net/x25/x25_route.c

   1 /*
   2  *      X.25 Packet Layer release 002
   3  *
   4  *      This is ALPHA test software. This code may break your machine, randomly fail to work with new
   5  *      releases, misbehave and/or generally screw up. It might even work.
   6  *
   7  *      This code REQUIRES 2.1.15 or higher
   8  *
   9  *      This module:
  10  *              This module is free software; you can redistribute it and/or
  11  *              modify it under the terms of the GNU General Public License
  12  *              as published by the Free Software Foundation; either version
  13  *              2 of the License, or (at your option) any later version.
  14  *
  15  *      History
  16  *      X.25 001        Jonathan Naylor Started coding.
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/socket.h>
  23 #include <linux/in.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/timer.h>
  27 #include <linux/string.h>
  28 #include <linux/sockios.h>
  29 #include <linux/net.h>
  30 #include <linux/inet.h>
  31 #include <linux/netdevice.h>
  32 #include <net/arp.h>
  33 #include <linux/if_arp.h>
  34 #include <linux/skbuff.h>
  35 #include <net/sock.h>
  36 #include <asm/segment.h>
  37 #include <asm/system.h>
  38 #include <asm/uaccess.h>
  39 #include <linux/fcntl.h>
  40 #include <linux/termios.h>      /* For TIOCINQ/OUTQ */
  41 #include <linux/mm.h>
  42 #include <linux/interrupt.h>
  43 #include <linux/notifier.h>
  44 #include <linux/init.h>
  45 #include <net/x25.h>
  46
  47 static struct x25_route *x25_route_list /* = NULL initially */;
  48
  49 /*
  50  *      Add a new route.
  51  */
  52 static int x25_add_route(x25_address *address, unsigned int sigdigits, struct net_device *dev)
  53 {
  54         struct x25_route *x25_route;
  55         unsigned long flags;
  56
  57         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next)
  58                 if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits)
  59                         return -EINVAL;
  60
  61         if ((x25_route = kmalloc(sizeof(*x25_route), GFP_ATOMIC)) == NULL)
  62                 return -ENOMEM;
  63
  64         strcpy(x25_route->address.x25_addr, "000000000000000");
  65         memcpy(x25_route->address.x25_addr, address->x25_addr, sigdigits);
  66
  67         x25_route->sigdigits = sigdigits;
  68         x25_route->dev       = dev;
  69
  70         save_flags(flags); cli();
  71         x25_route->next = x25_route_list;
  72         x25_route_list  = x25_route;
  73         restore_flags(flags);
  74
  75         return 0;
  76 }
  77
  78 static void x25_remove_route(struct x25_route *x25_route)
  79 {
  80         struct x25_route *s;
  81         unsigned long flags;
  82
  83         save_flags(flags);
  84         cli();
  85
  86         if ((s = x25_route_list) == x25_route) {
  87                 x25_route_list = x25_route->next;
  88                 restore_flags(flags);
  89                 kfree(x25_route);
  90                 return;
  91         }
  92
  93         while (s != NULL && s->next != NULL) {
  94                 if (s->next == x25_route) {
  95                         s->next = x25_route->next;
  96                         restore_flags(flags);
  97                         kfree(x25_route);
  98                         return;
  99                 }
 100
 101                 s = s->next;
 102         }
 103
 104         restore_flags(flags);
 105 }
 106
 107 static int x25_del_route(x25_address *address, unsigned int sigdigits, struct net_device *dev)
 108 {
 109         struct x25_route *x25_route;
 110
 111         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {
 112                 if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits && x25_route->dev == dev) {
 113                         x25_remove_route(x25_route);
 114                         return 0;
 115                 }
 116         }
 117
 118         return -EINVAL;
 119 }
 120
 121 /*
 122  *      A device has been removed, remove its routes.
 123  */
 124 void x25_route_device_down(struct net_device *dev)
 125 {
 126         struct x25_route *route, *x25_route = x25_route_list;
 127
 128         while (x25_route != NULL) {
 129                 route     = x25_route;
 130                 x25_route = x25_route->next;
 131
 132                 if (route->dev == dev)
 133                         x25_remove_route(route);
 134         }
 135 }
 136
 137 /*
 138  *      Check that the device given is a valid X.25 interface that is "up".
