[GitHub/mt8127/android_kernel_alcatel_ttab.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>

static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ;
static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ;

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

	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 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 1;
}

/* 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));
}

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

/* Returns verdict for packet, and may modify conntracktype */
static int udplite_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_udplite_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_udplite_timeout);

	return NF_ACCEPT;
}

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

static int udplite_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;
	unsigned int cscov;

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

	/* Checksum invalid? Ignore. */
	if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) &&
	    hooknum == NF_INET_PRE_ROUTING) {
		if (pf == PF_INET) {
			struct iphdr *iph = ip_hdr(skb);

			skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
						       udplen, IPPROTO_UDPLITE, 0);
		} else {
			struct ipv6hdr *ipv6h = ipv6_hdr(skb);
			__wsum hsum = skb_checksum(skb, 0, dataoff, 0);

			skb->csum = ~csum_unfold(
				csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
						udplen, IPPROTO_UDPLITE,
						csum_sub(0, hsum)));
		}

		skb->ip_summed = CHECKSUM_NONE;
		if (__skb_checksum_complete_head(skb, dataoff + cscov)) {
			if (LOG_INVALID(IPPROTO_UDPLITE))
				nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
					      "nf_ct_udplite: bad UDPLite "
					      "checksum ");
			return -NF_ACCEPT;
		}
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	}

