[linux-2.6-block.git] / net / netfilter / nf_conntrack_proto_gre.c

/*
 * ip_conntrack_proto_gre.c - Version 3.0
 *
 * Connection tracking protocol helper module for GRE.
 *
 * GRE is a generic encapsulation protocol, which is generally not very
 * suited for NAT, as it has no protocol-specific part as port numbers.
 *
 * It has an optional key field, which may help us distinguishing two
 * connections between the same two hosts.
 *
 * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784
 *
 * PPTP is built on top of a modified version of GRE, and has a mandatory
 * field called "CallID", which serves us for the same purpose as the key
 * field in plain GRE.
 *
 * Documentation about PPTP can be found in RFC 2637
 *
 * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/in.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/dst.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <linux/netfilter/nf_conntrack_proto_gre.h>
#include <linux/netfilter/nf_conntrack_pptp.h>

#define GRE_TIMEOUT		(30 * HZ)
#define GRE_STREAM_TIMEOUT	(180 * HZ)

static int proto_gre_net_id __read_mostly;
struct netns_proto_gre {
	rwlock_t		keymap_lock;
	struct list_head	keymap_list;
};

void nf_ct_gre_keymap_flush(struct net *net)
{
	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
	struct nf_ct_gre_keymap *km, *tmp;

	write_lock_bh(&net_gre->keymap_lock);
	list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) {
		list_del(&km->list);
		kfree(km);
	}
	write_unlock_bh(&net_gre->keymap_lock);
}
EXPORT_SYMBOL(nf_ct_gre_keymap_flush);

static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km,
				const struct nf_conntrack_tuple *t)
{
	return km->tuple.src.l3num == t->src.l3num &&
	       !memcmp(&km->tuple.src.u3, &t->src.u3, sizeof(t->src.u3)) &&
	       !memcmp(&km->tuple.dst.u3, &t->dst.u3, sizeof(t->dst.u3)) &&
	       km->tuple.dst.protonum == t->dst.protonum &&
	       km->tuple.dst.u.all == t->dst.u.all;
}

/* look up the source key for a given tuple */
static __be16 gre_keymap_lookup(struct net *net, struct nf_conntrack_tuple *t)
{
	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
	struct nf_ct_gre_keymap *km;
	__be16 key = 0;

	read_lock_bh(&net_gre->keymap_lock);
	list_for_each_entry(km, &net_gre->keymap_list, list) {
		if (gre_key_cmpfn(km, t)) {
			key = km->tuple.src.u.gre.key;
			break;
		}
	}
	read_unlock_bh(&net_gre->keymap_lock);

	pr_debug("lookup src key 0x%x for ", key);
	nf_ct_dump_tuple(t);

	return key;
}

/* add a single keymap entry, associate with specified master ct */
int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
			 struct nf_conntrack_tuple *t)
{
	struct net *net = nf_ct_net(ct);
	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
	struct nf_conn_help *help = nfct_help(ct);
	struct nf_ct_gre_keymap **kmp, *km;

	kmp = &help->help.ct_pptp_info.keymap[dir];
	if (*kmp) {
		/* check whether it's a retransmission */
		read_lock_bh(&net_gre->keymap_lock);
		list_for_each_entry(km, &net_gre->keymap_list, list) {
			if (gre_key_cmpfn(km, t) && km == *kmp) {
				read_unlock_bh(&net_gre->keymap_lock);
				return 0;
			}
		}
		read_unlock_bh(&net_gre->keymap_lock);
		pr_debug("trying to override keymap_%s for ct %p\n",
			 dir == IP_CT_DIR_REPLY ? "reply" : "orig", ct);
		return -EEXIST;
	}

	km = kmalloc(sizeof(*km), GFP_ATOMIC);
	if (!km)
		return -ENOMEM;
	memcpy(&km->tuple, t, sizeof(*t));
	*kmp = km;

	pr_debug("adding new entry %p: ", km);
	nf_ct_dump_tuple(&km->tuple);

	write_lock_bh(&net_gre->keymap_lock);
	list_add_tail(&km->list, &net_gre->keymap_list);
	write_unlock_bh(&net_gre->keymap_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_add);

