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 } 533