dmaengine: ste_dma40: fix unneeded variable warning
[linux/fpc-iii.git] / net / ipv4 / ip_fragment.c
blob6e9ba9dfb5b2c227c73ff539db6bf9196a0859ec
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 /* Describe an entry in the "incomplete datagrams" queue. */
60 struct ipq {
61 struct inet_frag_queue q;
63 u8 ecn; /* RFC3168 support */
64 u16 max_df_size; /* largest frag with DF set seen */
65 int iif;
66 unsigned int rid;
67 struct inet_peer *peer;
70 static u8 ip4_frag_ecn(u8 tos)
72 return 1 << (tos & INET_ECN_MASK);
75 static struct inet_frags ip4_frags;
77 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
78 struct sk_buff *prev_tail, struct net_device *dev);
81 static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
83 struct ipq *qp = container_of(q, struct ipq, q);
84 struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4,
85 frags);
86 struct net *net = container_of(ipv4, struct net, ipv4);
88 const struct frag_v4_compare_key *key = a;
90 q->key.v4 = *key;
91 qp->ecn = 0;
92 qp->peer = q->net->max_dist ?
93 inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) :
94 NULL;
97 static void ip4_frag_free(struct inet_frag_queue *q)
99 struct ipq *qp;
101 qp = container_of(q, struct ipq, q);
102 if (qp->peer)
103 inet_putpeer(qp->peer);
107 /* Destruction primitives. */
109 static void ipq_put(struct ipq *ipq)
111 inet_frag_put(&ipq->q);
114 /* Kill ipq entry. It is not destroyed immediately,
115 * because caller (and someone more) holds reference count.
117 static void ipq_kill(struct ipq *ipq)
119 inet_frag_kill(&ipq->q);
122 static bool frag_expire_skip_icmp(u32 user)
124 return user == IP_DEFRAG_AF_PACKET ||
125 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
126 __IP_DEFRAG_CONNTRACK_IN_END) ||
127 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
128 __IP_DEFRAG_CONNTRACK_BRIDGE_IN);
132 * Oops, a fragment queue timed out. Kill it and send an ICMP reply.
134 static void ip_expire(unsigned long arg)
136 const struct iphdr *iph;
137 struct sk_buff *head = NULL;
138 struct net *net;
139 struct ipq *qp;
140 int err;
142 qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
143 net = container_of(qp->q.net, struct net, ipv4.frags);
145 rcu_read_lock();
146 spin_lock(&qp->q.lock);
148 if (qp->q.flags & INET_FRAG_COMPLETE)
149 goto out;
151 ipq_kill(qp);
152 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
153 __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
155 if (!(qp->q.flags & INET_FRAG_FIRST_IN))
156 goto out;
158 /* sk_buff::dev and sk_buff::rbnode are unionized. So we
159 * pull the head out of the tree in order to be able to
160 * deal with head->dev.
162 head = inet_frag_pull_head(&qp->q);
163 if (!head)
164 goto out;
165 head->dev = dev_get_by_index_rcu(net, qp->iif);
166 if (!head->dev)
167 goto out;
170 /* skb has no dst, perform route lookup again */
171 iph = ip_hdr(head);
172 err = ip_route_input_noref(head, iph->daddr, iph->saddr,
173 iph->tos, head->dev);
174 if (err)
175 goto out;
177 /* Only an end host needs to send an ICMP
178 * "Fragment Reassembly Timeout" message, per RFC792.
180 if (frag_expire_skip_icmp(qp->q.key.v4.user) &&
181 (skb_rtable(head)->rt_type != RTN_LOCAL))
182 goto out;
184 spin_unlock(&qp->q.lock);
185 icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
186 goto out_rcu_unlock;
188 out:
189 spin_unlock(&qp->q.lock);
190 out_rcu_unlock:
191 rcu_read_unlock();
192 if (head)
193 kfree_skb(head);
194 ipq_put(qp);
197 /* Find the correct entry in the "incomplete datagrams" queue for
198 * this IP datagram, and create new one, if nothing is found.
