[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / nf_conntrack_expect.c

/* Expectation handling for nf_conntrack. */

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
 *
 * 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/types.h>
#include <linux/netfilter.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stddef.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/kernel.h>

#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_tuple.h>

LIST_HEAD(nf_conntrack_expect_list);
EXPORT_SYMBOL_GPL(nf_conntrack_expect_list);

struct kmem_cache *nf_conntrack_expect_cachep __read_mostly;
static unsigned int nf_conntrack_expect_next_id;

/* nf_conntrack_expect helper functions */
void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
{
	struct nf_conn_help *master_help = nfct_help(exp->master);

	NF_CT_ASSERT(master_help);
	NF_CT_ASSERT(!timer_pending(&exp->timeout));

	list_del(&exp->list);
	NF_CT_STAT_INC(expect_delete);
	master_help->expecting--;
	nf_conntrack_expect_put(exp);
}
EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);

static void expectation_timed_out(unsigned long ul_expect)
{
	struct nf_conntrack_expect *exp = (void *)ul_expect;

	write_lock_bh(&nf_conntrack_lock);
	nf_ct_unlink_expect(exp);
	write_unlock_bh(&nf_conntrack_lock);
	nf_conntrack_expect_put(exp);
}

struct nf_conntrack_expect *
__nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple)
{
	struct nf_conntrack_expect *i;

	list_for_each_entry(i, &nf_conntrack_expect_list, list) {
		if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask))
			return i;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(__nf_conntrack_expect_find);

/* Just find a expectation corresponding to a tuple. */
struct nf_conntrack_expect *
nf_conntrack_expect_find_get(const struct nf_conntrack_tuple *tuple)
{
	struct nf_conntrack_expect *i;

	read_lock_bh(&nf_conntrack_lock);
	i = __nf_conntrack_expect_find(tuple);
	if (i)
		atomic_inc(&i->use);
	read_unlock_bh(&nf_conntrack_lock);

	return i;
}
EXPORT_SYMBOL_GPL(nf_conntrack_expect_find_get);

/* If an expectation for this connection is found, it gets delete from
 * global list then returned. */
struct nf_conntrack_expect *
find_expectation(const struct nf_conntrack_tuple *tuple)
{
	struct nf_conntrack_expect *exp;

	exp = __nf_conntrack_expect_find(tuple);
	if (!exp)
		return NULL;

	/* If master is not in hash table yet (ie. packet hasn't left
	   this machine yet), how can other end know about expected?
	   Hence these are not the droids you are looking for (if
	   master ct never got confirmed, we'd hold a reference to it
	   and weird things would happen to future packets). */
	if (!nf_ct_is_confirmed(exp->master))
		return NULL;

	if (exp->flags & NF_CT_EXPECT_PERMANENT) {
		atomic_inc(&exp->use);
		return exp;
	} else if (del_timer(&exp->timeout)) {
		nf_ct_unlink_expect(exp);
		return exp;
	}

	return NULL;
}

/* delete all expectations for this conntrack */
void nf_ct_remove_expectations(struct nf_conn *ct)
{
	struct nf_conntrack_expect *i, *tmp;
	struct nf_conn_help *help = nfct_help(ct);

	/* Optimization: most connection never expect any others. */
	if (!help || help->expecting == 0)
		return;

	list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) {
		if (i->master == ct && del_timer(&i->timeout)) {
			nf_ct_unlink_expect(i);
			nf_conntrack_expect_put(i);
		}
	}
}
EXPORT_SYMBOL_GPL(nf_ct_remove_expectations);

/* Would two expected things clash? */
static inline int expect_clash(const struct nf_conntrack_expect *a,
			       const struct nf_conntrack_expect *b)
{
	/* Part covered by intersection of masks must be unequal,
	   otherwise they clash */
	struct nf_conntrack_tuple intersect_mask;
	int count;

	intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num;
	intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all;
	intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all;
	intersect_mask.dst.protonum = a->mask.dst.protonum
					& b->mask.dst.protonum;

	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
		intersect_mask.src.u3.all[count] =
			a->mask.src.u3.all[count] & b->mask.src.u3.all[count];
	}

	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
		intersect_mask.dst.u3.all[count] =
			a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count];
	}

	return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
}

static inline int expect_matches(const struct nf_conntrack_expect *a,
				 const struct nf_conntrack_expect *b)
{
	return a->master == b->master
		&& nf_ct_tuple_equal(&a->tuple, &b->tuple)
		&& nf_ct_tuple_equal(&a->mask, &b->mask);
}

