blob: 168440834adedd4935b05229b533c6dad9b16e81 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
5 *
6 * The IP fragmentation functionality.
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09007 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Authors: Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
Alan Cox113aa832008-10-13 19:01:08 -07009 * Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
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.
21 */
22
Herbert Xu89cee8b2005-12-13 23:14:27 -080023#include <linux/compiler.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25#include <linux/types.h>
26#include <linux/mm.h>
27#include <linux/jiffies.h>
28#include <linux/skbuff.h>
29#include <linux/list.h>
30#include <linux/ip.h>
31#include <linux/icmp.h>
32#include <linux/netdevice.h>
33#include <linux/jhash.h>
34#include <linux/random.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Shan Weie9017b52010-01-23 01:57:42 -080036#include <net/route.h>
37#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <net/sock.h>
39#include <net/ip.h>
40#include <net/icmp.h>
41#include <net/checksum.h>
Herbert Xu89cee8b2005-12-13 23:14:27 -080042#include <net/inetpeer.h>
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -070043#include <net/inet_frag.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/tcp.h>
45#include <linux/udp.h>
46#include <linux/inet.h>
47#include <linux/netfilter_ipv4.h>
48
49/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
50 * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
51 * as well. Or notify me, at least. --ANK
52 */
53
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -080054static int sysctl_ipfrag_max_dist __read_mostly = 64;
Herbert Xu89cee8b2005-12-13 23:14:27 -080055
Linus Torvalds1da177e2005-04-16 15:20:36 -070056struct ipfrag_skb_cb
57{
58 struct inet_skb_parm h;
59 int offset;
60};
61
Jianjun Kongfd3f8c42008-11-03 02:47:38 -080062#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64/* Describe an entry in the "incomplete datagrams" queue. */
65struct ipq {
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -070066 struct inet_frag_queue q;
67
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 u32 user;
Al Viro18277772006-09-26 22:19:02 -070069 __be32 saddr;
70 __be32 daddr;
71 __be16 id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 u8 protocol;
Herbert Xu89cee8b2005-12-13 23:14:27 -080073 int iif;
74 unsigned int rid;
75 struct inet_peer *peer;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076};
77
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070078static struct inet_frags ip4_frags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Pavel Emelyanove5a2bb82008-01-22 06:06:23 -080080int ip_frag_nqueues(struct net *net)
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070081{
Pavel Emelyanove5a2bb82008-01-22 06:06:23 -080082 return net->ipv4.frags.nqueues;
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070083}
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -080085int ip_frag_mem(struct net *net)
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070086{
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -080087 return atomic_read(&net->ipv4.frags.mem);
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070088}
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Herbert Xu1706d582007-10-14 00:38:15 -070090static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
91 struct net_device *dev);
92
Pavel Emelyanovc6fda282007-10-17 19:46:47 -070093struct ip4_create_arg {
94 struct iphdr *iph;
95 u32 user;
96};
97
Al Viro18277772006-09-26 22:19:02 -070098static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
Linus Torvalds1da177e2005-04-16 15:20:36 -070099{
Al Viro18277772006-09-26 22:19:02 -0700100 return jhash_3words((__force u32)id << 16 | prot,
101 (__force u32)saddr, (__force u32)daddr,
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700102 ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700105static unsigned int ip4_hashfn(struct inet_frag_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700107 struct ipq *ipq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700109 ipq = container_of(q, struct ipq, q);
110 return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700113static int ip4_frag_match(struct inet_frag_queue *q, void *a)
114{
115 struct ipq *qp;
116 struct ip4_create_arg *arg = a;
117
118 qp = container_of(q, struct ipq, q);
Eric Dumazeta02cec22010-09-22 20:43:57 +0000119 return qp->id == arg->iph->id &&
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700120 qp->saddr == arg->iph->saddr &&
121 qp->daddr == arg->iph->daddr &&
122 qp->protocol == arg->iph->protocol &&
Eric Dumazeta02cec22010-09-22 20:43:57 +0000123 qp->user == arg->user;
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700124}
125
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126/* Memory Tracking Functions. */
Eric Dumazeta95d8c82010-06-13 23:22:43 +0000127static void frag_kfree_skb(struct netns_frags *nf, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128{
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800129 atomic_sub(skb->truesize, &nf->mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 kfree_skb(skb);
131}
132
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700133static void ip4_frag_init(struct inet_frag_queue *q, void *a)
134{
135 struct ipq *qp = container_of(q, struct ipq, q);
136 struct ip4_create_arg *arg = a;
137
138 qp->protocol = arg->iph->protocol;
139 qp->id = arg->iph->id;
140 qp->saddr = arg->iph->saddr;
141 qp->daddr = arg->iph->daddr;
142 qp->user = arg->user;
143 qp->peer = sysctl_ipfrag_max_dist ?
