net/ax25/ax25_dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   5  */
   6 #include <linux/errno.h>
   7 #include <linux/types.h>
   8 #include <linux/socket.h>
   9 #include <linux/slab.h>
  10 #include <linux/in.h>
  11 #include <linux/kernel.h>
  12 #include <linux/timer.h>
  13 #include <linux/string.h>
  14 #include <linux/sockios.h>
  15 #include <linux/net.h>
  16 #include <linux/spinlock.h>
  17 #include <net/ax25.h>
  18 #include <linux/inet.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/if_arp.h>
  21 #include <linux/skbuff.h>
  22 #include <net/sock.h>
  23 #include <linux/uaccess.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/mm.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/init.h>
  28
  29 ax25_dev *ax25_dev_list;
  30 DEFINE_SPINLOCK(ax25_dev_lock);
  31
  32 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
  33 {
  34         ax25_dev *ax25_dev, *res = NULL;
  35
  36         spin_lock_bh(&ax25_dev_lock);
  37         for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
  38                 if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
  39                         res = ax25_dev;
  40                 }
  41         spin_unlock_bh(&ax25_dev_lock);
  42
  43         return res;
  44 }
  45
  46 /*
  47  *      This is called when an interface is brought up. These are
  48  *      reasonable defaults.
  49  */
  50 void ax25_dev_device_up(struct net_device *dev)
  51 {
  52         ax25_dev *ax25_dev;
  53
  54         if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
  55                 printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
  56                 return;
  57         }
  58
  59         dev->ax25_ptr     = ax25_dev;
  60         ax25_dev->dev     = dev;
  61         dev_hold(dev);
  62         ax25_dev->forward = NULL;
  63
  64         ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
  65         ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
  66         ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
  67         ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
  68         ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
  69         ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
  70         ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
  71         ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
  72         ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
  73         ax25_dev->values[AX25_VALUES_IDLE]      = AX25_DEF_IDLE;
  74         ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
  75         ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
  76         ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
  77         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  78
  79 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  80         ax25_ds_setup_timer(ax25_dev);
  81 #endif
  82
  83         spin_lock_bh(&ax25_dev_lock);
  84         ax25_dev->next = ax25_dev_list;
  85         ax25_dev_list  = ax25_dev;
  86         spin_unlock_bh(&ax25_dev_lock);
  87
  88         ax25_register_dev_sysctl(ax25_dev);
  89 }
  90
  91 void ax25_dev_device_down(struct net_device *dev)
  92 {
  93         ax25_dev *s, *ax25_dev;
  94
  95         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
  96                 return;
  97
  98         ax25_unregister_dev_sysctl(ax25_dev);
  99
 100         spin_lock_bh(&ax25_dev_lock);
 101
 102 #ifdef CONFIG_AX25_DAMA_SLAVE
 103         ax25_ds_del_timer(ax25_dev);
 104 #endif
 105
 106         /*
 107          *      Remove any packet forwarding that points to this device.
 108          */
 109         for (s = ax25_dev_list; s != NULL; s = s->next)
 110                 if (s->forward == dev)
 111                         s->forward = NULL;
 112
 113         if ((s = ax25_dev_list) == ax25_dev) {
 114                 ax25_dev_list = s->next;
 115                 spin_unlock_bh(&ax25_dev_lock);
 116                 dev->ax25_ptr = NULL;
 117                 dev_put(dev);
 118                 kfree(ax25_dev);
 119                 return;
 120         }
 121
 122         while (s != NULL && s->next != NULL) {
 123                 if (s->next == ax25_dev) {
 124                         s->next = ax25_dev->next;
 125                         spin_unlock_bh(&ax25_dev_lock);
 126                         dev->ax25_ptr = NULL;
 127                         dev_put(dev);
 128                         kfree(ax25_dev);
 129                         return;
 130                 }
 131
 132                 s = s->next;
 133         }
 134         spin_unlock_bh(&ax25_dev_lock);
 135         dev->ax25_ptr = NULL;
 136 }
 137
 138 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 139 {
 140         ax25_dev *ax25_dev, *fwd_dev;
 141
 142         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 143                 return -EINVAL;
 144
 145         switch (cmd) {
 146         case SIOCAX25ADDFWD:
 147                 if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
 148                         return -EINVAL;
 149                 if (ax25_dev->forward != NULL)
 150                         return -EINVAL;
 151                 ax25_dev->forward = fwd_dev->dev;
 152                 break;
 153
 154         case SIOCAX25DELFWD:
 155                 if (ax25_dev->forward == NULL)
 156                         return -EINVAL;
 157                 ax25_dev->forward = NULL;
 158                 break;
 159
 160         default:
 161                 return -EINVAL;
 162         }
 163
 164         return 0;
 165 }
 166
 167 struct net_device *ax25_fwd_dev(struct net_device *dev)
 168 {
 169         ax25_dev *ax25_dev;
 170
 171         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 172                 return dev;
 173
 174         if (ax25_dev->forward == NULL)
 175                 return dev;
 176
 177         return ax25_dev->forward;
 178 }
 179
 180 /*
 181  *      Free all memory associated with device structures.
 182  */
 183 void __exit ax25_dev_free(void)
 184 {
 185         ax25_dev *s, *ax25_dev;
 186
 187         spin_lock_bh(&ax25_dev_lock);
 188         ax25_dev = ax25_dev_list;
 189         while (ax25_dev != NULL) {
 190                 s        = ax25_dev;
 191                 dev_put(ax25_dev->dev);
 192                 ax25_dev = ax25_dev->next;
 193                 kfree(s);
 194         }
 195         ax25_dev_list = NULL;
 196         spin_unlock_bh(&ax25_dev_lock);
 197 }