/* Generally a bad idea to call this: could have matched already. */
void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp)
{
	struct nf_conntrack_expect *i;

	write_lock_bh(&nf_conntrack_lock);
	/* choose the oldest expectation to evict */
	list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
		if (expect_matches(i, exp) && del_timer(&i->timeout)) {
			nf_ct_unlink_expect(i);
			write_unlock_bh(&nf_conntrack_lock);
			nf_conntrack_expect_put(i);
			return;
		}
	}
	write_unlock_bh(&nf_conntrack_lock);
}
EXPORT_SYMBOL_GPL(nf_conntrack_unexpect_related);

/* We don't increase the master conntrack refcount for non-fulfilled
 * conntracks. During the conntrack destruction, the expectations are
 * always killed before the conntrack itself */
struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me)
{
	struct nf_conntrack_expect *new;

	new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC);
	if (!new)
		return NULL;

	new->master = me;
	atomic_set(&new->use, 1);
	return new;
}
EXPORT_SYMBOL_GPL(nf_conntrack_expect_alloc);

void nf_conntrack_expect_init(struct nf_conntrack_expect *exp, int family,
			      union nf_conntrack_address *saddr,
			      union nf_conntrack_address *daddr,
			      u_int8_t proto, __be16 *src, __be16 *dst)
{
	int len;

	if (family == AF_INET)
		len = 4;
	else
		len = 16;

	exp->flags = 0;
	exp->expectfn = NULL;
	exp->helper = NULL;
	exp->tuple.src.l3num = family;
	exp->tuple.dst.protonum = proto;
	exp->mask.src.l3num = 0xFFFF;
	exp->mask.dst.protonum = 0xFF;

	if (saddr) {
		memcpy(&exp->tuple.src.u3, saddr, len);
		if (sizeof(exp->tuple.src.u3) > len)
			/* address needs to be cleared for nf_ct_tuple_equal */
			memset((void *)&exp->tuple.src.u3 + len, 0x00,
			       sizeof(exp->tuple.src.u3) - len);
		memset(&exp->mask.src.u3, 0xFF, len);
		if (sizeof(exp->mask.src.u3) > len)
			memset((void *)&exp->mask.src.u3 + len, 0x00,
			       sizeof(exp->mask.src.u3) - len);
	} else {
		memset(&exp->tuple.src.u3, 0x00, sizeof(exp->tuple.src.u3));
		memset(&exp->mask.src.u3, 0x00, sizeof(exp->mask.src.u3));
	}

	if (daddr) {
		memcpy(&exp->tuple.dst.u3, daddr, len);
		if (sizeof(exp->tuple.dst.u3) > len)
			/* address needs to be cleared for nf_ct_tuple_equal */
			memset((void *)&exp->tuple.dst.u3 + len, 0x00,
			       sizeof(exp->tuple.dst.u3) - len);
		memset(&exp->mask.dst.u3, 0xFF, len);
		if (sizeof(exp->mask.dst.u3) > len)
			memset((void *)&exp->mask.dst.u3 + len, 0x00,
			       sizeof(exp->mask.dst.u3) - len);
	} else {
		memset(&exp->tuple.dst.u3, 0x00, sizeof(exp->tuple.dst.u3));
		memset(&exp->mask.dst.u3, 0x00, sizeof(exp->mask.dst.u3));
	}

	if (src) {
		exp->tuple.src.u.all = (__force u16)*src;
		exp->mask.src.u.all = 0xFFFF;
	} else {
		exp->tuple.src.u.all = 0;
		exp->mask.src.u.all = 0;
	}

	if (dst) {
		exp->tuple.dst.u.all = (__force u16)*dst;
		exp->mask.dst.u.all = 0xFFFF;
	} else {
		exp->tuple.dst.u.all = 0;
		exp->mask.dst.u.all = 0;
	}
}
EXPORT_SYMBOL_GPL(nf_conntrack_expect_init);

void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
{
	if (atomic_dec_and_test(&exp->use))
		kmem_cache_free(nf_conntrack_expect_cachep, exp);
}
EXPORT_SYMBOL_GPL(nf_conntrack_expect_put);

static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp)
{
	struct nf_conn_help *master_help = nfct_help(exp->master);

	atomic_inc(&exp->use);
	master_help->expecting++;
	list_add(&exp->list, &nf_conntrack_expect_list);

	setup_timer(&exp->timeout, expectation_timed_out, (unsigned long)exp);
	exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
	add_timer(&exp->timeout);

	exp->id = ++nf_conntrack_expect_next_id;
	atomic_inc(&exp->use);
	NF_CT_STAT_INC(expect_create);
}

/* Race with expectations being used means we could have none to find; OK. */
static void evict_oldest_expect(struct nf_conn *master)
{
	struct nf_conntrack_expect *i;

	list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
		if (i->master == master) {
			if (del_timer(&i->timeout)) {
				nf_ct_unlink_expect(i);
				nf_conntrack_expect_put(i);
			}
			break;
		}
	}
}

static inline int refresh_timer(struct nf_conntrack_expect *i)
{
	struct nf_conn_help *master_help = nfct_help(i->master);

	if (!del_timer(&i->timeout))
		return 0;

	i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
	add_timer(&i->timeout);
	return 1;
}

int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
{
	struct nf_conntrack_expect *i;
	struct nf_conn *master = expect->master;
	struct nf_conn_help *master_help = nfct_help(master);
	int ret;

	NF_CT_ASSERT(master_help);

	write_lock_bh(&nf_conntrack_lock);
	list_for_each_entry(i, &nf_conntrack_expect_list, list) {
		if (expect_matches(i, expect)) {
			/* Refresh timer: if it's dying, ignore.. */
			if (refresh_timer(i)) {
				ret = 0;
				goto out;
			}
		} else if (expect_clash(i, expect)) {
			ret = -EBUSY;
			goto out;
		}
	}
	/* Will be over limit? */
	if (master_help->helper->max_expected &&
	    master_help->expecting >= master_help->helper->max_expected)
		evict_oldest_expect(master);

	nf_conntrack_expect_insert(expect);
	nf_conntrack_expect_event(IPEXP_NEW, expect);
	ret = 0;
out:
	write_unlock_bh(&nf_conntrack_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(nf_conntrack_expect_related);

#ifdef CONFIG_PROC_FS
static void *exp_seq_start(struct seq_file *s, loff_t *pos)
{
	struct list_head *e = &nf_conntrack_expect_list;
	loff_t i;

	/* strange seq_file api calls stop even if we fail,
	 * thus we need to grab lock since stop unlocks */
	read_lock_bh(&nf_conntrack_lock);

	if (list_empty(e))
		return NULL;

	for (i = 0; i <= *pos; i++) {
		e = e->next;
		if (e == &nf_conntrack_expect_list)
			return NULL;
	}
	return e;
}

static void *exp_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
	struct list_head *e = v;

	++*pos;
	e = e->next;

	if (e == &nf_conntrack_expect_list)
		return NULL;

	return e;
}

static void exp_seq_stop(struct seq_file *s, void *v)
{
	read_unlock_bh(&nf_conntrack_lock);
}

static int exp_seq_show(struct seq_file *s, void *v)
{
	struct nf_conntrack_expect *expect = v;

	if (expect->timeout.function)
		seq_printf(s, "%ld ", timer_pending(&expect->timeout)
			   ? (long)(expect->timeout.expires - jiffies)/HZ : 0);
	else
		seq_printf(s, "- ");
	seq_printf(s, "l3proto = %u proto=%u ",
		   expect->tuple.src.l3num,
		   expect->tuple.dst.protonum);
	print_tuple(s, &expect->tuple,
		    __nf_ct_l3proto_find(expect->tuple.src.l3num),
		    __nf_ct_l4proto_find(expect->tuple.src.l3num,
				       expect->tuple.dst.protonum));
	return seq_putc(s, '\n');
}

static struct seq_operations exp_seq_ops = {
	.start = exp_seq_start,
	.next = exp_seq_next,
	.stop = exp_seq_stop,
	.show = exp_seq_show
};

static int exp_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &exp_seq_ops);
}