144 inet_getpeer(arg->iph->saddr, 1) : NULL;
145}
146
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700147static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700149 struct ipq *qp;
150
151 qp = container_of(q, struct ipq, q);
152 if (qp->peer)
153 inet_putpeer(qp->peer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157/* Destruction primitives. */
158
Pavel Emelyanov4b6cb5d2007-10-15 02:41:09 -0700159static __inline__ void ipq_put(struct ipq *ipq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
Pavel Emelyanov762cc402007-10-15 02:41:56 -0700161 inet_frag_put(&ipq->q, &ip4_frags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162}
163
164/* Kill ipq entry. It is not destroyed immediately,
165 * because caller (and someone more) holds reference count.
166 */
167static void ipq_kill(struct ipq *ipq)
168{
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700169 inet_frag_kill(&ipq->q, &ip4_frags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170}
171
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900172/* Memory limiting on fragments. Evictor trashes the oldest
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 * fragment queue until we are back under the threshold.
174 */
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800175static void ip_evictor(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176{
Pavel Emelyanov8e7999c2007-10-15 02:40:06 -0700177 int evicted;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800179 evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags);
Pavel Emelyanov8e7999c2007-10-15 02:40:06 -0700180 if (evicted)
Pavel Emelyanovc5346fe2008-07-16 20:20:33 -0700181 IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182}
183
184/*
185 * Oops, a fragment queue timed out. Kill it and send an ICMP reply.
186 */
187static void ip_expire(unsigned long arg)
188{
Pavel Emelyanove521db92007-10-17 19:45:23 -0700189 struct ipq *qp;
Pavel Emelyanov84a3aa02008-07-16 20:19:08 -0700190 struct net *net;
Pavel Emelyanove521db92007-10-17 19:45:23 -0700191
192 qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
Pavel Emelyanov84a3aa02008-07-16 20:19:08 -0700193 net = container_of(qp->q.net, struct net, ipv4.frags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700195 spin_lock(&qp->q.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Joe Perchesbc578a52008-03-28 16:35:27 -0700197 if (qp->q.last_in & INET_FRAG_COMPLETE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 goto out;
199
200 ipq_kill(qp);
201
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700202 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);
203 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
Joe Perchesbc578a52008-03-28 16:35:27 -0700205 if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700206 struct sk_buff *head = qp->q.fragments;
Denis V. Lunevcb846632008-03-24 15:31:00 -0700207
Eric Dumazet69df9d52009-11-05 20:59:47 -0800208 rcu_read_lock();
209 head->dev = dev_get_by_index_rcu(net, qp->iif);
Shan Weie9017b52010-01-23 01:57:42 -0800210 if (!head->dev)
211 goto out_rcu_unlock;
212
213 /*
214 * Only search router table for the head fragment,
215 * when defraging timeout at PRE_ROUTING HOOK.
216 */
217 if (qp->user == IP_DEFRAG_CONNTRACK_IN && !skb_dst(head)) {
218 const struct iphdr *iph = ip_hdr(head);
219 int err = ip_route_input(head, iph->daddr, iph->saddr,
220 iph->tos, head->dev);
221 if (unlikely(err))
222 goto out_rcu_unlock;
223
224 /*
225 * Only an end host needs to send an ICMP
226 * "Fragment Reassembly Timeout" message, per RFC792.
