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 
ax25_findbyuid(uid_t uid)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 
ax25_uid_ioctl(int cmd,struct sockaddr_ax25 * sax)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 
ax25_uid_get_info(char * buffer,char ** start,off_t offset,int length)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  */
ax25_uid_free(void)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