1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 */
9
10 #include <linux/capability.h>
11 #include <linux/errno.h>
12 #include <linux/types.h>
13 #include <linux/socket.h>
14 #include <linux/in.h>
15 #include <linux/kernel.h>
16 #include <linux/timer.h>
17 #include <linux/string.h>
18 #include <linux/sockios.h>
19 #include <linux/net.h>
20 #include <linux/spinlock.h>
21 #include <linux/slab.h>
22 #include <net/ax25.h>
23 #include <linux/inet.h>
24 #include <linux/netdevice.h>
25 #include <linux/if_arp.h>
26 #include <linux/skbuff.h>
27 #include <net/sock.h>
28 #include <asm/uaccess.h>
29 #include <linux/fcntl.h>
30 #include <linux/mm.h>
31 #include <linux/interrupt.h>
32 #include <linux/list.h>
33 #include <linux/notifier.h>
34 #include <linux/proc_fs.h>
35 #include <linux/seq_file.h>
36 #include <linux/stat.h>
37 #include <linux/netfilter.h>
38 #include <linux/sysctl.h>
39 #include <linux/export.h>
40 #include <net/ip.h>
41 #include <net/arp.h>
42
43 /*
44 * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
45 */
46
47 static HLIST_HEAD(ax25_uid_list);
48 static DEFINE_RWLOCK(ax25_uid_lock);
49
50 int ax25_uid_policy;
51
52 EXPORT_SYMBOL(ax25_uid_policy);
53
ax25_findbyuid(uid_t uid)54 ax25_uid_assoc *ax25_findbyuid(uid_t uid)
55 {
56 ax25_uid_assoc *ax25_uid, *res = NULL;
57 struct hlist_node *node;
58
59 read_lock(&ax25_uid_lock);
60 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
61 if (ax25_uid->uid == uid) {
62 ax25_uid_hold(ax25_uid);
63 res = ax25_uid;
64 break;
65 }
66 }
67 read_unlock(&ax25_uid_lock);
68
69 return res;
70 }
71
72 EXPORT_SYMBOL(ax25_findbyuid);
73
ax25_uid_ioctl(int cmd,struct sockaddr_ax25 * sax)74 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
75 {
76 ax25_uid_assoc *ax25_uid;
77 struct hlist_node *node;
78 ax25_uid_assoc *user;
79 unsigned long res;
80
81 switch (cmd) {
82 case SIOCAX25GETUID:
83 res = -ENOENT;
84 read_lock(&ax25_uid_lock);
85 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
86 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
87 res = ax25_uid->uid;
88 break;
89 }
90 }
91 read_unlock(&ax25_uid_lock);
92
93 return res;
94
95 case SIOCAX25ADDUID:
96 if (!capable(CAP_NET_ADMIN))
97 return -EPERM;
98 user = ax25_findbyuid(sax->sax25_uid);
99 if (user) {
100 ax25_uid_put(user);
101 return -EEXIST;
102 }
103 if (sax->sax25_uid == 0)
104 return -EINVAL;
105 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
106 return -ENOMEM;
107
108 atomic_set(&ax25_uid->refcount, 1);
109 ax25_uid->uid = sax->sax25_uid;
110 ax25_uid->call = sax->sax25_call;
111
112 write_lock(&ax25_uid_lock);
113 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
114 write_unlock(&ax25_uid_lock);
115
116 return 0;
117
118 case SIOCAX25DELUID:
119 if (!capable(CAP_NET_ADMIN))
120 return -EPERM;
121
122 ax25_uid = NULL;
123 write_lock(&ax25_uid_lock);
124 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
125 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
126 break;
127 }
128 if (ax25_uid == NULL) {
129 write_unlock(&ax25_uid_lock);
130 return -ENOENT;
131 }
132 hlist_del_init(&ax25_uid->uid_node);
133 ax25_uid_put(ax25_uid);
134 write_unlock(&ax25_uid_lock);
135
136 return 0;
137
138 default:
139 return -EINVAL;
140 }
141
142 return -EINVAL; /*NOTREACHED */
143 }
144
145 #ifdef CONFIG_PROC_FS
146
ax25_uid_seq_start(struct seq_file * seq,loff_t * pos)147 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
148 __acquires(ax25_uid_lock)
149 {
150 read_lock(&ax25_uid_lock);
151 return seq_hlist_start_head(&ax25_uid_list, *pos);
152 }
153
ax25_uid_seq_next(struct seq_file * seq,void * v,loff_t * pos)154 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
155 {
156 return seq_hlist_next(v, &ax25_uid_list, pos);
157 }
158
ax25_uid_seq_stop(struct seq_file * seq,void * v)159 static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
160 __releases(ax25_uid_lock)
161 {
162 read_unlock(&ax25_uid_lock);
163 }
164
ax25_uid_seq_show(struct seq_file * seq,void * v)165 static int ax25_uid_seq_show(struct seq_file *seq, void *v)
166 {
167 char buf[11];
168
169 if (v == SEQ_START_TOKEN)
170 seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
171 else {
172 struct ax25_uid_assoc *pt;
173
174 pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
175 seq_printf(seq, "%6d %s\n", pt->uid, ax2asc(buf, &pt->call));
176 }
177 return 0;
178 }
179
180 static const struct seq_operations ax25_uid_seqops = {
181 .start = ax25_uid_seq_start,
182 .next = ax25_uid_seq_next,
183 .stop = ax25_uid_seq_stop,
184 .show = ax25_uid_seq_show,
185 };
186
ax25_uid_info_open(struct inode * inode,struct file * file)187 static int ax25_uid_info_open(struct inode *inode, struct file *file)
188 {
189 return seq_open(file, &ax25_uid_seqops);
190 }
191
192 const struct file_operations ax25_uid_fops = {
193 .owner = THIS_MODULE,
194 .open = ax25_uid_info_open,
195 .read = seq_read,
196 .llseek = seq_lseek,
197 .release = seq_release,
198 };
199
200 #endif
201
202 /*
203 * Free all memory associated with UID/Callsign structures.
204 */
ax25_uid_free(void)205 void __exit ax25_uid_free(void)
206 {
207 ax25_uid_assoc *ax25_uid;
208 struct hlist_node *node;
209
210 write_lock(&ax25_uid_lock);
211 again:
212 ax25_uid_for_each(ax25_uid, node, &ax25_uid_list) {
213 hlist_del_init(&ax25_uid->uid_node);
214 ax25_uid_put(ax25_uid);
215 goto again;
216 }
217 write_unlock(&ax25_uid_lock);
218 }
219