[net-next-2.6.git] / net / ipv4 / netfilter / nf_conntrack_l3proto_ipv4.c


/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.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/ip.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/icmp.h>
#include <linux/sysctl.h>
#include <net/route.h>
#include <net/ip.h>

#include <linux/netfilter_ipv4.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
#include <net/netfilter/nf_nat_helper.h>
#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
#include <net/netfilter/nf_log.h>

int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
			      struct nf_conn *ct,
			      enum ip_conntrack_info ctinfo);
EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);

static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
			      struct nf_conntrack_tuple *tuple)
{
	const __be32 *ap;
	__be32 _addrs[2];
	ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
				sizeof(u_int32_t) * 2, _addrs);
	if (ap == NULL)
		return false;

	tuple->src.u3.ip = ap[0];
	tuple->dst.u3.ip = ap[1];

	return true;
}

static bool ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
			      const struct nf_conntrack_tuple *orig)
{
	tuple->src.u3.ip = orig->dst.u3.ip;
	tuple->dst.u3.ip = orig->src.u3.ip;

	return true;
}

static int ipv4_print_tuple(struct seq_file *s,
			    const struct nf_conntrack_tuple *tuple)
{
	return seq_printf(s, "src=%pI4 dst=%pI4 ",
			  &tuple->src.u3.ip, &tuple->dst.u3.ip);
}

static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
			    unsigned int *dataoff, u_int8_t *protonum)
{
	const struct iphdr *iph;
	struct iphdr _iph;

	iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
	if (iph == NULL)
		return -NF_DROP;

	/* Conntrack defragments packets, we might still see fragments
	 * inside ICMP packets though. */
	if (iph->frag_off & htons(IP_OFFSET))
		return -NF_DROP;

	*dataoff = nhoff + (iph->ihl << 2);
	*protonum = iph->protocol;

	return NF_ACCEPT;
}

static unsigned int ipv4_confirm(unsigned int hooknum,
				 struct sk_buff *skb,
				 const struct net_device *in,
				 const struct net_device *out,
				 int (*okfn)(struct sk_buff *))
{
	struct nf_conn *ct;
	enum ip_conntrack_info ctinfo;
	const struct nf_conn_help *help;
	const struct nf_conntrack_helper *helper;
	unsigned int ret;

	/* This is where we call the helper: as the packet goes out. */
	ct = nf_ct_get(skb, &ctinfo);
	if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
		goto out;

	help = nfct_help(ct);
	if (!help)
		goto out;

	/* rcu_read_lock()ed by nf_hook_slow */
	helper = rcu_dereference(help->helper);
	if (!helper)
		goto out;

	ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
			   ct, ctinfo);
	if (ret != NF_ACCEPT) {
		nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
			      "nf_ct_%s: dropping packet", helper->name);
		return ret;
	}

	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
		typeof(nf_nat_seq_adjust_hook) seq_adjust;

		seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
		if (!seq_adjust || !seq_adjust(skb, ct, ctinfo)) {
			NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
			return NF_DROP;
		}
	}
out:
	/* We've seen it coming out the other side: confirm it */
	return nf_conntrack_confirm(skb);
}

static unsigned int ipv4_conntrack_in(unsigned int hooknum,
				      struct sk_buff *skb,
				      const struct net_device *in,
				      const struct net_device *out,
				      int (*okfn)(struct sk_buff *))
{
	return nf_conntrack_in(dev_net(in), PF_INET, hooknum, skb);
}

static unsigned int ipv4_conntrack_local(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	/* root is playing with raw sockets. */
	if (skb->len < sizeof(struct iphdr) ||
	    ip_hdrlen(skb) < sizeof(struct iphdr))
		return NF_ACCEPT;
	return nf_conntrack_in(dev_net(out), PF_INET, hooknum, skb);
}

/* Connection tracking may drop packets, but never alters them, so
   make it the first hook. */
static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
	{
		.hook		= ipv4_conntrack_in,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV4,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP_PRI_CONNTRACK,
	},
	{
		.hook		= ipv4_conntrack_local,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV4,
		.hooknum	= NF_INET_LOCAL_OUT,
		.priority	= NF_IP_PRI_CONNTRACK,
	},
	{
		.hook		= ipv4_confirm,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV4,
		.hooknum	= NF_INET_POST_ROUTING,
		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
	},
	{
		.hook		= ipv4_confirm,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV4,
		.hooknum	= NF_INET_LOCAL_IN,
		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
	},
};