const struct file_operations exp_file_ops = {
	.owner   = THIS_MODULE,
	.open    = exp_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release
};
#endif /* CONFIG_PROC_FS */
Commit	Line	Data
77ab9cff MJ	1	/* Expectation handling for nf_conntrack. */
	2
	3	/* (C) 1999-2001 Paul `Rusty' Russell
	4	* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
	5	* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/types.h>
	13	#include <linux/netfilter.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/proc_fs.h>
	16	#include <linux/seq_file.h>
	17	#include <linux/stddef.h>
	18	#include <linux/slab.h>
	19	#include <linux/err.h>
	20	#include <linux/percpu.h>
	21	#include <linux/kernel.h>
	22
	23	#include <net/netfilter/nf_conntrack.h>
	24	#include <net/netfilter/nf_conntrack_core.h>
	25	#include <net/netfilter/nf_conntrack_expect.h>
	26	#include <net/netfilter/nf_conntrack_helper.h>
	27	#include <net/netfilter/nf_conntrack_tuple.h>
	28
	29	LIST_HEAD(nf_conntrack_expect_list);
13b18339 PM	30	EXPORT_SYMBOL_GPL(nf_conntrack_expect_list);
13b18339 PM	31
e18b890b	32	struct kmem_cache *nf_conntrack_expect_cachep __read_mostly;
77ab9cff MJ	33	static unsigned int nf_conntrack_expect_next_id;
	34
	35	/* nf_conntrack_expect helper functions */
	36	void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
	37	{
	38	struct nf_conn_help *master_help = nfct_help(exp->master);
	39
	40	NF_CT_ASSERT(master_help);
	41	NF_CT_ASSERT(!timer_pending(&exp->timeout));
	42
	43	list_del(&exp->list);
	44	NF_CT_STAT_INC(expect_delete);
	45	master_help->expecting--;
	46	nf_conntrack_expect_put(exp);
	47	}
13b18339	48	EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);
77ab9cff MJ	49
	50	static void expectation_timed_out(unsigned long ul_expect)
	51	{
	52	struct nf_conntrack_expect exp = (void )ul_expect;
	53
	54	write_lock_bh(&nf_conntrack_lock);
	55	nf_ct_unlink_expect(exp);
	56	write_unlock_bh(&nf_conntrack_lock);
	57	nf_conntrack_expect_put(exp);
	58	}
	59
	60	struct nf_conntrack_expect *
	61	__nf_conntrack_expect_find(const struct nf_conntrack_tuple *tuple)
	62	{
	63	struct nf_conntrack_expect *i;
	64
	65	list_for_each_entry(i, &nf_conntrack_expect_list, list) {
	66	if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask))
	67	return i;
	68	}
	69	return NULL;
	70	}
13b18339	71	EXPORT_SYMBOL_GPL(__nf_conntrack_expect_find);
77ab9cff MJ	72
	73	/* Just find a expectation corresponding to a tuple. */
	74	struct nf_conntrack_expect *
468ec44b	75	nf_conntrack_expect_find_get(const struct nf_conntrack_tuple *tuple)
77ab9cff MJ	76	{
	77	struct nf_conntrack_expect *i;
	78
	79	read_lock_bh(&nf_conntrack_lock);
	80	i = __nf_conntrack_expect_find(tuple);
	81	if (i)
	82	atomic_inc(&i->use);
	83	read_unlock_bh(&nf_conntrack_lock);
	84
	85	return i;
	86	}
13b18339	87	EXPORT_SYMBOL_GPL(nf_conntrack_expect_find_get);
77ab9cff MJ	88
	89	/* If an expectation for this connection is found, it gets delete from
	90	* global list then returned. */
	91	struct nf_conntrack_expect *
	92	find_expectation(const struct nf_conntrack_tuple *tuple)
	93	{
ece00641 YK	94	struct nf_conntrack_expect *exp;
	95
	96	exp = __nf_conntrack_expect_find(tuple);
	97	if (!exp)
	98	return NULL;
77ab9cff	99
77ab9cff MJ	100	/* If master is not in hash table yet (ie. packet hasn't left
	101	this machine yet), how can other end know about expected?
	102	Hence these are not the droids you are looking for (if
	103	master ct never got confirmed, we'd hold a reference to it
