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 15 #include <linux/capability.h> 16 #include <linux/errno.h> 17 #include <linux/types.h> 18 #include <linux/socket.h> 19 #include <linux/timer.h> 20 #include <linux/in.h> 21 #include <linux/kernel.h> 22 #include <linux/sched.h> 23 #include <linux/string.h> 24 #include <linux/sockios.h> 25 #include <linux/net.h> 26 #include <net/ax25.h> 27 #include <linux/inet.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/skbuff.h> 31 #include <linux/spinlock.h> 32 #include <net/sock.h> 33 #include <asm/uaccess.h> 34 #include <asm/system.h> 35 #include <linux/fcntl.h> 36 #include <linux/mm.h> 37 #include <linux/interrupt.h> 38 #include <linux/init.h> 39 #include <linux/seq_file.h> 40 41 static ax25_route *ax25_route_list; 42 static DEFINE_RWLOCK(ax25_route_lock); 43 44 static ax25_route *ax25_get_route(ax25_address *, struct net_device *); 45 46 void ax25_rt_device_down(struct net_device *dev) 47 { 48 ax25_route *s, *t, *ax25_rt; 49 50 write_lock(&ax25_route_lock); 51 ax25_rt = ax25_route_list; 52 while (ax25_rt != NULL) { 53 s = ax25_rt; 54 ax25_rt = ax25_rt->next; 55 56 if (s->dev == dev) { 57 if (ax25_route_list == s) { 58 ax25_route_list = s->next; 59 kfree(s->digipeat); 60 kfree(s); 61 } else { 62 for (t = ax25_route_list; t != NULL; t = t->next) { 63 if (t->next == s) { 64 t->next = s->next; 65 kfree(s->digipeat); 66 kfree(s); 67 break; 68 } 69 } 70 } 71 } 72 } 73 write_unlock(&ax25_route_lock); 74 } 75 76 static int ax25_rt_add(struct ax25_routes_struct *route) 77 { 78 ax25_route *ax25_rt; 79 ax25_dev *ax25_dev; 80 int i; 81 82 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 83 return -EINVAL; 84 if (route->digi_count > AX25_MAX_DIGIS) 85 return -EINVAL; 86 87 write_lock(&ax25_route_lock); 88 89 ax25_rt = ax25_route_list; 90 while (ax25_rt != NULL) { 91 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 && 92 ax25_rt->dev == ax25_dev->dev) { 93 kfree(ax25_rt->digipeat); 94 ax25_rt->digipeat = NULL; 95 if (route->digi_count != 0) { 96 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 97 write_unlock(&ax25_route_lock); 98 return -ENOMEM; 99 } 100 ax25_rt->digipeat->lastrepeat = -1; 101 ax25_rt->digipeat->ndigi = route->digi_count; 102 for (i = 0; i < route->digi_count; i++) { 103 ax25_rt->digipeat->repeated[i] = 0; 104 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 105 } 106 } 107 write_unlock(&ax25_route_lock); 108 return 0; 109 } 110 ax25_rt = ax25_rt->next; 111 } 112 113 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) { 114 write_unlock(&ax25_route_lock); 115 return -ENOMEM; 116 } 117 118 atomic_set(&ax25_rt->ref, 0); 119 ax25_rt->callsign = route->dest_addr; 120 ax25_rt->dev = ax25_dev->dev; 121 ax25_rt->digipeat = NULL; 122 ax25_rt->ip_mode = ' '; 123 if (route->digi_count != 0) { 124 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 125 write_unlock(&ax25_route_lock); 126 kfree(ax25_rt); 127 return -ENOMEM; 128 } 129 ax25_rt->digipeat->lastrepeat = -1; 130 ax25_rt->digipeat->ndigi = route->digi_count; 131 for (i = 0; i < route->digi_count; i++) { 132 ax25_rt->digipeat->repeated[i] = 0; 133 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 134 } 135 } 136 ax25_rt->next = ax25_route_list; 137 ax25_route_list = ax25_rt; 138 write_unlock(&ax25_route_lock); 139 140 return 0; 141 } 142 143 static void ax25_rt_destroy(ax25_route *ax25_rt) 144 { 145 if (atomic_read(&ax25_rt->ref) == 0) { 146 kfree(ax25_rt->digipeat); 147 kfree(ax25_rt); 148 return; 149 } 150 151 /* 152 * Uh... Route is still in use; we can't yet destroy it. Retry later. 