net/ax25/ax25_route.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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
   8  * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
   9  * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org)
  10  * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
  11  * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de)
  12  * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
  13  */
  14 #include <linux/errno.h>
  15 #include <linux/types.h>
  16 #include <linux/socket.h>
  17 #include <linux/timer.h>
  18 #include <linux/in.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/string.h>
  22 #include <linux/sockios.h>
  23 #include <linux/net.h>
  24 #include <net/ax25.h>
  25 #include <linux/inet.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/spinlock.h>
  30 #include <net/sock.h>
  31 #include <asm/uaccess.h>
  32 #include <asm/system.h>
  33 #include <linux/fcntl.h>
  34 #include <linux/mm.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/init.h>
  37 #include <linux/seq_file.h>
  38
  39 static ax25_route *ax25_route_list;
  40 static DEFINE_RWLOCK(ax25_route_lock);
  41
  42 static ax25_route *ax25_get_route(ax25_address *, struct net_device *);
  43
  44 void ax25_rt_device_down(struct net_device *dev)
  45 {
  46         ax25_route *s, *t, *ax25_rt;
  47
  48         write_lock(&ax25_route_lock);
  49         ax25_rt = ax25_route_list;
  50         while (ax25_rt != NULL) {
  51                 s       = ax25_rt;
  52                 ax25_rt = ax25_rt->next;
  53
  54                 if (s->dev == dev) {
  55                         if (ax25_route_list == s) {
  56                                 ax25_route_list = s->next;
  57                                 kfree(s->digipeat);
  58                                 kfree(s);
  59                         } else {
  60                                 for (t = ax25_route_list; t != NULL; t = t->next) {
  61                                         if (t->next == s) {
  62                                                 t->next = s->next;
  63                                                 kfree(s->digipeat);
  64                                                 kfree(s);
  65                                                 break;
  66                                         }
  67                                 }
  68                         }
  69                 }
  70         }
  71         write_unlock(&ax25_route_lock);
  72 }
  73
  74 static int ax25_rt_add(struct ax25_routes_struct *route)
  75 {
  76         ax25_route *ax25_rt;
  77         ax25_dev *ax25_dev;
  78         int i;
  79
  80         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
  81                 return -EINVAL;
  82         if (route->digi_count > AX25_MAX_DIGIS)
  83                 return -EINVAL;
  84
  85         write_lock(&ax25_route_lock);
  86
  87         ax25_rt = ax25_route_list;
  88         while (ax25_rt != NULL) {
  89                 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 &&
  90                             ax25_rt->dev == ax25_dev->dev) {
  91                         kfree(ax25_rt->digipeat);
  92                         ax25_rt->digipeat = NULL;
  93                         if (route->digi_count != 0) {
  94                                 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
  95                                         write_unlock(&ax25_route_lock);
  96                                         return -ENOMEM;
  97                                 }
  98                                 ax25_rt->digipeat->lastrepeat = -1;
  99                                 ax25_rt->digipeat->ndigi      = route->digi_count;
 100                                 for (i = 0; i < route->digi_count; i++) {
 101                                         ax25_rt->digipeat->repeated[i] = 0;
 102                                         ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
 103                                 }
 104                         }
 105                         write_unlock(&ax25_route_lock);
 106                         return 0;
 107                 }
 108                 ax25_rt = ax25_rt->next;
 109         }
 110
 111         if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) {
 112                 write_unlock(&ax25_route_lock);
 113                 return -ENOMEM;
 114         }
 115
 116         atomic_set(&ax25_rt->ref, 0);
 117         ax25_rt->callsign     = route->dest_addr;
 118         ax25_rt->dev          = ax25_dev->dev;
 119         ax25_rt->digipeat     = NULL;
 120         ax25_rt->ip_mode      = ' ';
 121         if (route->digi_count != 0) {
 122                 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
 123                         write_unlock(&ax25_route_lock);
 124                         kfree(ax25_rt);
 125                         return -ENOMEM;
 126                 }
 127                 ax25_rt->digipeat->lastrepeat = -1;
 128                 ax25_rt->digipeat->ndigi      = route->digi_count;
 129                 for (i = 0; i < route->digi_count; i++) {
 130                         ax25_rt->digipeat->repeated[i] = 0;
 131                         ax25_rt->digipeat->calls[i]    = route->digi_addr[i];
 132                 }
 133         }
 134         ax25_rt->next   = ax25_route_list;
 135         ax25_route_list = ax25_rt;
 136         write_unlock(&ax25_route_lock);
 137
 138         return 0;
 139 }
 140
 141 static void ax25_rt_destroy(ax25_route *ax25_rt)
 142 {
 143         if (atomic_read(&ax25_rt->ref) == 0) {
 144                 kfree(ax25_rt->digipeat);
 145                 kfree(ax25_rt);
 146                 return;
 147         }
 148
 149         /*
 150          * Uh...  Route is still in use; we can't yet destroy it.  Retry later.
