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 91 connmark_mt_destroy(const struct xt_match *match, void *matchinfo) 92 { 93 nf_ct_l3proto_module_put(match->family); 94 } 95 96 #ifdef CONFIG_COMPAT 97 struct compat_xt_connmark_info { 98 compat_ulong_t mark, mask; 99 u_int8_t invert; 100 u_int8_t __pad1; 101 u_int16_t __pad2; 102 }; 103 104 static void connmark_mt_compat_from_user_v0(void *dst, void *src) 105 { 106 const struct compat_xt_connmark_info *cm = src; 107 struct xt_connmark_info m = { 108 .mark = cm->mark, 109 .mask = cm->mask, 110 .invert = cm->invert, 111 }; 112 memcpy(dst, &m, sizeof(m)); 113 } 114 115 static int connmark_mt_compat_to_user_v0(void __user *dst, void *src) 116 { 117 const struct xt_connmark_info *m = src; 118 struct compat_xt_connmark_info cm = { 119 .mark = m->mark, 120 .mask = m->mask, 121 .invert = m->invert, 122 }; 123 return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; 124 } 125 #endif /* CONFIG_COMPAT */ 126 127 static struct xt_match connmark_mt_reg[] __read_mostly = { 128 { 129 .name = "connmark", 130 .revision = 0, 131 .family = NFPROTO_IPV4, 132 .checkentry = connmark_mt_check_v0, 133 .match = connmark_mt_v0, 134 .destroy = connmark_mt_destroy, 135 .matchsize = sizeof(struct xt_connmark_info), 136 #ifdef CONFIG_COMPAT 137 .compatsize = sizeof(struct compat_xt_connmark_info), 138 .compat_from_user = connmark_mt_compat_from_user_v0, 139 .compat_to_user = connmark_mt_compat_to_user_v0, 140 #endif 141 .me = THIS_MODULE 142 }, 143 { 144 .name = "connmark", 145 .revision = 0, 146 .family = NFPROTO_IPV6, 147 .checkentry = connmark_mt_check_v0, 148 .match = connmark_mt_v0, 149 .destroy = connmark_mt_destroy, 150 .matchsize = sizeof(struct xt_connmark_info), 151 #ifdef CONFIG_COMPAT 152 .compatsize = sizeof(struct compat_xt_connmark_info), 153 .compat_from_user = connmark_mt_compat_from_user_v0, 154 .compat_to_user = connmark_mt_compat_to_user_v0, 155 #endif 156 .me = THIS_MODULE 157 }, 158 { 159 .name = "connmark", 160 .revision = 1, 161 .family = NFPROTO_IPV4, 162 .checkentry = connmark_mt_check, 163 .match = connmark_mt, 164 .matchsize = sizeof(struct xt_connmark_mtinfo1), 165 .destroy = connmark_mt_destroy, 166 .me = THIS_MODULE, 167 }, 168 { 169 .name = "connmark", 170 .revision = 1, 171 .family = NFPROTO_IPV6, 172 .checkentry = connmark_mt_check, 173 .match = connmark_mt, 174 .matchsize = sizeof(struct xt_connmark_mtinfo1), 175 .destroy = connmark_mt_destroy, 176 .me = THIS_MODULE, 177 }, 178 }; 179 180 static int __init connmark_mt_init(void) 181 { 182 return xt_register_matches(connmark_mt_reg, 183 ARRAY_SIZE(connmark_mt_reg)); 184 } 185 186 static void __exit connmark_mt_exit(void) 187 { 188 xt_unregister_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg)); 189 } 190 191 module_init(connmark_mt_init); 192 module_exit(connmark_mt_exit); 193