1// SPDX-License-Identifier: GPL-2.0
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * The IP fragmentation functionality.
8 *
9 * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox <alan@lxorguk.ukuu.org.uk>
11 *
12 * Fixes:
13 * Alan Cox : Split from ip.c , see ip_input.c for history.
14 * David S. Miller : Begin massive cleanup...
15 * Andi Kleen : Add sysctls.
16 * xxxx : Overlapfrag bug.
17 * Ultima : ip_expire() kernel panic.
18 * Bill Hawes : Frag accounting and evictor fixes.
19 * John McDonald : 0 length frag bug.
20 * Alexey Kuznetsov: SMP races, threading, cleanup.
21 * Patrick McHardy : LRU queue of frag heads for evictor.
22 */
23
24#define pr_fmt(fmt) "IPv4: " fmt
25
26#include <linux/compiler.h>
27#include <linux/module.h>
28#include <linux/types.h>
29#include <linux/mm.h>
30#include <linux/jiffies.h>
31#include <linux/skbuff.h>
32#include <linux/list.h>
33#include <linux/ip.h>
34#include <linux/icmp.h>
35#include <linux/netdevice.h>
36#include <linux/jhash.h>
37#include <linux/random.h>
38#include <linux/slab.h>
39#include <net/route.h>
40#include <net/dst.h>
41#include <net/sock.h>
42#include <net/ip.h>
43#include <net/icmp.h>
44#include <net/checksum.h>
45#include <net/inetpeer.h>
46#include <net/inet_frag.h>
47#include <linux/tcp.h>
48#include <linux/udp.h>
49#include <linux/inet.h>
50#include <linux/netfilter_ipv4.h>
51#include <net/inet_ecn.h>
52#include <net/l3mdev.h>
53
54/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
55 * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
56 * as well. Or notify me, at least. --ANK
57 */
58static const char ip_frag_cache_name[] = "ip4-frags";
59
60/* Describe an entry in the "incomplete datagrams" queue. */
61struct ipq {
62 struct inet_frag_queue q;
63
64 u8 ecn; /* RFC3168 support */
65 u16 max_df_size; /* largest frag with DF set seen */
66 int iif;
67 unsigned int rid;
68 struct inet_peer *peer;
69};
70
71static u8 ip4_frag_ecn(u8 tos)
72{
73 return 1 << (tos & INET_ECN_MASK);
74}
75
76static struct inet_frags ip4_frags;
77
78static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
79 struct sk_buff *prev_tail, struct net_device *dev);
80
81
82static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
83{
84 struct ipq *qp = container_of(q, struct ipq, q);
85 struct netns_ipv4 *ipv4 = container_of(q->net, struct netns_ipv4,
86 frags);
87 struct net *net = container_of(ipv4, struct net, ipv4);
88
89 const struct frag_v4_compare_key *key = a;
90
91 q->key.v4 = *key;
92 qp->ecn = 0;
93 qp->peer = q->net->max_dist ?
94 inet_getpeer_v4(net->ipv4.peers, key->saddr, key->vif, 1) :
95 NULL;
96}
97
98static void ip4_frag_free(struct inet_frag_queue *q)
99{
100 struct ipq *qp;
101
102 qp = container_of(q, struct ipq, q);
103 if (qp->peer)
104 inet_putpeer(qp->peer);
105}
106
107
108/* Destruction primitives. */
109
110static void ipq_put(struct ipq *ipq)
111{
112 inet_frag_put(&ipq->q);
113}
114
115/* Kill ipq entry. It is not destroyed immediately,
116 * because caller (and someone more) holds reference count.
117 */
118static void ipq_kill(struct ipq *ipq)
119{
120 inet_frag_kill(&ipq->q);
121}
122
123static bool frag_expire_skip_icmp(u32 user)
124{
125 return user == IP_DEFRAG_AF_PACKET ||
126 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN,
127 __IP_DEFRAG_CONNTRACK_IN_END) ||
128 ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN,
129 __IP_DEFRAG_CONNTRACK_BRIDGE_IN);
130}
131
132/*
133 * Oops, a fragment queue timed out. Kill it and send an ICMP reply.