227 */
228 if (skb_rtable(head)->rt_type != RTN_LOCAL)
229 goto out_rcu_unlock;
230
231 }
232
233 /* Send an ICMP "Fragment Reassembly Timeout" message. */
234 icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
Shan Weie9017b52010-01-23 01:57:42 -0800235out_rcu_unlock:
Patrick McHardyd1c9ae62010-02-02 11:46:50 -0800236 rcu_read_unlock();
237 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238out:
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700239 spin_unlock(&qp->q.lock);
Pavel Emelyanov4b6cb5d2007-10-15 02:41:09 -0700240 ipq_put(qp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241}
242
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700243/* Find the correct entry in the "incomplete datagrams" queue for
244 * this IP datagram, and create new one, if nothing is found.
245 */
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800246static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700248 struct inet_frag_queue *q;
249 struct ip4_create_arg arg;
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700250 unsigned int hash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700252 arg.iph = iph;
253 arg.user = user;
Pavel Emelyanov9a375802008-06-27 20:06:08 -0700254
255 read_lock(&ip4_frags.lock);
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700256 hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700257
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800258 q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700259 if (q == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 goto out_nomem;
261
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700262 return container_of(q, struct ipq, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264out_nomem:
Patrick McHardy64ce2072005-08-09 20:50:53 -0700265 LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 return NULL;
267}
268
Herbert Xu89cee8b2005-12-13 23:14:27 -0800269/* Is the fragment too far ahead to be part of ipq? */
270static inline int ip_frag_too_far(struct ipq *qp)
271{
272 struct inet_peer *peer = qp->peer;
273 unsigned int max = sysctl_ipfrag_max_dist;
274 unsigned int start, end;
275
276 int rc;
277
278 if (!peer || !max)
279 return 0;
280
281 start = qp->rid;
282 end = atomic_inc_return(&peer->rid);
283 qp->rid = end;
284
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700285 rc = qp->q.fragments && (end - start) > max;
Herbert Xu89cee8b2005-12-13 23:14:27 -0800286
287 if (rc) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700288 struct net *net;
289
290 net = container_of(qp->q.net, struct net, ipv4.frags);
291 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
Herbert Xu89cee8b2005-12-13 23:14:27 -0800292 }
293
294 return rc;
295}
296
297static int ip_frag_reinit(struct ipq *qp)
298{
299 struct sk_buff *fp;
300
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800301 if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700302 atomic_inc(&qp->q.refcnt);
Herbert Xu89cee8b2005-12-13 23:14:27 -0800303 return -ETIMEDOUT;
304 }
305
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700306 fp = qp->q.fragments;
Herbert Xu89cee8b2005-12-13 23:14:27 -0800307 do {
308 struct sk_buff *xp = fp->next;
Eric Dumazeta95d8c82010-06-13 23:22:43 +0000309 frag_kfree_skb(qp->q.net, fp);
Herbert Xu89cee8b2005-12-13 23:14:27 -0800310 fp = xp;
311 } while (fp);
312
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700313 qp->q.last_in = 0;
314 qp->q.len = 0;
315 qp->q.meat = 0;
316 qp->q.fragments = NULL;
Changli Gaod6bebca2010-06-29 04:39:37 +0000317 qp->q.fragments_tail = NULL;
Herbert Xu89cee8b2005-12-13 23:14:27 -0800318 qp->iif = 0;
319
320 return 0;
321}
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323/* Add new segment to existing queue. */
Herbert Xu1706d582007-10-14 00:38:15 -0700324static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
326 struct sk_buff *prev, *next;
Herbert Xu1706d582007-10-14 00:38:15 -0700327 struct net_device *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 int flags, offset;
329 int ihl, end;
Herbert Xu1706d582007-10-14 00:38:15 -0700330 int err = -ENOENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
Joe Perchesbc578a52008-03-28 16:35:27 -0700332 if (qp->q.last_in & INET_FRAG_COMPLETE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 goto err;
