vlan: Move vlan_set_encap_proto() to vlan header file
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / xt_socket.c
CommitLineData
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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 */
ff67e4e4 12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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>
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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>
b64c9256 28#include <net/netfilter/ipv6/nf_defrag_ipv6.h>
f6318e55 29#endif
136cdc71 30
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31#include <linux/netfilter/xt_socket.h>
32
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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
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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
136cdc71 47static int
b64c9256 48extract_icmp4_fields(const struct sk_buff *skb,
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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
136cdc71 104static bool
62fc8051 105socket_match(const struct sk_buff *skb, struct xt_action_param *par,
a31e1ffd 106 const struct xt_socket_mtinfo1 *info)
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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) {
b64c9256 132 if (extract_icmp4_fields(skb, &protocol, &saddr, &daddr,
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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);
5bfddbd4 144 if (ct && !nf_ct_is_untracked(ct) &&
136cdc71 145 ((iph->protocol != IPPROTO_ICMP &&
fb048833 146 ctinfo == IP_CT_ESTABLISHED_REPLY) ||
136cdc71 147 (iph->protocol == IPPROTO_ICMP &&
fb048833 148 ctinfo == IP_CT_RELATED_REPLY)) &&
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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,
106e4c26 159 saddr, daddr, sport, dport, par->in, NFT_LOOKUP_ANY);
136cdc71 160 if (sk != NULL) {
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161 bool wildcard;
162 bool transparent = true;
163
164 /* Ignore sockets listening on INADDR_ANY */
165 wildcard = (sk->sk_state != TCP_TIME_WAIT &&
c720c7e8 166 inet_sk(sk)->inet_rcv_saddr == 0);
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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));
136cdc71 175
d503b30b 176 xt_socket_put_sk(sk);
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177
178 if (wildcard || !transparent)
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179 sk = NULL;
180 }
181
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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);
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186
187 return (sk != NULL);
188}
189
a31e1ffd 190static bool
b64c9256 191socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
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192{
193 return socket_match(skb, par, NULL);
194}
195
196static bool
b64c9256 197socket_mt4_v1(const struct sk_buff *skb, struct xt_action_param *par)
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198{
199 return socket_match(skb, par, par->matchinfo);
200}
201
f6318e55 202#ifdef XT_SOCKET_HAVE_IPV6
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203
204static int
205extract_icmp6_fields(const struct sk_buff *skb,
206 unsigned int outside_hdrlen,
089282fb 207 int *protocol,
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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;
089282fb 264 int thoff, tproto;
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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
d503b30b 310 xt_socket_put_sk(sk);
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311
312 if (wildcard || !transparent)
313 sk = NULL;
314 }
315
089282fb 316 pr_debug("proto %hhd %pI6:%hu -> %pI6:%hu "
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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
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326static struct xt_match socket_mt_reg[] __read_mostly = {
327 {
328 .name = "socket",
329 .revision = 0,
330 .family = NFPROTO_IPV4,
b64c9256 331 .match = socket_mt4_v0,
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332 .hooks = (1 << NF_INET_PRE_ROUTING) |
333 (1 << NF_INET_LOCAL_IN),
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334 .me = THIS_MODULE,
335 },
336 {
337 .name = "socket",
338 .revision = 1,
339 .family = NFPROTO_IPV4,
b64c9256 340 .match = socket_mt4_v1,
a31e1ffd 341 .matchsize = sizeof(struct xt_socket_mtinfo1),
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342 .hooks = (1 << NF_INET_PRE_ROUTING) |
343 (1 << NF_INET_LOCAL_IN),
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344 .me = THIS_MODULE,
345 },
f6318e55 346#ifdef XT_SOCKET_HAVE_IPV6
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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
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358};
359
360static int __init socket_mt_init(void)
361{
362 nf_defrag_ipv4_enable();
f6318e55 363#ifdef XT_SOCKET_HAVE_IPV6
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364 nf_defrag_ipv6_enable();
365#endif
366
a31e1ffd 367 return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
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368}
369
370static void __exit socket_mt_exit(void)
371{
a31e1ffd 372 xt_unregister_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
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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");
b64c9256 382MODULE_ALIAS("ip6t_socket");