tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Kernel module to match various things tied to sockets associated with
3 * locally generated outgoing packets.
4 *
5 * (C) 2000 Marc Boucher <marc@mbsi.ca>
6 *
7 * Copyright © CC Computer Consultants GmbH, 2007 - 2008
8 * <jengelh@computergmbh.de>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14#include <linux/module.h>
15#include <linux/skbuff.h>
16#include <linux/file.h>
17#include <net/sock.h>
18#include <linux/netfilter/x_tables.h>
19#include <linux/netfilter/xt_owner.h>
20#include <linux/netfilter_ipv4/ipt_owner.h>
21#include <linux/netfilter_ipv6/ip6t_owner.h>
22
23static bool
24owner_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
25{
26 const struct ipt_owner_info *info = par->matchinfo;
27 const struct file *filp;
28
29 if (skb->sk == NULL || skb->sk->sk_socket == NULL)
30 return false;
31
32 filp = skb->sk->sk_socket->file;
33 if (filp == NULL)
34 return false;
35
36 if (info->match & IPT_OWNER_UID)
37 if ((filp->f_uid != info->uid) ^
38 !!(info->invert & IPT_OWNER_UID))
39 return false;
40
41 if (info->match & IPT_OWNER_GID)
42 if ((filp->f_gid != info->gid) ^
43 !!(info->invert & IPT_OWNER_GID))
44 return false;
45
46 return true;
47}
48
49static bool
50owner_mt6_v0(const struct sk_buff *skb, const struct xt_match_param *par)
51{
52 const struct ip6t_owner_info *info = par->matchinfo;
53 const struct file *filp;
54
55 if (skb->sk == NULL || skb->sk->sk_socket == NULL)
56 return false;
57
58 filp = skb->sk->sk_socket->file;
59 if (filp == NULL)
60 return false;
61
62 if (info->match & IP6T_OWNER_UID)
63 if ((filp->f_uid != info->uid) ^
64 !!(info->invert & IP6T_OWNER_UID))
65 return false;
66
67 if (info->match & IP6T_OWNER_GID)
68 if ((filp->f_gid != info->gid) ^
69 !!(info->invert & IP6T_OWNER_GID))
70 return false;
71
72 return true;
73}
74
75static bool
76owner_mt(const struct sk_buff *skb, const struct xt_match_param *par)
77{
78 const struct xt_owner_match_info *info = par->matchinfo;
79 const struct file *filp;
80
81 if (skb->sk == NULL || skb->sk->sk_socket == NULL)
82 return (info->match ^ info->invert) == 0;
83 else if (info->match & info->invert & XT_OWNER_SOCKET)
84 /*
85 * Socket exists but user wanted ! --socket-exists.
86 * (Single ampersands intended.)
87 */
88 return false;
89
90 filp = skb->sk->sk_socket->file;
91 if (filp == NULL)
92 return ((info->match ^ info->invert) &
93 (XT_OWNER_UID | XT_OWNER_GID)) == 0;
94
95 if (info->match & XT_OWNER_UID)
96 if ((filp->f_uid >= info->uid_min &&
97 filp->f_uid <= info->uid_max) ^
98 !(info->invert & XT_OWNER_UID))
99 return false;
100
101 if (info->match & XT_OWNER_GID)
102 if ((filp->f_gid >= info->gid_min &&
103 filp->f_gid <= info->gid_max) ^
104 !(info->invert & XT_OWNER_GID))
105 return false;
106
107 return true;
108}
109
110static bool owner_mt_check_v0(const struct xt_mtchk_param *par)
111{
112 const struct ipt_owner_info *info = par->matchinfo;
113
114 if (info->match & (IPT_OWNER_PID | IPT_OWNER_SID | IPT_OWNER_COMM)) {
115 printk(KERN_WARNING KBUILD_MODNAME
116 ": PID, SID and command matching is not "
117 "supported anymore\n");
118 return false;
119 }
120
121 return true;
122}
123
124static bool owner_mt6_check_v0(const struct xt_mtchk_param *par)
125{
126 const struct ip6t_owner_info *info = par->matchinfo;
127
128 if (info->match & (IP6T_OWNER_PID | IP6T_OWNER_SID)) {
129 printk(KERN_WARNING KBUILD_MODNAME
130 ": PID and SID matching is not supported anymore\n");
131 return false;
132 }
133
134 return true;
135}
136
137static struct xt_match owner_mt_reg[] __read_mostly = {
138 {
139 .name = "owner",
140 .revision = 0,
141 .family = NFPROTO_IPV4,
142 .match = owner_mt_v0,
143 .matchsize = sizeof(struct ipt_owner_info),
144 .checkentry = owner_mt_check_v0,
145 .hooks = (1 << NF_INET_LOCAL_OUT) |
146 (1 << NF_INET_POST_ROUTING),
147 .me = THIS_MODULE,
148 },
149 {
150 .name = "owner",
151 .revision = 0,
152 .family = NFPROTO_IPV6,
153 .match = owner_mt6_v0,
154 .matchsize = sizeof(struct ip6t_owner_info),
155 .checkentry = owner_mt6_check_v0,
156 .hooks = (1 << NF_INET_LOCAL_OUT) |
157 (1 << NF_INET_POST_ROUTING),
158 .me = THIS_MODULE,
159 },
160 {
161 .name = "owner",
162 .revision = 1,
163 .family = NFPROTO_UNSPEC,
164 .match = owner_mt,
165 .matchsize = sizeof(struct xt_owner_match_info),
166 .hooks = (1 << NF_INET_LOCAL_OUT) |
167 (1 << NF_INET_POST_ROUTING),
168 .me = THIS_MODULE,
169 },
170};
171
172static int __init owner_mt_init(void)
173{
174 return xt_register_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
175}
176
177static void __exit owner_mt_exit(void)
178{
179 xt_unregister_matches(owner_mt_reg, ARRAY_SIZE(owner_mt_reg));
180}
181
182module_init(owner_mt_init);
183module_exit(owner_mt_exit);
184MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
185MODULE_DESCRIPTION("Xtables: socket owner matching");
186MODULE_LICENSE("GPL");
187MODULE_ALIAS("ipt_owner");
188MODULE_ALIAS("ip6t_owner");