206 ipq_kill(qp);
207 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
209 if (!inet_frag_evicting(&qp->q)) {
210 struct sk_buff *head = qp->q.fragments;
211 const struct iphdr *iph;
212 int err;
214 __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
216 if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !qp->q.fragments)
217 goto out;
219 rcu_read_lock();
220 head->dev = dev_get_by_index_rcu(net, qp->iif);
221 if (!head->dev)
222 goto out_rcu_unlock;
224 /* skb has no dst, perform route lookup again */
225 iph = ip_hdr(head);
226 err = ip_route_input_noref(head, iph->daddr, iph->saddr,
227 iph->tos, head->dev);
228 if (err)
229 goto out_rcu_unlock;
231 /* Only an end host needs to send an ICMP
232 * "Fragment Reassembly Timeout" message, per RFC792.
234 if (frag_expire_skip_icmp(qp->user) &&
235 (skb_rtable(head)->rt_type != RTN_LOCAL))
236 goto out_rcu_unlock;
238 /* Send an ICMP "Fragment Reassembly Timeout" message. */
239 icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
240 out_rcu_unlock:
241 rcu_read_unlock();
243 out:
244 spin_unlock(&qp->q.lock);
245 ipq_put(qp);
248 /* Find the correct entry in the "incomplete datagrams" queue for
249 * this IP datagram, and create new one, if nothing is found.
251 static struct ipq *ip_find(struct net *net, struct iphdr *iph,
252 u32 user, int vif)
254 struct inet_frag_queue *q;
255 struct ip4_create_arg arg;
256 unsigned int hash;
258 arg.iph = iph;
259 arg.user = user;
260 arg.vif = vif;
262 hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
264 q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
265 if (IS_ERR_OR_NULL(q)) {
266 inet_frag_maybe_warn_overflow(q, pr_fmt());
267 return NULL;
269 return container_of(q, struct ipq, q);
272 /* Is the fragment too far ahead to be part of ipq? */
273 static int ip_frag_too_far(struct ipq *qp)
275 struct inet_peer *peer = qp->peer;
276 unsigned int max = qp->q.net->max_dist;
277 unsigned int start, end;
279 int rc;
281 if (!peer || !max)
282 return 0;
284 start = qp->rid;
285 end = atomic_inc_return(&peer->rid);
286 qp->rid = end;
288 rc = qp->q.fragments && (end - start) > max;
290 if (rc) {
291 struct net *net;
293 net = container_of(qp->q.net, struct net, ipv4.frags);
294 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
297 return rc;
300 static int ip_frag_reinit(struct ipq *qp)
302 struct sk_buff *fp;
303 unsigned int sum_truesize = 0;
305 if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
306 atomic_inc(&qp->q.refcnt);
307 return -ETIMEDOUT;
310 fp = qp->q.fragments;
311 do {
312 struct sk_buff *xp = fp->next;
314 sum_truesize += fp->truesize;
315 kfree_skb(fp);
316 fp = xp;
317 } while (fp);
318 sub_frag_mem_limit(qp->q.net, sum_truesize);
320 qp->q.flags = 0;
321 qp->q.len = 0;
322 qp->q.meat = 0;
323 qp->q.fragments = NULL;
324 qp->q.fragments_tail = NULL;
325 qp->iif = 0;
326 qp->ecn = 0;
328 return 0;
331 /* Add new segment to existing queue. */
332 static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
334 struct sk_buff *prev, *next;
335 struct net_device *dev;
336 unsigned int fragsize;
337 int flags, offset;
338 int ihl, end;
339 int err = -ENOENT;
340 u8 ecn;
342 if (qp->q.flags & INET_FRAG_COMPLETE)
343 goto err;
345 if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
346 unlikely(ip_frag_too_far(qp)) &&
347 unlikely(err = ip_frag_reinit(qp))) {
348 ipq_kill(qp);
349 goto err;
352 ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
353 offset = ntohs(ip_hdr(skb)->frag_off);
354 flags = offset & ~IP_OFFSET;
355 offset &= IP_OFFSET;
356 offset <<= 3; /* offset is in 8-byte chunks */
357 ihl = ip_hdrlen(skb);
359 /* Determine the position of this fragment. */
360 end = offset + skb->len - skb_network_offset(skb) - ihl;
361 err = -EINVAL;
363 /* Is this the final fragment? */
364 if ((flags & IP_MF) == 0) {
365 /* If we already have some bits beyond end
366 * or have different end, the segment is corrupted.
