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 -ENOMEM;
 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 0;
 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 &&
 229                     (listen->dev == dev || listen->dev == NULL)) {
 230                         spin_unlock_bh(&listen_lock);
 231                         return 1;
 232         }
 233         spin_unlock_bh(&listen_lock);
 234
 235         return 0;
 236 }
 237
 238 void ax25_link_failed(ax25_cb *ax25, int reason)
 239 {
 240         struct linkfail_struct *linkfail;
 241
 242         spin_lock_bh(&linkfail_lock);
 243         for (linkfail = linkfail_list; linkfail != NULL; linkfail = linkfail->next)
 244                 (linkfail->func)(ax25, reason);
 245         spin_unlock_bh(&linkfail_lock);
 246 }
 247
 248 int ax25_protocol_is_registered(unsigned int pid)
 249 {
 250         struct ax25_protocol *protocol;
 251         int res = 0;
 252
 253         read_lock_bh(&protocol_list_lock);
 254         for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
 255                 if (protocol->pid == pid) {
 256                         res = 1;
 257                         break;
 258                 }
 259         read_unlock_bh(&protocol_list_lock);
 260
 261         return res;
 262 }