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> | |
7eb95156 PE |
22 | |
23 | #include <net/inet_frag.h> | |
24 | ||
321a3a99 PE |
25 | static void inet_frag_secret_rebuild(unsigned long dummy) |
26 | { | |
27 | struct inet_frags *f = (struct inet_frags *)dummy; | |
28 | unsigned long now = jiffies; | |
29 | int i; | |
30 | ||
31 | write_lock(&f->lock); | |
32 | get_random_bytes(&f->rnd, sizeof(u32)); | |
33 | for (i = 0; i < INETFRAGS_HASHSZ; i++) { | |
34 | struct inet_frag_queue *q; | |
35 | struct hlist_node *p, *n; | |
36 | ||
37 | hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) { | |
38 | unsigned int hval = f->hashfn(q); | |
39 | ||
40 | if (hval != i) { | |
41 | hlist_del(&q->list); | |
42 | ||
43 | /* Relink to new hash chain. */ | |
44 | hlist_add_head(&q->list, &f->hash[hval]); | |
45 | } | |
46 | } | |
47 | } | |
48 | write_unlock(&f->lock); | |
49 | ||
3b4bc4a2 | 50 | mod_timer(&f->secret_timer, now + f->secret_interval); |
321a3a99 PE |
51 | } |
52 | ||
7eb95156 PE |
53 | void inet_frags_init(struct inet_frags *f) |
54 | { | |
55 | int i; | |
56 | ||
57 | for (i = 0; i < INETFRAGS_HASHSZ; i++) | |
58 | INIT_HLIST_HEAD(&f->hash[i]); | |
59 | ||
7eb95156 PE |
60 | rwlock_init(&f->lock); |
61 | ||
62 | f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^ | |
63 | (jiffies ^ (jiffies >> 6))); | |
64 | ||
b24b8a24 PE |
65 | setup_timer(&f->secret_timer, inet_frag_secret_rebuild, |
66 | (unsigned long)f); | |
3b4bc4a2 | 67 | f->secret_timer.expires = jiffies + f->secret_interval; |
321a3a99 | 68 | add_timer(&f->secret_timer); |
7eb95156 PE |
69 | } |
70 | EXPORT_SYMBOL(inet_frags_init); | |
71 | ||
e5a2bb84 PE |
72 | void inet_frags_init_net(struct netns_frags *nf) |
73 | { | |
74 | nf->nqueues = 0; | |
6ddc0822 | 75 | atomic_set(&nf->mem, 0); |
3140c25c | 76 | INIT_LIST_HEAD(&nf->lru_list); |
e5a2bb84 PE |
77 | } |
78 | EXPORT_SYMBOL(inet_frags_init_net); | |
79 | ||
7eb95156 PE |
80 | void inet_frags_fini(struct inet_frags *f) |
81 | { | |
321a3a99 | 82 | del_timer(&f->secret_timer); |
7eb95156 PE |
83 | } |
84 | EXPORT_SYMBOL(inet_frags_fini); | |
277e650d | 85 | |
81566e83 PE |
86 | void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f) |
87 | { | |
88 | nf->low_thresh = 0; | |
89 | inet_frag_evictor(nf, f); | |
90 | } | |
91 | EXPORT_SYMBOL(inet_frags_exit_net); | |
92 | ||
277e650d PE |
93 | static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f) |
94 | { | |
95 | write_lock(&f->lock); | |
96 | hlist_del(&fq->list); | |
97 | list_del(&fq->lru_list); | |
e5a2bb84 | 98 | fq->net->nqueues--; |
277e650d PE |
99 | write_unlock(&f->lock); |
100 | } | |
101 | ||
102 | void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f) | |
103 | { | |
104 | if (del_timer(&fq->timer)) | |
105 | atomic_dec(&fq->refcnt); | |
106 | ||
107 | if (!(fq->last_in & COMPLETE)) { | |
108 | fq_unlink(fq, f); | |
109 | atomic_dec(&fq->refcnt); | |
110 | fq->last_in |= COMPLETE; | |
111 | } | |
112 | } | |
113 | ||
114 | EXPORT_SYMBOL(inet_frag_kill); | |
1e4b8287 | 115 | |
6ddc0822 PE |
116 | static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f, |
117 | struct sk_buff *skb, int *work) | |
1e4b8287 PE |
118 | { |
119 | if (work) | |
120 | *work -= skb->truesize; | |
121 | ||
6ddc0822 | 122 | atomic_sub(skb->truesize, &nf->mem); |
1e4b8287 PE |
123 | if (f->skb_free) |
124 | f->skb_free(skb); | |
125 | kfree_skb(skb); | |
126 | } | |
127 | ||
128 | void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f, | |
129 | int *work) | |
130 | { | |
131 | struct sk_buff *fp; | |
6ddc0822 | 132 | struct netns_frags *nf; |
1e4b8287 PE |
133 | |
134 | BUG_TRAP(q->last_in & COMPLETE); | |
135 | BUG_TRAP(del_timer(&q->timer) == 0); | |
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 | ||
6ddc0822 | 143 | frag_kfree_skb(nf, f, fp, work); |
1e4b8287 PE |
144 | fp = xp; |
145 | } | |
146 | ||
147 | if (work) | |
148 | *work -= f->qsize; | |
6ddc0822 | 149 | atomic_sub(f->qsize, &nf->mem); |
1e4b8287 | 150 | |
c9547709 PE |
151 | if (f->destructor) |
152 | f->destructor(q); | |
153 | kfree(q); | |
1e4b8287 PE |
154 | |
155 | } | |
156 | EXPORT_SYMBOL(inet_frag_destroy); | |
