blob: e7920352646aed0a0680557babecfb586283ce92 [file] [log] [blame]
Pavel Emelyanov7eb95152007-10-15 02:31:52 -07001/*
2 * inet fragments management
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Pavel Emelyanov <xemul@openvz.org>
10 * Started as consolidation of ipv4/ip_fragment.c,
11 * ipv6/reassembly. and ipv6 nf conntrack reassembly
12 */
13
14#include <linux/list.h>
15#include <linux/spinlock.h>
16#include <linux/module.h>
17#include <linux/timer.h>
18#include <linux/mm.h>
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070019#include <linux/random.h>
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -070020#include <linux/skbuff.h>
21#include <linux/rtnetlink.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/slab.h>
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070023
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +000024#include <net/sock.h>
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070025#include <net/inet_frag.h>
Hannes Frederic Sowabe991972013-03-22 08:24:37 +000026#include <net/inet_ecn.h>
27
Florian Westphalb13d3cb2014-07-24 16:50:32 +020028#define INETFRAGS_EVICT_BUCKETS 128
29#define INETFRAGS_EVICT_MAX 512
30
Florian Westphale3a57d12014-07-24 16:50:35 +020031/* don't rebuild inetfrag table with new secret more often than this */
32#define INETFRAGS_MIN_REBUILD_INTERVAL (5 * HZ)
33
Hannes Frederic Sowabe991972013-03-22 08:24:37 +000034/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
35 * Value : 0xff if frame should be dropped.
36 * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field
37 */
38const u8 ip_frag_ecn_table[16] = {
39 /* at least one fragment had CE, and others ECT_0 or ECT_1 */
40 [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE,
41 [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
42 [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE,
43
44 /* invalid combinations : drop frame */
45 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
46 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
47 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
48 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
49 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
50 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
51 [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
52};
53EXPORT_SYMBOL(ip_frag_ecn_table);
Pavel Emelyanov7eb95152007-10-15 02:31:52 -070054
Florian Westphalfb3cfe62014-07-24 16:50:30 +020055static unsigned int
56inet_frag_hashfn(const struct inet_frags *f, const struct inet_frag_queue *q)
57{
58 return f->hashfn(q) & (INETFRAGS_HASHSZ - 1);
59}
60
Florian Westphale3a57d12014-07-24 16:50:35 +020061static bool inet_frag_may_rebuild(struct inet_frags *f)
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070062{
Florian Westphale3a57d12014-07-24 16:50:35 +020063 return time_after(jiffies,
64 f->last_rebuild_jiffies + INETFRAGS_MIN_REBUILD_INTERVAL);
65}
66
67static void inet_frag_secret_rebuild(struct inet_frags *f)
68{
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070069 int i;
70
Florian Westphalab1c7242014-07-24 16:50:36 +020071 write_seqlock_bh(&f->rnd_seqlock);
Florian Westphale3a57d12014-07-24 16:50:35 +020072
73 if (!inet_frag_may_rebuild(f))
74 goto out;
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000075
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070076 get_random_bytes(&f->rnd, sizeof(u32));
Florian Westphale3a57d12014-07-24 16:50:35 +020077
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070078 for (i = 0; i < INETFRAGS_HASHSZ; i++) {
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000079 struct inet_frag_bucket *hb;
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070080 struct inet_frag_queue *q;
Sasha Levinb67bfe02013-02-27 17:06:00 -080081 struct hlist_node *n;
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070082
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000083 hb = &f->hash[i];
Florian Westphalab1c7242014-07-24 16:50:36 +020084 spin_lock(&hb->chain_lock);
85
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000086 hlist_for_each_entry_safe(q, n, &hb->chain, list) {
Florian Westphalfb3cfe62014-07-24 16:50:30 +020087 unsigned int hval = inet_frag_hashfn(f, q);
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070088
89 if (hval != i) {
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000090 struct inet_frag_bucket *hb_dest;
91
Pavel Emelyanov321a3a92007-10-15 02:38:08 -070092 hlist_del(&q->list);
93
94 /* Relink to new hash chain. */
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +000095 hb_dest = &f->hash[hval];
Florian Westphalab1c7242014-07-24 16:50:36 +020096
97 /* This is the only place where we take
98 * another chain_lock while already holding
99 * one. As this will not run concurrently,
100 * we cannot deadlock on hb_dest lock below, if its
101 * already locked it will be released soon since
102 * other caller cannot be waiting for hb lock
103 * that we've taken above.