134 */
135static void ip_expire(struct timer_list *t)
136{
137 struct inet_frag_queue *frag = from_timer(frag, t, timer);
138 const struct iphdr *iph;
139 struct sk_buff *head = NULL;
140 struct net *net;
141 struct ipq *qp;
142 int err;
143
144 qp = container_of(frag, struct ipq, q);
145 net = container_of(qp->q.net, struct net, ipv4.frags);
146
147 rcu_read_lock();
148 spin_lock(&qp->q.lock);
149
150 if (qp->q.flags & INET_FRAG_COMPLETE)
151 goto out;
152
153 ipq_kill(qp);
154 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
155 __IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
156
157 if (!(qp->q.flags & INET_FRAG_FIRST_IN))
158 goto out;
159
160 /* sk_buff::dev and sk_buff::rbnode are unionized. So we
161 * pull the head out of the tree in order to be able to
162 * deal with head->dev.
163 */
164 head = inet_frag_pull_head(&qp->q);
165 if (!head)
166 goto out;
167 head->dev = dev_get_by_index_rcu(net, qp->iif);
168 if (!head->dev)
169 goto out;
170
171
172 /* skb has no dst, perform route lookup again */
173 iph = ip_hdr(head);
174 err = ip_route_input_noref(head, iph->daddr, iph->saddr,
175 iph->tos, head->dev);
176 if (err)
177 goto out;
178
179 /* Only an end host needs to send an ICMP
180 * "Fragment Reassembly Timeout" message, per RFC792.
181 */
182 if (frag_expire_skip_icmp(qp->q.key.v4.user) &&
183 (skb_rtable(head)->rt_type != RTN_LOCAL))
184 goto out;
185
186 spin_unlock(&qp->q.lock);
187 icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
188 goto out_rcu_unlock;
189
190out:
191 spin_unlock(&qp->q.lock);
192out_rcu_unlock:
193 rcu_read_unlock();
194 kfree_skb(head);
195 ipq_put(qp);
196}
197
198/* Find the correct entry in the "incomplete datagrams" queue for
199 * this IP datagram, and create new one, if nothing is found.
200 */
201static struct ipq *ip_find(struct net *net, struct iphdr *iph,
202 u32 user, int vif)
203{
204 struct frag_v4_compare_key key = {
205 .saddr = iph->saddr,
206 .daddr = iph->daddr,
207 .user = user,
208 .vif = vif,
209 .id = iph->id,
210 .protocol = iph->protocol,
211 };
212 struct inet_frag_queue *q;
213
214 q = inet_frag_find(&net->ipv4.frags, &key);
215 if (!q)
216 return NULL;
217
218 return container_of(q, struct ipq, q);
219}
220
221/* Is the fragment too far ahead to be part of ipq? */
222static int ip_frag_too_far(struct ipq *qp)
223{
224 struct inet_peer *peer = qp->peer;
225 unsigned int max = qp->q.net->max_dist;
226 unsigned int start, end;
227
228 int rc;
229
230 if (!peer || !max)
231 return 0;
232
233 start = qp->rid;
234 end = atomic_inc_return(&peer->rid);
235 qp->rid = end;
236
237 rc = qp->q.fragments_tail && (end - start) > max;
238
239 if (rc) {
240 struct net *net;
241
242 net = container_of(qp->q.net, struct net, ipv4.frags);
243 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
244 }
245
246 return rc;
247}
248
249static int ip_frag_reinit(struct ipq *qp)
250{
251 unsigned int sum_truesize = 0;
252
253 if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
254 refcount_inc(&qp->q.refcnt);
255 return -ETIMEDOUT;
256 }
257
258 sum_truesize = inet_frag_rbtree_purge(&qp->q.rb_fragments);
259 sub_frag_mem_limit(qp->q.net, sum_truesize);
260
261 qp->q.flags = 0;
262 qp->q.len = 0;
263 qp->q.meat = 0;
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;
269
270 return 0;
271}
272
273/* Add new segment to existing queue. */
274static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
275{
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;
283
284 if (qp->q.flags & INET_FRAG_COMPLETE)
285 goto err;
286
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;
292 }
293
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);
300
301 /* Determine the position of this fragment. */
302 end = offset + skb->len - skb_network_offset(skb) - ihl;
303 err = -EINVAL;
304
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.
