net/ax25/ax25_dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *
   4  * Copyright (C) Jonathan Naylor G4KLX ([email protected])
   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/list.h>
  26 #include <linux/mm.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/init.h>
  29
  30 static LIST_HEAD(ax25_dev_list);
  31 DEFINE_SPINLOCK(ax25_dev_lock);
  32
  33 ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
  34 {
  35         ax25_dev *ax25_dev, *res = NULL;
  36
  37         spin_lock_bh(&ax25_dev_lock);
  38         list_for_each_entry(ax25_dev, &ax25_dev_list, list)
  39                 if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) {
  40                         res = ax25_dev;
  41                         ax25_dev_hold(ax25_dev);
  42                         break;
  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         ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_KERNEL);
  58         if (!ax25_dev) {
  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         ax25_dev->dev     = dev;
  65         netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL);
  66         ax25_dev->forward = NULL;
  67         ax25_dev->device_up = true;
  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
  83 #ifdef CONFIG_AX25_DAMA_SLAVE
  84         ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;
  85 #endif
  86
  87 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
  88         ax25_ds_setup_timer(ax25_dev);
  89 #endif
  90
  91         spin_lock_bh(&ax25_dev_lock);
  92         list_add(&ax25_dev->list, &ax25_dev_list);
  93         dev->ax25_ptr     = ax25_dev;
  94         spin_unlock_bh(&ax25_dev_lock);
  95
  96         ax25_register_dev_sysctl(ax25_dev);
  97 }
  98
  99 void ax25_dev_device_down(struct net_device *dev)
 100 {
 101         ax25_dev *s, *ax25_dev;
 102
 103         if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
 104                 return;
 105
 106         ax25_unregister_dev_sysctl(ax25_dev);
 107
 108         spin_lock_bh(&ax25_dev_lock);
 109
 110 #ifdef CONFIG_AX25_DAMA_SLAVE
 111         timer_shutdown_sync(&ax25_dev->dama.slave_timer);
 112 #endif
 113
 114         /*
 115          *      Remove any packet forwarding that points to this device.
 116          */
 117         list_for_each_entry(s, &ax25_dev_list, list)
 118                 if (s->forward == dev)
 119                         s->forward = NULL;
 120
 121         list_for_each_entry(s, &ax25_dev_list, list) {
 122                 if (s == ax25_dev) {
 123                         list_del(&s->list);
 124                         break;
 125                 }
 126         }
 127
 128         dev->ax25_ptr = NULL;
 129         spin_unlock_bh(&ax25_dev_lock);
 130         netdev_put(dev, &ax25_dev->dev_tracker);
 131         ax25_dev_put(ax25_dev);
 132 }
 133
 134 int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
 135 {
 136         ax25_dev *ax25_dev, *fwd_dev;
 137
 138         if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
 139                 return -EINVAL;
 140
 141         switch (cmd) {
 142         case SIOCAX25ADDFWD:
 143                 fwd_dev = ax25_addr_ax25dev(&fwd->port_to);
 144                 if (!fwd_dev) {
 145                         ax25_dev_put(ax25_dev);
 146                         return -EINVAL;
 147                 }
 148                 if (ax25_dev->forward) {
 149                         ax25_dev_put(fwd_dev);
 150                         ax25_dev_put(ax25_dev);
 151                         return -EINVAL;
 152                 }
 153                 ax25_dev->forward = fwd_dev->dev;
 154                 ax25_dev_put(fwd_dev);
 155                 ax25_dev_put(ax25_dev);
 156                 break;
 157
 158         case SIOCAX25DELFWD:
 159                 if (!ax25_dev->forward) {
 160                         ax25_dev_put(ax25_dev);
 161                         return -EINVAL;
 162                 }
 163                 ax25_dev->forward = NULL;
 164                 ax25_dev_put(ax25_dev);
 165                 break;
 166
 167         default:
 168                 ax25_dev_put(ax25_dev);
 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, *n;
 194
 195         spin_lock_bh(&ax25_dev_lock);
 196         list_for_each_entry_safe(s, n, &ax25_dev_list, list) {
 197                 netdev_put(s->dev, &s->dev_tracker);
 198                 list_del(&s->list);
 199                 kfree(s);
 200         }
 201         spin_unlock_bh(&ax25_dev_lock);
 202 }