/net/ipv4/netfilter/ipt_owner.c
C | 204 lines | 173 code | 26 blank | 5 comment | 33 complexity | b41117c322034207a4f51ccc0678d1de MD5 | raw file
Possible License(s): CC-BY-SA-3.0, GPL-2.0, LGPL-2.0, AGPL-1.0
1/* Kernel module to match various things tied to sockets associated with
2 locally generated outgoing packets.
3
4 Copyright (C) 2000 Marc Boucher
5 */
6#include <linux/module.h>
7#include <linux/skbuff.h>
8#include <linux/file.h>
9#include <net/sock.h>
10
11#include <linux/netfilter_ipv4/ipt_owner.h>
12#include <linux/netfilter_ipv4/ip_tables.h>
13
14MODULE_LICENSE("GPL");
15MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
16MODULE_DESCRIPTION("iptables owner match");
17
18static int
19match_comm(const struct sk_buff *skb, const char *comm)
20{
21 struct task_struct *g, *p;
22 struct files_struct *files;
23 int i;
24
25 read_lock(&tasklist_lock);
26 do_each_thread(g, p) {
27 if(strncmp(p->comm, comm, sizeof(p->comm)))
28 continue;
29
30 task_lock(p);
31 files = p->files;
32 if(files) {
33 spin_lock(&files->file_lock);
34 for (i=0; i < files->max_fds; i++) {
35 if (fcheck_files(files, i) ==
36 skb->sk->sk_socket->file) {
37 spin_unlock(&files->file_lock);
38 task_unlock(p);
39 read_unlock(&tasklist_lock);
40 return 1;
41 }
42 }
43 spin_unlock(&files->file_lock);
44 }
45 task_unlock(p);
46 } while_each_thread(g, p);
47 read_unlock(&tasklist_lock);
48 return 0;
49}
50
51static int
52match_pid(const struct sk_buff *skb, pid_t pid)
53{
54 struct task_struct *p;
55 struct files_struct *files;
56 int i;
57
58 read_lock(&tasklist_lock);
59 p = find_task_by_pid(pid);
60 if (!p)
61 goto out;
62 task_lock(p);
63 files = p->files;
64 if(files) {
65 spin_lock(&files->file_lock);
66 for (i=0; i < files->max_fds; i++) {
67 if (fcheck_files(files, i) ==
68 skb->sk->sk_socket->file) {
69 spin_unlock(&files->file_lock);
70 task_unlock(p);
71 read_unlock(&tasklist_lock);
72 return 1;
73 }
74 }
75 spin_unlock(&files->file_lock);
76 }
77 task_unlock(p);
78out:
79 read_unlock(&tasklist_lock);
80 return 0;
81}
82
83static int
84match_sid(const struct sk_buff *skb, pid_t sid)
85{
86 struct task_struct *g, *p;
87 struct file *file = skb->sk->sk_socket->file;
88 int i, found=0;
89
90 read_lock(&tasklist_lock);
91 do_each_thread(g, p) {
92 struct files_struct *files;
93 if (p->session != sid)
94 continue;
95
96 task_lock(p);
97 files = p->files;
98 if (files) {
99 spin_lock(&files->file_lock);
100 for (i=0; i < files->max_fds; i++) {
101 if (fcheck_files(files, i) == file) {
102 found = 1;
103 break;
104 }
105 }
106 spin_unlock(&files->file_lock);
107 }
108 task_unlock(p);
109 if (found)
110 goto out;
111 } while_each_thread(g, p);
112out:
113 read_unlock(&tasklist_lock);
114
115 return found;
116}
117
118static int
119match(const struct sk_buff *skb,
120 const struct net_device *in,
121 const struct net_device *out,
122 const void *matchinfo,
123 int offset,
124 int *hotdrop)
125{
126 const struct ipt_owner_info *info = matchinfo;
127
128 if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file)
129 return 0;
130
131 if(info->match & IPT_OWNER_UID) {
132 if ((skb->sk->sk_socket->file->f_uid != info->uid) ^
133 !!(info->invert & IPT_OWNER_UID))
134 return 0;
135 }
136
137 if(info->match & IPT_OWNER_GID) {
138 if ((skb->sk->sk_socket->file->f_gid != info->gid) ^
139 !!(info->invert & IPT_OWNER_GID))
140 return 0;
141 }
142
143 if(info->match & IPT_OWNER_PID) {
144 if (!match_pid(skb, info->pid) ^
145 !!(info->invert & IPT_OWNER_PID))
146 return 0;
147 }
148
149 if(info->match & IPT_OWNER_SID) {
150 if (!match_sid(skb, info->sid) ^
151 !!(info->invert & IPT_OWNER_SID))
152 return 0;
153 }
154
155 if(info->match & IPT_OWNER_COMM) {
156 if (!match_comm(skb, info->comm) ^
157 !!(info->invert & IPT_OWNER_COMM))
158 return 0;
159 }
160
161 return 1;
162}
163
164static int
165checkentry(const char *tablename,
166 const struct ipt_ip *ip,
167 void *matchinfo,
168 unsigned int matchsize,
169 unsigned int hook_mask)
170{
171 if (hook_mask
172 & ~((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_POST_ROUTING))) {
173 printk("ipt_owner: only valid for LOCAL_OUT or POST_ROUTING.\n");
174 return 0;
175 }
176
177 if (matchsize != IPT_ALIGN(sizeof(struct ipt_owner_info))) {
178 printk("Matchsize %u != %Zu\n", matchsize,
179 IPT_ALIGN(sizeof(struct ipt_owner_info)));
180 return 0;
181 }
182
183 return 1;
184}
185
186static struct ipt_match owner_match = {
187 .name = "owner",
188 .match = &match,
189 .checkentry = &checkentry,
190 .me = THIS_MODULE,
191};
192
193static int __init init(void)
194{
195 return ipt_register_match(&owner_match);
196}
197
198static void __exit fini(void)
199{
200 ipt_unregister_match(&owner_match);
201}
202
203module_init(init);
204module_exit(fini);