[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_ct_expect_list);
EXPORT_SYMBOL_GPL(nf_ct_expect_list);

struct kmem_cache *nf_ct_expect_cachep __read_mostly;
static unsigned int nf_ct_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_ct_expect_put(exp);
}
EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);

static void nf_ct_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_ct_expect_put(exp);
}

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

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

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

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

	return i;
}
EXPORT_SYMBOL_GPL(nf_ct_expect_find_get);

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

	exp = __nf_ct_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_ct_expect_list, list) {
		if (i->master == ct && del_timer(&i->timeout)) {
			nf_ct_unlink_expect(i);
			nf_ct_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_mask intersect_mask;
	int count;

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

	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];
	}

	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_mask_equal(&a->mask, &b->mask);
}

/* Generally a bad idea to call this: could have matched already. */
void nf_ct_unexpect_related(struct nf_conntrack_expect *exp)
{
	write_lock_bh(&nf_conntrack_lock);
	if (del_timer(&exp->timeout)) {
		nf_ct_unlink_expect(exp);
		nf_ct_expect_put(exp);
	}
	write_unlock_bh(&nf_conntrack_lock);
}
EXPORT_SYMBOL_GPL(nf_ct_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_ct_expect_alloc(struct nf_conn *me)
{
	struct nf_conntrack_expect *new;

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

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

void nf_ct_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;

	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 (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;
	}

	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);

	exp->tuple.dst.u.all = (__force u16)*dst;
}
EXPORT_SYMBOL_GPL(nf_ct_expect_init);

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

static void nf_ct_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_ct_expect_list);

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

	exp->id = ++nf_ct_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_ct_expect_list, list) {
		if (i->master == master) {
			if (del_timer(&i->timeout)) {
				nf_ct_unlink_expect(i);
				nf_ct_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_ct_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);
	if (!master_help->helper) {
		ret = -ESHUTDOWN;
		goto out;
	}
	list_for_each_entry(i, &nf_ct_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_ct_expect_insert(expect);
	nf_ct_expect_event(IPEXP_NEW, expect);
	ret = 0;
out:
	write_unlock_bh(&nf_conntrack_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_expect_related);