 151          */
 152         init_timer(&ax25_rt->timer);
 153         ax25_rt->timer.data     = (unsigned long) ax25_rt;
 154         ax25_rt->timer.function = (void *) ax25_rt_destroy;
 155         ax25_rt->timer.expires  = jiffies + 5 * HZ;
 156
 157         add_timer(&ax25_rt->timer);
 158 }
 159
 160 static int ax25_rt_del(struct ax25_routes_struct *route)
 161 {
 162         ax25_route *s, *t, *ax25_rt;
 163         ax25_dev *ax25_dev;
 164
 165         if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL)
 166                 return -EINVAL;
 167
 168         write_lock(&ax25_route_lock);
 169
 170         ax25_rt = ax25_route_list;
 171         while (ax25_rt != NULL) {
 172                 s       = ax25_rt;
 173                 ax25_rt = ax25_rt->next;
 174                 if (s->dev == ax25_dev->dev &&
 175                     ax25cmp(&route->dest_addr, &s->callsign) == 0) {
 176                         if (ax25_route_list == s) {
 177                                 ax25_route_list = s->next;
 178                                 ax25_rt_destroy(s);
 179                         } else {
 180                                 for (t = ax25_route_list; t != NULL; t = t->next) {
 181                                         if (t->next == s) {
 182                                                 t->next = s->next;
 183                                                 ax25_rt_destroy(s);
 184                                                 break;
 185                                         }
 186                                 }
 187                         }
 188                 }
 189         }
 190         write_unlock(&ax25_route_lock);
 191
 192         return 0;
 193 }
 194
 195 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option)
 196 {
 197         ax25_route *ax25_rt;
 198         ax25_dev *ax25_dev;
 199         int err = 0;
 200
 201         if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL)
 202                 return -EINVAL;
 203
 204         write_lock(&ax25_route_lock);
 205
 206         ax25_rt = ax25_route_list;
 207         while (ax25_rt != NULL) {
 208                 if (ax25_rt->dev == ax25_dev->dev &&
 209                     ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) {
 210                         switch (rt_option->cmd) {
 211                         case AX25_SET_RT_IPMODE:
 212                                 switch (rt_option->arg) {
 213                                 case ' ':
 214                                 case 'D':
 215                                 case 'V':
 216                                         ax25_rt->ip_mode = rt_option->arg;
 217                                         break;
 218                                 default:
 219                                         err = -EINVAL;
 220                                         goto out;
 221                                 }
 222                                 break;
 223                         default:
 224                                 err = -EINVAL;
 225                                 goto out;
 226                         }
 227                 }
 228                 ax25_rt = ax25_rt->next;
 229         }
 230
 231 out:
 232         write_unlock(&ax25_route_lock);
 233         return err;
 234 }
 235
 236 int ax25_rt_ioctl(unsigned int cmd, void __user *arg)
 237 {
 238         struct ax25_route_opt_struct rt_option;
 239         struct ax25_routes_struct route;
 240
 241         switch (cmd) {
 242         case SIOCADDRT:
 243                 if (copy_from_user(&route, arg, sizeof(route)))
 244                         return -EFAULT;
 245                 return ax25_rt_add(&route);
 246
 247         case SIOCDELRT:
 248                 if (copy_from_user(&route, arg, sizeof(route)))
 249                         return -EFAULT;
 250                 return ax25_rt_del(&route);
 251
 252         case SIOCAX25OPTRT:
 253                 if (copy_from_user(&rt_option, arg, sizeof(rt_option)))
 254                         return -EFAULT;
 255                 return ax25_rt_opt(&rt_option);
 256
 257         default:
 258                 return -EINVAL;
 259         }
 260 }
 261
 262 #ifdef CONFIG_PROC_FS
 263
 264 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos)
 265 {
 266         struct ax25_route *ax25_rt;
 267         int i = 1;
 268
 269         read_lock(&ax25_route_lock);
 270         if (*pos == 0)
 271                 return SEQ_START_TOKEN;
 272
 273         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
