[mirror_ubuntu-hirsute-kernel.git] / net / netfilter / nf_conntrack_proto_gre.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/)
 *
 * (C) 2006-2012 Patrick McHardy <kaber@trash.net>
 */

#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 <net/netfilter/nf_conntrack_timeout.h>
#include <linux/netfilter/nf_conntrack_proto_gre.h>
#include <linux/netfilter/nf_conntrack_pptp.h>

static const unsigned int gre_timeouts[GRE_CT_MAX] = {
	[GRE_CT_UNREPLIED]	= 30*HZ,
	[GRE_CT_REPLIED]	= 180*HZ,
};

/* used when expectation is added */
static DEFINE_SPINLOCK(keymap_lock);

static inline struct nf_gre_net *gre_pernet(struct net *net)
{
	return &net->ct.nf_ct_proto.gre;
}

void nf_ct_gre_keymap_flush(struct net *net)
{
	struct nf_gre_net *net_gre = gre_pernet(net);
	struct nf_ct_gre_keymap *km, *tmp;

	spin_lock_bh(&keymap_lock);
	list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) {
		list_del_rcu(&km->list);
		kfree_rcu(km, rcu);
	}
	spin_unlock_bh(&keymap_lock);
}

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 nf_gre_net *net_gre = gre_pernet(net);
	struct nf_ct_gre_keymap *km;
	__be16 key = 0;

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

	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 nf_gre_net *net_gre = gre_pernet(net);
	struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
	struct nf_ct_gre_keymap **kmp, *km;

	kmp = &ct_pptp_info->keymap[dir];
	if (*kmp) {
		/* check whether it's a retransmission */
		list_for_each_entry_rcu(km, &net_gre->keymap_list, list) {
			if (gre_key_cmpfn(km, t) && km == *kmp)
				return 0;
		}
		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);

	spin_lock_bh(&keymap_lock);
	list_add_tail(&km->list, &net_gre->keymap_list);
	spin_unlock_bh(&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 nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
	enum ip_conntrack_dir dir;

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

	spin_lock_bh(&keymap_lock);
	for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
		if (ct_pptp_info->keymap[dir]) {
			pr_debug("removing %p from list\n",
				 ct_pptp_info->keymap[dir]);
			list_del_rcu(&ct_pptp_info->keymap[dir]->list);
			kfree_rcu(ct_pptp_info->keymap[dir], rcu);
			ct_pptp_info->keymap[dir] = NULL;
		}
	}
	spin_unlock_bh(&keymap_lock);
}
EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_destroy);

/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */

/* gre hdr info to tuple */
bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
		      struct net *net, struct nf_conntrack_tuple *tuple)
{
	const struct pptp_gre_header *pgrehdr;
	struct pptp_gre_header _pgrehdr;
	__be16 srckey;
	const struct gre_base_hdr *grehdr;
	struct gre_base_hdr _grehdr;

	/* first only delinearize old RFC1701 GRE header */
	grehdr = skb_header_pointer(skb, dataoff, sizeof(_grehdr), &_grehdr);
	if (!grehdr || (grehdr->flags & GRE_VERSION) != GRE_VERSION_1) {
		/* 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 (grehdr->protocol != GRE_PROTO_PPP) {
		pr_debug("Unsupported GRE proto(0x%x)\n", ntohs(grehdr->protocol));
		return false;
	}

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

	return true;
}

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

static unsigned int *gre_get_timeouts(struct net *net)
{
	return gre_pernet(net)->timeouts;
}

/* Returns verdict for packet, and may modify conntrack */
int nf_conntrack_gre_packet(struct nf_conn *ct,
			    struct sk_buff *skb,
			    unsigned int dataoff,
			    enum ip_conntrack_info ctinfo,
			    const struct nf_hook_state *state)
{
	if (state->pf != NFPROTO_IPV4)
		return -NF_ACCEPT;

	if (!nf_ct_is_confirmed(ct)) {
		unsigned int *timeouts = nf_ct_timeout_lookup(ct);

		if (!timeouts)
			timeouts = gre_get_timeouts(nf_ct_net(ct));