200 static struct ipq *ip_find(struct net *net, struct iphdr *iph,
201 u32 user, int vif)
203 struct frag_v4_compare_key key = {
204 .saddr = iph->saddr,
205 .daddr = iph->daddr,
206 .user = user,
207 .vif = vif,
208 .id = iph->id,
209 .protocol = iph->protocol,
211 struct inet_frag_queue *q;
213 q = inet_frag_find(&net->ipv4.frags, &key);
214 if (!q)
215 return NULL;
217 return container_of(q, struct ipq, q);
220 /* Is the fragment too far ahead to be part of ipq? */
221 static int ip_frag_too_far(struct ipq *qp)
223 struct inet_peer *peer = qp->peer;
224 unsigned int max = qp->q.net->max_dist;
225 unsigned int start, end;
227 int rc;
229 if (!peer || !max)
230 return 0;
232 start = qp->rid;
233 end = atomic_inc_return(&peer->rid);
234 qp->rid = end;
236 rc = qp->q.fragments_tail && (end - start) > max;
238 if (rc) {
239 struct net *net;
241 net = container_of(qp->q.net, struct net, ipv4.frags);
242 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
245 return rc;
248 static int ip_frag_reinit(struct ipq *qp)
250 unsigned int sum_truesize = 0;
252 if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
253 atomic_inc(&qp->q.refcnt);
254 return -ETIMEDOUT;
257 sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);
258 sub_frag_mem_limit(qp->q.net, sum_truesize);
260 qp->q.flags = 0;
261 qp->q.len = 0;
262 qp->q.meat = 0;
263 qp->q.fragments = NULL;
264 qp->q.rb_fragments = RB_ROOT;
265 qp->q.fragments_tail = NULL;
266 qp->q.last_run_head = NULL;
267 qp->iif = 0;
268 qp->ecn = 0;
270 return 0;
273 /* Add new segment to existing queue. */
274 static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
276 struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
277 int ihl, end, flags, offset;
278 struct sk_buff *prev_tail;
279 struct net_device *dev;
280 unsigned int fragsize;
281 int err = -ENOENT;
282 u8 ecn;
284 if (qp->q.flags & INET_FRAG_COMPLETE)
285 goto err;
287 if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
288 unlikely(ip_frag_too_far(qp)) &&
289 unlikely(err = ip_frag_reinit(qp))) {
290 ipq_kill(qp);
291 goto err;
294 ecn = ip4_frag_ecn(ip_hdr(skb)->tos);
295 offset = ntohs(ip_hdr(skb)->frag_off);
296 flags = offset & ~IP_OFFSET;
297 offset &= IP_OFFSET;
298 offset <<= 3; /* offset is in 8-byte chunks */
299 ihl = ip_hdrlen(skb);
301 /* Determine the position of this fragment. */
302 end = offset + skb->len - skb_network_offset(skb) - ihl;
303 err = -EINVAL;
305 /* Is this the final fragment? */
306 if ((flags & IP_MF) == 0) {
307 /* If we already have some bits beyond end
308 * or have different end, the segment is corrupted.