368 if (end < qp->q.len ||
369 ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len))
370 goto err;
371 qp->q.flags |= INET_FRAG_LAST_IN;
372 qp->q.len = end;
373 } else {
374 if (end&7) {
375 end &= ~7;
376 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
377 skb->ip_summed = CHECKSUM_NONE;
379 if (end > qp->q.len) {
380 /* Some bits beyond end -> corruption. */
381 if (qp->q.flags & INET_FRAG_LAST_IN)
382 goto err;
383 qp->q.len = end;
386 if (end == offset)
387 goto err;
389 err = -ENOMEM;
390 if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
391 goto err;
393 err = pskb_trim_rcsum(skb, end - offset);
394 if (err)
395 goto err;
397 /* Find out which fragments are in front and at the back of us
398 * in the chain of fragments so far. We must know where to put
399 * this fragment, right?
401 prev = qp->q.fragments_tail;
402 if (!prev || FRAG_CB(prev)->offset < offset) {
403 next = NULL;
404 goto found;
406 prev = NULL;
407 for (next = qp->q.fragments; next != NULL; next = next->next) {
408 if (FRAG_CB(next)->offset >= offset)
409 break; /* bingo! */
410 prev = next;
413 found:
414 /* We found where to put this one. Check for overlap with
415 * preceding fragment, and, if needed, align things so that
416 * any overlaps are eliminated.
418 if (prev) {
419 int i = (FRAG_CB(prev)->offset + prev->len) - offset;
421 if (i > 0) {
422 offset += i;
423 err = -EINVAL;
424 if (end <= offset)
425 goto err;
426 err = -ENOMEM;
427 if (!pskb_pull(skb, i))
428 goto err;
429 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
430 skb->ip_summed = CHECKSUM_NONE;
434 err = -ENOMEM;
436 while (next && FRAG_CB(next)->offset < end) {
437 int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
439 if (i < next->len) {
440 /* Eat head of the next overlapped fragment
441 * and leave the loop. The next ones cannot overlap.
443 if (!pskb_pull(next, i))
444 goto err;
445 FRAG_CB(next)->offset += i;
446 qp->q.meat -= i;
447 if (next->ip_summed != CHECKSUM_UNNECESSARY)
448 next->ip_summed = CHECKSUM_NONE;
449 break;
450 } else {
451 struct sk_buff *free_it = next;
453 /* Old fragment is completely overridden with
454 * new one drop it.