334
Herbert Xu89cee8b2005-12-13 23:14:27 -0800335 if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
Herbert Xu1706d582007-10-14 00:38:15 -0700336 unlikely(ip_frag_too_far(qp)) &&
337 unlikely(err = ip_frag_reinit(qp))) {
Herbert Xu89cee8b2005-12-13 23:14:27 -0800338 ipq_kill(qp);
339 goto err;
340 }
341
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700342 offset = ntohs(ip_hdr(skb)->frag_off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 flags = offset & ~IP_OFFSET;
344 offset &= IP_OFFSET;
345 offset <<= 3; /* offset is in 8-byte chunks */
Arnaldo Carvalho de Meloc9bdd4b2007-03-12 20:09:15 -0300346 ihl = ip_hdrlen(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
348 /* Determine the position of this fragment. */
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900349 end = offset + skb->len - ihl;
Herbert Xu1706d582007-10-14 00:38:15 -0700350 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351
352 /* Is this the final fragment? */
353 if ((flags & IP_MF) == 0) {
354 /* If we already have some bits beyond end
355 * or have different end, the segment is corrrupted.
356 */
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700357 if (end < qp->q.len ||
Joe Perchesbc578a52008-03-28 16:35:27 -0700358 ((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 goto err;
Joe Perchesbc578a52008-03-28 16:35:27 -0700360 qp->q.last_in |= INET_FRAG_LAST_IN;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700361 qp->q.len = end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 } else {
363 if (end&7) {
364 end &= ~7;
365 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
366 skb->ip_summed = CHECKSUM_NONE;
367 }
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700368 if (end > qp->q.len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 /* Some bits beyond end -> corruption. */
Joe Perchesbc578a52008-03-28 16:35:27 -0700370 if (qp->q.last_in & INET_FRAG_LAST_IN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 goto err;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700372 qp->q.len = end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 }
374 }
375 if (end == offset)
376 goto err;
377
Herbert Xu1706d582007-10-14 00:38:15 -0700378 err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 if (pskb_pull(skb, ihl) == NULL)
380 goto err;
Herbert Xu1706d582007-10-14 00:38:15 -0700381
382 err = pskb_trim_rcsum(skb, end - offset);
383 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 goto err;
385
386 /* Find out which fragments are in front and at the back of us
387 * in the chain of fragments so far. We must know where to put
388 * this fragment, right?
389 */
Changli Gaod6bebca2010-06-29 04:39:37 +0000390 prev = qp->q.fragments_tail;
391 if (!prev || FRAG_CB(prev)->offset < offset) {
392 next = NULL;
393 goto found;
394 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 prev = NULL;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700396 for (next = qp->q.fragments; next != NULL; next = next->next) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 if (FRAG_CB(next)->offset >= offset)
398 break; /* bingo! */
399 prev = next;
400 }
401
Changli Gaod6bebca2010-06-29 04:39:37 +0000402found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 /* We found where to put this one. Check for overlap with
404 * preceding fragment, and, if needed, align things so that
405 * any overlaps are eliminated.
406 */
407 if (prev) {
408 int i = (FRAG_CB(prev)->offset + prev->len) - offset;
409
410 if (i > 0) {
411 offset += i;
Herbert Xu1706d582007-10-14 00:38:15 -0700412 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 if (end <= offset)
414 goto err;
Herbert Xu1706d582007-10-14 00:38:15 -0700415 err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 if (!pskb_pull(skb, i))
417 goto err;
418 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
419 skb->ip_summed = CHECKSUM_NONE;
420 }
421 }
422
Herbert Xu1706d582007-10-14 00:38:15 -0700423 err = -ENOMEM;
424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 while (next && FRAG_CB(next)->offset < end) {
426 int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
427
428 if (i < next->len) {
429 /* Eat head of the next overlapped fragment
430 * and leave the loop. The next ones cannot overlap.