309 */
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;
320 }
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;
326 }
327 }
328 if (end == offset)
329 goto discard_qp;
330
331 err = -ENOMEM;
332 if (!pskb_pull(skb, skb_network_offset(skb) + ihl))
333 goto discard_qp;
334
335 err = pskb_trim_rcsum(skb, end - offset);
336 if (err)
337 goto discard_qp;
338
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();
343
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;
348
349 if (dev)
350 qp->iif = dev->ifindex;
351
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;
358
359 fragsize = skb->len + ihl;
360
361 if (fragsize > qp->q.max_size)
362 qp->q.max_size = fragsize;
363
364 if (ip_hdr(skb)->frag_off & htons(IP_DF) &&
365 fragsize > qp->max_df_size)
366 qp->max_df_size = fragsize;
367
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;
371
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;
378 }
379
380 skb_dst_drop(skb);
381 return -EINPROGRESS;
382
383insert_error:
384 if (err == IPFRAG_DUP) {
385 kfree_skb(skb);
386 return -EINVAL;
387 }
388 err = -EINVAL;
389 __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS);
390discard_qp:
391 inet_frag_kill(&qp->q);
392 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
393err:
394 kfree_skb(skb);
395 return err;
396}
397
398/* Build a new IP datagram from all its fragments. */
399static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
400 struct sk_buff *prev_tail, struct net_device *dev)
401{
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;
407
408 ipq_kill(qp);
409
410 ecn = ip_frag_ecn_table[qp->ecn];
411 if (unlikely(ecn == 0xff)) {
412 err = -EINVAL;
413 goto out_fail;
414 }
415
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;
420
421 len = ip_hdrlen(skb) + qp->q.len;
422 err = -E2BIG;
423 if (len > 65535)
424 goto out_oversize;
425
426 inet_frag_reasm_finish(&qp->q, skb, reasm_data);
427
428 skb->dev = dev;
429 IPCB(skb)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
430
431 iph = ip_hdr(skb);
432 iph->tot_len = htons(len);
433 iph->tos |= ecn;
434
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).
438 *
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.
442 */
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;
448 }
449
450 ip_send_check(iph);
451
452 __IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
453 qp->q.rb_fragments = RB_ROOT;
454 qp->q.fragments_tail = NULL;
455 qp->q.last_run_head = NULL;
456 return 0;
457
458out_nomem:
459 net_dbg_ratelimited("queue_glue: no memory for gluing queue %p\n", qp);
460 err = -ENOMEM;
461 goto out_fail;
462out_oversize:
463 net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->q.key.v4.saddr);
464out_fail:
465 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
466 return err;
467}
468
469/* Process an incoming IP datagram fragment. */
470int ip_defrag(struct net *net, struct sk_buff *skb, u32 user)
471{
472 struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
473 int vif = l3mdev_master_ifindex_rcu(dev);
474 struct ipq *qp;
475
476 __IP_INC_STATS(net, IPSTATS_MIB_REASMREQDS);
477 skb_orphan(skb);
478
479 /* Lookup (or create) queue header */
480 qp = ip_find(net, ip_hdr(skb), user, vif);
481 if (qp) {
482 int ret;
483
484 spin_lock(&qp->q.lock);
485
486 ret = ip_frag_queue(qp, skb);
487
488 spin_unlock(&qp->q.lock);
489 ipq_put(qp);
490 return ret;
491 }
492
493 __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
494 kfree_skb(skb);
495 return -ENOMEM;
496}
497EXPORT_SYMBOL(ip_defrag);
498
499struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
500{
501 struct iphdr iph;
502 int netoff;
503 u32 len;
504
505 if (skb->protocol != htons(ETH_P_IP))
506 return skb;