/* destroy the keymap entries associated with specified master ct */
void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
{
	struct net *net = nf_ct_net(ct);
	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
	struct nf_conn_help *help = nfct_help(ct);
	enum ip_conntrack_dir dir;

	pr_debug("entering for ct %p\n", ct);

	write_lock_bh(&net_gre->keymap_lock);
	for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
		if (help->help.ct_pptp_info.keymap[dir]) {
			pr_debug("removing %p from list\n",
				 help->help.ct_pptp_info.keymap[dir]);
			list_del(&help->help.ct_pptp_info.keymap[dir]->list);
			kfree(help->help.ct_pptp_info.keymap[dir]);
			help->help.ct_pptp_info.keymap[dir] = NULL;
		}
	}
	write_unlock_bh(&net_gre->keymap_lock);
}
EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_destroy);

/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */

/* invert gre part of tuple */
static bool gre_invert_tuple(struct nf_conntrack_tuple *tuple,
			     const struct nf_conntrack_tuple *orig)
{
	tuple->dst.u.gre.key = orig->src.u.gre.key;
	tuple->src.u.gre.key = orig->dst.u.gre.key;
	return true;
}

/* gre hdr info to tuple */
static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
			     struct nf_conntrack_tuple *tuple)
{
	struct net *net = dev_net(skb->dev ? skb->dev : skb_dst(skb)->dev);
	const struct gre_hdr_pptp *pgrehdr;
	struct gre_hdr_pptp _pgrehdr;
	__be16 srckey;
	const struct gre_hdr *grehdr;
	struct gre_hdr _grehdr;

	/* first only delinearize old RFC1701 GRE header */
	grehdr = skb_header_pointer(skb, dataoff, sizeof(_grehdr), &_grehdr);
	if (!grehdr || grehdr->version != GRE_VERSION_PPTP) {
		/* try to behave like "nf_conntrack_proto_generic" */
		tuple->src.u.all = 0;
		tuple->dst.u.all = 0;
		return true;
	}

	/* PPTP header is variable length, only need up to the call_id field */
	pgrehdr = skb_header_pointer(skb, dataoff, 8, &_pgrehdr);
	if (!pgrehdr)
		return true;

	if (ntohs(grehdr->protocol) != GRE_PROTOCOL_PPTP) {
		pr_debug("GRE_VERSION_PPTP but unknown proto\n");
		return false;
	}

	tuple->dst.u.gre.key = pgrehdr->call_id;
	srckey = gre_keymap_lookup(net, tuple);
	tuple->src.u.gre.key = srckey;

	return true;
}

/* print gre part of tuple */
static int gre_print_tuple(struct seq_file *s,
			   const struct nf_conntrack_tuple *tuple)
{
	return seq_printf(s, "srckey=0x%x dstkey=0x%x ",
			  ntohs(tuple->src.u.gre.key),
			  ntohs(tuple->dst.u.gre.key));
}

/* print private data for conntrack */
static int gre_print_conntrack(struct seq_file *s, struct nf_conn *ct)
{
	return seq_printf(s, "timeout=%u, stream_timeout=%u ",
			  (ct->proto.gre.timeout / HZ),
			  (ct->proto.gre.stream_timeout / HZ));
}

