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> |
0eb71a9d | 23 | #include <linux/rhashtable.h> |
7eb95156 | 24 | |
5a3da1fe | 25 | #include <net/sock.h> |
7eb95156 | 26 | #include <net/inet_frag.h> |
be991971 HFS |
27 | #include <net/inet_ecn.h> |
28 | ||
29 | /* Given the OR values of all fragments, apply RFC 3168 5.3 requirements | |
30 | * Value : 0xff if frame should be dropped. | |
31 | * 0 or INET_ECN_CE value, to be ORed in to final iph->tos field | |
32 | */ | |
33 | const u8 ip_frag_ecn_table[16] = { | |
34 | /* at least one fragment had CE, and others ECT_0 or ECT_1 */ | |
35 | [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = INET_ECN_CE, | |
36 | [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = INET_ECN_CE, | |
37 | [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = INET_ECN_CE, | |
38 | ||
39 | /* invalid combinations : drop frame */ | |
40 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff, | |
41 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff, | |
42 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff, | |
43 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, | |
44 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff, | |
45 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff, | |
46 | [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff, | |
47 | }; | |
48 | EXPORT_SYMBOL(ip_frag_ecn_table); | |
7eb95156 | 49 | |
d4ad4d22 | 50 | int inet_frags_init(struct inet_frags *f) |
7eb95156 | 51 | { |
d4ad4d22 NA |
52 | f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0, |
53 | NULL); | |
54 | if (!f->frags_cachep) | |
55 | return -ENOMEM; | |
56 | ||
57 | return 0; | |
7eb95156 PE |
58 | } |
59 | EXPORT_SYMBOL(inet_frags_init); | |
60 | ||
61 | void inet_frags_fini(struct inet_frags *f) | |
62 | { | |
648700f7 ED |
63 | /* We must wait that all inet_frag_destroy_rcu() have completed. */ |
64 | rcu_barrier(); | |
65 | ||
d4ad4d22 | 66 | kmem_cache_destroy(f->frags_cachep); |
648700f7 | 67 | f->frags_cachep = NULL; |
7eb95156 PE |
68 | } |
69 | EXPORT_SYMBOL(inet_frags_fini); | |
277e650d | 70 | |
648700f7 | 71 | static void inet_frags_free_cb(void *ptr, void *arg) |
277e650d | 72 | { |
648700f7 | 73 | struct inet_frag_queue *fq = ptr; |
ab1c724f | 74 | |
648700f7 ED |
75 | /* If we can not cancel the timer, it means this frag_queue |
76 | * is already disappearing, we have nothing to do. | |
77 | * Otherwise, we own a refcount until the end of this function. | |
78 | */ | |
79 | if (!del_timer(&fq->timer)) | |
80 | return; | |
19952cc4 | 81 | |
648700f7 ED |
82 | spin_lock_bh(&fq->lock); |
83 | if (!(fq->flags & INET_FRAG_COMPLETE)) { | |
84 | fq->flags |= INET_FRAG_COMPLETE; | |
85 | refcount_dec(&fq->refcnt); | |
ab1c724f | 86 | } |
648700f7 | 87 | spin_unlock_bh(&fq->lock); |
ab1c724f | 88 | |
648700f7 | 89 | inet_frag_put(fq); |
ab1c724f FW |
90 | } |
91 | ||
648700f7 | 92 | void inet_frags_exit_net(struct netns_frags *nf) |
ab1c724f | 93 | { |
f6f2a4a2 | 94 | nf->high_thresh = 0; /* prevent creation of new frags */ |
ab1c724f | 95 | |
648700f7 | 96 | rhashtable_free_and_destroy(&nf->rhashtable, inet_frags_free_cb, NULL); |
277e650d | 97 | } |
648700f7 | 98 | EXPORT_SYMBOL(inet_frags_exit_net); |
277e650d | 99 | |
093ba729 | 100 | void inet_frag_kill(struct inet_frag_queue *fq) |
277e650d PE |
101 | { |
102 | if (del_timer(&fq->timer)) | |
edcb6918 | 103 | refcount_dec(&fq->refcnt); |
277e650d | 104 | |
06aa8b8a | 105 | if (!(fq->flags & INET_FRAG_COMPLETE)) { |
648700f7 ED |
106 | struct netns_frags *nf = fq->net; |
107 | ||
108 | fq->flags |= INET_FRAG_COMPLETE; | |
109 | rhashtable_remove_fast(&nf->rhashtable, &fq->node, nf->f->rhash_params); | |
edcb6918 | 110 | refcount_dec(&fq->refcnt); |
277e650d PE |
111 | } |
112 | } | |
277e650d | 113 | EXPORT_SYMBOL(inet_frag_kill); |
1e4b8287 | 114 | |
648700f7 ED |
