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> |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 13 | #include <linux/netfilter/x_tables.h> |
| 14 | #include <linux/netfilter/xt_conntrack.h> |
Patrick McHardy | 587aa64 | 2007-03-14 16:37:25 -0700 | [diff] [blame] | 15 | #include <net/netfilter/nf_conntrack.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | |
| 17 | MODULE_LICENSE("GPL"); |
| 18 | MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); |
| 19 | MODULE_DESCRIPTION("iptables connection tracking match module"); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 20 | MODULE_ALIAS("ipt_conntrack"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 22 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 23 | conntrack_mt(const struct sk_buff *skb, const struct net_device *in, |
| 24 | const struct net_device *out, const struct xt_match *match, |
| 25 | const void *matchinfo, int offset, unsigned int protoff, |
| 26 | bool *hotdrop) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 27 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 28 | const struct xt_conntrack_info *sinfo = matchinfo; |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 29 | const struct nf_conn *ct; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 30 | enum ip_conntrack_info ctinfo; |
| 31 | unsigned int statebit; |
| 32 | |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 33 | ct = nf_ct_get(skb, &ctinfo); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 34 | |
Jan Engelhardt | e79ec50 | 2007-12-17 22:44:06 -0800 | [diff] [blame^] | 35 | #define FWINV(bool, invflg) ((bool) ^ !!(sinfo->invflags & (invflg))) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 36 | |
| 37 | if (ct == &nf_conntrack_untracked) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 38 | statebit = XT_CONNTRACK_STATE_UNTRACKED; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 39 | else if (ct) |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 40 | statebit = XT_CONNTRACK_STATE_BIT(ctinfo); |
| 41 | else |
| 42 | statebit = XT_CONNTRACK_STATE_INVALID; |
| 43 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 44 | if (sinfo->flags & XT_CONNTRACK_STATE) { |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 45 | if (ct) { |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 46 | if (test_bit(IPS_SRC_NAT_BIT, &ct->status)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 47 | statebit |= XT_CONNTRACK_STATE_SNAT; |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 48 | if (test_bit(IPS_DST_NAT_BIT, &ct->status)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 49 | statebit |= XT_CONNTRACK_STATE_DNAT; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 50 | } |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 51 | if (FWINV((statebit & sinfo->statemask) == 0, |
| 52 | XT_CONNTRACK_STATE)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 53 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 54 | } |
| 55 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 56 | if (ct == NULL) { |
| 57 | if (sinfo->flags & ~XT_CONNTRACK_STATE) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 58 | return false; |
| 59 | return true; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 60 | } |
| 61 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 62 | if (sinfo->flags & XT_CONNTRACK_PROTO && |
| 63 | FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 64 | sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 65 | XT_CONNTRACK_PROTO)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 66 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 67 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 68 | if (sinfo->flags & XT_CONNTRACK_ORIGSRC && |
| 69 | FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 70 | sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 71 | sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, |
| 72 | XT_CONNTRACK_ORIGSRC)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 73 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 74 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 75 | if (sinfo->flags & XT_CONNTRACK_ORIGDST && |
| 76 | FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 77 | sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 78 | sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, |
| 79 | XT_CONNTRACK_ORIGDST)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 80 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 81 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 82 | if (sinfo->flags & XT_CONNTRACK_REPLSRC && |
| 83 | FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 84 | sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 85 | sinfo->tuple[IP_CT_DIR_REPLY].src.ip, |
| 86 | XT_CONNTRACK_REPLSRC)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 87 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 88 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 89 | if (sinfo->flags & XT_CONNTRACK_REPLDST && |
| 90 | FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 91 | sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 92 | sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, |
| 93 | XT_CONNTRACK_REPLDST)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 94 | return false; |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 95 | |
| 96 | if (sinfo->flags & XT_CONNTRACK_STATUS && |
| 97 | FWINV((ct->status & sinfo->statusmask) == 0, |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 98 | XT_CONNTRACK_STATUS)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 99 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 100 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 101 | if(sinfo->flags & XT_CONNTRACK_EXPIRES) { |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 102 | unsigned long expires = timer_pending(&ct->timeout) ? |
