Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6
[deliverable/linux.git] / net / netfilter / xt_conntrack.c
1 /* Kernel module to match connection tracking information.
2 * Superset of Rusty's minimalistic state match.
3 *
4 * (C) 2001 Marc Boucher (marc@mbsi.ca).
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/module.h>
12 #include <linux/skbuff.h>
13
14 #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
15 #include <linux/netfilter_ipv4/ip_conntrack.h>
16 #include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
17 #else
18 #include <net/netfilter/nf_conntrack.h>
19 #endif
20
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter/xt_conntrack.h>
23
24 MODULE_LICENSE("GPL");
25 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
26 MODULE_DESCRIPTION("iptables connection tracking match module");
27 MODULE_ALIAS("ipt_conntrack");
28
29 #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
30
31 static int
32 match(const struct sk_buff *skb,
33 const struct net_device *in,
34 const struct net_device *out,
35 const void *matchinfo,
36 int offset,
37 unsigned int protoff,
38 int *hotdrop)
39 {
40 const struct xt_conntrack_info *sinfo = matchinfo;
41 struct ip_conntrack *ct;
42 enum ip_conntrack_info ctinfo;
43 unsigned int statebit;
44
45 ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
46
47 #define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
48
49 if (ct == &ip_conntrack_untracked)
50 statebit = XT_CONNTRACK_STATE_UNTRACKED;
51 else if (ct)
52 statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
53 else
54 statebit = XT_CONNTRACK_STATE_INVALID;
55
56 if(sinfo->flags & XT_CONNTRACK_STATE) {
57 if (ct) {
58 if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip !=
59 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip)
60 statebit |= XT_CONNTRACK_STATE_SNAT;
61
62 if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip !=
63 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip)
64 statebit |= XT_CONNTRACK_STATE_DNAT;
65 }
66
67 if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
68 return 0;
69 }
70
71 if(sinfo->flags & XT_CONNTRACK_PROTO) {
72 if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
73 return 0;
74 }
75
76 if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
77 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, XT_CONNTRACK_ORIGSRC))
78 return 0;
79 }
80
81 if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
82 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, XT_CONNTRACK_ORIGDST))
83 return 0;
84 }
85
86 if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
87 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, XT_CONNTRACK_REPLSRC))
88 return 0;
89 }
90
91 if(sinfo->flags & XT_CONNTRACK_REPLDST) {
92 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, XT_CONNTRACK_REPLDST))
93 return 0;
94 }
95
96 if(sinfo->flags & XT_CONNTRACK_STATUS) {
97 if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
98 return 0;
99 }
100
101 if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
102 unsigned long expires;
103
104 if(!ct)
105 return 0;
106
107 expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
108
109 if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES))
110 return 0;
111 }
112
113 return 1;
114 }
115
116 #else /* CONFIG_IP_NF_CONNTRACK */
117 static int
118 match(const struct sk_buff *skb,
119 const struct net_device *in,
120 const struct net_device *out,
121 const void *matchinfo,
122 int offset,
123 unsigned int protoff,
124 int *hotdrop)
125 {
126 const struct xt_conntrack_info *sinfo = matchinfo;
127 struct nf_conn *ct;
128 enum ip_conntrack_info ctinfo;
129 unsigned int statebit;
130
131 ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
132
133 #define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
134
135 if (ct == &nf_conntrack_untracked)
136 statebit = XT_CONNTRACK_STATE_UNTRACKED;
137 else if (ct)
138 statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
139 else
140 statebit = XT_CONNTRACK_STATE_INVALID;
141
142 if(sinfo->flags & XT_CONNTRACK_STATE) {
143 if (ct) {
144 if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip !=
145 ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip)
146 statebit |= XT_CONNTRACK_STATE_SNAT;
147
148 if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip !=
149 ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip)
150 statebit |= XT_CONNTRACK_STATE_DNAT;
151 }
152
153 if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE))
154 return 0;
155 }
156
157 if(sinfo->flags & XT_CONNTRACK_PROTO) {
158 if (!ct || FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, XT_CONNTRACK_PROTO))
159 return 0;
160 }
161
162 if(sinfo->flags & XT_CONNTRACK_ORIGSRC) {
163 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, XT_CONNTRACK_ORIGSRC))
164 return 0;
165 }
166
167 if(sinfo->flags & XT_CONNTRACK_ORIGDST) {
168 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, XT_CONNTRACK_ORIGDST))
169 return 0;
170 }
171
172 if(sinfo->flags & XT_CONNTRACK_REPLSRC) {
173 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip&sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].src.ip, XT_CONNTRACK_REPLSRC))
174 return 0;
175 }
176
177 if(sinfo->flags & XT_CONNTRACK_REPLDST) {
178 if (!ct || FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip&sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, XT_CONNTRACK_REPLDST))
179 return 0;
180 }
181
182 if(sinfo->flags & XT_CONNTRACK_STATUS) {
183 if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS))
184 return 0;
185 }
186
187 if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
188 unsigned long expires;
189
190 if(!ct)
191 return 0;
192
193 expires = timer_pending(&ct->timeout) ? (ct->timeout.expires - jiffies)/HZ : 0;
194
195 if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES))
196 return 0;
197 }
198
199 return 1;
200 }
201
202 #endif /* CONFIG_NF_IP_CONNTRACK */
203
204 static int check(const char *tablename,
205 const void *ip,
206 void *matchinfo,
207 unsigned int matchsize,
208 unsigned int hook_mask)
209 {
210 if (matchsize != XT_ALIGN(sizeof(struct xt_conntrack_info)))
211 return 0;
212
213 return 1;
214 }
215
216 static struct xt_match conntrack_match = {
217 .name = "conntrack",
218 .match = &match,
219 .checkentry = &check,
220 .me = THIS_MODULE,
221 };
222
223 static int __init init(void)
224 {
225 int ret;
226 need_conntrack();
227 ret = xt_register_match(AF_INET, &conntrack_match);
228
229 return ret;
230 }
231
232 static void __exit fini(void)
233 {
234 xt_unregister_match(AF_INET, &conntrack_match);
235 }
236
237 module_init(init);
238 module_exit(fini);
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