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v5.14.15
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Transparent proxy support for Linux/iptables
  4 *
  5 * Copyright (C) 2007-2008 BalaBit IT Ltd.
  6 * Author: Krisztian Kovacs
 
 
 
 
 
  7 */
  8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  9#include <linux/module.h>
 10#include <linux/skbuff.h>
 11#include <linux/netfilter/x_tables.h>
 12#include <linux/netfilter_ipv4/ip_tables.h>
 13#include <net/tcp.h>
 14#include <net/udp.h>
 15#include <net/icmp.h>
 16#include <net/sock.h>
 17#include <net/inet_sock.h>
 
 18#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
 19
 20#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 
 21#include <linux/netfilter_ipv6/ip6_tables.h>
 22#include <net/inet6_hashtables.h>
 23#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 24#endif
 25
 26#include <net/netfilter/nf_socket.h>
 27#include <linux/netfilter/xt_socket.h>
 28
 29/* "socket" match based redirection (no specific rule)
 30 * ===================================================
 31 *
 32 * There are connections with dynamic endpoints (e.g. FTP data
 33 * connection) that the user is unable to add explicit rules
 34 * for. These are taken care of by a generic "socket" rule. It is
 35 * assumed that the proxy application is trusted to open such
 36 * connections without explicit iptables rule (except of course the
 37 * generic 'socket' rule). In this case the following sockets are
 38 * matched in preference order:
 39 *
 40 *   - match: if there's a fully established connection matching the
 41 *     _packet_ tuple
 42 *
 43 *   - match: if there's a non-zero bound listener (possibly with a
 44 *     non-local address) We don't accept zero-bound listeners, since
 45 *     then local services could intercept traffic going through the
 46 *     box.
 47 */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 48static bool
 49socket_match(const struct sk_buff *skb, struct xt_action_param *par,
 50	     const struct xt_socket_mtinfo1 *info)
 51{
 52	struct sk_buff *pskb = (struct sk_buff *)skb;
 53	struct sock *sk = skb->sk;
 
 
 
 
 
 
 
 
 54
 55	if (sk && !net_eq(xt_net(par), sock_net(sk)))
 56		sk = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 57
 58	if (!sk)
 59		sk = nf_sk_lookup_slow_v4(xt_net(par), skb, xt_in(par));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 60
 61	if (sk) {
 
 
 62		bool wildcard;
 63		bool transparent = true;
 64
 65		/* Ignore sockets listening on INADDR_ANY,
 66		 * unless XT_SOCKET_NOWILDCARD is set
 67		 */
 68		wildcard = (!(info->flags & XT_SOCKET_NOWILDCARD) &&
 69			    sk_fullsock(sk) &&
 70			    inet_sk(sk)->inet_rcv_saddr == 0);
 71
 72		/* Ignore non-transparent sockets,
 73		 * if XT_SOCKET_TRANSPARENT is used
 74		 */
 75		if (info->flags & XT_SOCKET_TRANSPARENT)
 76			transparent = inet_sk_transparent(sk);
 77
 78		if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
 79		    transparent && sk_fullsock(sk))
 80			pskb->mark = sk->sk_mark;
 81
 82		if (sk != skb->sk)
 83			sock_gen_put(sk);
 84
 85		if (wildcard || !transparent)
 86			sk = NULL;
 87	}
 88
 89	return sk != NULL;
 
 
 
 
 
 90}
 91
 92static bool
 93socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
 94{
 95	static struct xt_socket_mtinfo1 xt_info_v0 = {
 96		.flags = 0,
 97	};
 98
 99	return socket_match(skb, par, &xt_info_v0);
100}
101
102static bool
103socket_mt4_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
104{
105	return socket_match(skb, par, par->matchinfo);
106}
107
108#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
109static bool
110socket_mt6_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
111{
 
 
 
 
 
 
112	const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
113	struct sk_buff *pskb = (struct sk_buff *)skb;
114	struct sock *sk = skb->sk;
115
116	if (sk && !net_eq(xt_net(par), sock_net(sk)))
117		sk = NULL;
 
 
 
118
119	if (!sk)
120		sk = nf_sk_lookup_slow_v6(xt_net(par), skb, xt_in(par));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
121
122	if (sk) {
 