		/* initialize to sane value.  Ideally a conntrack helper
		 * (e.g. in case of pptp) is increasing them */
		ct->proto.gre.stream_timeout = timeouts[GRE_CT_REPLIED];
		ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED];
	}

	/* 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. */
		if (!test_and_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;
}

#ifdef CONFIG_NF_CONNTRACK_TIMEOUT

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_cttimeout.h>

static int gre_timeout_nlattr_to_obj(struct nlattr *tb[],
				     struct net *net, void *data)
{
	unsigned int *timeouts = data;
	struct nf_gre_net *net_gre = gre_pernet(net);

	if (!timeouts)
		timeouts = gre_get_timeouts(net);
	/* set default timeouts for GRE. */
	timeouts[GRE_CT_UNREPLIED] = net_gre->timeouts[GRE_CT_UNREPLIED];
	timeouts[GRE_CT_REPLIED] = net_gre->timeouts[GRE_CT_REPLIED];

	if (tb[CTA_TIMEOUT_GRE_UNREPLIED]) {
		timeouts[GRE_CT_UNREPLIED] =
			ntohl(nla_get_be32(tb[CTA_TIMEOUT_GRE_UNREPLIED])) * HZ;
	}
	if (tb[CTA_TIMEOUT_GRE_REPLIED]) {
		timeouts[GRE_CT_REPLIED] =
			ntohl(nla_get_be32(tb[CTA_TIMEOUT_GRE_REPLIED])) * HZ;
	}
	return 0;
}

static int
gre_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
{
	const unsigned int *timeouts = data;

	if (nla_put_be32(skb, CTA_TIMEOUT_GRE_UNREPLIED,
			 htonl(timeouts[GRE_CT_UNREPLIED] / HZ)) ||
	    nla_put_be32(skb, CTA_TIMEOUT_GRE_REPLIED,
			 htonl(timeouts[GRE_CT_REPLIED] / HZ)))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -ENOSPC;
}

static const struct nla_policy
gre_timeout_nla_policy[CTA_TIMEOUT_GRE_MAX+1] = {
	[CTA_TIMEOUT_GRE_UNREPLIED]	= { .type = NLA_U32 },
	[CTA_TIMEOUT_GRE_REPLIED]	= { .type = NLA_U32 },
};
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */

void nf_conntrack_gre_init_net(struct net *net)
{
	struct nf_gre_net *net_gre = gre_pernet(net);
	int i;

	INIT_LIST_HEAD(&net_gre->keymap_list);
	for (i = 0; i < GRE_CT_MAX; i++)
		net_gre->timeouts[i] = gre_timeouts[i];
}