 274                 if (i == *pos)
 275                         return ax25_rt;
 276                 ++i;
 277         }
 278
 279         return NULL;
 280 }
 281
 282 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 283 {
 284         ++*pos;
 285         return (v == SEQ_START_TOKEN) ? ax25_route_list :
 286                 ((struct ax25_route *) v)->next;
 287 }
 288
 289 static void ax25_rt_seq_stop(struct seq_file *seq, void *v)
 290 {
 291         read_unlock(&ax25_route_lock);
 292 }
 293
 294 static int ax25_rt_seq_show(struct seq_file *seq, void *v)
 295 {
 296         char buf[11];
 297
 298         if (v == SEQ_START_TOKEN)
 299                 seq_puts(seq, "callsign  dev  mode digipeaters\n");
 300         else {
 301                 struct ax25_route *ax25_rt = v;
 302                 const char *callsign;
 303                 int i;
 304
 305                 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0)
 306                         callsign = "default";
 307                 else
 308                         callsign = ax2asc(buf, &ax25_rt->callsign);
 309
 310                 seq_printf(seq, "%-9s %-4s",
 311                         callsign,
 312                         ax25_rt->dev ? ax25_rt->dev->name : "???");
 313
 314                 switch (ax25_rt->ip_mode) {
 315                 case 'V':
 316                         seq_puts(seq, "   vc");
 317                         break;
 318                 case 'D':
 319                         seq_puts(seq, "   dg");
 320                         break;
 321                 default:
 322                         seq_puts(seq, "    *");
 323                         break;
 324                 }
 325
 326                 if (ax25_rt->digipeat != NULL)
 327                         for (i = 0; i < ax25_rt->digipeat->ndigi; i++)
 328                                 seq_printf(seq, " %s",
 329                                      ax2asc(buf, &ax25_rt->digipeat->calls[i]));
 330
 331                 seq_puts(seq, "\n");
 332         }
 333         return 0;
 334 }
 335
 336 static struct seq_operations ax25_rt_seqops = {
 337         .start = ax25_rt_seq_start,
 338         .next = ax25_rt_seq_next,
 339         .stop = ax25_rt_seq_stop,
 340         .show = ax25_rt_seq_show,
 341 };
 342
 343 static int ax25_rt_info_open(struct inode *inode, struct file *file)
 344 {
 345         return seq_open(file, &ax25_rt_seqops);
 346 }
 347
 348 struct file_operations ax25_route_fops = {
 349         .owner = THIS_MODULE,
 350         .open = ax25_rt_info_open,
 351         .read = seq_read,
 352         .llseek = seq_lseek,
 353         .release = seq_release,
 354 };
 355
 356 #endif
 357
 358 /*
 359  *      Find AX.25 route
 360  *
 361  *      Only routes with a refernce rout of zero can be destroyed.
 362  */
 363 static ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev)
 364 {
 365         ax25_route *ax25_spe_rt = NULL;
 366         ax25_route *ax25_def_rt = NULL;
 367         ax25_route *ax25_rt;
 368
 369         read_lock(&ax25_route_lock);
 370         /*
 371          *      Bind to the physical interface we heard them on, or the default
 372          *      route if none is found;
 373          */
 374         for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) {
 375                 if (dev == NULL) {
 376                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL)
 377                                 ax25_spe_rt = ax25_rt;
 378                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL)
 379                                 ax25_def_rt = ax25_rt;
 380                 } else {
 381                         if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev)
 382                                 ax25_spe_rt = ax25_rt;
 383                         if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev)
 384                                 ax25_def_rt = ax25_rt;
 385                 }
 386         }
 387
 388         ax25_rt = ax25_def_rt;
 389         if (ax25_spe_rt != NULL)
 390                 ax25_rt = ax25_spe_rt;
 391
 392         if (ax25_rt != NULL)
 393                 atomic_inc(&ax25_rt->ref);
 394
 395         read_unlock(&ax25_route_lock);
 396
 397         return ax25_rt;
 398 }
 399
 400 /*
 401  *      Adjust path: If you specify a default route and want to connect
 402  *      a target on the digipeater path but w/o having a special route
 403  *      set before, the path has to be truncated from your target on.
