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IB/mlx4: fix sprintf format warning
[linux/fpc-iii.git] / net / netfilter / xt_socket.c
blobe75ef39669c5a9a5b72c9a1cec8b72020600eae1
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/ipv4/nf_defrag_ipv4.h>
23
24 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
25 #include <linux/netfilter_ipv6/ip6_tables.h>
26 #include <net/inet6_hashtables.h>
27 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
28 #endif
29
30 #include <net/netfilter/nf_socket.h>
31 #include <linux/netfilter/xt_socket.h>
32
33 /* "socket" match based redirection (no specific rule)
34 * ===================================================
35 *
36 * There are connections with dynamic endpoints (e.g. FTP data
37 * connection) that the user is unable to add explicit rules
38 * for. These are taken care of by a generic "socket" rule. It is
39 * assumed that the proxy application is trusted to open such
40 * connections without explicit iptables rule (except of course the
41 * generic 'socket' rule). In this case the following sockets are
42 * matched in preference order:
43 *
44 * - match: if there's a fully established connection matching the
45 * _packet_ tuple
46 *
47 * - match: if there's a non-zero bound listener (possibly with a
48 * non-local address) We don't accept zero-bound listeners, since
49 * then local services could intercept traffic going through the
50 * box.
51 */
52 static bool
53 socket_match(const struct sk_buff *skb, struct xt_action_param *par,
54 const struct xt_socket_mtinfo1 *info)
55 {
56 struct sk_buff *pskb = (struct sk_buff *)skb;
57 struct sock *sk = skb->sk;
58
59 if (!sk)
60 sk = nf_sk_lookup_slow_v4(xt_net(par), skb, xt_in(par));
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 = nf_sk_is_transparent(sk);
77
78 if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
79 transparent)
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
92 static bool
93 socket_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
102 static bool
103 socket_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)
109 static bool
110 socket_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)
117 sk = nf_sk_lookup_slow_v6(xt_net(par), skb, xt_in(par));
118 if (sk) {
119 bool wildcard;
120 bool transparent = true;
121
122 /* Ignore sockets listening on INADDR_ANY
123 * unless XT_SOCKET_NOWILDCARD is set
124 */
125 wildcard = (!(info->flags & XT_SOCKET_NOWILDCARD) &&
126 sk_fullsock(sk) &&
127 ipv6_addr_any(&sk->sk_v6_rcv_saddr));
128
129 /* Ignore non-transparent sockets,
130 * if XT_SOCKET_TRANSPARENT is used
131 */
132 if (info->flags & XT_SOCKET_TRANSPARENT)
133 transparent = nf_sk_is_transparent(sk);
134
135 if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
136 transparent)
137 pskb->mark = sk->sk_mark;
138
139 if (sk != skb->sk)
140 sock_gen_put(sk);
141
142 if (wildcard || !transparent)
143 sk = NULL;
144 }
145
146 return sk != NULL;
147 }
148 #endif
149
150 static int socket_mt_enable_defrag(struct net *net, int family)
151 {
152 switch (family) {
153 case NFPROTO_IPV4:
154 return nf_defrag_ipv4_enable(net);
155 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
156 case NFPROTO_IPV6:
157 return nf_defrag_ipv6_enable(net);
158 #endif
159 }
160 WARN_ONCE(1, "Unknown family %d\n", family);
161 return 0;
162 }
163
164 static int socket_mt_v1_check(const struct xt_mtchk_param *par)
165 {
166 const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
167 int err;
168
169 err = socket_mt_enable_defrag(par->net, par->family);
170 if (err)
171 return err;
172
173 if (info->flags & ~XT_SOCKET_FLAGS_V1) {
174 pr_info("unknown flags 0x%x\n", info->flags & ~XT_SOCKET_FLAGS_V1);
175 return -EINVAL;
176 }
177 return 0;
