[INET]: Generalise tcp_v4_lookup_listener
[linux-2.6] / 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/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 }