431 */
432 if (!pskb_pull(next, i))
433 goto err;
434 FRAG_CB(next)->offset += i;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700435 qp->q.meat -= i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 if (next->ip_summed != CHECKSUM_UNNECESSARY)
437 next->ip_summed = CHECKSUM_NONE;
438 break;
439 } else {
440 struct sk_buff *free_it = next;
441
Peter Zijlstra47c6bf772006-12-12 19:48:59 +0100442 /* Old fragment is completely overridden with
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 * new one drop it.
444 */
445 next = next->next;
446
447 if (prev)
448 prev->next = next;
449 else
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700450 qp->q.fragments = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700452 qp->q.meat -= free_it->len;
Eric Dumazeta95d8c82010-06-13 23:22:43 +0000453 frag_kfree_skb(qp->q.net, free_it);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 }
455 }
456
457 FRAG_CB(skb)->offset = offset;
458
459 /* Insert this fragment in the chain of fragments. */
460 skb->next = next;
Changli Gaod6bebca2010-06-29 04:39:37 +0000461 if (!next)
462 qp->q.fragments_tail = skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 if (prev)
464 prev->next = skb;
465 else
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700466 qp->q.fragments = skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Herbert Xu1706d582007-10-14 00:38:15 -0700468 dev = skb->dev;
469 if (dev) {
470 qp->iif = dev->ifindex;
471 skb->dev = NULL;
472 }
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700473 qp->q.stamp = skb->tstamp;
474 qp->q.meat += skb->len;
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800475 atomic_add(skb->truesize, &qp->q.net->mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 if (offset == 0)
Joe Perchesbc578a52008-03-28 16:35:27 -0700477 qp->q.last_in |= INET_FRAG_FIRST_IN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Joe Perchesbc578a52008-03-28 16:35:27 -0700479 if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
480 qp->q.meat == qp->q.len)
Herbert Xu1706d582007-10-14 00:38:15 -0700481 return ip_frag_reasm(qp, prev, dev);
482
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700483 write_lock(&ip4_frags.lock);
Pavel Emelyanov3140c252008-01-22 06:11:48 -0800484 list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list);
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700485 write_unlock(&ip4_frags.lock);
Herbert Xu1706d582007-10-14 00:38:15 -0700486 return -EINPROGRESS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487
488err:
489 kfree_skb(skb);
Herbert Xu1706d582007-10-14 00:38:15 -0700490 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491}
492
493
494/* Build a new IP datagram from all its fragments. */
495
Herbert Xu1706d582007-10-14 00:38:15 -0700496static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
497 struct net_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498{
Jorge Boncompte [DTI2]2bad35b2009-03-18 23:26:11 -0700499 struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 struct iphdr *iph;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700501 struct sk_buff *fp, *head = qp->q.fragments;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 int len;
503 int ihlen;
Herbert Xu1706d582007-10-14 00:38:15 -0700504 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506 ipq_kill(qp);
507
Herbert Xu1706d582007-10-14 00:38:15 -0700508 /* Make the one we just received the head. */
509 if (prev) {
510 head = prev->next;
511 fp = skb_clone(head, GFP_ATOMIC);
Herbert Xu1706d582007-10-14 00:38:15 -0700512 if (!fp)
513 goto out_nomem;
514
515 fp->next = head->next;
Changli Gaod6bebca2010-06-29 04:39:37 +0000516 if (!fp->next)
517 qp->q.fragments_tail = fp;
Herbert Xu1706d582007-10-14 00:38:15 -0700518 prev->next = fp;
519
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700520 skb_morph(head, qp->q.fragments);
521 head->next = qp->q.fragments->next;
Herbert Xu1706d582007-10-14 00:38:15 -0700522
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700523 kfree_skb(qp->q.fragments);
524 qp->q.fragments = head;
Herbert Xu1706d582007-10-14 00:38:15 -0700525 }
526
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700527 WARN_ON(head == NULL);
528 WARN_ON(FRAG_CB(head)->offset != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
530 /* Allocate a new buffer for the datagram. */
Arnaldo Carvalho de Meloc9bdd4b2007-03-12 20:09:15 -0300531 ihlen = ip_hdrlen(head);
