[PATCH] retries in ext4_prepare_write() violate ordering requirements
[usb.git] / net / netfilter / xt_conntrack.c
blob0ea501a2fda5b03458ef0bdc510e36ef7f28660a
1 /* Kernel module to match connection tracking information.
2 * Superset of Rusty's minimalistic state match.
4 * (C) 2001 Marc Boucher (marc@mbsi.ca).
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 */
11 #include <linux/module.h>
12 #include <linux/skbuff.h>
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
21 #include <linux/netfilter/x_tables.h>
22 #include <linux/netfilter/xt_conntrack.h>
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");
29 #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
31 static int
32 match(const struct sk_buff *skb,
33 const struct net_device *in,
34 const struct net_device *out,
35 const struct xt_match *match,
36 const void *matchinfo,
37 int offset,
38 unsigned int protoff,
39 int *hotdrop)
41 const struct xt_conntrack_info *sinfo = matchinfo;
42 struct ip_conntrack *ct;
43 enum ip_conntrack_info ctinfo;
44 unsigned int statebit;
46 ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo);
48 #define FWINV(bool, invflg) ((bool) ^ !!(sinfo->invflags & invflg))
50 if (ct == &ip_conntrack_untracked)
51 statebit = XT_CONNTRACK_STATE_UNTRACKED;
52 else if (ct)
53 statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
54 else
55 statebit = XT_CONNTRACK_STATE_INVALID;
57 if (sinfo->flags & XT_CONNTRACK_STATE) {
58 if (ct) {
59 if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
60 statebit |= XT_CONNTRACK_STATE_SNAT;
61 if (test_bit(IPS_DST_NAT_BIT, &ct->status))
62 statebit |= XT_CONNTRACK_STATE_DNAT;
64 if (FWINV((statebit & sinfo->statemask) == 0,
65 XT_CONNTRACK_STATE))
66 return 0;
69 if (ct == NULL) {
70 if (sinfo->flags & ~XT_CONNTRACK_STATE)
71 return 0;
72 return 1;
75 if (sinfo->flags & XT_CONNTRACK_PROTO &&
76 FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum !=
77 sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum,
78 XT_CONNTRACK_PROTO))
79 return 0;
81 if (sinfo->flags & XT_CONNTRACK_ORIGSRC &&
82 FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip &
83 sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
84 sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip,
85 XT_CONNTRACK_ORIGSRC))
86 return 0;
88 if (sinfo->flags & XT_CONNTRACK_ORIGDST &&
89 FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip &
90 sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
91 sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip,
92 XT_CONNTRACK_ORIGDST))
93 return 0;
95 if (sinfo->flags & XT_CONNTRACK_REPLSRC &&
96 FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip &
97 sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) !=
98 sinfo->tuple[IP_CT_DIR_REPLY].src.ip,
99 XT_CONNTRACK_REPLSRC))
100 return 0;
102 if (sinfo->flags & XT_CONNTRACK_REPLDST &&
103 FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip &
104 sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) !=
105 sinfo->tuple[IP_CT_DIR_REPLY].dst.ip,
106 XT_CONNTRACK_REPLDST))
107 return 0;
109 if (sinfo->flags & XT_CONNTRACK_STATUS &&
110 FWINV((ct->status & sinfo->statusmask) == 0,
111 XT_CONNTRACK_STATUS))
112 return 0;
114 if (sinfo->flags & XT_CONNTRACK_EXPIRES) {
115 unsigned long expires = timer_pending(&ct->timeout) ?