456 next = next->next;
458 if (prev)
459 prev->next = next;
460 else
461 qp->q.fragments = next;
463 qp->q.meat -= free_it->len;
464 sub_frag_mem_limit(qp->q.net, free_it->truesize);
465 kfree_skb(free_it);
469 FRAG_CB(skb)->offset = offset;
471 /* Insert this fragment in the chain of fragments. */
472 skb->next = next;
473 if (!next)
474 qp->q.fragments_tail = skb;
475 if (prev)
476 prev->next = skb;
477 else
478 qp->q.fragments = skb;
480 dev = skb->dev;
481 if (dev) {
482 qp->iif = dev->ifindex;
483 skb->dev = NULL;
485 qp->q.stamp = skb->tstamp;
486 qp->q.meat += skb->len;
487 qp->ecn |= ecn;
488 add_frag_mem_limit(qp->q.net, skb->truesize);
489 if (offset == 0)
490 qp->q.flags |= INET_FRAG_FIRST_IN;
492 fragsize = skb->len + ihl;
494 if (fragsize > qp->q.max_size)
495 qp->q.max_size = fragsize;
497 if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
498 fragsize > qp->max_df_size)
499 qp->max_df_size = fragsize;
501 if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
502 qp->q.meat == qp->q.len) {
503 unsigned long orefdst = skb->_skb_refdst;
505 skb->_skb_refdst = 0UL;
506 err = ip_frag_reasm(qp, prev, dev);
507 skb->_skb_refdst = orefdst;
508 return err;
511 skb_dst_drop(skb);
512 return -EINPROGRESS;
514 err:
515 kfree_skb(skb);
516 return err;
520 /* Build a new IP datagram from all its fragments. */
522 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
523 struct net_device *dev)
525 struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
526 struct iphdr *iph;
527 struct sk_buff *fp, *head = qp->q.fragments;
528 int len;
529 int ihlen;
530 int err;
531 u8 ecn;
533 ipq_kill(qp);
535 ecn = ip_frag_ecn_table[qp->ecn];
536 if (unlikely(ecn == 0xff)) {
537 err = -EINVAL;
538 goto out_fail;
540 /* Make the one we just received the head. */
541 if (prev) {
542 head = prev->next;
543 fp = skb_clone(head, GFP_ATOMIC);
544 if (!fp)
545 goto out_nomem;
547 fp->next = head->next;
548 if (!fp->next)
549 qp->q.fragments_tail = fp;
550 prev->next = fp;
552 skb_morph(head, qp->q.fragments);
553 head->next = qp->q.fragments->next;
555 consume_skb(qp->q.fragments);
556 qp->q.fragments = head;
559 WARN_ON(!head);
560 WARN_ON(FRAG_CB(head)->offset != 0);
562 /* Allocate a new buffer for the datagram. */
563 ihlen = ip_hdrlen(head);
564 len = ihlen + qp->q.len;
566 err = -E2BIG;
567 if (len > 65535)
568 goto out_oversize;
570 /* Head of list must not be cloned. */
571 if (skb_unclone(head, GFP_ATOMIC))
572 goto out_nomem;
574 /* If the first fragment is fragmented itself, we split
575 * it to two chunks: the first with data and paged part
576 * and the second, holding only fragments. */
577 if (skb_has_frag_list(head)) {
578 struct sk_buff *clone;
579 int i, plen = 0;
581 clone = alloc_skb(0, GFP_ATOMIC);
582 if (!clone)
583 goto out_nomem;
584 clone->next = head->next;
585 head->next = clone;
586 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
587 skb_frag_list_init(head);
588 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
589 plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
590 clone->len = clone->data_len = head->data_len - plen;
591 head->data_len -= clone->len;
592 head->len -= clone->len;
593 clone->csum = 0;
594 clone->ip_summed = head->ip_summed;
595 add_frag_mem_limit(qp->q.net, clone->truesize);
598 skb_shinfo(head)->frag_list = head->next;
599 skb_push(head, head->data - skb_network_header(head));
601 for (fp=head->next; fp; fp = fp->next) {
602 head->data_len += fp->len;
603 head->len += fp->len;
604 if (head->ip_summed != fp->ip_summed)
605 head->ip_summed = CHECKSUM_NONE;
606 else if (head->ip_summed == CHECKSUM_COMPLETE)
607 head->csum = csum_add(head->csum, fp->csum);
608 head->truesize += fp->truesize;
610 sub_frag_mem_limit(qp->q.net, head->truesize);
612 head->next = NULL;
613 head->dev = dev;
614 head->tstamp = qp->q.stamp;
615 IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
617 iph = ip_hdr(head);
618 iph->tot_len = htons(len);
619 iph->tos |= ecn;
621 /* When we set IP_DF on a refragmented skb we must also force a
622 * call to ip_fragment to avoid forwarding a DF-skb of size s while
623 * original sender only sent fragments of size f (where f < s).
