1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright (C) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk) 5 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 6 * Copyright (C) Steven Whitehouse GW7RRM (stevew@acm.org) 7 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) 8 * Copyright (C) Hans-Joachim Hetscher DD8NE (dd8ne@bnv-bamberg.de) 9 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr) 10 */ 11 12 #include <linux/capability.h> 13 #include <linux/errno.h> 14 #include <linux/types.h> 15 #include <linux/socket.h> 16 #include <linux/timer.h> 17 #include <linux/in.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/string.h> 21 #include <linux/sockios.h> 22 #include <linux/net.h> 23 #include <linux/slab.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 <linux/uaccess.h> 32 #include <linux/fcntl.h> 33 #include <linux/mm.h> 34 #include <linux/interrupt.h> 35 #include <linux/init.h> 36 #include <linux/seq_file.h> 37 #include <linux/export.h> 38 39 static ax25_route *ax25_route_list; 40 DEFINE_RWLOCK(ax25_route_lock); 41 42 void ax25_rt_device_down(struct net_device *dev) 43 { 44 ax25_route *s, *t, *ax25_rt; 45 46 write_lock_bh(&ax25_route_lock); 47 ax25_rt = ax25_route_list; 48 while (ax25_rt != NULL) { 49 s = ax25_rt; 50 ax25_rt = ax25_rt->next; 51 52 if (s->dev == dev) { 53 if (ax25_route_list == s) { 54 ax25_route_list = s->next; 55 kfree(s->digipeat); 56 kfree(s); 57 } else { 58 for (t = ax25_route_list; t != NULL; t = t->next) { 59 if (t->next == s) { 60 t->next = s->next; 61 kfree(s->digipeat); 62 kfree(s); 63 break; 64 } 65 } 66 } 67 } 68 } 69 write_unlock_bh(&ax25_route_lock); 70 } 71 72 static int __must_check ax25_rt_add(struct ax25_routes_struct *route) 73 { 74 ax25_route *ax25_rt; 75 ax25_dev *ax25_dev; 76 int i; 77 78 if (route->digi_count > AX25_MAX_DIGIS) 79 return -EINVAL; 80 81 ax25_dev = ax25_addr_ax25dev(&route->port_addr); 82 if (!ax25_dev) 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 ax25_dev_put(ax25_dev); 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 ax25_dev_put(ax25_dev); 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 ax25_dev_put(ax25_dev); 116 return -ENOMEM; 117 } 118 119 refcount_set(&ax25_rt->refcount, 1); 120 ax25_rt->callsign = route->dest_addr; 121 ax25_rt->dev = ax25_dev->dev; 122 ax25_rt->digipeat = NULL; 123 ax25_rt->ip_mode = ' '; 124 if (route->digi_count != 0) { 125 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 126 write_unlock_bh(&ax25_route_lock); 127 kfree(ax25_rt); 128 ax25_dev_put(ax25_dev); 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_bh(&ax25_route_lock); 141 ax25_dev_put(ax25_dev); 142 143 return 0; 144 } 145 146 void __ax25_put_route(ax25_route *ax25_rt) 147 { 148 kfree(ax25_rt->digipeat); 149 kfree(ax25_rt); 150 } 151 152 static int ax25_rt_del(struct ax25_routes_struct *route) 153 { 154 ax25_route *s, *t, *ax25_rt; 155 ax25_dev *ax25_dev; 156 157 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 158 return -EINVAL; 159 160 write_lock_bh(&ax25_route_lock); 161 162 ax25_rt = ax25_route_list; 163 while (ax25_rt != NULL) { 164 s = ax25_rt; 165 ax25_rt = ax25_rt->next; 166 if (s->dev == ax25_dev->dev && 167 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 168 if (ax25_route_list == s) { 169 ax25_route_list = s->next; 170 ax25_put_route(s); 171 } else { 172 for (t = ax25_route_list; t != NULL; t = t->next) { 173 if (t->next == s) { 174 t->next = s->next; 175 ax25_put_route(s); 176 break; 177 } 178 } 179 } 180 } 181 } 