#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
static int log_invalid_proto_min = 0;
static int log_invalid_proto_max = 255;

static ctl_table ip_ct_sysctl_table[] = {
	{
		.procname	= "ip_conntrack_max",
		.data		= &nf_conntrack_max,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "ip_conntrack_count",
		.data		= &init_net.ct.count,
		.maxlen		= sizeof(int),
		.mode		= 0444,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "ip_conntrack_buckets",
		.data		= &init_net.ct.htable_size,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0444,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "ip_conntrack_checksum",
		.data		= &init_net.ct.sysctl_checksum,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec,
	},
	{
		.procname	= "ip_conntrack_log_invalid",
		.data		= &init_net.ct.sysctl_log_invalid,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_minmax,
		.extra1		= &log_invalid_proto_min,
		.extra2		= &log_invalid_proto_max,
	},
	{ }
};
#endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */

/* Fast function for those who don't want to parse /proc (and I don't
   blame them). */
/* Reversing the socket's dst/src point of view gives us the reply
   mapping. */
static int
getorigdst(struct sock *sk, int optval, void __user *user, int *len)
{
	const struct inet_sock *inet = inet_sk(sk);
	const struct nf_conntrack_tuple_hash *h;
	struct nf_conntrack_tuple tuple;

	memset(&tuple, 0, sizeof(tuple));
	tuple.src.u3.ip = inet->inet_rcv_saddr;
	tuple.src.u.tcp.port = inet->inet_sport;
	tuple.dst.u3.ip = inet->inet_daddr;
	tuple.dst.u.tcp.port = inet->inet_dport;
	tuple.src.l3num = PF_INET;
	tuple.dst.protonum = sk->sk_protocol;

	/* We only do TCP and SCTP at the moment: is there a better way? */
	if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP) {
		pr_debug("SO_ORIGINAL_DST: Not a TCP/SCTP socket\n");
		return -ENOPROTOOPT;
	}

	if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
		pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
			 *len, sizeof(struct sockaddr_in));
		return -EINVAL;
	}

	h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
	if (h) {
		struct sockaddr_in sin;
		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);

		sin.sin_family = AF_INET;
		sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
			.tuple.dst.u.tcp.port;
		sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
			.tuple.dst.u3.ip;
		memset(sin.sin_zero, 0, sizeof(sin.sin_zero));

		pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
			 &sin.sin_addr.s_addr, ntohs(sin.sin_port));
		nf_ct_put(ct);
		if (copy_to_user(user, &sin, sizeof(sin)) != 0)
			return -EFAULT;
		else
			return 0;
	}
	pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
		 &tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
		 &tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
	return -ENOENT;
}

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

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

static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
				const struct nf_conntrack_tuple *tuple)
{
	NLA_PUT_BE32(skb, CTA_IP_V4_SRC, tuple->src.u3.ip);
	NLA_PUT_BE32(skb, CTA_IP_V4_DST, tuple->dst.u3.ip);
	return 0;

nla_put_failure:
	return -1;
}

static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
	[CTA_IP_V4_SRC]	= { .type = NLA_U32 },
	[CTA_IP_V4_DST]	= { .type = NLA_U32 },
};

static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
				struct nf_conntrack_tuple *t)
{
	if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
		return -EINVAL;

	t->src.u3.ip = nla_get_be32(tb[CTA_IP_V4_SRC]);
	t->dst.u3.ip = nla_get_be32(tb[CTA_IP_V4_DST]);

	return 0;
}

static int ipv4_nlattr_tuple_size(void)
{
	return nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1);
}
#endif

static struct nf_sockopt_ops so_getorigdst = {
	.pf		= PF_INET,
	.get_optmin	= SO_ORIGINAL_DST,
	.get_optmax	= SO_ORIGINAL_DST+1,
	.get		= &getorigdst,
	.owner		= THIS_MODULE,
};

struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
	.l3proto	 = PF_INET,
	.name		 = "ipv4",
	.pkt_to_tuple	 = ipv4_pkt_to_tuple,
	.invert_tuple	 = ipv4_invert_tuple,
	.print_tuple	 = ipv4_print_tuple,
	.get_l4proto	 = ipv4_get_l4proto,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr = ipv4_tuple_to_nlattr,
	.nlattr_tuple_size = ipv4_nlattr_tuple_size,
	.nlattr_to_tuple = ipv4_nlattr_to_tuple,
	.nla_policy	 = ipv4_nla_policy,
#endif
#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	.ctl_table_path  = nf_net_ipv4_netfilter_sysctl_path,
	.ctl_table	 = ip_ct_sysctl_table,
#endif
	.me		 = THIS_MODULE,
};

module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
		  &nf_conntrack_htable_size, 0600);

MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
MODULE_ALIAS("ip_conntrack");
MODULE_LICENSE("GPL");

static int __init nf_conntrack_l3proto_ipv4_init(void)
{
	int ret = 0;

	need_conntrack();
	nf_defrag_ipv4_enable();

	ret = nf_register_sockopt(&so_getorigdst);
	if (ret < 0) {
		printk(KERN_ERR "Unable to register netfilter socket option\n");
		return ret;
	}

	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
	if (ret < 0) {
		printk("nf_conntrack_ipv4: can't register tcp.\n");
		goto cleanup_sockopt;
	}

	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
	if (ret < 0) {
		printk("nf_conntrack_ipv4: can't register udp.\n");
		goto cleanup_tcp;
	}

	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
	if (ret < 0) {
		printk("nf_conntrack_ipv4: can't register icmp.\n");
		goto cleanup_udp;
	}

	ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
	if (ret < 0) {
		printk("nf_conntrack_ipv4: can't register ipv4\n");
		goto cleanup_icmp;
	}

	ret = nf_register_hooks(ipv4_conntrack_ops,
				ARRAY_SIZE(ipv4_conntrack_ops));
	if (ret < 0) {
		printk("nf_conntrack_ipv4: can't register hooks.\n");
		goto cleanup_ipv4;
	}
#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	ret = nf_conntrack_ipv4_compat_init();
	if (ret < 0)
		goto cleanup_hooks;
#endif
	return ret;
#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
 cleanup_hooks:
	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
#endif
 cleanup_ipv4:
	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
 cleanup_icmp:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
 cleanup_udp:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
 cleanup_tcp:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
 cleanup_sockopt:
	nf_unregister_sockopt(&so_getorigdst);
	return ret;
}

static void __exit nf_conntrack_l3proto_ipv4_fini(void)
{
	synchronize_net();
#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	nf_conntrack_ipv4_compat_fini();
#endif
	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
	nf_unregister_sockopt(&so_getorigdst);
}

module_init(nf_conntrack_l3proto_ipv4_init);
module_exit(nf_conntrack_l3proto_ipv4_fini);

