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 void ax25_rt_device_down(struct net_device *dev) 45 { 46 ax25_route *s, *t, *ax25_rt; 47 48 write_lock_bh(&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_bh(&ax25_route_lock); 72 } 73 74 static int __must_check 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_bh(&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_bh(&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_bh(&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_bh(&ax25_route_lock); 113 return -ENOMEM; 114 } 115 116 atomic_set(&ax25_rt->refcount, 1); 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_bh(&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_bh(&ax25_route_lock); 137 138 return 0; 139 } 140 141 void __ax25_put_route(ax25_route *ax25_rt) 142 { 143 kfree(ax25_rt->digipeat); 144 kfree(ax25_rt); 145 } 146 147 static int ax25_rt_del(struct ax25_routes_struct *route) 148 { 149 ax25_route *s, *t, *ax25_rt; 150 ax25_dev *ax25_dev; 151 152 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 153 return -EINVAL; 154 155 write_lock_bh(&ax25_route_lock); 156 157 ax25_rt = ax25_route_list; 158 while (ax25_rt != NULL) { 159 s = ax25_rt; 160 ax25_rt = ax25_rt->next; 161 if (s->dev == ax25_dev->dev && 162 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 163 if (ax25_route_list == s) { 164 ax25_route_list = s->next; 165 ax25_put_route(s); 166 } else { 167 for (t = ax25_route_list; t != NULL; t = t->next) { 168 if (t->next == s) { 169 t->next = s->next; 170 ax25_put_route(s); 171 break; 172 } 173 } 174 } 175 } 176 } 177 write_unlock_bh(&ax25_route_lock); 178 179 return 0; 180 } 181 182 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 183 { 184 ax25_route *ax25_rt; 185 ax25_dev *ax25_dev; 186 int err = 0; 187 188 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 189 return -EINVAL; 190 191 write_lock_bh(&ax25_route_lock); 192 193 ax25_rt = ax25_route_list; 194 while (ax25_rt != NULL) { 195 if (ax25_rt->dev == ax25_dev->dev && 196 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 197 switch (rt_option->cmd) { 198 case AX25_SET_RT_IPMODE: 199 switch (rt_option->arg) { 200 case ' ': 201 case 'D': 202 case 'V': 203 ax25_rt->ip_mode = rt_option->arg; 204 break; 205 default: 206 err = -EINVAL; 207 goto out; 208 } 209 break; 210 default: 211 err = -EINVAL; 212 goto out; 213 } 214 } 215 ax25_rt = ax25_rt->next; 216 } 217 218 out: 219 write_unlock_bh(&ax25_route_lock); 220 return err; 221 } 222 223 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 224 { 225 struct ax25_route_opt_struct rt_option; 226 struct ax25_routes_struct route; 227 228 switch (cmd) { 229 case SIOCADDRT: 230 if (copy_from_user(&route, arg, sizeof(route))) 231 return -EFAULT; 232 return ax25_rt_add(&route); 233 234 case SIOCDELRT: 235 if (copy_from_user(&route, arg, sizeof(route))) 236 return -EFAULT; 237 return ax25_rt_del(&route); 238 239 case SIOCAX25OPTRT: 240 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 241 return -EFAULT; 242 return ax25_rt_opt(&rt_option); 243 244 default: 245 return -EINVAL; 246 } 247 } 248 249 #ifdef CONFIG_PROC_FS 250 251 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 252 __acquires(ax25_route_lock) 253 { 254 struct ax25_route *ax25_rt; 255 int i = 1; 256 257 read_lock(&ax25_route_lock); 258 if (*pos == 0) 259 return SEQ_START_TOKEN; 260 261 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 262 if (i == *pos) 263 return ax25_rt; 264 ++i; 265 } 266 267 return NULL; 268 } 269 270 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 271 { 272 ++*pos; 273 return (v == SEQ_START_TOKEN) ? ax25_route_list : 274 ((struct ax25_route *) v)->next; 275 } 276 277 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 278 __releases(ax25_route_lock) 279 { 280 read_unlock(&ax25_route_lock); 281 } 282 283 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 284 { 285 char buf[11]; 286 287 if (v == SEQ_START_TOKEN) 288 seq_puts(seq, "callsign dev mode digipeaters\n"); 289 else { 290 struct ax25_route *ax25_rt = v; 291 const char *callsign; 292 int i; 293 294 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 295 callsign = "default"; 296 else 297 callsign = ax2asc(buf, &ax25_rt->callsign); 298 299 seq_printf(seq, "%-9s %-4s", 300 callsign, 301 ax25_rt->dev ? ax25_rt->dev->name : "???"); 302 303 switch (ax25_rt->ip_mode) { 304 case 'V': 305 seq_puts(seq, " vc"); 306 break; 307 case 'D': 308 seq_puts(seq, " dg"); 309 break; 310 default: 311 seq_puts(seq, " *"); 312 break; 313 } 314 315 if (ax25_rt->digipeat != NULL) 316 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 317 seq_printf(seq, " %s", 318 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 319 320 seq_puts(seq, "\n"); 321 } 322 return 0; 323 } 324 325 static const struct seq_operations ax25_rt_seqops = { 326 .start = ax25_rt_seq_start, 327 .next = ax25_rt_seq_next, 328 .stop = ax25_rt_seq_stop, 329 .show = ax25_rt_seq_show, 330 }; 331 332 static int ax25_rt_info_open(struct inode *inode, struct file *file) 333 { 334 return seq_open(file, &ax25_rt_seqops); 335 } 336 337 const struct file_operations ax25_route_fops = { 338 .owner = THIS_MODULE, 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; 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 0; 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 kfree_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