182 write_unlock_bh(&ax25_route_lock); 183 ax25_dev_put(ax25_dev); 184 185 return 0; 186 } 187 188 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 189 { 190 ax25_route *ax25_rt; 191 ax25_dev *ax25_dev; 192 int err = 0; 193 194 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 195 return -EINVAL; 196 197 write_lock_bh(&ax25_route_lock); 198 199 ax25_rt = ax25_route_list; 200 while (ax25_rt != NULL) { 201 if (ax25_rt->dev == ax25_dev->dev && 202 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 203 switch (rt_option->cmd) { 204 case AX25_SET_RT_IPMODE: 205 switch (rt_option->arg) { 206 case ' ': 207 case 'D': 208 case 'V': 209 ax25_rt->ip_mode = rt_option->arg; 210 break; 211 default: 212 err = -EINVAL; 213 goto out; 214 } 215 break; 216 default: 217 err = -EINVAL; 218 goto out; 219 } 220 } 221 ax25_rt = ax25_rt->next; 222 } 223 224 out: 225 write_unlock_bh(&ax25_route_lock); 226 ax25_dev_put(ax25_dev); 227 return err; 228 } 229 230 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 231 { 232 struct ax25_route_opt_struct rt_option; 233 struct ax25_routes_struct route; 234 235 switch (cmd) { 236 case SIOCADDRT: 237 if (copy_from_user(&route, arg, sizeof(route))) 238 return -EFAULT; 239 return ax25_rt_add(&route); 240 241 case SIOCDELRT: 242 if (copy_from_user(&route, arg, sizeof(route))) 243 return -EFAULT; 244 return ax25_rt_del(&route); 245 246 case SIOCAX25OPTRT: 247 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 248 return -EFAULT; 249 return ax25_rt_opt(&rt_option); 250 251 default: 252 return -EINVAL; 253 } 254 } 255 256 #ifdef CONFIG_PROC_FS 257 258 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 259 __acquires(ax25_route_lock) 260 { 261 struct ax25_route *ax25_rt; 262 int i = 1; 263 264 read_lock(&ax25_route_lock); 265 if (*pos == 0) 266 return SEQ_START_TOKEN; 267 268 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 269 if (i == *pos) 270 return ax25_rt; 271 ++i; 272 } 273 274 return NULL; 275 } 276 277 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 278 { 279 ++*pos; 280 return (v == SEQ_START_TOKEN) ? ax25_route_list : 281 ((struct ax25_route *) v)->next; 282 } 283 284 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 285 __releases(ax25_route_lock) 286 { 287 read_unlock(&ax25_route_lock); 288 } 289 290 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 291 { 292 char buf[11]; 293 294 if (v == SEQ_START_TOKEN) 295 seq_puts(seq, "callsign dev mode digipeaters\n"); 296 else { 297 struct ax25_route *ax25_rt = v; 298 const char *callsign; 299 int i; 300 301 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 302 callsign = "default"; 303 else 304 callsign = ax2asc(buf, &ax25_rt->callsign); 305 306 seq_printf(seq, "%-9s %-4s", 307 callsign, 308 ax25_rt->dev ? ax25_rt->dev->name : "???"); 309 310 switch (ax25_rt->ip_mode) { 311 case 'V': 312 seq_puts(seq, " vc"); 313 break; 314 case 'D': 315 seq_puts(seq, " dg"); 316 break; 317 default: 318 seq_puts(seq, " *"); 319 break; 320 } 321 322 if (ax25_rt->digipeat != NULL) 323 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 324 seq_printf(seq, " %s", 325 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 326 327 seq_puts(seq, "\n"); 328 } 329 return 0; 330 } 331 332 const struct seq_operations ax25_rt_seqops = { 333 .start = ax25_rt_seq_start, 334 .next = ax25_rt_seq_next, 335 .stop = ax25_rt_seq_stop, 336 .show = ax25_rt_seq_show, 337 }; 338 #endif 339 340 /* 341 * Find AX.25 route 342 * 343 * Only routes with a reference count of zero can be destroyed. 