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 struct xt_target *target,
  30           const void *targinfo,
  31           void *userinfo)
  32 {
  33         const struct xt_mark_target_info *markinfo = targinfo;
  34
  35         if((*pskb)->nfmark != markinfo->mark)
  36                 (*pskb)->nfmark = markinfo->mark;
  37
  38         return XT_CONTINUE;
  39 }
  40
  41 static unsigned int
  42 target_v1(struct sk_buff **pskb,
  43           const struct net_device *in,
  44           const struct net_device *out,
  45           unsigned int hooknum,
  46           const struct xt_target *target,
  47           const void *targinfo,
  48           void *userinfo)
  49 {
  50         const struct xt_mark_target_info_v1 *markinfo = targinfo;
  51         int mark = 0;
  52
  53         switch (markinfo->mode) {
  54         case XT_MARK_SET:
  55                 mark = markinfo->mark;
  56                 break;
  57
  58         case XT_MARK_AND:
  59                 mark = (*pskb)->nfmark & markinfo->mark;
  60                 break;
  61
  62         case XT_MARK_OR:
  63                 mark = (*pskb)->nfmark | markinfo->mark;
  64                 break;
  65         }
  66
  67         if((*pskb)->nfmark != mark)
  68                 (*pskb)->nfmark = mark;
  69
  70         return XT_CONTINUE;
  71 }
  72
  73
  74 static int
  75 checkentry_v0(const char *tablename,
  76               const void *entry,
  77               const struct xt_target *target,
  78               void *targinfo,
  79               unsigned int targinfosize,
  80               unsigned int hook_mask)
  81 {
  82         struct xt_mark_target_info *markinfo = targinfo;
  83
  84         if (markinfo->mark > 0xffffffff) {
  85                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
  86                 return 0;
  87         }
  88         return 1;
  89 }
  90
  91 static int
  92 checkentry_v1(const char *tablename,
  93               const void *entry,
  94               const struct xt_target *target,
  95               void *targinfo,
  96               unsigned int targinfosize,
  97               unsigned int hook_mask)
  98 {
  99         struct xt_mark_target_info_v1 *markinfo = targinfo;
 100
 101         if (markinfo->mode != XT_MARK_SET
 102             && markinfo->mode != XT_MARK_AND
 103             && markinfo->mode != XT_MARK_OR) {
 104                 printk(KERN_WARNING "MARK: unknown mode %u\n",
 105                        markinfo->mode);
 106                 return 0;
 107         }
 108         if (markinfo->mark > 0xffffffff) {
 109                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
 110                 return 0;
 111         }
 112         return 1;
 113 }
 114
 115 static struct xt_target ipt_mark_reg_v0 = {
 116         .name           = "MARK",
 117         .target         = target_v0,
 118         .targetsize     = sizeof(struct xt_mark_target_info),
 119         .table          = "mangle",
 120         .checkentry     = checkentry_v0,
 121         .me             = THIS_MODULE,
 122         .revision       = 0,
 123 };
 124
 125 static struct xt_target ipt_mark_reg_v1 = {
 126         .name           = "MARK",
 127         .target         = target_v1,
 128         .targetsize     = sizeof(struct xt_mark_target_info_v1),
 129         .table          = "mangle",
 130         .checkentry     = checkentry_v1,
 131         .me             = THIS_MODULE,
 132         .revision       = 1,
 133 };
 134
 135 static struct xt_target ip6t_mark_reg_v0 = {
 136         .name           = "MARK",
 137         .target         = target_v0,
 138         .targetsize     = sizeof(struct xt_mark_target_info),
 139         .table          = "mangle",
 140         .checkentry     = checkentry_v0,
 141         .me             = THIS_MODULE,
 142         .revision       = 0,
 143 };
 144
 145 static int __init init(void)
 146 {
 147         int err;
 148
 149         err = xt_register_target(AF_INET, &ipt_mark_reg_v0);
 150         if (err)
 151                 return err;
 152
 153         err = xt_register_target(AF_INET, &ipt_mark_reg_v1);
 154         if (err)
 155                 xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 156
 157         err = xt_register_target(AF_INET6, &ip6t_mark_reg_v0);
 158         if (err) {
 159                 xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 160                 xt_unregister_target(AF_INET, &ipt_mark_reg_v1);
 161         }
 162
 163         return err;
 164 }
 165
 166 static void __exit fini(void)
 167 {
 168         xt_unregister_target(AF_INET, &ipt_mark_reg_v0);
 169         xt_unregister_target(AF_INET, &ipt_mark_reg_v1);
 170         xt_unregister_target(AF_INET6, &ip6t_mark_reg_v0);
 171 }
 172
 173 module_init(init);
 174 module_exit(fini);