	104	and weird things would happen to future packets). */
ece00641 YK	105	if (!nf_ct_is_confirmed(exp->master))
	106	return NULL;
	107
	108	if (exp->flags & NF_CT_EXPECT_PERMANENT) {
	109	atomic_inc(&exp->use);
	110	return exp;
	111	} else if (del_timer(&exp->timeout)) {
	112	nf_ct_unlink_expect(exp);
	113	return exp;
77ab9cff	114	}
ece00641	115
77ab9cff MJ	116	return NULL;
	117	}
	118
	119	/* delete all expectations for this conntrack */
	120	void nf_ct_remove_expectations(struct nf_conn *ct)
	121	{
	122	struct nf_conntrack_expect i, tmp;
	123	struct nf_conn_help *help = nfct_help(ct);
	124
	125	/* Optimization: most connection never expect any others. */
	126	if (!help \|\| help->expecting == 0)
	127	return;
	128
	129	list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) {
	130	if (i->master == ct && del_timer(&i->timeout)) {
	131	nf_ct_unlink_expect(i);
	132	nf_conntrack_expect_put(i);
601e68e1	133	}
77ab9cff MJ	134	}
77ab9cff MJ	135	}
13b18339	136	EXPORT_SYMBOL_GPL(nf_ct_remove_expectations);
77ab9cff MJ	137
	138	/* Would two expected things clash? */
	139	static inline int expect_clash(const struct nf_conntrack_expect *a,
	140	const struct nf_conntrack_expect *b)
	141	{
	142	/* Part covered by intersection of masks must be unequal,
	143	otherwise they clash */
	144	struct nf_conntrack_tuple intersect_mask;
	145	int count;
	146
	147	intersect_mask.src.l3num = a->mask.src.l3num & b->mask.src.l3num;
	148	intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all;
	149	intersect_mask.dst.u.all = a->mask.dst.u.all & b->mask.dst.u.all;
	150	intersect_mask.dst.protonum = a->mask.dst.protonum
	151	& b->mask.dst.protonum;
	152
	153	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
	154	intersect_mask.src.u3.all[count] =
	155	a->mask.src.u3.all[count] & b->mask.src.u3.all[count];
	156	}
	157
	158	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
	159	intersect_mask.dst.u3.all[count] =
	160	a->mask.dst.u3.all[count] & b->mask.dst.u3.all[count];
	161	}
	162
	163	return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
	164	}
	165
	166	static inline int expect_matches(const struct nf_conntrack_expect *a,
	167	const struct nf_conntrack_expect *b)
	168	{
	169	return a->master == b->master
	170	&& nf_ct_tuple_equal(&a->tuple, &b->tuple)
	171	&& nf_ct_tuple_equal(&a->mask, &b->mask);
	172	}
	173
	174	/* Generally a bad idea to call this: could have matched already. */
	175	void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp)
	176	{
	177	struct nf_conntrack_expect *i;
	178
	179	write_lock_bh(&nf_conntrack_lock);
59c51591	180	/* choose the oldest expectation to evict */
77ab9cff MJ	181	list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
	182	if (expect_matches(i, exp) && del_timer(&i->timeout)) {
	183	nf_ct_unlink_expect(i);
	184	write_unlock_bh(&nf_conntrack_lock);
	185	nf_conntrack_expect_put(i);
	186	return;
	187	}
	188	}
	189	write_unlock_bh(&nf_conntrack_lock);
	190	}
13b18339	191	EXPORT_SYMBOL_GPL(nf_conntrack_unexpect_related);
77ab9cff MJ	192
	193	/* We don't increase the master conntrack refcount for non-fulfilled
	194	* conntracks. During the conntrack destruction, the expectations are
	195	* always killed before the conntrack itself */
	196	struct nf_conntrack_expect nf_conntrack_expect_alloc(struct nf_conn me)
	197	{
	198	struct nf_conntrack_expect *new;
	199
	200	new = kmem_cache_alloc(nf_conntrack_expect_cachep, GFP_ATOMIC);
	201	if (!new)
	202	return NULL;
	203
	204	new->master = me;
