[deliverable/linux.git] / net / netfilter / nf_conntrack_proto_udplite.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 * (C) 2007 Patrick McHardy <kaber@trash.net>
 *
 * 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>
#include <net/netfilter/nf_log.h>

enum udplite_conntrack {
	UDPLITE_CT_UNREPLIED,
	UDPLITE_CT_REPLIED,
	UDPLITE_CT_MAX
};

static unsigned int udplite_timeouts[UDPLITE_CT_MAX] = {
	[UDPLITE_CT_UNREPLIED]	= 30*HZ,
	[UDPLITE_CT_REPLIED]	= 180*HZ,
};

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

	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	if (hp == NULL)
		return false;

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

static bool udplite_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 true;
}

/* Print out the per-protocol part of the tuple. */
static int udplite_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));
}

/* Returns verdict for packet, and may modify conntracktype */
static int udplite_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 some kind of UDP
	   stream.  Extend timeout. */
	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
		nf_ct_refresh_acct(ct, ctinfo, skb,
				   udplite_timeouts[UDPLITE_CT_REPLIED]);
		/* 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,
				   udplite_timeouts[UDPLITE_CT_UNREPLIED]);
	}
	return NF_ACCEPT;
}

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

static int udplite_error(struct net *net, struct nf_conn *tmpl,
			 struct sk_buff *skb,
			 unsigned int dataoff,
			 enum ip_conntrack_info *ctinfo,
			 u_int8_t pf,
			 unsigned int hooknum)
{
	unsigned int udplen = skb->len - dataoff;
	const struct udphdr *hdr;
	struct udphdr _hdr;
	unsigned int cscov;

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

	cscov = ntohs(hdr->len);
	if (cscov == 0)
		cscov = udplen;
	else if (cscov < sizeof(*hdr) || cscov > udplen) {
		if (LOG_INVALID(net, IPPROTO_UDPLITE))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				"nf_ct_udplite: invalid checksum coverage ");
		return -NF_ACCEPT;
	}

	/* UDPLITE mandates checksums */
	if (!hdr->check) {
		if (LOG_INVALID(net, IPPROTO_UDPLITE))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				      "nf_ct_udplite: checksum missing ");
		return -NF_ACCEPT;
	}

	/* Checksum invalid? Ignore. */
	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
	    nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_UDP,
	    			pf)) {
		if (LOG_INVALID(net, IPPROTO_UDPLITE))
			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
				      "nf_ct_udplite: bad UDPLite checksum ");
		return -NF_ACCEPT;
	}

	return NF_ACCEPT;
}

#ifdef CONFIG_SYSCTL
static unsigned int udplite_sysctl_table_users;
static struct ctl_table_header *udplite_sysctl_header;
static struct ctl_table udplite_sysctl_table[] = {
	{
		.procname	= "nf_conntrack_udplite_timeout",
		.data		= &udplite_timeouts[UDPLITE_CT_UNREPLIED],
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{
		.procname	= "nf_conntrack_udplite_timeout_stream",
		.data		= &udplite_timeouts[UDPLITE_CT_REPLIED],
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{ }
};
#endif /* CONFIG_SYSCTL */

static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
{
	.l3proto		= PF_INET,
	.l4proto		= IPPROTO_UDPLITE,
	.name			= "udplite",
	.pkt_to_tuple		= udplite_pkt_to_tuple,
	.invert_tuple		= udplite_invert_tuple,
	.print_tuple		= udplite_print_tuple,
	.packet			= udplite_packet,
	.new			= udplite_new,
	.error			= udplite_error,
#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_SYSCTL
	.ctl_table_users	= &udplite_sysctl_table_users,
	.ctl_table_header	= &udplite_sysctl_header,
	.ctl_table		= udplite_sysctl_table,
#endif
};

static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
{
	.l3proto		= PF_INET6,
	.l4proto		= IPPROTO_UDPLITE,
	.name			= "udplite",
	.pkt_to_tuple		= udplite_pkt_to_tuple,
	.invert_tuple		= udplite_invert_tuple,
	.print_tuple		= udplite_print_tuple,
	.packet			= udplite_packet,
	.new			= udplite_new,
	.error			= udplite_error,
#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_SYSCTL
	.ctl_table_users	= &udplite_sysctl_table_users,
	.ctl_table_header	= &udplite_sysctl_header,
	.ctl_table		= udplite_sysctl_table,
#endif
};

static int __init nf_conntrack_proto_udplite_init(void)
{
	int err;