153 */ 154 init_timer(&ax25_rt->timer); 155 ax25_rt->timer.data = (unsigned long) ax25_rt; 156 ax25_rt->timer.function = (void *) ax25_rt_destroy; 157 ax25_rt->timer.expires = jiffies + 5 * HZ; 158 159 add_timer(&ax25_rt->timer); 160 } 161 162 static int ax25_rt_del(struct ax25_routes_struct *route) 163 { 164 ax25_route *s, *t, *ax25_rt; 165 ax25_dev *ax25_dev; 166 167 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 168 return -EINVAL; 169 170 write_lock(&ax25_route_lock); 171 172 ax25_rt = ax25_route_list; 173 while (ax25_rt != NULL) { 174 s = ax25_rt; 175 ax25_rt = ax25_rt->next; 176 if (s->dev == ax25_dev->dev && 177 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 178 if (ax25_route_list == s) { 179 ax25_route_list = s->next; 180 ax25_rt_destroy(s); 181 } else { 182 for (t = ax25_route_list; t != NULL; t = t->next) { 183 if (t->next == s) { 184 t->next = s->next; 185 ax25_rt_destroy(s); 186 break; 187 } 188 } 189 } 190 } 191 } 192 write_unlock(&ax25_route_lock); 193 194 return 0; 195 } 196 197 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 198 { 199 ax25_route *ax25_rt; 200 ax25_dev *ax25_dev; 201 int err = 0; 202 203 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 204 return -EINVAL; 205 206 write_lock(&ax25_route_lock); 207 208 ax25_rt = ax25_route_list; 209 while (ax25_rt != NULL) { 210 if (ax25_rt->dev == ax25_dev->dev && 211 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 212 switch (rt_option->cmd) { 213 case AX25_SET_RT_IPMODE: 214 switch (rt_option->arg) { 215 case ' ': 216 case 'D': 217 case 'V': 218 ax25_rt->ip_mode = rt_option->arg; 219 break; 220 default: 221 err = -EINVAL; 222 goto out; 223 } 224 break; 225 default: 226 err = -EINVAL; 227 goto out; 228 } 229 } 230 ax25_rt = ax25_rt->next; 231 } 232 233 out: 234 write_unlock(&ax25_route_lock); 235 return err; 236 } 237 238 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 239 { 240 struct ax25_route_opt_struct rt_option; 241 struct ax25_routes_struct route; 242 243 switch (cmd) { 244 case SIOCADDRT: 245 if (copy_from_user(&route, arg, sizeof(route))) 246 return -EFAULT; 247 return ax25_rt_add(&route); 248 249 case SIOCDELRT: 250 if (copy_from_user(&route, arg, sizeof(route))) 251 return -EFAULT; 252 return ax25_rt_del(&route); 253 254 case SIOCAX25OPTRT: 255 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 256 return -EFAULT; 257 return ax25_rt_opt(&rt_option); 258 259 default: 260 return -EINVAL; 261 } 262 } 263 264 #ifdef CONFIG_PROC_FS 265 266 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 267 { 268 struct ax25_route *ax25_rt; 269 int i = 1; 270 271 read_lock(&ax25_route_lock); 272 if (*pos == 0) 273 return SEQ_START_TOKEN; 274 275 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 276 if (i == *pos) 277 return ax25_rt; 278 ++i; 279 } 280 281 return NULL; 282 } 283 284 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 285 { 286 ++*pos; 287 return (v == SEQ_START_TOKEN) ? ax25_route_list : 288 ((struct ax25_route *) v)->next; 289 } 290 291 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 292 { 293 read_unlock(&ax25_route_lock); 294 } 295 296 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 297 { 298 char buf[11]; 299 300 if (v == SEQ_START_TOKEN) 301 seq_puts(seq, "callsign dev mode digipeaters\n"); 302 else { 303 struct ax25_route *ax25_rt = v; 304 const char *callsign; 305 int i; 306 307 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 308 callsign = "default"; 309 else 310 callsign = ax2asc(buf, &ax25_rt->callsign); 311 312 seq_printf(seq, "%-9s %-4s", 313 callsign, 314 ax25_rt->dev ? ax25_rt->dev->name : "???"); 315 316 switch (ax25_rt->ip_mode) { 317 case 'V': 318 seq_puts(seq, " vc"); 319 break; 320 case 'D': 321 seq_puts(seq, " dg"); 322 break; 323 default: 324 seq_puts(seq, " *"); 325 break; 326 } 327 328 if (ax25_rt->digipeat != NULL) 329 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 330 seq_printf(seq, " %s", 331 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 332 333 seq_puts(seq, "\n"); 334 } 335 return 0; 336 } 337 338 static struct seq_operations ax25_rt_seqops = { 339 .start = ax25_rt_seq_start, 340 .next = ax25_rt_seq_next, 341 .stop = ax25_rt_seq_stop, 342 .show = ax25_rt_seq_show, 343 }; 344 345 static int ax25_rt_info_open(struct inode *inode, struct file *file) 346 { 347 return seq_open(file, &ax25_rt_seqops); 348 } 349 350 struct file_operations ax25_route_fops = { 351 .owner = THIS_MODULE, 352 .open = ax25_rt_info_open, 353 .read = seq_read, 354 .llseek = seq_lseek, 355 .release = seq_release, 356 }; 357 358 #endif 359 360 /* 361 * Find AX.25 route 362 * 363 * Only routes with a reference count of zero can be destroyed. 