625 * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest
626 * frag seen to avoid sending tiny DF-fragments in case skb was built
627 * from one very small df-fragment and one large non-df frag.
629 if (qp->max_df_size == qp->q.max_size) {
630 IPCB(head)->flags |= IPSKB_FRAG_PMTU;
631 iph->frag_off = htons(IP_DF);
632 } else {
633 iph->frag_off = 0;
636 ip_send_check(iph);
638 __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
639 qp->q.fragments = NULL;
640 qp->q.fragments_tail = NULL;
641 return 0;
643 out_nomem:
644 net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp);
645 err = -ENOMEM;
646 goto out_fail;
647 out_oversize:
648 net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr);
649 out_fail:
650 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
651 return err;
654 /* Process an incoming IP datagram fragment. */
655 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
657 struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
658 int vif = l3mdev_master_ifindex_rcu(dev);
659 struct ipq *qp;
661 __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
662 skb_orphan(skb);
664 /* Lookup (or create) queue header */
665 qp = ip_find(net, ip_hdr(skb), user, vif);
666 if (qp) {
667 int ret;
669 spin_lock(&qp->q.lock);
671 ret = ip_frag_queue(qp, skb);
673 spin_unlock(&qp->q.lock);
674 ipq_put(qp);
675 return ret;
678 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
679 kfree_skb(skb);
680 return -ENOMEM;
682 EXPORT_SYMBOL(ip_defrag);
684 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
686 struct iphdr iph;
687 int netoff;
688 u32 len;
690 if (skb->protocol != htons(ETH_P_IP))
691 return skb;
693 netoff = skb_network_offset(skb);
695 if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
696 return skb;
698 if (iph.ihl < 5 || iph.version != 4)
699 return skb;
701 len = ntohs(iph.tot_len);
702 if (skb->len < netoff + len || len < (iph.ihl * 4))
703 return skb;
705 if (ip_is_fragment(&iph)) {
706 skb = skb_share_check(skb, GFP_ATOMIC);
707 if (skb) {
708 if (!pskb_may_pull(skb, netoff + iph.ihl * 4))
709 return skb;
710 if (pskb_trim_rcsum(skb, netoff + len))
711 return skb;
712 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
713 if (ip_defrag(net, skb, user))
714 return NULL;
715 skb_clear_hash(skb);
718 return skb;
720 EXPORT_SYMBOL(ip_check_defrag);
722 #ifdef CONFIG_SYSCTL
723 static int zero;
725 static struct ctl_table ip4_frags_ns_ctl_table[] = {
727 .procname = "ipfrag_high_thresh",
728 .data = &init_net.ipv4.frags.high_thresh,
729 .maxlen = sizeof(int),
730 .mode = 0644,
731 .proc_handler = proc_dointvec_minmax,
732 .extra1 = &init_net.ipv4.frags.low_thresh
735 .procname = "ipfrag_low_thresh",
736 .data = &init_net.ipv4.frags.low_thresh,
737 .maxlen = sizeof(int),
738 .mode = 0644,
739 .proc_handler = proc_dointvec_minmax,
740 .extra1 = &zero,
741 .extra2 = &init_net.ipv4.frags.high_thresh
744 .procname = "ipfrag_time",
745 .data = &init_net.ipv4.frags.timeout,
746 .maxlen = sizeof(int),
747 .mode = 0644,
748 .proc_handler = proc_dointvec_jiffies,
751 .procname = "ipfrag_max_dist",
752 .data = &init_net.ipv4.frags.max_dist,
753 .maxlen = sizeof(int),
754 .mode = 0644,
755 .proc_handler = proc_dointvec_minmax,
756 .extra1 = &zero
761 /* secret interval has been deprecated */
762 static int ip4_frags_secret_interval_unused;
763 static struct ctl_table ip4_frags_ctl_table[] = {
765 .procname = "ipfrag_secret_interval",