 
123		bool wildcard;
124		bool transparent = true;
125
126		/* Ignore sockets listening on INADDR_ANY
127		 * unless XT_SOCKET_NOWILDCARD is set
128		 */
129		wildcard = (!(info->flags & XT_SOCKET_NOWILDCARD) &&
130			    sk_fullsock(sk) &&
131			    ipv6_addr_any(&sk->sk_v6_rcv_saddr));
132
133		/* Ignore non-transparent sockets,
134		 * if XT_SOCKET_TRANSPARENT is used
135		 */
136		if (info->flags & XT_SOCKET_TRANSPARENT)
137			transparent = inet_sk_transparent(sk);
138
139		if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
140		    transparent && sk_fullsock(sk))
141			pskb->mark = sk->sk_mark;
142
143		if (sk != skb->sk)
144			sock_gen_put(sk);
145
146		if (wildcard || !transparent)
147			sk = NULL;
148	}
149
150	return sk != NULL;
151}
152#endif
153
154static int socket_mt_enable_defrag(struct net *net, int family)
155{
156	switch (family) {
157	case NFPROTO_IPV4:
158		return nf_defrag_ipv4_enable(net);
159#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
160	case NFPROTO_IPV6:
161		return nf_defrag_ipv6_enable(net);
162#endif
163	}
164	WARN_ONCE(1, "Unknown family %d\n", family);
165	return 0;
166}
167
168static int socket_mt_v1_check(const struct xt_mtchk_param *par)
169{
170	const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
171	int err;
172
173	err = socket_mt_enable_defrag(par->net, par->family);
174	if (err)
175		return err;
176
177	if (info->flags & ~XT_SOCKET_FLAGS_V1) {
178		pr_info_ratelimited("unknown flags 0x%x\n",
179				    info->flags & ~XT_SOCKET_FLAGS_V1);
180		return -EINVAL;
181	}
182	return 0;
183}
184
185static int socket_mt_v2_check(const struct xt_mtchk_param *par)
186{
187	const struct xt_socket_mtinfo2 *info = (struct xt_socket_mtinfo2 *) par->matchinfo;
188	int err;
189
190	err = socket_mt_enable_defrag(par->net, par->family);
191	if (err)
192		return err;
193
194	if (info->flags & ~XT_SOCKET_FLAGS_V2) {
195		pr_info_ratelimited("unknown flags 0x%x\n",
196				    info->flags & ~XT_SOCKET_FLAGS_V2);
197		return -EINVAL;
198	}
199	return 0;
200}
201
202static int socket_mt_v3_check(const struct xt_mtchk_param *par)
203{
204	const struct xt_socket_mtinfo3 *info =
205				    (struct xt_socket_mtinfo3 *)par->matchinfo;
206	int err;
207
208	err = socket_mt_enable_defrag(par->net, par->family);
209	if (err)
210		return err;
211	if (info->flags & ~XT_SOCKET_FLAGS_V3) {
212		pr_info_ratelimited("unknown flags 0x%x\n",
213				    info->flags & ~XT_SOCKET_FLAGS_V3);
214		return -EINVAL;
215	}
216	return 0;
217}
218
219static void socket_mt_destroy(const struct xt_mtdtor_param *par)
220{
221	if (par->family == NFPROTO_IPV4)
222		nf_defrag_ipv4_disable(par->net);
223	else if (par->family == NFPROTO_IPV6)
224		nf_defrag_ipv4_disable(par->net);
225}
 
