[S390] cio/ipl: Clean interface between cio and ipl code.
[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/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/spinlock.h>
16 #include <linux/timer.h>
17 #include <linux/string.h>
18 #include <linux/sockios.h>
19 #include <linux/net.h>
20 #include <net/ax25.h>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <linux/skbuff.h>
24 #include <net/sock.h>
25 #include <asm/uaccess.h>
26 #include <asm/system.h>
27 #include <linux/fcntl.h>
28 #include <linux/mm.h>
29 #include <linux/interrupt.h>
30
31 static struct ax25_protocol *protocol_list;
32 static DEFINE_RWLOCK(protocol_list_lock);
33
34 static HLIST_HEAD(ax25_linkfail_list);
35 static DEFINE_SPINLOCK(linkfail_lock);
36
37 static struct listen_struct {
38         struct listen_struct *next;
39         ax25_address  callsign;
40         struct net_device *dev;
41 } *listen_list = NULL;
42 static DEFINE_SPINLOCK(listen_lock);
43
44 /*
45  * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT,
46  * AX25_P_IP or AX25_P_ARP ...
47  */
48 void ax25_register_pid(struct ax25_protocol *ap)
49 {
50         write_lock_bh(&protocol_list_lock);
51         ap->next = protocol_list;
52         protocol_list = ap;
53         write_unlock_bh(&protocol_list_lock);
54 }
55
56 EXPORT_SYMBOL_GPL(ax25_register_pid);
57
58 void ax25_protocol_release(unsigned int pid)
59 {
60         struct ax25_protocol *s, *protocol;
61
62         write_lock_bh(&protocol_list_lock);
63         protocol = protocol_list;
64         if (protocol == NULL) {
65                 write_unlock_bh(&protocol_list_lock);
66                 return;
67         }
68
69         if (protocol->pid == pid) {
70                 protocol_list = protocol->next;
71                 write_unlock_bh(&protocol_list_lock);
72                 kfree(protocol);
73                 return;
74         }
75
76         while (protocol != NULL && protocol->next != NULL) {
77                 if (protocol->next->pid == pid) {
78                         s = protocol->next;
79                         protocol->next = protocol->next->next;
80                         write_unlock_bh(&protocol_list_lock);
81                         kfree(s);
82                         return;
83                 }
84
85                 protocol = protocol->next;
86         }
87         write_unlock_bh(&protocol_list_lock);
88 }
89
90 EXPORT_SYMBOL(ax25_protocol_release);
91
92 void ax25_linkfail_register(struct ax25_linkfail *lf)
93 {
94         spin_lock_bh(&linkfail_lock);
95         hlist_add_head(&lf->lf_node, &ax25_linkfail_list);
96         spin_unlock_bh(&linkfail_lock);
97 }
98
99 EXPORT_SYMBOL(ax25_linkfail_register);
100
101 void ax25_linkfail_release(struct ax25_linkfail *lf)
102 {
103         spin_lock_bh(&linkfail_lock);
104         hlist_del_init(&lf->lf_node);
105         spin_unlock_bh(&linkfail_lock);
106 }
107
108 EXPORT_SYMBOL(ax25_linkfail_release);
109
110 int ax25_listen_register(ax25_address *callsign, struct net_device *dev)
111 {
112         struct listen_struct *listen;
113
114         if (ax25_listen_mine(callsign, dev))
115                 return 0;
116
117         if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL)
118                 return -ENOMEM;
119
120         listen->callsign = *callsign;
121         listen->dev      = dev;
122
123         spin_lock_bh(&listen_lock);
124         listen->next = listen_list;
125         listen_list  = listen;
126         spin_unlock_bh(&listen_lock);
127
128         return 0;
129 }
130
131 EXPORT_SYMBOL(ax25_listen_register);
132
133 void ax25_listen_release(ax25_address *callsign, struct net_device *dev)
134 {
135         struct listen_struct *s, *listen;
136
137         spin_lock_bh(&listen_lock);
138         listen = listen_list;
139         if (listen == NULL) {
140                 spin_unlock_bh(&listen_lock);
141                 return;
142         }
143
144         if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) {
145                 listen_list = listen->next;
146                 spin_unlock_bh(&listen_lock);
147                 kfree(listen);
148                 return;
149         }
150
151         while (listen != NULL && listen->next != NULL) {
152                 if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) {
153                         s = listen->next;
154                         listen->next = listen->next->next;
155                         spin_unlock_bh(&listen_lock);
156                         kfree(s);
157                         return;
158                 }
159
160                 listen = listen->next;
161         }
162         spin_unlock_bh(&listen_lock);
163 }
164
165 EXPORT_SYMBOL(ax25_listen_release);
166
167 int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *)
168 {
169         int (*res)(struct sk_buff *, ax25_cb *) = NULL;
170         struct ax25_protocol *protocol;
171
172         read_lock(&protocol_list_lock);
173         for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
174                 if (protocol->pid == pid) {
175                         res = protocol->func;
176                         break;
177                 }
178         read_unlock(&protocol_list_lock);
179
180         return res;
181 }
182
183 int ax25_listen_mine(ax25_address *callsign, struct net_device *dev)
184 {
185         struct listen_struct *listen;
186
187         spin_lock_bh(&listen_lock);
188         for (listen = listen_list; listen != NULL; listen = listen->next)
189                 if (ax25cmp(&listen->callsign, callsign) == 0 &&
190                     (listen->dev == dev || listen->dev == NULL)) {
191                         spin_unlock_bh(&listen_lock);
192                         return 1;
193         }
194         spin_unlock_bh(&listen_lock);
195
196         return 0;
197 }
198
199 void ax25_link_failed(ax25_cb *ax25, int reason)
200 {
201         struct ax25_linkfail *lf;
202         struct hlist_node *node;
203
204         spin_lock_bh(&linkfail_lock);
205         hlist_for_each_entry(lf, node, &ax25_linkfail_list, lf_node)
206                 lf->func(ax25, reason);
207         spin_unlock_bh(&linkfail_lock);
208 }
209
210 int ax25_protocol_is_registered(unsigned int pid)
211 {
212         struct ax25_protocol *protocol;
213         int res = 0;
214
215         read_lock_bh(&protocol_list_lock);
216         for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
217                 if (protocol->pid == pid) {
218                         res = 1;
219                         break;
220                 }
221         read_unlock_bh(&protocol_list_lock);
222
223         return res;
224 }