[deliverable/linux.git] / net / netfilter / nf_conntrack_proto_udp.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.
 *
 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 *	- enable working with Layer 3 protocol independent connection tracking.
 *
 * Derived from net/ipv4/netfilter/ip_conntrack_proto_udp.c
 */

#include <linux/types.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/udp.h>
#include <linux/seq_file.h>
#include <linux/skbuff.h>
#include <linux/ipv6.h>
#include <net/ip6_checksum.h>
#include <net/checksum.h>

#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_ecache.h>

static unsigned int nf_ct_udp_timeout __read_mostly = 30*HZ;
static unsigned int nf_ct_udp_timeout_stream __read_mostly = 180*HZ;

static int udp_pkt_to_tuple(const struct sk_buff *skb,
			     unsigned int dataoff,
			     struct nf_conntrack_tuple *tuple)
{
	struct udphdr _hdr, *hp;

	/* Actually only need first 8 bytes. */
	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	if (hp == NULL)
		return 0;

	tuple->src.u.udp.port = hp->source;
	tuple->dst.u.udp.port = hp->dest;

	return 1;
}

static int udp_invert_tuple(struct nf_conntrack_tuple *tuple,
			    const struct nf_conntrack_tuple *orig)
{
	tuple->src.u.udp.port = orig->dst.u.udp.port;
	tuple->dst.u.udp.port = orig->src.u.udp.port;
	return 1;
}

/* Print out the per-protocol part of the tuple. */
static int udp_print_tuple(struct seq_file *s,
			   const struct nf_conntrack_tuple *tuple)
{
	return seq_printf(s, "sport=%hu dport=%hu ",
			  ntohs(tuple->src.u.udp.port),
			  ntohs(tuple->dst.u.udp.port));
}

/* Print out the private part of the conntrack. */
static int udp_print_conntrack(struct seq_file *s,
			       const struct nf_conn *conntrack)
{
	return 0;
}

/* Returns verdict for packet, and may modify conntracktype */
static int udp_packet(struct nf_conn *conntrack,
		      const struct sk_buff *skb,
		      unsigned int dataoff,
		      enum ip_conntrack_info ctinfo,
		      int pf,
		      unsigned int hooknum)
{
	/* If we've seen traffic both ways, this is some kind of UDP
	   stream.  Extend timeout. */
	if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
		nf_ct_refresh_acct(conntrack, ctinfo, skb,
				   nf_ct_udp_timeout_stream);
		/* Also, more likely to be important, and not a probe */
		if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))
			nf_conntrack_event_cache(IPCT_STATUS, skb);
	} else
		nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout);

	return NF_ACCEPT;
}

/* Called when a new connection for this protocol found. */
static int udp_new(struct nf_conn *conntrack, const struct sk_buff *skb,
		   unsigned int dataoff)
{
	return 1;
}

static int udp_error(struct sk_buff *skb, unsigned int dataoff,
		     enum ip_conntrack_info *ctinfo,
		     int pf,
		     unsigned int hooknum)
{
	unsigned int udplen = skb->len - dataoff;
	struct udphdr _hdr, *hdr;

	/* Header is too small? */
	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	if (hdr == NULL) {
		if (LOG_INVALID(IPPROTO_UDP))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				      "nf_ct_udp: short packet ");
		return -NF_ACCEPT;
	}

	/* Truncated/malformed packets */
	if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) {
		if (LOG_INVALID(IPPROTO_UDP))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				"nf_ct_udp: truncated/malformed packet ");
		return -NF_ACCEPT;
	}

	/* Packet with no checksum */
	if (!hdr->check)
		return NF_ACCEPT;

	/* Checksum invalid? Ignore.
	 * We skip checking packets on the outgoing path
	 * because the checksum is assumed to be correct.
	 * FIXME: Source route IP option packets --RR */
	if (nf_conntrack_checksum &&
	    ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
	     (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
	    nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
		if (LOG_INVALID(IPPROTO_UDP))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				"nf_ct_udp: bad UDP checksum ");
		return -NF_ACCEPT;
	}

	return NF_ACCEPT;
}

#ifdef CONFIG_SYSCTL
static unsigned int udp_sysctl_table_users;
static struct ctl_table_header *udp_sysctl_header;
static struct ctl_table udp_sysctl_table[] = {
	{
		.ctl_name	= NET_NF_CONNTRACK_UDP_TIMEOUT,
		.procname	= "nf_conntrack_udp_timeout",
		.data		= &nf_ct_udp_timeout,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
		.procname	= "nf_conntrack_udp_timeout_stream",
		.data		= &nf_ct_udp_timeout_stream,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= 0
	}
};
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
static struct ctl_table udp_compat_sysctl_table[] = {
	{
		.ctl_name	= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT,
		.procname	= "ip_conntrack_udp_timeout",
		.data		= &nf_ct_udp_timeout,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
		.procname	= "ip_conntrack_udp_timeout_stream",
		.data		= &nf_ct_udp_timeout_stream,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= 0
	}
};
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
#endif /* CONFIG_SYSCTL */

struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 =
{
	.l3proto		= PF_INET,
	.l4proto		= IPPROTO_UDP,
	.name			= "udp",
	.pkt_to_tuple		= udp_pkt_to_tuple,
	.invert_tuple		= udp_invert_tuple,
	.print_tuple		= udp_print_tuple,
	.print_conntrack	= udp_print_conntrack,
	.packet			= udp_packet,
	.new			= udp_new,
	.error			= udp_error,
#if defined(CONFIG_NF_CT_NETLINK) || \
    defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nfattr	= nf_ct_port_tuple_to_nfattr,
	.nfattr_to_tuple	= nf_ct_port_nfattr_to_tuple,
#endif
#ifdef CONFIG_SYSCTL
	.ctl_table_users	= &udp_sysctl_table_users,
	.ctl_table_header	= &udp_sysctl_header,
	.ctl_table		= udp_sysctl_table,
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	.ctl_compat_table	= udp_compat_sysctl_table,
#endif
#endif
};
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);

struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 =
{
	.l3proto		= PF_INET6,
	.l4proto		= IPPROTO_UDP,
	.name			= "udp",
	.pkt_to_tuple		= udp_pkt_to_tuple,
	.invert_tuple		= udp_invert_tuple,
	.print_tuple		= udp_print_tuple,
	.print_conntrack	= udp_print_conntrack,
	.packet			= udp_packet,
	.new			= udp_new,
	.error			= udp_error,
#if defined(CONFIG_NF_CT_NETLINK) || \
    defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nfattr	= nf_ct_port_tuple_to_nfattr,
	.nfattr_to_tuple	= nf_ct_port_nfattr_to_tuple,
#endif
#ifdef CONFIG_SYSCTL
	.ctl_table_users	= &udp_sysctl_table_users,
	.ctl_table_header	= &udp_sysctl_header,
	.ctl_table		= udp_sysctl_table,
#endif
};
EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);
Commit	Line	Data
9fb9cbb1 YK	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
	9	* - enable working with Layer 3 protocol independent connection tracking.
	10	*
	11	* Derived from net/ipv4/netfilter/ip_conntrack_proto_udp.c
	12	*/
	13
	14	#include <linux/types.h>
	15	#include <linux/sched.h>
	16	#include <linux/timer.h>
	17	#include <linux/module.h>
	18	#include <linux/netfilter.h>
	19	#include <linux/udp.h>
	20	#include <linux/seq_file.h>
	21	#include <linux/skbuff.h>
	22	#include <linux/ipv6.h>
	23	#include <net/ip6_checksum.h>
	24	#include <net/checksum.h>
f6180121	25
9fb9cbb1 YK	26	#include <linux/netfilter.h>
	27	#include <linux/netfilter_ipv4.h>
	28	#include <linux/netfilter_ipv6.h>
605dcad6	29	#include <net/netfilter/nf_conntrack_l4proto.h>
f6180121	30	#include <net/netfilter/nf_conntrack_ecache.h>
9fb9cbb1	31
933a41e7 PM	32	static unsigned int nf_ct_udp_timeout __read_mostly = 30*HZ;
933a41e7 PM	33	static unsigned int nf_ct_udp_timeout_stream __read_mostly = 180*HZ;
9fb9cbb1 YK	34
	35	static int udp_pkt_to_tuple(const struct sk_buff *skb,
	36	unsigned int dataoff,
	37	struct nf_conntrack_tuple *tuple)
	38	{
	39	struct udphdr _hdr, *hp;
	40
	41	/* Actually only need first 8 bytes. */
	42	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	43	if (hp == NULL)
	44	return 0;
	45
	46	tuple->src.u.udp.port = hp->source;
	47	tuple->dst.u.udp.port = hp->dest;
	48
	49	return 1;
	50	}
	51
	52	static int udp_invert_tuple(struct nf_conntrack_tuple *tuple,
	53	const struct nf_conntrack_tuple *orig)
	54	{
	55	tuple->src.u.udp.port = orig->dst.u.udp.port;
	56	tuple->dst.u.udp.port = orig->src.u.udp.port;
	57	return 1;
	58	}
	59
	60	/* Print out the per-protocol part of the tuple. */
	61	static int udp_print_tuple(struct seq_file *s,
	62	const struct nf_conntrack_tuple *tuple)
	63	{
	64	return seq_printf(s, "sport=%hu dport=%hu ",
	65	ntohs(tuple->src.u.udp.port),
	66	ntohs(tuple->dst.u.udp.port));
	67	}
	68
	69	/* Print out the private part of the conntrack. */
	70	static int udp_print_conntrack(struct seq_file *s,
	71	const struct nf_conn *conntrack)
	72	{
	73	return 0;
	74	}
	75
	76	/* Returns verdict for packet, and may modify conntracktype */
	77	static int udp_packet(struct nf_conn *conntrack,
	78	const struct sk_buff *skb,
	79	unsigned int dataoff,
	80	enum ip_conntrack_info ctinfo,
	81	int pf,
	82	unsigned int hooknum)
	83	{
	84	/* If we've seen traffic both ways, this is some kind of UDP
	85	stream. Extend timeout. */
	86	if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
	87	nf_ct_refresh_acct(conntrack, ctinfo, skb,
	88	nf_ct_udp_timeout_stream);
	89	/* Also, more likely to be important, and not a probe */
	90	if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))
	91	nf_conntrack_event_cache(IPCT_STATUS, skb);
	92	} else
	93	nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout);
	94
	95	return NF_ACCEPT;
	96	}
	97
98	/* Called when a new connection for this protocol found. */
99	static int udp_new(struct nf_conn conntrack, const struct sk_buff skb,
100	unsigned int dataoff)
101	{
102	return 1;
103	}
104
105	static int udp_error(struct sk_buff *skb, unsigned int dataoff,
106	enum ip_conntrack_info *ctinfo,
107	int pf,
96f6bf82	108	unsigned int hooknum)
9fb9cbb1 YK	109	{
	110	unsigned int udplen = skb->len - dataoff;
	111	struct udphdr _hdr, *hdr;
	112
	113	/* Header is too small? */
	114	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	115	if (hdr == NULL) {
	116	if (LOG_INVALID(IPPROTO_UDP))
	117	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	118	"nf_ct_udp: short packet ");
	119	return -NF_ACCEPT;
	120	}
	121
	122	/* Truncated/malformed packets */
	123	if (ntohs(hdr->len) > udplen \|\| ntohs(hdr->len) < sizeof(*hdr)) {
	124	if (LOG_INVALID(IPPROTO_UDP))
