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 65 connmark_mt_check_v0(const char *tablename, const void *ip, 66 const struct xt_match *match, void *matchinfo, 67 unsigned int hook_mask) 68 { 69 const struct xt_connmark_info *cm = matchinfo; 70 71 if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) { 72 printk(KERN_WARNING "connmark: only support 32bit mark\n"); 73 return false; 74 } 75 if (nf_ct_l3proto_try_module_get(match->family) < 0) { 76 printk(KERN_WARNING "can't load conntrack support for " 77 "proto=%u\n", match->family); 78 return false; 79 } 80 return true; 81 } 82 83 static bool 84 connmark_mt_check(const char *tablename, const void *ip, 85 const struct xt_match *match, void *matchinfo, 86 unsigned int hook_mask) 87 { 88 if (nf_ct_l3proto_try_module_get(match->family) < 0) { 89 printk(KERN_WARNING "cannot load conntrack support for " 90 "proto=%u\n", match->family); 91 return false; 92 } 93 return true; 94 } 95 96 static void 97 connmark_mt_destroy(const struct xt_match *match, void *matchinfo) 98 { 99 nf_ct_l3proto_module_put(match->family); 100 } 101 102 #ifdef CONFIG_COMPAT 103 struct compat_xt_connmark_info { 104 compat_ulong_t mark, mask; 105 u_int8_t invert; 106 u_int8_t __pad1; 107 u_int16_t __pad2; 108 }; 109 110 static void connmark_mt_compat_from_user_v0(void *dst, void *src) 111 { 112 const struct compat_xt_connmark_info *cm = src; 113 struct xt_connmark_info m = { 114 .mark = cm->mark, 115 .mask = cm->mask, 116 .invert = cm->invert, 117 }; 118 memcpy(dst, &m, sizeof(m)); 119 } 120 121 static int connmark_mt_compat_to_user_v0(void __user *dst, void *src) 122 { 123 const struct xt_connmark_info *m = src; 124 struct compat_xt_connmark_info cm = { 125 .mark = m->mark, 126 .mask = m->mask, 127 .invert = m->invert, 128 }; 129 return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; 130 } 131 #endif /* CONFIG_COMPAT */ 132 133 static struct xt_match connmark_mt_reg[] __read_mostly = { 134 { 135 .name = "connmark", 136 .revision = 0, 137 .family = NFPROTO_IPV4, 138 .checkentry = connmark_mt_check_v0, 139 .match = connmark_mt_v0, 140 .destroy = connmark_mt_destroy, 141 .matchsize = sizeof(struct xt_connmark_info), 142 #ifdef CONFIG_COMPAT 143 .compatsize = sizeof(struct compat_xt_connmark_info), 144 .compat_from_user = connmark_mt_compat_from_user_v0, 145 .compat_to_user = connmark_mt_compat_to_user_v0, 146 #endif 147 .me = THIS_MODULE 148 }, 149 { 150 .name = "connmark", 151 .revision = 0, 152 .family = NFPROTO_IPV6, 153 .checkentry = connmark_mt_check_v0, 154 .match = connmark_mt_v0, 155 .destroy = connmark_mt_destroy, 156 .matchsize = sizeof(struct xt_connmark_info), 157 #ifdef CONFIG_COMPAT 158 .compatsize = sizeof(struct compat_xt_connmark_info), 159 .compat_from_user = connmark_mt_compat_from_user_v0, 160 .compat_to_user = connmark_mt_compat_to_user_v0, 161 #endif 162 .me = THIS_MODULE 163 }, 164 { 165 .name = "connmark", 166 .revision = 1, 167 .family = NFPROTO_IPV4, 168 .checkentry = connmark_mt_check, 169 .match = connmark_mt, 170 .matchsize = sizeof(struct xt_connmark_mtinfo1), 171 .destroy = connmark_mt_destroy, 172 .me = THIS_MODULE, 173 }, 174 { 175 .name = "connmark", 176 .revision = 1, 177 .family = NFPROTO_IPV6, 178 .checkentry = connmark_mt_check, 179 .match = connmark_mt, 180 .matchsize = sizeof(struct xt_connmark_mtinfo1), 181 .destroy = connmark_mt_destroy, 182 .me = THIS_MODULE, 183 }, 184 }; 185 186 static int __init connmark_mt_init(void) 187 { 188 return xt_register_matches(connmark_mt_reg, 189 ARRAY_SIZE(connmark_mt_reg)); 190 } 191 192 static void __exit connmark_mt_exit(void) 193 { 194 xt_unregister_matches(connmark_mt_reg, ARRAY_SIZE(connmark_mt_reg)); 195 } 196 197 module_init(connmark_mt_init); 198 module_exit(connmark_mt_exit); 199