Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* Kernel module to match various things tied to sockets associated with |
2 | locally generated outgoing packets. */ | |
3 | ||
4 | /* (C) 2000 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 <net/sock.h> | |
15 | ||
16 | #include <linux/netfilter_ipv4/ipt_owner.h> | |
17 | #include <linux/netfilter_ipv4/ip_tables.h> | |
18 | ||
19 | MODULE_LICENSE("GPL"); | |
20 | MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); | |
21 | MODULE_DESCRIPTION("iptables owner match"); | |
22 | ||
23 | static int | |
24 | match_comm(const struct sk_buff *skb, const char *comm) | |
25 | { | |
26 | struct task_struct *g, *p; | |
27 | struct files_struct *files; | |
28 | int i; | |
29 | ||
30 | read_lock(&tasklist_lock); | |
31 | do_each_thread(g, p) { | |
32 | if(strncmp(p->comm, comm, sizeof(p->comm))) | |
33 | continue; | |
34 | ||
35 | task_lock(p); | |
36 | files = p->files; | |
37 | if(files) { | |
38 | spin_lock(&files->file_lock); | |
39 | for (i=0; i < files->max_fds; i++) { | |
40 | if (fcheck_files(files, i) == | |
41 | skb->sk->sk_socket->file) { | |
42 | spin_unlock(&files->file_lock); | |
43 | task_unlock(p); | |
44 | read_unlock(&tasklist_lock); | |
45 | return 1; | |
46 | } | |
47 | } | |
48 | spin_unlock(&files->file_lock); | |
49 | } | |
50 | task_unlock(p); | |
51 | } while_each_thread(g, p); | |
52 | read_unlock(&tasklist_lock); | |
53 | return 0; | |
54 | } | |
55 | ||
56 | static int | |
57 | match_pid(const struct sk_buff *skb, pid_t pid) | |
58 | { | |
59 | struct task_struct *p; | |
60 | struct files_struct *files; | |
61 | int i; | |
62 | ||
63 | read_lock(&tasklist_lock); | |
64 | p = find_task_by_pid(pid); | |
65 | if (!p) | |
66 | goto out; | |
67 | task_lock(p); | |
68 | files = p->files; | |
69 | if(files) { | |
70 | spin_lock(&files->file_lock); | |
71 | for (i=0; i < files->max_fds; i++) { | |
72 | if (fcheck_files(files, i) == | |
73 | skb->sk->sk_socket->file) { | |
74 | spin_unlock(&files->file_lock); | |
75 | task_unlock(p); | |
76 | read_unlock(&tasklist_lock); | |
77 | return 1; | |
78 | } | |
79 | } | |
80 | spin_unlock(&files->file_lock); | |
81 | } | |
82 | task_unlock(p); | |
83 | out: | |
84 | read_unlock(&tasklist_lock); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static int | |
89 | match_sid(const struct sk_buff *skb, pid_t sid) | |
90 | { | |
91 | struct task_struct *g, *p; | |
92 | struct file *file = skb->sk->sk_socket->file; | |
93 | int i, found=0; | |
94 | ||
95 | read_lock(&tasklist_lock); | |
96 | do_each_thread(g, p) { | |
97 | struct files_struct *files; | |
98 | if (p->signal->session != sid) | |
99 | continue; | |
100 | ||
101 | task_lock(p); | |
102 | files = p->files; | |
103 | if (files) { | |
104 | spin_lock(&files->file_lock); | |
105 | for (i=0; i < files->max_fds; i++) { | |
106 | if (fcheck_files(files, i) == file) { | |
107 | found = 1; | |
108 | break; | |
109 | } | |
110 | } | |
111 | spin_unlock(&files->file_lock); | |
112 | } | |
113 | task_unlock(p); | |
