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 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 ax25_dev_put(ax25_dev); 128 return -ENOMEM; 129 } 130 ax25_rt->digipeat->lastrepeat = -1; 131 ax25_rt->digipeat->ndigi = route->digi_count; 132 for (i = 0; i < route->digi_count; i++) { 133 ax25_rt->digipeat->repeated[i] = 0; 134 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 135 } 136 } 137 ax25_rt->next = ax25_route_list; 138 ax25_route_list = ax25_rt; 139 write_unlock_bh(&ax25_route_lock); 140 ax25_dev_put(ax25_dev); 141 142 return 0; 143 } 144 145 void __ax25_put_route(ax25_route *ax25_rt) 146 { 147 kfree(ax25_rt->digipeat); 148 kfree(ax25_rt); 149 } 150 151 static int ax25_rt_del(struct ax25_routes_struct *route) 152 { 153 ax25_route *s, *t, *ax25_rt; 154 ax25_dev *ax25_dev; 155 156 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 157 return -EINVAL; 158 159 write_lock_bh(&ax25_route_lock); 160 161 ax25_rt = ax25_route_list; 162 while (ax25_rt != NULL) { 163 s = ax25_rt; 164 ax25_rt = ax25_rt->next; 165 if (s->dev == ax25_dev->dev && 166 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 167 if (ax25_route_list == s) { 168 ax25_route_list = s->next; 169 __ax25_put_route(s); 170 } else { 171 for (t = ax25_route_list; t != NULL; t = t->next) { 172 if (t->next == s) { 173 t->next = s->next; 174 __ax25_put_route(s); 175 break; 176 } 177 } 178 } 179 } 180 } 181 write_unlock_bh(&ax25_route_lock); 182 ax25_dev_put(ax25_dev); 183 184 return 0; 185 } 186 187 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 188 { 189 ax25_route *ax25_rt; 190 ax25_dev *ax25_dev; 191 int err = 0; 192 193 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 194 return -EINVAL; 195 196 write_lock_bh(&ax25_route_lock); 197 198 ax25_rt = ax25_route_list; 199 while (ax25_rt != NULL) { 200 if (ax25_rt->dev == ax25_dev->dev && 201 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 202 switch (rt_option->cmd) { 203 case AX25_SET_RT_IPMODE: 204 switch (rt_option->arg) { 205 case ' ': 206 case 'D': 207 case 'V': 208 ax25_rt->ip_mode = rt_option->arg; 209 break; 210 default: 211 err = -EINVAL; 212 goto out; 213 } 214 break; 215 default: 216 err = -EINVAL; 217 goto out; 218 } 219 } 220 ax25_rt = ax25_rt->next; 221 } 222 223 out: 224 write_unlock_bh(&ax25_route_lock); 225 ax25_dev_put(ax25_dev); 226 return err; 227 } 228 229 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 230 { 231 struct ax25_route_opt_struct rt_option; 232 struct ax25_routes_struct route; 233 234 switch (cmd) { 235 case SIOCADDRT: 236 if (copy_from_user(&route, arg, sizeof(route))) 237 return -EFAULT; 238 return ax25_rt_add(&route); 239 240 case SIOCDELRT: 241 if (copy_from_user(&route, arg, sizeof(route))) 242 return -EFAULT; 243 return ax25_rt_del(&route); 244 245 case SIOCAX25OPTRT: 246 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 247 return -EFAULT; 248 return ax25_rt_opt(&rt_option); 249 250 default: 251 return -EINVAL; 252 } 253 } 254 255 #ifdef CONFIG_PROC_FS 256 257 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 258 __acquires(ax25_route_lock) 259 { 260 struct ax25_route *ax25_rt; 261 int i = 1; 262 263 read_lock(&ax25_route_lock); 264 if (*pos == 0) 265 return SEQ_START_TOKEN; 266 267 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 268 if (i == *pos) 269 return ax25_rt; 270 ++i; 271 } 272 273 return NULL; 274 } 275 276 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 277 { 278 ++*pos; 279 return (v == SEQ_START_TOKEN) ? ax25_route_list : 280 ((struct ax25_route *) v)->next; 281 } 282 283 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 284 __releases(ax25_route_lock) 285 { 286 read_unlock(&ax25_route_lock); 287 } 288 289 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 290 { 291 char buf[11]; 292 293 if (v == SEQ_START_TOKEN) 294 seq_puts(seq, "callsign dev mode digipeaters\n"); 295 else { 296 struct ax25_route *ax25_rt = v; 297 const char *callsign; 298 int i; 299 300 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 301 callsign = "default"; 302 else 303 callsign = ax2asc(buf, &ax25_rt->callsign); 304 305 seq_printf(seq, "%-9s %-4s", 306 callsign, 307 ax25_rt->dev ? ax25_rt->dev->name : "???"); 308 309 switch (ax25_rt->ip_mode) { 310 case 'V': 311 seq_puts(seq, " vc"); 312 break; 313 case 'D': 314 seq_puts(seq, " dg"); 315 break; 316 default: 317 seq_puts(seq, " *"); 318 break; 319 } 320 321 if (ax25_rt->digipeat != NULL) 322 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 323 seq_printf(seq, " %s", 324 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 325 326 seq_puts(seq, "\n"); 327 } 328 return 0; 329 } 330 331 const struct seq_operations ax25_rt_seqops = { 332 .start = ax25_rt_seq_start, 333 .next = ax25_rt_seq_next, 334 .stop = ax25_rt_seq_stop, 335 .show = ax25_rt_seq_show, 336 }; 337 #endif 338 339 /* 340 * Find AX.25 route 341 * 342 * Only routes with a reference count of zero can be destroyed. 343 * Must be called with ax25_route_lock read locked. 344 */ 345 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 346 { 347 ax25_route *ax25_spe_rt = NULL; 348 ax25_route *ax25_def_rt = NULL; 349 ax25_route *ax25_rt; 350 351 /* 352 * Bind to the physical interface we heard them on, or the default 353 * route if none is found; 354 */ 355 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 356 if (dev == NULL) { 357 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 358 ax25_spe_rt = ax25_rt; 359 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 360 ax25_def_rt = ax25_rt; 361 } else { 362 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 363 ax25_spe_rt = ax25_rt; 364 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 365 ax25_def_rt = ax25_rt; 366 } 367 } 368 369 ax25_rt = ax25_def_rt; 370 if (ax25_spe_rt != NULL) 371 ax25_rt = ax25_spe_rt; 372 373 return ax25_rt; 374 } 375 376 /* 377 * Adjust path: If you specify a default route and want to connect 378 * a target on the digipeater path but w/o having a special route 379 * set before, the path has to be truncated from your target on. 380 */ 381 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 382 { 383 int k; 384 385 for (k = 0; k < digipeat->ndigi; k++) { 386 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 387 break; 388 } 389 390 digipeat->ndigi = k; 391 } 392 393 394 /* 395 * Find which interface to use. 396 */ 397 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 398 { 399 ax25_uid_assoc *user; 400 ax25_route *ax25_rt; 401 int err = 0; 402 403 ax25_route_lock_use(); 404 ax25_rt = ax25_get_route(addr, NULL); 405 if (!ax25_rt) { 406 ax25_route_lock_unuse(); 407 return -EHOSTUNREACH; 408 } 409 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 410 err = -EHOSTUNREACH; 411 goto put; 412 } 413 414 user = ax25_findbyuid(current_euid()); 415 if (user) { 416 ax25->source_addr = user->call; 417 ax25_uid_put(user); 418 } else { 419 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 420 err = -EPERM; 421 goto put; 422 } 423 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 424 } 425 426 if (ax25_rt->digipeat != NULL) { 427 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi), 428 GFP_ATOMIC); 429 if (ax25->digipeat == NULL) { 430 err = -ENOMEM; 431 goto put; 432 } 433 ax25_adjust_path(addr, ax25->digipeat); 434 } 435 436 if (ax25->sk != NULL) { 437 local_bh_disable(); 438 bh_lock_sock(ax25->sk); 439 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 440 bh_unlock_sock(ax25->sk); 441 local_bh_enable(); 442 } 443 444 put: 445 ax25_route_lock_unuse(); 446 return err; 447 } 448 449 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 450 ax25_address *dest, ax25_digi *digi) 451 { 452 unsigned char *bp; 453 int len; 454 455 len = digi->ndigi * AX25_ADDR_LEN; 456 457 if (unlikely(skb_headroom(skb) < len)) { 458 skb = skb_expand_head(skb, len); 459 if (!skb) { 460 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 461 return NULL; 462 } 463 } 464 465 bp = skb_push(skb, len); 466 467 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 468 469 return skb; 470 } 471 472 /* 473 * Free all memory associated with routing structures. 474 */ 475 void __exit ax25_rt_free(void) 476 { 477 ax25_route *s, *ax25_rt = ax25_route_list; 478 479 write_lock_bh(&ax25_route_lock); 480 while (ax25_rt != NULL) { 481 s = ax25_rt; 482 ax25_rt = ax25_rt->next; 483 484 kfree(s->digipeat); 485 kfree(s); 486 } 487 write_unlock_bh(&ax25_route_lock); 488 } 489