[mirror_ubuntu-artful-kernel.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 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_ct_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_ct_expect_list, list) {
		if (expect_matches(i, exp) && del_timer(&i->timeout)) {
			nf_ct_unlink_expect(i);
			write_unlock_bh(&nf_conntrack_lock);
			nf_ct_expect_put(i);
			return;
		}
	}
	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;
	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_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 */
	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. */
6823645d	175	void nf_ct_unexpect_related(struct nf_conntrack_expect *exp)
77ab9cff MJ	176	{
	177	struct nf_conntrack_expect *i;
	178
	179	write_lock_bh(&nf_conntrack_lock);
59c51591	180	/* choose the oldest expectation to evict */
6823645d	181	list_for_each_entry_reverse(i, &nf_ct_expect_list, list) {
77ab9cff MJ	182	if (expect_matches(i, exp) && del_timer(&i->timeout)) {
	183	nf_ct_unlink_expect(i);
	184	write_unlock_bh(&nf_conntrack_lock);
6823645d	185	nf_ct_expect_put(i);
77ab9cff MJ	186	return;
	187	}
	188	}
	189	write_unlock_bh(&nf_conntrack_lock);
	190	}
6823645d	191	EXPORT_SYMBOL_GPL(nf_ct_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 */
6823645d	196	struct nf_conntrack_expect nf_ct_expect_alloc(struct nf_conn me)
77ab9cff MJ	197	{
	198	struct nf_conntrack_expect *new;
	199
6823645d	200	new = kmem_cache_alloc(nf_ct_expect_cachep, GFP_ATOMIC);
77ab9cff MJ	201	if (!new)
	202	return NULL;
	203
	204	new->master = me;
	205	atomic_set(&new->use, 1);
	206	return new;
	207	}
6823645d	208	EXPORT_SYMBOL_GPL(nf_ct_expect_alloc);
77ab9cff	209
6823645d PM	210	void nf_ct_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)
d6a9b650 PM	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	}
6823645d	276	EXPORT_SYMBOL_GPL(nf_ct_expect_init);
d6a9b650	277
6823645d	278	void nf_ct_expect_put(struct nf_conntrack_expect *exp)
77ab9cff MJ	279	{
77ab9cff MJ	280	if (atomic_dec_and_test(&exp->use))
6823645d	281	kmem_cache_free(nf_ct_expect_cachep, exp);
77ab9cff	282	}
6823645d	283	EXPORT_SYMBOL_GPL(nf_ct_expect_put);
77ab9cff	284
6823645d	285	static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
77ab9cff MJ	286	{
	287	struct nf_conn_help *master_help = nfct_help(exp->master);
	288
	289	atomic_inc(&exp->use);
	290	master_help->expecting++;
6823645d	291	list_add(&exp->list, &nf_ct_expect_list);
77ab9cff	292
6823645d PM	293	setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
6823645d PM	294	(unsigned long)exp);
77ab9cff MJ	295	exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
	296	add_timer(&exp->timeout);
	297
6823645d	298	exp->id = ++nf_ct_expect_next_id;
77ab9cff MJ	299	atomic_inc(&exp->use);
	300	NF_CT_STAT_INC(expect_create);
	301	}
	302
	303	/* Race with expectations being used means we could have none to find; OK. */
	304	static void evict_oldest_expect(struct nf_conn *master)
	305	{
	306	struct nf_conntrack_expect *i;
	307
6823645d	308	list_for_each_entry_reverse(i, &nf_ct_expect_list, list) {
77ab9cff MJ	309	if (i->master == master) {
	310	if (del_timer(&i->timeout)) {
	311	nf_ct_unlink_expect(i);
6823645d	312	nf_ct_expect_put(i);
77ab9cff MJ	313	}
	314	break;
	315	}
	316	}
	317	}
	318
	319	static inline int refresh_timer(struct nf_conntrack_expect *i)
	320	{
	321	struct nf_conn_help *master_help = nfct_help(i->master);
	322
	323	if (!del_timer(&i->timeout))
