1 /* 2 * xt_connmark - Netfilter module to match connection mark values 3 * 4 * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com> 5 * by Henrik Nordstrom <hno@marasystems.com> 6 * Copyright © CC Computer Consultants GmbH, 2007 - 2008 7 * Jan Engelhardt <jengelh@computergmbh.de> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 22 */ 23 24 #include <linux/module.h> 25 #include <linux/skbuff.h> 26 #include <net/netfilter/nf_conntrack.h> 27 #include <linux/netfilter/x_tables.h> 28 #include <linux/netfilter/xt_connmark.h> 29 30 MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>"); 31 MODULE_DESCRIPTION("Xtables: connection mark match"); 32 MODULE_LICENSE("GPL"); 33 MODULE_ALIAS("ipt_connmark"); 34 MODULE_ALIAS("ip6t_connmark"); 35 36 static bool 37 connmark_mt(const struct sk_buff *skb, const struct xt_match_param *par) 38 { 39 const struct xt_connmark_mtinfo1 *info = par->matchinfo; 40 enum ip_conntrack_info ctinfo; 41 const struct nf_conn *ct; 42 43 ct = nf_ct_get(skb, &ctinfo); 44 if (ct == NULL) 45 return false; 46 47 return ((ct->mark & info->mask) == info->mark) ^ info->invert; 48 } 49 50 static bool 51 connmark_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par) 52 { 53 const struct xt_connmark_info *info = par->matchinfo; 54 const struct nf_conn *ct; 55 enum ip_conntrack_info ctinfo; 56 57 ct = nf_ct_get(skb, &ctinfo); 58 if (!ct) 59 return false; 60 61 return ((ct->mark & info->mask) == info->mark) ^ info->invert; 62 } 63 64 static bool connmark_mt_check_v0(const struct xt_mtchk_param *par) 65 { 66 const struct xt_connmark_info *cm = par->matchinfo; 67 68 if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) { 69 printk(KERN_WARNING "connmark: only support 32bit mark\n"); 70 return false; 71 } 72 if (nf_ct_l3proto_try_module_get(par->match->family) < 0) { 73 printk(KERN_WARNING "can't load conntrack support for " 74 "proto=%u\n", par->match->family); 75 return false; 76 } 77 return true; 78 } 79 80 static bool connmark_mt_check(const struct xt_mtchk_param *par) 81 { 82 if (nf_ct_l3proto_try_module_get(par->match->family) < 0) { 83 printk(KERN_WARNING "cannot load conntrack support for " 84 "proto=%u\n", par->match->family); 85 return false; 86 } 87 return true; 88 } 89 90 static void connmark_mt_destroy(const struct xt_mtdtor_param *par) 91 { 92 nf_ct_l3proto_module_put(par->match->family); 93 } 94 95 #ifdef CONFIG_COMPAT 96 struct compat_xt_connmark_info { 97 compat_ulong_t mark, mask; 98 u_int8_t invert; 99 u_int8_t __pad1; 100 u_int16_t __pad2; 101 }; 102 103 static void connmark_mt_compat_from_user_v0(void *dst, void *src) 104 { 105 const struct compat_xt_connmark_info *cm = src; 106 struct xt_connmark_info m = { 107 .mark = cm->mark, 108 .mask = cm->mask, 109 .invert = cm->invert, 110 }; 111 memcpy(dst, &m, sizeof(m)); 112 } 113 114 static int connmark_mt_compat_to_user_v0(void __user *dst, void *src) 115 { 116 const struct xt_connmark_info *m = src; 117 struct compat_xt_connmark_info cm = { 118 .mark = m->mark, 119 .mask = m->mask, 120 .invert = m->invert, 121 }; 122 return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; 123 } 124 #endif /* CONFIG_COMPAT */ 125 126 static struct xt_match connmark_mt_reg[] __read_mostly = { 127 { 128 .name = "connmark", 129 .revision = 0, 130 .family = NFPROTO_IPV4, 131 .checkentry = connmark_mt_check_v0, 132 .match = connmark_mt_v0, 133 .destroy = connmark_mt_destroy, 134 .matchsize = sizeof(struct xt_connmark_info), 135 #ifdef CONFIG_COMPAT 136 .compatsize = sizeof(struct compat_xt_connmark_info), 137 .compat_from_user = connmark_mt_compat_from_user_v0, 138 .compat_to_user = connmark_mt_compat_to_user_v0, 139 #endif 140 .me = THIS_MODULE 141 }, 142 { 143 .name = "connmark", 144 .revision = 0, 145 .family = NFPROTO_IPV6, 146 .checkentry = connmark_mt_check_v0, 147 .match = connmark_mt_v0, 148 .destroy = connmark_mt_destroy, 149 .matchsize = sizeof(struct xt_connmark_info), 150 #ifdef CONFIG_COMPAT 151 .compatsize = sizeof(struct compat_xt_connmark_info), 152 .compat_from_user = connmark_mt_compat_from_user_v0, 153 .compat_to_user = connmark_mt_compat_to_user_v0, 154 #endif 155 .me = THIS_MODULE 156 }, 157 { 158 .name = "connmark", 159 .revision = 1, 160 .family = NFPROTO_IPV4, 161 .checkentry = connmark_mt_check, 162 .match = connmark_mt, 163 .matchsize = sizeof(struct xt_connmark_mtinfo1), 164 .destroy = connmark_mt_destroy, 165 .me = THIS_MODULE, 166 }, 167 { 168 .name = "connmark", 169 .revision = 1, 170 .family = NFPROTO_IPV6, 171 .checkentry = connmark_mt_check, 172 .match = connmark_mt, 173 .matchsize = sizeof(struct xt_connmark_mtinfo1), 174 .destroy = connmark_mt_destroy, 175 .me = THIS_MODULE, 176 }, 177 }; 178 179 static int __init connmark_mt_init(void) 180 { 181 return xt_register_matches(connmark_mt_reg, 182 ARRAY_SIZE(connmark_mt_reg)); 183 } 184 185 static void __exit connmark_mt_exit(void) 186 { 187 xt_unregister_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg)); 188 } 189 190 module_init(connmark_mt_init); 191 module_exit(connmark_mt_exit); 192