Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* iptables module to match on related connections */ |
| 2 | /* |
| 3 | * (C) 2001 Martin Josefsson <gandalf@wlug.westbo.se> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * 19 Mar 2002 Harald Welte <laforge@gnumonks.org>: |
| 10 | * - Port to newnat infrastructure |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/netfilter.h> |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 16 | #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/netfilter_ipv4/ip_conntrack.h> |
| 18 | #include <linux/netfilter_ipv4/ip_conntrack_core.h> |
| 19 | #include <linux/netfilter_ipv4/ip_conntrack_helper.h> |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 20 | #else |
| 21 | #include <net/netfilter/nf_conntrack.h> |
| 22 | #include <net/netfilter/nf_conntrack_core.h> |
| 23 | #include <net/netfilter/nf_conntrack_helper.h> |
| 24 | #endif |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 25 | #include <linux/netfilter/x_tables.h> |
| 26 | #include <linux/netfilter/xt_helper.h> |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 27 | #include <net/netfilter/nf_conntrack_compat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
| 29 | MODULE_LICENSE("GPL"); |
| 30 | MODULE_AUTHOR("Martin Josefsson <gandalf@netfilter.org>"); |
| 31 | MODULE_DESCRIPTION("iptables helper match module"); |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 32 | MODULE_ALIAS("ipt_helper"); |
| 33 | MODULE_ALIAS("ip6t_helper"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
| 35 | #if 0 |
| 36 | #define DEBUGP printk |
| 37 | #else |
| 38 | #define DEBUGP(format, args...) |
| 39 | #endif |
| 40 | |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 41 | #if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | static int |
| 43 | match(const struct sk_buff *skb, |
| 44 | const struct net_device *in, |
| 45 | const struct net_device *out, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 46 | const struct xt_match *match, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | const void *matchinfo, |
| 48 | int offset, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 49 | unsigned int protoff, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | int *hotdrop) |
| 51 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 52 | const struct xt_helper_info *info = matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | struct ip_conntrack *ct; |
| 54 | enum ip_conntrack_info ctinfo; |
| 55 | int ret = info->invert; |
| 56 | |
| 57 | ct = ip_conntrack_get((struct sk_buff *)skb, &ctinfo); |
| 58 | if (!ct) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 59 | DEBUGP("xt_helper: Eek! invalid conntrack?\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | return ret; |
| 61 | } |
| 62 | |
| 63 | if (!ct->master) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 64 | DEBUGP("xt_helper: conntrack %p has no master\n", ct); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | return ret; |
| 66 | } |
| 67 | |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame] | 68 | read_lock_bh(&ip_conntrack_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | if (!ct->master->helper) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 70 | DEBUGP("xt_helper: master ct %p has no helper\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | exp->expectant); |
| 72 | goto out_unlock; |
| 73 | } |
| 74 | |
| 75 | DEBUGP("master's name = %s , info->name = %s\n", |
| 76 | ct->master->helper->name, info->name); |
| 77 | |
| 78 | if (info->name[0] == '\0') |
| 79 | ret ^= 1; |
| 80 | else |
| 81 | ret ^= !strncmp(ct->master->helper->name, info->name, |
| 82 | strlen(ct->master->helper->name)); |
| 83 | out_unlock: |
Patrick McHardy | e45b1be | 2005-06-21 14:01:30 -0700 | [diff] [blame] | 84 | read_unlock_bh(&ip_conntrack_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | return ret; |
| 86 | } |
| 87 | |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 88 | #else /* CONFIG_IP_NF_CONNTRACK */ |
| 89 | |
| 90 | static int |
| 91 | match(const struct sk_buff *skb, |
| 92 | const struct net_device *in, |
| 93 | const struct net_device *out, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 94 | const struct xt_match *match, |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 95 | const void *matchinfo, |
| 96 | int offset, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 97 | unsigned int protoff, |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 98 | int *hotdrop) |
| 99 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 100 | const struct xt_helper_info *info = matchinfo; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 101 | struct nf_conn *ct; |