	125	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	126	"nf_ct_udp: truncated/malformed packet ");
	127	return -NF_ACCEPT;
	128	}
	129
	130	/* Packet with no checksum */
	131	if (!hdr->check)
	132	return NF_ACCEPT;
	133
	134	/* Checksum invalid? Ignore.
	135	* We skip checking packets on the outgoing path
84fa7933	136	* because the checksum is assumed to be correct.
9fb9cbb1	137	* FIXME: Source route IP option packets --RR */
39a27a35 PM	138	if (nf_conntrack_checksum &&
39a27a35 PM	139	((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) \|\|
96f6bf82 PM	140	(pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
96f6bf82 PM	141	nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
9fb9cbb1 YK	142	if (LOG_INVALID(IPPROTO_UDP))
	143	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	144	"nf_ct_udp: bad UDP checksum ");
	145	return -NF_ACCEPT;
	146	}
	147
	148	return NF_ACCEPT;
	149	}
	150
933a41e7 PM	151	#ifdef CONFIG_SYSCTL
	152	static unsigned int udp_sysctl_table_users;
	153	static struct ctl_table_header *udp_sysctl_header;
	154	static struct ctl_table udp_sysctl_table[] = {
	155	{
	156	.ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT,
	157	.procname = "nf_conntrack_udp_timeout",
	158	.data = &nf_ct_udp_timeout,
	159	.maxlen = sizeof(unsigned int),
	160	.mode = 0644,
	161	.proc_handler = &proc_dointvec_jiffies,
	162	},
	163	{
	164	.ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
	165	.procname = "nf_conntrack_udp_timeout_stream",
	166	.data = &nf_ct_udp_timeout_stream,
	167	.maxlen = sizeof(unsigned int),
	168	.mode = 0644,
	169	.proc_handler = &proc_dointvec_jiffies,
	170	},
	171	{
	172	.ctl_name = 0
	173	}
	174	};
a999e683 PM	175	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	176	static struct ctl_table udp_compat_sysctl_table[] = {
	177	{
	178	.ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT,
	179	.procname = "ip_conntrack_udp_timeout",
	180	.data = &nf_ct_udp_timeout,
	181	.maxlen = sizeof(unsigned int),
	182	.mode = 0644,
	183	.proc_handler = &proc_dointvec_jiffies,
	184	},
	185	{
	186	.ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
	187	.procname = "ip_conntrack_udp_timeout_stream",
	188	.data = &nf_ct_udp_timeout_stream,
	189	.maxlen = sizeof(unsigned int),
	190	.mode = 0644,
	191	.proc_handler = &proc_dointvec_jiffies,
	192	},
	193	{
	194	.ctl_name = 0
	195	}
	196	};
	197	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
933a41e7 PM	198	#endif /* CONFIG_SYSCTL */
933a41e7 PM	199
605dcad6	200	struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 =
9fb9cbb1 YK	201	{
9fb9cbb1 YK	202	.l3proto = PF_INET,
605dcad6	203	.l4proto = IPPROTO_UDP,
9fb9cbb1 YK	204	.name = "udp",
	205	.pkt_to_tuple = udp_pkt_to_tuple,
	206	.invert_tuple = udp_invert_tuple,
	207	.print_tuple = udp_print_tuple,
	208	.print_conntrack = udp_print_conntrack,
	209	.packet = udp_packet,
	210	.new = udp_new,
96f6bf82	211	.error = udp_error,
c1d10adb PNA	212	#if defined(CONFIG_NF_CT_NETLINK) \|\| \
	213	defined(CONFIG_NF_CT_NETLINK_MODULE)
	214	.tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
	215	.nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
	216	#endif
933a41e7 PM	217	#ifdef CONFIG_SYSCTL
	218	.ctl_table_users = &udp_sysctl_table_users,
	219	.ctl_table_header = &udp_sysctl_header,
	220	.ctl_table = udp_sysctl_table,
a999e683 PM	221	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	222	.ctl_compat_table = udp_compat_sysctl_table,
	223	#endif
933a41e7	224	#endif
9fb9cbb1	225	};
13b18339	226	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
9fb9cbb1	227
605dcad6	228	struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 =
9fb9cbb1 YK	229	{
9fb9cbb1 YK	230	.l3proto = PF_INET6,
605dcad6	231	.l4proto = IPPROTO_UDP,
9fb9cbb1 YK	232	.name = "udp",
	233	.pkt_to_tuple = udp_pkt_to_tuple,
	234	.invert_tuple = udp_invert_tuple,
	235	.print_tuple = udp_print_tuple,
	236	.print_conntrack = udp_print_conntrack,
	237	.packet = udp_packet,
	238	.new = udp_new,
96f6bf82	239	.error = udp_error,
c1d10adb PNA	240	#if defined(CONFIG_NF_CT_NETLINK) \|\| \
	241	defined(CONFIG_NF_CT_NETLINK_MODULE)
	242	.tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
	243	.nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
	244	#endif
933a41e7 PM	245	#ifdef CONFIG_SYSCTL
	246	.ctl_table_users = &udp_sysctl_table_users,
	247	.ctl_table_header = &udp_sysctl_header,
	248	.ctl_table = udp_sysctl_table,
	249	#endif
9fb9cbb1	250	};
13b18339	251	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);