104 */
105 spin_lock_nested(&hb_dest->chain_lock,
106 SINGLE_DEPTH_NESTING);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000107 hlist_add_head(&q->list, &hb_dest->chain);
Florian Westphalab1c7242014-07-24 16:50:36 +0200108 spin_unlock(&hb_dest->chain_lock);
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700109 }
110 }
Florian Westphalab1c7242014-07-24 16:50:36 +0200111 spin_unlock(&hb->chain_lock);
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700112 }
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700113
Florian Westphale3a57d12014-07-24 16:50:35 +0200114 f->rebuild = false;
115 f->last_rebuild_jiffies = jiffies;
116out:
Florian Westphalab1c7242014-07-24 16:50:36 +0200117 write_sequnlock_bh(&f->rnd_seqlock);
Pavel Emelyanov321a3a92007-10-15 02:38:08 -0700118}
119
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200120static bool inet_fragq_should_evict(const struct inet_frag_queue *q)
121{
122 return q->net->low_thresh == 0 ||
123 frag_mem_limit(q->net) >= q->net->low_thresh;
124}
125
126static unsigned int
127inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
128{
129 struct inet_frag_queue *fq;
130 struct hlist_node *n;
131 unsigned int evicted = 0;
132 HLIST_HEAD(expired);
133
134evict_again:
135 spin_lock(&hb->chain_lock);
136
137 hlist_for_each_entry_safe(fq, n, &hb->chain, list) {
138 if (!inet_fragq_should_evict(fq))
139 continue;
140
141 if (!del_timer(&fq->timer)) {
142 /* q expiring right now thus increment its refcount so
143 * it won't be freed under us and wait until the timer
144 * has finished executing then destroy it
145 */
146 atomic_inc(&fq->refcnt);
147 spin_unlock(&hb->chain_lock);
148 del_timer_sync(&fq->timer);
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200149 inet_frag_put(fq, f);
150 goto evict_again;
151 }
152
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200153 fq->flags |= INET_FRAG_EVICTED;
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200154 hlist_del(&fq->list);
155 hlist_add_head(&fq->list, &expired);
156 ++evicted;
157 }
158
159 spin_unlock(&hb->chain_lock);
160
161 hlist_for_each_entry_safe(fq, n, &expired, list)
162 f->frag_expire((unsigned long) fq);
163
164 return evicted;
165}
166
167static void inet_frag_worker(struct work_struct *work)
168{
169 unsigned int budget = INETFRAGS_EVICT_BUCKETS;
170 unsigned int i, evicted = 0;
171 struct inet_frags *f;
172
173 f = container_of(work, struct inet_frags, frags_work);
174
175 BUILD_BUG_ON(INETFRAGS_EVICT_BUCKETS >= INETFRAGS_HASHSZ);
176
Florian Westphalab1c7242014-07-24 16:50:36 +0200177 local_bh_disable();
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200178
179 for (i = ACCESS_ONCE(f->next_bucket); budget; --budget) {
180 evicted += inet_evict_bucket(f, &f->hash[i]);
181 i = (i + 1) & (INETFRAGS_HASHSZ - 1);
182 if (evicted > INETFRAGS_EVICT_MAX)
183 break;
184 }
185
186 f->next_bucket = i;
187
Florian Westphalab1c7242014-07-24 16:50:36 +0200188 local_bh_enable();
189
Florian Westphale3a57d12014-07-24 16:50:35 +0200190 if (f->rebuild && inet_frag_may_rebuild(f))
191 inet_frag_secret_rebuild(f);
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200192}
193
194static void inet_frag_schedule_worker(struct inet_frags *f)
195{
196 if (unlikely(!work_pending(&f->frags_work)))
197 schedule_work(&f->frags_work);
198}
199
Nikolay Aleksandrovd4ad4d22014-08-01 12:29:48 +0200200int inet_frags_init(struct inet_frags *f)
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700201{
202 int i;
203
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200204 INIT_WORK(&f->frags_work, inet_frag_worker);
205
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000206 for (i = 0; i < INETFRAGS_HASHSZ; i++) {
207 struct inet_frag_bucket *hb = &f->hash[i];
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700208
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000209 spin_lock_init(&hb->chain_lock);
210 INIT_HLIST_HEAD(&hb->chain);
211 }
Florian Westphalab1c7242014-07-24 16:50:36 +0200212
213 seqlock_init(&f->rnd_seqlock);
Florian Westphale3a57d12014-07-24 16:50:35 +0200214 f->last_rebuild_jiffies = 0;
Nikolay Aleksandrovd4ad4d22014-08-01 12:29:48 +0200215 f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0,
216 NULL);
217 if (!f->frags_cachep)
218 return -ENOMEM;
219