	205	atomic_set(&new->use, 1);
	206	return new;
	207	}
13b18339	208	EXPORT_SYMBOL_GPL(nf_conntrack_expect_alloc);
77ab9cff	209
d6a9b650 PM	210	void nf_conntrack_expect_init(struct nf_conntrack_expect *exp, int family,
	211	union nf_conntrack_address *saddr,
	212	union nf_conntrack_address *daddr,
	213	u_int8_t proto, __be16 src, __be16 dst)
	214	{
	215	int len;
	216
	217	if (family == AF_INET)
	218	len = 4;
	219	else
	220	len = 16;
	221
	222	exp->flags = 0;
	223	exp->expectfn = NULL;
	224	exp->helper = NULL;
	225	exp->tuple.src.l3num = family;
	226	exp->tuple.dst.protonum = proto;
	227	exp->mask.src.l3num = 0xFFFF;
	228	exp->mask.dst.protonum = 0xFF;
	229
	230	if (saddr) {
	231	memcpy(&exp->tuple.src.u3, saddr, len);
	232	if (sizeof(exp->tuple.src.u3) > len)
	233	/* address needs to be cleared for nf_ct_tuple_equal */
	234	memset((void *)&exp->tuple.src.u3 + len, 0x00,
	235	sizeof(exp->tuple.src.u3) - len);
	236	memset(&exp->mask.src.u3, 0xFF, len);
	237	if (sizeof(exp->mask.src.u3) > len)
	238	memset((void *)&exp->mask.src.u3 + len, 0x00,
	239	sizeof(exp->mask.src.u3) - len);
	240	} else {
	241	memset(&exp->tuple.src.u3, 0x00, sizeof(exp->tuple.src.u3));
	242	memset(&exp->mask.src.u3, 0x00, sizeof(exp->mask.src.u3));
	243	}
	244
	245	if (daddr) {
	246	memcpy(&exp->tuple.dst.u3, daddr, len);
	247	if (sizeof(exp->tuple.dst.u3) > len)
	248	/* address needs to be cleared for nf_ct_tuple_equal */
	249	memset((void *)&exp->tuple.dst.u3 + len, 0x00,
	250	sizeof(exp->tuple.dst.u3) - len);
	251	memset(&exp->mask.dst.u3, 0xFF, len);
	252	if (sizeof(exp->mask.dst.u3) > len)
	253	memset((void *)&exp->mask.dst.u3 + len, 0x00,
	254	sizeof(exp->mask.dst.u3) - len);
	255	} else {
	256	memset(&exp->tuple.dst.u3, 0x00, sizeof(exp->tuple.dst.u3));
	257	memset(&exp->mask.dst.u3, 0x00, sizeof(exp->mask.dst.u3));
	258	}
	259
	260	if (src) {
	261	exp->tuple.src.u.all = (__force u16)*src;
	262	exp->mask.src.u.all = 0xFFFF;
	263	} else {
	264	exp->tuple.src.u.all = 0;
	265	exp->mask.src.u.all = 0;
	266	}
	267
	268	if (dst) {
	269	exp->tuple.dst.u.all = (__force u16)*dst;
	270	exp->mask.dst.u.all = 0xFFFF;
	271	} else {
	272	exp->tuple.dst.u.all = 0;
	273	exp->mask.dst.u.all = 0;
274	}
275	}
276	EXPORT_SYMBOL_GPL(nf_conntrack_expect_init);
277
77ab9cff MJ	278	void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
	279	{
	280	if (atomic_dec_and_test(&exp->use))
	281	kmem_cache_free(nf_conntrack_expect_cachep, exp);
	282	}
13b18339	283	EXPORT_SYMBOL_GPL(nf_conntrack_expect_put);
77ab9cff MJ	284
	285	static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp)
	286	{
	287	struct nf_conn_help *master_help = nfct_help(exp->master);
	288
	289	atomic_inc(&exp->use);
	290	master_help->expecting++;
	291	list_add(&exp->list, &nf_conntrack_expect_list);
	292
e6f689db	293	setup_timer(&exp->timeout, expectation_timed_out, (unsigned long)exp);
77ab9cff MJ	294	exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
	295	add_timer(&exp->timeout);
	296
	297	exp->id = ++nf_conntrack_expect_next_id;
	298	atomic_inc(&exp->use);
	299	NF_CT_STAT_INC(expect_create);
	300	}
	301
	302	/* Race with expectations being used means we could have none to find; OK. */
	303	static void evict_oldest_expect(struct nf_conn *master)
	304	{
	305	struct nf_conntrack_expect *i;
	306
	307	list_for_each_entry_reverse(i, &nf_conntrack_expect_list, list) {
	308	if (i->master == master) {
	309	if (del_timer(&i->timeout)) {
	310	nf_ct_unlink_expect(i);
	311	nf_conntrack_expect_put(i);