310 if (end < qp->q.len ||
311 ((qp->q.flags & INET_FRAG_LAST_IN) && end != qp->q.len))
312 goto discard_qp;
313 qp->q.flags |= INET_FRAG_LAST_IN;
314 qp->q.len = end;
315 } else {
316 if (end&7) {
317 end &= ~7;
318 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
319 skb->ip_summed = CHECKSUM_NONE;
321 if (end > qp->q.len) {
322 /* Some bits beyond end -> corruption. */
323 if (qp->q.flags & INET_FRAG_LAST_IN)
324 goto discard_qp;
325 qp->q.len = end;
328 if (end == offset)
329 goto discard_qp;
331 err = -ENOMEM;
332 if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
333 goto discard_qp;
335 err = pskb_trim_rcsum(skb, end - offset);
336 if (err)
337 goto discard_qp;
339 /* Note : skb->rbnode and skb->dev share the same location. */
340 dev = skb->dev;
341 /* Makes sure compiler wont do silly aliasing games */
342 barrier();
344 prev_tail = qp->q.fragments_tail;
345 err = inet_frag_queue_insert(&qp->q, skb, offset, end);
346 if (err)
347 goto insert_error;
349 if (dev)
350 qp->iif = dev->ifindex;
352 qp->q.stamp = skb->tstamp;
353 qp->q.meat += skb->len;
354 qp->ecn |= ecn;
355 add_frag_mem_limit(qp->q.net, skb->truesize);
356 if (offset == 0)
357 qp->q.flags |= INET_FRAG_FIRST_IN;
359 fragsize = skb->len + ihl;
361 if (fragsize > qp->q.max_size)
362 qp->q.max_size = fragsize;
364 if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
365 fragsize > qp->max_df_size)
366 qp->max_df_size = fragsize;
368 if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
369 qp->q.meat == qp->q.len) {
370 unsigned long orefdst = skb->_skb_refdst;
372 skb->_skb_refdst = 0UL;
373 err = ip_frag_reasm(qp, skb, prev_tail, dev);
374 skb->_skb_refdst = orefdst;
375 if (err)
376 inet_frag_kill(&qp->q);
377 return err;
380 skb_dst_drop(skb);
381 return -EINPROGRESS;
383 insert_error:
384 if (err == IPFRAG_DUP) {
385 kfree_skb(skb);
386 return -EINVAL;
388 err = -EINVAL;
389 __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
390 discard_qp:
391 inet_frag_kill(&qp->q);
392 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
393 err:
394 kfree_skb(skb);
395 return err;
398 /* Build a new IP datagram from all its fragments. */
399 static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
400 struct sk_buff *prev_tail, struct net_device *dev)
402 struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
403 struct iphdr *iph;
404 void *reasm_data;
405 int len, err;
406 u8 ecn;
408 ipq_kill(qp);
410 ecn = ip_frag_ecn_table[qp->ecn];
411 if (unlikely(ecn == 0xff)) {
412 err = -EINVAL;
413 goto out_fail;
416 /* Make the one we just received the head. */
417 reasm_data = inet_frag_reasm_prepare(&qp->q, skb, prev_tail);
418 if (!reasm_data)
419 goto out_nomem;
421 len = ip_hdrlen(skb) + qp->q.len;
422 err = -E2BIG;
423 if (len > 65535)
424 goto out_oversize;
426 inet_frag_reasm_finish(&qp->q, skb, reasm_data);
428 skb->dev = dev;
429 IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
431 iph = ip_hdr(skb);
432 iph->tot_len = htons(len);
433 iph->tos |= ecn;
435 /* When we set IP_DF on a refragmented skb we must also force a
436 * call to ip_fragment to avoid forwarding a DF-skb of size s while
437 * original sender only sent fragments of size f (where f < s).
439 * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest
440 * frag seen to avoid sending tiny DF-fragments in case skb was built
441 * from one very small df-fragment and one large non-df frag.