#ifdef CONFIG_PROC_FS
static void *exp_seq_start(struct seq_file *s, loff_t *pos)
{
	struct list_head *e = &nf_ct_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_ct_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_ct_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
6823645d PM	29	LIST_HEAD(nf_ct_expect_list);
6823645d PM	30	EXPORT_SYMBOL_GPL(nf_ct_expect_list);
13b18339	31
6823645d PM	32	struct kmem_cache *nf_ct_expect_cachep __read_mostly;
6823645d PM	33	static unsigned int nf_ct_expect_next_id;
77ab9cff MJ	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--;
6823645d	46	nf_ct_expect_put(exp);
77ab9cff	47	}
13b18339	48	EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);
77ab9cff	49
6823645d	50	static void nf_ct_expectation_timed_out(unsigned long ul_expect)
77ab9cff MJ	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);
6823645d	57	nf_ct_expect_put(exp);
77ab9cff MJ	58	}
	59
	60	struct nf_conntrack_expect *
6823645d	61	__nf_ct_expect_find(const struct nf_conntrack_tuple *tuple)
77ab9cff MJ	62	{
	63	struct nf_conntrack_expect *i;
	64
6823645d	65	list_for_each_entry(i, &nf_ct_expect_list, list) {
77ab9cff MJ	66	if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask))
	67	return i;
	68	}
	69	return NULL;
	70	}
6823645d	71	EXPORT_SYMBOL_GPL(__nf_ct_expect_find);
77ab9cff MJ	72
	73	/* Just find a expectation corresponding to a tuple. */
	74	struct nf_conntrack_expect *
6823645d	75	nf_ct_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);
6823645d	80	i = __nf_ct_expect_find(tuple);
77ab9cff MJ	81	if (i)
	82	atomic_inc(&i->use);
	83	read_unlock_bh(&nf_conntrack_lock);
	84
	85	return i;
	86	}
6823645d	87	EXPORT_SYMBOL_GPL(nf_ct_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 *
6823645d	92	nf_ct_find_expectation(const struct nf_conntrack_tuple *tuple)
77ab9cff	93	{
ece00641 YK	94	struct nf_conntrack_expect *exp;
ece00641 YK	95
6823645d	96	exp = __nf_ct_expect_find(tuple);
ece00641 YK	97	if (!exp)
ece00641 YK	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
6823645d	129	list_for_each_entry_safe(i, tmp, &nf_ct_expect_list, list) {
77ab9cff MJ	130	if (i->master == ct && del_timer(&i->timeout)) {
77ab9cff MJ	131	nf_ct_unlink_expect(i);
6823645d	132	nf_ct_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 */
d4156e8c	144	struct nf_conntrack_tuple_mask intersect_mask;
77ab9cff MJ	145	int count;
77ab9cff MJ	146
77ab9cff	147	intersect_mask.src.u.all = a->mask.src.u.all & b->mask.src.u.all;
77ab9cff MJ	148
	149	for (count = 0; count < NF_CT_TUPLE_L3SIZE; count++){
	150	intersect_mask.src.u3.all[count] =
	151	a->mask.src.u3.all[count] & b->mask.src.u3.all[count];
	152	}
	153
77ab9cff MJ	154	return nf_ct_tuple_mask_cmp(&a->tuple, &b->tuple, &intersect_mask);
	155	}
	156
	157	static inline int expect_matches(const struct nf_conntrack_expect *a,
	158	const struct nf_conntrack_expect *b)
	159	{
	160	return a->master == b->master
	161	&& nf_ct_tuple_equal(&a->tuple, &b->tuple)
d4156e8c	162	&& nf_ct_tuple_mask_equal(&a->mask, &b->mask);
77ab9cff MJ	163	}
	164
	165	/* Generally a bad idea to call this: could have matched already. */
6823645d	166	void nf_ct_unexpect_related(struct nf_conntrack_expect *exp)
77ab9cff	167	{
77ab9cff	168	write_lock_bh(&nf_conntrack_lock);
4e1d4e6c PM	169	if (del_timer(&exp->timeout)) {
	170	nf_ct_unlink_expect(exp);
	171	nf_ct_expect_put(exp);
77ab9cff MJ	172	}
	173	write_unlock_bh(&nf_conntrack_lock);
	174	}
6823645d	175	EXPORT_SYMBOL_GPL(nf_ct_unexpect_related);
77ab9cff MJ	176
	177	/* We don't increase the master conntrack refcount for non-fulfilled