226
227static struct xt_match socket_mt_reg[] __read_mostly = {
228	{
229		.name		= "socket",
230		.revision	= 0,
231		.family		= NFPROTO_IPV4,
232		.match		= socket_mt4_v0,
233		.hooks		= (1 << NF_INET_PRE_ROUTING) |
234				  (1 << NF_INET_LOCAL_IN),
235		.me		= THIS_MODULE,
236	},
237	{
238		.name		= "socket",
239		.revision	= 1,
240		.family		= NFPROTO_IPV4,
241		.match		= socket_mt4_v1_v2_v3,
242		.destroy	= socket_mt_destroy,
243		.checkentry	= socket_mt_v1_check,
244		.matchsize	= sizeof(struct xt_socket_mtinfo1),
245		.hooks		= (1 << NF_INET_PRE_ROUTING) |
246				  (1 << NF_INET_LOCAL_IN),
247		.me		= THIS_MODULE,
248	},
249#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
250	{
251		.name		= "socket",
252		.revision	= 1,
253		.family		= NFPROTO_IPV6,
254		.match		= socket_mt6_v1_v2_v3,
255		.checkentry	= socket_mt_v1_check,
256		.matchsize	= sizeof(struct xt_socket_mtinfo1),
257		.destroy	= socket_mt_destroy,
258		.hooks		= (1 << NF_INET_PRE_ROUTING) |
259				  (1 << NF_INET_LOCAL_IN),
260		.me		= THIS_MODULE,
261	},
262#endif
263	{
264		.name		= "socket",
265		.revision	= 2,
266		.family		= NFPROTO_IPV4,
267		.match		= socket_mt4_v1_v2_v3,
268		.checkentry	= socket_mt_v2_check,
269		.destroy	= socket_mt_destroy,
270		.matchsize	= sizeof(struct xt_socket_mtinfo1),
271		.hooks		= (1 << NF_INET_PRE_ROUTING) |
272				  (1 << NF_INET_LOCAL_IN),
273		.me		= THIS_MODULE,
274	},
275#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
276	{
277		.name		= "socket",
278		.revision	= 2,
279		.family		= NFPROTO_IPV6,
280		.match		= socket_mt6_v1_v2_v3,
281		.checkentry	= socket_mt_v2_check,
282		.destroy	= socket_mt_destroy,
283		.matchsize	= sizeof(struct xt_socket_mtinfo1),
284		.hooks		= (1 << NF_INET_PRE_ROUTING) |
285				  (1 << NF_INET_LOCAL_IN),
286		.me		= THIS_MODULE,
287	},
288#endif
289	{
290		.name		= "socket",
291		.revision	= 3,
292		.family		= NFPROTO_IPV4,
293		.match		= socket_mt4_v1_v2_v3,
294		.checkentry	= socket_mt_v3_check,
295		.destroy	= socket_mt_destroy,
296		.matchsize	= sizeof(struct xt_socket_mtinfo1),
297		.hooks		= (1 << NF_INET_PRE_ROUTING) |
298				  (1 << NF_INET_LOCAL_IN),
299		.me		= THIS_MODULE,
300	},
301#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
302	{
303		.name		= "socket",
304		.revision	= 3,
305		.family		= NFPROTO_IPV6,
306		.match		= socket_mt6_v1_v2_v3,
307		.checkentry	= socket_mt_v3_check,
308		.destroy	= socket_mt_destroy,
309		.matchsize	= sizeof(struct xt_socket_mtinfo1),
310		.hooks		= (1 << NF_INET_PRE_ROUTING) |
311				  (1 << NF_INET_LOCAL_IN),
312		.me		= THIS_MODULE,
313	},
314#endif
315};
316
317static int __init socket_mt_init(void)
318{
 
 
 
 
 
319	return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
320}
321
322static void __exit socket_mt_exit(void)
323{
324	xt_unregister_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
325}
326
327module_init(socket_mt_init);
328module_exit(socket_mt_exit);
329
330MODULE_LICENSE("GPL");
331MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
332MODULE_DESCRIPTION("x_tables socket match module");
333MODULE_ALIAS("ipt_socket");
334MODULE_ALIAS("ip6t_socket");
v3.1
 
  1/*
  2 * Transparent proxy support for Linux/iptables
  3 *
  4 * Copyright (C) 2007-2008 BalaBit IT Ltd.
  5 * Author: Krisztian Kovacs
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 *
 11 */
 12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13#include <linux/module.h>
 14#include <linux/skbuff.h>
 15#include <linux/netfilter/x_tables.h>
 16#include <linux/netfilter_ipv4/ip_tables.h>
 17#include <net/tcp.h>
 18#include <net/udp.h>
 19#include <net/icmp.h>
 20#include <net/sock.h>
 21#include <net/inet_sock.h>
 22#include <net/netfilter/nf_tproxy_core.h>
 23#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
 24
 25#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
 26#define XT_SOCKET_HAVE_IPV6 1
 27#include <linux/netfilter_ipv6/ip6_tables.h>
 