766 .data = &ip4_frags_secret_interval_unused,
767 .maxlen = sizeof(int),
768 .mode = 0644,
769 .proc_handler = proc_dointvec_jiffies,
774 static int __net_init ip4_frags_ns_ctl_register(struct net *net)
776 struct ctl_table *table;
777 struct ctl_table_header *hdr;
779 table = ip4_frags_ns_ctl_table;
780 if (!net_eq(net, &init_net)) {
781 table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
782 if (!table)
783 goto err_alloc;
785 table[0].data = &net->ipv4.frags.high_thresh;
786 table[0].extra1 = &net->ipv4.frags.low_thresh;
787 table[0].extra2 = &init_net.ipv4.frags.high_thresh;
788 table[1].data = &net->ipv4.frags.low_thresh;
789 table[1].extra2 = &net->ipv4.frags.high_thresh;
790 table[2].data = &net->ipv4.frags.timeout;
791 table[3].data = &net->ipv4.frags.max_dist;
794 hdr = register_net_sysctl(net, "net/ipv4", table);
795 if (!hdr)
796 goto err_reg;
798 net->ipv4.frags_hdr = hdr;
799 return 0;
801 err_reg:
802 if (!net_eq(net, &init_net))
803 kfree(table);
804 err_alloc:
805 return -ENOMEM;
808 static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
810 struct ctl_table *table;
812 table = net->ipv4.frags_hdr->ctl_table_arg;
813 unregister_net_sysctl_table(net->ipv4.frags_hdr);
814 kfree(table);
817 static void __init ip4_frags_ctl_register(void)
819 register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
821 #else
822 static int ip4_frags_ns_ctl_register(struct net *net)
824 return 0;
827 static void ip4_frags_ns_ctl_unregister(struct net *net)
831 static void __init ip4_frags_ctl_register(void)
834 #endif
836 static int __net_init ipv4_frags_init_net(struct net *net)
838 int res;
840 /* Fragment cache limits.
842 * The fragment memory accounting code, (tries to) account for
843 * the real memory usage, by measuring both the size of frag
844 * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
845 * and the SKB's truesize.
847 * A 64K fragment consumes 129736 bytes (44*2944)+200
848 * (1500 truesize == 2944, sizeof(struct ipq) == 200)
850 * We will commit 4MB at one time. Should we cross that limit
851 * we will prune down to 3MB, making room for approx 8 big 64K
852 * fragments 8x128k.
854 net->ipv4.frags.high_thresh = 4 * 1024 * 1024;
855 net->ipv4.frags.low_thresh = 3 * 1024 * 1024;
857 * Important NOTE! Fragment queue must be destroyed before MSL expires.
858 * RFC791 is wrong proposing to prolongate timer each fragment arrival
859 * by TTL.
861 net->ipv4.frags.timeout = IP_FRAG_TIME;
863 net->ipv4.frags.max_dist = 64;
865 res = inet_frags_init_net(&net->ipv4.frags);
866 if (res)
867 return res;
868 res = ip4_frags_ns_ctl_register(net);
869 if (res)
870 inet_frags_uninit_net(&net->ipv4.frags);
871 return res;
874 static void __net_exit ipv4_frags_exit_net(struct net *net)
876 ip4_frags_ns_ctl_unregister(net);
877 inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
880 static struct pernet_operations ip4_frags_ops = {
881 .init = ipv4_frags_init_net,
882 .exit = ipv4_frags_exit_net,
885 void __init ipfrag_init(void)
887 ip4_frags_ctl_register();
888 register_pernet_subsys(&ip4_frags_ops);
889 ip4_frags.hashfn = ip4_hashfn;
890 ip4_frags.constructor = ip4_frag_init;
891 ip4_frags.destructor = ip4_frag_free;
892 ip4_frags.qsize = sizeof(struct ipq);
893 ip4_frags.match = ip4_frag_match;
894 ip4_frags.frag_expire = ip_expire;
895 ip4_frags.frags_cache_name = ip_frag_cache_name;
896 if (inet_frags_init(&ip4_frags))
897 panic("IP: failed to allocate ip4_frags cache\n");