507
508 netoff = skb_network_offset(skb);
509
510 if (skb_copy_bits(skb, netoff, &iph, sizeof(iph)) < 0)
511 return skb;
512
513 if (iph.ihl < 5 || iph.version != 4)
514 return skb;
515
516 len = ntohs(iph.tot_len);
517 if (skb->len < netoff + len || len < (iph.ihl * 4))
518 return skb;
519
520 if (ip_is_fragment(&iph)) {
521 skb = skb_share_check(skb, GFP_ATOMIC);
522 if (skb) {
523 if (!pskb_may_pull(skb, netoff + iph.ihl * 4)) {
524 kfree_skb(skb);
525 return NULL;
526 }
527 if (pskb_trim_rcsum(skb, netoff + len)) {
528 kfree_skb(skb);
529 return NULL;
530 }
531 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
532 if (ip_defrag(net, skb, user))
533 return NULL;
534 skb_clear_hash(skb);
535 }
536 }
537 return skb;
538}
539EXPORT_SYMBOL(ip_check_defrag);
540
541#ifdef CONFIG_SYSCTL
542static int dist_min;
543
544static struct ctl_table ip4_frags_ns_ctl_table[] = {
545 {
546 .procname = "ipfrag_high_thresh",
547 .data = &init_net.ipv4.frags.high_thresh,
548 .maxlen = sizeof(unsigned long),
549 .mode = 0644,
550 .proc_handler = proc_doulongvec_minmax,
551 .extra1 = &init_net.ipv4.frags.low_thresh
552 },
553 {
554 .procname = "ipfrag_low_thresh",
555 .data = &init_net.ipv4.frags.low_thresh,
556 .maxlen = sizeof(unsigned long),
557 .mode = 0644,
558 .proc_handler = proc_doulongvec_minmax,
559 .extra2 = &init_net.ipv4.frags.high_thresh
560 },
561 {
562 .procname = "ipfrag_time",
563 .data = &init_net.ipv4.frags.timeout,
564 .maxlen = sizeof(int),
565 .mode = 0644,
566 .proc_handler = proc_dointvec_jiffies,
567 },
568 {
569 .procname = "ipfrag_max_dist",
570 .data = &init_net.ipv4.frags.max_dist,
571 .maxlen = sizeof(int),
572 .mode = 0644,
573 .proc_handler = proc_dointvec_minmax,
574 .extra1 = &dist_min,
575 },
576 { }
577};
578
579/* secret interval has been deprecated */
580static int ip4_frags_secret_interval_unused;
581static struct ctl_table ip4_frags_ctl_table[] = {
582 {
583 .procname = "ipfrag_secret_interval",
584 .data = &ip4_frags_secret_interval_unused,
585 .maxlen = sizeof(int),
586 .mode = 0644,
587 .proc_handler = proc_dointvec_jiffies,
588 },
589 { }
590};
591
592static int __net_init ip4_frags_ns_ctl_register(struct net *net)
593{
594 struct ctl_table *table;
595 struct ctl_table_header *hdr;
596
597 table = ip4_frags_ns_ctl_table;
598 if (!net_eq(net, &init_net)) {
599 table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
600 if (!table)
601 goto err_alloc;
602
603 table[0].data = &net->ipv4.frags.high_thresh;
604 table[0].extra1 = &net->ipv4.frags.low_thresh;
605 table[1].data = &net->ipv4.frags.low_thresh;
606 table[1].extra2 = &net->ipv4.frags.high_thresh;
607 table[2].data = &net->ipv4.frags.timeout;
608 table[3].data = &net->ipv4.frags.max_dist;
609 }
610
611 hdr = register_net_sysctl(net, "net/ipv4", table);
612 if (!hdr)
613 goto err_reg;
614
615 net->ipv4.frags_hdr = hdr;
616 return 0;
617
618err_reg:
619 if (!net_eq(net, &init_net))
620 kfree(table);
621err_alloc:
622 return -ENOMEM;
623}
624
625static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
626{
627 struct ctl_table *table;
628
629 table = net->ipv4.frags_hdr->ctl_table_arg;
630 unregister_net_sysctl_table(net->ipv4.frags_hdr);
631 kfree(table);
632}
633
634static void __init ip4_frags_ctl_register(void)
635{
636 register_net_sysctl(&init_net, "net/ipv4", ip4_frags_ctl_table);
637}
638#else
639static int ip4_frags_ns_ctl_register(struct net *net)
640{
641 return 0;
642}
643
644static void ip4_frags_ns_ctl_unregister(struct net *net)
645{
646}
647
648static void __init ip4_frags_ctl_register(void)
649{
650}
651#endif
652
653static int __net_init ipv4_frags_init_net(struct net *net)
654{
655 int res;
656
657 /* Fragment cache limits.