/* Returns verdict for packet, and may modify conntrack */
static int gre_packet(struct nf_conn *ct,
		      const struct sk_buff *skb,
		      unsigned int dataoff,
		      enum ip_conntrack_info ctinfo,
		      u_int8_t pf,
		      unsigned int hooknum)
{
	/* If we've seen traffic both ways, this is a GRE connection.
	 * Extend timeout. */
	if (ct->status & IPS_SEEN_REPLY) {
		nf_ct_refresh_acct(ct, ctinfo, skb,
				   ct->proto.gre.stream_timeout);
		/* Also, more likely to be important, and not a probe. */
		set_bit(IPS_ASSURED_BIT, &ct->status);
		nf_conntrack_event_cache(IPCT_ASSURED, ct);
	} else
		nf_ct_refresh_acct(ct, ctinfo, skb,
				   ct->proto.gre.timeout);

	return NF_ACCEPT;
}

/* Called when a new connection for this protocol found. */
static bool gre_new(struct nf_conn *ct, const struct sk_buff *skb,
		    unsigned int dataoff)
{
	pr_debug(": ");
	nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);

	/* initialize to sane value.  Ideally a conntrack helper
	 * (e.g. in case of pptp) is increasing them */
	ct->proto.gre.stream_timeout = GRE_STREAM_TIMEOUT;
	ct->proto.gre.timeout = GRE_TIMEOUT;

	return true;
}

/* Called when a conntrack entry has already been removed from the hashes
 * and is about to be deleted from memory */
static void gre_destroy(struct nf_conn *ct)
{
	struct nf_conn *master = ct->master;
	pr_debug(" entering\n");

	if (!master)
		pr_debug("no master !?!\n");
	else
		nf_ct_gre_keymap_destroy(master);
}

/* protocol helper struct */
static struct nf_conntrack_l4proto nf_conntrack_l4proto_gre4 __read_mostly = {
	.l3proto	 = AF_INET,
	.l4proto	 = IPPROTO_GRE,
	.name		 = "gre",
	.pkt_to_tuple	 = gre_pkt_to_tuple,
	.invert_tuple	 = gre_invert_tuple,
	.print_tuple	 = gre_print_tuple,
	.print_conntrack = gre_print_conntrack,
	.packet		 = gre_packet,
	.new		 = gre_new,
	.destroy	 = gre_destroy,
	.me 		 = THIS_MODULE,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
	.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
	.nla_policy	 = nf_ct_port_nla_policy,
#endif
};

static int proto_gre_net_init(struct net *net)
{
	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);

	rwlock_init(&net_gre->keymap_lock);
	INIT_LIST_HEAD(&net_gre->keymap_list);

	return 0;
}

static void proto_gre_net_exit(struct net *net)
{
	nf_ct_gre_keymap_flush(net);
}

static struct pernet_operations proto_gre_net_ops = {
	.init = proto_gre_net_init,
	.exit = proto_gre_net_exit,
	.id   = &proto_gre_net_id,
	.size = sizeof(struct netns_proto_gre),
};

static int __init nf_ct_proto_gre_init(void)
{
	int rv;

	rv = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_gre4);
	if (rv < 0)
		return rv;
	rv = register_pernet_subsys(&proto_gre_net_ops);
	if (rv < 0)
		nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
	return rv;
}

static void __exit nf_ct_proto_gre_fini(void)
{
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
	unregister_pernet_subsys(&proto_gre_net_ops);
}

module_init(nf_ct_proto_gre_init);
module_exit(nf_ct_proto_gre_fini);

