Release 4.18 net/ipv4/inet_fragment.c

/*
 * inet fragments management
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 *              Authors:        Pavel Emelyanov <xemul@openvz.org>
 *                              Started as consolidation of ipv4/ip_fragment.c,
 *                              ipv6/reassembly. and ipv6 nf conntrack reassembly
 */

#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>

#include <net/sock.h>
#include <net/inet_frag.h>
#include <net/inet_ecn.h>

/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
 * Value : 0xff if frame should be dropped.
 *         0 or INET_ECN_CE value, to be ORed in to final iph->tos field
 */

const u8 ip_frag_ecn_table[16] = {
	/* at least one fragment had CE, and others ECT_0 or ECT_1 */
	[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0]			= INET_ECN_CE,
	[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1]			= INET_ECN_CE,
	[IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1]	= INET_ECN_CE,

	/* invalid combinations : drop frame */
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
	[IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
};
EXPORT_SYMBOL(ip_frag_ecn_table);



int inet_frags_init(struct inet_frags *f)
{
	f->frags_cachep = kmem_cache_create(f->frags_cache_name, f->qsize, 0, 0,
					    NULL);
	if (!f->frags_cachep)
		return -ENOMEM;

	return 0;
}
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Florian Westphal
18
40.00%
2
66.67%
Total
45
100.00%
3
100.00%

EXPORT_SYMBOL(inet_frags_init);



void inet_frags_fini(struct inet_frags *f)
{
	/* We must wait that all inet_frag_destroy_rcu() have completed. */
	rcu_barrier();

	kmem_cache_destroy(f->frags_cachep);
	f->frags_cachep = NULL;
}
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Eric Dumazet
12
44.44%
1
33.33%
Pavel Emelyanov
11
40.74%
1
33.33%
Florian Westphal
4
14.81%
1
33.33%
Total
27
100.00%
3
100.00%

EXPORT_SYMBOL(inet_frags_fini);



static void inet_frags_free_cb(void *ptr, void *arg)
{
	struct inet_frag_queue *fq = ptr;

	/* If we can not cancel the timer, it means this frag_queue
         * is already disappearing, we have nothing to do.
         * Otherwise, we own a refcount until the end of this function.
         */
	if (!del_timer(&fq->timer))
		return;

	spin_lock_bh(&fq->lock);
	if (!(fq->flags & INET_FRAG_COMPLETE)) {
		fq->flags |= INET_FRAG_COMPLETE;
		refcount_dec(&fq->refcnt);
	}
	spin_unlock_bh(&fq->lock);

	inet_frag_put(fq);
}

Contributors
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CommitProp
Eric Dumazet
49
59.76%
1
20.00%
Pavel Emelyanov
16
19.51%
1
20.00%
Florian Westphal
16
19.51%
2
40.00%
Jesper Dangaard Brouer
1
1.22%
1
20.00%
Total
82
100.00%
5
100.00%



void inet_frags_exit_net(struct netns_frags *nf)
{
	nf->high_thresh = 0; /* prevent creation of new frags */

	rhashtable_free_and_destroy(&nf->rhashtable, inet_frags_free_cb, NULL);
}
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Eric Dumazet
19
65.52%
1
25.00%
Florian Westphal
9
31.03%
2
50.00%
Paolo Abeni
1
3.45%
1
25.00%
Total
29
100.00%
4
100.00%

EXPORT_SYMBOL(inet_frags_exit_net);



void inet_frag_kill(struct inet_frag_queue *fq)
{
	if (del_timer(&fq->timer))
		refcount_dec(&fq->refcnt);

	if (!(fq->flags & INET_FRAG_COMPLETE)) {
		struct netns_frags *nf = fq->net;

		fq->flags |= INET_FRAG_COMPLETE;
		rhashtable_remove_fast(&nf->rhashtable, &fq->node, nf->f->rhash_params);
		refcount_dec(&fq->refcnt);
	}
}
Contributors
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CommitProp
Eric Dumazet
45
54.22%
2
25.00%
Florian Westphal
21
25.30%
3
37.50%
Kirill Tkhai
7
8.43%
1
12.50%
Pavel Emelyanov
6
7.23%
1
12.50%
Jesper Dangaard Brouer
4
4.82%
1
12.50%
Total
83
100.00%
8
100.00%

EXPORT_SYMBOL(inet_frag_kill);



static void inet_frag_destroy_rcu(struct rcu_head *head)
{
	struct inet_frag_queue *q = container_of(head, struct inet_frag_queue,
						 rcu);
	struct inet_frags *f = q->net->f;

	if (f->destructor)
		f->destructor(q);
	kmem_cache_free(f->frags_cachep, q);
}

Contributors
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Eric Dumazet
38
64.41%
1
50.00%
Pavel Emelyanov
21
35.59%
1
50.00%
Total
59
100.00%
2
100.00%



void inet_frag_destroy(struct inet_frag_queue *q)
{
	struct sk_buff *fp;
	struct netns_frags *nf;
	unsigned int sum, sum_truesize = 0;
	struct inet_frags *f;

