File: /usr/src/linux/net/ax25/ax25_uid.c
1 /*
2 * AX.25 release 037
3 *
4 * This code REQUIRES 2.1.15 or higher/ NET3.038
5 *
6 * This module:
7 * This module is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * History
13 * AX.25 036 Jonathan(G4KLX) Split from af_ax25.c.
14 */
15
16 #include <linux/errno.h>
17 #include <linux/types.h>
18 #include <linux/socket.h>
19 #include <linux/in.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/timer.h>
23 #include <linux/string.h>
24 #include <linux/sockios.h>
25 #include <linux/net.h>
26 #include <net/ax25.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <linux/if_arp.h>
30 #include <linux/skbuff.h>
31 #include <net/sock.h>
32 #include <asm/uaccess.h>
33 #include <asm/system.h>
34 #include <linux/fcntl.h>
35 #include <linux/mm.h>
36 #include <linux/interrupt.h>
37 #include <linux/notifier.h>
38 #include <linux/proc_fs.h>
39 #include <linux/stat.h>
40 #include <linux/netfilter.h>
41 #include <linux/sysctl.h>
42 #include <net/ip.h>
43 #include <net/arp.h>
44
45 /*
46 * Callsign/UID mapper. This is in kernel space for security on multi-amateur machines.
47 */
48
49 static ax25_uid_assoc *ax25_uid_list;
50
51 int ax25_uid_policy = 0;
52
53 ax25_address *ax25_findbyuid(uid_t uid)
54 {
55 ax25_uid_assoc *ax25_uid;
56
57 for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
58 if (ax25_uid->uid == uid)
59 return &ax25_uid->call;
60 }
61
62 return NULL;
63 }
64
65 int ax25_uid_ioctl(int cmd, struct sockaddr_ax25 *sax)
66 {
67 ax25_uid_assoc *s, *ax25_uid;
68 unsigned long flags;
69
70 switch (cmd) {
71 case SIOCAX25GETUID:
72 for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
73 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
74 return ax25_uid->uid;
75 }
76 return -ENOENT;
77
78 case SIOCAX25ADDUID:
79 if (!capable(CAP_NET_ADMIN))
80 return -EPERM;
81 if (ax25_findbyuid(sax->sax25_uid))
82 return -EEXIST;
83 if (sax->sax25_uid == 0)
84 return -EINVAL;
85 if ((ax25_uid = kmalloc(sizeof(*ax25_uid), GFP_KERNEL)) == NULL)
86 return -ENOMEM;
87 ax25_uid->uid = sax->sax25_uid;
88 ax25_uid->call = sax->sax25_call;
89 save_flags(flags); cli();
90 ax25_uid->next = ax25_uid_list;
91 ax25_uid_list = ax25_uid;
92 restore_flags(flags);
93 return 0;
94
95 case SIOCAX25DELUID:
96 if (!capable(CAP_NET_ADMIN))
97 return -EPERM;
98 for (ax25_uid = ax25_uid_list; ax25_uid != NULL; ax25_uid = ax25_uid->next) {
99 if (ax25cmp(&sax->sax25_call, &ax25_uid->call) == 0)
100 break;
101 }
102 if (ax25_uid == NULL)
103 return -ENOENT;
104 save_flags(flags); cli();
105 if ((s = ax25_uid_list) == ax25_uid) {
106 ax25_uid_list = s->next;
107 restore_flags(flags);
108 kfree(ax25_uid);
109 return 0;
110 }
111 while (s != NULL && s->next != NULL) {
112 if (s->next == ax25_uid) {
113 s->next = ax25_uid->next;
114 restore_flags(flags);
115 kfree(ax25_uid);
116 return 0;
117 }
118 s = s->next;
119 }
120 restore_flags(flags);
121 return -ENOENT;
122
123 default:
124 return -EINVAL;
125 }
126
127 return -EINVAL; /*NOTREACHED */
128 }
129
130 int ax25_uid_get_info(char *buffer, char **start, off_t offset, int length)
131 {
132 ax25_uid_assoc *pt;
133 int len = 0;
134 off_t pos = 0;
135 off_t begin = 0;
136
137 cli();
138
139 len += sprintf(buffer, "Policy: %d\n", ax25_uid_policy);
140
141 for (pt = ax25_uid_list; pt != NULL; pt = pt->next) {
142 len += sprintf(buffer + len, "%6d %s\n", pt->uid, ax2asc(&pt->call));
143
144 pos = begin + len;
145
146 if (pos < offset) {
147 len = 0;
148 begin = pos;
149 }
150
151 if (pos > offset + length)
152 break;
153 }
154
155 sti();
156
157 *start = buffer + (offset - begin);
158 len -= offset - begin;
159
160 if (len > length) len = length;
161
162 return len;
163 }
164
165 /*
166 * Free all memory associated with UID/Callsign structures.
167 */
168 void __exit ax25_uid_free(void)
169 {
170 ax25_uid_assoc *s, *ax25_uid = ax25_uid_list;
171
172 while (ax25_uid != NULL) {
173 s = ax25_uid;
174 ax25_uid = ax25_uid->next;
175
176 kfree(s);
177 }
178 }
179