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                         ax25_dev_hold(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         refcount_set(&ax25_dev->refcount, 1);
  64         dev->ax25_ptr     = ax25_dev;
  65         ax25_dev->dev     = dev;
  66         dev_hold(dev);
  67         ax25_dev->forward = NULL;
  68
  69         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  70         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  71         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  72         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  73         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  74         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  75         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  76         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  77         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  78         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  79         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  80         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  81         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  82         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  83
  84 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  85         ax25_ds_setup_timer(ax25_dev);
  86 #endif
  87
  88         spin_lock_bh(&ax25_dev_lock);
  89         ax25_dev->next = ax25_dev_list;
  90         ax25_dev_list  = ax25_dev;
  91         spin_unlock_bh(&ax25_dev_lock);
  92         ax25_dev_hold(ax25_dev);
  93
  94         ax25_register_dev_sysctl(ax25_dev);
  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_dev_sysctl(ax25_dev);
 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                 ax25_dev_put(ax25_dev);
 123                 dev->ax25_ptr = NULL;
 124                 dev_put(dev);
 125                 ax25_dev_put(ax25_dev);
 126                 return;
 127         }
 128
 129         while (s != NULL && s->next != NULL) {
 130                 if (s->next == ax25_dev) {
 131                         s->next = ax25_dev->next;
 132                         spin_unlock_bh(&ax25_dev_lock);
 133                         ax25_dev_put(ax25_dev);
 134                         dev->ax25_ptr = NULL;
 135                         dev_put(dev);
 136                         ax25_dev_put(ax25_dev);
 137                         return;
 138                 }
 139
 140                 s = s->next;
 141         }
 142         spin_unlock_bh(&ax25_dev_lock);
 143         dev->ax25_ptr = NULL;
 144         ax25_dev_put(ax25_dev);
 145 }
 146
 147 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 148 {
 149         ax25_dev *ax25_dev, *fwd_dev;
 150
 151         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 152                 return -EINVAL;
 153
 154         switch (cmd) {
 155         case SIOCAX25ADDFWD:
 156                 fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
 157                 if (!fwd_dev) {
 158                         ax25_dev_put(ax25_dev);
 159                         return -EINVAL;
 160                 }
 161                 if (ax25_dev->forward) {
 162                         ax25_dev_put(fwd_dev);
 163                         ax25_dev_put(ax25_dev);
 164                         return -EINVAL;
 165                 }
 166                 ax25_dev->forward = fwd_dev->dev;
 167                 ax25_dev_put(fwd_dev);
 168                 ax25_dev_put(ax25_dev);
 169                 break;
 170
 171         case SIOCAX25DELFWD:
 172                 if (!ax25_dev->forward) {
 173                         ax25_dev_put(ax25_dev);
 174                         return -EINVAL;
 175                 }
 176                 ax25_dev->forward = NULL;
 177                 ax25_dev_put(ax25_dev);
 178                 break;
 179
 180         default:
 181                 ax25_dev_put(ax25_dev);
 182                 return -EINVAL;
 183         }
 184
 185         return 0;
 186 }
 187
 188 struct net_device *ax25_fwd_dev(struct net_device *dev)
 189 {
 190         ax25_dev *ax25_dev;
 191
 192         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 193                 return dev;
 194
 195         if (ax25_dev->forward == NULL)
 196                 return dev;
 197
 198         return ax25_dev->forward;
 199 }
 200
 201 /*
 202  *      Free all memory associated with device structures.
 203  */
 204 void __exit ax25_dev_free(void)
 205 {
 206         ax25_dev *s, *ax25_dev;
 207
 208         spin_lock_bh(&ax25_dev_lock);
 209         ax25_dev = ax25_dev_list;
 210         while (ax25_dev != NULL) {
 211                 s        = ax25_dev;
 212                 dev_put(ax25_dev->dev);
 213                 ax25_dev = ax25_dev->next;
 214                 kfree(s);
 215         }
 216         ax25_dev_list = NULL;
 217         spin_unlock_bh(&ax25_dev_lock);
 218 }