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 if (s->digipeat != NULL) 58 kfree(s->digipeat); 59 kfree(s); 60 } else { 61 for (t = ax25_route_list; t != NULL; t = t->next) { 62 if (t->next == s) { 63 t->next = s->next; 64 if (s->digipeat != NULL) 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 if (ax25_rt->digipeat != NULL) { 94 kfree(ax25_rt->digipeat); 95 ax25_rt->digipeat = NULL; 96 } 97 if (route->digi_count != 0) { 98 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 99 write_unlock(&ax25_route_lock); 100 return -ENOMEM; 101 } 102 ax25_rt->digipeat->lastrepeat = -1; 103 ax25_rt->digipeat->ndigi = route->digi_count; 104 for (i = 0; i < route->digi_count; i++) { 105 ax25_rt->digipeat->repeated[i] = 0; 106 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 107 } 108 } 109 write_unlock(&ax25_route_lock); 110 return 0; 111 } 112 ax25_rt = ax25_rt->next; 113 } 114 115 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) { 116 write_unlock(&ax25_route_lock); 117 return -ENOMEM; 118 } 119 120 atomic_set(&ax25_rt->ref, 0); 121 ax25_rt->callsign = route->dest_addr; 122 ax25_rt->dev = ax25_dev->dev; 123 ax25_rt->digipeat = NULL; 124 ax25_rt->ip_mode = ' '; 125 if (route->digi_count != 0) { 126 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 127 write_unlock(&ax25_route_lock); 128 kfree(ax25_rt); 129 return -ENOMEM; 130 } 131 ax25_rt->digipeat->lastrepeat = -1; 132 ax25_rt->digipeat->ndigi = route->digi_count; 133 for (i = 0; i < route->digi_count; i++) { 134 ax25_rt->digipeat->repeated[i] = 0; 135 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 136 } 137 } 138 ax25_rt->next = ax25_route_list; 139 ax25_route_list = ax25_rt; 140 write_unlock(&ax25_route_lock); 141 142 return 0; 143 } 144 145 static void ax25_rt_destroy(ax25_route *ax25_rt) 146 { 147 if (atomic_read(&ax25_rt->ref) == 0) { 148 if (ax25_rt->digipeat != NULL) 149 kfree(ax25_rt->digipeat); 150 kfree(ax25_rt); 151 return; 152 } 153 154 /* 155 * Uh... Route is still in use; we can't yet destroy it. Retry later. 156 */ 157 init_timer(&ax25_rt->timer); 158 ax25_rt->timer.data = (unsigned long) ax25_rt; 159 ax25_rt->timer.function = (void *) ax25_rt_destroy; 160 ax25_rt->timer.expires = jiffies + 5 * HZ; 161 162 add_timer(&ax25_rt->timer); 163 } 164 165 static int ax25_rt_del(struct ax25_routes_struct *route) 166 { 167 ax25_route *s, *t, *ax25_rt; 168 ax25_dev *ax25_dev; 169 170 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 171 return -EINVAL; 172 173 write_lock(&ax25_route_lock); 174 175 ax25_rt = ax25_route_list; 176 while (ax25_rt != NULL) { 177 s = ax25_rt; 178 ax25_rt = ax25_rt->next; 179 if (s->dev == ax25_dev->dev && 180 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 181 if (ax25_route_list == s) { 182 ax25_route_list = s->next; 183 ax25_rt_destroy(s); 184 } else { 185 for (t = ax25_route_list; t != NULL; t = t->next) { 186 if (t->next == s) { 187 t->next = s->next; 188 ax25_rt_destroy(s); 189 break; 190 } 191 } 192 } 193 } 194 } 195 write_unlock(&ax25_route_lock); 196 197 return 0; 198 } 199 200 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 201 { 202 ax25_route *ax25_rt; 203 ax25_dev *ax25_dev; 204 int err = 0; 205 206 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 207 return -EINVAL; 208 209 write_lock(&ax25_route_lock); 210 211 ax25_rt = ax25_route_list; 212 while (ax25_rt != NULL) { 213 if (ax25_rt->dev == ax25_dev->dev && 214 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 215 switch (rt_option->cmd) { 216 case AX25_SET_RT_IPMODE: 217 switch (rt_option->arg) { 218 case ' ': 219 case 'D': 