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 struct xt_match *match,
  30       const void *matchinfo,
  31       int offset,
  32       unsigned int protoff,
  33       int *hotdrop)
  34 {
  35         const struct ip6t_owner_info *info = matchinfo;
  36
  37         if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
  38                 return 0;
  39
  40         if (info->match & IP6T_OWNER_UID) {
  41                 if ((skb->sk->sk_socket->file->f_uid != info->uid) ^
  42                     !!(info->invert & IP6T_OWNER_UID))
  43                         return 0;
  44         }
  45
  46         if (info->match & IP6T_OWNER_GID) {
  47                 if ((skb->sk->sk_socket->file->f_gid != info->gid) ^
  48                     !!(info->invert & IP6T_OWNER_GID))
  49                         return 0;
  50         }
  51
  52         return 1;
  53 }
  54
  55 static int
  56 checkentry(const char *tablename,
  57            const void *ip,
  58            const struct xt_match *match,
  59            void *matchinfo,
  60            unsigned int hook_mask)
  61 {
  62         const struct ip6t_owner_info *info = matchinfo;
  63
  64         if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) {
  65                 printk("ipt_owner: pid and sid matching "
  66                        "not supported anymore\n");
  67                 return 0;
  68         }
  69         return 1;
  70 }
  71
  72 static struct ip6t_match owner_match = {
  73         .name           = "owner",
  74         .match          = match,
  75         .matchsize      = sizeof(struct ip6t_owner_info),
  76         .hooks          = (1 << NF_IP6_LOCAL_OUT) | (1 << NF_IP6_POST_ROUTING),
  77         .checkentry     = checkentry,
  78         .me             = THIS_MODULE,
  79 };
  80
  81 static int __init ip6t_owner_init(void)
  82 {
  83         return ip6t_register_match(&owner_match);
  84 }
  85
  86 static void __exit ip6t_owner_fini(void)
  87 {
  88         ip6t_unregister_match(&owner_match);
  89 }
  90
  91 module_init(ip6t_owner_init);
  92 module_exit(ip6t_owner_fini);