[mirror_ovs.git] / datapath / linux / compat / 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
 */

#ifndef HAVE_CORRECT_MRU_HANDLING

#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>

#ifdef HAVE_INET_FRAGS_WITH_FRAGS_WORK
static bool inet_fragq_should_evict(const struct inet_frag_queue *q)
{
	return q->net->low_thresh == 0 ||
	       frag_mem_limit(q->net) >= q->net->low_thresh;
}

static unsigned int
inet_evict_bucket(struct inet_frags *f, struct inet_frag_bucket *hb)
{
	struct inet_frag_queue *fq;
	struct hlist_node *n;
	unsigned int evicted = 0;
	HLIST_HEAD(expired);

	spin_lock(&hb->chain_lock);

	hlist_for_each_entry_safe(fq, n, &hb->chain, list) {
		if (!inet_fragq_should_evict(fq))
			continue;

		if (!del_timer(&fq->timer))
			continue;

#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
		hlist_add_head(&fq->list_evictor, &expired);
#else
		hlist_del(&fq->list);
		hlist_add_head(&fq->list, &expired);
#endif
		++evicted;
	}

	spin_unlock(&hb->chain_lock);

#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
	hlist_for_each_entry_safe(fq, n, &expired, list_evictor)
#else
	hlist_for_each_entry_safe(fq, n, &expired, list)
#endif
		f->frag_expire((unsigned long) fq);

	return evicted;
}

void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
{
	int thresh = nf->low_thresh;
	unsigned int seq;
	int i;

	nf->low_thresh = 0;

evict_again:
	local_bh_disable();
	seq = read_seqbegin(&f->rnd_seqlock);

	for (i = 0; i < INETFRAGS_HASHSZ ; i++)
		inet_evict_bucket(f, &f->hash[i]);

	local_bh_enable();
	cond_resched();

	if (read_seqretry(&f->rnd_seqlock, seq) ||
	    percpu_counter_sum(&nf->mem))
		goto evict_again;

	nf->low_thresh = thresh;
}
#else /* HAVE_INET_FRAGS_WITH_FRAGS_WORK */
void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
{
	int thresh = nf->low_thresh;

	nf->low_thresh = 0;

	local_bh_disable();
	inet_frag_evictor(nf, f, true);
	local_bh_enable();

	nf->low_thresh = thresh;
}
#endif /* HAVE_INET_FRAGS_WITH_FRAGS_WORK */

#endif /* !HAVE_CORRECT_MRU_HANDLING */
Commit	Line	Data
595e069a JS	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
3cdc5697	14	#ifndef HAVE_CORRECT_MRU_HANDLING
595e069a JS	15
	16	#include <linux/list.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/module.h>
	19	#include <linux/timer.h>
	20	#include <linux/mm.h>
	21	#include <linux/random.h>
	22	#include <linux/skbuff.h>
	23	#include <linux/rtnetlink.h>
	24	#include <linux/slab.h>
	25
	26	#include <net/sock.h>
	27	#include <net/inet_frag.h>
	28	#include <net/inet_ecn.h>
	29
91408ae0	30	#ifdef HAVE_INET_FRAGS_WITH_FRAGS_WORK
595e069a JS	31	static bool inet_fragq_should_evict(const struct inet_frag_queue *q)
	32	{
	33	return q->net->low_thresh == 0 \|\|
	34	frag_mem_limit(q->net) >= q->net->low_thresh;
	35	}
	36
	37	static unsigned int
	38	inet_evict_bucket(struct inet_frags f, struct inet_frag_bucket hb)
	39	{
595e069a JS	40	struct inet_frag_queue *fq;
	41	struct hlist_node *n;
	42	unsigned int evicted = 0;
	43	HLIST_HEAD(expired);
	44
	45	spin_lock(&hb->chain_lock);
	46
	47	hlist_for_each_entry_safe(fq, n, &hb->chain, list) {
	48	if (!inet_fragq_should_evict(fq))
	49	continue;
	50
	51	if (!del_timer(&fq->timer))
	52	continue;
	53
e0d45da3 JS	54	#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
	55	hlist_add_head(&fq->list_evictor, &expired);
	56	#else
ccd0a13b JS	57	hlist_del(&fq->list);
ccd0a13b JS	58	hlist_add_head(&fq->list, &expired);
595e069a JS	59	#endif
	60	++evicted;
	61	}
	62
	63	spin_unlock(&hb->chain_lock);
	64
e0d45da3	65	#ifdef HAVE_INET_FRAG_QUEUE_WITH_LIST_EVICTOR
595e069a	66	hlist_for_each_entry_safe(fq, n, &expired, list_evictor)
e0d45da3	67	#else
ccd0a13b	68	hlist_for_each_entry_safe(fq, n, &expired, list)
595e069a	69	#endif
ccd0a13b	70	f->frag_expire((unsigned long) fq);
595e069a JS	71
	72	return evicted;
	73	}
	74
595e069a JS	75	void inet_frags_exit_net(struct netns_frags nf, struct inet_frags f)
595e069a JS	76	{
ccd0a13b	77	int thresh = nf->low_thresh;
595e069a	78	unsigned int seq;
ccd0a13b JS	79	int i;
	80
	81	nf->low_thresh = 0;
595e069a JS	82
	83	evict_again:
	84	local_bh_disable();
	85	seq = read_seqbegin(&f->rnd_seqlock);
	86
ccd0a13b JS	87	for (i = 0; i < INETFRAGS_HASHSZ ; i++)
ccd0a13b JS	88	inet_evict_bucket(f, &f->hash[i]);
595e069a JS	89
	90	local_bh_enable();
	91	cond_resched();
	92
	93	if (read_seqretry(&f->rnd_seqlock, seq) \|\|
	94	percpu_counter_sum(&nf->mem))
	95	goto evict_again;
595e069a	96
ccd0a13b	97	nf->low_thresh = thresh;
595e069a	98	}
ccd0a13b JS	99	#else /* HAVE_INET_FRAGS_WITH_FRAGS_WORK */
ccd0a13b JS	100	void inet_frags_exit_net(struct netns_frags nf, struct inet_frags f)
595e069a	101	{
ccd0a13b	102	int thresh = nf->low_thresh;
595e069a	103
ccd0a13b	104	nf->low_thresh = 0;
595e069a	105
ccd0a13b JS	106	local_bh_disable();
	107	inet_frag_evictor(nf, f, true);
	108	local_bh_enable();
595e069a	109
ccd0a13b	110	nf->low_thresh = thresh;
595e069a	111	}
ccd0a13b	112	#endif /* HAVE_INET_FRAGS_WITH_FRAGS_WORK */
595e069a	113
3cdc5697	114	#endif /* !HAVE_CORRECT_MRU_HANDLING */