[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.
 */

#include <linux/types.h>
#include <linux/timer.h>
#include <linux/module.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 __read_mostly =
{
	.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 __read_mostly =
{
	.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.
9fb9cbb1 YK	7	*/
	8
	9	#include <linux/types.h>
9fb9cbb1 YK	10	#include <linux/timer.h>
9fb9cbb1 YK	11	#include <linux/module.h>
9fb9cbb1 YK	12	#include <linux/udp.h>
	13	#include <linux/seq_file.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/ipv6.h>
	16	#include <net/ip6_checksum.h>
	17	#include <net/checksum.h>
f6180121	18
9fb9cbb1 YK	19	#include <linux/netfilter.h>
	20	#include <linux/netfilter_ipv4.h>
	21	#include <linux/netfilter_ipv6.h>
605dcad6	22	#include <net/netfilter/nf_conntrack_l4proto.h>
f6180121	23	#include <net/netfilter/nf_conntrack_ecache.h>
9fb9cbb1	24
933a41e7 PM	25	static unsigned int nf_ct_udp_timeout __read_mostly = 30*HZ;
933a41e7 PM	26	static unsigned int nf_ct_udp_timeout_stream __read_mostly = 180*HZ;
9fb9cbb1 YK	27
	28	static int udp_pkt_to_tuple(const struct sk_buff *skb,
	29	unsigned int dataoff,
	30	struct nf_conntrack_tuple *tuple)
	31	{
	32	struct udphdr _hdr, *hp;
	33
	34	/* Actually only need first 8 bytes. */
	35	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	36	if (hp == NULL)
	37	return 0;
	38
	39	tuple->src.u.udp.port = hp->source;
	40	tuple->dst.u.udp.port = hp->dest;
	41
	42	return 1;
	43	}
	44
	45	static int udp_invert_tuple(struct nf_conntrack_tuple *tuple,
	46	const struct nf_conntrack_tuple *orig)
	47	{
	48	tuple->src.u.udp.port = orig->dst.u.udp.port;
	49	tuple->dst.u.udp.port = orig->src.u.udp.port;
	50	return 1;
	51	}
	52
	53	/* Print out the per-protocol part of the tuple. */
	54	static int udp_print_tuple(struct seq_file *s,
	55	const struct nf_conntrack_tuple *tuple)
	56	{
	57	return seq_printf(s, "sport=%hu dport=%hu ",
	58	ntohs(tuple->src.u.udp.port),
	59	ntohs(tuple->dst.u.udp.port));
	60	}
	61
	62	/* Print out the private part of the conntrack. */
	63	static int udp_print_conntrack(struct seq_file *s,
	64	const struct nf_conn *conntrack)
	65	{
	66	return 0;
	67	}
	68
	69	/* Returns verdict for packet, and may modify conntracktype */
	70	static int udp_packet(struct nf_conn *conntrack,
	71	const struct sk_buff *skb,
	72	unsigned int dataoff,
	73	enum ip_conntrack_info ctinfo,
	74	int pf,
	75	unsigned int hooknum)
	76	{
	77	/* If we've seen traffic both ways, this is some kind of UDP
	78	stream. Extend timeout. */
	79	if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
	80	nf_ct_refresh_acct(conntrack, ctinfo, skb,
	81	nf_ct_udp_timeout_stream);
	82	/* Also, more likely to be important, and not a probe */
	83	if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))
	84	nf_conntrack_event_cache(IPCT_STATUS, skb);
	85	} else
	86	nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout);
	87
	88	return NF_ACCEPT;
	89	}
	90
91	/* Called when a new connection for this protocol found. */
92	static int udp_new(struct nf_conn conntrack, const struct sk_buff skb,
93	unsigned int dataoff)
94	{
95	return 1;
96	}
97
98	static int udp_error(struct sk_buff *skb, unsigned int dataoff,
99	enum ip_conntrack_info *ctinfo,
100	int pf,
96f6bf82	101	unsigned int hooknum)
9fb9cbb1 YK	102	{
	103	unsigned int udplen = skb->len - dataoff;
	104	struct udphdr _hdr, *hdr;
	105
	106	/* Header is too small? */
	107	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	108	if (hdr == NULL) {
	109	if (LOG_INVALID(IPPROTO_UDP))
	110	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	111	"nf_ct_udp: short packet ");
	112	return -NF_ACCEPT;
	113	}
	114
	115	/* Truncated/malformed packets */
	116	if (ntohs(hdr->len) > udplen \|\| ntohs(hdr->len) < sizeof(*hdr)) {
	117	if (LOG_INVALID(IPPROTO_UDP))
	118	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	119	"nf_ct_udp: truncated/malformed packet ");
	120	return -NF_ACCEPT;
	121	}
	122
	123	/* Packet with no checksum */
	124	if (!hdr->check)
	125	return NF_ACCEPT;
	126
	127	/* Checksum invalid? Ignore.
	128	* We skip checking packets on the outgoing path
84fa7933	129	* because the checksum is assumed to be correct.
