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 <linux/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/sysctl.h>
38 #include <linux/export.h>
39 #include <net/ip.h>
40 #include <net/arp.h>
41
42 /*
43 * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
44 */
45
46 static HLIST_HEAD(ax25_uid_list);
47 static DEFINE_RWLOCK(ax25_uid_lock);
48
49 int ax25_uid_policy;
50
51 EXPORT_SYMBOL(ax25_uid_policy);
52
ax25_findbyuid(kuid_t uid)53 ax25_uid_assoc *ax25_findbyuid(kuid_t uid)
54 {
55 ax25_uid_assoc *ax25_uid, *res = NULL;
56
57 read_lock(&ax25_uid_lock);
58 ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
59 if (uid_eq(ax25_uid->uid, uid)) {
60 ax25_uid_hold(ax25_uid);
61 res = ax25_uid;
62 break;
63 }
64 }
65 read_unlock(&ax25_uid_lock);
66
67 return res;
68 }
69
70 EXPORT_SYMBOL(ax25_findbyuid);
71
ax25_uid_ioctl(int cmd,struct sockaddr_ax25 * sax)72 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
73 {
74 ax25_uid_assoc *ax25_uid;
75 ax25_uid_assoc *user;
76 unsigned long res;
77
78 switch (cmd) {
79 case SIOCAX25GETUID:
80 res = -ENOENT;
81 read_lock(&ax25_uid_lock);
82 ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
83 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0) {
84 res = from_kuid_munged(current_user_ns(), ax25_uid->uid);
85 break;
86 }
87 }
88 read_unlock(&ax25_uid_lock);
89
90 return res;
91
92 case SIOCAX25ADDUID:
93 {
94 kuid_t sax25_kuid;
95 if (!capable(CAP_NET_ADMIN))
96 return -EPERM;
97 sax25_kuid = make_kuid(current_user_ns(), sax->sax25_uid);
98 if (!uid_valid(sax25_kuid))
99 return -EINVAL;
100 user = ax25_findbyuid(sax25_kuid);
101 if (user) {
102 ax25_uid_put(user);
103 return -EEXIST;
104 }
105 if (sax->sax25_uid == 0)
106 return -EINVAL;
107 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
108 return -ENOMEM;
109
110 refcount_set(&ax25_uid->refcount, 1);
111 ax25_uid->uid = sax25_kuid;
112 ax25_uid->call = sax->sax25_call;
113
114 write_lock(&ax25_uid_lock);
115 hlist_add_head(&ax25_uid->uid_node, &ax25_uid_list);
116 write_unlock(&ax25_uid_lock);
117
118 return 0;
119 }
120 case SIOCAX25DELUID:
121 if (!capable(CAP_NET_ADMIN))
122 return -EPERM;
123
124 ax25_uid = NULL;
125 write_lock(&ax25_uid_lock);
126 ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
127 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
128 break;
129 }
130 if (ax25_uid == NULL) {
131 write_unlock(&ax25_uid_lock);
132 return -ENOENT;
133 }
134 hlist_del_init(&ax25_uid->uid_node);
135 ax25_uid_put(ax25_uid);
136 write_unlock(&ax25_uid_lock);
137
138 return 0;
139
140 default:
141 return -EINVAL;
142 }
143
144 return -EINVAL; /*NOTREACHED */
145 }
146
147 #ifdef CONFIG_PROC_FS
148
ax25_uid_seq_start(struct seq_file * seq,loff_t * pos)149 static void *ax25_uid_seq_start(struct seq_file *seq, loff_t *pos)
150 __acquires(ax25_uid_lock)
151 {
152 read_lock(&ax25_uid_lock);
153 return seq_hlist_start_head(&ax25_uid_list, *pos);
154 }
155
ax25_uid_seq_next(struct seq_file * seq,void * v,loff_t * pos)156 static void *ax25_uid_seq_next(struct seq_file *seq, void *v, loff_t *pos)
157 {
158 return seq_hlist_next(v, &ax25_uid_list, pos);
159 }
160
ax25_uid_seq_stop(struct seq_file * seq,void * v)161 static void ax25_uid_seq_stop(struct seq_file *seq, void *v)
162 __releases(ax25_uid_lock)
163 {
164 read_unlock(&ax25_uid_lock);
165 }
166
ax25_uid_seq_show(struct seq_file * seq,void * v)167 static int ax25_uid_seq_show(struct seq_file *seq, void *v)
168 {
169 char buf[11];
170
171 if (v == SEQ_START_TOKEN)
172 seq_printf(seq, "Policy: %d\n", ax25_uid_policy);
173 else {
174 struct ax25_uid_assoc *pt;
175
176 pt = hlist_entry(v, struct ax25_uid_assoc, uid_node);
177 seq_printf(seq, "%6d %s\n",
178 from_kuid_munged(seq_user_ns(seq), pt->uid),
179 ax2asc(buf, &pt->call));
180 }
181 return 0;
182 }
183
184 const struct seq_operations ax25_uid_seqops = {
185 .start = ax25_uid_seq_start,
186 .next = ax25_uid_seq_next,
187 .stop = ax25_uid_seq_stop,
188 .show = ax25_uid_seq_show,
189 };
190 #endif
191
192 /*
193 * Free all memory associated with UID/Callsign structures.
194 */
ax25_uid_free(void)195 void __exit ax25_uid_free(void)
196 {
197 ax25_uid_assoc *ax25_uid;
198
199 write_lock(&ax25_uid_lock);
200 again:
201 ax25_uid_for_each(ax25_uid, &ax25_uid_list) {
202 hlist_del_init(&ax25_uid->uid_node);
203 ax25_uid_put(ax25_uid);
204 goto again;
205 }
206 write_unlock(&ax25_uid_lock);
207 }
208
