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/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/timer.h>
  17 #include <linux/string.h>
  18 #include <linux/sockios.h>
  19 #include <linux/net.h>
  20 #include <linux/spinlock.h>
  21 #include <net/ax25.h>
  22 #include <linux/inet.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/if_arp.h>
  25 #include <linux/skbuff.h>
  26 #include <net/sock.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/system.h>
  29 #include <linux/fcntl.h>
  30 #include <linux/mm.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/init.h>
  33
  34 ax25_dev *ax25_dev_list;
  35 DEFINE_SPINLOCK(ax25_dev_lock);
  36
  37 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
  38 {
  39         ax25_dev *ax25_dev, *res = NULL;
  40
  41         spin_lock_bh(&ax25_dev_lock);
  42         for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
  43                 if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
  44                         res = ax25_dev;
  45                 }
  46         spin_unlock_bh(&ax25_dev_lock);
  47
  48         return res;
  49 }
  50
  51 /*
  52  *      This is called when an interface is brought up. These are
  53  *      reasonable defaults.
  54  */
  55 void ax25_dev_device_up(struct net_device *dev)
  56 {
  57         ax25_dev *ax25_dev;
  58
  59         if ((ax25_dev = kmalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
  60                 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
  61                 return;
  62         }
  63
  64         ax25_unregister_sysctl();
  65
  66         memset(ax25_dev, 0x00, sizeof(*ax25_dev));
  67
  68         dev->ax25_ptr     = ax25_dev;
  69         ax25_dev->dev     = dev;
  70         dev_hold(dev);
  71         ax25_dev->forward = NULL;
  72
  73         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  74         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  75         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  76         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  77         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  78         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  79         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  80         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  81         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  82         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  83         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  84         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  85         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  86         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  87
  88 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  89         init_timer(&ax25_dev->dama.slave_timer);
  90 #endif
  91
  92         spin_lock_bh(&ax25_dev_lock);
  93         ax25_dev->next = ax25_dev_list;
  94         ax25_dev_list  = ax25_dev;
  95         spin_unlock_bh(&ax25_dev_lock);
  96
  97         ax25_register_sysctl();
  98 }
  99
 100 void ax25_dev_device_down(struct net_device *dev)
 101 {
 102         ax25_dev *s, *ax25_dev;
 103
 104         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 105                 return;
 106
 107         ax25_unregister_sysctl();
 108
 109         spin_lock_bh(&ax25_dev_lock);
 110
 111 #ifdef CONFIG_AX25_DAMA_SLAVE
 112         ax25_ds_del_timer(ax25_dev);
 113 #endif
 114
 115         /*
 116          *      Remove any packet forwarding that points to this device.
 117          */
 118         for (s = ax25_dev_list; s != NULL; s = s->next)
 119                 if (s->forward == dev)
 120                         s->forward = NULL;
 121
 122         if ((s = ax25_dev_list) == ax25_dev) {
 123                 ax25_dev_list = s->next;
 124                 spin_unlock_bh(&ax25_dev_lock);
 125                 dev_put(dev);
 126                 kfree(ax25_dev);
 127                 ax25_register_sysctl();
 128                 return;
 129         }
 130
 131         while (s != NULL && s->next != NULL) {
 132                 if (s->next == ax25_dev) {
 133                         s->next = ax25_dev->next;
 134                         spin_unlock_bh(&ax25_dev_lock);
 135                         dev_put(dev);
 136                         kfree(ax25_dev);
 137                         ax25_register_sysctl();
 138                         return;
 139                 }
 140
 141                 s = s->next;
 142         }
 143         spin_unlock_bh(&ax25_dev_lock);
 144         dev->ax25_ptr = NULL;
 145
 146         ax25_register_sysctl();
 147 }
 148
 149 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 150 {
 151         ax25_dev *ax25_dev, *fwd_dev;
 152
 153         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 154                 return -EINVAL;
 155
 156         switch (cmd) {
 157         case SIOCAX25ADDFWD:
 158                 if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
 159                         return -EINVAL;
 160                 if (ax25_dev->forward != NULL)
 161                         return -EINVAL;
 162                 ax25_dev->forward = fwd_dev->dev;
 163                 break;
 164
 165         case SIOCAX25DELFWD:
 166                 if (ax25_dev->forward == NULL)
 167                         return -EINVAL;
 168                 ax25_dev->forward = NULL;
 169                 break;
 170
 171         default:
 172                 return -EINVAL;
 173         }
 174
 175         return 0;
 176 }
 177
 178 struct net_device *ax25_fwd_dev(struct net_device *dev)
 179 {
 180         ax25_dev *ax25_dev;
 181
 182         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 183                 return dev;
 184
 185         if (ax25_dev->forward == NULL)
 186                 return dev;
 187
 188         return ax25_dev->forward;
 189 }
 190
 191 /*
 192  *      Free all memory associated with device structures.
 193  */
 194 void __exit ax25_dev_free(void)
 195 {
 196         ax25_dev *s, *ax25_dev;
 197
 198         spin_lock_bh(&ax25_dev_lock);
 199         ax25_dev = ax25_dev_list;
 200         while (ax25_dev != NULL) {
 201                 s        = ax25_dev;
 202                 dev_put(ax25_dev->dev);
 203                 ax25_dev = ax25_dev->next;
 204                 kfree(s);
 205         }
 206         ax25_dev_list = NULL;
 207         spin_unlock_bh(&ax25_dev_lock);
 208 }