	WARN_ON(!(q->flags & INET_FRAG_COMPLETE));
	WARN_ON(del_timer(&q->timer) != 0);

	/* Release all fragment data. */
	fp = q->fragments;
	nf = q->net;
	f = nf->f;
	while (fp) {
		struct sk_buff *xp = fp->next;

		sum_truesize += fp->truesize;
		kfree_skb(fp);
		fp = xp;
	}
	sum = sum_truesize + f->qsize;

	call_rcu(&q->rcu, inet_frag_destroy_rcu);

	sub_frag_mem_limit(nf, sum);
}
Contributors
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CommitProp
Pavel Emelyanov
80
60.61%
3
33.33%
Eric Dumazet
30
22.73%
2
22.22%
Jesper Dangaard Brouer
14
10.61%
1
11.11%
Ilpo Järvinen
6
4.55%
1
11.11%
Nikolay Aleksandrov
1
0.76%
1
11.11%
Joe Perches
1
0.76%
1
11.11%
Total
132
100.00%
9
100.00%

EXPORT_SYMBOL(inet_frag_destroy);



static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
					       struct inet_frags *f,
					       void *arg)
{
	struct inet_frag_queue *q;

	q = kmem_cache_zalloc(f->frags_cachep, GFP_ATOMIC);
	if (!q)
		return NULL;

	q->net = nf;
	f->constructor(q, arg);
	add_frag_mem_limit(nf, f->qsize);

	timer_setup(&q->timer, f->frag_expire, 0);
	spin_lock_init(&q->lock);
	refcount_set(&q->refcnt, 3);

	return q;
}

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Pavel Emelyanov
89
84.76%
3
27.27%
Gao Feng
6
5.71%
1
9.09%
Nikolay Aleksandrov
2
1.90%
1
9.09%
Kees Cook
2
1.90%
1
9.09%
Jesper Dangaard Brouer
2
1.90%
1
9.09%
Elena Reshetova
1
0.95%
1
9.09%
Ian Morris
1
0.95%
1
9.09%
Florian Westphal
1
0.95%
1
9.09%
Eric Dumazet
1
0.95%
1
9.09%
Total
105
100.00%
11
100.00%



static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
						void *arg)
{
	struct inet_frags *f = nf->f;
	struct inet_frag_queue *q;
	int err;

	q = inet_frag_alloc(nf, f, arg);
	if (!q)
		return NULL;

	mod_timer(&q->timer, jiffies + nf->timeout);

	err = rhashtable_insert_fast(&nf->rhashtable, &q->node,
				     f->rhash_params);
	if (err < 0) {
		q->flags |= INET_FRAG_COMPLETE;
		inet_frag_kill(q);
		inet_frag_destroy(q);
		return NULL;
	}
	return q;
}

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Eric Dumazet
67
57.76%
1
20.00%
Pavel Emelyanov
48
41.38%
3
60.00%
Ian Morris
1
0.86%
1
20.00%
Total
116
100.00%
5
100.00%

/* TODO : call from rcu_read_lock() and no longer use refcount_inc_not_zero() */


struct inet_frag_queue *inet_frag_find(struct netns_frags *nf, void *key)
{
	struct inet_frag_queue *fq;

	if (!nf->high_thresh || frag_mem_limit(nf) > nf->high_thresh)
		return NULL;

	rcu_read_lock();

	fq = rhashtable_lookup(&nf->rhashtable, key, nf->f->rhash_params);
	if (fq) {
		if (!refcount_inc_not_zero(&fq->refcnt))
			fq = NULL;
		rcu_read_unlock();
		return fq;
	}
	rcu_read_unlock();

	return inet_frag_create(nf, key);
}
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47
47.47%
2
28.57%
Pavel Emelyanov
44
44.44%
2
28.57%
Jesper Dangaard Brouer
6
6.06%
1
14.29%
Hannes Frederic Sowa
1
1.01%
1
14.29%
Florian Westphal
1
1.01%
1
14.29%
Total
99
100.00%
7
100.00%

EXPORT_SYMBOL(inet_frag_find);
Overall Contributors
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Eric Dumazet
355
37.21%
3
8.82%
Pavel Emelyanov
351
36.79%
10
29.41%
Hannes Frederic Sowa
116
12.16%
2
5.88%
Florian Westphal
70
7.34%
6
17.65%
Jesper Dangaard Brouer
30
3.14%
2
5.88%
Kirill Tkhai
7
0.73%
1
2.94%
Gao Feng
6
0.63%
1
2.94%
Ilpo Järvinen
6
0.63%
1
2.94%
Tejun Heo
3
0.31%
1
2.94%
Nikolay Aleksandrov
3
0.31%
2
5.88%
Kees Cook
2
0.21%
1
2.94%
Ian Morris
2
0.21%
1
2.94%
Elena Reshetova
1
0.10%
1
2.94%
Paolo Abeni
1
0.10%
1
2.94%
Joe Perches
1
0.10%
1
2.94%
Total
954
100.00%
34
100.00%
Directory: net/ipv4

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