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 |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 23 | match(const struct sk_buff *skb, |
| 24 | const struct net_device *in, |
| 25 | const struct net_device *out, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 26 | const struct xt_match *match, |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 27 | const void *matchinfo, |
| 28 | int offset, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 29 | unsigned int protoff, |
Jan Engelhardt | cff533a | 2007-07-07 22:15:12 -0700 | [diff] [blame] | 30 | bool *hotdrop) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 31 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 32 | const struct xt_conntrack_info *sinfo = matchinfo; |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame^] | 33 | const struct nf_conn *ct; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 34 | enum ip_conntrack_info ctinfo; |
| 35 | unsigned int statebit; |
| 36 | |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame^] | 37 | ct = nf_ct_get(skb, &ctinfo); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 38 | |
| 39 | #define FWINV(bool,invflg) ((bool) ^ !!(sinfo->invflags & invflg)) |
| 40 | |
| 41 | if (ct == &nf_conntrack_untracked) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 42 | statebit = XT_CONNTRACK_STATE_UNTRACKED; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 43 | else if (ct) |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 44 | statebit = XT_CONNTRACK_STATE_BIT(ctinfo); |
| 45 | else |
| 46 | statebit = XT_CONNTRACK_STATE_INVALID; |
| 47 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 48 | if (sinfo->flags & XT_CONNTRACK_STATE) { |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 49 | if (ct) { |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 50 | if (test_bit(IPS_SRC_NAT_BIT, &ct->status)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 51 | statebit |= XT_CONNTRACK_STATE_SNAT; |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 52 | if (test_bit(IPS_DST_NAT_BIT, &ct->status)) |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 53 | statebit |= XT_CONNTRACK_STATE_DNAT; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 54 | } |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 55 | if (FWINV((statebit & sinfo->statemask) == 0, |
| 56 | XT_CONNTRACK_STATE)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 57 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 58 | } |
| 59 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 60 | if (ct == NULL) { |
| 61 | if (sinfo->flags & ~XT_CONNTRACK_STATE) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 62 | return false; |
| 63 | return true; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 64 | } |
| 65 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 66 | if (sinfo->flags & XT_CONNTRACK_PROTO && |
| 67 | FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 68 | sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 69 | XT_CONNTRACK_PROTO)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 70 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 71 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 72 | if (sinfo->flags & XT_CONNTRACK_ORIGSRC && |
| 73 | FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 74 | sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 75 | sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, |
| 76 | XT_CONNTRACK_ORIGSRC)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 77 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 78 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 79 | if (sinfo->flags & XT_CONNTRACK_ORIGDST && |
| 80 | FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 81 | sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 82 | sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, |
| 83 | XT_CONNTRACK_ORIGDST)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 84 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 85 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 86 | if (sinfo->flags & XT_CONNTRACK_REPLSRC && |
| 87 | FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 88 | sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 89 | sinfo->tuple[IP_CT_DIR_REPLY].src.ip, |
| 90 | XT_CONNTRACK_REPLSRC)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 91 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 92 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 93 | if (sinfo->flags & XT_CONNTRACK_REPLDST && |
| 94 | FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip & |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 95 | sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 96 | sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, |
| 97 | XT_CONNTRACK_REPLDST)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 98 | return false; |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 99 | |
| 100 | if (sinfo->flags & XT_CONNTRACK_STATUS && |
| 101 | FWINV((ct->status & sinfo->statusmask) == 0, |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 102 | XT_CONNTRACK_STATUS)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 103 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 104 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 105 | if(sinfo->flags & XT_CONNTRACK_EXPIRES) { |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 106 | unsigned long expires = timer_pending(&ct->timeout) ? |
