Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 13 | |
| 14 | #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/netfilter_ipv4/ip_conntrack.h> |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 16 | #include <linux/netfilter_ipv4/ip_conntrack_tuple.h> |
| 17 | #else |
| 18 | #include <net/netfilter/nf_conntrack.h> |
| 19 | #endif |
| 20 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 21 | #include <linux/netfilter/x_tables.h> |
| 22 | #include <linux/netfilter/xt_conntrack.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | |
| 24 | MODULE_LICENSE("GPL"); |
| 25 | MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); |
| 26 | MODULE_DESCRIPTION("iptables connection tracking match module"); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 27 | MODULE_ALIAS("ipt_conntrack"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 29 | #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE) |
| 30 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 37 | unsigned int protoff, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | int *hotdrop) |
| 39 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 40 | const struct xt_conntrack_info *sinfo = matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 50 | statebit = XT_CONNTRACK_STATE_UNTRACKED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | else if (ct) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 52 | statebit = XT_CONNTRACK_STATE_BIT(ctinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | else |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 54 | statebit = XT_CONNTRACK_STATE_INVALID; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 56 | if(sinfo->flags & XT_CONNTRACK_STATE) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | if (ct) { |
| 58 | if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip != |
| 59 | ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 60 | statebit |= XT_CONNTRACK_STATE_SNAT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip != |
| 63 | ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 64 | statebit |= XT_CONNTRACK_STATE_DNAT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | } |
| 66 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 67 | if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | return 0; |
| 69 | } |
| 70 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | return 0; |
| 74 | } |
| 75 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | return 0; |
| 79 | } |
| 80 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | return 0; |
| 84 | } |
| 85 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | return 0; |
| 89 | } |
| 90 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | return 0; |
| 94 | } |
| 95 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 96 | if(sinfo->flags & XT_CONNTRACK_STATUS) { |
| 97 | if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | return 0; |
| 99 | } |
| 100 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 101 | if(sinfo->flags & XT_CONNTRACK_EXPIRES) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 109 | if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | return 1; |
| 114 | } |
| 115 | |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 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, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 123 | unsigned int protoff, |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 124 | int *hotdrop) |
| 125 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 126 | const struct xt_conntrack_info *sinfo = matchinfo; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 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) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 136 | statebit = XT_CONNTRACK_STATE_UNTRACKED; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 137 | else if (ct) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 138 | statebit = XT_CONNTRACK_STATE_BIT(ctinfo); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 139 | else |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 140 | statebit = XT_CONNTRACK_STATE_INVALID; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 141 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 142 | if(sinfo->flags & XT_CONNTRACK_STATE) { |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 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) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 146 | statebit |= XT_CONNTRACK_STATE_SNAT; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 147 | |
| 148 | if(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip != |
| 149 | ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 150 | statebit |= XT_CONNTRACK_STATE_DNAT; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 151 | } |
| 152 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 153 | if (FWINV((statebit & sinfo->statemask) == 0, XT_CONNTRACK_STATE)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 154 | return 0; |
| 155 | } |
| 156 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 159 | return 0; |
| 160 | } |
| 161 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 164 | return 0; |
| 165 | } |
| 166 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 169 | return 0; |
| 170 | } |
| 171 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 174 | return 0; |
| 175 | } |
| 176 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 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)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 179 | return 0; |
| 180 | } |
| 181 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 182 | if(sinfo->flags & XT_CONNTRACK_STATUS) { |
| 183 | if (!ct || FWINV((ct->status & sinfo->statusmask) == 0, XT_CONNTRACK_STATUS)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 184 | return 0; |
| 185 | } |
| 186 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 187 | if(sinfo->flags & XT_CONNTRACK_EXPIRES) { |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 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 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 195 | if (FWINV(!(expires >= sinfo->expires_min && expires <= sinfo->expires_max), XT_CONNTRACK_EXPIRES)) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 196 | return 0; |
| 197 | } |
| 198 | |
| 199 | return 1; |
| 200 | } |
| 201 | |
| 202 | #endif /* CONFIG_NF_IP_CONNTRACK */ |
| 203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | static int check(const char *tablename, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 205 | const void *ip, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | void *matchinfo, |
| 207 | unsigned int matchsize, |
| 208 | unsigned int hook_mask) |
| 209 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 210 | if (matchsize != XT_ALIGN(sizeof(struct xt_conntrack_info))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | return 0; |
| 212 | |
| 213 | return 1; |
| 214 | } |
| 215 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 216 | static struct xt_match conntrack_match = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | .name = "conntrack", |
| 218 | .match = &match, |
| 219 | .checkentry = &check, |
| 220 | .me = THIS_MODULE, |
| 221 | }; |
| 222 | |
| 223 | static int __init init(void) |
| 224 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 225 | int ret; |
| 226 | need_conntrack(); |
| 227 | ret = xt_register_match(AF_INET, &conntrack_match); |
| 228 | |
| 229 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | } |
| 231 | |
| 232 | static void __exit fini(void) |
| 233 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame^] | 234 | xt_unregister_match(AF_INET, &conntrack_match); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | } |
| 236 | |
| 237 | module_init(init); |
| 238 | module_exit(fini); |