Commit | Line | Data |
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7eb95156 PE |
1 | /* |
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> | |
321a3a99 | 19 | #include <linux/random.h> |
1e4b8287 PE |
20 | #include <linux/skbuff.h> |
21 | #include <linux/rtnetlink.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
7eb95156 PE |
23 | |
24 | #include <net/inet_frag.h> | |
25 | ||
321a3a99 PE |
26 | static void inet_frag_secret_rebuild(unsigned long dummy) |
27 | { | |
28 | struct inet_frags *f = (struct inet_frags *)dummy; | |
29 | unsigned long now = jiffies; | |
30 | int i; | |
31 | ||
32 | write_lock(&f->lock); | |
33 | get_random_bytes(&f->rnd, sizeof(u32)); | |
34 | for (i = 0; i < INETFRAGS_HASHSZ; i++) { | |
35 | struct inet_frag_queue *q; | |
36 | struct hlist_node *p, *n; | |
37 | ||
38 | hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) { | |
39 | unsigned int hval = f->hashfn(q); | |
40 | ||
41 | if (hval != i) { | |
42 | hlist_del(&q->list); | |
43 | ||
44 | /* Relink to new hash chain. */ | |
45 | hlist_add_head(&q->list, &f->hash[hval]); | |
46 | } | |
47 | } | |
48 | } | |
49 | write_unlock(&f->lock); | |
50 | ||
3b4bc4a2 | 51 | mod_timer(&f->secret_timer, now + f->secret_interval); |
321a3a99 PE |
52 | } |
53 | ||
7eb95156 PE |
54 | void inet_frags_init(struct inet_frags *f) |
55 | { | |
56 | int i; | |
57 | ||
58 | for (i = 0; i < INETFRAGS_HASHSZ; i++) | |
59 | INIT_HLIST_HEAD(&f->hash[i]); | |
60 | ||
7eb95156 PE |
61 | rwlock_init(&f->lock); |
62 | ||
63 | f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^ | |
64 | (jiffies ^ (jiffies >> 6))); | |
65 | ||
b24b8a24 PE |
66 | setup_timer(&f->secret_timer, inet_frag_secret_rebuild, |
67 | (unsigned long)f); | |
3b4bc4a2 | 68 | f->secret_timer.expires = jiffies + f->secret_interval; |
321a3a99 | 69 | add_timer(&f->secret_timer); |
7eb95156 PE |
70 | } |
71 | EXPORT_SYMBOL(inet_frags_init); | |
72 | ||
e5a2bb84 PE |
73 | void inet_frags_init_net(struct netns_frags *nf) |
74 | { | |
75 | nf->nqueues = 0; | |
d433673e | 76 | init_frag_mem_limit(nf); |
3140c25c | 77 | INIT_LIST_HEAD(&nf->lru_list); |
e5a2bb84 PE |
78 | } |
79 | EXPORT_SYMBOL(inet_frags_init_net); | |
80 | ||
7eb95156 PE |
81 | void inet_frags_fini(struct inet_frags *f) |
82 | { | |
321a3a99 | 83 | del_timer(&f->secret_timer); |
7eb95156 PE |
84 | } |
85 | EXPORT_SYMBOL(inet_frags_fini); | |
277e650d | 86 | |
81566e83 PE |
87 | void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f) |
88 | { | |
89 | nf->low_thresh = 0; | |
e8e16b70 DM |
90 | |
91 | local_bh_disable(); | |
6b102865 | 92 | inet_frag_evictor(nf, f, true); |
e8e16b70 | 93 | local_bh_enable(); |
81566e83 PE |
94 | } |
95 | EXPORT_SYMBOL(inet_frags_exit_net); | |
96 | ||
277e650d PE |
97 | static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f) |
98 | { | |
99 | write_lock(&f->lock); | |
100 | hlist_del(&fq->list); | |
101 | list_del(&fq->lru_list); | |
e5a2bb84 | 102 | fq->net->nqueues--; |
277e650d PE |
103 | write_unlock(&f->lock); |
104 | } | |
105 | ||
106 | void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f) | |
107 | { | |
108 | if (del_timer(&fq->timer)) | |
109 | atomic_dec(&fq->refcnt); | |
110 | ||
bc578a54 | 111 | if (!(fq->last_in & INET_FRAG_COMPLETE)) { |
277e650d PE |
112 | fq_unlink(fq, f); |
113 | atomic_dec(&fq->refcnt); | |
bc578a54 | 114 | fq->last_in |= INET_FRAG_COMPLETE; |
277e650d PE |
115 | } |
116 | } | |
277e650d | 117 | EXPORT_SYMBOL(inet_frag_kill); |
1e4b8287 | 118 | |
6ddc0822 | 119 | static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f, |
d433673e | 120 | struct sk_buff *skb) |
1e4b8287 | 121 | { |
1e4b8287 PE |
122 | if (f->skb_free) |
123 | f->skb_free(skb); | |
124 | kfree_skb(skb); | |
125 | } | |
126 | ||
127 | void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f, | |
128 | int *work) | |
129 | { | |
130 | struct sk_buff *fp; | |
6ddc0822 | 131 | struct netns_frags *nf; |
d433673e | 132 | unsigned int sum, sum_truesize = 0; |
1e4b8287 | 133 | |
547b792c IJ |
134 | WARN_ON(!(q->last_in & INET_FRAG_COMPLETE)); |
135 | WARN_ON(del_timer(&q->timer) != 0); | |
1e4b8287 PE |
136 | |
137 | /* Release all fragment data. */ | |
138 | fp = q->fragments; | |
6ddc0822 | 139 | nf = q->net; |
1e4b8287 PE |
140 | while (fp) { |
141 | struct sk_buff *xp = fp->next; | |
142 | ||
d433673e JDB |
143 | sum_truesize += fp->truesize; |
144 | frag_kfree_skb(nf, f, fp); | |
1e4b8287 PE |
145 | fp = xp; |
146 | } | |
d433673e | 147 | sum = sum_truesize + f->qsize; |
1e4b8287 | 148 | if (work) |
d433673e JDB |
149 | *work -= sum; |
150 | sub_frag_mem_limit(q, sum); | |
1e4b8287 | 151 | |
c9547709 PE |
152 | if (f->destructor) |
153 | f->destructor(q); | |
154 | kfree(q); | |
1e4b8287 PE |
155 | |
156 | } | |
157 | EXPORT_SYMBOL(inet_frag_destroy); | |
8e7999c4 | 158 | |
6b102865 | 159 | int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force) |
8e7999c4 PE |
160 | { |
161 | struct inet_frag_queue *q; | |
162 | int work, evicted = 0; | |
163 | ||
6b102865 | 164 | if (!force) { |
d433673e | 165 | if (frag_mem_limit(nf) <= nf->high_thresh) |
6b102865 AW |
166 | return 0; |
167 | } | |
168 | ||
d433673e | 169 | work = frag_mem_limit(nf) - nf->low_thresh; |
8e7999c4 PE |
170 | while (work > 0) { |
171 | read_lock(&f->lock); | |
3140c25c | 172 | if (list_empty(&nf->lru_list)) { |
8e7999c4 PE |
173 | read_unlock(&f->lock); |
174 | break; | |
175 | } | |
176 | ||
3140c25c | 177 | q = list_first_entry(&nf->lru_list, |
8e7999c4 PE |
178 | struct inet_frag_queue, lru_list); |
179 | atomic_inc(&q->refcnt); | |
180 | read_unlock(&f->lock); | |
181 | ||
182 | spin_lock(&q->lock); | |
bc578a54 | 183 | if (!(q->last_in & INET_FRAG_COMPLETE)) |
8e7999c4 PE |
184 | inet_frag_kill(q, f); |
185 | spin_unlock(&q->lock); | |
186 | ||
187 | if (atomic_dec_and_test(&q->refcnt)) | |
188 | inet_frag_destroy(q, f, &work); | |
189 | evicted++; | |
190 | } | |
191 | ||
192 | return evicted; | |
193 | } | |
194 | EXPORT_SYMBOL(inet_frag_evictor); | |
2588fe1d | 195 | |
ac18e750 PE |
196 | static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf, |
197 | struct inet_frag_queue *qp_in, struct inet_frags *f, | |
9a375803 | 198 | void *arg) |
2588fe1d PE |
199 | { |
200 | struct inet_frag_queue *qp; | |
201 | #ifdef CONFIG_SMP | |
202 | struct hlist_node *n; | |
203 | #endif | |