MODULE_LICENSE("GPL");
Commit	Line	Data
f09943fe PM	1	/*
	2	* ip_conntrack_proto_gre.c - Version 3.0
	3	*
	4	* Connection tracking protocol helper module for GRE.
	5	*
	6	* GRE is a generic encapsulation protocol, which is generally not very
	7	* suited for NAT, as it has no protocol-specific part as port numbers.
	8	*
	9	* It has an optional key field, which may help us distinguishing two
	10	* connections between the same two hosts.
	11	*
	12	* GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784
	13	*
	14	* PPTP is built on top of a modified version of GRE, and has a mandatory
	15	* field called "CallID", which serves us for the same purpose as the key
	16	* field in plain GRE.
	17	*
	18	* Documentation about PPTP can be found in RFC 2637
	19	*
	20	* (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
	21	*
	22	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	23	*
	24	*/
	25
	26	#include <linux/module.h>
	27	#include <linux/types.h>
	28	#include <linux/timer.h>
	29	#include <linux/list.h>
	30	#include <linux/seq_file.h>
	31	#include <linux/in.h>
3bb0d1c0	32	#include <linux/netdevice.h>
f09943fe	33	#include <linux/skbuff.h>
5a0e3ad6	34	#include <linux/slab.h>
3bb0d1c0 AD	35	#include <net/dst.h>
	36	#include <net/net_namespace.h>
	37	#include <net/netns/generic.h>
f09943fe PM	38	#include <net/netfilter/nf_conntrack_l4proto.h>
	39	#include <net/netfilter/nf_conntrack_helper.h>
	40	#include <net/netfilter/nf_conntrack_core.h>
	41	#include <linux/netfilter/nf_conntrack_proto_gre.h>
	42	#include <linux/netfilter/nf_conntrack_pptp.h>
	43
	44	#define GRE_TIMEOUT (30 * HZ)
	45	#define GRE_STREAM_TIMEOUT (180 * HZ)
	46
f99189b1	47	static int proto_gre_net_id __read_mostly;
3bb0d1c0 AD	48	struct netns_proto_gre {
	49	rwlock_t keymap_lock;
	50	struct list_head keymap_list;
	51	};
f09943fe	52
3bb0d1c0	53	void nf_ct_gre_keymap_flush(struct net *net)
f09943fe	54	{
3bb0d1c0	55	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
51807e91	56	struct nf_ct_gre_keymap km, tmp;
f09943fe	57
3bb0d1c0 AD	58	write_lock_bh(&net_gre->keymap_lock);
3bb0d1c0 AD	59	list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) {
51807e91 AD	60	list_del(&km->list);
51807e91 AD	61	kfree(km);
f09943fe	62	}
3bb0d1c0	63	write_unlock_bh(&net_gre->keymap_lock);
f09943fe PM	64	}
	65	EXPORT_SYMBOL(nf_ct_gre_keymap_flush);
	66
	67	static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km,
	68	const struct nf_conntrack_tuple *t)
	69	{
	70	return km->tuple.src.l3num == t->src.l3num &&
	71	!memcmp(&km->tuple.src.u3, &t->src.u3, sizeof(t->src.u3)) &&
	72	!memcmp(&km->tuple.dst.u3, &t->dst.u3, sizeof(t->dst.u3)) &&
	73	km->tuple.dst.protonum == t->dst.protonum &&
	74	km->tuple.dst.u.all == t->dst.u.all;
	75	}
	76
	77	/* look up the source key for a given tuple */
3bb0d1c0	78	static __be16 gre_keymap_lookup(struct net net, struct nf_conntrack_tuple t)
f09943fe	79	{
3bb0d1c0	80	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
f09943fe PM	81	struct nf_ct_gre_keymap *km;
	82	__be16 key = 0;
	83
3bb0d1c0 AD	84	read_lock_bh(&net_gre->keymap_lock);
3bb0d1c0 AD	85	list_for_each_entry(km, &net_gre->keymap_list, list) {