| 103 | (ct->timeout.expires - jiffies)/HZ : 0; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 104 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 105 | if (FWINV(!(expires >= sinfo->expires_min && |
| 106 | expires <= sinfo->expires_max), |
| 107 | XT_CONNTRACK_EXPIRES)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 108 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 109 | } |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 110 | return true; |
Jan Engelhardt | e79ec50 | 2007-12-17 22:44:06 -0800 | [diff] [blame^] | 111 | #undef FWINV |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 112 | } |
| 113 | |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 114 | static bool |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 115 | conntrack_mt_check(const char *tablename, const void *ip, |
| 116 | const struct xt_match *match, void *matchinfo, |
| 117 | unsigned int hook_mask) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 118 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 119 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 120 | printk(KERN_WARNING "can't load conntrack support for " |
Jan Engelhardt | df54aae | 2007-12-17 22:43:15 -0800 | [diff] [blame] | 121 | "proto=%u\n", match->family); |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 122 | return false; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 123 | } |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 124 | return true; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 125 | } |
| 126 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 127 | static void |
| 128 | conntrack_mt_destroy(const struct xt_match *match, void *matchinfo) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 129 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 130 | nf_ct_l3proto_module_put(match->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 131 | } |
| 132 | |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 133 | #ifdef CONFIG_COMPAT |
| 134 | struct compat_xt_conntrack_info |
| 135 | { |
| 136 | compat_uint_t statemask; |
| 137 | compat_uint_t statusmask; |
| 138 | struct ip_conntrack_old_tuple tuple[IP_CT_DIR_MAX]; |
| 139 | struct in_addr sipmsk[IP_CT_DIR_MAX]; |
| 140 | struct in_addr dipmsk[IP_CT_DIR_MAX]; |
| 141 | compat_ulong_t expires_min; |
| 142 | compat_ulong_t expires_max; |
| 143 | u_int8_t flags; |
| 144 | u_int8_t invflags; |
| 145 | }; |
| 146 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 147 | static void conntrack_mt_compat_from_user(void *dst, void *src) |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 148 | { |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 149 | const struct compat_xt_conntrack_info *cm = src; |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 150 | struct xt_conntrack_info m = { |
| 151 | .statemask = cm->statemask, |
| 152 | .statusmask = cm->statusmask, |
| 153 | .expires_min = cm->expires_min, |
| 154 | .expires_max = cm->expires_max, |
| 155 | .flags = cm->flags, |
| 156 | .invflags = cm->invflags, |
| 157 | }; |
| 158 | memcpy(m.tuple, cm->tuple, sizeof(m.tuple)); |
| 159 | memcpy(m.sipmsk, cm->sipmsk, sizeof(m.sipmsk)); |
| 160 | memcpy(m.dipmsk, cm->dipmsk, sizeof(m.dipmsk)); |
| 161 | memcpy(dst, &m, sizeof(m)); |
| 162 | } |
| 163 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 164 | static int conntrack_mt_compat_to_user(void __user *dst, void *src) |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 165 | { |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame] | 166 | const struct xt_conntrack_info *m = src; |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 167 | struct compat_xt_conntrack_info cm = { |
| 168 | .statemask = m->statemask, |
| 169 | .statusmask = m->statusmask, |
| 170 | .expires_min = m->expires_min, |
| 171 | .expires_max = m->expires_max, |
| 172 | .flags = m->flags, |
| 173 | .invflags = m->invflags, |
| 174 | }; |
| 175 | memcpy(cm.tuple, m->tuple, sizeof(cm.tuple)); |
| 176 | memcpy(cm.sipmsk, m->sipmsk, sizeof(cm.sipmsk)); |
| 177 | memcpy(cm.dipmsk, m->dipmsk, sizeof(cm.dipmsk)); |
| 178 | return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; |
| 179 | } |
| 180 | #endif |
| 181 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 182 | static struct xt_match conntrack_mt_reg __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | .name = "conntrack", |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 184 | .match = conntrack_mt, |
| 185 | .checkentry = conntrack_mt_check, |
| 186 | .destroy = conntrack_mt_destroy, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 187 | .matchsize = sizeof(struct xt_conntrack_info), |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 188 | #ifdef CONFIG_COMPAT |
| 189 | .compatsize = sizeof(struct compat_xt_conntrack_info), |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 190 | .compat_from_user = conntrack_mt_compat_from_user, |
| 191 | .compat_to_user = conntrack_mt_compat_to_user, |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 192 | #endif |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 193 | .family = AF_INET, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | .me = THIS_MODULE, |
| 195 | }; |
| 196 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 197 | static int __init conntrack_mt_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 199 | return xt_register_match(&conntrack_mt_reg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | } |
| 201 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 202 | static void __exit conntrack_mt_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | { |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 204 | xt_unregister_match(&conntrack_mt_reg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | } |
| 206 | |
Jan Engelhardt | d3c5ee6 | 2007-12-04 23:24:03 -0800 | [diff] [blame] | 207 | module_init(conntrack_mt_init); |
| 208 | module_exit(conntrack_mt_exit); |