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 #include <linux/netfilter/x_tables.h>
  20
  21 MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
  22 MODULE_DESCRIPTION("IP6 tables owner matching module");
  23 MODULE_LICENSE("GPL");
  24
  25
  26 static int
  27 match(const struct sk_buff *skb,
  28       const struct net_device *in,
  29       const struct net_device *out,
  30       const struct xt_match *match,
  31       const void *matchinfo,
  32       int offset,
  33       unsigned int protoff,
  34       int *hotdrop)
  35 {
  36         const struct ip6t_owner_info *info = matchinfo;
  37
  38         if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
  39                 return 0;
  40
  41         if (info->match & IP6T_OWNER_UID) {
  42                 if ((skb->sk->sk_socket->file->f_uid != info->uid) ^
  43                     !!(info->invert & IP6T_OWNER_UID))
  44                         return 0;
  45         }
  46
  47         if (info->match & IP6T_OWNER_GID) {
  48                 if ((skb->sk->sk_socket->file->f_gid != info->gid) ^
  49                     !!(info->invert & IP6T_OWNER_GID))
  50                         return 0;
  51         }
  52
  53         return 1;
  54 }
  55
  56 static int
  57 checkentry(const char *tablename,
  58            const void *ip,
  59            const struct xt_match *match,
  60            void *matchinfo,
  61            unsigned int hook_mask)
  62 {
  63         const struct ip6t_owner_info *info = matchinfo;
  64
  65         if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) {
  66                 printk("ipt_owner: pid and sid matching "
  67                        "not supported anymore\n");
  68                 return 0;
  69         }
  70         return 1;
  71 }
  72
  73 static struct xt_match owner_match = {
  74         .name           = "owner",
  75         .family         = AF_INET6,
  76         .match          = match,
  77         .matchsize      = sizeof(struct ip6t_owner_info),
  78         .hooks          = (1 << NF_IP6_LOCAL_OUT) | (1 << NF_IP6_POST_ROUTING),
  79         .checkentry     = checkentry,
  80         .me             = THIS_MODULE,
  81 };
  82
  83 static int __init ip6t_owner_init(void)
  84 {
  85         return xt_register_match(&owner_match);
  86 }
  87
  88 static void __exit ip6t_owner_fini(void)
  89 {
  90         xt_unregister_match(&owner_match);
  91 }
  92
  93 module_init(ip6t_owner_init);
  94 module_exit(ip6t_owner_fini);