void need_ipv4_conntrack(void)
{
	return;
}
EXPORT_SYMBOL_GPL(need_ipv4_conntrack);
Commit	Line	Data
73e4022f	1
9fb9cbb1 YK	2	/* (C) 1999-2001 Paul `Rusty' Russell
	3	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
9fb9cbb1 YK	8	*/
9fb9cbb1 YK	9
9fb9cbb1 YK	10	#include <linux/types.h>
	11	#include <linux/ip.h>
	12	#include <linux/netfilter.h>
	13	#include <linux/module.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/icmp.h>
	16	#include <linux/sysctl.h>
0ae2cfe7	17	#include <net/route.h>
9fb9cbb1 YK	18	#include <net/ip.h>
	19
	20	#include <linux/netfilter_ipv4.h>
	21	#include <net/netfilter/nf_conntrack.h>
	22	#include <net/netfilter/nf_conntrack_helper.h>
605dcad6	23	#include <net/netfilter/nf_conntrack_l4proto.h>
9fb9cbb1	24	#include <net/netfilter/nf_conntrack_l3proto.h>
5d0aa2cc	25	#include <net/netfilter/nf_conntrack_zones.h>
9fb9cbb1 YK	26	#include <net/netfilter/nf_conntrack_core.h>
9fb9cbb1 YK	27	#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
dd13b010	28	#include <net/netfilter/nf_nat_helper.h>
73e4022f	29	#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
74f7a655	30	#include <net/netfilter/nf_log.h>
dd13b010 PM	31
	32	int (nf_nat_seq_adjust_hook)(struct sk_buff skb,
	33	struct nf_conn *ct,
	34	enum ip_conntrack_info ctinfo);
	35	EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
9fb9cbb1	36
8ce8439a JE	37	static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
8ce8439a JE	38	struct nf_conntrack_tuple *tuple)
9fb9cbb1	39	{
32948588 JE	40	const __be32 *ap;
32948588 JE	41	__be32 _addrs[2];
9fb9cbb1 YK	42	ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
	43	sizeof(u_int32_t) * 2, _addrs);
	44	if (ap == NULL)
8ce8439a	45	return false;
9fb9cbb1 YK	46
	47	tuple->src.u3.ip = ap[0];
	48	tuple->dst.u3.ip = ap[1];
	49
8ce8439a	50	return true;
9fb9cbb1 YK	51	}
9fb9cbb1 YK	52
8ce8439a JE	53	static bool ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
8ce8439a JE	54	const struct nf_conntrack_tuple *orig)
9fb9cbb1 YK	55	{
	56	tuple->src.u3.ip = orig->dst.u3.ip;
	57	tuple->dst.u3.ip = orig->src.u3.ip;
	58
8ce8439a	59	return true;
9fb9cbb1 YK	60	}
	61
	62	static int ipv4_print_tuple(struct seq_file *s,
	63	const struct nf_conntrack_tuple *tuple)
	64	{
cffee385 HH	65	return seq_printf(s, "src=%pI4 dst=%pI4 ",
cffee385 HH	66	&tuple->src.u3.ip, &tuple->dst.u3.ip);
9fb9cbb1 YK	67	}
9fb9cbb1 YK	68
ffc30690 YK	69	static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
ffc30690 YK	70	unsigned int dataoff, u_int8_t protonum)
9fb9cbb1	71	{
32948588 JE	72	const struct iphdr *iph;
32948588 JE	73	struct iphdr _iph;
ffc30690 YK	74
	75	iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
	76	if (iph == NULL)
	77	return -NF_DROP;
	78
0fb96701 PM	79	/* Conntrack defragments packets, we might still see fragments
	80	* inside ICMP packets though. */
	81	if (iph->frag_off & htons(IP_OFFSET))
9fb9cbb1	82	return -NF_DROP;
9fb9cbb1	83
ffc30690 YK	84	*dataoff = nhoff + (iph->ihl << 2);
ffc30690 YK	85	*protonum = iph->protocol;
9fb9cbb1 YK	86
	87	return NF_ACCEPT;
	88	}
	89
9fb9cbb1	90	static unsigned int ipv4_confirm(unsigned int hooknum,
3db05fea	91	struct sk_buff *skb,
9fb9cbb1 YK	92	const struct net_device *in,
	93	const struct net_device *out,
	94	int (okfn)(struct sk_buff ))
9fb9cbb1 YK	95	{
	96	struct nf_conn *ct;
