net/netfilter/xt_MARK.c

   1 /* This is a module which is used for setting the NFMARK field of an skb. */
   2
   3 /* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/ip.h>
  13 #include <net/checksum.h>
  14
  15 #include <linux/netfilter/x_tables.h>
  16 #include <linux/netfilter/xt_MARK.h>
  17
  18 MODULE_LICENSE("GPL");
  19 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  20 MODULE_DESCRIPTION("ip[6]tables MARK modification module");
  21 MODULE_ALIAS("ipt_MARK");
  22 MODULE_ALIAS("ip6t_MARK");
  23
  24 static unsigned int
  25 target_v0(struct sk_buff **pskb,
  26           const struct net_device *in,
  27           const struct net_device *out,
  28           unsigned int hooknum,
  29           const void *targinfo,
  30           void *userinfo)
  31 {
  32         const struct xt_mark_target_info *markinfo = targinfo;
  33
  34         if((*pskb)->nfmark != markinfo->mark)
  35                 (*pskb)->nfmark = markinfo->mark;
  36
  37         return XT_CONTINUE;
  38 }
  39
  40 static unsigned int
  41 target_v1(struct sk_buff **pskb,
  42           const struct net_device *in,
  43           const struct net_device *out,
  44           unsigned int hooknum,
  45           const void *targinfo,
  46           void *userinfo)
  47 {
  48         const struct xt_mark_target_info_v1 *markinfo = targinfo;
  49         int mark = 0;
  50
  51         switch (markinfo->mode) {
  52         case XT_MARK_SET:
  53                 mark = markinfo->mark;
  54                 break;
  55
  56         case XT_MARK_AND:
  57                 mark = (*pskb)->nfmark & markinfo->mark;
  58                 break;
  59
  60         case XT_MARK_OR:
  61                 mark = (*pskb)->nfmark | markinfo->mark;
  62                 break;
  63         }
  64
  65         if((*pskb)->nfmark != mark)
  66                 (*pskb)->nfmark = mark;
  67
  68         return XT_CONTINUE;
  69 }
  70
  71
  72 static int
  73 checkentry_v0(const char *tablename,
  74               const void *entry,
  75               void *targinfo,
  76               unsigned int targinfosize,
  77               unsigned int hook_mask)
  78 {
  79         struct xt_mark_target_info *markinfo = targinfo;
  80
  81         if (targinfosize != XT_ALIGN(sizeof(struct xt_mark_target_info))) {
  82                 printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
  83                        targinfosize,
  84                        XT_ALIGN(sizeof(struct xt_mark_target_info)));
  85                 return 0;
  86         }
  87
  88         if (strcmp(tablename, "mangle") != 0) {
  89                 printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
  90                 return 0;
  91         }
  92
  93         if (markinfo->mark > 0xffffffff) {
  94                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
  95                 return 0;
  96         }
  97
  98         return 1;
  99 }
 100
 101 static int
 102 checkentry_v1(const char *tablename,
 103               const void *entry,
 104               void *targinfo,
 105               unsigned int targinfosize,
 106               unsigned int hook_mask)
 107 {
 108         struct xt_mark_target_info_v1 *markinfo = targinfo;
 109
 110         if (targinfosize != XT_ALIGN(sizeof(struct xt_mark_target_info_v1))){
 111                 printk(KERN_WARNING "MARK: targinfosize %u != %Zu\n",
 112                        targinfosize,
 113                        XT_ALIGN(sizeof(struct xt_mark_target_info_v1)));
 114                 return 0;
 115         }
 116
 117         if (strcmp(tablename, "mangle") != 0) {
 118                 printk(KERN_WARNING "MARK: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
 119                 return 0;
 120         }
 121
 122         if (markinfo->mode != XT_MARK_SET
 123             && markinfo->mode != XT_MARK_AND
 124             && markinfo->mode != XT_MARK_OR) {
 125                 printk(KERN_WARNING "MARK: unknown mode %u\n",
 126                        markinfo->mode);
 127                 return 0;
 128         }
 129
 130         if (markinfo->mark > 0xffffffff) {
 131                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
 132                 return 0;
 133         }
 134
 135         return 1;
 136 }
 137
 138 static struct xt_target ipt_mark_reg_v0 = {
 139         .name           = "MARK",
 140         .target         = target_v0,
 141         .checkentry     = checkentry_v0,
 142         .me             = THIS_MODULE,
 143         .revision       = 0,
 144 };
 145
 146 static struct xt_target ipt_mark_reg_v1 = {
 147         .name           = "MARK",
 148         .target         = target_v1,
 149         .checkentry     = checkentry_v1,
 150         .me             = THIS_MODULE,
 151         .revision       = 1,
 152 };
 153
 154 static struct xt_target ip6t_mark_reg_v0 = {
 155         .name           = "MARK",
 156         .target         = target_v0,
 157         .checkentry     = checkentry_v0,
 158         .me             = THIS_MODULE,
 159         .revision       = 0,
 160 };
 161
 162 static int __init init(void)
 163 {
 164         int err;
 165
 166         err = xt_register_target(AF_INET, &ipt_mark_reg_v0);
 167         if (err)
 168                 return err;
 169
 170         err = xt_register_target(AF_INET, &ipt_mark_reg_v1);
 171         if (err)
 172                 xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 173
 174         err = xt_register_target(AF_INET6, &ip6t_mark_reg_v0);
 175         if (err) {
 176                 xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 177                 xt_unregister_target(AF_INET, &ipt_mark_reg_v1);
 178         }
 179
 180         return err;
 181 }
 182
 183 static void __exit fini(void)
 184 {
 185         xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 186         xt_unregister_target(AF_INET, &ipt_mark_reg_v1);
 187         xt_unregister_target(AF_INET6, &ip6t_mark_reg_v0);
 188 }
 189
 190 module_init(init);
 191 module_exit(fini);