658 *
659 * The fragment memory accounting code, (tries to) account for
660 * the real memory usage, by measuring both the size of frag
661 * queue struct (inet_frag_queue (ipv4:ipq/ipv6:frag_queue))
662 * and the SKB's truesize.
663 *
664 * A 64K fragment consumes 129736 bytes (44*2944)+200
665 * (1500 truesize == 2944, sizeof(struct ipq) == 200)
666 *
667 * We will commit 4MB at one time. Should we cross that limit
668 * we will prune down to 3MB, making room for approx 8 big 64K
669 * fragments 8x128k.
670 */
671 net->ipv4.frags.high_thresh = 4 * 1024 * 1024;
672 net->ipv4.frags.low_thresh = 3 * 1024 * 1024;
673 /*
674 * Important NOTE! Fragment queue must be destroyed before MSL expires.
675 * RFC791 is wrong proposing to prolongate timer each fragment arrival
676 * by TTL.
677 */
678 net->ipv4.frags.timeout = IP_FRAG_TIME;
679
680 net->ipv4.frags.max_dist = 64;
681 net->ipv4.frags.f = &ip4_frags;
682
683 res = inet_frags_init_net(&net->ipv4.frags);
684 if (res < 0)
685 return res;
686 res = ip4_frags_ns_ctl_register(net);
687 if (res < 0)
688 inet_frags_exit_net(&net->ipv4.frags);
689 return res;
690}
691
692static void __net_exit ipv4_frags_exit_net(struct net *net)
693{
694 ip4_frags_ns_ctl_unregister(net);
695 inet_frags_exit_net(&net->ipv4.frags);
696}
697
698static struct pernet_operations ip4_frags_ops = {
699 .init = ipv4_frags_init_net,
700 .exit = ipv4_frags_exit_net,
701};
702
703
704static u32 ip4_key_hashfn(const void *data, u32 len, u32 seed)
705{
706 return jhash2(data,
707 sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
708}
709
710static u32 ip4_obj_hashfn(const void *data, u32 len, u32 seed)
711{
712 const struct inet_frag_queue *fq = data;
713
714 return jhash2((const u32 *)&fq->key.v4,
715 sizeof(struct frag_v4_compare_key) / sizeof(u32), seed);
716}
717
718static int ip4_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
719{
720 const struct frag_v4_compare_key *key = arg->key;
721 const struct inet_frag_queue *fq = ptr;
722
723 return !!memcmp(&fq->key, key, sizeof(*key));
724}
725
726static const struct rhashtable_params ip4_rhash_params = {
727 .head_offset = offsetof(struct inet_frag_queue, node),
728 .key_offset = offsetof(struct inet_frag_queue, key),
729 .key_len = sizeof(struct frag_v4_compare_key),
730 .hashfn = ip4_key_hashfn,
731 .obj_hashfn = ip4_obj_hashfn,
732 .obj_cmpfn = ip4_obj_cmpfn,
733 .automatic_shrinking = true,
734};
735
736void __init ipfrag_init(void)
737{
738 ip4_frags.constructor = ip4_frag_init;
739 ip4_frags.destructor = ip4_frag_free;
740 ip4_frags.qsize = sizeof(struct ipq);
741 ip4_frags.frag_expire = ip_expire;
742 ip4_frags.frags_cache_name = ip_frag_cache_name;
743 ip4_frags.rhash_params = ip4_rhash_params;
744 if (inet_frags_init(&ip4_frags))
745 panic("IP: failed to allocate ip4_frags cache\n");
746 ip4_frags_ctl_register();
747 register_pernet_subsys(&ip4_frags_ops);
748}
749