	97	enum ip_conntrack_info ctinfo;
32948588 JE	98	const struct nf_conn_help *help;
32948588 JE	99	const struct nf_conntrack_helper *helper;
dd13b010	100	unsigned int ret;
9fb9cbb1 YK	101
9fb9cbb1 YK	102	/* This is where we call the helper: as the packet goes out. */
3db05fea	103	ct = nf_ct_get(skb, &ctinfo);
6442f1cf	104	if (!ct \|\| ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
dd13b010	105	goto out;
dc808fe2 HW	106
dc808fe2 HW	107	help = nfct_help(ct);
3c158f7f	108	if (!help)
dd13b010 PM	109	goto out;
dd13b010 PM	110
3c158f7f PM	111	/* rcu_read_lock()ed by nf_hook_slow */
	112	helper = rcu_dereference(help->helper);
	113	if (!helper)
dd13b010 PM	114	goto out;
	115
	116	ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
	117	ct, ctinfo);
74f7a655 PM	118	if (ret != NF_ACCEPT) {
	119	nf_log_packet(NFPROTO_IPV4, hooknum, skb, in, out, NULL,
	120	"nf_ct_%s: dropping packet", helper->name);
dd13b010	121	return ret;
74f7a655	122	}
dd13b010 PM	123
	124	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
	125	typeof(nf_nat_seq_adjust_hook) seq_adjust;
	126
	127	seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
1db7a748 PNA	128	if (!seq_adjust \|\| !seq_adjust(skb, ct, ctinfo)) {
1db7a748 PNA	129	NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop);
dd13b010	130	return NF_DROP;
1db7a748	131	}
dd13b010 PM	132	}
	133	out:
	134	/* We've seen it coming out the other side: confirm it */
	135	return nf_conntrack_confirm(skb);
9fb9cbb1 YK	136	}
9fb9cbb1 YK	137
9fb9cbb1	138	static unsigned int ipv4_conntrack_in(unsigned int hooknum,
3db05fea	139	struct sk_buff *skb,
9fb9cbb1 YK	140	const struct net_device *in,
	141	const struct net_device *out,
	142	int (okfn)(struct sk_buff ))
	143	{
a702a65f	144	return nf_conntrack_in(dev_net(in), PF_INET, hooknum, skb);
9fb9cbb1 YK	145	}
	146
	147	static unsigned int ipv4_conntrack_local(unsigned int hooknum,
3db05fea	148	struct sk_buff *skb,
e905a9ed YH	149	const struct net_device *in,
	150	const struct net_device *out,
	151	int (okfn)(struct sk_buff ))
9fb9cbb1 YK	152	{
9fb9cbb1 YK	153	/* root is playing with raw sockets. */
3db05fea	154	if (skb->len < sizeof(struct iphdr) \|\|
88843104	155	ip_hdrlen(skb) < sizeof(struct iphdr))
9fb9cbb1	156	return NF_ACCEPT;
a702a65f	157	return nf_conntrack_in(dev_net(out), PF_INET, hooknum, skb);
9fb9cbb1 YK	158	}
	159
	160	/* Connection tracking may drop packets, but never alters them, so
	161	make it the first hook. */
1999414a	162	static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
964ddaa1 PM	163	{
	164	.hook = ipv4_conntrack_in,
	165	.owner = THIS_MODULE,
57750a22	166	.pf = NFPROTO_IPV4,
6e23ae2a	167	.hooknum = NF_INET_PRE_ROUTING,
964ddaa1 PM	168	.priority = NF_IP_PRI_CONNTRACK,
964ddaa1 PM	169	},
964ddaa1 PM	170	{
	171	.hook = ipv4_conntrack_local,
	172	.owner = THIS_MODULE,
57750a22	173	.pf = NFPROTO_IPV4,
6e23ae2a	174	.hooknum = NF_INET_LOCAL_OUT,
964ddaa1 PM	175	.priority = NF_IP_PRI_CONNTRACK,
964ddaa1 PM	176	},
964ddaa1 PM	177	{
	178	.hook = ipv4_confirm,
	179	.owner = THIS_MODULE,
57750a22	180	.pf = NFPROTO_IPV4,
6e23ae2a	181	.hooknum = NF_INET_POST_ROUTING,
964ddaa1 PM	182	.priority = NF_IP_PRI_CONNTRACK_CONFIRM,
	183	},
	184	{
	185	.hook = ipv4_confirm,
	186	.owner = THIS_MODULE,
57750a22	187	.pf = NFPROTO_IPV4,
