1 /* This kernel module matches connection mark values set by the 2 * CONNMARK target 3 * 4 * Copyright (C) 2002,2004 MARA Systems AB <http://www.marasystems.com> 5 * by Henrik Nordstrom <hno@marasystems.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/module.h> 23 #include <linux/skbuff.h> 24 25 MODULE_AUTHOR("Henrik Nordstrom <hno@marasytems.com>"); 26 MODULE_DESCRIPTION("IP tables connmark match module"); 27 MODULE_LICENSE("GPL"); 28 MODULE_ALIAS("ipt_connmark"); 29 30 #include <linux/netfilter/x_tables.h> 31 #include <linux/netfilter/xt_connmark.h> 32 #include <net/netfilter/nf_conntrack_compat.h> 33 34 static int 35 match(const struct sk_buff *skb, 36 const struct net_device *in, 37 const struct net_device *out, 38 const struct xt_match *match, 39 const void *matchinfo, 40 int offset, 41 unsigned int protoff, 42 int *hotdrop) 43 { 44 const struct xt_connmark_info *info = matchinfo; 45 u_int32_t ctinfo; 46 const u_int32_t *ctmark = nf_ct_get_mark(skb, &ctinfo); 47 if (!ctmark) 48 return 0; 49 50 return (((*ctmark) & info->mask) == info->mark) ^ info->invert; 51 } 52 53 static int 54 checkentry(const char *tablename, 55 const void *ip, 56 const struct xt_match *match, 57 void *matchinfo, 58 unsigned int hook_mask) 59 { 60 struct xt_connmark_info *cm = matchinfo; 61 62 if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) { 63 printk(KERN_WARNING "connmark: only support 32bit mark\n"); 64 return 0; 65 } 66 if (nf_ct_l3proto_try_module_get(match->family) < 0) { 67 printk(KERN_WARNING "can't load conntrack support for " 68 "proto=%d\n", match->family); 69 return 0; 70 } 71 return 1; 72 } 73 74 static void 75 destroy(const struct xt_match *match, void *matchinfo) 76 { 77 nf_ct_l3proto_module_put(match->family); 78 } 79 80 #ifdef CONFIG_COMPAT 81 struct compat_xt_connmark_info { 82 compat_ulong_t mark, mask; 83 u_int8_t invert; 84 u_int8_t __pad1; 85 u_int16_t __pad2; 86 }; 87 88 static void compat_from_user(void *dst, void *src) 89 { 90 struct compat_xt_connmark_info *cm = src; 91 struct xt_connmark_info m = { 92 .mark = cm->mark, 93 .mask = cm->mask, 94 .invert = cm->invert, 95 }; 96 memcpy(dst, &m, sizeof(m)); 97 } 98 99 static int compat_to_user(void __user *dst, void *src) 100 { 101 struct xt_connmark_info *m = src; 102 struct compat_xt_connmark_info cm = { 103 .mark = m->mark, 104 .mask = m->mask, 105 .invert = m->invert, 106 }; 107 return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; 108 } 109 #endif /* CONFIG_COMPAT */ 110 111 static struct xt_match xt_connmark_match[] = { 112 { 113 .name = "connmark", 114 .family = AF_INET, 115 .checkentry = checkentry, 116 .match = match, 117 .destroy = destroy, 118 .matchsize = sizeof(struct xt_connmark_info), 119 #ifdef CONFIG_COMPAT 120 .compatsize = sizeof(struct compat_xt_connmark_info), 121 .compat_from_user = compat_from_user, 122 .compat_to_user = compat_to_user, 123 #endif 124 .me = THIS_MODULE 125 }, 126 { 127 .name = "connmark", 128 .family = AF_INET6, 129 .checkentry = checkentry, 130 .match = match, 131 .destroy = destroy, 132 .matchsize = sizeof(struct xt_connmark_info), 133 .me = THIS_MODULE 134 }, 135 }; 136 137 static int __init xt_connmark_init(void) 138 { 139 return xt_register_matches(xt_connmark_match, 140 ARRAY_SIZE(xt_connmark_match)); 141 } 142 143 static void __exit xt_connmark_fini(void) 144 { 145 xt_unregister_matches(xt_connmark_match, ARRAY_SIZE(xt_connmark_match)); 146 } 147 148 module_init(xt_connmark_init); 149 module_exit(xt_connmark_fini); 150