f09943fe PM	86	if (gre_key_cmpfn(km, t)) {
	87	key = km->tuple.src.u.gre.key;
	88	break;
	89	}
	90	}
3bb0d1c0	91	read_unlock_bh(&net_gre->keymap_lock);
f09943fe	92
0d53778e	93	pr_debug("lookup src key 0x%x for ", key);
3c9fba65	94	nf_ct_dump_tuple(t);
f09943fe PM	95
	96	return key;
	97	}
	98
	99	/* add a single keymap entry, associate with specified master ct */
	100	int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
	101	struct nf_conntrack_tuple *t)
	102	{
3bb0d1c0 AD	103	struct net *net = nf_ct_net(ct);
3bb0d1c0 AD	104	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
f09943fe PM	105	struct nf_conn_help *help = nfct_help(ct);
	106	struct nf_ct_gre_keymap *kmp, km;
	107
f09943fe PM	108	kmp = &help->help.ct_pptp_info.keymap[dir];
	109	if (*kmp) {
	110	/* check whether it's a retransmission */
3bb0d1c0 AD	111	read_lock_bh(&net_gre->keymap_lock);
3bb0d1c0 AD	112	list_for_each_entry(km, &net_gre->keymap_list, list) {
887464a4	113	if (gre_key_cmpfn(km, t) && km == *kmp) {
3bb0d1c0	114	read_unlock_bh(&net_gre->keymap_lock);
f09943fe	115	return 0;
887464a4	116	}
f09943fe	117	}
3bb0d1c0	118	read_unlock_bh(&net_gre->keymap_lock);
0d53778e PM	119	pr_debug("trying to override keymap_%s for ct %p\n",
0d53778e PM	120	dir == IP_CT_DIR_REPLY ? "reply" : "orig", ct);
f09943fe PM	121	return -EEXIST;
	122	}
	123
	124	km = kmalloc(sizeof(*km), GFP_ATOMIC);
	125	if (!km)
	126	return -ENOMEM;
	127	memcpy(&km->tuple, t, sizeof(*t));
	128	*kmp = km;
	129
0d53778e	130	pr_debug("adding new entry %p: ", km);
3c9fba65	131	nf_ct_dump_tuple(&km->tuple);
f09943fe	132
3bb0d1c0 AD	133	write_lock_bh(&net_gre->keymap_lock);
	134	list_add_tail(&km->list, &net_gre->keymap_list);
	135	write_unlock_bh(&net_gre->keymap_lock);
f09943fe PM	136
	137	return 0;
	138	}
	139	EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_add);
	140
	141	/* destroy the keymap entries associated with specified master ct */
	142	void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
	143	{
3bb0d1c0 AD	144	struct net *net = nf_ct_net(ct);
3bb0d1c0 AD	145	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
f09943fe PM	146	struct nf_conn_help *help = nfct_help(ct);
	147	enum ip_conntrack_dir dir;
	148
0d53778e	149	pr_debug("entering for ct %p\n", ct);
f09943fe	150
3bb0d1c0	151	write_lock_bh(&net_gre->keymap_lock);
f09943fe PM	152	for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
f09943fe PM	153	if (help->help.ct_pptp_info.keymap[dir]) {
0d53778e PM	154	pr_debug("removing %p from list\n",
0d53778e PM	155	help->help.ct_pptp_info.keymap[dir]);
f09943fe PM	156	list_del(&help->help.ct_pptp_info.keymap[dir]->list);
	157	kfree(help->help.ct_pptp_info.keymap[dir]);
	158	help->help.ct_pptp_info.keymap[dir] = NULL;
	159	}
	160	}
3bb0d1c0	161	write_unlock_bh(&net_gre->keymap_lock);
f09943fe PM	162	}
	163	EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_destroy);
	164
	165	/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */
	166
	167	/* invert gre part of tuple */
09f263cd JE	168	static bool gre_invert_tuple(struct nf_conntrack_tuple *tuple,
09f263cd JE	169	const struct nf_conntrack_tuple *orig)