9fb9cbb1	130	* FIXME: Source route IP option packets --RR */
39a27a35 PM	131	if (nf_conntrack_checksum &&
39a27a35 PM	132	((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) \|\|
96f6bf82 PM	133	(pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
96f6bf82 PM	134	nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
9fb9cbb1 YK	135	if (LOG_INVALID(IPPROTO_UDP))
	136	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	137	"nf_ct_udp: bad UDP checksum ");
	138	return -NF_ACCEPT;
	139	}
	140
	141	return NF_ACCEPT;
	142	}
	143
933a41e7 PM	144	#ifdef CONFIG_SYSCTL
	145	static unsigned int udp_sysctl_table_users;
	146	static struct ctl_table_header *udp_sysctl_header;
	147	static struct ctl_table udp_sysctl_table[] = {
	148	{
	149	.ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT,
	150	.procname = "nf_conntrack_udp_timeout",
	151	.data = &nf_ct_udp_timeout,
	152	.maxlen = sizeof(unsigned int),
	153	.mode = 0644,
	154	.proc_handler = &proc_dointvec_jiffies,
	155	},
	156	{
	157	.ctl_name = NET_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
	158	.procname = "nf_conntrack_udp_timeout_stream",
	159	.data = &nf_ct_udp_timeout_stream,
	160	.maxlen = sizeof(unsigned int),
	161	.mode = 0644,
	162	.proc_handler = &proc_dointvec_jiffies,
	163	},
	164	{
	165	.ctl_name = 0
	166	}
	167	};
a999e683 PM	168	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	169	static struct ctl_table udp_compat_sysctl_table[] = {
	170	{
	171	.ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT,
	172	.procname = "ip_conntrack_udp_timeout",
	173	.data = &nf_ct_udp_timeout,
	174	.maxlen = sizeof(unsigned int),
	175	.mode = 0644,
	176	.proc_handler = &proc_dointvec_jiffies,
	177	},
	178	{
	179	.ctl_name = NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM,
	180	.procname = "ip_conntrack_udp_timeout_stream",
	181	.data = &nf_ct_udp_timeout_stream,
	182	.maxlen = sizeof(unsigned int),
	183	.mode = 0644,
	184	.proc_handler = &proc_dointvec_jiffies,
	185	},
	186	{
	187	.ctl_name = 0
	188	}
	189	};
	190	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
933a41e7 PM	191	#endif /* CONFIG_SYSCTL */
933a41e7 PM	192
61075af5	193	struct nf_conntrack_l4proto nf_conntrack_l4proto_udp4 __read_mostly =
9fb9cbb1 YK	194	{
9fb9cbb1 YK	195	.l3proto = PF_INET,
605dcad6	196	.l4proto = IPPROTO_UDP,
9fb9cbb1 YK	197	.name = "udp",
	198	.pkt_to_tuple = udp_pkt_to_tuple,
	199	.invert_tuple = udp_invert_tuple,
	200	.print_tuple = udp_print_tuple,
	201	.print_conntrack = udp_print_conntrack,
	202	.packet = udp_packet,
	203	.new = udp_new,
96f6bf82	204	.error = udp_error,
e281db5c	205	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
c1d10adb PNA	206	.tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
	207	.nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
	208	#endif
933a41e7 PM	209	#ifdef CONFIG_SYSCTL
	210	.ctl_table_users = &udp_sysctl_table_users,
	211	.ctl_table_header = &udp_sysctl_header,
	212	.ctl_table = udp_sysctl_table,
a999e683 PM	213	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	214	.ctl_compat_table = udp_compat_sysctl_table,
	215	#endif
933a41e7	216	#endif
9fb9cbb1	217	};
13b18339	218	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp4);
9fb9cbb1	219
61075af5	220	struct nf_conntrack_l4proto nf_conntrack_l4proto_udp6 __read_mostly =
9fb9cbb1 YK	221	{
9fb9cbb1 YK	222	.l3proto = PF_INET6,
605dcad6	223	.l4proto = IPPROTO_UDP,
9fb9cbb1 YK	224	.name = "udp",
	225	.pkt_to_tuple = udp_pkt_to_tuple,
	226	.invert_tuple = udp_invert_tuple,
	227	.print_tuple = udp_print_tuple,
	228	.print_conntrack = udp_print_conntrack,
	229	.packet = udp_packet,
	230	.new = udp_new,
96f6bf82	231	.error = udp_error,
e281db5c	232	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
c1d10adb PNA	233	.tuple_to_nfattr = nf_ct_port_tuple_to_nfattr,
	234	.nfattr_to_tuple = nf_ct_port_nfattr_to_tuple,
	235	#endif
933a41e7 PM	236	#ifdef CONFIG_SYSCTL
	237	.ctl_table_users = &udp_sysctl_table_users,
	238	.ctl_table_header = &udp_sysctl_header,
	239	.ctl_table = udp_sysctl_table,
	240	#endif
9fb9cbb1	241	};
13b18339	242	EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_udp6);