net/ipv6/netfilter/ip6t_owner.c

   1 /* Kernel module to match various things tied to sockets associated with
   2    locally generated outgoing packets. */
   3
   4 /* (C) 2000-2001 Marc Boucher <marc@mbsi.ca>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/file.h>
  14 #include <linux/rcupdate.h>
  15 #include <net/sock.h>
  16
  17 #include <linux/netfilter_ipv6/ip6t_owner.h>
  18 #include <linux/netfilter_ipv6/ip6_tables.h>
  19
  20 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  21 MODULE_DESCRIPTION("IP6 tables owner matching module");
  22 MODULE_LICENSE("GPL");
  23
  24
  25 static int
  26 match(const struct sk_buff *skb,
  27       const struct net_device *in,
  28       const struct net_device *out,
  29       const void *matchinfo,
  30       int offset,
  31       unsigned int protoff,
  32       int *hotdrop)
  33 {
  34         const struct ip6t_owner_info *info = matchinfo;
  35
  36         if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
  37                 return 0;
  38
  39         if(info->match & IP6T_OWNER_UID) {
  40                 if((skb->sk->sk_socket->file->f_uid != info->uid) ^
  41                     !!(info->invert & IP6T_OWNER_UID))
  42                         return 0;
  43         }
  44
  45         if(info->match & IP6T_OWNER_GID) {
  46                 if((skb->sk->sk_socket->file->f_gid != info->gid) ^
  47                     !!(info->invert & IP6T_OWNER_GID))
  48                         return 0;
  49         }
  50
  51         return 1;
  52 }
  53
  54 static int
  55 checkentry(const char *tablename,
  56            const struct ip6t_ip6 *ip,
  57            void *matchinfo,
  58            unsigned int matchsize,
  59            unsigned int hook_mask)
  60 {
  61         const struct ip6t_owner_info *info = matchinfo;
  62
  63         if (hook_mask
  64             & ~((1 << NF_IP6_LOCAL_OUT) | (1 << NF_IP6_POST_ROUTING))) {
  65                 printk("ip6t_owner: only valid for LOCAL_OUT or POST_ROUTING.\n");
  66                 return 0;
  67         }
  68
  69         if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_owner_info)))
  70                 return 0;
  71
  72         if (info->match & (IP6T_OWNER_PID|IP6T_OWNER_SID)) {
  73                 printk("ipt_owner: pid and sid matching "
  74                        "not supported anymore\n");
  75                 return 0;
  76         }
  77
  78         return 1;
  79 }
  80
  81 static struct ip6t_match owner_match = {
  82         .name           = "owner",
  83         .match          = &match,
  84         .checkentry     = &checkentry,
  85         .me             = THIS_MODULE,
  86 };
  87
  88 static int __init init(void)
  89 {
  90         return ip6t_register_match(&owner_match);
  91 }
  92
  93 static void __exit fini(void)
  94 {
  95         ip6t_unregister_match(&owner_match);
  96 }
  97
  98 module_init(init);
  99 module_exit(fini);