net/x25/x25_route.c

   1 /*
   2  *      X.25 Packet Layer release 001
   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 #if defined(CONFIG_X25) || defined(CONFIG_X25_MODULE)
  21 #include <linux/errno.h>
  22 #include <linux/types.h>
  23 #include <linux/socket.h>
  24 #include <linux/in.h>
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/timer.h>
  28 #include <linux/string.h>
  29 #include <linux/sockios.h>
  30 #include <linux/net.h>
  31 #include <linux/inet.h>
  32 #include <linux/netdevice.h>
  33 #include <net/arp.h>
  34 #include <linux/if_arp.h>
  35 #include <linux/skbuff.h>
  36 #include <net/sock.h>
  37 #include <asm/segment.h>
  38 #include <asm/system.h>
  39 #include <asm/uaccess.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/termios.h>      /* For TIOCINQ/OUTQ */
  42 #include <linux/mm.h>
  43 #include <linux/interrupt.h>
  44 #include <linux/notifier.h>
  45 #include <linux/firewall.h>
  46 #include <net/x25.h>
  47
  48 static struct x25_route *x25_route_list = NULL;
  49
  50 /*
  51  *      Add a new route.
  52  */
  53 static int x25_add_route(x25_address *address, unsigned int sigdigits, struct device *dev)
  54 {
  55         struct x25_route *x25_route;
  56         unsigned long flags;
  57
  58         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next)
  59                 if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits)
  60                         return -EINVAL;
  61
  62         if ((x25_route = kmalloc(sizeof(*x25_route), GFP_ATOMIC)) == NULL)
  63                 return -ENOMEM;
  64
  65         strcpy(x25_route->address.x25_addr, "000000000000000");
  66         memcpy(x25_route->address.x25_addr, address->x25_addr, sigdigits);
  67
  68         x25_route->sigdigits = sigdigits;
  69         x25_route->dev       = dev;
  70
  71         save_flags(flags); cli();
  72         x25_route->next = x25_route_list;
  73         x25_route_list  = x25_route;
  74         restore_flags(flags);
  75
  76         return 0;
  77 }
  78
  79 static void x25_remove_route(struct x25_route *x25_route)
  80 {
  81         struct x25_route *s;
  82         unsigned long flags;
  83
  84         save_flags(flags);
  85         cli();
  86
  87         if ((s = x25_route_list) == x25_route) {
  88                 x25_route_list = x25_route->next;
  89                 restore_flags(flags);
  90                 kfree(x25_route);
  91                 return;
  92         }
  93
  94         while (s != NULL && s->next != NULL) {
  95                 if (s->next == x25_route) {
  96                         s->next = x25_route->next;
  97                         restore_flags(flags);
  98                         kfree(x25_route);
  99                         return;
 100                 }
 101
 102                 s = s->next;
 103         }
 104
 105         restore_flags(flags);
 106 }
 107
 108 static int x25_del_route(x25_address *address, unsigned int sigdigits, struct device *dev)
 109 {
 110         struct x25_route *x25_route;
 111
 112         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {
 113                 if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits && x25_route->dev == dev) {
 114                         x25_remove_route(x25_route);
 115                         return 0;
 116                 }
 117         }
 118
 119         return -EINVAL;
 120 }
 121
 122 /*
 123  *      A device has been removed, remove its routes.
 124  */
 125 void x25_route_device_down(struct device *dev)
 126 {
 127         struct x25_route *route, *x25_route = x25_route_list;
 128
 129         while (x25_route != NULL) {
 130                 route     = x25_route;
 131                 x25_route = x25_route->next;
 132
 133                 if (route->dev == dev)
 134                         x25_remove_route(route);
 135         }
 136 }
 137
 138 /*
 139  *      Check that the device given is a valid X.25 interface that is "up".
 140  */
 141 struct device *x25_dev_get(char *devname)
 142 {
 143         struct device *dev;
 144
 145         if ((dev = dev_get(devname)) == NULL)
 146                 return NULL;
 147
 148         if ((dev->flags & IFF_UP) && (dev->type == ARPHRD_X25
 149 #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)
 150            || dev->type == ARPHRD_ETHER
 151 #endif
 152            ))
 153                 return dev;
 154
 155         return NULL;
 156 }
 157
 158 /*
 159  *      Find a device given an X.25 address.
 160  */
 161 struct device *x25_get_route(x25_address *addr)
 162 {
 163         struct x25_route *route, *use = NULL;
 164
 165         for (route = x25_route_list; route != NULL; route = route->next) {
 166                 if (memcmp(&route->address, addr, route->sigdigits) == 0) {
 167                         if (use == NULL) {
 168                                 use = route;
 169                         } else {
 170                                 if (route->sigdigits > use->sigdigits)
 171                                         use = route;
 172                         }
 173                 }
 174         }
 175
 176         return (use != NULL) ? use->dev : NULL;
 177 }
 178
 179 /*
 180  *      Handle the ioctls that control the routing functions.
 181  */
 182 int x25_route_ioctl(unsigned int cmd, void *arg)
 183 {
 184         struct x25_route_struct x25_route;
 185         struct device *dev;
 186         int err;
 187
 188         switch (cmd) {
 189
 190                 case SIOCADDRT:
 191                         if ((err = verify_area(VERIFY_READ, arg, sizeof(struct x25_route_struct))) != 0)
 192                                 return err;
 193                         copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct));
 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                         return x25_add_route(&x25_route.address, x25_route.sigdigits, dev);
 199
 200                 case SIOCDELRT:
 201                         if ((err = verify_area(VERIFY_READ, arg, sizeof(struct x25_route_struct))) != 0)
 202                                 return err;
 203                         copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct));
 204                         if (x25_route.sigdigits < 0 || x25_route.sigdigits > 15)
 205                                 return -EINVAL;
 206                         if ((dev = x25_dev_get(x25_route.device)) == NULL)
 207                                 return -EINVAL;
 208                         return x25_del_route(&x25_route.address, x25_route.sigdigits, dev);
 209
 210                 default:
 211                         return -EINVAL;
 212         }
 213
 214         return 0;
 215 }
 216
 217 int x25_routes_get_info(char *buffer, char **start, off_t offset, int length, int dummy)
 218 {
 219         struct x25_route *x25_route;
 220         int len     = 0;
 221         off_t pos   = 0;
 222         off_t begin = 0;
 223
 224         cli();
 225
 226         len += sprintf(buffer, "address          digits  device\n");
 227
 228         for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {
 229                 len += sprintf(buffer + len, "%-15s  %-6d  %-5s\n",
 230                         x25_route->address.x25_addr, x25_route->sigdigits,
 231                         (x25_route->dev != NULL) ? x25_route->dev->name : "???");
 232
 233                 pos = begin + len;
 234
 235                 if (pos < offset) {
 236                         len   = 0;
 237                         begin = pos;
 238                 }
 239
 240                 if (pos > offset + length)
 241                         break;
 242         }
 243
 244         sti();
 245
 246         *start = buffer + (offset - begin);
 247         len   -= (offset - begin);
 248
 249         if (len > length) len = length;
 250
 251         return len;
 252 }
 253
 254 #ifdef MODULE
 255
 256 /*
 257  *      Release all memory associated with X.25 routing structures.
 258  */
 259 void x25_route_free(void)
 260 {
 261         struct x25_route *route, *x25_route = x25_route_list;
 262
 263         while (x25_route != NULL) {
 264                 route     = x25_route;
 265                 x25_route = x25_route->next;
 266
 267                 x25_remove_route(route);
 268         }
 269 }
 270
 271 #endif
 272
 273 #endif