 28#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
 29#endif
 30
 
 31#include <linux/netfilter/xt_socket.h>
 32
 33#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 34#define XT_SOCKET_HAVE_CONNTRACK 1
 35#include <net/netfilter/nf_conntrack.h>
 36#endif
 37
 38static void
 39xt_socket_put_sk(struct sock *sk)
 40{
 41	if (sk->sk_state == TCP_TIME_WAIT)
 42		inet_twsk_put(inet_twsk(sk));
 43	else
 44		sock_put(sk);
 45}
 46
 47static int
 48extract_icmp4_fields(const struct sk_buff *skb,
 49		    u8 *protocol,
 50		    __be32 *raddr,
 51		    __be32 *laddr,
 52		    __be16 *rport,
 53		    __be16 *lport)
 54{
 55	unsigned int outside_hdrlen = ip_hdrlen(skb);
 56	struct iphdr *inside_iph, _inside_iph;
 57	struct icmphdr *icmph, _icmph;
 58	__be16 *ports, _ports[2];
 59
 60	icmph = skb_header_pointer(skb, outside_hdrlen,
 61				   sizeof(_icmph), &_icmph);
 62	if (icmph == NULL)
 63		return 1;
 64
 65	switch (icmph->type) {
 66	case ICMP_DEST_UNREACH:
 67	case ICMP_SOURCE_QUENCH:
 68	case ICMP_REDIRECT:
 69	case ICMP_TIME_EXCEEDED:
 70	case ICMP_PARAMETERPROB:
 71		break;
 72	default:
 73		return 1;
 74	}
 75
 76	inside_iph = skb_header_pointer(skb, outside_hdrlen +
 77					sizeof(struct icmphdr),
 78					sizeof(_inside_iph), &_inside_iph);
 79	if (inside_iph == NULL)
 80		return 1;
 81
 82	if (inside_iph->protocol != IPPROTO_TCP &&
 83	    inside_iph->protocol != IPPROTO_UDP)
 84		return 1;
 85
 86	ports = skb_header_pointer(skb, outside_hdrlen +
 87				   sizeof(struct icmphdr) +
 88				   (inside_iph->ihl << 2),
 89				   sizeof(_ports), &_ports);
 90	if (ports == NULL)
 91		return 1;
 92
 93	/* the inside IP packet is the one quoted from our side, thus
 94	 * its saddr is the local address */
 95	*protocol = inside_iph->protocol;
 96	*laddr = inside_iph->saddr;
 97	*lport = ports[0];
 98	*raddr = inside_iph->daddr;
 99	*rport = ports[1];
100
101	return 0;
102}
103
104static bool
105socket_match(const struct sk_buff *skb, struct xt_action_param *par,
106	     const struct xt_socket_mtinfo1 *info)
107{
108	const struct iphdr *iph = ip_hdr(skb);
109	struct udphdr _hdr, *hp = NULL;
110	struct sock *sk;
111	__be32 daddr, saddr;
112	__be16 dport, sport;
113	u8 protocol;
114#ifdef XT_SOCKET_HAVE_CONNTRACK
115	struct nf_conn const *ct;
116	enum ip_conntrack_info ctinfo;
117#endif
118
119	if (iph->protocol == IPPROTO_UDP || iph->protocol == IPPROTO_TCP) {
120		hp = skb_header_pointer(skb, ip_hdrlen(skb),
121					sizeof(_hdr), &_hdr);
122		if (hp == NULL)
123			return false;
124
125		protocol = iph->protocol;
126		saddr = iph->saddr;
127		sport = hp->source;
128		daddr = iph->daddr;
129		dport = hp->dest;
130
131	} else if (iph->protocol == IPPROTO_ICMP) {
132		if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
133					&sport, &dport))
134			return false;
135	} else {
136		return false;
137	}
138
139#ifdef XT_SOCKET_HAVE_CONNTRACK
140	/* Do the lookup with the original socket address in case this is a
141	 * reply packet of an established SNAT-ted connection. */
142
143	ct = nf_ct_get(skb, &ctinfo);
144	if (ct && !nf_ct_is_untracked(ct) &&
145	    ((iph->protocol != IPPROTO_ICMP &&
146	      ctinfo == IP_CT_ESTABLISHED_REPLY) ||
147	     (iph->protocol == IPPROTO_ICMP &&
148	      ctinfo == IP_CT_RELATED_REPLY)) &&
149	    (ct->status & IPS_SRC_NAT_DONE)) {
150
151		daddr = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip;
152		dport = (iph->protocol == IPPROTO_TCP) ?
153			ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.tcp.port :
154			ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
155	}
156#endif
157
158	sk = nf_tproxy_get_sock_v4(dev_net(skb->dev), protocol,
159				   saddr, daddr, sport, dport, par->in, NFT_LOOKUP_ANY);
160	if (sk != NULL) {
161		bool wildcard;
162		bool transparent = true;
163
164		/* Ignore sockets listening on INADDR_ANY */
165		wildcard = (sk->sk_state != TCP_TIME_WAIT &&
 