443 if (qp->max_df_size == qp->q.max_size) {
444 IPCB(skb)->flags |= IPSKB_FRAG_PMTU;
445 iph->frag_off = htons(IP_DF);
446 } else {
447 iph->frag_off = 0;
450 ip_send_check(iph);
452 __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
453 qp->q.fragments = NULL;
454 qp->q.rb_fragments = RB_ROOT;
455 qp->q.fragments_tail = NULL;
456 qp->q.last_run_head = NULL;
457 return 0;
459 out_nomem:
460 net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp);
461 err = -ENOMEM;
462 goto out_fail;
463 out_oversize:
464 net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr);
465 out_fail:
466 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
467 return err;
470 /* Process an incoming IP datagram fragment. */
471 int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
473 struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
474 int vif = l3mdev_master_ifindex_rcu(dev);
475 struct ipq *qp;
477 __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
478 skb_orphan(skb);
480 /* Lookup (or create) queue header */
481 qp = ip_find(net, ip_hdr(skb), user, vif);
482 if (qp) {
483 int ret;
485 spin_lock(&qp->q.lock);
487 ret = ip_frag_queue(qp, skb);
489 spin_unlock(&qp->q.lock);
490 ipq_put(qp);
491 return ret;
494 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
495 kfree_skb(skb);
496 return -ENOMEM;
498 EXPORT_SYMBOL(ip_defrag);
500 struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
502 struct iphdr iph;
503 int netoff;
504 u32 len;
506 if (skb->protocol != htons(ETH_P_IP))
507 return skb;
509 netoff = skb_network_offset(skb);
511 if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
512 return skb;
514 if (iph.ihl < 5 || iph.version != 4)
515 return skb;
517 len = ntohs(iph.tot_len);
518 if (skb->len < netoff + len || len < (iph.ihl * 4))
519 return skb;
521 if (ip_is_fragment(&iph)) {
522 skb = skb_share_check(skb, GFP_ATOMIC);
523 if (skb) {
524 if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) {
525 kfree_skb(skb);
526 return NULL;
528 if (pskb_trim_rcsum(skb, netoff + len)) {
529 kfree_skb(skb);
530 return NULL;
532 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
533 if (ip_defrag(net, skb, user))
534 return NULL;
535 skb_clear_hash(skb);
538 return skb;
540 EXPORT_SYMBOL(ip_check_defrag);
542 #ifdef CONFIG_SYSCTL
543 static int dist_min;
545 static struct ctl_table ip4_frags_ns_ctl_table[] = {
547 .procname = "ipfrag_high_thresh",
548 .data = &init_net.ipv4.frags.high_thresh,
549 .maxlen = sizeof(unsigned long),
550 .mode = 0644,
551 .proc_handler = proc_doulongvec_minmax,
552 .extra1 = &init_net.ipv4.frags.low_thresh
555 .procname = "ipfrag_low_thresh",
556 .data = &init_net.ipv4.frags.low_thresh,
557 .maxlen = sizeof(unsigned long),
558 .mode = 0644,
559 .proc_handler = proc_doulongvec_minmax,
560 .extra2 = &init_net.ipv4.frags.high_thresh
563 .procname = "ipfrag_time",
564 .data = &init_net.ipv4.frags.timeout,
565 .maxlen = sizeof(int),
566 .mode = 0644,
567 .proc_handler = proc_dointvec_jiffies,
570 .procname = "ipfrag_max_dist",
571 .data = &init_net.ipv4.frags.max_dist,
572 .maxlen = sizeof(int),
573 .mode = 0644,
574 .proc_handler = proc_dointvec_minmax,
575 .extra1 = &dist_min,
580 /* secret interval has been deprecated */
581 static int ip4_frags_secret_interval_unused;
582 static struct ctl_table ip4_frags_ctl_table[] = {
584 .procname = "ipfrag_secret_interval",
585 .data = &ip4_frags_secret_interval_unused,
586 .maxlen = sizeof(int),
587 .mode = 0644,
588 .proc_handler = proc_dointvec_jiffies,
593 static int __net_init ip4_frags_ns_ctl_register(struct net *net)
595 struct ctl_table *table;
596 struct ctl_table_header *hdr;
598 table = ip4_frags_ns_ctl_table;
599 if (!net_eq(net, &init_net)) {
600 table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
601 if (!table)
602 goto err_alloc;
604 table[0].data = &net->ipv4.frags.high_thresh;
605 table[0].extra1 = &net->ipv4.frags.low_thresh;
606 table[0].extra2 = &init_net.ipv4.frags.high_thresh;
607 table[1].data = &net->ipv4.frags.low_thresh;
608 table[1].extra2 = &net->ipv4.frags.high_thresh;
609 table[2].data = &net->ipv4.frags.timeout;
610 table[3].data = &net->ipv4.frags.max_dist;
613 hdr = register_net_sysctl(net, "net/ipv4", table);
614 if (!hdr)
615 goto err_reg;
617 net->ipv4.frags_hdr = hdr;
618 return 0;
620 err_reg:
621 if (!net_eq(net, &init_net))
622 kfree(table);
623 err_alloc:
624 return -ENOMEM;
627 static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
629 struct ctl_table *table;
631 table = net->ipv4.frags_hdr->ctl_table_arg;
632 unregister_net_sysctl_table(net->ipv4.frags_hdr);
633 kfree(table);
636 static void __init ip4_frags_ctl_register(void)
638 register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
640 #else
641 static int ip4_frags_ns_ctl_register(struct net *net)
643 return 0;
646 static void ip4_frags_ns_ctl_unregister(struct net *net)
650 static void __init ip4_frags_ctl_register(void)
653 #endif
655 static int __net_init ipv4_frags_init_net(struct net *net)
657 int res;
659 /* Fragment cache limits.