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700532 len = ihlen + qp->q.len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Herbert Xu1706d582007-10-14 00:38:15 -0700534 err = -E2BIG;
Stephen Hemminger132adf52007-03-08 20:44:43 -0800535 if (len > 65535)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 goto out_oversize;
537
538 /* Head of list must not be cloned. */
539 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
540 goto out_nomem;
541
542 /* If the first fragment is fragmented itself, we split
543 * it to two chunks: the first with data and paged part
544 * and the second, holding only fragments. */
David S. Miller21dc3302010-08-23 00:13:46 -0700545 if (skb_has_frag_list(head)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 struct sk_buff *clone;
547 int i, plen = 0;
548
549 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
550 goto out_nomem;
551 clone->next = head->next;
552 head->next = clone;
553 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
David S. Millerd7fcf1a2009-06-09 00:19:37 -0700554 skb_frag_list_init(head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
556 plen += skb_shinfo(head)->frags[i].size;
557 clone->len = clone->data_len = head->data_len - plen;
558 head->data_len -= clone->len;
559 head->len -= clone->len;
560 clone->csum = 0;
561 clone->ip_summed = head->ip_summed;
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800562 atomic_add(clone->truesize, &qp->q.net->mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
564
565 skb_shinfo(head)->frag_list = head->next;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700566 skb_push(head, head->data - skb_network_header(head));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 for (fp=head->next; fp; fp = fp->next) {
569 head->data_len += fp->len;
570 head->len += fp->len;
571 if (head->ip_summed != fp->ip_summed)
572 head->ip_summed = CHECKSUM_NONE;
Patrick McHardy84fa7932006-08-29 16:44:56 -0700573 else if (head->ip_summed == CHECKSUM_COMPLETE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 head->csum = csum_add(head->csum, fp->csum);
575 head->truesize += fp->truesize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 }
Eric Dumazetd27f9b32010-06-13 23:02:24 +0000577 atomic_sub(head->truesize, &qp->q.net->mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579 head->next = NULL;
580 head->dev = dev;
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700581 head->tstamp = qp->q.stamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700583 iph = ip_hdr(head);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 iph->frag_off = 0;
585 iph->tot_len = htons(len);
Jorge Boncompte [DTI2]2bad35b2009-03-18 23:26:11 -0700586 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700587 qp->q.fragments = NULL;
Changli Gaod6bebca2010-06-29 04:39:37 +0000588 qp->q.fragments_tail = NULL;
Herbert Xu1706d582007-10-14 00:38:15 -0700589 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
591out_nomem:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900592 LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
Patrick McHardy64ce2072005-08-09 20:50:53 -0700593 "queue %p\n", qp);
David Howells45542472007-10-17 21:37:22 -0700594 err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 goto out_fail;
596out_oversize:
597 if (net_ratelimit())
Harvey Harrison673d57e2008-10-31 00:53:57 -0700598 printk(KERN_INFO "Oversized IP packet from %pI4.\n",
599 &qp->saddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600out_fail:
David Fordbbf31bf2009-11-29 23:02:22 -0800601 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
Herbert Xu1706d582007-10-14 00:38:15 -0700602 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603}
604
605/* Process an incoming IP datagram fragment. */
Herbert Xu776c7292007-10-14 00:38:32 -0700606int ip_defrag(struct sk_buff *skb, u32 user)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 struct ipq *qp;
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800609 struct net *net;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900610
Eric Dumazetadf30902009-06-02 05:19:30 +0000611 net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev);
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700612 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
614 /* Start by cleaning up the memory. */
Pavel Emelyanove31e0bdc72008-01-22 06:10:13 -0800615 if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800616 ip_evictor(net);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 /* Lookup (or create) queue header */