 
 
166			    inet_sk(sk)->inet_rcv_saddr == 0);
167
168		/* Ignore non-transparent sockets,
169		   if XT_SOCKET_TRANSPARENT is used */
170		if (info && info->flags & XT_SOCKET_TRANSPARENT)
171			transparent = ((sk->sk_state != TCP_TIME_WAIT &&
172					inet_sk(sk)->transparent) ||
173				       (sk->sk_state == TCP_TIME_WAIT &&
174					inet_twsk(sk)->tw_transparent));
 
 
175
176		xt_socket_put_sk(sk);
 
177
178		if (wildcard || !transparent)
179			sk = NULL;
180	}
181
182	pr_debug("proto %hhu %pI4:%hu -> %pI4:%hu (orig %pI4:%hu) sock %p\n",
183		 protocol, &saddr, ntohs(sport),
184		 &daddr, ntohs(dport),
185		 &iph->daddr, hp ? ntohs(hp->dest) : 0, sk);
186
187	return (sk != NULL);
188}
189
190static bool
191socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
192{
193	return socket_match(skb, par, NULL);
 
 
 
 
194}
195
196static bool
197socket_mt4_v1(const struct sk_buff *skb, struct xt_action_param *par)
198{
199	return socket_match(skb, par, par->matchinfo);
200}
201
202#ifdef XT_SOCKET_HAVE_IPV6
203
204static int
205extract_icmp6_fields(const struct sk_buff *skb,
206		     unsigned int outside_hdrlen,
207		     int *protocol,
208		     struct in6_addr **raddr,
209		     struct in6_addr **laddr,
210		     __be16 *rport,
211		     __be16 *lport)
212{
213	struct ipv6hdr *inside_iph, _inside_iph;
214	struct icmp6hdr *icmph, _icmph;
215	__be16 *ports, _ports[2];
216	u8 inside_nexthdr;
217	int inside_hdrlen;
218
219	icmph = skb_header_pointer(skb, outside_hdrlen,
220				   sizeof(_icmph), &_icmph);
221	if (icmph == NULL)
222		return 1;
223
224	if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK)
225		return 1;
226
227	inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph), sizeof(_inside_iph), &_inside_iph);
228	if (inside_iph == NULL)
229		return 1;
230	inside_nexthdr = inside_iph->nexthdr;
231
232	inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) + sizeof(_inside_iph), &inside_nexthdr);
233	if (inside_hdrlen < 0)
234		return 1; /* hjm: Packet has no/incomplete transport layer headers. */
235
236	if (inside_nexthdr != IPPROTO_TCP &&
237	    inside_nexthdr != IPPROTO_UDP)
238		return 1;
239
240	ports = skb_header_pointer(skb, inside_hdrlen,
241				   sizeof(_ports), &_ports);
242	if (ports == NULL)
243		return 1;
244
245	/* the inside IP packet is the one quoted from our side, thus
246	 * its saddr is the local address */
247	*protocol = inside_nexthdr;
248	*laddr = &inside_iph->saddr;
249	*lport = ports[0];
250	*raddr = &inside_iph->daddr;
251	*rport = ports[1];
252
253	return 0;
254}
255
256static bool
257socket_mt6_v1(const struct sk_buff *skb, struct xt_action_param *par)
258{
259	struct ipv6hdr *iph = ipv6_hdr(skb);
260	struct udphdr _hdr, *hp = NULL;
261	struct sock *sk;
262	struct in6_addr *daddr, *saddr;
263	__be16 dport, sport;
264	int thoff, tproto;
265	const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
 
