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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/* Kernel module to match various things tied to sockets associated with
locally generated outgoing packets. */
/* (C) 2000 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_ipv4/ipt_owner.h>
#include <linux/netfilter_ipv4/ip_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
MODULE_DESCRIPTION("iptables owner match");
static int
match_comm(const struct sk_buff *skb, const char *comm)
{
struct task_struct *g, *p;
struct files_struct *files;
int i;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if(strncmp(p->comm, comm, sizeof(p->comm)))
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) ==
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);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
return 0;
}
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,
int *hotdrop)
{
const struct ipt_owner_info *info = matchinfo;
if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
return 0;
if(info->match & IPT_OWNER_UID) {
if ((skb->sk->sk_socket->file->f_uid != info->uid) ^
!!(info->invert & IPT_OWNER_UID))
return 0;
}
if(info->match & IPT_OWNER_GID) {
if ((skb->sk->sk_socket->file->f_gid != info->gid) ^
!!(info->invert & IPT_OWNER_GID))
return 0;
}
if(info->match & IPT_OWNER_PID) {
if (!match_pid(skb, info->pid) ^
!!(info->invert & IPT_OWNER_PID))
return 0;
}
if(info->match & IPT_OWNER_SID) {
if (!match_sid(skb, info->sid) ^
!!(info->invert & IPT_OWNER_SID))
return 0;
}
if(info->match & IPT_OWNER_COMM) {
if (!match_comm(skb, info->comm) ^
!!(info->invert & IPT_OWNER_COMM))
return 0;
}
return 1;
}
static int
checkentry(const char *tablename,
const struct ipt_ip *ip,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
if (hook_mask
& ~((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_POST_ROUTING))) {
printk("ipt_owner: only valid for LOCAL_OUT or POST_ROUTING.\n");
return 0;
}
if (matchsize != IPT_ALIGN(sizeof(struct ipt_owner_info))) {
printk("Matchsize %u != %Zu\n", matchsize,
IPT_ALIGN(sizeof(struct ipt_owner_info)));
return 0;
}
#ifdef CONFIG_SMP
/* files->file_lock can not be used in a BH */
if (((struct ipt_owner_info *)matchinfo)->match
& (IPT_OWNER_PID|IPT_OWNER_SID|IPT_OWNER_COMM)) {
printk("ipt_owner: pid, sid and command matching is broken "
"on SMP.\n");
return 0;
}
#endif
return 1;
}
static struct ipt_match owner_match = {
.name = "owner",
.match = &match,
.checkentry = &checkentry,
.me = THIS_MODULE,
};
static int __init init(void)
{
return ipt_register_match(&owner_match);
}
static void __exit fini(void)
{
ipt_unregister_match(&owner_match);
}
module_init(init);
module_exit(fini);
|