	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[] = {
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nf_conntrack_udplite_timeout",
		.data		= &nf_ct_udplite_timeout,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= CTL_UNNUMBERED,
		.procname	= "nf_conntrack_udplite_timeout_stream",
		.data		= &nf_ct_udplite_timeout_stream,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec_jiffies,
	},
	{
		.ctl_name	= 0
	}
};
#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,
	.print_conntrack	= udplite_print_conntrack,
	.packet			= udplite_packet,
	.new			= udplite_new,
	.error			= udplite_error,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr	= nf_ct_port_tuple_to_nlattr,
	.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,
	.print_conntrack	= udplite_print_conntrack,
	.packet			= udplite_packet,
	.new			= udplite_new,
	.error			= udplite_error,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr	= nf_ct_port_tuple_to_nlattr,
	.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>
	25
	26	static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ;
	27	static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ;
	28
	29	static int udplite_pkt_to_tuple(const struct sk_buff *skb,
	30	unsigned int dataoff,
	31	struct nf_conntrack_tuple *tuple)
	32	{
	33	struct udphdr _hdr, *hp;
	34
	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	return 1;
	42	}
	43
	44	static int udplite_invert_tuple(struct nf_conntrack_tuple *tuple,
	45	const struct nf_conntrack_tuple *orig)
	46	{
	47	tuple->src.u.udp.port = orig->dst.u.udp.port;
	48	tuple->dst.u.udp.port = orig->src.u.udp.port;
	49	return 1;
	50	}
	51
	52	/* Print out the per-protocol part of the tuple. */
	53	static int udplite_print_tuple(struct seq_file *s,
	54	const struct nf_conntrack_tuple *tuple)
	55	{
	56	return seq_printf(s, "sport=%hu dport=%hu ",
	57	ntohs(tuple->src.u.udp.port),
	58	ntohs(tuple->dst.u.udp.port));
	59	}
	60
	61	/* Print out the private part of the conntrack. */
	62	static int udplite_print_conntrack(struct seq_file *s,
	63	const struct nf_conn *conntrack)
	64	{
	65	return 0;
	66	}
	67
	68	/* Returns verdict for packet, and may modify conntracktype */
	69	static int udplite_packet(struct nf_conn *conntrack,
	70	const struct sk_buff *skb,
	71	unsigned int dataoff,
	72	enum ip_conntrack_info ctinfo,
	73	int pf,
	74	unsigned int hooknum)
	75	{
	76	/* If we've seen traffic both ways, this is some kind of UDP
77	stream. Extend timeout. */
78	if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {
79	nf_ct_refresh_acct(conntrack, ctinfo, skb,
80	nf_ct_udplite_timeout_stream);
81	/* Also, more likely to be important, and not a probe */
82	if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))
83	nf_conntrack_event_cache(IPCT_STATUS, skb);
84	} else
85	nf_ct_refresh_acct(conntrack, ctinfo, skb,
86	nf_ct_udplite_timeout);
87
88	return NF_ACCEPT;
89	}
90
91	/* Called when a new connection for this protocol found. */
92	static int udplite_new(struct nf_conn conntrack, const struct sk_buff skb,
93	unsigned int dataoff)
94	{
95	return 1;
96	}
97
98	static int udplite_error(struct sk_buff *skb, unsigned int dataoff,
99	enum ip_conntrack_info *ctinfo,
100	int pf,
101	unsigned int hooknum)
102	{
103	unsigned int udplen = skb->len - dataoff;
104	struct udphdr _hdr, *hdr;
105	unsigned int cscov;
106
107	/* Header is too small? */
108	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
109	if (hdr == NULL) {
110	if (LOG_INVALID(IPPROTO_UDPLITE))
111	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
112	"nf_ct_udplite: short packet ");
113	return -NF_ACCEPT;
114	}
115
116	cscov = ntohs(hdr->len);
117	if (cscov == 0)
118	cscov = udplen;
119	else if (cscov < sizeof(*hdr) \|\| cscov > udplen) {
120	if (LOG_INVALID(IPPROTO_UDPLITE))
121	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
122	"nf_ct_udplite: invalid checksum coverage ");
123	return -NF_ACCEPT;
124	}
125
126	/* UDPLITE mandates checksums */
127	if (!hdr->check) {
128	if (LOG_INVALID(IPPROTO_UDPLITE))
129	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
130	"nf_ct_udplite: checksum missing ");
131	return -NF_ACCEPT;
132	}
133
134	/* Checksum invalid? Ignore. */
135	if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) &&
6e23ae2a	136	hooknum == NF_INET_PRE_ROUTING) {
59eecdfb PM	137	if (pf == PF_INET) {
	138	struct iphdr *iph = ip_hdr(skb);
	139
	140	skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
	141	udplen, IPPROTO_UDPLITE, 0);
	142	} else {
	143	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
	144	__wsum hsum = skb_checksum(skb, 0, dataoff, 0);
	145
	146	skb->csum = ~csum_unfold(
	147	csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
	148	udplen, IPPROTO_UDPLITE,
	149	csum_sub(0, hsum)));
	150	}
	151
	152	skb->ip_summed = CHECKSUM_NONE;
	153	if (__skb_checksum_complete_head(skb, dataoff + cscov)) {
	154	if (LOG_INVALID(IPPROTO_UDPLITE))
	155	nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
	156	"nf_ct_udplite: bad UDPLite "
	157	"checksum ");
	158	return -NF_ACCEPT;
	159	}
	160	skb->ip_summed = CHECKSUM_UNNECESSARY;
	161	}
	162
	163	return NF_ACCEPT;
	164	}
	165
	166	#ifdef CONFIG_SYSCTL
	167	static unsigned int udplite_sysctl_table_users;
	168	static struct ctl_table_header *udplite_sysctl_header;
	169	static struct ctl_table udplite_sysctl_table[] = {
	170	{
	171	.ctl_name = CTL_UNNUMBERED,
	172	.procname = "nf_conntrack_udplite_timeout",
	173	.data = &nf_ct_udplite_timeout,
	174	.maxlen = sizeof(unsigned int),
	175	.mode = 0644,
	176	.proc_handler = &proc_dointvec_jiffies,
	177	},
	178	{
	179	.ctl_name = CTL_UNNUMBERED,
	180	.procname = "nf_conntrack_udplite_timeout_stream",
	181	.data = &nf_ct_udplite_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_SYSCTL */
	191
	192	static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =
	193	{
	194	.l3proto = PF_INET,
	195	.l4proto = IPPROTO_UDPLITE,
	196	.name = "udplite",
	197	.pkt_to_tuple = udplite_pkt_to_tuple,
	198	.invert_tuple = udplite_invert_tuple,
	199	.print_tuple = udplite_print_tuple,
	200	.print_conntrack = udplite_print_conntrack,
201	.packet = udplite_packet,
202	.new = udplite_new,
203	.error = udplite_error,
204	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832 PM	205	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
fdf70832 PM	206	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	207	.nla_policy = nf_ct_port_nla_policy,
59eecdfb PM	208	#endif
	209	#ifdef CONFIG_SYSCTL
	210	.ctl_table_users = &udplite_sysctl_table_users,
	211	.ctl_table_header = &udplite_sysctl_header,
	212	.ctl_table = udplite_sysctl_table,
	213	#endif
	214	};
	215
	216	static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =
	217	{
	218	.l3proto = PF_INET6,
	219	.l4proto = IPPROTO_UDPLITE,
	220	.name = "udplite",
	221	.pkt_to_tuple = udplite_pkt_to_tuple,
	222	.invert_tuple = udplite_invert_tuple,
	223	.print_tuple = udplite_print_tuple,
	224	.print_conntrack = udplite_print_conntrack,
	225	.packet = udplite_packet,
	226	.new = udplite_new,
	227	.error = udplite_error,
	228	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
fdf70832 PM	229	.tuple_to_nlattr = nf_ct_port_tuple_to_nlattr,
fdf70832 PM	230	.nlattr_to_tuple = nf_ct_port_nlattr_to_tuple,
f73e924c	231	.nla_policy = nf_ct_port_nla_policy,
59eecdfb PM	232	#endif
	233	#ifdef CONFIG_SYSCTL
	234	.ctl_table_users = &udplite_sysctl_table_users,
	235	.ctl_table_header = &udplite_sysctl_header,
	236	.ctl_table = udplite_sysctl_table,
	237	#endif
	238	};
	239
	240	static int __init nf_conntrack_proto_udplite_init(void)
	241	{
	242	int err;
	243
	244	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);
	245	if (err < 0)
	246	goto err1;
	247	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);
	248	if (err < 0)
	249	goto err2;
	250	return 0;
	251	err2:
	252	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
	253	err1:
	254	return err;
	255	}
	256
	257	static void __exit nf_conntrack_proto_udplite_exit(void)
	258	{
	259	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);
	260	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);
	261	}
	262
	263	module_init(nf_conntrack_proto_udplite_init);
	264	module_exit(nf_conntrack_proto_udplite_exit);
	265
	266	MODULE_LICENSE("GPL");