8e7999c4 | 157 | |
6ddc0822 | 158 | int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f) |
8e7999c4 PE |
159 | { |
160 | struct inet_frag_queue *q; | |
161 | int work, evicted = 0; | |
162 | ||
e31e0bdc | 163 | work = atomic_read(&nf->mem) - nf->low_thresh; |
8e7999c4 PE |
164 | while (work > 0) { |
165 | read_lock(&f->lock); | |
3140c25c | 166 | if (list_empty(&nf->lru_list)) { |
8e7999c4 PE |
167 | read_unlock(&f->lock); |
168 | break; | |
169 | } | |
170 | ||
3140c25c | 171 | q = list_first_entry(&nf->lru_list, |
8e7999c4 PE |
172 | struct inet_frag_queue, lru_list); |
173 | atomic_inc(&q->refcnt); | |
174 | read_unlock(&f->lock); | |
175 | ||
176 | spin_lock(&q->lock); | |
177 | if (!(q->last_in & COMPLETE)) | |
178 | inet_frag_kill(q, f); | |
179 | spin_unlock(&q->lock); | |
180 | ||
181 | if (atomic_dec_and_test(&q->refcnt)) | |
182 | inet_frag_destroy(q, f, &work); | |
183 | evicted++; | |
184 | } | |
185 | ||
186 | return evicted; | |
187 | } | |
188 | EXPORT_SYMBOL(inet_frag_evictor); | |
2588fe1d | 189 | |
ac18e750 PE |
190 | static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf, |
191 | struct inet_frag_queue *qp_in, struct inet_frags *f, | |
192 | unsigned int hash, void *arg) | |
2588fe1d PE |
193 | { |
194 | struct inet_frag_queue *qp; | |
195 | #ifdef CONFIG_SMP | |
196 | struct hlist_node *n; | |
197 | #endif | |
198 | ||
199 | write_lock(&f->lock); | |
200 | #ifdef CONFIG_SMP | |
201 | /* With SMP race we have to recheck hash table, because | |
202 | * such entry could be created on other cpu, while we | |
203 | * promoted read lock to write lock. | |
204 | */ | |
205 | hlist_for_each_entry(qp, n, &f->hash[hash], list) { | |
ac18e750 | 206 | if (qp->net == nf && f->match(qp, arg)) { |
2588fe1d PE |
207 | atomic_inc(&qp->refcnt); |
208 | write_unlock(&f->lock); | |
209 | qp_in->last_in |= COMPLETE; | |
210 | inet_frag_put(qp_in, f); | |
211 | return qp; | |
212 | } | |
213 | } | |
214 | #endif | |
215 | qp = qp_in; | |
b2fd5321 | 216 | if (!mod_timer(&qp->timer, jiffies + nf->timeout)) |
2588fe1d PE |
217 | atomic_inc(&qp->refcnt); |
218 | ||
219 | atomic_inc(&qp->refcnt); | |
220 | hlist_add_head(&qp->list, &f->hash[hash]); | |
3140c25c | 221 | list_add_tail(&qp->lru_list, &nf->lru_list); |
e5a2bb84 | 222 | nf->nqueues++; |
2588fe1d PE |
223 | write_unlock(&f->lock); |
224 | return qp; | |
225 | } | |
e521db9d | 226 | |
ac18e750 PE |
227 | static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf, |
228 | struct inet_frags *f, void *arg) | |
e521db9d PE |
229 | { |
230 | struct inet_frag_queue *q; | |
231 | ||
232 | q = kzalloc(f->qsize, GFP_ATOMIC); | |
233 | if (q == NULL) | |
234 | return NULL; | |
235 | ||
c6fda282 | 236 | f->constructor(q, arg); |
6ddc0822 | 237 | atomic_add(f->qsize, &nf->mem); |
e521db9d PE |
238 | setup_timer(&q->timer, f->frag_expire, (unsigned long)q); |
239 | spin_lock_init(&q->lock); | |
240 | atomic_set(&q->refcnt, 1); | |
ac18e750 | 241 | q->net = nf; |
e521db9d PE |
242 | |
243 | return q; | |
244 | } | |
c6fda282 | 245 | |
ac18e750 PE |
246 | static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf, |
247 | struct inet_frags *f, void *arg, unsigned int hash) | |
c6fda282 PE |
248 | { |
249 | struct inet_frag_queue *q; | |
250 | ||
ac18e750 | 251 | q = inet_frag_alloc(nf, f, arg); |
c6fda282 PE |
252 | if (q == NULL) |
253 | return NULL; | |
254 | ||
ac18e750 | 255 | return inet_frag_intern(nf, q, f, hash, arg); |
c6fda282 | 256 | } |
abd6523d | 257 | |
ac18e750 PE |
258 | struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, |
259 | struct inet_frags *f, void *key, unsigned int hash) | |
abd6523d PE |
260 | { |
261 | struct inet_frag_queue *q; | |
262 | struct hlist_node *n; | |
263 | ||
264 | read_lock(&f->lock); | |
265 | hlist_for_each_entry(q, n, &f->hash[hash], list) { | |
ac18e750 | 266 | if (q->net == nf && f->match(q, key)) { |
abd6523d PE |
267 | atomic_inc(&q->refcnt); |
268 | read_unlock(&f->lock); | |
269 | return q; | |
270 | } | |
271 | } | |
272 | read_unlock(&f->lock); | |
273 | ||
ac18e750 | 274 | return inet_frag_create(nf, f, key, hash); |
abd6523d PE |
275 | } |
276 | EXPORT_SYMBOL(inet_frag_find); |