6e23ae2a	188	.hooknum = NF_INET_LOCAL_IN,
964ddaa1 PM	189	.priority = NF_IP_PRI_CONNTRACK_CONFIRM,
964ddaa1 PM	190	},
9fb9cbb1 YK	191	};
9fb9cbb1 YK	192
a999e683 PM	193	#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	194	static int log_invalid_proto_min = 0;
	195	static int log_invalid_proto_max = 255;
	196
	197	static ctl_table ip_ct_sysctl_table[] = {
	198	{
a999e683 PM	199	.procname = "ip_conntrack_max",
	200	.data = &nf_conntrack_max,
	201	.maxlen = sizeof(int),
	202	.mode = 0644,
6d9f239a	203	.proc_handler = proc_dointvec,
a999e683 PM	204	},
a999e683 PM	205	{
a999e683	206	.procname = "ip_conntrack_count",
49ac8713	207	.data = &init_net.ct.count,
a999e683 PM	208	.maxlen = sizeof(int),
a999e683 PM	209	.mode = 0444,
6d9f239a	210	.proc_handler = proc_dointvec,
a999e683 PM	211	},
a999e683 PM	212	{
a999e683	213	.procname = "ip_conntrack_buckets",
d696c7bd	214	.data = &init_net.ct.htable_size,
a999e683 PM	215	.maxlen = sizeof(unsigned int),
a999e683 PM	216	.mode = 0444,
6d9f239a	217	.proc_handler = proc_dointvec,
a999e683 PM	218	},
a999e683 PM	219	{
a999e683	220	.procname = "ip_conntrack_checksum",
c04d0552	221	.data = &init_net.ct.sysctl_checksum,
a999e683 PM	222	.maxlen = sizeof(int),
a999e683 PM	223	.mode = 0644,
6d9f239a	224	.proc_handler = proc_dointvec,
a999e683 PM	225	},
a999e683 PM	226	{
a999e683	227	.procname = "ip_conntrack_log_invalid",
c2a2c7e0	228	.data = &init_net.ct.sysctl_log_invalid,
a999e683 PM	229	.maxlen = sizeof(unsigned int),
a999e683 PM	230	.mode = 0644,
6d9f239a	231	.proc_handler = proc_dointvec_minmax,
a999e683 PM	232	.extra1 = &log_invalid_proto_min,
	233	.extra2 = &log_invalid_proto_max,
	234	},
f8572d8f	235	{ }
a999e683 PM	236	};
	237	#endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
	238
9fb9cbb1 YK	239	/* Fast function for those who don't want to parse /proc (and I don't
	240	blame them). */
	241	/* Reversing the socket's dst/src point of view gives us the reply
	242	mapping. */
	243	static int
	244	getorigdst(struct sock sk, int optval, void __user user, int *len)
	245	{
32948588 JE	246	const struct inet_sock *inet = inet_sk(sk);
32948588 JE	247	const struct nf_conntrack_tuple_hash *h;
9fb9cbb1	248	struct nf_conntrack_tuple tuple;
e905a9ed	249
443a70d5	250	memset(&tuple, 0, sizeof(tuple));
c720c7e8 ED	251	tuple.src.u3.ip = inet->inet_rcv_saddr;
	252	tuple.src.u.tcp.port = inet->inet_sport;
	253	tuple.dst.u3.ip = inet->inet_daddr;
	254	tuple.dst.u.tcp.port = inet->inet_dport;
9fb9cbb1	255	tuple.src.l3num = PF_INET;
54981279	256	tuple.dst.protonum = sk->sk_protocol;
9fb9cbb1	257
54981279 RL	258	/* We only do TCP and SCTP at the moment: is there a better way? */
	259	if (sk->sk_protocol != IPPROTO_TCP && sk->sk_protocol != IPPROTO_SCTP) {
	260	pr_debug("SO_ORIGINAL_DST: Not a TCP/SCTP socket\n");
9fb9cbb1 YK	261	return -ENOPROTOOPT;
	262	}
	263
	264	if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
0d53778e PM	265	pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
0d53778e PM	266	*len, sizeof(struct sockaddr_in));
9fb9cbb1 YK	267	return -EINVAL;
	268	}
	269
5d0aa2cc	270	h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
9fb9cbb1 YK	271	if (h) {
	272	struct sockaddr_in sin;
	273	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
	274
	275	sin.sin_family = AF_INET;