 139  */
 140 struct net_device *x25_dev_get(char *devname)
 141 {
 142         struct net_device *dev;
 143
 144         if ((dev = dev_get_by_name(devname)) == NULL)
 145                 return NULL;
 146
 147         if ((dev->flags & IFF_UP) && (dev->type == ARPHRD_X25
 148 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
 149            || dev->type == ARPHRD_ETHER
 150 #endif
 151            ))
 152                 return dev;
 153
 154         dev_put(dev);
 155
 156         return NULL;
 157 }
 158
 159 /*
 160  *      Find a device given an X.25 address.
 161  */
 162 struct net_device *x25_get_route(x25_address *addr)
 163 {
 164         struct x25_route *route, *use = NULL;
 165
 166         for (route = x25_route_list; route != NULL; route = route->next) {
 167                 if (memcmp(&route->address, addr, route->sigdigits) == 0) {
 168                         if (use == NULL) {
 169                                 use = route;
 170                         } else {
 171                                 if (route->sigdigits > use->sigdigits)
 172                                         use = route;
 173                         }
 174                 }
 175         }
 176
 177         return (use != NULL) ? use->dev : NULL;
 178 }
 179
 180 /*
 181  *      Handle the ioctls that control the routing functions.
 182  */
 183 int x25_route_ioctl(unsigned int cmd, void *arg)
 184 {
 185         struct x25_route_struct x25_route;
 186         struct net_device *dev;
 187         int err;
 188
 189         switch (cmd) {
 190
 191                 case SIOCADDRT:
 192                         if (copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct)))
 193                                 return -EFAULT;
 194                         if (x25_route.sigdigits < 0 || x25_route.sigdigits > 15)
 195                                 return -EINVAL;
 196                         if ((dev = x25_dev_get(x25_route.device)) == NULL)
 197                                 return -EINVAL;
 198                         err = x25_add_route(&x25_route.address, x25_route.sigdigits, dev);
 199                         dev_put(dev);
 200                         return err;
 201
 202                 case SIOCDELRT:
 203                         if (copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct)))
 204                                 return -EFAULT;
 205                         if (x25_route.sigdigits < 0 || x25_route.sigdigits > 15)
 206                                 return -EINVAL;
 207                         if ((dev = x25_dev_get(x25_route.device)) == NULL)
 208                                 return -EINVAL;
 209                         err = x25_del_route(&x25_route.address, x25_route.sigdigits, dev);
 210                         dev_put(dev);
 211                         return err;
 212
 213                 default:
 214                         return -EINVAL;
 215         }
 216
 217         return 0;
 218 }
 219
 220 int x25_routes_get_info(char *buffer, char **start, off_t offset, int length)
 221 {
 222         struct x25_route *x25_route;
 223         int len     = 0;
 224         off_t pos   = 0;
 225         off_t begin = 0;
 226
 227         cli();
 228
 229         len += sprintf(buffer, "address          digits  device\n");
 230
 231         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {
 232                 len += sprintf(buffer + len, "%-15s  %-6d  %-5s\n",
 233                         x25_route->address.x25_addr,
 234                         x25_route->sigdigits,
 235                         (x25_route->dev != NULL) ? x25_route->dev->name : "???");
 236
 237                 pos = begin + len;
 238
 239                 if (pos < offset) {
 240                         len   = 0;
 241                         begin = pos;
 242                 }
 243
 244                 if (pos > offset + length)
 245                         break;
 246         }
 247
 248         sti();
 249
 250         *start = buffer + (offset - begin);
 251         len   -= (offset - begin);
 252
 253         if (len > length) len = length;
 254
 255         return len;
 256 }
 257
 258 /*
 259  *      Release all memory associated with X.25 routing structures.
 260  */
 261 void __exit x25_route_free(void)
 262 {
 263         struct x25_route *route, *x25_route = x25_route_list;
 264
 265         while (x25_route != NULL) {
 266                 route     = x25_route;
 267                 x25_route = x25_route->next;
 268
 269                 x25_remove_route(route);
 270         }
 271 }