Harald Welte | dc808fe | 2006-03-20 17:56:32 -0800 | [diff] [blame] | 102 | struct nf_conn_help *master_help; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 103 | enum ip_conntrack_info ctinfo; |
| 104 | int ret = info->invert; |
| 105 | |
| 106 | ct = nf_ct_get((struct sk_buff *)skb, &ctinfo); |
| 107 | if (!ct) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 108 | DEBUGP("xt_helper: Eek! invalid conntrack?\n"); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 109 | return ret; |
| 110 | } |
| 111 | |
| 112 | if (!ct->master) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 113 | DEBUGP("xt_helper: conntrack %p has no master\n", ct); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 114 | return ret; |
| 115 | } |
| 116 | |
| 117 | read_lock_bh(&nf_conntrack_lock); |
Harald Welte | dc808fe | 2006-03-20 17:56:32 -0800 | [diff] [blame] | 118 | master_help = nfct_help(ct->master); |
| 119 | if (!master_help || !master_help->helper) { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 120 | DEBUGP("xt_helper: master ct %p has no helper\n", |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 121 | exp->expectant); |
| 122 | goto out_unlock; |
| 123 | } |
| 124 | |
| 125 | DEBUGP("master's name = %s , info->name = %s\n", |
| 126 | ct->master->helper->name, info->name); |
| 127 | |
| 128 | if (info->name[0] == '\0') |
| 129 | ret ^= 1; |
| 130 | else |
Harald Welte | dc808fe | 2006-03-20 17:56:32 -0800 | [diff] [blame] | 131 | ret ^= !strncmp(master_help->helper->name, info->name, |
| 132 | strlen(master_help->helper->name)); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 133 | out_unlock: |
| 134 | read_unlock_bh(&nf_conntrack_lock); |
| 135 | return ret; |
| 136 | } |
| 137 | #endif |
| 138 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | static int check(const char *tablename, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 140 | const void *inf, |
Patrick McHardy | c498673 | 2006-03-20 18:02:56 -0800 | [diff] [blame] | 141 | const struct xt_match *match, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | void *matchinfo, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | unsigned int hook_mask) |
| 144 | { |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 145 | struct xt_helper_info *info = matchinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 147 | if (nf_ct_l3proto_try_module_get(match->family) < 0) { |
Yasuyuki Kozakai | fe0b929 | 2006-12-12 00:28:40 -0800 | [diff] [blame] | 148 | printk(KERN_WARNING "can't load conntrack support for " |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 149 | "proto=%d\n", match->family); |
| 150 | return 0; |
| 151 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | info->name[29] = '\0'; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | return 1; |
| 154 | } |
| 155 | |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 156 | static void |
Patrick McHardy | efa7416 | 2006-08-22 00:36:37 -0700 | [diff] [blame] | 157 | destroy(const struct xt_match *match, void *matchinfo) |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 158 | { |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 159 | nf_ct_l3proto_module_put(match->family); |
Pablo Neira Ayuso | b9f78f9 | 2006-03-22 13:56:08 -0800 | [diff] [blame] | 160 | } |
| 161 | |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 162 | static struct xt_match xt_helper_match[] = { |
| 163 | { |
| 164 | .name = "helper", |
| 165 | .family = AF_INET, |
| 166 | .checkentry = check, |
| 167 | .match = match, |
| 168 | .destroy = destroy, |
| 169 | .matchsize = sizeof(struct xt_helper_info), |
| 170 | .me = THIS_MODULE, |
| 171 | }, |
| 172 | { |
| 173 | .name = "helper", |
| 174 | .family = AF_INET6, |
| 175 | .checkentry = check, |
| 176 | .match = match, |
| 177 | .destroy = destroy, |
| 178 | .matchsize = sizeof(struct xt_helper_info), |
| 179 | .me = THIS_MODULE, |
| 180 | }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | }; |
| 182 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 183 | static int __init xt_helper_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 185 | return xt_register_matches(xt_helper_match, |
| 186 | ARRAY_SIZE(xt_helper_match)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | } |
| 188 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 189 | static void __exit xt_helper_fini(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 191 | xt_unregister_matches(xt_helper_match, ARRAY_SIZE(xt_helper_match)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | } |
| 193 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 194 | module_init(xt_helper_init); |
| 195 | module_exit(xt_helper_fini); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | |