Commit | Line | Data |
---|---|---|
64eb12f9 JE |
1 | /* |
2 | * xt_conntrack - Netfilter module to match connection tracking | |
3 | * information. (Superset of Rusty's minimalistic state match.) | |
1da177e4 | 4 | * |
64eb12f9 JE |
5 | * (C) 2001 Marc Boucher (marc@mbsi.ca). |
6 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 | |
1da177e4 | 7 | * |
64eb12f9 JE |
8 | * This program is free software; you can redistribute it and/or modify |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
1da177e4 | 11 | */ |
8bee4bad | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/skbuff.h> | |
64eb12f9 | 15 | #include <net/ipv6.h> |
2e4e6a17 HW |
16 | #include <linux/netfilter/x_tables.h> |
17 | #include <linux/netfilter/xt_conntrack.h> | |
587aa641 | 18 | #include <net/netfilter/nf_conntrack.h> |
1da177e4 LT |
19 | |
20 | MODULE_LICENSE("GPL"); | |
21 | MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); | |
9e05ec4b | 22 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 23 | MODULE_DESCRIPTION("Xtables: connection tracking state match"); |
2e4e6a17 | 24 | MODULE_ALIAS("ipt_conntrack"); |
64eb12f9 | 25 | MODULE_ALIAS("ip6t_conntrack"); |
1da177e4 | 26 | |
64eb12f9 JE |
27 | static bool |
28 | conntrack_addrcmp(const union nf_inet_addr *kaddr, | |
29 | const union nf_inet_addr *uaddr, | |
30 | const union nf_inet_addr *umask, unsigned int l3proto) | |
31 | { | |
ee999d8b | 32 | if (l3proto == NFPROTO_IPV4) |
6556874d | 33 | return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0; |
ee999d8b | 34 | else if (l3proto == NFPROTO_IPV6) |
64eb12f9 JE |
35 | return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6, |
36 | &uaddr->in6) == 0; | |
37 | else | |
38 | return false; | |
39 | } | |
40 | ||
41 | static inline bool | |
42 | conntrack_mt_origsrc(const struct nf_conn *ct, | |
d6d3f08b | 43 | const struct xt_conntrack_mtinfo2 *info, |
76108cea | 44 | u_int8_t family) |
64eb12f9 JE |
45 | { |
46 | return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3, | |
47 | &info->origsrc_addr, &info->origsrc_mask, family); | |
48 | } | |
49 | ||
50 | static inline bool | |
51 | conntrack_mt_origdst(const struct nf_conn *ct, | |
d6d3f08b | 52 | const struct xt_conntrack_mtinfo2 *info, |
76108cea | 53 | u_int8_t family) |
64eb12f9 JE |
54 | { |
55 | return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3, | |
56 | &info->origdst_addr, &info->origdst_mask, family); | |
57 | } | |
58 | ||
59 | static inline bool | |
60 | conntrack_mt_replsrc(const struct nf_conn *ct, | |
d6d3f08b | 61 | const struct xt_conntrack_mtinfo2 *info, |
76108cea | 62 | u_int8_t family) |
64eb12f9 JE |
63 | { |
64 | return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3, | |
65 | &info->replsrc_addr, &info->replsrc_mask, family); | |
66 | } | |
67 | ||
68 | static inline bool | |
69 | conntrack_mt_repldst(const struct nf_conn *ct, | |
d6d3f08b | 70 | const struct xt_conntrack_mtinfo2 *info, |
76108cea | 71 | u_int8_t family) |
64eb12f9 JE |
72 | { |
73 | return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3, | |
74 | &info->repldst_addr, &info->repldst_mask, family); | |
75 | } | |
76 | ||
b4164998 | 77 | static inline bool |
d6d3f08b | 78 | ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info, |
b4164998 JE |
79 | const struct nf_conn *ct) |
80 | { | |
