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 <linux/slab.h> 27 #include <net/ax25.h> 28 #include <linux/inet.h> 29 #include <linux/netdevice.h> 30 #include <linux/if_arp.h> 31 #include <linux/skbuff.h> 32 #include <linux/spinlock.h> 33 #include <net/sock.h> 34 #include <linux/uaccess.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 #include <linux/export.h> 41 42 static ax25_route *ax25_route_list; 43 static DEFINE_RWLOCK(ax25_route_lock); 44 45 void ax25_rt_device_down(struct net_device *dev) 46 { 47 ax25_route *s, *t, *ax25_rt; 48 49 write_lock_bh(&ax25_route_lock); 50 ax25_rt = ax25_route_list; 51 while (ax25_rt != NULL) { 52 s = ax25_rt; 53 ax25_rt = ax25_rt->next; 54 55 if (s->dev == dev) { 56 if (ax25_route_list == s) { 57 ax25_route_list = s->next; 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 kfree(s->digipeat); 65 kfree(s); 66 break; 67 } 68 } 69 } 70 } 71 } 72 write_unlock_bh(&ax25_route_lock); 73 } 74 75 static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 76 { 77 ax25_route *ax25_rt; 78 ax25_dev *ax25_dev; 79 int i; 80 81 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 82 return -EINVAL; 83 if (route->digi_count > AX25_MAX_DIGIS) 84 return -EINVAL; 85 86 write_lock_bh(&ax25_route_lock); 87 88 ax25_rt = ax25_route_list; 89 while (ax25_rt != NULL) { 90 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 && 91 ax25_rt->dev == ax25_dev->dev) { 92 kfree(ax25_rt->digipeat); 93 ax25_rt->digipeat = NULL; 94 if (route->digi_count != 0) { 95 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 96 write_unlock_bh(&ax25_route_lock); 97 return -ENOMEM; 98 } 99 ax25_rt->digipeat->lastrepeat = -1; 100 ax25_rt->digipeat->ndigi = route->digi_count; 101 for (i = 0; i < route->digi_count; i++) { 102 ax25_rt->digipeat->repeated[i] = 0; 103 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 104 } 105 } 106 write_unlock_bh(&ax25_route_lock); 107 return 0; 108 } 109 ax25_rt = ax25_rt->next; 110 } 111 112 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) { 113 write_unlock_bh(&ax25_route_lock); 114 return -ENOMEM; 115 } 116 117 refcount_set(&ax25_rt->refcount, 1); 118 ax25_rt->callsign = route->dest_addr; 119 ax25_rt->dev = ax25_dev->dev; 120 ax25_rt->digipeat = NULL; 121 ax25_rt->ip_mode = ' '; 122 if (route->digi_count != 0) { 123 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 124 write_unlock_bh(&ax25_route_lock); 125 kfree(ax25_rt); 126 return -ENOMEM; 127 } 128 ax25_rt->digipeat->lastrepeat = -1; 129 ax25_rt->digipeat->ndigi = route->digi_count; 130 for (i = 0; i < route->digi_count; i++) { 131 ax25_rt->digipeat->repeated[i] = 0; 132 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 133 } 134 } 135 ax25_rt->next = ax25_route_list; 136 ax25_route_list = ax25_rt; 137 write_unlock_bh(&ax25_route_lock); 138 139 return 0; 140 } 141 142 void __ax25_put_route(ax25_route *ax25_rt) 143 { 144 kfree(ax25_rt->digipeat); 145 kfree(ax25_rt); 146 } 147 148 static int ax25_rt_del(struct ax25_routes_struct *route) 149 { 150 ax25_route *s, *t, *ax25_rt; 151 ax25_dev *ax25_dev; 152 153 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 154 return -EINVAL; 155 156 write_lock_bh(&ax25_route_lock); 157 158 ax25_rt = ax25_route_list; 159 while (ax25_rt != NULL) { 160 s = ax25_rt; 161 ax25_rt = ax25_rt->next; 162 if (s->dev == ax25_dev->dev && 163 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 164 if (ax25_route_list == s) { 165 ax25_route_list = s->next; 166 ax25_put_route(s); 167 } else { 168 for (t = ax25_route_list; t != NULL; t = t->next) { 169 if (t->next == s) { 170 t->next = s->next; 171 ax25_put_route(s); 172 break; 173 } 174 } 175 } 176 } 177 } 178 