/* protocol helper struct */
const struct nf_conntrack_l4proto nf_conntrack_l4proto_gre = {
	.l4proto	 = IPPROTO_GRE,
#ifdef CONFIG_NF_CONNTRACK_PROCFS
	.print_conntrack = gre_print_conntrack,
#endif
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	.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
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
	.ctnl_timeout    = {
		.nlattr_to_obj	= gre_timeout_nlattr_to_obj,
		.obj_to_nlattr	= gre_timeout_obj_to_nlattr,
		.nlattr_max	= CTA_TIMEOUT_GRE_MAX,
		.obj_size	= sizeof(unsigned int) * GRE_CT_MAX,
		.nla_policy	= gre_timeout_nla_policy,
	},
#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
};
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
f09943fe	2	/*
f09943fe PM	3	* Connection tracking protocol helper module for GRE.
	4	*
	5	* GRE is a generic encapsulation protocol, which is generally not very
	6	* suited for NAT, as it has no protocol-specific part as port numbers.
	7	*
	8	* It has an optional key field, which may help us distinguishing two
	9	* connections between the same two hosts.
	10	*
	11	* GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784
	12	*
	13	* PPTP is built on top of a modified version of GRE, and has a mandatory
	14	* field called "CallID", which serves us for the same purpose as the key
	15	* field in plain GRE.
	16	*
	17	* Documentation about PPTP can be found in RFC 2637
	18	*
	19	* (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
	20	*
	21	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	22	*
f229f6ce	23	* (C) 2006-2012 Patrick McHardy <kaber@trash.net>
f09943fe PM	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>
c779e849	41	#include <net/netfilter/nf_conntrack_timeout.h>
f09943fe PM	42	#include <linux/netfilter/nf_conntrack_proto_gre.h>
	43	#include <linux/netfilter/nf_conntrack_pptp.h>
	44
2c9e8637	45	static const unsigned int gre_timeouts[GRE_CT_MAX] = {
b888341c PNA	46	[GRE_CT_UNREPLIED] = 30*HZ,
	47	[GRE_CT_REPLIED] = 180*HZ,
	48	};
f09943fe	49
202e651c FW	50	/* used when expectation is added */
202e651c FW	51	static DEFINE_SPINLOCK(keymap_lock);
f09943fe	52
22fc4c4c	53	static inline struct nf_gre_net gre_pernet(struct net net)
4f71d80f	54	{
22fc4c4c	55	return &net->ct.nf_ct_proto.gre;
4f71d80f G	56	}
4f71d80f G	57
22fc4c4c	58	void nf_ct_gre_keymap_flush(struct net *net)
f09943fe	59	{
22fc4c4c	60	struct nf_gre_net *net_gre = gre_pernet(net);
51807e91	61	struct nf_ct_gre_keymap km, tmp;
f09943fe	62
202e651c	63	spin_lock_bh(&keymap_lock);
3bb0d1c0	64	list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) {
202e651c FW	65	list_del_rcu(&km->list);
202e651c FW	66	kfree_rcu(km, rcu);
f09943fe	67	}
202e651c	68	spin_unlock_bh(&keymap_lock);
f09943fe	69	}
f09943fe PM	70
	71	static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km,
	72	const struct nf_conntrack_tuple *t)
	73	{
	74	return km->tuple.src.l3num == t->src.l3num &&
	75	!memcmp(&km->tuple.src.u3, &t->src.u3, sizeof(t->src.u3)) &&
	76	!memcmp(&km->tuple.dst.u3, &t->dst.u3, sizeof(t->dst.u3)) &&
	77	km->tuple.dst.protonum == t->dst.protonum &&
	78	km->tuple.dst.u.all == t->dst.u.all;
	79	}
	80