	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
	if (err < 0)
		goto err1;
	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
	if (err < 0)
		goto err2;
	return 0;
err2:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
err1:
	return err;
}

static void __exit nf_conntrack_proto_udplite_exit(void)
{
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
}

module_init(nf_conntrack_proto_udplite_init);
module_exit(nf_conntrack_proto_udplite_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
59eecdfb PM	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	3	* (C) 2007 Patrick McHardy <kaber@trash.net>
	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.
	8	*/
	9
	10	#include <linux/types.h>
	11	#include <linux/timer.h>
	12	#include <linux/module.h>
59eecdfb PM	13	#include <linux/udp.h>
	14	#include <linux/seq_file.h>
	15	#include <linux/skbuff.h>
	16	#include <linux/ipv6.h>
	17	#include <net/ip6_checksum.h>
	18	#include <net/checksum.h>
	19
	20	#include <linux/netfilter.h>
	21	#include <linux/netfilter_ipv4.h>
	22	#include <linux/netfilter_ipv6.h>
	23	#include <net/netfilter/nf_conntrack_l4proto.h>
	24	#include <net/netfilter/nf_conntrack_ecache.h>
f01ffbd6	25	#include <net/netfilter/nf_log.h>
59eecdfb	26
5a41db94 PNA	27	enum udplite_conntrack {
	28	UDPLITE_CT_UNREPLIED,
	29	UDPLITE_CT_REPLIED,
	30	UDPLITE_CT_MAX
	31	};
	32
	33	static unsigned int udplite_timeouts[UDPLITE_CT_MAX] = {
	34	[UDPLITE_CT_UNREPLIED] = 30*HZ,
	35	[UDPLITE_CT_REPLIED] = 180*HZ,
	36	};
59eecdfb	37
09f263cd JE	38	static bool udplite_pkt_to_tuple(const struct sk_buff *skb,
	39	unsigned int dataoff,
	40	struct nf_conntrack_tuple *tuple)
59eecdfb	41	{
da3f13c9 JE	42	const struct udphdr *hp;
da3f13c9 JE	43	struct udphdr _hdr;
59eecdfb PM	44
	45	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	46	if (hp == NULL)
09f263cd	47	return false;
59eecdfb PM	48
	49	tuple->src.u.udp.port = hp->source;
	50	tuple->dst.u.udp.port = hp->dest;
09f263cd	51	return true;
59eecdfb PM	52	}
59eecdfb PM	53
09f263cd JE	54	static bool udplite_invert_tuple(struct nf_conntrack_tuple *tuple,
09f263cd JE	55	const struct nf_conntrack_tuple *orig)
59eecdfb PM	56	{
	57	tuple->src.u.udp.port = orig->dst.u.udp.port;
	58	tuple->dst.u.udp.port = orig->src.u.udp.port;
09f263cd	59	return true;
59eecdfb PM	60	}
	61
	62	/* Print out the per-protocol part of the tuple. */
	63	static int udplite_print_tuple(struct seq_file *s,
	64	const struct nf_conntrack_tuple *tuple)
	65	{
	66	return seq_printf(s, "sport=%hu dport=%hu ",
	67	ntohs(tuple->src.u.udp.port),
	68	ntohs(tuple->dst.u.udp.port));
	69	}
	70
59eecdfb	71	/* Returns verdict for packet, and may modify conntracktype */
c88130bc	72	static int udplite_packet(struct nf_conn *ct,
59eecdfb PM	73	const struct sk_buff *skb,
	74	unsigned int dataoff,
	75	enum ip_conntrack_info ctinfo,
76108cea	76	u_int8_t pf,
59eecdfb PM	77	unsigned int hooknum)
	78	{
	79	/* If we've seen traffic both ways, this is some kind of UDP
	80	stream. Extend timeout. */
c88130bc PM	81	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
c88130bc PM	82	nf_ct_refresh_acct(ct, ctinfo, skb,
5a41db94	83	udplite_timeouts[UDPLITE_CT_REPLIED]);
59eecdfb	84	/* Also, more likely to be important, and not a probe */
c88130bc	85	if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
858b3133	86	nf_conntrack_event_cache(IPCT_ASSURED, ct);
5a41db94 PNA	87	} else {
	88	nf_ct_refresh_acct(ct, ctinfo, skb,
	89	udplite_timeouts[UDPLITE_CT_UNREPLIED]);
	90	}
59eecdfb PM	91	return NF_ACCEPT;
	92	}
	93
	94	/* Called when a new connection for this protocol found. */
09f263cd JE	95	static bool udplite_new(struct nf_conn ct, const struct sk_buff skb,
09f263cd JE	96	unsigned int dataoff)
59eecdfb	97	{
09f263cd	98	return true;
59eecdfb PM	99	}
59eecdfb PM	100
8fea97ec	101	static int udplite_error(struct net net, struct nf_conn tmpl,
74c51a14 AD	102	struct sk_buff *skb,
74c51a14 AD	103	unsigned int dataoff,
59eecdfb	104	enum ip_conntrack_info *ctinfo,
76108cea	105	u_int8_t pf,
59eecdfb PM	106	unsigned int hooknum)
	107	{
	108	unsigned int udplen = skb->len - dataoff;
da3f13c9 JE	109	const struct udphdr *hdr;
da3f13c9 JE	110	struct udphdr _hdr;
59eecdfb PM	111	unsigned int cscov;
	112
	113	/* Header is too small? */
	114	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	115	if (hdr == NULL) {
c2a2c7e0	116	if (LOG_INVALID(net, IPPROTO_UDPLITE))
59eecdfb PM	117	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	118	"nf_ct_udplite: short packet ");