| 107 | (ct->timeout.expires - jiffies)/HZ : 0; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 108 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 109 | if (FWINV(!(expires >= sinfo->expires_min && |
| 110 | expires <= sinfo->expires_max), |
| 111 | XT_CONNTRACK_EXPIRES)) |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 112 | return false; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 113 | } |
Jan Engelhardt | 1d93a9c | 2007-07-07 22:15:35 -0700 | [diff] [blame] | 114 | return true; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 115 | } |
| 116 | |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 117 | static bool |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 118 | checkentry(const char *tablename, |
| 119 | const void *ip, |
| 120 | const struct xt_match *match, |
| 121 | void *matchinfo, |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 122 | unsigned int hook_mask) |
| 123 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 124 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 125 | printk(KERN_WARNING "can't load conntrack support for " |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 126 | "proto=%d\n", match->family); |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 127 | return false; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 128 | } |
Jan Engelhardt | ccb79bd | 2007-07-07 22:16:00 -0700 | [diff] [blame] | 129 | return true; |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 130 | } |
| 131 | |
Patrick McHardy | 50b9f1d | 2006-09-20 11:58:17 -0700 | [diff] [blame] | 132 | static void destroy(const struct xt_match *match, void *matchinfo) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 133 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 134 | nf_ct_l3proto_module_put(match->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 135 | } |
| 136 | |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 137 | #ifdef CONFIG_COMPAT |
| 138 | struct compat_xt_conntrack_info |
| 139 | { |
| 140 | compat_uint_t statemask; |
| 141 | compat_uint_t statusmask; |
| 142 | struct ip_conntrack_old_tuple tuple[IP_CT_DIR_MAX]; |
| 143 | struct in_addr sipmsk[IP_CT_DIR_MAX]; |
| 144 | struct in_addr dipmsk[IP_CT_DIR_MAX]; |
| 145 | compat_ulong_t expires_min; |
| 146 | compat_ulong_t expires_max; |
| 147 | u_int8_t flags; |
| 148 | u_int8_t invflags; |
| 149 | }; |
| 150 | |
| 151 | static void compat_from_user(void *dst, void *src) |
| 152 | { |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame^] | 153 | const struct compat_xt_conntrack_info *cm = src; |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 154 | struct xt_conntrack_info m = { |
| 155 | .statemask = cm->statemask, |
| 156 | .statusmask = cm->statusmask, |
| 157 | .expires_min = cm->expires_min, |
| 158 | .expires_max = cm->expires_max, |
| 159 | .flags = cm->flags, |
| 160 | .invflags = cm->invflags, |
| 161 | }; |
| 162 | memcpy(m.tuple, cm->tuple, sizeof(m.tuple)); |
| 163 | memcpy(m.sipmsk, cm->sipmsk, sizeof(m.sipmsk)); |
| 164 | memcpy(m.dipmsk, cm->dipmsk, sizeof(m.dipmsk)); |
| 165 | memcpy(dst, &m, sizeof(m)); |
| 166 | } |
| 167 | |
| 168 | static int compat_to_user(void __user *dst, void *src) |
| 169 | { |
Jan Engelhardt | a47362a | 2007-07-07 22:16:55 -0700 | [diff] [blame^] | 170 | const struct xt_conntrack_info *m = src; |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 171 | struct compat_xt_conntrack_info cm = { |
| 172 | .statemask = m->statemask, |
| 173 | .statusmask = m->statusmask, |
| 174 | .expires_min = m->expires_min, |
| 175 | .expires_max = m->expires_max, |
| 176 | .flags = m->flags, |
| 177 | .invflags = m->invflags, |
| 178 | }; |
| 179 | memcpy(cm.tuple, m->tuple, sizeof(cm.tuple)); |
| 180 | memcpy(cm.sipmsk, m->sipmsk, sizeof(cm.sipmsk)); |
| 181 | memcpy(cm.dipmsk, m->dipmsk, sizeof(cm.dipmsk)); |
| 182 | return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; |
| 183 | } |
| 184 | #endif |
| 185 | |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 186 | static struct xt_match conntrack_match = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | .name = "conntrack", |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 188 | .match = match, |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 189 | .checkentry = checkentry, |
| 190 | .destroy = destroy, |
Patrick McHardy | 5d04bff | 2006-03-20 18:01:58 -0800 | [diff] [blame] | 191 | .matchsize = sizeof(struct xt_conntrack_info), |
Patrick McHardy | da0dd23 | 2007-05-10 14:17:58 -0700 | [diff] [blame] | 192 | #ifdef CONFIG_COMPAT |
| 193 | .compatsize = sizeof(struct compat_xt_conntrack_info), |
| 194 | .compat_from_user = compat_from_user, |
| 195 | .compat_to_user = compat_to_user, |
| 196 | #endif |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 197 | .family = AF_INET, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | .me = THIS_MODULE, |
| 199 | }; |
| 200 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 201 | static int __init xt_conntrack_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 203 | return xt_register_match(&conntrack_match); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | } |
| 205 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 206 | static void __exit xt_conntrack_fini(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
Pablo Neira Ayuso | a45049c | 2006-03-22 13:55:40 -0800 | [diff] [blame] | 208 | xt_unregister_match(&conntrack_match); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | } |
| 210 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 211 | module_init(xt_conntrack_init); |
| 212 | module_exit(xt_conntrack_fini); |