[mirror_ubuntu-artful-kernel.git] / net / netfilter / nf_conntrack_labels.c

/*
 * test/set flag bits stored in conntrack extension area.
 *
 * (C) 2013 Astaro GmbH & Co KG
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/export.h>
#include <linux/types.h>

#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_labels.h>

static spinlock_t nf_connlabels_lock;

int nf_connlabel_set(struct nf_conn *ct, u16 bit)
{
	struct nf_conn_labels *labels = nf_ct_labels_find(ct);

	if (!labels || BIT_WORD(bit) >= labels->words)
		return -ENOSPC;

	if (test_bit(bit, labels->bits))
		return 0;

	if (!test_and_set_bit(bit, labels->bits))
		nf_conntrack_event_cache(IPCT_LABEL, ct);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_connlabel_set);

static int replace_u32(u32 *address, u32 mask, u32 new)
{
	u32 old, tmp;

	do {
		old = *address;
		tmp = (old & mask) ^ new;
		if (old == tmp)
			return 0;
	} while (cmpxchg(address, old, tmp) != old);

	return 1;
}

int nf_connlabels_replace(struct nf_conn *ct,
			  const u32 *data,
			  const u32 *mask, unsigned int words32)
{
	struct nf_conn_labels *labels;
	unsigned int size, i;
	int changed = 0;
	u32 *dst;

	labels = nf_ct_labels_find(ct);
	if (!labels)
		return -ENOSPC;

	size = labels->words * sizeof(long);
	if (size < (words32 * sizeof(u32)))
		words32 = size / sizeof(u32);

	dst = (u32 *) labels->bits;
	for (i = 0; i < words32; i++)
		changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);

	size /= sizeof(u32);
	for (i = words32; i < size; i++) /* pad */
		replace_u32(&dst[i], 0, 0);

	if (changed)
		nf_conntrack_event_cache(IPCT_LABEL, ct);
	return 0;
}
EXPORT_SYMBOL_GPL(nf_connlabels_replace);

int nf_connlabels_get(struct net *net, unsigned int bits)
{
	size_t words;

	words = BIT_WORD(bits) + 1;
	if (words > NF_CT_LABELS_MAX_SIZE / sizeof(long))
		return -ERANGE;

	spin_lock(&nf_connlabels_lock);
	net->ct.labels_used++;
	if (words > net->ct.label_words)
		net->ct.label_words = words;
	spin_unlock(&nf_connlabels_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_connlabels_get);

void nf_connlabels_put(struct net *net)
{
	spin_lock(&nf_connlabels_lock);
	net->ct.labels_used--;
	if (net->ct.labels_used == 0)
		net->ct.label_words = 0;
	spin_unlock(&nf_connlabels_lock);
}
EXPORT_SYMBOL_GPL(nf_connlabels_put);

static struct nf_ct_ext_type labels_extend __read_mostly = {
	.len    = sizeof(struct nf_conn_labels),
	.align  = __alignof__(struct nf_conn_labels),
	.id     = NF_CT_EXT_LABELS,
};

int nf_conntrack_labels_init(void)
{
	BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);

	spin_lock_init(&nf_connlabels_lock);
	return nf_ct_extend_register(&labels_extend);
}