	81	/* look up the source key for a given tuple */
3bb0d1c0	82	static __be16 gre_keymap_lookup(struct net net, struct nf_conntrack_tuple t)
f09943fe	83	{
22fc4c4c	84	struct nf_gre_net *net_gre = gre_pernet(net);
f09943fe PM	85	struct nf_ct_gre_keymap *km;
	86	__be16 key = 0;
	87
202e651c	88	list_for_each_entry_rcu(km, &net_gre->keymap_list, list) {
f09943fe PM	89	if (gre_key_cmpfn(km, t)) {
	90	key = km->tuple.src.u.gre.key;
	91	break;
	92	}
	93	}
f09943fe	94
0d53778e	95	pr_debug("lookup src key 0x%x for ", key);
3c9fba65	96	nf_ct_dump_tuple(t);
f09943fe PM	97
	98	return key;
	99	}
	100
	101	/* add a single keymap entry, associate with specified master ct */
	102	int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir,
	103	struct nf_conntrack_tuple *t)
	104	{
3bb0d1c0	105	struct net *net = nf_ct_net(ct);
22fc4c4c	106	struct nf_gre_net *net_gre = gre_pernet(net);
1afc5679	107	struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
f09943fe PM	108	struct nf_ct_gre_keymap *kmp, km;
f09943fe PM	109
1afc5679	110	kmp = &ct_pptp_info->keymap[dir];
f09943fe PM	111	if (*kmp) {
f09943fe PM	112	/* check whether it's a retransmission */
202e651c FW	113	list_for_each_entry_rcu(km, &net_gre->keymap_list, list) {
202e651c FW	114	if (gre_key_cmpfn(km, t) && km == *kmp)
f09943fe PM	115	return 0;
f09943fe PM	116	}
0d53778e PM	117	pr_debug("trying to override keymap_%s for ct %p\n",
0d53778e PM	118	dir == IP_CT_DIR_REPLY ? "reply" : "orig", ct);
f09943fe PM	119	return -EEXIST;
	120	}
	121
	122	km = kmalloc(sizeof(*km), GFP_ATOMIC);
	123	if (!km)
	124	return -ENOMEM;
	125	memcpy(&km->tuple, t, sizeof(*t));
	126	*kmp = km;
	127
0d53778e	128	pr_debug("adding new entry %p: ", km);
3c9fba65	129	nf_ct_dump_tuple(&km->tuple);
f09943fe	130
202e651c	131	spin_lock_bh(&keymap_lock);
3bb0d1c0	132	list_add_tail(&km->list, &net_gre->keymap_list);
202e651c	133	spin_unlock_bh(&keymap_lock);
f09943fe PM	134
	135	return 0;
	136	}
	137	EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_add);
	138
	139	/* destroy the keymap entries associated with specified master ct */
	140	void nf_ct_gre_keymap_destroy(struct nf_conn *ct)
	141	{
1afc5679	142	struct nf_ct_pptp_master *ct_pptp_info = nfct_help_data(ct);
f09943fe PM	143	enum ip_conntrack_dir dir;
f09943fe PM	144
0d53778e	145	pr_debug("entering for ct %p\n", ct);
f09943fe	146
202e651c	147	spin_lock_bh(&keymap_lock);
f09943fe	148	for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {
1afc5679	149	if (ct_pptp_info->keymap[dir]) {
0d53778e	150	pr_debug("removing %p from list\n",
1afc5679	151	ct_pptp_info->keymap[dir]);
202e651c FW	152	list_del_rcu(&ct_pptp_info->keymap[dir]->list);
202e651c FW	153	kfree_rcu(ct_pptp_info->keymap[dir], rcu);
1afc5679	154	ct_pptp_info->keymap[dir] = NULL;
f09943fe PM	155	}
f09943fe PM	156	}
202e651c	157	spin_unlock_bh(&keymap_lock);
f09943fe PM	158	}
	159	EXPORT_SYMBOL_GPL(nf_ct_gre_keymap_destroy);
	160
	161	/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */
	162
f09943fe	163	/* gre hdr info to tuple */
df5e1629 FW	164	bool gre_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
df5e1629 FW	165	struct net net, struct nf_conntrack_tuple tuple)
f09943fe	166	{