114 | if (found) | |
115 | goto out; | |
116 | } while_each_thread(g, p); | |
117 | out: | |
118 | read_unlock(&tasklist_lock); | |
119 | ||
120 | return found; | |
121 | } | |
122 | ||
123 | static int | |
124 | match(const struct sk_buff *skb, | |
125 | const struct net_device *in, | |
126 | const struct net_device *out, | |
127 | const void *matchinfo, | |
128 | int offset, | |
129 | int *hotdrop) | |
130 | { | |
131 | const struct ipt_owner_info *info = matchinfo; | |
132 | ||
133 | if (!skb->sk || !skb->sk->sk_socket || !skb->sk->sk_socket->file) | |
134 | return 0; | |
135 | ||
136 | if(info->match & IPT_OWNER_UID) { | |
137 | if ((skb->sk->sk_socket->file->f_uid != info->uid) ^ | |
138 | !!(info->invert & IPT_OWNER_UID)) | |
139 | return 0; | |
140 | } | |
141 | ||
142 | if(info->match & IPT_OWNER_GID) { | |
143 | if ((skb->sk->sk_socket->file->f_gid != info->gid) ^ | |
144 | !!(info->invert & IPT_OWNER_GID)) | |
145 | return 0; | |
146 | } | |
147 | ||
148 | if(info->match & IPT_OWNER_PID) { | |
149 | if (!match_pid(skb, info->pid) ^ | |
150 | !!(info->invert & IPT_OWNER_PID)) | |
151 | return 0; | |
152 | } | |
153 | ||
154 | if(info->match & IPT_OWNER_SID) { | |
155 | if (!match_sid(skb, info->sid) ^ | |
156 | !!(info->invert & IPT_OWNER_SID)) | |
157 | return 0; | |
158 | } | |
159 | ||
160 | if(info->match & IPT_OWNER_COMM) { | |
161 | if (!match_comm(skb, info->comm) ^ | |
162 | !!(info->invert & IPT_OWNER_COMM)) | |
163 | return 0; | |
164 | } | |
165 | ||
166 | return 1; | |
167 | } | |
168 | ||
169 | static int | |
170 | checkentry(const char *tablename, | |
171 | const struct ipt_ip *ip, | |
172 | void *matchinfo, | |
173 | unsigned int matchsize, | |
174 | unsigned int hook_mask) | |
175 | { | |
176 | if (hook_mask | |
177 | & ~((1 << NF_IP_LOCAL_OUT) | (1 << NF_IP_POST_ROUTING))) { | |
178 | printk("ipt_owner: only valid for LOCAL_OUT or POST_ROUTING.\n"); | |
179 | return 0; | |
180 | } | |
181 | ||
182 | if (matchsize != IPT_ALIGN(sizeof(struct ipt_owner_info))) { | |
183 | printk("Matchsize %u != %Zu\n", matchsize, | |
184 | IPT_ALIGN(sizeof(struct ipt_owner_info))); | |
185 | return 0; | |
186 | } | |
187 | #ifdef CONFIG_SMP | |
188 | /* files->file_lock can not be used in a BH */ | |
189 | if (((struct ipt_owner_info *)matchinfo)->match | |
190 | & (IPT_OWNER_PID|IPT_OWNER_SID|IPT_OWNER_COMM)) { | |
191 | printk("ipt_owner: pid, sid and command matching is broken " | |
192 | "on SMP.\n"); | |
193 | return 0; | |
194 | } | |
195 | #endif | |
196 | return 1; | |
197 | } | |
198 | ||
199 | static struct ipt_match owner_match = { | |
200 | .name = "owner", | |
201 | .match = &match, | |
202 | .checkentry = &checkentry, | |
203 | .me = THIS_MODULE, | |
204 | }; | |
205 | ||
206 | static int __init init(void) | |
207 | { | |
208 | return ipt_register_match(&owner_match); | |
209 | } | |
210 | ||
211 | static void __exit fini(void) | |
212 | { | |
213 | ipt_unregister_match(&owner_match); | |
214 | } | |
215 | ||
216 | module_init(init); | |
217 | module_exit(fini); |