 404  */
 405 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat)
 406 {
 407         int k;
 408
 409         for (k = 0; k < digipeat->ndigi; k++) {
 410                 if (ax25cmp(addr, &digipeat->calls[k]) == 0)
 411                         break;
 412         }
 413
 414         digipeat->ndigi = k;
 415 }
 416
 417
 418 /*
 419  *      Find which interface to use.
 420  */
 421 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr)
 422 {
 423         ax25_uid_assoc *user;
 424         ax25_route *ax25_rt;
 425         int err;
 426
 427         if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL)
 428                 return -EHOSTUNREACH;
 429
 430         if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) {
 431                 err = -EHOSTUNREACH;
 432                 goto put;
 433         }
 434
 435         user = ax25_findbyuid(current->euid);
 436         if (user) {
 437                 ax25->source_addr = user->call;
 438                 ax25_uid_put(user);
 439         } else {
 440                 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) {
 441                         err = -EPERM;
 442                         goto put;
 443                 }
 444                 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr;
 445         }
 446
 447         if (ax25_rt->digipeat != NULL) {
 448                 if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
 449                         err = -ENOMEM;
 450                         goto put;
 451                 }
 452                 memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi));
 453                 ax25_adjust_path(addr, ax25->digipeat);
 454         }
 455
 456         if (ax25->sk != NULL) {
 457                 bh_lock_sock(ax25->sk);
 458                 sock_reset_flag(ax25->sk, SOCK_ZAPPED);
 459                 bh_unlock_sock(ax25->sk);
 460         }
 461
 462 put:
 463         ax25_put_route(ax25_rt);
 464
 465         return 0;
 466 }
 467
 468 ax25_route *ax25_rt_find_route(ax25_route * route, ax25_address *addr,
 469         struct net_device *dev)
 470 {
 471         ax25_route *ax25_rt;
 472
 473         if ((ax25_rt = ax25_get_route(addr, dev)))
 474                 return ax25_rt;
 475
 476         route->next     = NULL;
 477         atomic_set(&route->ref, 1);
 478         route->callsign = *addr;
 479         route->dev      = dev;
 480         route->digipeat = NULL;
 481         route->ip_mode  = ' ';
 482
 483         return route;
 484 }
 485
 486 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src,
 487         ax25_address *dest, ax25_digi *digi)
 488 {
 489         struct sk_buff *skbn;
 490         unsigned char *bp;
 491         int len;
 492
 493         len = digi->ndigi * AX25_ADDR_LEN;
 494
 495         if (skb_headroom(skb) < len) {
 496                 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) {
 497                         printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n");
 498                         return NULL;
 499                 }
 500
 501                 if (skb->sk != NULL)
 502                         skb_set_owner_w(skbn, skb->sk);
 503
 504                 kfree_skb(skb);
 505
 506                 skb = skbn;
 507         }
 508
 509         bp = skb_push(skb, len);
 510
 511         ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS);
 512
 513         return skb;
 514 }
 515
 516 /*
 517  *      Free all memory associated with routing structures.
 518  */
 519 void __exit ax25_rt_free(void)
 520 {
 521         ax25_route *s, *ax25_rt = ax25_route_list;
 522
 523         write_lock(&ax25_route_lock);
 524         while (ax25_rt != NULL) {
 525                 s       = ax25_rt;
 526                 ax25_rt = ax25_rt->next;
 527
 528                 kfree(s->digipeat);
 529                 kfree(s);
 530         }
 531         write_unlock(&ax25_route_lock);
 532 }