	324	return 0;
	325
	326	i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
	327	add_timer(&i->timeout);
	328	return 1;
	329	}
	330
6823645d	331	int nf_ct_expect_related(struct nf_conntrack_expect *expect)
77ab9cff MJ	332	{
	333	struct nf_conntrack_expect *i;
	334	struct nf_conn *master = expect->master;
	335	struct nf_conn_help *master_help = nfct_help(master);
	336	int ret;
	337
	338	NF_CT_ASSERT(master_help);
	339
	340	write_lock_bh(&nf_conntrack_lock);
3c158f7f PM	341	if (!master_help->helper) {
	342	ret = -ESHUTDOWN;
	343	goto out;
	344	}
6823645d	345	list_for_each_entry(i, &nf_ct_expect_list, list) {
77ab9cff MJ	346	if (expect_matches(i, expect)) {
	347	/* Refresh timer: if it's dying, ignore.. */
	348	if (refresh_timer(i)) {
	349	ret = 0;
	350	goto out;
	351	}
	352	} else if (expect_clash(i, expect)) {
	353	ret = -EBUSY;
	354	goto out;
	355	}
	356	}
	357	/* Will be over limit? */
	358	if (master_help->helper->max_expected &&
	359	master_help->expecting >= master_help->helper->max_expected)
	360	evict_oldest_expect(master);
	361
6823645d PM	362	nf_ct_expect_insert(expect);
6823645d PM	363	nf_ct_expect_event(IPEXP_NEW, expect);
77ab9cff MJ	364	ret = 0;
	365	out:
	366	write_unlock_bh(&nf_conntrack_lock);
	367	return ret;
	368	}
6823645d	369	EXPORT_SYMBOL_GPL(nf_ct_expect_related);
77ab9cff MJ	370
	371	#ifdef CONFIG_PROC_FS
	372	static void exp_seq_start(struct seq_file s, loff_t *pos)
	373	{
6823645d	374	struct list_head *e = &nf_ct_expect_list;
77ab9cff MJ	375	loff_t i;
	376
	377	/* strange seq_file api calls stop even if we fail,
	378	* thus we need to grab lock since stop unlocks */
	379	read_lock_bh(&nf_conntrack_lock);
	380
	381	if (list_empty(e))
	382	return NULL;
	383
	384	for (i = 0; i <= *pos; i++) {
	385	e = e->next;
6823645d	386	if (e == &nf_ct_expect_list)
77ab9cff MJ	387	return NULL;
	388	}
	389	return e;
	390	}
	391
	392	static void exp_seq_next(struct seq_file s, void v, loff_t pos)
	393	{
	394	struct list_head *e = v;
	395
	396	++*pos;
	397	e = e->next;
	398
6823645d	399	if (e == &nf_ct_expect_list)
77ab9cff MJ	400	return NULL;
	401
	402	return e;
	403	}
	404
	405	static void exp_seq_stop(struct seq_file s, void v)
	406	{
	407	read_unlock_bh(&nf_conntrack_lock);
	408	}
	409
	410	static int exp_seq_show(struct seq_file s, void v)
	411	{
	412	struct nf_conntrack_expect *expect = v;
	413
	414	if (expect->timeout.function)
	415	seq_printf(s, "%ld ", timer_pending(&expect->timeout)
	416	? (long)(expect->timeout.expires - jiffies)/HZ : 0);
	417	else
	418	seq_printf(s, "- ");
	419	seq_printf(s, "l3proto = %u proto=%u ",
	420	expect->tuple.src.l3num,
	421	expect->tuple.dst.protonum);
	422	print_tuple(s, &expect->tuple,
	423	__nf_ct_l3proto_find(expect->tuple.src.l3num),
605dcad6	424	__nf_ct_l4proto_find(expect->tuple.src.l3num,
77ab9cff MJ	425	expect->tuple.dst.protonum));
	426	return seq_putc(s, '\n');
	427	}
	428
	429	static struct seq_operations exp_seq_ops = {
	430	.start = exp_seq_start,
	431	.next = exp_seq_next,
	432	.stop = exp_seq_stop,
	433	.show = exp_seq_show
	434	};
	435
	436	static int exp_open(struct inode inode, struct file file)
	437	{
	438	return seq_open(file, &exp_seq_ops);
	439	}
	440
da7071d7	441	const struct file_operations exp_file_ops = {
77ab9cff MJ	442	.owner = THIS_MODULE,
	443	.open = exp_open,
	444	.read = seq_read,
	445	.llseek = seq_lseek,
	446	.release = seq_release
	447	};
	448	#endif /* CONFIG_PROC_FS */