[AX.25]: Fix unchecked ax25_protocol_register uses.
[linux-2.6.git] / net / ax25 / ax25_iface.c
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 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/socket.h>
12 #include <linux/in.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/spinlock.h>
17 #include <linux/timer.h>
18 #include <linux/string.h>
19 #include <linux/sockios.h>
20 #include <linux/net.h>
21 #include <net/ax25.h>
22 #include <linux/inet.h>
23 #include <linux/netdevice.h>
24 #include <linux/skbuff.h>
25 #include <net/sock.h>
26 #include <asm/uaccess.h>
27 #include <asm/system.h>
28 #include <linux/fcntl.h>
29 #include <linux/mm.h>
30 #include <linux/interrupt.h>
31
32 static struct ax25_protocol *protocol_list;
33 static DEFINE_RWLOCK(protocol_list_lock);
34
35 static struct linkfail_struct {
36         struct linkfail_struct *next;
37         void (*func)(ax25_cb *, int);
38 } *linkfail_list = NULL;
39 static DEFINE_SPINLOCK(linkfail_lock);
40
41 static struct listen_struct {
42         struct listen_struct *next;
43         ax25_address  callsign;
44         struct net_device *dev;
45 } *listen_list = NULL;
46 static DEFINE_SPINLOCK(listen_lock);
47
48 /*
49  * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT,
50  * AX25_P_IP or AX25_P_ARP ...
51  */
52 void ax25_register_pid(struct ax25_protocol *ap)
53 {
54         write_lock_bh(&protocol_list_lock);
55         ap->next = protocol_list;
56         protocol_list = ap;
57         write_unlock_bh(&protocol_list_lock);
58 }
59
60 EXPORT_SYMBOL_GPL(ax25_register_pid);
61
62 void ax25_protocol_release(unsigned int pid)
63 {
64         struct ax25_protocol *s, *protocol;
65
66         write_lock_bh(&protocol_list_lock);
67         protocol = protocol_list;
68         if (protocol == NULL) {
69                 write_unlock_bh(&protocol_list_lock);
70                 return;
71         }
72
73         if (protocol->pid == pid) {
74                 protocol_list = protocol->next;
75                 write_unlock_bh(&protocol_list_lock);
76                 kfree(protocol);
77                 return;
78         }
79
80         while (protocol != NULL && protocol->next != NULL) {
81                 if (protocol->next->pid == pid) {
82                         s = protocol->next;
83                         protocol->next = protocol->next->next;
84                         write_unlock_bh(&protocol_list_lock);
85                         kfree(s);
86                         return;
87                 }
88
89                 protocol = protocol->next;
90         }
91         write_unlock_bh(&protocol_list_lock);
92 }
93
94 EXPORT_SYMBOL(ax25_protocol_release);
95
96 int ax25_linkfail_register(void (*func)(ax25_cb *, int))
97 {
98         struct linkfail_struct *linkfail;
99
100         if ((linkfail = kmalloc(sizeof(*linkfail), GFP_ATOMIC)) == NULL)
101                 return 0;
102
103         linkfail->func = func;
104
105         spin_lock_bh(&linkfail_lock);
106         linkfail->next = linkfail_list;
107         linkfail_list  = linkfail;
108         spin_unlock_bh(&linkfail_lock);
109
110         return 1;
111 }
112
113 EXPORT_SYMBOL(ax25_linkfail_register);
114
115 void ax25_linkfail_release(void (*func)(ax25_cb *, int))
116 {
117         struct linkfail_struct *s, *linkfail;
118
119         spin_lock_bh(&linkfail_lock);
120         linkfail = linkfail_list;
121         if (linkfail == NULL) {
122                 spin_unlock_bh(&linkfail_lock);
123                 return;
124         }
125
126         if (linkfail->func == func) {
127                 linkfail_list = linkfail->next;
128                 spin_unlock_bh(&linkfail_lock);
129                 kfree(linkfail);
130                 return;
131         }
132
133         while (linkfail != NULL && linkfail->next != NULL) {
134                 if (linkfail->next->func == func) {
135                         s = linkfail->next;
136                         linkfail->next = linkfail->next->next;
137                         spin_unlock_bh(&linkfail_lock);
138                         kfree(s);
139                         return;
140                 }
141
142                 linkfail = linkfail->next;
143         }
144         spin_unlock_bh(&linkfail_lock);
145 }
146
147 EXPORT_SYMBOL(ax25_linkfail_release);
148
149 int ax25_listen_register(ax25_address *callsign, struct net_device *dev)
150 {
151         struct listen_struct *listen;
152
153         if (ax25_listen_mine(callsign, dev))
154                 return 0;
155
156         if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL)
157                 return 0;
158
159         listen->callsign = *callsign;
160         listen->dev      = dev;
161
162         spin_lock_bh(&listen_lock);
163         listen->next = listen_list;
164         listen_list  = listen;
165         spin_unlock_bh(&listen_lock);
166
167         return 1;
168 }
169
170 EXPORT_SYMBOL(ax25_listen_register);
171
172 void ax25_listen_release(ax25_address *callsign, struct net_device *dev)
173 {
174         struct listen_struct *s, *listen;
175
176         spin_lock_bh(&listen_lock);
177         listen = listen_list;
178         if (listen == NULL) {
179                 spin_unlock_bh(&listen_lock);
180                 return;
181         }
182
183         if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) {
184                 listen_list = listen->next;
185                 spin_unlock_bh(&listen_lock);
186                 kfree(listen);
187                 return;
188         }
189
190         while (listen != NULL && listen->next != NULL) {
191                 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) {
192                         s = listen->next;
193                         listen->next = listen->next->next;
194                         spin_unlock_bh(&listen_lock);
195                         kfree(s);
196                         return;
197                 }
198
199                 listen = listen->next;
200         }
201         spin_unlock_bh(&listen_lock);
202 }
203
204 EXPORT_SYMBOL(ax25_listen_release);
205
206 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *)
207 {
208         int (*res)(struct sk_buff *, ax25_cb *) = NULL;
209         struct ax25_protocol *protocol;
210
211         read_lock(&protocol_list_lock);
212         for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
213                 if (protocol->pid == pid) {
214                         res = protocol->func;
215                         break;
216                 }
217         read_unlock(&protocol_list_lock);
218
219         return res;
220 }
221
222 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev)
223 {
224         struct listen_struct *listen;
225
226         spin_lock_bh(&listen_lock);
227         for (listen = listen_list; listen != NULL; listen = listen->next)
228                 if (ax25cmp(&listen->callsign, callsign) == 0 && (listen->dev == dev || listen->dev == NULL)) {
229                         spin_unlock_bh(&listen_lock);
230                         return 1;
231         }
232         spin_unlock_bh(&listen_lock);
233
234         return 0;
235 }
236
237 void ax25_link_failed(ax25_cb *ax25, int reason)
238 {
239         struct linkfail_struct *linkfail;
240
241         spin_lock_bh(&linkfail_lock);
242         for (linkfail = linkfail_list; linkfail != NULL; linkfail = linkfail->next)
243                 (linkfail->func)(ax25, reason);
244         spin_unlock_bh(&linkfail_lock);
245 }
246
247 int ax25_protocol_is_registered(unsigned int pid)
248 {
249         struct ax25_protocol *protocol;
250         int res = 0;
251
252         read_lock_bh(&protocol_list_lock);
253         for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
254                 if (protocol->pid == pid) {
255                         res = 1;
256                         break;
257                 }
258         read_unlock_bh(&protocol_list_lock);
259
260         return res;
261 }