	276	sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
	277	.tuple.dst.u.tcp.port;
	278	sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
	279	.tuple.dst.u3.ip;
6c813c3f	280	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
9fb9cbb1	281
cffee385 HH	282	pr_debug("SO_ORIGINAL_DST: %pI4 %u\n",
cffee385 HH	283	&sin.sin_addr.s_addr, ntohs(sin.sin_port));
9fb9cbb1 YK	284	nf_ct_put(ct);
	285	if (copy_to_user(user, &sin, sizeof(sin)) != 0)
	286	return -EFAULT;
	287	else
	288	return 0;
	289	}
cffee385 HH	290	pr_debug("SO_ORIGINAL_DST: Can't find %pI4/%u-%pI4/%u.\n",
	291	&tuple.src.u3.ip, ntohs(tuple.src.u.tcp.port),
	292	&tuple.dst.u3.ip, ntohs(tuple.dst.u.tcp.port));
9fb9cbb1 YK	293	return -ENOENT;
	294	}
	295
e281db5c	296	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
c1d10adb PNA	297
	298	#include <linux/netfilter/nfnetlink.h>
	299	#include <linux/netfilter/nfnetlink_conntrack.h>
	300
fdf70832	301	static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
c1d10adb PNA	302	const struct nf_conntrack_tuple *tuple)
c1d10adb PNA	303	{
77236b6e PM	304	NLA_PUT_BE32(skb, CTA_IP_V4_SRC, tuple->src.u3.ip);
77236b6e PM	305	NLA_PUT_BE32(skb, CTA_IP_V4_DST, tuple->dst.u3.ip);
c1d10adb PNA	306	return 0;
c1d10adb PNA	307
df6fb868	308	nla_put_failure:
c1d10adb PNA	309	return -1;
	310	}
	311
f73e924c PM	312	static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
	313	[CTA_IP_V4_SRC] = { .type = NLA_U32 },
	314	[CTA_IP_V4_DST] = { .type = NLA_U32 },
c1d10adb PNA	315	};
c1d10adb PNA	316
fdf70832	317	static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
c1d10adb PNA	318	struct nf_conntrack_tuple *t)
c1d10adb PNA	319	{
df6fb868	320	if (!tb[CTA_IP_V4_SRC] \|\| !tb[CTA_IP_V4_DST])
c1d10adb PNA	321	return -EINVAL;
c1d10adb PNA	322
77236b6e PM	323	t->src.u3.ip = nla_get_be32(tb[CTA_IP_V4_SRC]);
77236b6e PM	324	t->dst.u3.ip = nla_get_be32(tb[CTA_IP_V4_DST]);
c1d10adb PNA	325
	326	return 0;
	327	}
a400c30e HE	328
	329	static int ipv4_nlattr_tuple_size(void)
	330	{
	331	return nla_policy_len(ipv4_nla_policy, CTA_IP_MAX + 1);
	332	}
c1d10adb PNA	333	#endif
c1d10adb PNA	334
9fb9cbb1 YK	335	static struct nf_sockopt_ops so_getorigdst = {
	336	.pf = PF_INET,
	337	.get_optmin = SO_ORIGINAL_DST,
	338	.get_optmax = SO_ORIGINAL_DST+1,
	339	.get = &getorigdst,
16fcec35	340	.owner = THIS_MODULE,
9fb9cbb1 YK	341	};
9fb9cbb1 YK	342
61075af5	343	struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
9fb9cbb1 YK	344	.l3proto = PF_INET,
	345	.name = "ipv4",
	346	.pkt_to_tuple = ipv4_pkt_to_tuple,
	347	.invert_tuple = ipv4_invert_tuple,
	348	.print_tuple = ipv4_print_tuple,
ffc30690	349	.get_l4proto = ipv4_get_l4proto,
e281db5c	350	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832	351	.tuple_to_nlattr = ipv4_tuple_to_nlattr,
a400c30e	352	.nlattr_tuple_size = ipv4_nlattr_tuple_size,
fdf70832	353	.nlattr_to_tuple = ipv4_nlattr_to_tuple,
f73e924c	354	.nla_policy = ipv4_nla_policy,
a999e683 PM	355	#endif
	356	#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	357	.ctl_table_path = nf_net_ipv4_netfilter_sysctl_path,
	358	.ctl_table = ip_ct_sysctl_table,
c1d10adb	359	#endif
9fb9cbb1 YK	360	.me = THIS_MODULE,
	361	};
	362
fae718dd PM	363	module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
	364	&nf_conntrack_htable_size, 0600);
	365
