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 <linux/uaccess.h>
  27 #include <linux/fcntl.h>
  28 #include <linux/mm.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/init.h>
  31
  32 ax25_dev *ax25_dev_list;
  33 DEFINE_SPINLOCK(ax25_dev_lock);
  34
  35 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
  36 {
  37         ax25_dev *ax25_dev, *res = NULL;
  38
  39         spin_lock_bh(&ax25_dev_lock);
  40         for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
  41                 if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
  42                         res = ax25_dev;
  43                 }
  44         spin_unlock_bh(&ax25_dev_lock);
  45
  46         return res;
  47 }
  48
  49 /*
  50  *      This is called when an interface is brought up. These are
  51  *      reasonable defaults.
  52  */
  53 void ax25_dev_device_up(struct net_device *dev)
  54 {
  55         ax25_dev *ax25_dev;
  56
  57         if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
  58                 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
  59                 return;
  60         }
  61
  62         dev->ax25_ptr     = ax25_dev;
  63         ax25_dev->dev     = dev;
  64         dev_hold(dev);
  65         ax25_dev->forward = NULL;
  66
  67         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  68         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  69         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  70         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  71         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  72         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  73         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  74         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  75         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  76         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  77         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  78         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  79         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  80         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  81
  82 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  83         ax25_ds_setup_timer(ax25_dev);
  84 #endif
  85
  86         spin_lock_bh(&ax25_dev_lock);
  87         ax25_dev->next = ax25_dev_list;
  88         ax25_dev_list  = ax25_dev;
  89         spin_unlock_bh(&ax25_dev_lock);
  90
  91         ax25_register_dev_sysctl(ax25_dev);
  92 }
  93
  94 void ax25_dev_device_down(struct net_device *dev)
  95 {
  96         ax25_dev *s, *ax25_dev;
  97
  98         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
  99                 return;
 100
 101         ax25_unregister_dev_sysctl(ax25_dev);
 102
 103         spin_lock_bh(&ax25_dev_lock);
 104
 105 #ifdef CONFIG_AX25_DAMA_SLAVE
 106         ax25_ds_del_timer(ax25_dev);
 107 #endif
 108
 109         /*
 110          *      Remove any packet forwarding that points to this device.
 111          */
 112         for (s = ax25_dev_list; s != NULL; s = s->next)
 113                 if (s->forward == dev)
 114                         s->forward = NULL;
 115
 116         if ((s = ax25_dev_list) == ax25_dev) {
 117                 ax25_dev_list = s->next;
 118                 spin_unlock_bh(&ax25_dev_lock);
 119                 dev_put(dev);
 120                 kfree(ax25_dev);
 121                 return;
 122         }
 123
 124         while (s != NULL && s->next != NULL) {
 125                 if (s->next == ax25_dev) {
 126                         s->next = ax25_dev->next;
 127                         spin_unlock_bh(&ax25_dev_lock);
 128                         dev_put(dev);
 129                         kfree(ax25_dev);
 130                         return;
 131                 }
 132
 133                 s = s->next;
 134         }
 135         spin_unlock_bh(&ax25_dev_lock);
 136         dev->ax25_ptr = NULL;
 137 }
 138
 139 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 140 {
 141         ax25_dev *ax25_dev, *fwd_dev;
 142
 143         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 144                 return -EINVAL;
 145
 146         switch (cmd) {
 147         case SIOCAX25ADDFWD:
 148                 if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
 149                         return -EINVAL;
 150                 if (ax25_dev->forward != NULL)
 151                         return -EINVAL;
 152                 ax25_dev->forward = fwd_dev->dev;
 153                 break;
 154
 155         case SIOCAX25DELFWD:
 156                 if (ax25_dev->forward == NULL)
 157                         return -EINVAL;
 158                 ax25_dev->forward = NULL;
 159                 break;
 160
 161         default:
 162                 return -EINVAL;
 163         }
 164
 165         return 0;
 166 }
 167
 168 struct net_device *ax25_fwd_dev(struct net_device *dev)
 169 {
 170         ax25_dev *ax25_dev;
 171
 172         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 173                 return dev;
 174
 175         if (ax25_dev->forward == NULL)
 176                 return dev;
 177
 178         return ax25_dev->forward;
 179 }
 180
 181 /*
 182  *      Free all memory associated with device structures.
 183  */
 184 void __exit ax25_dev_free(void)
 185 {
 186         ax25_dev *s, *ax25_dev;
 187
 188         spin_lock_bh(&ax25_dev_lock);
 189         ax25_dev = ax25_dev_list;
 190         while (ax25_dev != NULL) {
 191                 s        = ax25_dev;
 192                 dev_put(ax25_dev->dev);
 193                 ax25_dev = ax25_dev->next;
 194                 kfree(s);
 195         }
 196         ax25_dev_list = NULL;
 197         spin_unlock_bh(&ax25_dev_lock);
 198 }