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 matchsize, 59 unsigned int hook_mask) 60 { 61 struct xt_connmark_info *cm = (struct xt_connmark_info *)matchinfo; 62 63 if (cm->mark > 0xffffffff || cm->mask > 0xffffffff) { 64 printk(KERN_WARNING "connmark: only support 32bit mark\n"); 65 return 0; 66 } 67 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 68 if (nf_ct_l3proto_try_module_get(match->family) < 0) { 69 printk(KERN_WARNING "can't load nf_conntrack support for " 70 "proto=%d\n", match->family); 71 return 0; 72 } 73 #endif 74 return 1; 75 } 76 77 static void 78 destroy(const struct xt_match *match, void *matchinfo, unsigned int matchsize) 79 { 80 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 81 nf_ct_l3proto_module_put(match->family); 82 #endif 83 } 84 85 static struct xt_match connmark_match = { 86 .name = "connmark", 87 .match = match, 88 .matchsize = sizeof(struct xt_connmark_info), 89 .checkentry = checkentry, 90 .destroy = destroy, 91 .family = AF_INET, 92 .me = THIS_MODULE 93 }; 94 95 static struct xt_match connmark6_match = { 96 .name = "connmark", 97 .match = match, 98 .matchsize = sizeof(struct xt_connmark_info), 99 .checkentry = checkentry, 100 .destroy = destroy, 101 .family = AF_INET6, 102 .me = THIS_MODULE 103 }; 104 105 static int __init init(void) 106 { 107 int ret; 108 109 need_conntrack(); 110 111 ret = xt_register_match(&connmark_match); 112 if (ret) 113 return ret; 114 115 ret = xt_register_match(&connmark6_match); 116 if (ret) 117 xt_unregister_match(&connmark_match); 118 return ret; 119 } 120 121 static void __exit fini(void) 122 { 123 xt_unregister_match(&connmark6_match); 124 xt_unregister_match(&connmark_match); 125 } 126 127 module_init(init); 128 module_exit(fini); 129