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800619 if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
Herbert Xu1706d582007-10-14 00:38:15 -0700620 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700622 spin_lock(&qp->q.lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Herbert Xu1706d582007-10-14 00:38:15 -0700624 ret = ip_frag_queue(qp, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
Pavel Emelyanov5ab11c92007-10-15 02:24:19 -0700626 spin_unlock(&qp->q.lock);
Pavel Emelyanov4b6cb5d2007-10-15 02:41:09 -0700627 ipq_put(qp);
Herbert Xu776c7292007-10-14 00:38:32 -0700628 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 }
630
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700631 IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 kfree_skb(skb);
Herbert Xu776c7292007-10-14 00:38:32 -0700633 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634}
Eric Dumazet4bc2f182010-07-09 21:22:10 +0000635EXPORT_SYMBOL(ip_defrag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800637#ifdef CONFIG_SYSCTL
638static int zero;
639
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700640static struct ctl_table ip4_frags_ns_ctl_table[] = {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800641 {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800642 .procname = "ipfrag_high_thresh",
Pavel Emelyanove31e0bdc72008-01-22 06:10:13 -0800643 .data = &init_net.ipv4.frags.high_thresh,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800644 .maxlen = sizeof(int),
645 .mode = 0644,
Alexey Dobriyan6d9f2392008-11-03 18:21:05 -0800646 .proc_handler = proc_dointvec
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800647 },
648 {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800649 .procname = "ipfrag_low_thresh",
Pavel Emelyanove31e0bdc72008-01-22 06:10:13 -0800650 .data = &init_net.ipv4.frags.low_thresh,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800651 .maxlen = sizeof(int),
652 .mode = 0644,
Alexey Dobriyan6d9f2392008-11-03 18:21:05 -0800653 .proc_handler = proc_dointvec
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800654 },
655 {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800656 .procname = "ipfrag_time",
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800657 .data = &init_net.ipv4.frags.timeout,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800658 .maxlen = sizeof(int),
659 .mode = 0644,
Alexey Dobriyan6d9f2392008-11-03 18:21:05 -0800660 .proc_handler = proc_dointvec_jiffies,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800661 },
Pavel Emelyanov7d291eb2008-05-19 13:53:02 -0700662 { }
663};
664
665static struct ctl_table ip4_frags_ctl_table[] = {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800666 {
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800667 .procname = "ipfrag_secret_interval",
Pavel Emelyanov3b4bc4a2008-01-22 06:11:04 -0800668 .data = &ip4_frags.secret_interval,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800669 .maxlen = sizeof(int),
670 .mode = 0644,
Alexey Dobriyan6d9f2392008-11-03 18:21:05 -0800671 .proc_handler = proc_dointvec_jiffies,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800672 },
673 {
674 .procname = "ipfrag_max_dist",
675 .data = &sysctl_ipfrag_max_dist,
676 .maxlen = sizeof(int),
677 .mode = 0644,
Alexey Dobriyan6d9f2392008-11-03 18:21:05 -0800678 .proc_handler = proc_dointvec_minmax,
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800679 .extra1 = &zero
680 },
681 { }
682};
683
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000684static int __net_init ip4_frags_ns_ctl_register(struct net *net)
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800685{
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800686 struct ctl_table *table;
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800687 struct ctl_table_header *hdr;
688
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700689 table = ip4_frags_ns_ctl_table;
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800690 if (!net_eq(net, &init_net)) {
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700691 table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800692 if (table == NULL)
693 goto err_alloc;
694
Pavel Emelyanove31e0bdc72008-01-22 06:10:13 -0800695 table[0].data = &net->ipv4.frags.high_thresh;
696 table[1].data = &net->ipv4.frags.low_thresh;
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800697 table[2].data = &net->ipv4.frags.timeout;