32292a7f	366	MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
d2483dde	367	MODULE_ALIAS("ip_conntrack");
32292a7f PM	368	MODULE_LICENSE("GPL");
	369
	370	static int __init nf_conntrack_l3proto_ipv4_init(void)
9fb9cbb1 YK	371	{
	372	int ret = 0;
	373
32292a7f	374	need_conntrack();
73e4022f	375	nf_defrag_ipv4_enable();
9fb9cbb1 YK	376
	377	ret = nf_register_sockopt(&so_getorigdst);
	378	if (ret < 0) {
	379	printk(KERN_ERR "Unable to register netfilter socket option\n");
32292a7f	380	return ret;
9fb9cbb1 YK	381	}
9fb9cbb1 YK	382
605dcad6	383	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
9fb9cbb1 YK	384	if (ret < 0) {
	385	printk("nf_conntrack_ipv4: can't register tcp.\n");
	386	goto cleanup_sockopt;
	387	}
	388
605dcad6	389	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
9fb9cbb1 YK	390	if (ret < 0) {
	391	printk("nf_conntrack_ipv4: can't register udp.\n");
	392	goto cleanup_tcp;
	393	}
	394
605dcad6	395	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
9fb9cbb1 YK	396	if (ret < 0) {
	397	printk("nf_conntrack_ipv4: can't register icmp.\n");
	398	goto cleanup_udp;
	399	}
	400
	401	ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
	402	if (ret < 0) {
	403	printk("nf_conntrack_ipv4: can't register ipv4\n");
	404	goto cleanup_icmp;
	405	}
	406
964ddaa1 PM	407	ret = nf_register_hooks(ipv4_conntrack_ops,
964ddaa1 PM	408	ARRAY_SIZE(ipv4_conntrack_ops));
9fb9cbb1	409	if (ret < 0) {
964ddaa1	410	printk("nf_conntrack_ipv4: can't register hooks.\n");
9fb9cbb1 YK	411	goto cleanup_ipv4;
9fb9cbb1 YK	412	}
e4bd8bce PM	413	#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	414	ret = nf_conntrack_ipv4_compat_init();
	415	if (ret < 0)
	416	goto cleanup_hooks;
	417	#endif
9fb9cbb1	418	return ret;
e4bd8bce PM	419	#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
e4bd8bce PM	420	cleanup_hooks:
e905a9ed	421	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
e4bd8bce	422	#endif
9fb9cbb1 YK	423	cleanup_ipv4:
	424	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
	425	cleanup_icmp:
605dcad6	426	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
9fb9cbb1	427	cleanup_udp:
605dcad6	428	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
9fb9cbb1	429	cleanup_tcp:
605dcad6	430	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
9fb9cbb1 YK	431	cleanup_sockopt:
9fb9cbb1 YK	432	nf_unregister_sockopt(&so_getorigdst);
9fb9cbb1 YK	433	return ret;
	434	}
	435
65b4b4e8	436	static void __exit nf_conntrack_l3proto_ipv4_fini(void)
9fb9cbb1	437	{
32292a7f	438	synchronize_net();
e4bd8bce PM	439	#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
	440	nf_conntrack_ipv4_compat_fini();
	441	#endif
32292a7f PM	442	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
32292a7f PM	443	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
605dcad6 MJ	444	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
	445	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
	446	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
32292a7f	447	nf_unregister_sockopt(&so_getorigdst);
9fb9cbb1 YK	448	}
9fb9cbb1 YK	449
65b4b4e8 AM	450	module_init(nf_conntrack_l3proto_ipv4_init);
65b4b4e8 AM	451	module_exit(nf_conntrack_l3proto_ipv4_fini);
591e6206 PM	452
	453	void need_ipv4_conntrack(void)
	454	{
	455	return;
	456	}
	457	EXPORT_SYMBOL_GPL(need_ipv4_conntrack);