f09943fe PM	170	{
	171	tuple->dst.u.gre.key = orig->src.u.gre.key;
	172	tuple->src.u.gre.key = orig->dst.u.gre.key;
09f263cd	173	return true;
f09943fe PM	174	}
	175
	176	/* gre hdr info to tuple */
09f263cd JE	177	static bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
09f263cd JE	178	struct nf_conntrack_tuple *tuple)
f09943fe	179	{
adf30907	180	struct net *net = dev_net(skb->dev ? skb->dev : skb_dst(skb)->dev);
dc35dc5a JE	181	const struct gre_hdr_pptp *pgrehdr;
dc35dc5a JE	182	struct gre_hdr_pptp _pgrehdr;
f09943fe	183	__be16 srckey;
dc35dc5a JE	184	const struct gre_hdr *grehdr;
dc35dc5a JE	185	struct gre_hdr _grehdr;
f09943fe PM	186
	187	/* first only delinearize old RFC1701 GRE header */
	188	grehdr = skb_header_pointer(skb, dataoff, sizeof(_grehdr), &_grehdr);
	189	if (!grehdr \|\| grehdr->version != GRE_VERSION_PPTP) {
	190	/* try to behave like "nf_conntrack_proto_generic" */
	191	tuple->src.u.all = 0;
	192	tuple->dst.u.all = 0;
09f263cd	193	return true;
f09943fe PM	194	}
	195
	196	/* PPTP header is variable length, only need up to the call_id field */
	197	pgrehdr = skb_header_pointer(skb, dataoff, 8, &_pgrehdr);
	198	if (!pgrehdr)
09f263cd	199	return true;
f09943fe PM	200
f09943fe PM	201	if (ntohs(grehdr->protocol) != GRE_PROTOCOL_PPTP) {
0d53778e	202	pr_debug("GRE_VERSION_PPTP but unknown proto\n");
09f263cd	203	return false;
f09943fe PM	204	}
	205
	206	tuple->dst.u.gre.key = pgrehdr->call_id;
3bb0d1c0	207	srckey = gre_keymap_lookup(net, tuple);
f09943fe PM	208	tuple->src.u.gre.key = srckey;
f09943fe PM	209
09f263cd	210	return true;
f09943fe PM	211	}
	212
	213	/* print gre part of tuple */
	214	static int gre_print_tuple(struct seq_file *s,
	215	const struct nf_conntrack_tuple *tuple)
	216	{
	217	return seq_printf(s, "srckey=0x%x dstkey=0x%x ",
	218	ntohs(tuple->src.u.gre.key),
	219	ntohs(tuple->dst.u.gre.key));
	220	}
	221
	222	/* print private data for conntrack */
440f0d58	223	static int gre_print_conntrack(struct seq_file s, struct nf_conn ct)
f09943fe PM	224	{
	225	return seq_printf(s, "timeout=%u, stream_timeout=%u ",
	226	(ct->proto.gre.timeout / HZ),
	227	(ct->proto.gre.stream_timeout / HZ));
	228	}
	229
	230	/* Returns verdict for packet, and may modify conntrack */
	231	static int gre_packet(struct nf_conn *ct,
	232	const struct sk_buff *skb,
	233	unsigned int dataoff,
	234	enum ip_conntrack_info ctinfo,
76108cea	235	u_int8_t pf,
f09943fe PM	236	unsigned int hooknum)
	237	{
	238	/* If we've seen traffic both ways, this is a GRE connection.
	239	* Extend timeout. */
	240	if (ct->status & IPS_SEEN_REPLY) {
	241	nf_ct_refresh_acct(ct, ctinfo, skb,
	242	ct->proto.gre.stream_timeout);
	243	/* Also, more likely to be important, and not a probe. */
	244	set_bit(IPS_ASSURED_BIT, &ct->status);
858b3133	245	nf_conntrack_event_cache(IPCT_ASSURED, ct);
f09943fe PM	246	} else
	247	nf_ct_refresh_acct(ct, ctinfo, skb,
	248	ct->proto.gre.timeout);
	249
	250	return NF_ACCEPT;
	251	}
	252
	253	/* Called when a new connection for this protocol found. */
09f263cd JE	254	static bool gre_new(struct nf_conn ct, const struct sk_buff skb,