344 * Must be called with ax25_route_lock read locked. 345 */ 346 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 347 { 348 ax25_route *ax25_spe_rt = NULL; 349 ax25_route *ax25_def_rt = NULL; 350 ax25_route *ax25_rt; 351 352 /* 353 * Bind to the physical interface we heard them on, or the default 354 * route if none is found; 355 */ 356 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 357 if (dev == NULL) { 358 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 359 ax25_spe_rt = ax25_rt; 360 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 361 ax25_def_rt = ax25_rt; 362 } else { 363 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 364 ax25_spe_rt = ax25_rt; 365 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 366 ax25_def_rt = ax25_rt; 367 } 368 } 369 370 ax25_rt = ax25_def_rt; 371 if (ax25_spe_rt != NULL) 372 ax25_rt = ax25_spe_rt; 373 374 return ax25_rt; 375 } 376 377 /* 378 * Adjust path: If you specify a default route and want to connect 379 * a target on the digipeater path but w/o having a special route 380 * set before, the path has to be truncated from your target on. 381 */ 382 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 383 { 384 int k; 385 386 for (k = 0; k < digipeat->ndigi; k++) { 387 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 388 break; 389 } 390 391 digipeat->ndigi = k; 392 } 393 394 395 /* 396 * Find which interface to use. 397 */ 398 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 399 { 400 ax25_uid_assoc *user; 401 ax25_route *ax25_rt; 402 int err = 0; 403 404 ax25_route_lock_use(); 405 ax25_rt = ax25_get_route(addr, NULL); 406 if (!ax25_rt) { 407 ax25_route_lock_unuse(); 408 return -EHOSTUNREACH; 409 } 410 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 411 err = -EHOSTUNREACH; 412 goto put; 413 } 414 415 user = ax25_findbyuid(current_euid()); 416 if (user) { 417 ax25->source_addr = user->call; 418 ax25_uid_put(user); 419 } else { 420 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 421 err = -EPERM; 422 goto put; 423 } 424 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 425 } 426 427 if (ax25_rt->digipeat != NULL) { 428 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi), 429 GFP_ATOMIC); 430 if (ax25->digipeat == NULL) { 431 err = -ENOMEM; 432 goto put; 433 } 434 ax25_adjust_path(addr, ax25->digipeat); 435 } 436 437 if (ax25->sk != NULL) { 438 local_bh_disable(); 439 bh_lock_sock(ax25->sk); 440 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 441 bh_unlock_sock(ax25->sk); 442 local_bh_enable(); 443 } 444 445 put: 446 ax25_route_lock_unuse(); 447 return err; 448 } 449 450 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 451 ax25_address *dest, ax25_digi *digi) 452 { 453 unsigned char *bp; 454 int len; 455 456 len = digi->ndigi * AX25_ADDR_LEN; 457 458 if (unlikely(skb_headroom(skb) < len)) { 459 skb = skb_expand_head(skb, len); 460 if (!skb) { 461 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 462 return NULL; 463 } 464 } 465 466 bp = skb_push(skb, len); 467 468 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 469 470 return skb; 471 } 472 473 /* 474 * Free all memory associated with routing structures. 475 */ 476 void __exit ax25_rt_free(void) 477 { 478 ax25_route *s, *ax25_rt = ax25_route_list; 479 480 write_lock_bh(&ax25_route_lock); 481 while (ax25_rt != NULL) { 482 s = ax25_rt; 483 ax25_rt = ax25_rt->next; 484 485 kfree(s->digipeat); 486 kfree(s); 487 } 488 write_unlock_bh(&ax25_route_lock); 489 } 490