void nf_conntrack_labels_fini(void)
{
	nf_ct_extend_unregister(&labels_extend);
}
Commit	Line	Data
c539f017 FW	1	/*
	2	* test/set flag bits stored in conntrack extension area.
	3	*
	4	* (C) 2013 Astaro GmbH & Co KG
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
c539f017	11	#include <linux/export.h>
c539f017	12	#include <linux/types.h>
c539f017 FW	13
	14	#include <net/netfilter/nf_conntrack_ecache.h>
	15	#include <net/netfilter/nf_conntrack_labels.h>
	16
86ca02e7 JS	17	static spinlock_t nf_connlabels_lock;
86ca02e7 JS	18
c539f017 FW	19	int nf_connlabel_set(struct nf_conn *ct, u16 bit)
	20	{
	21	struct nf_conn_labels *labels = nf_ct_labels_find(ct);
	22
b4ef1599	23	if (!labels \|\| BIT_WORD(bit) >= labels->words)
c539f017 FW	24	return -ENOSPC;
	25
	26	if (test_bit(bit, labels->bits))
	27	return 0;
	28
797a7d66	29	if (!test_and_set_bit(bit, labels->bits))
0ceabd83	30	nf_conntrack_event_cache(IPCT_LABEL, ct);
c539f017 FW	31
	32	return 0;
	33	}
	34	EXPORT_SYMBOL_GPL(nf_connlabel_set);
	35
5a8145f7	36	static int replace_u32(u32 *address, u32 mask, u32 new)
9b21f6a9 FW	37	{
	38	u32 old, tmp;
	39
	40	do {
	41	old = *address;
	42	tmp = (old & mask) ^ new;
5a8145f7 FW	43	if (old == tmp)
5a8145f7 FW	44	return 0;
9b21f6a9	45	} while (cmpxchg(address, old, tmp) != old);
5a8145f7 FW	46
5a8145f7 FW	47	return 1;
9b21f6a9 FW	48	}
	49
	50	int nf_connlabels_replace(struct nf_conn *ct,
	51	const u32 *data,
	52	const u32 *mask, unsigned int words32)
	53	{
	54	struct nf_conn_labels *labels;
	55	unsigned int size, i;
5a8145f7	56	int changed = 0;
9b21f6a9 FW	57	u32 *dst;
	58
	59	labels = nf_ct_labels_find(ct);
	60	if (!labels)
	61	return -ENOSPC;
	62
	63	size = labels->words * sizeof(long);
	64	if (size < (words32 * sizeof(u32)))
	65	words32 = size / sizeof(u32);
	66
	67	dst = (u32 *) labels->bits;
5a8145f7 FW	68	for (i = 0; i < words32; i++)
5a8145f7 FW	69	changed \|= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
9b21f6a9 FW	70
	71	size /= sizeof(u32);
	72	for (i = words32; i < size; i++) /* pad */
	73	replace_u32(&dst[i], 0, 0);
	74
5a8145f7 FW	75	if (changed)
5a8145f7 FW	76	nf_conntrack_event_cache(IPCT_LABEL, ct);
9b21f6a9 FW	77	return 0;
	78	}
	79	EXPORT_SYMBOL_GPL(nf_connlabels_replace);
9b21f6a9	80
adff6c65	81	int nf_connlabels_get(struct net *net, unsigned int bits)
86ca02e7 JS	82	{
	83	size_t words;
	84
adff6c65 FW	85	words = BIT_WORD(bits) + 1;
adff6c65 FW	86	if (words > NF_CT_LABELS_MAX_SIZE / sizeof(long))
86ca02e7 JS	87	return -ERANGE;
86ca02e7 JS	88
86ca02e7 JS	89	spin_lock(&nf_connlabels_lock);
	90	net->ct.labels_used++;
	91	if (words > net->ct.label_words)
	92	net->ct.label_words = words;
	93	spin_unlock(&nf_connlabels_lock);
	94
	95	return 0;
	96	}
	97	EXPORT_SYMBOL_GPL(nf_connlabels_get);
	98
	99	void nf_connlabels_put(struct net *net)
	100	{
	101	spin_lock(&nf_connlabels_lock);
	102	net->ct.labels_used--;
	103	if (net->ct.labels_used == 0)
	104	net->ct.label_words = 0;
	105	spin_unlock(&nf_connlabels_lock);
	106	}
	107	EXPORT_SYMBOL_GPL(nf_connlabels_put);
	108
c539f017 FW	109	static struct nf_ct_ext_type labels_extend __read_mostly = {
	110	.len = sizeof(struct nf_conn_labels),
	111	.align = __alignof__(struct nf_conn_labels),
	112	.id = NF_CT_EXT_LABELS,
	113	};
	114
5f69b8f5	115	int nf_conntrack_labels_init(void)
c539f017	116	{
adff6c65 FW	117	BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
adff6c65 FW	118
86ca02e7	119	spin_lock_init(&nf_connlabels_lock);
5f69b8f5	120	return nf_ct_extend_register(&labels_extend);
c539f017 FW	121	}
c539f017 FW	122
5f69b8f5	123	void nf_conntrack_labels_fini(void)
c539f017	124	{
5f69b8f5	125	nf_ct_extend_unregister(&labels_extend);
c539f017	126	}