220 case 'V': 221 ax25_rt->ip_mode = rt_option->arg; 222 break; 223 default: 224 err = -EINVAL; 225 goto out; 226 } 227 break; 228 default: 229 err = -EINVAL; 230 goto out; 231 } 232 } 233 ax25_rt = ax25_rt->next; 234 } 235 236 out: 237 write_unlock(&ax25_route_lock); 238 return err; 239 } 240 241 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 242 { 243 struct ax25_route_opt_struct rt_option; 244 struct ax25_routes_struct route; 245 246 switch (cmd) { 247 case SIOCADDRT: 248 if (copy_from_user(&route, arg, sizeof(route))) 249 return -EFAULT; 250 return ax25_rt_add(&route); 251 252 case SIOCDELRT: 253 if (copy_from_user(&route, arg, sizeof(route))) 254 return -EFAULT; 255 return ax25_rt_del(&route); 256 257 case SIOCAX25OPTRT: 258 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 259 return -EFAULT; 260 return ax25_rt_opt(&rt_option); 261 262 default: 263 return -EINVAL; 264 } 265 } 266 267 #ifdef CONFIG_PROC_FS 268 269 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 270 { 271 struct ax25_route *ax25_rt; 272 int i = 1; 273 274 read_lock(&ax25_route_lock); 275 if (*pos == 0) 276 return SEQ_START_TOKEN; 277 278 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 279 if (i == *pos) 280 return ax25_rt; 281 ++i; 282 } 283 284 return NULL; 285 } 286 287 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 288 { 289 ++*pos; 290 return (v == SEQ_START_TOKEN) ? ax25_route_list : 291 ((struct ax25_route *) v)->next; 292 } 293 294 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 295 { 296 read_unlock(&ax25_route_lock); 297 } 298 299 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 300 { 301 char buf[11]; 302 303 if (v == SEQ_START_TOKEN) 304 seq_puts(seq, "callsign dev mode digipeaters\n"); 305 else { 306 struct ax25_route *ax25_rt = v; 307 const char *callsign; 308 int i; 309 310 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 311 callsign = "default"; 312 else 313 callsign = ax2asc(buf, &ax25_rt->callsign); 314 315 seq_printf(seq, "%-9s %-4s", 316 callsign, 317 ax25_rt->dev ? ax25_rt->dev->name : "???"); 318 319 switch (ax25_rt->ip_mode) { 320 case 'V': 321 seq_puts(seq, " vc"); 322 break; 323 case 'D': 324 seq_puts(seq, " dg"); 325 break; 326 default: 327 seq_puts(seq, " *"); 328 break; 329 } 330 331 if (ax25_rt->digipeat != NULL) 332 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 333 seq_printf(seq, " %s", 334 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 335 336 seq_puts(seq, "\n"); 337 } 338 return 0; 339 } 340 341 static struct seq_operations ax25_rt_seqops = { 342 .start = ax25_rt_seq_start, 343 .next = ax25_rt_seq_next, 344 .stop = ax25_rt_seq_stop, 345 .show = ax25_rt_seq_show, 346 }; 347 348 static int ax25_rt_info_open(struct inode *inode, struct file *file) 349 { 350 return seq_open(file, &ax25_rt_seqops); 351 } 352 353 struct file_operations ax25_route_fops = { 354 .owner = THIS_MODULE, 355 .open = ax25_rt_info_open, 356 .read = seq_read, 357 .llseek = seq_lseek, 358 .release = seq_release, 359 }; 360 361 #endif 362 363 /* 364 * Find AX.25 route 365 * 366 * Only routes with a refernce rout of zero can be destroyed. 