9a375803 | 204 | unsigned int hash; |
2588fe1d PE |
205 | |
206 | write_lock(&f->lock); | |
9a375803 PE |
207 | /* |
208 | * While we stayed w/o the lock other CPU could update | |
209 | * the rnd seed, so we need to re-calculate the hash | |
210 | * chain. Fortunatelly the qp_in can be used to get one. | |
211 | */ | |
212 | hash = f->hashfn(qp_in); | |
2588fe1d PE |
213 | #ifdef CONFIG_SMP |
214 | /* With SMP race we have to recheck hash table, because | |
215 | * such entry could be created on other cpu, while we | |
216 | * promoted read lock to write lock. | |
217 | */ | |
218 | hlist_for_each_entry(qp, n, &f->hash[hash], list) { | |
ac18e750 | 219 | if (qp->net == nf && f->match(qp, arg)) { |
2588fe1d PE |
220 | atomic_inc(&qp->refcnt); |
221 | write_unlock(&f->lock); | |
bc578a54 | 222 | qp_in->last_in |= INET_FRAG_COMPLETE; |
2588fe1d PE |
223 | inet_frag_put(qp_in, f); |
224 | return qp; | |
225 | } | |
226 | } | |
227 | #endif | |
228 | qp = qp_in; | |
b2fd5321 | 229 | if (!mod_timer(&qp->timer, jiffies + nf->timeout)) |
2588fe1d PE |
230 | atomic_inc(&qp->refcnt); |
231 | ||
232 | atomic_inc(&qp->refcnt); | |
233 | hlist_add_head(&qp->list, &f->hash[hash]); | |
3140c25c | 234 | list_add_tail(&qp->lru_list, &nf->lru_list); |
e5a2bb84 | 235 | nf->nqueues++; |
2588fe1d PE |
236 | write_unlock(&f->lock); |
237 | return qp; | |
238 | } | |
e521db9d | 239 | |
ac18e750 PE |
240 | static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf, |
241 | struct inet_frags *f, void *arg) | |
e521db9d PE |
242 | { |
243 | struct inet_frag_queue *q; | |
244 | ||
245 | q = kzalloc(f->qsize, GFP_ATOMIC); | |
246 | if (q == NULL) | |
247 | return NULL; | |
248 | ||
54db0cc2 | 249 | q->net = nf; |
c6fda282 | 250 | f->constructor(q, arg); |
d433673e JDB |
251 | add_frag_mem_limit(q, f->qsize); |
252 | ||
e521db9d PE |
253 | setup_timer(&q->timer, f->frag_expire, (unsigned long)q); |
254 | spin_lock_init(&q->lock); | |
255 | atomic_set(&q->refcnt, 1); | |
256 | ||
257 | return q; | |
258 | } | |
c6fda282 | 259 | |
ac18e750 | 260 | static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf, |
9a375803 | 261 | struct inet_frags *f, void *arg) |
c6fda282 PE |
262 | { |
263 | struct inet_frag_queue *q; | |
264 | ||
ac18e750 | 265 | q = inet_frag_alloc(nf, f, arg); |
c6fda282 PE |
266 | if (q == NULL) |
267 | return NULL; | |
268 | ||
9a375803 | 269 | return inet_frag_intern(nf, q, f, arg); |
c6fda282 | 270 | } |
abd6523d | 271 | |
ac18e750 PE |
272 | struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, |
273 | struct inet_frags *f, void *key, unsigned int hash) | |
56bca31f | 274 | __releases(&f->lock) |
abd6523d PE |
275 | { |
276 | struct inet_frag_queue *q; | |
277 | struct hlist_node *n; | |
278 | ||
abd6523d | 279 | hlist_for_each_entry(q, n, &f->hash[hash], list) { |
ac18e750 | 280 | if (q->net == nf && f->match(q, key)) { |
abd6523d PE |
281 | atomic_inc(&q->refcnt); |
282 | read_unlock(&f->lock); | |
283 | return q; | |
284 | } | |
285 | } | |
286 | read_unlock(&f->lock); | |
287 | ||
9a375803 | 288 | return inet_frag_create(nf, f, key); |
abd6523d PE |
289 | } |
290 | EXPORT_SYMBOL(inet_frag_find); |