[PATCH] files: lock-free fd look-up
[linux-2.6.git] / 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);