81 | const struct nf_conntrack_tuple *tuple; | |
82 | ||
83 | tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; | |
84 | if ((info->match_flags & XT_CONNTRACK_PROTO) && | |
5e8fbe2a | 85 | (nf_ct_protonum(ct) == info->l4proto) ^ |
b4164998 JE |
86 | !(info->invert_flags & XT_CONNTRACK_PROTO)) |
87 | return false; | |
88 | ||
89 | /* Shortcut to match all recognized protocols by using ->src.all. */ | |
90 | if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) && | |
91 | (tuple->src.u.all == info->origsrc_port) ^ | |
92 | !(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT)) | |
93 | return false; | |
94 | ||
95 | if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) && | |
96 | (tuple->dst.u.all == info->origdst_port) ^ | |
97 | !(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT)) | |
98 | return false; | |
99 | ||
100 | tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple; | |
101 | ||
102 | if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) && | |
103 | (tuple->src.u.all == info->replsrc_port) ^ | |
104 | !(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT)) | |
105 | return false; | |
106 | ||
107 | if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) && | |
108 | (tuple->dst.u.all == info->repldst_port) ^ | |
109 | !(info->invert_flags & XT_CONNTRACK_REPLDST_PORT)) | |
110 | return false; | |
111 | ||
112 | return true; | |
113 | } | |
114 | ||
b017900a PM |
115 | static inline bool |
116 | port_match(u16 min, u16 max, u16 port, bool invert) | |
117 | { | |
118 | return (port >= min && port <= max) ^ invert; | |
119 | } | |
120 | ||
121 | static inline bool | |
122 | ct_proto_port_check_v3(const struct xt_conntrack_mtinfo3 *info, | |
123 | const struct nf_conn *ct) | |
124 | { | |
125 | const struct nf_conntrack_tuple *tuple; | |
126 | ||
127 | tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; | |
128 | if ((info->match_flags & XT_CONNTRACK_PROTO) && | |
129 | (nf_ct_protonum(ct) == info->l4proto) ^ | |
130 | !(info->invert_flags & XT_CONNTRACK_PROTO)) | |
131 | return false; | |
132 | ||
133 | /* Shortcut to match all recognized protocols by using ->src.all. */ | |
134 | if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) && | |
135 | !port_match(info->origsrc_port, info->origsrc_port_high, | |
136 | ntohs(tuple->src.u.all), | |
137 | info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT)) | |
138 | return false; | |
139 | ||
140 | if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) && | |
141 | !port_match(info->origdst_port, info->origdst_port_high, | |
142 | ntohs(tuple->dst.u.all), | |
143 | info->invert_flags & XT_CONNTRACK_ORIGDST_PORT)) | |
144 | return false; | |
145 | ||
146 | tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple; | |
147 | ||
148 | if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) && | |
149 | !port_match(info->replsrc_port, info->replsrc_port_high, | |
150 | ntohs(tuple->src.u.all), | |
151 | info->invert_flags & XT_CONNTRACK_REPLSRC_PORT)) | |
152 | return false; | |
153 | ||
154 | if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) && | |
155 | !port_match(info->repldst_port, info->repldst_port_high, | |
156 | ntohs(tuple->dst.u.all), | |
157 | info->invert_flags & XT_CONNTRACK_REPLDST_PORT)) | |
158 | return false; | |
159 | ||
160 | return true; | |
