net/ax25/ax25_dev.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/sched.h>
  15 #include <linux/timer.h>
  16 #include <linux/string.h>
  17 #include <linux/sockios.h>
  18 #include <linux/net.h>
  19 #include <linux/spinlock.h>
  20 #include <net/ax25.h>
  21 #include <linux/inet.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/if_arp.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 #include <linux/init.h>
  32
  33 ax25_dev *ax25_dev_list;
  34 DEFINE_SPINLOCK(ax25_dev_lock);
  35
  36 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
  37 {
  38         ax25_dev *ax25_dev, *res = NULL;
  39
  40         spin_lock_bh(&ax25_dev_lock);
  41         for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
  42                 if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
  43                         res = ax25_dev;
  44                 }
  45         spin_unlock_bh(&ax25_dev_lock);
  46
  47         return res;
  48 }
  49
  50 /*
  51  *      This is called when an interface is brought up. These are
  52  *      reasonable defaults.
  53  */
  54 void ax25_dev_device_up(struct net_device *dev)
  55 {
  56         ax25_dev *ax25_dev;
  57
  58         if ((ax25_dev = kmalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
  59                 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
  60                 return;
  61         }
  62
  63         ax25_unregister_sysctl();
  64
  65         memset(ax25_dev, 0x00, sizeof(*ax25_dev));
  66
  67         dev->ax25_ptr     = ax25_dev;
  68         ax25_dev->dev     = dev;
  69         dev_hold(dev);
  70         ax25_dev->forward = NULL;
  71
  72         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  73         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  74         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  75         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  76         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  77         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  78         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  79         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  80         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  81         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  82         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  83         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  84         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  85         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  86
  87 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  88         init_timer(&ax25_dev->dama.slave_timer);
  89 #endif
  90
  91         spin_lock_bh(&ax25_dev_lock);
  92         ax25_dev->next = ax25_dev_list;
  93         ax25_dev_list  = ax25_dev;
  94         spin_unlock_bh(&ax25_dev_lock);
  95
  96         ax25_register_sysctl();
  97 }
  98
  99 void ax25_dev_device_down(struct net_device *dev)
 100 {
 101         ax25_dev *s, *ax25_dev;
 102
 103         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 104                 return;
 105
 106         ax25_unregister_sysctl();
 107
 108         spin_lock_bh(&ax25_dev_lock);
 109
 110 #ifdef CONFIG_AX25_DAMA_SLAVE
 111         ax25_ds_del_timer(ax25_dev);
 112 #endif
 113
 114         /*
 115          *      Remove any packet forwarding that points to this device.
 116          */
 117         for (s = ax25_dev_list; s != NULL; s = s->next)
 118                 if (s->forward == dev)
 119                         s->forward = NULL;
 120
 121         if ((s = ax25_dev_list) == ax25_dev) {
 122                 ax25_dev_list = s->next;
 123                 spin_unlock_bh(&ax25_dev_lock);
 124                 dev_put(dev);
 125                 kfree(ax25_dev);
 126                 ax25_register_sysctl();
 127                 return;
 128         }
 129
 130         while (s != NULL && s->next != NULL) {
 131                 if (s->next == ax25_dev) {
 132                         s->next = ax25_dev->next;
 133                         spin_unlock_bh(&ax25_dev_lock);
 134                         dev_put(dev);
 135                         kfree(ax25_dev);
 136                         ax25_register_sysctl();
 137                         return;
 138                 }
 139
 140                 s = s->next;
 141         }
 142         spin_unlock_bh(&ax25_dev_lock);
 143         dev->ax25_ptr = NULL;
 144
 145         ax25_register_sysctl();
 146 }
 147
 148 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 149 {
 150         ax25_dev *ax25_dev, *fwd_dev;
 151
 152         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 153                 return -EINVAL;
 154
 155         switch (cmd) {
 156         case SIOCAX25ADDFWD:
 157                 if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
 158                         return -EINVAL;
 159                 if (ax25_dev->forward != NULL)
 160                         return -EINVAL;
 161                 ax25_dev->forward = fwd_dev->dev;
 162                 break;
 163
 164         case SIOCAX25DELFWD:
 165                 if (ax25_dev->forward == NULL)
 166                         return -EINVAL;
 167                 ax25_dev->forward = NULL;
 168                 break;
 169
 170         default:
 171                 return -EINVAL;
 172         }
 173
 174         return 0;
 175 }
 176
 177 struct net_device *ax25_fwd_dev(struct net_device *dev)
 178 {
 179         ax25_dev *ax25_dev;
 180
 181         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 182                 return dev;
 183
 184         if (ax25_dev->forward == NULL)
 185                 return dev;
 186
 187         return ax25_dev->forward;
 188 }
 189
 190 /*
 191  *      Free all memory associated with device structures.
 192  */
 193 void __exit ax25_dev_free(void)
 194 {
 195         ax25_dev *s, *ax25_dev;
 196
 197         spin_lock_bh(&ax25_dev_lock);
 198         ax25_dev = ax25_dev_list;
 199         while (ax25_dev != NULL) {
 200                 s        = ax25_dev;
 201                 dev_put(ax25_dev->dev);
 202                 ax25_dev = ax25_dev->next;
 203                 kfree(s);
 204         }
 205         ax25_dev_list = NULL;
 206         spin_unlock_bh(&ax25_dev_lock);
 207 }