	178	* conntracks. During the conntrack destruction, the expectations are
	179	* always killed before the conntrack itself */
6823645d	180	struct nf_conntrack_expect nf_ct_expect_alloc(struct nf_conn me)
77ab9cff MJ	181	{
	182	struct nf_conntrack_expect *new;
	183
6823645d	184	new = kmem_cache_alloc(nf_ct_expect_cachep, GFP_ATOMIC);
77ab9cff MJ	185	if (!new)
	186	return NULL;
	187
	188	new->master = me;
	189	atomic_set(&new->use, 1);
	190	return new;
	191	}
6823645d	192	EXPORT_SYMBOL_GPL(nf_ct_expect_alloc);
77ab9cff	193
6823645d PM	194	void nf_ct_expect_init(struct nf_conntrack_expect *exp, int family,
	195	union nf_conntrack_address *saddr,
	196	union nf_conntrack_address *daddr,
	197	u_int8_t proto, __be16 src, __be16 dst)
d6a9b650 PM	198	{
	199	int len;
	200
	201	if (family == AF_INET)
	202	len = 4;
	203	else
	204	len = 16;
	205
	206	exp->flags = 0;
	207	exp->expectfn = NULL;
	208	exp->helper = NULL;
	209	exp->tuple.src.l3num = family;
	210	exp->tuple.dst.protonum = proto;
d6a9b650 PM	211
	212	if (saddr) {
	213	memcpy(&exp->tuple.src.u3, saddr, len);
	214	if (sizeof(exp->tuple.src.u3) > len)
	215	/* address needs to be cleared for nf_ct_tuple_equal */
	216	memset((void *)&exp->tuple.src.u3 + len, 0x00,
	217	sizeof(exp->tuple.src.u3) - len);
	218	memset(&exp->mask.src.u3, 0xFF, len);
	219	if (sizeof(exp->mask.src.u3) > len)
	220	memset((void *)&exp->mask.src.u3 + len, 0x00,
	221	sizeof(exp->mask.src.u3) - len);
	222	} else {
	223	memset(&exp->tuple.src.u3, 0x00, sizeof(exp->tuple.src.u3));
	224	memset(&exp->mask.src.u3, 0x00, sizeof(exp->mask.src.u3));
	225	}
	226
d6a9b650 PM	227	if (src) {
	228	exp->tuple.src.u.all = (__force u16)*src;
	229	exp->mask.src.u.all = 0xFFFF;
	230	} else {
	231	exp->tuple.src.u.all = 0;
	232	exp->mask.src.u.all = 0;
	233	}
	234
d4156e8c PM	235	memcpy(&exp->tuple.dst.u3, daddr, len);
	236	if (sizeof(exp->tuple.dst.u3) > len)
	237	/* address needs to be cleared for nf_ct_tuple_equal */
	238	memset((void *)&exp->tuple.dst.u3 + len, 0x00,
	239	sizeof(exp->tuple.dst.u3) - len);
	240
	241	exp->tuple.dst.u.all = (__force u16)*dst;
d6a9b650	242	}
6823645d	243	EXPORT_SYMBOL_GPL(nf_ct_expect_init);
d6a9b650	244
6823645d	245	void nf_ct_expect_put(struct nf_conntrack_expect *exp)
77ab9cff MJ	246	{
77ab9cff MJ	247	if (atomic_dec_and_test(&exp->use))
6823645d	248	kmem_cache_free(nf_ct_expect_cachep, exp);
77ab9cff	249	}
6823645d	250	EXPORT_SYMBOL_GPL(nf_ct_expect_put);
77ab9cff	251
6823645d	252	static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
77ab9cff MJ	253	{
	254	struct nf_conn_help *master_help = nfct_help(exp->master);
	255
	256	atomic_inc(&exp->use);
	257	master_help->expecting++;
6823645d	258	list_add(&exp->list, &nf_ct_expect_list);
77ab9cff	259
6823645d PM	260	setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
6823645d PM	261	(unsigned long)exp);
77ab9cff MJ	262	exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
	263	add_timer(&exp->timeout);
	264
6823645d	265	exp->id = ++nf_ct_expect_next_id;
77ab9cff MJ	266	atomic_inc(&exp->use);
	267	NF_CT_STAT_INC(expect_create);
	268	}
	269
	270	/* Race with expectations being used means we could have none to find; OK. */
	271	static void evict_oldest_expect(struct nf_conn *master)
	272	{
	273	struct nf_conntrack_expect *i;
	274
6823645d	275	list_for_each_entry_reverse(i, &nf_ct_expect_list, list) {
77ab9cff MJ	276	if (i->master == master) {
	277	if (del_timer(&i->timeout)) {
	278	nf_ct_unlink_expect(i);
6823645d	279	nf_ct_expect_put(i);
77ab9cff MJ	280	}
	281	break;
	282	}
	283	}
	284	}
	285