220 return 0;
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700221}
222EXPORT_SYMBOL(inet_frags_init);
223
Pavel Emelyanove5a2bb82008-01-22 06:06:23 -0800224void inet_frags_init_net(struct netns_frags *nf)
225{
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000226 init_frag_mem_limit(nf);
Pavel Emelyanove5a2bb82008-01-22 06:06:23 -0800227}
228EXPORT_SYMBOL(inet_frags_init_net);
229
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700230void inet_frags_fini(struct inet_frags *f)
231{
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200232 cancel_work_sync(&f->frags_work);
Nikolay Aleksandrovd4ad4d22014-08-01 12:29:48 +0200233 kmem_cache_destroy(f->frags_cachep);
Pavel Emelyanov7eb95152007-10-15 02:31:52 -0700234}
235EXPORT_SYMBOL(inet_frags_fini);
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700236
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800237void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
238{
Florian Westphalab1c7242014-07-24 16:50:36 +0200239 unsigned int seq;
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200240 int i;
241
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800242 nf->low_thresh = 0;
Florian Westphalab1c7242014-07-24 16:50:36 +0200243 local_bh_disable();
David S. Millere8e16b702008-03-28 17:30:18 -0700244
Florian Westphalab1c7242014-07-24 16:50:36 +0200245evict_again:
246 seq = read_seqbegin(&f->rnd_seqlock);
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200247
248 for (i = 0; i < INETFRAGS_HASHSZ ; i++)
249 inet_evict_bucket(f, &f->hash[i]);
250
Florian Westphalab1c7242014-07-24 16:50:36 +0200251 if (read_seqretry(&f->rnd_seqlock, seq))
252 goto evict_again;
253
254 local_bh_enable();
Jesper Dangaard Brouer6d7b8572013-01-28 23:45:33 +0000255
256 percpu_counter_destroy(&nf->mem);
Pavel Emelyanov81566e82008-01-22 06:12:39 -0800257}
258EXPORT_SYMBOL(inet_frags_exit_net);
259
Florian Westphalab1c7242014-07-24 16:50:36 +0200260static struct inet_frag_bucket *
261get_frag_bucket_locked(struct inet_frag_queue *fq, struct inet_frags *f)
262__acquires(hb->chain_lock)
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700263{
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000264 struct inet_frag_bucket *hb;
Florian Westphalab1c7242014-07-24 16:50:36 +0200265 unsigned int seq, hash;
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000266
Florian Westphalab1c7242014-07-24 16:50:36 +0200267 restart:
268 seq = read_seqbegin(&f->rnd_seqlock);
269
Florian Westphalfb3cfe62014-07-24 16:50:30 +0200270 hash = inet_frag_hashfn(f, fq);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000271 hb = &f->hash[hash];
272
273 spin_lock(&hb->chain_lock);
Florian Westphalab1c7242014-07-24 16:50:36 +0200274 if (read_seqretry(&f->rnd_seqlock, seq)) {
275 spin_unlock(&hb->chain_lock);
276 goto restart;
277 }
278
279 return hb;
280}
281
282static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
283{
284 struct inet_frag_bucket *hb;
285
286 hb = get_frag_bucket_locked(fq, f);
Nikolay Aleksandrov65ba1f12014-10-28 10:30:34 +0100287 if (!(fq->flags & INET_FRAG_EVICTED))
288 hlist_del(&fq->list);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000289 spin_unlock(&hb->chain_lock);
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700290}
291
292void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
293{
294 if (del_timer(&fq->timer))
295 atomic_dec(&fq->refcnt);
296
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200297 if (!(fq->flags & INET_FRAG_COMPLETE)) {
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700298 fq_unlink(fq, f);
299 atomic_dec(&fq->refcnt);
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200300 fq->flags |= INET_FRAG_COMPLETE;
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700301 }
302}
Pavel Emelyanov277e6502007-10-15 02:37:18 -0700303EXPORT_SYMBOL(inet_frag_kill);
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700304
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800305static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f,
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200306 struct sk_buff *skb)
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700307{
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700308 if (f->skb_free)
309 f->skb_free(skb);
310 kfree_skb(skb);