161 | } | |
162 | ||
64eb12f9 | 163 | static bool |
62fc8051 | 164 | conntrack_mt(const struct sk_buff *skb, struct xt_action_param *par, |
3a042929 | 165 | u16 state_mask, u16 status_mask) |
64eb12f9 | 166 | { |
d6d3f08b | 167 | const struct xt_conntrack_mtinfo2 *info = par->matchinfo; |
64eb12f9 JE |
168 | enum ip_conntrack_info ctinfo; |
169 | const struct nf_conn *ct; | |
170 | unsigned int statebit; | |
171 | ||
172 | ct = nf_ct_get(skb, &ctinfo); | |
173 | ||
5bfddbd4 ED |
174 | if (ct) { |
175 | if (nf_ct_is_untracked(ct)) | |
176 | statebit = XT_CONNTRACK_STATE_UNTRACKED; | |
177 | else | |
178 | statebit = XT_CONNTRACK_STATE_BIT(ctinfo); | |
179 | } else | |
64eb12f9 JE |
180 | statebit = XT_CONNTRACK_STATE_INVALID; |
181 | ||
182 | if (info->match_flags & XT_CONNTRACK_STATE) { | |
183 | if (ct != NULL) { | |
184 | if (test_bit(IPS_SRC_NAT_BIT, &ct->status)) | |
185 | statebit |= XT_CONNTRACK_STATE_SNAT; | |
186 | if (test_bit(IPS_DST_NAT_BIT, &ct->status)) | |
187 | statebit |= XT_CONNTRACK_STATE_DNAT; | |
188 | } | |
3a042929 | 189 | if (!!(state_mask & statebit) ^ |
64eb12f9 JE |
190 | !(info->invert_flags & XT_CONNTRACK_STATE)) |
191 | return false; | |
192 | } | |
193 | ||
194 | if (ct == NULL) | |
195 | return info->match_flags & XT_CONNTRACK_STATE; | |
b4164998 JE |
196 | if ((info->match_flags & XT_CONNTRACK_DIRECTION) && |
197 | (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^ | |
96120d86 | 198 | !(info->invert_flags & XT_CONNTRACK_DIRECTION)) |
64eb12f9 JE |
199 | return false; |
200 | ||
201 | if (info->match_flags & XT_CONNTRACK_ORIGSRC) | |
92f3b2b1 | 202 | if (conntrack_mt_origsrc(ct, info, par->family) ^ |
64eb12f9 JE |
203 | !(info->invert_flags & XT_CONNTRACK_ORIGSRC)) |
204 | return false; | |
205 | ||
206 | if (info->match_flags & XT_CONNTRACK_ORIGDST) | |
92f3b2b1 | 207 | if (conntrack_mt_origdst(ct, info, par->family) ^ |
64eb12f9 JE |
208 | !(info->invert_flags & XT_CONNTRACK_ORIGDST)) |
209 | return false; | |
210 | ||
211 | if (info->match_flags & XT_CONNTRACK_REPLSRC) | |
92f3b2b1 | 212 | if (conntrack_mt_replsrc(ct, info, par->family) ^ |
64eb12f9 JE |
213 | !(info->invert_flags & XT_CONNTRACK_REPLSRC)) |
214 | return false; | |
215 | ||
216 | if (info->match_flags & XT_CONNTRACK_REPLDST) | |
92f3b2b1 | 217 | if (conntrack_mt_repldst(ct, info, par->family) ^ |
64eb12f9 JE |
218 | !(info->invert_flags & XT_CONNTRACK_REPLDST)) |
219 | return false; | |
220 | ||
b017900a PM |
221 | if (par->match->revision != 3) { |
222 | if (!ct_proto_port_check(info, ct)) | |
223 | return false; | |
224 | } else { | |
225 | if (!ct_proto_port_check_v3(par->matchinfo, ct)) | |
226 | return false; | |
227 | } | |
b4164998 | 228 | |
64eb12f9 | 229 | if ((info->match_flags & XT_CONNTRACK_STATUS) && |
3a042929 | 230 | (!!(status_mask & ct->status) ^ |
64eb12f9 JE |
231 | !(info->invert_flags & XT_CONNTRACK_STATUS))) |
232 | return false; | |
233 | ||
234 | if (info->match_flags & XT_CONNTRACK_EXPIRES) { | |
235 | unsigned long expires = 0; | |
236 | ||
237 | if (timer_pending(&ct->timeout)) | |
238 | expires = (ct->timeout.expires - jiffies) / HZ; | |
239 | if ((expires >= info->expires_min && | |
240 | expires <= info->expires_max) ^ | |
241 | !(info->invert_flags & XT_CONNTRACK_EXPIRES)) | |
242 | return false; | |
243 | } | |
