1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/* Kernel module to match various things tied to sockets associated with
locally generated outgoing packets. */
/* (C) 2000-2001 Marc Boucher <marc@mbsi.ca>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/file.h>
#include <net/sock.h>
#include <linux/netfilter_ipv6/ip6t_owner.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("IP6 tables owner matching module");
MODULE_LICENSE("GPL");
static int
match_pid(const struct sk_buff *skb, pid_t pid)
{
struct task_struct *p;
struct files_struct *files;
int i;
read_lock(&tasklist_lock);
p = find_task_by_pid(pid);
if (!p)
goto out;
task_lock(p);
files = p->files;
if(files) {
spin_lock(&files->file_lock);
for (i=0; i < files->max_fds; i++) {
if (fcheck_files(files, i) == skb->sk->sk_socket->file) {
spin_unlock(&files->file_lock);
task_unlock(p);
read_unlock(&tasklist_lock);
return 1;
}
}
spin_unlock(&files->file_lock);
}
task_unlock(p);
out:
read_unlock(&tasklist_lock);
return 0;
}
static int
match_sid(const struct sk_buff *skb, pid_t sid)
{
struct task_struct *g, *p;
struct file *file = skb->sk->sk_socket->file;
int i, found=0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
struct files_struct *files;
if (p->signal->session != sid)
continue;
task_lock(p);
files = p->files;
if (files) {
spin_lock(&files->file_lock);
for (i=0; i < files->max_fds; i++) {
if (fcheck_files(files, i) == file) {
found = 1;
break;
}
}
spin_unlock(&files->file_lock);
}
task_unlock(p);
if (found)
goto out;
} while_each_thread(g, p);
out:
read_unlock(&tasklist_lock);
return found;
}
static int
match(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const void *matchinfo,
int offset,
unsigned int protoff,
int *hotdrop)
{
const struct ip6t_owner_info *info = matchinfo;
if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
return 0;
if(info->match & IP6T_OWNER_UID) {
if((skb->sk->sk_socket->file->f_uid != info->uid) ^
!!(info->invert & IP6T_OWNER_UID))
return 0;
}
if(info->match & IP6T_OWNER_GID) {
if((skb->sk->sk_socket->file->f_gid != info->gid) ^
!!(info->invert & IP6T_OWNER_GID))
return 0;
}
if(info->match & IP6T_OWNER_PID) {
if (!match_pid(skb, info->pid) ^
!!(info->invert & IP6T_OWNER_PID))
return 0;
}
if(info->match & IP6T_OWNER_SID) {
if (!match_sid(skb, info->sid) ^
!!(info->invert & IP6T_OWNER_SID))
return 0;
}
return 1;
}
static int
checkentry(const char *tablename,
const struct ip6t_ip6 *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
if (hook_mask
& ~((1 << NF_IP6_LOCAL_OUT) | (1 << NF_IP6_POST_ROUTING))) {
printk("ip6t_owner: only valid for LOCAL_OUT or POST_ROUTING.\n");
return 0;
}
if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_owner_info)))
return 0;
#ifdef CONFIG_SMP
/* files->file_lock can not be used in a BH */
if (((struct ip6t_owner_info *)matchinfo)->match
& (IP6T_OWNER_PID|IP6T_OWNER_SID)) {
printk("ip6t_owner: pid and sid matching is broken on SMP.\n");
return 0;
}
#endif
return 1;
}
static struct ip6t_match owner_match = {
.name = "owner",
.match = &match,
.checkentry = &checkentry,
.me = THIS_MODULE,
};
static int __init init(void)
{
return ip6t_register_match(&owner_match);
}
static void __exit fini(void)
{
ip6t_unregister_match(&owner_match);
}
module_init(init);
module_exit(fini);
|