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800698 }
699
700 hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table);
701 if (hdr == NULL)
702 goto err_reg;
703
704 net->ipv4.frags_hdr = hdr;
705 return 0;
706
707err_reg:
Octavian Purdila09ad9bc2009-11-25 15:14:13 -0800708 if (!net_eq(net, &init_net))
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800709 kfree(table);
710err_alloc:
711 return -ENOMEM;
712}
713
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000714static void __net_exit ip4_frags_ns_ctl_unregister(struct net *net)
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800715{
716 struct ctl_table *table;
717
718 table = net->ipv4.frags_hdr->ctl_table_arg;
719 unregister_net_sysctl_table(net->ipv4.frags_hdr);
720 kfree(table);
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800721}
Pavel Emelyanov7d291eb2008-05-19 13:53:02 -0700722
723static void ip4_frags_ctl_register(void)
724{
725 register_net_sysctl_rotable(net_ipv4_ctl_path, ip4_frags_ctl_table);
726}
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800727#else
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700728static inline int ip4_frags_ns_ctl_register(struct net *net)
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800729{
730 return 0;
731}
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800732
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700733static inline void ip4_frags_ns_ctl_unregister(struct net *net)
Pavel Emelyanove4a2d5c2008-01-22 06:08:36 -0800734{
735}
Pavel Emelyanov7d291eb2008-05-19 13:53:02 -0700736
737static inline void ip4_frags_ctl_register(void)
738{
739}
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800740#endif
741
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000742static int __net_init ipv4_frags_init_net(struct net *net)
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800743{
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800744 /*
Pavel Emelyanove31e0bdc72008-01-22 06:10:13 -0800745 * Fragment cache limits. We will commit 256K at one time. Should we
746 * cross that limit we will prune down to 192K. This should cope with
747 * even the most extreme cases without allowing an attacker to
748 * measurably harm machine performance.
749 */
750 net->ipv4.frags.high_thresh = 256 * 1024;
751 net->ipv4.frags.low_thresh = 192 * 1024;
752 /*
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800753 * Important NOTE! Fragment queue must be destroyed before MSL expires.
754 * RFC791 is wrong proposing to prolongate timer each fragment arrival
755 * by TTL.
756 */
757 net->ipv4.frags.timeout = IP_FRAG_TIME;
758
Pavel Emelyanove5a2bb82008-01-22 06:06:23 -0800759 inet_frags_init_net(&net->ipv4.frags);
760
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700761 return ip4_frags_ns_ctl_register(net);
Pavel Emelyanov8d8354d2008-01-22 05:58:31 -0800762}
763
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000764static void __net_exit ipv4_frags_exit_net(struct net *net)
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800765{
Pavel Emelyanov0a64b4b2008-05-19 13:51:29 -0700766 ip4_frags_ns_ctl_unregister(net);
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800767 inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
768}
769
770static struct pernet_operations ip4_frags_ops = {
771 .init = ipv4_frags_init_net,
772 .exit = ipv4_frags_exit_net,
773};
774
Eric Dumazetb7aa0bf2007-04-19 16:16:32 -0700775void __init ipfrag_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776{
Pavel Emelyanov7d291eb2008-05-19 13:53:02 -0700777 ip4_frags_ctl_register();
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800778 register_pernet_subsys(&ip4_frags_ops);
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700779 ip4_frags.hashfn = ip4_hashfn;
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700780 ip4_frags.constructor = ip4_frag_init;
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700781 ip4_frags.destructor = ip4_frag_free;
782 ip4_frags.skb_free = NULL;
783 ip4_frags.qsize = sizeof(struct ipq);
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700784 ip4_frags.match = ip4_frag_match;
Pavel Emelyanove521db92007-10-17 19:45:23 -0700785 ip4_frags.frag_expire = ip_expire;
Pavel Emelyanov3b4bc4a2008-01-22 06:11:04 -0800786 ip4_frags.secret_interval = 10 * 60 * HZ;
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700787 inet_frags_init(&ip4_frags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788}