	119	return -NF_ACCEPT;
	120	}
	121
	122	cscov = ntohs(hdr->len);
	123	if (cscov == 0)
	124	cscov = udplen;
	125	else if (cscov < sizeof(*hdr) \|\| cscov > udplen) {
c2a2c7e0	126	if (LOG_INVALID(net, IPPROTO_UDPLITE))
59eecdfb PM	127	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	128	"nf_ct_udplite: invalid checksum coverage ");
	129	return -NF_ACCEPT;
	130	}
	131
	132	/* UDPLITE mandates checksums */
	133	if (!hdr->check) {
c2a2c7e0	134	if (LOG_INVALID(net, IPPROTO_UDPLITE))
59eecdfb PM	135	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	136	"nf_ct_udplite: checksum missing ");
	137	return -NF_ACCEPT;
	138	}
	139
	140	/* Checksum invalid? Ignore. */
c04d0552	141	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
d63a6507 PM	142	nf_checksum_partial(skb, hooknum, dataoff, cscov, IPPROTO_UDP,
d63a6507 PM	143	pf)) {
c2a2c7e0	144	if (LOG_INVALID(net, IPPROTO_UDPLITE))
d63a6507 PM	145	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	146	"nf_ct_udplite: bad UDPLite checksum ");
	147	return -NF_ACCEPT;
59eecdfb PM	148	}
	149
	150	return NF_ACCEPT;
	151	}
	152
	153	#ifdef CONFIG_SYSCTL
	154	static unsigned int udplite_sysctl_table_users;
	155	static struct ctl_table_header *udplite_sysctl_header;
	156	static struct ctl_table udplite_sysctl_table[] = {
	157	{
59eecdfb	158	.procname = "nf_conntrack_udplite_timeout",
5a41db94	159	.data = &udplite_timeouts[UDPLITE_CT_UNREPLIED],
59eecdfb PM	160	.maxlen = sizeof(unsigned int),
59eecdfb PM	161	.mode = 0644,
6d9f239a	162	.proc_handler = proc_dointvec_jiffies,
59eecdfb PM	163	},
59eecdfb PM	164	{
59eecdfb	165	.procname = "nf_conntrack_udplite_timeout_stream",
5a41db94	166	.data = &udplite_timeouts[UDPLITE_CT_REPLIED],
59eecdfb PM	167	.maxlen = sizeof(unsigned int),
59eecdfb PM	168	.mode = 0644,
6d9f239a	169	.proc_handler = proc_dointvec_jiffies,
59eecdfb	170	},
f8572d8f	171	{ }
59eecdfb PM	172	};
	173	#endif /* CONFIG_SYSCTL */
	174
	175	static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
	176	{
	177	.l3proto = PF_INET,
	178	.l4proto = IPPROTO_UDPLITE,
	179	.name = "udplite",
	180	.pkt_to_tuple = udplite_pkt_to_tuple,
	181	.invert_tuple = udplite_invert_tuple,
	182	.print_tuple = udplite_print_tuple,
59eecdfb PM	183	.packet = udplite_packet,
	184	.new = udplite_new,
	185	.error = udplite_error,
c0cd1156	186	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
fdf70832	187	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
a400c30e	188	.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
fdf70832	189	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	190	.nla_policy = nf_ct_port_nla_policy,
59eecdfb PM	191	#endif
	192	#ifdef CONFIG_SYSCTL
	193	.ctl_table_users = &udplite_sysctl_table_users,
	194	.ctl_table_header = &udplite_sysctl_header,
	195	.ctl_table = udplite_sysctl_table,
	196	#endif
	197	};
	198
	199	static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
	200	{
	201	.l3proto = PF_INET6,
	202	.l4proto = IPPROTO_UDPLITE,
	203	.name = "udplite",
	204	.pkt_to_tuple = udplite_pkt_to_tuple,
	205	.invert_tuple = udplite_invert_tuple,
	206	.print_tuple = udplite_print_tuple,
59eecdfb PM	207	.packet = udplite_packet,
	208	.new = udplite_new,
	209	.error = udplite_error,
c0cd1156	210	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
fdf70832	211	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
5ff48294	212	.nlattr_tuple_size = nf_ct_port_nlattr_tuple_size,
fdf70832	213	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	214	.nla_policy = nf_ct_port_nla_policy,
59eecdfb PM	215	#endif
	216	#ifdef CONFIG_SYSCTL
	217	.ctl_table_users = &udplite_sysctl_table_users,
	218	.ctl_table_header = &udplite_sysctl_header,
	219	.ctl_table = udplite_sysctl_table,
	220	#endif
	221	};
	222
	223	static int __init nf_conntrack_proto_udplite_init(void)
	224	{
	225	int err;
	226
	227	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
	228	if (err < 0)
	229	goto err1;
	230	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
	231	if (err < 0)
	232	goto err2;
	233	return 0;
	234	err2:
	235	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
	236	err1:
	237	return err;
	238	}
	239
	240	static void __exit nf_conntrack_proto_udplite_exit(void)
	241	{
	242	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
	243	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
	244	}
	245
	246	module_init(nf_conntrack_proto_udplite_init);
	247	module_exit(nf_conntrack_proto_udplite_exit);
	248
	249	MODULE_LICENSE("GPL");