244 | return true; | |
245 | } | |
246 | ||
d6d3f08b | 247 | static bool |
62fc8051 | 248 | conntrack_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
d6d3f08b | 249 | { |
3a042929 | 250 | const struct xt_conntrack_mtinfo1 *info = par->matchinfo; |
d6d3f08b | 251 | |
3a042929 FW |
252 | return conntrack_mt(skb, par, info->state_mask, info->status_mask); |
253 | } | |
254 | ||
255 | static bool | |
62fc8051 | 256 | conntrack_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
3a042929 FW |
257 | { |
258 | const struct xt_conntrack_mtinfo2 *info = par->matchinfo; | |
259 | ||
260 | return conntrack_mt(skb, par, info->state_mask, info->status_mask); | |
d6d3f08b JE |
261 | } |
262 | ||
b017900a PM |
263 | static bool |
264 | conntrack_mt_v3(const struct sk_buff *skb, struct xt_action_param *par) | |
265 | { | |
266 | const struct xt_conntrack_mtinfo3 *info = par->matchinfo; | |
267 | ||
268 | return conntrack_mt(skb, par, info->state_mask, info->status_mask); | |
269 | } | |
270 | ||
b0f38452 | 271 | static int conntrack_mt_check(const struct xt_mtchk_param *par) |
b9f78f9f | 272 | { |
4a5a5c73 JE |
273 | int ret; |
274 | ||
275 | ret = nf_ct_l3proto_try_module_get(par->family); | |
f95c74e3 | 276 | if (ret < 0) |
8bee4bad JE |
277 | pr_info("cannot load conntrack support for proto=%u\n", |
278 | par->family); | |
f95c74e3 | 279 | return ret; |
b9f78f9f PNA |
280 | } |
281 | ||
6be3d859 | 282 | static void conntrack_mt_destroy(const struct xt_mtdtor_param *par) |
b9f78f9f | 283 | { |
92f3b2b1 | 284 | nf_ct_l3proto_module_put(par->family); |
b9f78f9f PNA |
285 | } |
286 | ||
64eb12f9 | 287 | static struct xt_match conntrack_mt_reg[] __read_mostly = { |
64eb12f9 JE |
288 | { |
289 | .name = "conntrack", | |
290 | .revision = 1, | |
92f3b2b1 | 291 | .family = NFPROTO_UNSPEC, |
64eb12f9 | 292 | .matchsize = sizeof(struct xt_conntrack_mtinfo1), |
d6d3f08b | 293 | .match = conntrack_mt_v1, |
3a042929 FW |
294 | .checkentry = conntrack_mt_check, |
295 | .destroy = conntrack_mt_destroy, | |
d6d3f08b JE |
296 | .me = THIS_MODULE, |
297 | }, | |
298 | { | |
299 | .name = "conntrack", | |
300 | .revision = 2, | |
301 | .family = NFPROTO_UNSPEC, | |
302 | .matchsize = sizeof(struct xt_conntrack_mtinfo2), | |
3a042929 | 303 | .match = conntrack_mt_v2, |
64eb12f9 JE |
304 | .checkentry = conntrack_mt_check, |
305 | .destroy = conntrack_mt_destroy, | |
306 | .me = THIS_MODULE, | |
307 | }, | |
b017900a PM |
308 | { |
309 | .name = "conntrack", | |
310 | .revision = 3, | |
311 | .family = NFPROTO_UNSPEC, | |
312 | .matchsize = sizeof(struct xt_conntrack_mtinfo3), | |
313 | .match = conntrack_mt_v3, | |
314 | .checkentry = conntrack_mt_check, | |
315 | .destroy = conntrack_mt_destroy, | |
316 | .me = THIS_MODULE, | |
317 | }, | |
1da177e4 LT |
318 | }; |
319 | ||
d3c5ee6d | 320 | static int __init conntrack_mt_init(void) |
1da177e4 | 321 | { |
64eb12f9 JE |
322 | return xt_register_matches(conntrack_mt_reg, |
323 | ARRAY_SIZE(conntrack_mt_reg)); | |
1da177e4 LT |
324 | } |
325 | ||
d3c5ee6d | 326 | static void __exit conntrack_mt_exit(void) |
1da177e4 | 327 | { |
64eb12f9 | 328 | xt_unregister_matches(conntrack_mt_reg, ARRAY_SIZE(conntrack_mt_reg)); |
1da177e4 LT |
329 | } |
330 | ||
d3c5ee6d JE |
331 | module_init(conntrack_mt_init); |
332 | module_exit(conntrack_mt_exit); |