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 }