 
266
267	tproto = ipv6_find_hdr(skb, &thoff, -1, NULL);
268	if (tproto < 0) {
269		pr_debug("unable to find transport header in IPv6 packet, dropping\n");
270		return NF_DROP;
271	}
272
273	if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) {
274		hp = skb_header_pointer(skb, thoff,
275					sizeof(_hdr), &_hdr);
276		if (hp == NULL)
277			return false;
278
279		saddr = &iph->saddr;
280		sport = hp->source;
281		daddr = &iph->daddr;
282		dport = hp->dest;
283
284	} else if (tproto == IPPROTO_ICMPV6) {
285		if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr,
286					 &sport, &dport))
287			return false;
288	} else {
289		return false;
290	}
291
292	sk = nf_tproxy_get_sock_v6(dev_net(skb->dev), tproto,
293				   saddr, daddr, sport, dport, par->in, NFT_LOOKUP_ANY);
294	if (sk != NULL) {
295		bool wildcard;
296		bool transparent = true;
297
298		/* Ignore sockets listening on INADDR_ANY */
299		wildcard = (sk->sk_state != TCP_TIME_WAIT &&
300			    ipv6_addr_any(&inet6_sk(sk)->rcv_saddr));
 
 
 
301
302		/* Ignore non-transparent sockets,
303		   if XT_SOCKET_TRANSPARENT is used */
304		if (info && info->flags & XT_SOCKET_TRANSPARENT)
305			transparent = ((sk->sk_state != TCP_TIME_WAIT &&
306					inet_sk(sk)->transparent) ||
307				       (sk->sk_state == TCP_TIME_WAIT &&
308					inet_twsk(sk)->tw_transparent));
 
 
309
310		xt_socket_put_sk(sk);
 
311
312		if (wildcard || !transparent)
313			sk = NULL;
314	}
315
316	pr_debug("proto %hhd %pI6:%hu -> %pI6:%hu "
317		 "(orig %pI6:%hu) sock %p\n",
318		 tproto, saddr, ntohs(sport),
319		 daddr, ntohs(dport),
320		 &iph->daddr, hp ? ntohs(hp->dest) : 0, sk);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
321
322	return (sk != NULL);
 
 
 
 
 
323}
324#endif
325
326static struct xt_match socket_mt_reg[] __read_mostly = {
327	{
328		.name		= "socket",
329		.revision	= 0,
330		.family		= NFPROTO_IPV4,
331		.match		= socket_mt4_v0,
332		.hooks		= (1 << NF_INET_PRE_ROUTING) |
333				  (1 << NF_INET_LOCAL_IN),
334		.me		= THIS_MODULE,
335	},
336	{
337		.name		= "socket",
338		.revision	= 1,
339		.family		= NFPROTO_IPV4,
340		.match		= socket_mt4_v1,
 
 
341		.matchsize	= sizeof(struct xt_socket_mtinfo1),
342		.hooks		= (1 << NF_INET_PRE_ROUTING) |
343				  (1 << NF_INET_LOCAL_IN),
344		.me		= THIS_MODULE,
345	},
346#ifdef XT_SOCKET_HAVE_IPV6
347	{
348		.name		= "socket",
349		.revision	= 1,
350		.family		= NFPROTO_IPV6,
351		.match		= socket_mt6_v1,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
352		.matchsize	= sizeof(struct xt_socket_mtinfo1),
353		.hooks		= (1 << NF_INET_PRE_ROUTING) |
354				  (1 << NF_INET_LOCAL_IN),
355		.me		= THIS_MODULE,
356	},
357#endif
358};
359
360static int __init socket_mt_init(void)
361{
362	nf_defrag_ipv4_enable();
363#ifdef XT_SOCKET_HAVE_IPV6
364	nf_defrag_ipv6_enable();
365#endif
366
367	return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
368}
369
370static void __exit socket_mt_exit(void)
371{
372	xt_unregister_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
373}
374
375module_init(socket_mt_init);
376module_exit(socket_mt_exit);
377
378MODULE_LICENSE("GPL");
379MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
380MODULE_DESCRIPTION("x_tables socket match module");
381MODULE_ALIAS("ipt_socket");
382MODULE_ALIAS("ip6t_socket");