311}
312
Florian Westphal3fd588e2014-07-24 16:50:34 +0200313void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f)
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700314{
315 struct sk_buff *fp;
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800316 struct netns_frags *nf;
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000317 unsigned int sum, sum_truesize = 0;
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700318
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200319 WARN_ON(!(q->flags & INET_FRAG_COMPLETE));
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700320 WARN_ON(del_timer(&q->timer) != 0);
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700321
322 /* Release all fragment data. */
323 fp = q->fragments;
Pavel Emelyanov6ddc0822008-01-22 06:07:25 -0800324 nf = q->net;
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700325 while (fp) {
326 struct sk_buff *xp = fp->next;
327
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000328 sum_truesize += fp->truesize;
329 frag_kfree_skb(nf, f, fp);
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700330 fp = xp;
331 }
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000332 sum = sum_truesize + f->qsize;
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000333 sub_frag_mem_limit(q, sum);
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700334
Pavel Emelyanovc9547702007-10-17 19:48:26 -0700335 if (f->destructor)
336 f->destructor(q);
Nikolay Aleksandrovd4ad4d22014-08-01 12:29:48 +0200337 kmem_cache_free(f->frags_cachep, q);
Pavel Emelyanov1e4b8282007-10-15 02:39:14 -0700338}
339EXPORT_SYMBOL(inet_frag_destroy);
Pavel Emelyanov8e7999c2007-10-15 02:40:06 -0700340
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800341static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
Nikolay Aleksandrovf926e232014-08-01 12:29:46 +0200342 struct inet_frag_queue *qp_in,
343 struct inet_frags *f,
344 void *arg)
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700345{
Florian Westphalab1c7242014-07-24 16:50:36 +0200346 struct inet_frag_bucket *hb = get_frag_bucket_locked(qp_in, f);
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700347 struct inet_frag_queue *qp;
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000348
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700349#ifdef CONFIG_SMP
350 /* With SMP race we have to recheck hash table, because
Florian Westphalab1c7242014-07-24 16:50:36 +0200351 * such entry could have been created on other cpu before
352 * we acquired hash bucket lock.
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700353 */
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000354 hlist_for_each_entry(qp, &hb->chain, list) {
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800355 if (qp->net == nf && f->match(qp, arg)) {
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700356 atomic_inc(&qp->refcnt);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000357 spin_unlock(&hb->chain_lock);
Nikolay Aleksandrov06aa8b82014-08-01 12:29:44 +0200358 qp_in->flags |= INET_FRAG_COMPLETE;
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700359 inet_frag_put(qp_in, f);
360 return qp;
361 }
362 }
363#endif
364 qp = qp_in;
Pavel Emelyanovb2fd5322008-01-22 06:09:37 -0800365 if (!mod_timer(&qp->timer, jiffies + nf->timeout))
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700366 atomic_inc(&qp->refcnt);
367
368 atomic_inc(&qp->refcnt);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000369 hlist_add_head(&qp->list, &hb->chain);
Florian Westphal3fd588e2014-07-24 16:50:34 +0200370
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000371 spin_unlock(&hb->chain_lock);
Nikolay Aleksandrov24b9bf42014-03-03 23:19:18 +0100372
Pavel Emelyanov2588fe12007-10-17 19:44:34 -0700373 return qp;
374}
Pavel Emelyanove521db92007-10-17 19:45:23 -0700375
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800376static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
Nikolay Aleksandrovf926e232014-08-01 12:29:46 +0200377 struct inet_frags *f,
378 void *arg)
Pavel Emelyanove521db92007-10-17 19:45:23 -0700379{
380 struct inet_frag_queue *q;
381
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200382 if (frag_mem_limit(nf) > nf->high_thresh) {
383 inet_frag_schedule_worker(f);