367 */ 368 static ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 369 { 370 ax25_route *ax25_spe_rt = NULL; 371 ax25_route *ax25_def_rt = NULL; 372 ax25_route *ax25_rt; 373 374 read_lock(&ax25_route_lock); 375 /* 376 * Bind to the physical interface we heard them on, or the default 377 * route if none is found; 378 */ 379 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 380 if (dev == NULL) { 381 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 382 ax25_spe_rt = ax25_rt; 383 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 384 ax25_def_rt = ax25_rt; 385 } else { 386 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 387 ax25_spe_rt = ax25_rt; 388 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 389 ax25_def_rt = ax25_rt; 390 } 391 } 392 393 ax25_rt = ax25_def_rt; 394 if (ax25_spe_rt != NULL) 395 ax25_rt = ax25_spe_rt; 396 397 if (ax25_rt != NULL) 398 atomic_inc(&ax25_rt->ref); 399 400 read_unlock(&ax25_route_lock); 401 402 return ax25_rt; 403 } 404 405 /* 406 * Adjust path: If you specify a default route and want to connect 407 * a target on the digipeater path but w/o having a special route 408 * set before, the path has to be truncated from your target on. 409 */ 410 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 411 { 412 int k; 413 414 for (k = 0; k < digipeat->ndigi; k++) { 415 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 416 break; 417 } 418 419 digipeat->ndigi = k; 420 } 421 422 423 /* 424 * Find which interface to use. 425 */ 426 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 427 { 428 ax25_uid_assoc *user; 429 ax25_route *ax25_rt; 430 int err; 431 432 if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL) 433 return -EHOSTUNREACH; 434 435 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 436 err = -EHOSTUNREACH; 437 goto put; 438 } 439 440 user = ax25_findbyuid(current->euid); 441 if (user) { 442 ax25->source_addr = user->call; 443 ax25_uid_put(user); 444 } else { 445 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 446 err = -EPERM; 447 goto put; 448 } 449 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 450 } 451 452 if (ax25_rt->digipeat != NULL) { 453 if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 454 err = -ENOMEM; 455 goto put; 456 } 457 memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi)); 458 ax25_adjust_path(addr, ax25->digipeat); 459 } 460 461 if (ax25->sk != NULL) { 462 bh_lock_sock(ax25->sk); 463 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 464 bh_unlock_sock(ax25->sk); 465 } 466 467 put: 468 ax25_put_route(ax25_rt); 469 470 return 0; 471 } 472 473 ax25_route *ax25_rt_find_route(ax25_route * route, ax25_address *addr, 474 struct net_device *dev) 475 { 476 ax25_route *ax25_rt; 477 478 if ((ax25_rt = ax25_get_route(addr, dev))) 479 return ax25_rt; 480 481 route->next = NULL; 482 atomic_set(&route->ref, 1); 483 route->callsign = *addr; 484 route->dev = dev; 485 route->digipeat = NULL; 486 route->ip_mode = ' '; 487 488 return route; 489 } 490 491 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 492 ax25_address *dest, ax25_digi *digi) 493 { 494 struct sk_buff *skbn; 495 unsigned char *bp; 496 int len; 497 498 len = digi->ndigi * AX25_ADDR_LEN; 499 500 if (skb_headroom(skb) < len) { 501 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) { 502 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 503 return NULL; 504 } 505 506 if (skb->sk != NULL) 507 skb_set_owner_w(skbn, skb->sk); 508 509 kfree_skb(skb); 510 511 skb = skbn; 512 } 513 514 bp = skb_push(skb, len); 515 516 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 517 518 return skb; 519 } 520 521 /* 522 * Free all memory associated with routing structures. 523 */ 524 void __exit ax25_rt_free(void) 525 { 526 ax25_route *s, *ax25_rt = ax25_route_list; 527 528 write_lock(&ax25_route_lock); 529 while (ax25_rt != NULL) { 530 s = ax25_rt; 531 ax25_rt = ax25_rt->next; 532 533 if (s->digipeat != NULL) 534 kfree(s->digipeat); 535 536 kfree(s); 537 } 538 write_unlock(&ax25_route_lock); 539 } 540