115 | static void inet_frag_destroy_rcu(struct rcu_head *head) |
116 | { | |
117 | struct inet_frag_queue *q = container_of(head, struct inet_frag_queue, | |
118 | rcu); | |
119 | struct inet_frags *f = q->net->f; | |
120 | ||
121 | if (f->destructor) | |
122 | f->destructor(q); | |
123 | kmem_cache_free(f->frags_cachep, q); | |
124 | } | |
125 | ||
093ba729 | 126 | void inet_frag_destroy(struct inet_frag_queue *q) |
1e4b8287 PE |
127 | { |
128 | struct sk_buff *fp; | |
6ddc0822 | 129 | struct netns_frags *nf; |
d433673e | 130 | unsigned int sum, sum_truesize = 0; |
093ba729 | 131 | struct inet_frags *f; |
1e4b8287 | 132 | |
06aa8b8a | 133 | WARN_ON(!(q->flags & INET_FRAG_COMPLETE)); |
547b792c | 134 | WARN_ON(del_timer(&q->timer) != 0); |
1e4b8287 PE |
135 | |
136 | /* Release all fragment data. */ | |
137 | fp = q->fragments; | |
6ddc0822 | 138 | nf = q->net; |
093ba729 | 139 | f = nf->f; |
fa0f5273 PO |
140 | if (fp) { |
141 | do { | |
142 | struct sk_buff *xp = fp->next; | |
143 | ||
144 | sum_truesize += fp->truesize; | |
145 | kfree_skb(fp); | |
146 | fp = xp; | |
147 | } while (fp); | |
148 | } else { | |
a4fd284a | 149 | sum_truesize = inet_frag_rbtree_purge(&q->rb_fragments); |
1e4b8287 | 150 | } |
d433673e | 151 | sum = sum_truesize + f->qsize; |
1e4b8287 | 152 | |
648700f7 | 153 | call_rcu(&q->rcu, inet_frag_destroy_rcu); |
5719b296 FW |
154 | |
155 | sub_frag_mem_limit(nf, sum); | |
1e4b8287 PE |
156 | } |
157 | EXPORT_SYMBOL(inet_frag_destroy); | |
8e7999c4 | 158 | |
ac18e750 | 159 | static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf, |
f926e236 NA |
160 | struct inet_frags *f, |
161 | void *arg) | |
e521db9d PE |
162 | { |
163 | struct inet_frag_queue *q; | |
164 | ||
d4ad4d22 | 165 | q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC); |
51456b29 | 166 | if (!q) |
e521db9d PE |
167 | return NULL; |
168 | ||
54db0cc2 | 169 | q->net = nf; |
c6fda282 | 170 | f->constructor(q, arg); |
0e60d245 | 171 | add_frag_mem_limit(nf, f->qsize); |
d433673e | 172 | |
78802011 | 173 | timer_setup(&q->timer, f->frag_expire, 0); |
e521db9d | 174 | spin_lock_init(&q->lock); |
648700f7 | 175 | refcount_set(&q->refcnt, 3); |
e521db9d PE |
176 | |
177 | return q; | |
178 | } | |
c6fda282 | 179 | |
ac18e750 | 180 | static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf, |
f926e236 | 181 | void *arg) |
c6fda282 | 182 | { |
648700f7 | 183 | struct inet_frags *f = nf->f; |
c6fda282 | 184 | struct inet_frag_queue *q; |
648700f7 | 185 | int err; |
c6fda282 | 186 | |
ac18e750 | 187 | q = inet_frag_alloc(nf, f, arg); |
51456b29 | 188 | if (!q) |
c6fda282 PE |
189 | return NULL; |
190 | ||
648700f7 ED |
191 | mod_timer(&q->timer, jiffies + nf->timeout); |
192 | ||
193 | err = rhashtable_insert_fast(&nf->rhashtable, &q->node, | |
194 | f->rhash_params); | |
195 | if (err < 0) { | |
196 | q->flags |= INET_FRAG_COMPLETE; | |
197 | inet_frag_kill(q); | |
198 | inet_frag_destroy(q); | |
199 | return NULL; | |
200 | } | |
201 | return q; | |
c6fda282 | 202 | } |
abd6523d | 203 | |
648700f7 ED |
204 | /* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */ |
205 | struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key) | |
abd6523d | 206 | { |
648700f7 | 207 | struct inet_frag_queue *fq; |
abd6523d | 208 | |
56e2c94f ED |
209 | if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh) |
210 | return NULL; | |
211 | ||
648700f7 | 212 | rcu_read_lock(); |
e3a57d18 | 213 | |
648700f7 ED |
214 | fq = rhashtable_lookup(&nf->rhashtable, key, nf->f->rhash_params); |
215 | if (fq) { | |
216 | if (!refcount_inc_not_zero(&fq->refcnt)) | |
217 | fq = NULL; | |
218 | rcu_read_unlock(); | |
219 | return fq; | |
e3a57d18 | 220 | } |
648700f7 | 221 | rcu_read_unlock(); |
e3a57d18 | 222 | |
648700f7 | 223 | return inet_frag_create(nf, key); |
abd6523d PE |
224 | } |
225 | EXPORT_SYMBOL(inet_frag_find); |