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 {
  32         const struct xt_mark_target_info *markinfo = targinfo;
  33
  34         (*pskb)->mark = markinfo->mark;
  35         return XT_CONTINUE;
  36 }
  37
  38 static unsigned int
  39 target_v1(struct sk_buff **pskb,
  40           const struct net_device *in,
  41           const struct net_device *out,
  42           unsigned int hooknum,
  43           const struct xt_target *target,
  44           const void *targinfo)
  45 {
  46         const struct xt_mark_target_info_v1 *markinfo = targinfo;
  47         int mark = 0;
  48
  49         switch (markinfo->mode) {
  50         case XT_MARK_SET:
  51                 mark = markinfo->mark;
  52                 break;
  53
  54         case XT_MARK_AND:
  55                 mark = (*pskb)->mark & markinfo->mark;
  56                 break;
  57
  58         case XT_MARK_OR:
  59                 mark = (*pskb)->mark | markinfo->mark;
  60                 break;
  61         }
  62
  63         (*pskb)->mark = mark;
  64         return XT_CONTINUE;
  65 }
  66
  67
  68 static bool
  69 checkentry_v0(const char *tablename,
  70               const void *entry,
  71               const struct xt_target *target,
  72               void *targinfo,
  73               unsigned int hook_mask)
  74 {
  75         const struct xt_mark_target_info *markinfo = targinfo;
  76
  77         if (markinfo->mark > 0xffffffff) {
  78                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
  79                 return false;
  80         }
  81         return true;
  82 }
  83
  84 static bool
  85 checkentry_v1(const char *tablename,
  86               const void *entry,
  87               const struct xt_target *target,
  88               void *targinfo,
  89               unsigned int hook_mask)
  90 {
  91         const struct xt_mark_target_info_v1 *markinfo = targinfo;
  92
  93         if (markinfo->mode != XT_MARK_SET
  94             && markinfo->mode != XT_MARK_AND
  95             && markinfo->mode != XT_MARK_OR) {
  96                 printk(KERN_WARNING "MARK: unknown mode %u\n",
  97                        markinfo->mode);
  98                 return false;
  99         }
 100         if (markinfo->mark > 0xffffffff) {
 101                 printk(KERN_WARNING "MARK: Only supports 32bit wide mark\n");
 102                 return false;
 103         }
 104         return true;
 105 }
 106
 107 #ifdef CONFIG_COMPAT
 108 struct compat_xt_mark_target_info_v1 {
 109         compat_ulong_t  mark;
 110         u_int8_t        mode;
 111         u_int8_t        __pad1;
 112         u_int16_t       __pad2;
 113 };
 114
 115 static void compat_from_user_v1(void *dst, void *src)
 116 {
 117         const struct compat_xt_mark_target_info_v1 *cm = src;
 118         struct xt_mark_target_info_v1 m = {
 119                 .mark   = cm->mark,
 120                 .mode   = cm->mode,
 121         };
 122         memcpy(dst, &m, sizeof(m));
 123 }
 124
 125 static int compat_to_user_v1(void __user *dst, void *src)
 126 {
 127         const struct xt_mark_target_info_v1 *m = src;
 128         struct compat_xt_mark_target_info_v1 cm = {
 129                 .mark   = m->mark,
 130                 .mode   = m->mode,
 131         };
 132         return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0;
 133 }
 134 #endif /* CONFIG_COMPAT */
 135
 136 static struct xt_target xt_mark_target[] __read_mostly = {
 137         {
 138                 .name           = "MARK",
 139                 .family         = AF_INET,
 140                 .revision       = 0,
 141                 .checkentry     = checkentry_v0,
 142                 .target         = target_v0,
 143                 .targetsize     = sizeof(struct xt_mark_target_info),
 144                 .table          = "mangle",
 145                 .me             = THIS_MODULE,
 146         },
 147         {
 148                 .name           = "MARK",
 149                 .family         = AF_INET,
 150                 .revision       = 1,
 151                 .checkentry     = checkentry_v1,
 152                 .target         = target_v1,
 153                 .targetsize     = sizeof(struct xt_mark_target_info_v1),
 154 #ifdef CONFIG_COMPAT
 155                 .compatsize     = sizeof(struct compat_xt_mark_target_info_v1),
 156                 .compat_from_user = compat_from_user_v1,
 157                 .compat_to_user = compat_to_user_v1,
 158 #endif
 159                 .table          = "mangle",
 160                 .me             = THIS_MODULE,
 161         },
 162         {
 163                 .name           = "MARK",
 164                 .family         = AF_INET6,
 165                 .revision       = 0,
 166                 .checkentry     = checkentry_v0,
 167                 .target         = target_v0,
 168                 .targetsize     = sizeof(struct xt_mark_target_info),
 169                 .table          = "mangle",
 170                 .me             = THIS_MODULE,
 171         },
 172 };
 173
 174 static int __init xt_mark_init(void)
 175 {
 176         return xt_register_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
 177 }
 178
 179 static void __exit xt_mark_fini(void)
 180 {
 181         xt_unregister_targets(xt_mark_target, ARRAY_SIZE(xt_mark_target));
 182 }
 183
 184 module_init(xt_mark_init);
 185 module_exit(xt_mark_fini);