116 (ct->timeout.expires - jiffies)/HZ : 0;
118 if (FWINV(!(expires >= sinfo->expires_min &&
119 expires <= sinfo->expires_max),
120 XT_CONNTRACK_EXPIRES))
121 return 0;
123 return 1;
126 #else /* CONFIG_IP_NF_CONNTRACK */
127 static int
128 match(const struct sk_buff *skb,
129 const struct net_device *in,
130 const struct net_device *out,
131 const struct xt_match *match,
132 const void *matchinfo,
133 int offset,
134 unsigned int protoff,
135 int *hotdrop)
137 const struct xt_conntrack_info *sinfo = matchinfo;
138 struct nf_conn *ct;
139 enum ip_conntrack_info ctinfo;
140 unsigned int statebit;
142 ct = nf_ct_get((struct sk_buff *)skb, &ctinfo);
144 #define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg))
146 if (ct == &nf_conntrack_untracked)
147 statebit = XT_CONNTRACK_STATE_UNTRACKED;
148 else if (ct)
149 statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
150 else
151 statebit = XT_CONNTRACK_STATE_INVALID;
153 if (sinfo->flags & XT_CONNTRACK_STATE) {
154 if (ct) {
155 if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
156 statebit |= XT_CONNTRACK_STATE_SNAT;
157 if (test_bit(IPS_DST_NAT_BIT, &ct->status))
158 statebit |= XT_CONNTRACK_STATE_DNAT;
160 if (FWINV((statebit & sinfo->statemask) == 0,
161 XT_CONNTRACK_STATE))
162 return 0;
165 if (ct == NULL) {
166 if (sinfo->flags & ~XT_CONNTRACK_STATE)
167 return 0;
168 return 1;
171 if (sinfo->flags & XT_CONNTRACK_PROTO &&
172 FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum !=
173 sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum,
174 XT_CONNTRACK_PROTO))
175 return 0;
177 if (sinfo->flags & XT_CONNTRACK_ORIGSRC &&
178 FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip &
179 sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
180 sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip,
181 XT_CONNTRACK_ORIGSRC))
182 return 0;
184 if (sinfo->flags & XT_CONNTRACK_ORIGDST &&
185 FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip &
186 sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) !=
187 sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip,
188 XT_CONNTRACK_ORIGDST))
189 return 0;
191 if (sinfo->flags & XT_CONNTRACK_REPLSRC &&
192 FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip &
193 sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) !=
194 sinfo->tuple[IP_CT_DIR_REPLY].src.ip,
195 XT_CONNTRACK_REPLSRC))
196 return 0;
198 if (sinfo->flags & XT_CONNTRACK_REPLDST &&
199 FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip &
200 sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) !=
201 sinfo->tuple[IP_CT_DIR_REPLY].dst.ip,
202 XT_CONNTRACK_REPLDST))
203 return 0;
205 if (sinfo->flags & XT_CONNTRACK_STATUS &&
206 FWINV((ct->status & sinfo->statusmask) == 0,
207 XT_CONNTRACK_STATUS))
208 return 0;
210 if(sinfo->flags & XT_CONNTRACK_EXPIRES) {
211 unsigned long expires = timer_pending(&ct->timeout) ?
212 (ct->timeout.expires - jiffies)/HZ : 0;
214 if (FWINV(!(expires >= sinfo->expires_min &&
215 expires <= sinfo->expires_max),
216 XT_CONNTRACK_EXPIRES))
217 return 0;
219 return 1;
222 #endif /* CONFIG_NF_IP_CONNTRACK */
224 static int
225 checkentry(const char *tablename,
226 const void *ip,
227 const struct xt_match *match,
228 void *matchinfo,
229 unsigned int hook_mask)
231 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
232 if (nf_ct_l3proto_try_module_get(match->family) < 0) {
233 printk(KERN_WARNING "can't load nf_conntrack support for "
234 "proto=%d\n", match->family);
235 return 0;
237 #endif
238 return 1;
241 static void destroy(const struct xt_match *match, void *matchinfo)
243 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
244 nf_ct_l3proto_module_put(match->family);
245 #endif
248 static struct xt_match conntrack_match = {
249 .name = "conntrack",
250 .match = match,
251 .checkentry = checkentry,
252 .destroy = destroy,
253 .matchsize = sizeof(struct xt_conntrack_info),
254 .family = AF_INET,
255 .me = THIS_MODULE,
258 static int __init xt_conntrack_init(void)
260 need_conntrack();
261 return xt_register_match(&conntrack_match);
264 static void __exit xt_conntrack_fini(void)
266 xt_unregister_match(&conntrack_match);
269 module_init(xt_conntrack_init);
270 module_exit(xt_conntrack_fini);