write_unlock_bh(&ax25_route_lock); 179 180 return 0; 181 } 182 183 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 184 { 185 ax25_route *ax25_rt; 186 ax25_dev *ax25_dev; 187 int err = 0; 188 189 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 190 return -EINVAL; 191 192 write_lock_bh(&ax25_route_lock); 193 194 ax25_rt = ax25_route_list; 195 while (ax25_rt != NULL) { 196 if (ax25_rt->dev == ax25_dev->dev && 197 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 198 switch (rt_option->cmd) { 199 case AX25_SET_RT_IPMODE: 200 switch (rt_option->arg) { 201 case ' ': 202 case 'D': 203 case 'V': 204 ax25_rt->ip_mode = rt_option->arg; 205 break; 206 default: 207 err = -EINVAL; 208 goto out; 209 } 210 break; 211 default: 212 err = -EINVAL; 213 goto out; 214 } 215 } 216 ax25_rt = ax25_rt->next; 217 } 218 219 out: 220 write_unlock_bh(&ax25_route_lock); 221 return err; 222 } 223 224 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 225 { 226 struct ax25_route_opt_struct rt_option; 227 struct ax25_routes_struct route; 228 229 switch (cmd) { 230 case SIOCADDRT: 231 if (copy_from_user(&route, arg, sizeof(route))) 232 return -EFAULT; 233 return ax25_rt_add(&route); 234 235 case SIOCDELRT: 236 if (copy_from_user(&route, arg, sizeof(route))) 237 return -EFAULT; 238 return ax25_rt_del(&route); 239 240 case SIOCAX25OPTRT: 241 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 242 return -EFAULT; 243 return ax25_rt_opt(&rt_option); 244 245 default: 246 return -EINVAL; 247 } 248 } 249 250 #ifdef CONFIG_PROC_FS 251 252 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 253 __acquires(ax25_route_lock) 254 { 255 struct ax25_route *ax25_rt; 256 int i = 1; 257 258 read_lock(&ax25_route_lock); 259 if (*pos == 0) 260 return SEQ_START_TOKEN; 261 262 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 263 if (i == *pos) 264 return ax25_rt; 265 ++i; 266 } 267 268 return NULL; 269 } 270 271 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 272 { 273 ++*pos; 274 return (v == SEQ_START_TOKEN) ? ax25_route_list : 275 ((struct ax25_route *) v)->next; 276 } 277 278 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 279 __releases(ax25_route_lock) 280 { 281 read_unlock(&ax25_route_lock); 282 } 283 284 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 285 { 286 char buf[11]; 287 288 if (v == SEQ_START_TOKEN) 289 seq_puts(seq, "callsign dev mode digipeaters\n"); 290 else { 291 struct ax25_route *ax25_rt = v; 292 const char *callsign; 293 int i; 294 295 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 296 callsign = "default"; 297 else 298 callsign = ax2asc(buf, &ax25_rt->callsign); 299 300 seq_printf(seq, "%-9s %-4s", 301 callsign, 302 ax25_rt->dev ? ax25_rt->dev->name : "???"); 303 304 switch (ax25_rt->ip_mode) { 305 case 'V': 306 seq_puts(seq, " vc"); 307 break; 308 case 'D': 309 seq_puts(seq, " dg"); 310 break; 311 default: 312 seq_puts(seq, " *"); 313 break; 314 } 315 316 if (ax25_rt->digipeat != NULL) 317 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 318 seq_printf(seq, " %s", 319 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 320 321 seq_puts(seq, "\n"); 322 } 323 return 0; 324 } 325 326 static const struct seq_operations ax25_rt_seqops = { 327 .start = ax25_rt_seq_start, 328 .next = ax25_rt_seq_next, 329 .stop = ax25_rt_seq_stop, 330 .show = ax25_rt_seq_show, 331 }; 332 333 static int ax25_rt_info_open(struct inode *inode, struct file *file) 334 { 335 return seq_open(file, &ax25_rt_seqops); 336 } 337 338 const struct file_operations ax25_route_fops = { 339 .open = ax25_rt_info_open, 340 .read = seq_read, 341 .llseek = seq_lseek, 342 .release = seq_release, 343 }; 344 345 #endif 346 347 /* 348 * Find AX.25 route 349 * 350 * Only routes with a reference count of zero can be destroyed. 