09f263cd JE	255	unsigned int dataoff)
f09943fe	256	{
0d53778e	257	pr_debug(": ");
3c9fba65	258	nf_ct_dump_tuple(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
f09943fe PM	259
	260	/* initialize to sane value. Ideally a conntrack helper
	261	* (e.g. in case of pptp) is increasing them */
	262	ct->proto.gre.stream_timeout = GRE_STREAM_TIMEOUT;
	263	ct->proto.gre.timeout = GRE_TIMEOUT;
	264
09f263cd	265	return true;
f09943fe PM	266	}
	267
	268	/* Called when a conntrack entry has already been removed from the hashes
	269	* and is about to be deleted from memory */
	270	static void gre_destroy(struct nf_conn *ct)
	271	{
	272	struct nf_conn *master = ct->master;
0d53778e	273	pr_debug(" entering\n");
f09943fe PM	274
f09943fe PM	275	if (!master)
0d53778e	276	pr_debug("no master !?!\n");
f09943fe PM	277	else
	278	nf_ct_gre_keymap_destroy(master);
	279	}
	280
	281	/* protocol helper struct */
61075af5	282	static struct nf_conntrack_l4proto nf_conntrack_l4proto_gre4 __read_mostly = {
f09943fe PM	283	.l3proto = AF_INET,
	284	.l4proto = IPPROTO_GRE,
	285	.name = "gre",
	286	.pkt_to_tuple = gre_pkt_to_tuple,
	287	.invert_tuple = gre_invert_tuple,
	288	.print_tuple = gre_print_tuple,
	289	.print_conntrack = gre_print_conntrack,
	290	.packet = gre_packet,
	291	.new = gre_new,
	292	.destroy = gre_destroy,
	293	.me = THIS_MODULE,
e281db5c	294	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832	295	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e	296	.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
fdf70832	297	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	298	.nla_policy = nf_ct_port_nla_policy,
f09943fe PM	299	#endif
	300	};
	301
3bb0d1c0 AD	302	static int proto_gre_net_init(struct net *net)
3bb0d1c0 AD	303	{
e8d02885	304	struct netns_proto_gre *net_gre = net_generic(net, proto_gre_net_id);
3bb0d1c0	305
3bb0d1c0 AD	306	rwlock_init(&net_gre->keymap_lock);
	307	INIT_LIST_HEAD(&net_gre->keymap_list);
	308
e8d02885	309	return 0;
3bb0d1c0 AD	310	}
	311
	312	static void proto_gre_net_exit(struct net *net)
	313	{
3bb0d1c0	314	nf_ct_gre_keymap_flush(net);
3bb0d1c0 AD	315	}
	316
	317	static struct pernet_operations proto_gre_net_ops = {
	318	.init = proto_gre_net_init,
	319	.exit = proto_gre_net_exit,
e8d02885 EB	320	.id = &proto_gre_net_id,
e8d02885 EB	321	.size = sizeof(struct netns_proto_gre),
3bb0d1c0 AD	322	};
3bb0d1c0 AD	323
f09943fe PM	324	static int __init nf_ct_proto_gre_init(void)
f09943fe PM	325	{
3bb0d1c0 AD	326	int rv;
	327
	328	rv = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_gre4);
	329	if (rv < 0)
	330	return rv;
e8d02885	331	rv = register_pernet_subsys(&proto_gre_net_ops);
3bb0d1c0 AD	332	if (rv < 0)
	333	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
	334	return rv;
f09943fe PM	335	}
f09943fe PM	336
56bc0f96	337	static void __exit nf_ct_proto_gre_fini(void)
f09943fe PM	338	{
f09943fe PM	339	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_gre4);
e8d02885	340	unregister_pernet_subsys(&proto_gre_net_ops);
f09943fe PM	341	}
	342
	343	module_init(nf_ct_proto_gre_init);
	344	module_exit(nf_ct_proto_gre_fini);
	345
	346	MODULE_LICENSE("GPL");