c579a9e7 GF	167	const struct pptp_gre_header *pgrehdr;
c579a9e7 GF	168	struct pptp_gre_header _pgrehdr;
f09943fe	169	__be16 srckey;
c579a9e7 GF	170	const struct gre_base_hdr *grehdr;
c579a9e7 GF	171	struct gre_base_hdr _grehdr;
f09943fe PM	172
	173	/* first only delinearize old RFC1701 GRE header */
	174	grehdr = skb_header_pointer(skb, dataoff, sizeof(_grehdr), &_grehdr);
c579a9e7	175	if (!grehdr \|\| (grehdr->flags & GRE_VERSION) != GRE_VERSION_1) {
f09943fe PM	176	/* try to behave like "nf_conntrack_proto_generic" */
	177	tuple->src.u.all = 0;
	178	tuple->dst.u.all = 0;
09f263cd	179	return true;
f09943fe PM	180	}
	181
	182	/* PPTP header is variable length, only need up to the call_id field */
	183	pgrehdr = skb_header_pointer(skb, dataoff, 8, &_pgrehdr);
	184	if (!pgrehdr)
09f263cd	185	return true;
f09943fe	186
ecc6569f	187	if (grehdr->protocol != GRE_PROTO_PPP) {
c579a9e7	188	pr_debug("Unsupported GRE proto(0x%x)\n", ntohs(grehdr->protocol));
09f263cd	189	return false;
f09943fe PM	190	}
	191
	192	tuple->dst.u.gre.key = pgrehdr->call_id;
3bb0d1c0	193	srckey = gre_keymap_lookup(net, tuple);
f09943fe PM	194	tuple->src.u.gre.key = srckey;
f09943fe PM	195
09f263cd	196	return true;
f09943fe PM	197	}
f09943fe PM	198
ea48cc83	199	#ifdef CONFIG_NF_CONNTRACK_PROCFS
f09943fe	200	/* print private data for conntrack */
37246a58	201	static void gre_print_conntrack(struct seq_file s, struct nf_conn ct)
f09943fe	202	{
37246a58 SRRH	203	seq_printf(s, "timeout=%u, stream_timeout=%u ",
	204	(ct->proto.gre.timeout / HZ),
	205	(ct->proto.gre.stream_timeout / HZ));
f09943fe	206	}
ea48cc83	207	#endif
f09943fe	208
2c8503f5 PNA	209	static unsigned int gre_get_timeouts(struct net net)
2c8503f5 PNA	210	{
22fc4c4c	211	return gre_pernet(net)->timeouts;
2c8503f5 PNA	212	}
2c8503f5 PNA	213
f09943fe	214	/* Returns verdict for packet, and may modify conntrack */
44fb87f6 FW	215	int nf_conntrack_gre_packet(struct nf_conn *ct,
	216	struct sk_buff *skb,
	217	unsigned int dataoff,
	218	enum ip_conntrack_info ctinfo,
	219	const struct nf_hook_state *state)
f09943fe	220	{
dd2934a9 FW	221	if (state->pf != NFPROTO_IPV4)
	222	return -NF_ACCEPT;
	223
9976fc6e FW	224	if (!nf_ct_is_confirmed(ct)) {
	225	unsigned int *timeouts = nf_ct_timeout_lookup(ct);
	226
	227	if (!timeouts)
	228	timeouts = gre_get_timeouts(nf_ct_net(ct));
	229
	230	/* initialize to sane value. Ideally a conntrack helper
	231	* (e.g. in case of pptp) is increasing them */
	232	ct->proto.gre.stream_timeout = timeouts[GRE_CT_REPLIED];
	233	ct->proto.gre.timeout = timeouts[GRE_CT_UNREPLIED];
	234	}
	235
f09943fe PM	236	/* If we've seen traffic both ways, this is a GRE connection.
	237	* Extend timeout. */
	238	if (ct->status & IPS_SEEN_REPLY) {
	239	nf_ct_refresh_acct(ct, ctinfo, skb,
	240	ct->proto.gre.stream_timeout);
	241	/* Also, more likely to be important, and not a probe. */
98d9ae84 FW	242	if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
98d9ae84 FW	243	nf_conntrack_event_cache(IPCT_ASSURED, ct);
f09943fe PM	244	} else
	245	nf_ct_refresh_acct(ct, ctinfo, skb,
	246	ct->proto.gre.timeout);
	247
	248	return NF_ACCEPT;
	249	}
	250