	312	}
	313	break;
	314	}
	315	}
	316	}
	317
	318	static inline int refresh_timer(struct nf_conntrack_expect *i)
	319	{
	320	struct nf_conn_help *master_help = nfct_help(i->master);
	321
	322	if (!del_timer(&i->timeout))
	323	return 0;
	324
	325	i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
	326	add_timer(&i->timeout);
	327	return 1;
	328	}
	329
	330	int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
	331	{
	332	struct nf_conntrack_expect *i;
	333	struct nf_conn *master = expect->master;
	334	struct nf_conn_help *master_help = nfct_help(master);
	335	int ret;
	336
	337	NF_CT_ASSERT(master_help);
	338
	339	write_lock_bh(&nf_conntrack_lock);
	340	list_for_each_entry(i, &nf_conntrack_expect_list, list) {
	341	if (expect_matches(i, expect)) {
	342	/* Refresh timer: if it's dying, ignore.. */
	343	if (refresh_timer(i)) {
	344	ret = 0;
	345	goto out;
	346	}
	347	} else if (expect_clash(i, expect)) {
	348	ret = -EBUSY;
	349	goto out;
	350	}
	351	}
	352	/* Will be over limit? */
	353	if (master_help->helper->max_expected &&
	354	master_help->expecting >= master_help->helper->max_expected)
	355	evict_oldest_expect(master);
	356
	357	nf_conntrack_expect_insert(expect);
358	nf_conntrack_expect_event(IPEXP_NEW, expect);
359	ret = 0;
360	out:
361	write_unlock_bh(&nf_conntrack_lock);
362	return ret;
363	}
13b18339	364	EXPORT_SYMBOL_GPL(nf_conntrack_expect_related);
77ab9cff MJ	365
	366	#ifdef CONFIG_PROC_FS
	367	static void exp_seq_start(struct seq_file s, loff_t *pos)
	368	{
	369	struct list_head *e = &nf_conntrack_expect_list;
	370	loff_t i;
	371
	372	/* strange seq_file api calls stop even if we fail,
	373	* thus we need to grab lock since stop unlocks */
	374	read_lock_bh(&nf_conntrack_lock);
	375
	376	if (list_empty(e))
	377	return NULL;
	378
	379	for (i = 0; i <= *pos; i++) {
	380	e = e->next;
	381	if (e == &nf_conntrack_expect_list)
	382	return NULL;
	383	}
	384	return e;
	385	}
	386
	387	static void exp_seq_next(struct seq_file s, void v, loff_t pos)
	388	{
	389	struct list_head *e = v;
	390
	391	++*pos;
	392	e = e->next;
	393
	394	if (e == &nf_conntrack_expect_list)
	395	return NULL;
	396
	397	return e;
	398	}
	399
	400	static void exp_seq_stop(struct seq_file s, void v)
	401	{
	402	read_unlock_bh(&nf_conntrack_lock);
	403	}
	404
	405	static int exp_seq_show(struct seq_file s, void v)
	406	{
	407	struct nf_conntrack_expect *expect = v;
	408
	409	if (expect->timeout.function)
	410	seq_printf(s, "%ld ", timer_pending(&expect->timeout)
	411	? (long)(expect->timeout.expires - jiffies)/HZ : 0);
	412	else
	413	seq_printf(s, "- ");
	414	seq_printf(s, "l3proto = %u proto=%u ",
	415	expect->tuple.src.l3num,
	416	expect->tuple.dst.protonum);
	417	print_tuple(s, &expect->tuple,
	418	__nf_ct_l3proto_find(expect->tuple.src.l3num),
605dcad6	419	__nf_ct_l4proto_find(expect->tuple.src.l3num,
77ab9cff MJ	420	expect->tuple.dst.protonum));
	421	return seq_putc(s, '\n');
	422	}
	423
	424	static struct seq_operations exp_seq_ops = {
	425	.start = exp_seq_start,
	426	.next = exp_seq_next,
	427	.stop = exp_seq_stop,
	428	.show = exp_seq_show
	429	};
	430
	431	static int exp_open(struct inode inode, struct file file)
	432	{
	433	return seq_open(file, &exp_seq_ops);
	434	}
	435
da7071d7	436	const struct file_operations exp_file_ops = {
77ab9cff MJ	437	.owner = THIS_MODULE,
	438	.open = exp_open,
	439	.read = seq_read,
	440	.llseek = seq_lseek,
	441	.release = seq_release
	442	};
	443	#endif /* CONFIG_PROC_FS */