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 <asm/uaccess.h> 35 #include <asm/system.h> 36 #include <linux/fcntl.h> 37 #include <linux/mm.h> 38 #include <linux/interrupt.h> 39 #include <linux/init.h> 40 #include <linux/seq_file.h> 41 #include <linux/export.h> 42 43 static ax25_route *ax25_route_list; 44 static DEFINE_RWLOCK(ax25_route_lock); 45 46 void ax25_rt_device_down(struct net_device *dev) 47 { 48 ax25_route *s, *t, *ax25_rt; 49 50 write_lock_bh(&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_bh(&ax25_route_lock); 74 } 75 76 static int __must_check 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_bh(&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_bh(&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_bh(&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_bh(&ax25_route_lock); 115 return -ENOMEM; 116 } 117 118 atomic_set(&ax25_rt->refcount, 1); 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_bh(&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_bh(&ax25_route_lock); 139 140 return 0; 141 } 142 143 void __ax25_put_route(ax25_route *ax25_rt) 144 { 145 kfree(ax25_rt->digipeat); 146 kfree(ax25_rt); 147 } 148 149 static int ax25_rt_del(struct ax25_routes_struct *route) 150 { 151 ax25_route *s, *t, *ax25_rt; 152 ax25_dev *ax25_dev; 153 154 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 155 return -EINVAL; 156 157 write_lock_bh(&ax25_route_lock); 158 159 ax25_rt = ax25_route_list; 160 while (ax25_rt != NULL) { 161 s = ax25_rt; 162 ax25_rt = ax25_rt->next; 163 if (s->dev == ax25_dev->dev && 164 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 165 if (ax25_route_list == s) { 166 ax25_route_list = s->next; 167 ax25_put_route(s); 168 } else { 169 for (t = ax25_route_list; t != NULL; t = t->next) { 170 if (t->next == s) { 171 t->next = s->next; 172 ax25_put_route(s); 173 break; 174 } 175 } 176 } 177 } 178 } 179 write_unlock_bh(&ax25_route_lock); 180 181 return 0; 182 } 183 184 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 185 { 186 ax25_route *ax25_rt; 187 ax25_dev *ax25_dev; 188 int err = 0; 189 190 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 191 return -EINVAL; 192 193 write_lock_bh(&ax25_route_lock); 194 195 ax25_rt = ax25_route_list; 196 while (ax25_rt != NULL) { 197 if (ax25_rt->dev == ax25_dev->dev && 198 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 199 switch (rt_option->cmd) { 200 case AX25_SET_RT_IPMODE: 201 switch (rt_option->arg) { 202 case ' ': 203 case 'D': 204 case 'V': 205 ax25_rt->ip_mode = rt_option->arg; 206 break; 207 default: 208 err = -EINVAL; 209 goto out; 210 } 211 break; 212 default: 213 err = -EINVAL; 214 goto out; 215 } 216 } 217 ax25_rt = ax25_rt->next; 218 } 219 220 out: 221 write_unlock_bh(&ax25_route_lock); 222 return err; 223 } 224 225 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 226 { 227 struct ax25_route_opt_struct rt_option; 228 struct ax25_routes_struct route; 229 230 switch (cmd) { 231 case SIOCADDRT: 232 if (copy_from_user(&route, arg, sizeof(route))) 233 return -EFAULT; 234 return ax25_rt_add(&route); 235 236 case SIOCDELRT: 237 if (copy_from_user(&route, arg, sizeof(route))) 238 return -EFAULT; 239 return ax25_rt_del(&route); 240 241 case SIOCAX25OPTRT: 242 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 243 return -EFAULT; 244 return ax25_rt_opt(&rt_option); 245 246 default: 247 return -EINVAL; 248 } 249 } 250 251 #ifdef CONFIG_PROC_FS 252 253 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 254 __acquires(ax25_route_lock) 255 { 256 struct ax25_route *ax25_rt; 257 int i = 1; 258 259 read_lock(&ax25_route_lock); 260 if (*pos == 0) 261 return SEQ_START_TOKEN; 262 263 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 264 if (i == *pos) 265 return ax25_rt; 266 ++i; 267 } 268 269 return NULL; 270 } 271 272 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 273 { 274 ++*pos; 275 return (v == SEQ_START_TOKEN) ? ax25_route_list : 276 ((struct ax25_route *) v)->next; 277 } 278 279 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 280 __releases(ax25_route_lock) 281 { 282 read_unlock(&ax25_route_lock); 283 } 284 285 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 286 { 287 char buf[11]; 288 289 if (v == SEQ_START_TOKEN) 290 seq_puts(seq, "callsign dev mode digipeaters\n"); 291 else { 292 struct ax25_route *ax25_rt = v; 293 const char *callsign; 294 int i; 295 296 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 297 callsign = "default"; 298 else 299 callsign = ax2asc(buf, &ax25_rt->callsign); 300 301 seq_printf(seq, "%-9s %-4s", 302 callsign, 303 ax25_rt->dev ? ax25_rt->dev->name : "???"); 304 305 switch (ax25_rt->ip_mode) { 306 case 'V': 307 seq_puts(seq, " vc"); 308 break; 309 case 'D': 310 seq_puts(seq, " dg"); 311 break; 312 default: 313 seq_puts(seq, " *"); 314 break; 315 } 316 317 if (ax25_rt->digipeat != NULL) 318 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 319 seq_printf(seq, " %s", 320 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 321 322 seq_puts(seq, "\n"); 323 } 324 return 0; 325 } 326 327 static const struct seq_operations ax25_rt_seqops = { 328 .start = ax25_rt_seq_start, 329 .next = ax25_rt_seq_next, 330 .stop = ax25_rt_seq_stop, 331 .show = ax25_rt_seq_show, 332 }; 333 334 static int ax25_rt_info_open(struct inode *inode, struct file *file) 335 { 336 return seq_open(file, &ax25_rt_seqops); 337 } 338 339 const struct file_operations ax25_route_fops = { 340 .owner = THIS_MODULE, 341 .open = ax25_rt_info_open, 342 .read = seq_read, 343 .llseek = seq_lseek, 344 .release = seq_release, 345 }; 346 347 #endif 348 349 /* 350 * Find AX.25 route 351 * 352 * Only routes with a reference count of zero can be destroyed. 353 */ 354 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 355 { 356 ax25_route *ax25_spe_rt = NULL; 357 ax25_route *ax25_def_rt = NULL; 358 ax25_route *ax25_rt; 359 360 read_lock(&ax25_route_lock); 361 /* 362 * Bind to the physical interface we heard them on, or the default 363 * route if none is found; 364 */ 365 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 366 if (dev == NULL) { 367 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 368 ax25_spe_rt = ax25_rt; 369 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 370 ax25_def_rt = ax25_rt; 371 } else { 372 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 373 ax25_spe_rt = ax25_rt; 374 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 375 ax25_def_rt = ax25_rt; 376 } 377 } 378 379 ax25_rt = ax25_def_rt; 380 if (ax25_spe_rt != NULL) 381 ax25_rt = ax25_spe_rt; 382 383 if (ax25_rt != NULL) 384 ax25_hold_route(ax25_rt); 385 386 read_unlock(&ax25_route_lock); 387 388 return ax25_rt; 389 } 390 391 /* 392 * Adjust path: If you specify a default route and want to connect 393 * a target on the digipeater path but w/o having a special route 394 * set before, the path has to be truncated from your target on. 395 */ 396 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 397 { 398 int k; 399 400 for (k = 0; k < digipeat->ndigi; k++) { 401 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 402 break; 403 } 404 405 digipeat->ndigi = k; 406 } 407 408 409 /* 410 * Find which interface to use. 411 */ 412 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 413 { 414 ax25_uid_assoc *user; 415 ax25_route *ax25_rt; 416 int err = 0; 417 418 if ((ax25_rt = ax25_get_route(addr, NULL)) == NULL) 419 return -EHOSTUNREACH; 420 421 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 422 err = -EHOSTUNREACH; 423 goto put; 424 } 425 426 user = ax25_findbyuid(current_euid()); 427 if (user) { 428 ax25->source_addr = user->call; 429 ax25_uid_put(user); 430 } else { 431 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 432 err = -EPERM; 433 goto put; 434 } 435 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 436 } 437 438 if (ax25_rt->digipeat != NULL) { 439 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi), 440 GFP_ATOMIC); 441 if (ax25->digipeat == NULL) { 442 err = -ENOMEM; 443 goto put; 444 } 445 ax25_adjust_path(addr, ax25->digipeat); 446 } 447 448 if (ax25->sk != NULL) { 449 bh_lock_sock(ax25->sk); 450 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 451 bh_unlock_sock(ax25->sk); 452 } 453 454 put: 455 ax25_put_route(ax25_rt); 456 457 return err; 458 } 459 460 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 461 ax25_address *dest, ax25_digi *digi) 462 { 463 struct sk_buff *skbn; 464 unsigned char *bp; 465 int len; 466 467 len = digi->ndigi * AX25_ADDR_LEN; 468 469 if (skb_headroom(skb) < len) { 470 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) { 471 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 472 return NULL; 473 } 474 475 if (skb->sk != NULL) 476 skb_set_owner_w(skbn, skb->sk); 477 478 kfree_skb(skb); 479 480 skb = skbn; 481 } 482 483 bp = skb_push(skb, len); 484 485 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 486 487 return skb; 488 } 489 490 /* 491 * Free all memory associated with routing structures. 492 */ 493 void __exit ax25_rt_free(void) 494 { 495 ax25_route *s, *ax25_rt = ax25_route_list; 496 497 write_lock_bh(&ax25_route_lock); 498 while (ax25_rt != NULL) { 499 s = ax25_rt; 500 ax25_rt = ax25_rt->next; 501 502 kfree(s->digipeat); 503 kfree(s); 504 } 505 write_unlock_bh(&ax25_route_lock); 506 } 507