178 }
179
180 static int socket_mt_v2_check(const struct xt_mtchk_param *par)
181 {
182 const struct xt_socket_mtinfo2 *info = (struct xt_socket_mtinfo2 *) par->matchinfo;
183 int err;
184
185 err = socket_mt_enable_defrag(par->net, par->family);
186 if (err)
187 return err;
188
189 if (info->flags & ~XT_SOCKET_FLAGS_V2) {
190 pr_info("unknown flags 0x%x\n", info->flags & ~XT_SOCKET_FLAGS_V2);
191 return -EINVAL;
192 }
193 return 0;
194 }
195
196 static int socket_mt_v3_check(const struct xt_mtchk_param *par)
197 {
198 const struct xt_socket_mtinfo3 *info =
199 (struct xt_socket_mtinfo3 *)par->matchinfo;
200 int err;
201
202 err = socket_mt_enable_defrag(par->net, par->family);
203 if (err)
204 return err;
205 if (info->flags & ~XT_SOCKET_FLAGS_V3) {
206 pr_info("unknown flags 0x%x\n",
207 info->flags & ~XT_SOCKET_FLAGS_V3);
208 return -EINVAL;
209 }
210 return 0;
211 }
212
213 static struct xt_match socket_mt_reg[] __read_mostly = {
214 {
215 .name = "socket",
216 .revision = 0,
217 .family = NFPROTO_IPV4,
218 .match = socket_mt4_v0,
219 .hooks = (1 << NF_INET_PRE_ROUTING) |
220 (1 << NF_INET_LOCAL_IN),
221 .me = THIS_MODULE,
222 },
223 {
224 .name = "socket",
225 .revision = 1,
226 .family = NFPROTO_IPV4,
227 .match = socket_mt4_v1_v2_v3,
228 .checkentry = socket_mt_v1_check,
229 .matchsize = sizeof(struct xt_socket_mtinfo1),
230 .hooks = (1 << NF_INET_PRE_ROUTING) |
231 (1 << NF_INET_LOCAL_IN),
232 .me = THIS_MODULE,
233 },
234 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
235 {
236 .name = "socket",
237 .revision = 1,
238 .family = NFPROTO_IPV6,
239 .match = socket_mt6_v1_v2_v3,
240 .checkentry = socket_mt_v1_check,
241 .matchsize = sizeof(struct xt_socket_mtinfo1),
242 .hooks = (1 << NF_INET_PRE_ROUTING) |
243 (1 << NF_INET_LOCAL_IN),
244 .me = THIS_MODULE,
245 },
246 #endif
247 {
248 .name = "socket",
249 .revision = 2,
250 .family = NFPROTO_IPV4,
251 .match = socket_mt4_v1_v2_v3,
252 .checkentry = socket_mt_v2_check,
253 .matchsize = sizeof(struct xt_socket_mtinfo1),
254 .hooks = (1 << NF_INET_PRE_ROUTING) |
255 (1 << NF_INET_LOCAL_IN),
256 .me = THIS_MODULE,
257 },
258 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
259 {
260 .name = "socket",
261 .revision = 2,
262 .family = NFPROTO_IPV6,
263 .match = socket_mt6_v1_v2_v3,
264 .checkentry = socket_mt_v2_check,
265 .matchsize = sizeof(struct xt_socket_mtinfo1),
266 .hooks = (1 << NF_INET_PRE_ROUTING) |
267 (1 << NF_INET_LOCAL_IN),
268 .me = THIS_MODULE,
269 },
270 #endif
271 {
272 .name = "socket",
273 .revision = 3,
274 .family = NFPROTO_IPV4,
275 .match = socket_mt4_v1_v2_v3,
276 .checkentry = socket_mt_v3_check,
277 .matchsize = sizeof(struct xt_socket_mtinfo1),
278 .hooks = (1 << NF_INET_PRE_ROUTING) |
279 (1 << NF_INET_LOCAL_IN),
280 .me = THIS_MODULE,
281 },
282 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
283 {
284 .name = "socket",
285 .revision = 3,
286 .family = NFPROTO_IPV6,
287 .match = socket_mt6_v1_v2_v3,
288 .checkentry = socket_mt_v3_check,
289 .matchsize = sizeof(struct xt_socket_mtinfo1),
290 .hooks = (1 << NF_INET_PRE_ROUTING) |
291 (1 << NF_INET_LOCAL_IN),
292 .me = THIS_MODULE,
293 },
294 #endif
295 };
296
297 static int __init socket_mt_init(void)
298 {
299 return xt_register_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
300 }
301
302 static void __exit socket_mt_exit(void)
303 {
304 xt_unregister_matches(socket_mt_reg, ARRAY_SIZE(socket_mt_reg));
305 }
306
307 module_init(socket_mt_init);
308 module_exit(socket_mt_exit);
309
310 MODULE_LICENSE("GPL");
311 MODULE_AUTHOR("Krisztian Kovacs, Balazs Scheidler");
312 MODULE_DESCRIPTION("x_tables socket match module");
313 MODULE_ALIAS("ipt_socket");
314 MODULE_ALIAS("ip6t_socket");
Linux with added FPC-III support