xref: /openbmc/linux/net/ax25/ax25_iface.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
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/config.h>
10 #include <linux/errno.h>
11 #include <linux/types.h>
12 #include <linux/socket.h>
13 #include <linux/in.h>
14 #include <linux/kernel.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 protocol_struct {
33 	struct protocol_struct *next;
34 	unsigned int pid;
35 	int (*func)(struct sk_buff *, ax25_cb *);
36 } *protocol_list = NULL;
37 static DEFINE_RWLOCK(protocol_list_lock);
38 
39 static struct linkfail_struct {
40 	struct linkfail_struct *next;
41 	void (*func)(ax25_cb *, int);
42 } *linkfail_list = NULL;
43 static DEFINE_SPINLOCK(linkfail_lock);
44 
45 static struct listen_struct {
46 	struct listen_struct *next;
47 	ax25_address  callsign;
48 	struct net_device *dev;
49 } *listen_list = NULL;
50 static DEFINE_SPINLOCK(listen_lock);
51 
52 int ax25_protocol_register(unsigned int pid,
53 	int (*func)(struct sk_buff *, ax25_cb *))
54 {
55 	struct protocol_struct *protocol;
56 
57 	if (pid == AX25_P_TEXT || pid == AX25_P_SEGMENT)
58 		return 0;
59 #ifdef CONFIG_INET
60 	if (pid == AX25_P_IP || pid == AX25_P_ARP)
61 		return 0;
62 #endif
63 	if ((protocol = kmalloc(sizeof(*protocol), GFP_ATOMIC)) == NULL)
64 		return 0;
65 
66 	protocol->pid  = pid;
67 	protocol->func = func;
68 
69 	write_lock(&protocol_list_lock);
70 	protocol->next = protocol_list;
71 	protocol_list  = protocol;
72 	write_unlock(&protocol_list_lock);
73 
74 	return 1;
75 }
76 
77 void ax25_protocol_release(unsigned int pid)
78 {
79 	struct protocol_struct *s, *protocol;
80 
81 	write_lock(&protocol_list_lock);
82 	protocol = protocol_list;
83 	if (protocol == NULL) {
84 		write_unlock(&protocol_list_lock);
85 		return;
86 	}
87 
88 	if (protocol->pid == pid) {
89 		protocol_list = protocol->next;
90 		write_unlock(&protocol_list_lock);
91 		kfree(protocol);
92 		return;
93 	}
94 
95 	while (protocol != NULL && protocol->next != NULL) {
96 		if (protocol->next->pid == pid) {
97 			s = protocol->next;
98 			protocol->next = protocol->next->next;
99 			write_unlock(&protocol_list_lock);
100 			kfree(s);
101 			return;
102 		}
103 
104 		protocol = protocol->next;
105 	}
106 	write_unlock(&protocol_list_lock);
107 }
108 
109 int ax25_linkfail_register(void (*func)(ax25_cb *, int))
110 {
111 	struct linkfail_struct *linkfail;
112 
113 	if ((linkfail = kmalloc(sizeof(*linkfail), GFP_ATOMIC)) == NULL)
114 		return 0;
115 
116 	linkfail->func = func;
117 
118 	spin_lock_bh(&linkfail_lock);
119 	linkfail->next = linkfail_list;
120 	linkfail_list  = linkfail;
121 	spin_unlock_bh(&linkfail_lock);
122 
123 	return 1;
124 }
125 
126 void ax25_linkfail_release(void (*func)(ax25_cb *, int))
127 {
128 	struct linkfail_struct *s, *linkfail;
129 
130 	spin_lock_bh(&linkfail_lock);
131 	linkfail = linkfail_list;
132 	if (linkfail == NULL) {
133 		spin_unlock_bh(&linkfail_lock);
134 		return;
135 	}
136 
137 	if (linkfail->func == func) {
138 		linkfail_list = linkfail->next;
139 		spin_unlock_bh(&linkfail_lock);
140 		kfree(linkfail);
141 		return;
142 	}
143 
144 	while (linkfail != NULL && linkfail->next != NULL) {
145 		if (linkfail->next->func == func) {
146 			s = linkfail->next;
147 			linkfail->next = linkfail->next->next;
148 			spin_unlock_bh(&linkfail_lock);
149 			kfree(s);
150 			return;
151 		}
152 
153 		linkfail = linkfail->next;
154 	}
155 	spin_unlock_bh(&linkfail_lock);
156 }
157 
158 int ax25_listen_register(ax25_address *callsign, struct net_device *dev)
159 {
160 	struct listen_struct *listen;
161 
162 	if (ax25_listen_mine(callsign, dev))
163 		return 0;
164 
165 	if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL)
166 		return 0;
167 
168 	listen->callsign = *callsign;
169 	listen->dev      = dev;
170 
171 	spin_lock_bh(&listen_lock);
172 	listen->next = listen_list;
173 	listen_list  = listen;
174 	spin_unlock_bh(&listen_lock);
175 
176 	return 1;
177 }
178 
179 void ax25_listen_release(ax25_address *callsign, struct net_device *dev)
180 {
181 	struct listen_struct *s, *listen;
182 
183 	spin_lock_bh(&listen_lock);
184 	listen = listen_list;
185 	if (listen == NULL) {
186 		spin_unlock_bh(&listen_lock);
187 		return;
188 	}
189 
190 	if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) {
191 		listen_list = listen->next;
192 		spin_unlock_bh(&listen_lock);
193 		kfree(listen);
194 		return;
195 	}
196 
197 	while (listen != NULL && listen->next != NULL) {
198 		if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) {
199 			s = listen->next;
200 			listen->next = listen->next->next;
201 			spin_unlock_bh(&listen_lock);
202 			kfree(s);
203 			return;
204 		}
205 
206 		listen = listen->next;
207 	}
208 	spin_unlock_bh(&listen_lock);
209 }
210 
211 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *)
212 {
213 	int (*res)(struct sk_buff *, ax25_cb *) = NULL;
214 	struct protocol_struct *protocol;
215 
216 	read_lock(&protocol_list_lock);
217 	for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
218 		if (protocol->pid == pid) {
219 			res = protocol->func;
220 			break;
221 		}
222 	read_unlock(&protocol_list_lock);
223 
224 	return res;
225 }
226 
227 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev)
228 {
229 	struct listen_struct *listen;
230 
231 	spin_lock_bh(&listen_lock);
232 	for (listen = listen_list; listen != NULL; listen = listen->next)
233 		if (ax25cmp(&listen->callsign, callsign) == 0 && (listen->dev == dev || listen->dev == NULL)) {
234 			spin_unlock_bh(&listen_lock);
235 			return 1;
236 	}
237 	spin_unlock_bh(&listen_lock);
238 
239 	return 0;
240 }
241 
242 void ax25_link_failed(ax25_cb *ax25, int reason)
243 {
244 	struct linkfail_struct *linkfail;
245 
246 	spin_lock_bh(&linkfail_lock);
247 	for (linkfail = linkfail_list; linkfail != NULL; linkfail = linkfail->next)
248 		(linkfail->func)(ax25, reason);
249 	spin_unlock_bh(&linkfail_lock);
250 }
251 
252 int ax25_protocol_is_registered(unsigned int pid)
253 {
254 	struct protocol_struct *protocol;
255 	int res = 0;
256 
257 	read_lock(&protocol_list_lock);
258 	for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
259 		if (protocol->pid == pid) {
260 			res = 1;
261 			break;
262 		}
263 	read_unlock(&protocol_list_lock);
264 
265 	return res;
266 }
267