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/slab.h>
  13 #include <linux/in.h>
  14 #include <linux/kernel.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 = kzalloc(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         dev->ax25_ptr     = ax25_dev;
  66         ax25_dev->dev     = dev;
  67         dev_hold(dev);
  68         ax25_dev->forward = NULL;
  69
  70         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  71         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  72         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  73         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  74         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  75         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  76         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  77         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  78         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  79         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  80         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  81         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  82         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  83         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  84
  85 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  86         ax25_ds_setup_timer(ax25_dev);
  87 #endif
  88
  89         spin_lock_bh(&ax25_dev_lock);
  90         ax25_dev->next = ax25_dev_list;
  91         ax25_dev_list  = ax25_dev;
  92         spin_unlock_bh(&ax25_dev_lock);
  93
  94         ax25_register_sysctl();
  95 }
  96
  97 void ax25_dev_device_down(struct net_device *dev)
  98 {
  99         ax25_dev *s, *ax25_dev;
 100
 101         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 102                 return;
 103
 104         ax25_unregister_sysctl();
 105
 106         spin_lock_bh(&ax25_dev_lock);
 107
 108 #ifdef CONFIG_AX25_DAMA_SLAVE
 109         ax25_ds_del_timer(ax25_dev);
 110 #endif
 111
 112         /*
 113          *      Remove any packet forwarding that points to this device.
 114          */
 115         for (s = ax25_dev_list; s != NULL; s = s->next)
 116                 if (s->forward == dev)
 117                         s->forward = NULL;
 118
 119         if ((s = ax25_dev_list) == ax25_dev) {
 120                 ax25_dev_list = s->next;
 121                 spin_unlock_bh(&ax25_dev_lock);
 122                 dev_put(dev);
 123                 kfree(ax25_dev);
 124                 ax25_register_sysctl();
 125                 return;
 126         }
 127
 128         while (s != NULL && s->next != NULL) {
 129                 if (s->next == ax25_dev) {
 130                         s->next = ax25_dev->next;
 131                         spin_unlock_bh(&ax25_dev_lock);
 132                         dev_put(dev);
 133                         kfree(ax25_dev);
 134                         ax25_register_sysctl();
 135                         return;
 136                 }
 137
 138                 s = s->next;
 139         }
 140         spin_unlock_bh(&ax25_dev_lock);
 141         dev->ax25_ptr = NULL;
 142
 143         ax25_register_sysctl();
 144 }
 145
 146 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 147 {
 148         ax25_dev *ax25_dev, *fwd_dev;
 149
 150         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 151                 return -EINVAL;
 152
 153         switch (cmd) {
 154         case SIOCAX25ADDFWD:
 155                 if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
 156                         return -EINVAL;
 157                 if (ax25_dev->forward != NULL)
 158                         return -EINVAL;
 159                 ax25_dev->forward = fwd_dev->dev;
 160                 break;
 161
 162         case SIOCAX25DELFWD:
 163                 if (ax25_dev->forward == NULL)
 164                         return -EINVAL;
 165                 ax25_dev->forward = NULL;
 166                 break;
 167
 168         default:
 169                 return -EINVAL;
 170         }
 171
 172         return 0;
 173 }
 174
 175 struct net_device *ax25_fwd_dev(struct net_device *dev)
 176 {
 177         ax25_dev *ax25_dev;
 178
 179         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 180                 return dev;
 181
 182         if (ax25_dev->forward == NULL)
 183                 return dev;
 184
 185         return ax25_dev->forward;
 186 }
 187
 188 /*
 189  *      Free all memory associated with device structures.
 190  */
 191 void __exit ax25_dev_free(void)
 192 {
 193         ax25_dev *s, *ax25_dev;
 194
 195         spin_lock_bh(&ax25_dev_lock);
 196         ax25_dev = ax25_dev_list;
 197         while (ax25_dev != NULL) {
 198                 s        = ax25_dev;
 199                 dev_put(ax25_dev->dev);
 200                 ax25_dev = ax25_dev->next;
 201                 kfree(s);
 202         }
 203         ax25_dev_list = NULL;
 204         spin_unlock_bh(&ax25_dev_lock);
 205 }