351 */ 352 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 353 { 354 ax25_route *ax25_spe_rt = NULL; 355 ax25_route *ax25_def_rt = NULL; 356 ax25_route *ax25_rt; 357 358 read_lock(&ax25_route_lock); 359 /* 360 * Bind to the physical interface we heard them on, or the default 361 * route if none is found; 362 */ 363 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 364 if (dev == NULL) { 365 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 366 ax25_spe_rt = ax25_rt; 367 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 368 ax25_def_rt = ax25_rt; 369 } else { 370 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 371 ax25_spe_rt = ax25_rt; 372 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 373 ax25_def_rt = ax25_rt; 374 } 375 } 376 377 ax25_rt = ax25_def_rt; 378 if (ax25_spe_rt != NULL) 379 ax25_rt = ax25_spe_rt; 380 381 if (ax25_rt != NULL) 382 ax25_hold_route(ax25_rt); 383 384 read_unlock(&ax25_route_lock); 385 386 return ax25_rt; 387 } 388 389 /* 390 * Adjust path: If you specify a default route and want to connect 391 * a target on the digipeater path but w/o having a special route 392 * set before, the path has to be truncated from your target on. 393 */ 394 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 395 { 396 int k; 397 398 for (k = 0; k < digipeat->ndigi; k++) { 399 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 400 break; 401 } 402 403 digipeat->ndigi = k; 404 } 405 406 407 /* 408 * Find which interface to use. 409 */ 410 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 411 { 412 ax25_uid_assoc *user; 413 ax25_route *ax25_rt; 414 int err = 0; 415 416 if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL) 417 return -EHOSTUNREACH; 418 419 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 420 err = -EHOSTUNREACH; 421 goto put; 422 } 423 424 user = ax25_findbyuid(current_euid()); 425 if (user) { 426 ax25->source_addr = user->call; 427 ax25_uid_put(user); 428 } else { 429 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 430 err = -EPERM; 431 goto put; 432 } 433 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 434 } 435 436 if (ax25_rt->digipeat != NULL) { 437 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi), 438 GFP_ATOMIC); 439 if (ax25->digipeat == NULL) { 440 err = -ENOMEM; 441 goto put; 442 } 443 ax25_adjust_path(addr, ax25->digipeat); 444 } 445 446 if (ax25->sk != NULL) { 447 bh_lock_sock(ax25->sk); 448 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 449 bh_unlock_sock(ax25->sk); 450 } 451 452 put: 453 ax25_put_route(ax25_rt); 454 455 return err; 456 } 457 458 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 459 ax25_address *dest, ax25_digi *digi) 460 { 461 struct sk_buff *skbn; 462 unsigned char *bp; 463 int len; 464 465 len = digi->ndigi * AX25_ADDR_LEN; 466 467 if (skb_headroom(skb) < len) { 468 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) { 469 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 470 return NULL; 471 } 472 473 if (skb->sk != NULL) 474 skb_set_owner_w(skbn, skb->sk); 475 476 consume_skb(skb); 477 478 skb = skbn; 479 } 480 481 bp = skb_push(skb, len); 482 483 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 484 485 return skb; 486 } 487 488 /* 489 * Free all memory associated with routing structures. 490 */ 491 void __exit ax25_rt_free(void) 492 { 493 ax25_route *s, *ax25_rt = ax25_route_list; 494 495 write_lock_bh(&ax25_route_lock); 496 while (ax25_rt != NULL) { 497 s = ax25_rt; 498 ax25_rt = ax25_rt->next; 499 500 kfree(s->digipeat); 501 kfree(s); 502 } 503 write_unlock_bh(&ax25_route_lock); 504 } 505