a874752a	251	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
50978462 PNA	252
	253	#include <linux/netfilter/nfnetlink.h>
	254	#include <linux/netfilter/nfnetlink_cttimeout.h>
	255
8264deb8 G	256	static int gre_timeout_nlattr_to_obj(struct nlattr *tb[],
8264deb8 G	257	struct net net, void data)
50978462 PNA	258	{
50978462 PNA	259	unsigned int *timeouts = data;
22fc4c4c	260	struct nf_gre_net *net_gre = gre_pernet(net);
50978462	261
c779e849 FW	262	if (!timeouts)
c779e849 FW	263	timeouts = gre_get_timeouts(net);
50978462	264	/* set default timeouts for GRE. */
22fc4c4c FW	265	timeouts[GRE_CT_UNREPLIED] = net_gre->timeouts[GRE_CT_UNREPLIED];
22fc4c4c FW	266	timeouts[GRE_CT_REPLIED] = net_gre->timeouts[GRE_CT_REPLIED];
50978462 PNA	267
	268	if (tb[CTA_TIMEOUT_GRE_UNREPLIED]) {
	269	timeouts[GRE_CT_UNREPLIED] =
	270	ntohl(nla_get_be32(tb[CTA_TIMEOUT_GRE_UNREPLIED])) * HZ;
	271	}
	272	if (tb[CTA_TIMEOUT_GRE_REPLIED]) {
	273	timeouts[GRE_CT_REPLIED] =
	274	ntohl(nla_get_be32(tb[CTA_TIMEOUT_GRE_REPLIED])) * HZ;
	275	}
	276	return 0;
	277	}
	278
	279	static int
	280	gre_timeout_obj_to_nlattr(struct sk_buff skb, const void data)
	281	{
	282	const unsigned int *timeouts = data;
	283
242ddfc0 DM	284	if (nla_put_be32(skb, CTA_TIMEOUT_GRE_UNREPLIED,
	285	htonl(timeouts[GRE_CT_UNREPLIED] / HZ)) \|\|
	286	nla_put_be32(skb, CTA_TIMEOUT_GRE_REPLIED,
	287	htonl(timeouts[GRE_CT_REPLIED] / HZ)))
	288	goto nla_put_failure;
50978462 PNA	289	return 0;
	290
	291	nla_put_failure:
	292	return -ENOSPC;
	293	}
	294
	295	static const struct nla_policy
	296	gre_timeout_nla_policy[CTA_TIMEOUT_GRE_MAX+1] = {
	297	[CTA_TIMEOUT_GRE_UNREPLIED] = { .type = NLA_U32 },
	298	[CTA_TIMEOUT_GRE_REPLIED] = { .type = NLA_U32 },
	299	};
a874752a	300	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
50978462	301
2a389de8	302	void nf_conntrack_gre_init_net(struct net *net)
4f71d80f	303	{
22fc4c4c	304	struct nf_gre_net *net_gre = gre_pernet(net);
4f71d80f G	305	int i;
4f71d80f G	306
4f71d80f G	307	INIT_LIST_HEAD(&net_gre->keymap_list);
4f71d80f G	308	for (i = 0; i < GRE_CT_MAX; i++)
22fc4c4c	309	net_gre->timeouts[i] = gre_timeouts[i];
4f71d80f G	310	}
4f71d80f G	311
f09943fe	312	/* protocol helper struct */
22fc4c4c	313	const struct nf_conntrack_l4proto nf_conntrack_l4proto_gre = {
f09943fe	314	.l4proto = IPPROTO_GRE,
ea48cc83	315	#ifdef CONFIG_NF_CONNTRACK_PROCFS
f09943fe	316	.print_conntrack = gre_print_conntrack,
ea48cc83	317	#endif
c0cd1156	318	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
fdf70832	319	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e	320	.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
fdf70832	321	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	322	.nla_policy = nf_ct_port_nla_policy,
f09943fe	323	#endif
a874752a	324	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
50978462 PNA	325	.ctnl_timeout = {
	326	.nlattr_to_obj = gre_timeout_nlattr_to_obj,
	327	.obj_to_nlattr = gre_timeout_obj_to_nlattr,
	328	.nlattr_max = CTA_TIMEOUT_GRE_MAX,
	329	.obj_size = sizeof(unsigned int) * GRE_CT_MAX,
	330	.nla_policy = gre_timeout_nla_policy,
	331	},
a874752a	332	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
f09943fe	333	};