364 */ 365 static ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 366 { 367 ax25_route *ax25_spe_rt = NULL; 368 ax25_route *ax25_def_rt = NULL; 369 ax25_route *ax25_rt; 370 371 read_lock(&ax25_route_lock); 372 /* 373 * Bind to the physical interface we heard them on, or the default 374 * route if none is found; 375 */ 376 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 377 if (dev == NULL) { 378 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 379 ax25_spe_rt = ax25_rt; 380 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 381 ax25_def_rt = ax25_rt; 382 } else { 383 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 384 ax25_spe_rt = ax25_rt; 385 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 386 ax25_def_rt = ax25_rt; 387 } 388 } 389 390 ax25_rt = ax25_def_rt; 391 if (ax25_spe_rt != NULL) 392 ax25_rt = ax25_spe_rt; 393 394 if (ax25_rt != NULL) 395 atomic_inc(&ax25_rt->ref); 396 397 read_unlock(&ax25_route_lock); 398 399 return ax25_rt; 400 } 401 402 /* 403 * Adjust path: If you specify a default route and want to connect 404 * a target on the digipeater path but w/o having a special route 405 * set before, the path has to be truncated from your target on. 406 */ 407 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 408 { 409 int k; 410 411 for (k = 0; k < digipeat->ndigi; k++) { 412 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 413 break; 414 } 415 416 digipeat->ndigi = k; 417 } 418 419 420 /* 421 * Find which interface to use. 422 */ 423 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 424 { 425 ax25_uid_assoc *user; 426 ax25_route *ax25_rt; 427 int err; 428 429 if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL) 430 return -EHOSTUNREACH; 431 432 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 433 err = -EHOSTUNREACH; 434 goto put; 435 } 436 437 user = ax25_findbyuid(current->euid); 438 if (user) { 439 ax25->source_addr = user->call; 440 ax25_uid_put(user); 441 } else { 442 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 443 err = -EPERM; 444 goto put; 445 } 446 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 447 } 448 449 if (ax25_rt->digipeat != NULL) { 450 if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 451 err = -ENOMEM; 452 goto put; 453 } 454 memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi)); 455 ax25_adjust_path(addr, ax25->digipeat); 456 } 457 458 if (ax25->sk != NULL) { 459 bh_lock_sock(ax25->sk); 460 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 461 bh_unlock_sock(ax25->sk); 462 } 463 464 put: 465 ax25_put_route(ax25_rt); 466 467 return 0; 468 } 469 470 ax25_route *ax25_rt_find_route(ax25_route * route, ax25_address *addr, 471 struct net_device *dev) 472 { 473 ax25_route *ax25_rt; 474 475 if ((ax25_rt = ax25_get_route(addr, dev))) 476 return ax25_rt; 477 478 route->next = NULL; 479 atomic_set(&route->ref, 1); 480 route->callsign = *addr; 481 route->dev = dev; 482 route->digipeat = NULL; 483 route->ip_mode = ' '; 484 485 return route; 486 } 487 488 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 489 ax25_address *dest, ax25_digi *digi) 490 { 491 struct sk_buff *skbn; 492 unsigned char *bp; 493 int len; 494 495 len = digi->ndigi * AX25_ADDR_LEN; 496 497 if (skb_headroom(skb) < len) { 498 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) { 499 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 500 return NULL; 501 } 502 503 if (skb->sk != NULL) 504 skb_set_owner_w(skbn, skb->sk); 505 506 kfree_skb(skb); 507 508 skb = skbn; 509 } 510 511 bp = skb_push(skb, len); 512 513 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 514 515 return skb; 516 } 517 518 /* 519 * Free all memory associated with routing structures. 520 */ 521 void __exit ax25_rt_free(void) 522 { 523 ax25_route *s, *ax25_rt = ax25_route_list; 524 525 write_lock(&ax25_route_lock); 526 while (ax25_rt != NULL) { 527 s = ax25_rt; 528 ax25_rt = ax25_rt->next; 529 530 kfree(s->digipeat); 531 kfree(s); 532 } 533 write_unlock(&ax25_route_lock); 534 } 535