	286	static inline int refresh_timer(struct nf_conntrack_expect *i)
	287	{
	288	struct nf_conn_help *master_help = nfct_help(i->master);
	289
	290	if (!del_timer(&i->timeout))
	291	return 0;
	292
	293	i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
	294	add_timer(&i->timeout);
	295	return 1;
	296	}
	297
6823645d	298	int nf_ct_expect_related(struct nf_conntrack_expect *expect)
77ab9cff MJ	299	{
	300	struct nf_conntrack_expect *i;
	301	struct nf_conn *master = expect->master;
	302	struct nf_conn_help *master_help = nfct_help(master);
	303	int ret;
	304
	305	NF_CT_ASSERT(master_help);
	306
	307	write_lock_bh(&nf_conntrack_lock);
3c158f7f PM	308	if (!master_help->helper) {
	309	ret = -ESHUTDOWN;
	310	goto out;
	311	}
6823645d	312	list_for_each_entry(i, &nf_ct_expect_list, list) {
77ab9cff MJ	313	if (expect_matches(i, expect)) {
	314	/* Refresh timer: if it's dying, ignore.. */
	315	if (refresh_timer(i)) {
	316	ret = 0;
	317	goto out;
	318	}
	319	} else if (expect_clash(i, expect)) {
	320	ret = -EBUSY;
	321	goto out;
	322	}
	323	}
	324	/* Will be over limit? */
	325	if (master_help->helper->max_expected &&
	326	master_help->expecting >= master_help->helper->max_expected)
	327	evict_oldest_expect(master);
	328
6823645d PM	329	nf_ct_expect_insert(expect);
6823645d PM	330	nf_ct_expect_event(IPEXP_NEW, expect);
77ab9cff MJ	331	ret = 0;
	332	out:
	333	write_unlock_bh(&nf_conntrack_lock);
	334	return ret;
	335	}
6823645d	336	EXPORT_SYMBOL_GPL(nf_ct_expect_related);
77ab9cff MJ	337
	338	#ifdef CONFIG_PROC_FS
	339	static void exp_seq_start(struct seq_file s, loff_t *pos)
	340	{
6823645d	341	struct list_head *e = &nf_ct_expect_list;
77ab9cff MJ	342	loff_t i;
	343
	344	/* strange seq_file api calls stop even if we fail,
	345	* thus we need to grab lock since stop unlocks */
	346	read_lock_bh(&nf_conntrack_lock);
	347
	348	if (list_empty(e))
	349	return NULL;
	350
	351	for (i = 0; i <= *pos; i++) {
	352	e = e->next;
6823645d	353	if (e == &nf_ct_expect_list)
77ab9cff MJ	354	return NULL;
	355	}
	356	return e;
	357	}
	358
	359	static void exp_seq_next(struct seq_file s, void v, loff_t pos)
	360	{
	361	struct list_head *e = v;
	362
	363	++*pos;
	364	e = e->next;
	365
6823645d	366	if (e == &nf_ct_expect_list)
77ab9cff MJ	367	return NULL;
	368
	369	return e;
	370	}
	371
	372	static void exp_seq_stop(struct seq_file s, void v)
	373	{
	374	read_unlock_bh(&nf_conntrack_lock);
	375	}
	376
	377	static int exp_seq_show(struct seq_file s, void v)
	378	{
	379	struct nf_conntrack_expect *expect = v;
	380
	381	if (expect->timeout.function)
	382	seq_printf(s, "%ld ", timer_pending(&expect->timeout)
	383	? (long)(expect->timeout.expires - jiffies)/HZ : 0);
	384	else
	385	seq_printf(s, "- ");
	386	seq_printf(s, "l3proto = %u proto=%u ",
	387	expect->tuple.src.l3num,
	388	expect->tuple.dst.protonum);
	389	print_tuple(s, &expect->tuple,
	390	__nf_ct_l3proto_find(expect->tuple.src.l3num),
605dcad6	391	__nf_ct_l4proto_find(expect->tuple.src.l3num,
77ab9cff MJ	392	expect->tuple.dst.protonum));
	393	return seq_putc(s, '\n');
	394	}
	395
	396	static struct seq_operations exp_seq_ops = {
	397	.start = exp_seq_start,
	398	.next = exp_seq_next,
	399	.stop = exp_seq_stop,
	400	.show = exp_seq_show
	401	};
	402
	403	static int exp_open(struct inode inode, struct file file)
	404	{
	405	return seq_open(file, &exp_seq_ops);
	406	}
	407
da7071d7	408	const struct file_operations exp_file_ops = {
77ab9cff MJ	409	.owner = THIS_MODULE,
	410	.open = exp_open,
	411	.read = seq_read,
	412	.llseek = seq_lseek,
	413	.release = seq_release
	414	};
	415	#endif /* CONFIG_PROC_FS */