661 * The fragment memory accounting code, (tries to) account for
662 * the real memory usage, by measuring both the size of frag
663 * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
664 * and the SKB's truesize.
666 * A 64K fragment consumes 129736 bytes (44*2944)+200
667 * (1500 truesize == 2944, sizeof(struct ipq) == 200)
669 * We will commit 4MB at one time. Should we cross that limit
670 * we will prune down to 3MB, making room for approx 8 big 64K
671 * fragments 8x128k.
673 net->ipv4.frags.high_thresh = 4 * 1024 * 1024;
674 net->ipv4.frags.low_thresh = 3 * 1024 * 1024;
676 * Important NOTE! Fragment queue must be destroyed before MSL expires.
677 * RFC791 is wrong proposing to prolongate timer each fragment arrival
678 * by TTL.
680 net->ipv4.frags.timeout = IP_FRAG_TIME;
682 net->ipv4.frags.max_dist = 64;
683 net->ipv4.frags.f = &ip4_frags;
685 res = inet_frags_init_net(&net->ipv4.frags);
686 if (res < 0)
687 return res;
688 res = ip4_frags_ns_ctl_register(net);
689 if (res < 0)
690 inet_frags_exit_net(&net->ipv4.frags);
691 return res;
694 static void __net_exit ipv4_frags_exit_net(struct net *net)
696 ip4_frags_ns_ctl_unregister(net);
697 inet_frags_exit_net(&net->ipv4.frags);
700 static struct pernet_operations ip4_frags_ops = {
701 .init = ipv4_frags_init_net,
702 .exit = ipv4_frags_exit_net,
706 static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed)
708 return jhash2(data,
709 sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
712 static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed)
714 const struct inet_frag_queue *fq = data;
716 return jhash2((const u32 *)&fq->key.v4,
717 sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
720 static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
722 const struct frag_v4_compare_key *key = arg->key;
723 const struct inet_frag_queue *fq = ptr;
725 return !!memcmp(&fq->key, key, sizeof(*key));
728 static const struct rhashtable_params ip4_rhash_params = {
729 .head_offset = offsetof(struct inet_frag_queue, node),
730 .key_offset = offsetof(struct inet_frag_queue, key),
731 .key_len = sizeof(struct frag_v4_compare_key),
732 .hashfn = ip4_key_hashfn,
733 .obj_hashfn = ip4_obj_hashfn,
734 .obj_cmpfn = ip4_obj_cmpfn,
735 .automatic_shrinking = true,
738 void __init ipfrag_init(void)
740 ip4_frags.constructor = ip4_frag_init;
741 ip4_frags.destructor = ip4_frag_free;
742 ip4_frags.qsize = sizeof(struct ipq);
743 ip4_frags.frag_expire = ip_expire;
744 ip4_frags.frags_cache_name = ip_frag_cache_name;
745 ip4_frags.rhash_params = ip4_rhash_params;
746 if (inet_frags_init(&ip4_frags))
747 panic("IP: failed to allocate ip4_frags cache\n");
748 ip4_frags_ctl_register();
749 register_pernet_subsys(&ip4_frags_ops);