Florian Westphal86e93e42014-07-24 16:50:31 +0200384 return NULL;
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200385 }
Florian Westphal86e93e42014-07-24 16:50:31 +0200386
Nikolay Aleksandrovd4ad4d22014-08-01 12:29:48 +0200387 q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC);
Pavel Emelyanove521db92007-10-17 19:45:23 -0700388 if (q == NULL)
389 return NULL;
390
Gao feng54db0cc2012-06-08 01:21:40 +0000391 q->net = nf;
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700392 f->constructor(q, arg);
Jesper Dangaard Brouerd4336732013-01-28 23:45:12 +0000393 add_frag_mem_limit(q, f->qsize);
394
Pavel Emelyanove521db92007-10-17 19:45:23 -0700395 setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
396 spin_lock_init(&q->lock);
397 atomic_set(&q->refcnt, 1);
398
399 return q;
400}
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700401
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800402static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
Nikolay Aleksandrovf926e232014-08-01 12:29:46 +0200403 struct inet_frags *f,
404 void *arg)
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700405{
406 struct inet_frag_queue *q;
407
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800408 q = inet_frag_alloc(nf, f, arg);
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700409 if (q == NULL)
410 return NULL;
411
Pavel Emelyanov9a375802008-06-27 20:06:08 -0700412 return inet_frag_intern(nf, q, f, arg);
Pavel Emelyanovc6fda282007-10-17 19:46:47 -0700413}
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700414
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800415struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
Nikolay Aleksandrovf926e232014-08-01 12:29:46 +0200416 struct inet_frags *f, void *key,
417 unsigned int hash)
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700418{
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000419 struct inet_frag_bucket *hb;
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700420 struct inet_frag_queue *q;
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +0000421 int depth = 0;
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700422
Florian Westphalb13d3cb2014-07-24 16:50:32 +0200423 if (frag_mem_limit(nf) > nf->low_thresh)
424 inet_frag_schedule_worker(f);
Florian Westphal86e93e42014-07-24 16:50:31 +0200425
Florian Westphalfb3cfe62014-07-24 16:50:30 +0200426 hash &= (INETFRAGS_HASHSZ - 1);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000427 hb = &f->hash[hash];
428
429 spin_lock(&hb->chain_lock);
430 hlist_for_each_entry(q, &hb->chain, list) {
Pavel Emelyanovac18e752008-01-22 06:02:14 -0800431 if (q->net == nf && f->match(q, key)) {
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700432 atomic_inc(&q->refcnt);
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000433 spin_unlock(&hb->chain_lock);
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700434 return q;
435 }
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +0000436 depth++;
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700437 }
Jesper Dangaard Brouer19952cc42013-04-03 23:38:16 +0000438 spin_unlock(&hb->chain_lock);
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700439
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +0000440 if (depth <= INETFRAGS_MAXDEPTH)
441 return inet_frag_create(nf, f, key);
Florian Westphale3a57d12014-07-24 16:50:35 +0200442
443 if (inet_frag_may_rebuild(f)) {
Florian Westphalab1c7242014-07-24 16:50:36 +0200444 if (!f->rebuild)
445 f->rebuild = true;
Florian Westphale3a57d12014-07-24 16:50:35 +0200446 inet_frag_schedule_worker(f);
447 }
448
449 return ERR_PTR(-ENOBUFS);
Pavel Emelyanovabd65232007-10-17 19:47:21 -0700450}
451EXPORT_SYMBOL(inet_frag_find);
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +0000452
453void inet_frag_maybe_warn_overflow(struct inet_frag_queue *q,
454 const char *prefix)
455{
456 static const char msg[] = "inet_frag_find: Fragment hash bucket"
457 " list length grew over limit " __stringify(INETFRAGS_MAXDEPTH)
458 ". Dropping fragment.\n";
459
460 if (PTR_ERR(q) == -ENOBUFS)
Joe Perchesba7a46f2014-11-11 10:59:17 -0800461 net_dbg_ratelimited("%s%s", prefix, msg);
Hannes Frederic Sowa5a3da1f2013-03-15 11:32:30 +0000462}
463EXPORT_SYMBOL(inet_frag_maybe_warn_overflow);