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 ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 79 return -EINVAL; 80 if (route->digi_count > AX25_MAX_DIGIS) 81 return -EINVAL; 82 83 write_lock_bh(&ax25_route_lock); 84 85 ax25_rt = ax25_route_list; 86 while (ax25_rt != NULL) { 87 if (ax25cmp(&ax25_rt->callsign, &route->dest_addr) == 0 && 88 ax25_rt->dev == ax25_dev->dev) { 89 kfree(ax25_rt->digipeat); 90 ax25_rt->digipeat = NULL; 91 if (route->digi_count != 0) { 92 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 93 write_unlock_bh(&ax25_route_lock); 94 return -ENOMEM; 95 } 96 ax25_rt->digipeat->lastrepeat = -1; 97 ax25_rt->digipeat->ndigi = route->digi_count; 98 for (i = 0; i < route->digi_count; i++) { 99 ax25_rt->digipeat->repeated[i] = 0; 100 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 101 } 102 } 103 write_unlock_bh(&ax25_route_lock); 104 return 0; 105 } 106 ax25_rt = ax25_rt->next; 107 } 108 109 if ((ax25_rt = kmalloc(sizeof(ax25_route), GFP_ATOMIC)) == NULL) { 110 write_unlock_bh(&ax25_route_lock); 111 return -ENOMEM; 112 } 113 114 refcount_set(&ax25_rt->refcount, 1); 115 ax25_rt->callsign = route->dest_addr; 116 ax25_rt->dev = ax25_dev->dev; 117 ax25_rt->digipeat = NULL; 118 ax25_rt->ip_mode = ' '; 119 if (route->digi_count != 0) { 120 if ((ax25_rt->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) { 121 write_unlock_bh(&ax25_route_lock); 122 kfree(ax25_rt); 123 return -ENOMEM; 124 } 125 ax25_rt->digipeat->lastrepeat = -1; 126 ax25_rt->digipeat->ndigi = route->digi_count; 127 for (i = 0; i < route->digi_count; i++) { 128 ax25_rt->digipeat->repeated[i] = 0; 129 ax25_rt->digipeat->calls[i] = route->digi_addr[i]; 130 } 131 } 132 ax25_rt->next = ax25_route_list; 133 ax25_route_list = ax25_rt; 134 write_unlock_bh(&ax25_route_lock); 135 136 return 0; 137 } 138 139 void __ax25_put_route(ax25_route *ax25_rt) 140 { 141 kfree(ax25_rt->digipeat); 142 kfree(ax25_rt); 143 } 144 145 static int ax25_rt_del(struct ax25_routes_struct *route) 146 { 147 ax25_route *s, *t, *ax25_rt; 148 ax25_dev *ax25_dev; 149 150 if ((ax25_dev = ax25_addr_ax25dev(&route->port_addr)) == NULL) 151 return -EINVAL; 152 153 write_lock_bh(&ax25_route_lock); 154 155 ax25_rt = ax25_route_list; 156 while (ax25_rt != NULL) { 157 s = ax25_rt; 158 ax25_rt = ax25_rt->next; 159 if (s->dev == ax25_dev->dev && 160 ax25cmp(&route->dest_addr, &s->callsign) == 0) { 161 if (ax25_route_list == s) { 162 ax25_route_list = s->next; 163 ax25_put_route(s); 164 } else { 165 for (t = ax25_route_list; t != NULL; t = t->next) { 166 if (t->next == s) { 167 t->next = s->next; 168 ax25_put_route(s); 169 break; 170 } 171 } 172 } 173 } 174 } 175 write_unlock_bh(&ax25_route_lock); 176 177 return 0; 178 } 179 180 static int ax25_rt_opt(struct ax25_route_opt_struct *rt_option) 181 { 182 ax25_route *ax25_rt; 183 ax25_dev *ax25_dev; 184 int err = 0; 185 186 if ((ax25_dev = ax25_addr_ax25dev(&rt_option->port_addr)) == NULL) 187 return -EINVAL; 188 189 write_lock_bh(&ax25_route_lock); 190 191 ax25_rt = ax25_route_list; 192 while (ax25_rt != NULL) { 193 if (ax25_rt->dev == ax25_dev->dev && 194 ax25cmp(&rt_option->dest_addr, &ax25_rt->callsign) == 0) { 195 switch (rt_option->cmd) { 196 case AX25_SET_RT_IPMODE: 197 switch (rt_option->arg) { 198 case ' ': 199 case 'D': 200 case 'V': 201 ax25_rt->ip_mode = rt_option->arg; 202 break; 203 default: 204 err = -EINVAL; 205 goto out; 206 } 207 break; 208 default: 209 err = -EINVAL; 210 goto out; 211 } 212 } 213 ax25_rt = ax25_rt->next; 214 } 215 216 out: 217 write_unlock_bh(&ax25_route_lock); 218 return err; 219 } 220 221 int ax25_rt_ioctl(unsigned int cmd, void __user *arg) 222 { 223 struct ax25_route_opt_struct rt_option; 224 struct ax25_routes_struct route; 225 226 switch (cmd) { 227 case SIOCADDRT: 228 if (copy_from_user(&route, arg, sizeof(route))) 229 return -EFAULT; 230 return ax25_rt_add(&route); 231 232 case SIOCDELRT: 233 if (copy_from_user(&route, arg, sizeof(route))) 234 return -EFAULT; 235 return ax25_rt_del(&route); 236 237 case SIOCAX25OPTRT: 238 if (copy_from_user(&rt_option, arg, sizeof(rt_option))) 239 return -EFAULT; 240 return ax25_rt_opt(&rt_option); 241 242 default: 243 return -EINVAL; 244 } 245 } 246 247 #ifdef CONFIG_PROC_FS 248 249 static void *ax25_rt_seq_start(struct seq_file *seq, loff_t *pos) 250 __acquires(ax25_route_lock) 251 { 252 struct ax25_route *ax25_rt; 253 int i = 1; 254 255 read_lock(&ax25_route_lock); 256 if (*pos == 0) 257 return SEQ_START_TOKEN; 258 259 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 260 if (i == *pos) 261 return ax25_rt; 262 ++i; 263 } 264 265 return NULL; 266 } 267 268 static void *ax25_rt_seq_next(struct seq_file *seq, void *v, loff_t *pos) 269 { 270 ++*pos; 271 return (v == SEQ_START_TOKEN) ? ax25_route_list : 272 ((struct ax25_route *) v)->next; 273 } 274 275 static void ax25_rt_seq_stop(struct seq_file *seq, void *v) 276 __releases(ax25_route_lock) 277 { 278 read_unlock(&ax25_route_lock); 279 } 280 281 static int ax25_rt_seq_show(struct seq_file *seq, void *v) 282 { 283 char buf[11]; 284 285 if (v == SEQ_START_TOKEN) 286 seq_puts(seq, "callsign dev mode digipeaters\n"); 287 else { 288 struct ax25_route *ax25_rt = v; 289 const char *callsign; 290 int i; 291 292 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0) 293 callsign = "default"; 294 else 295 callsign = ax2asc(buf, &ax25_rt->callsign); 296 297 seq_printf(seq, "%-9s %-4s", 298 callsign, 299 ax25_rt->dev ? ax25_rt->dev->name : "???"); 300 301 switch (ax25_rt->ip_mode) { 302 case 'V': 303 seq_puts(seq, " vc"); 304 break; 305 case 'D': 306 seq_puts(seq, " dg"); 307 break; 308 default: 309 seq_puts(seq, " *"); 310 break; 311 } 312 313 if (ax25_rt->digipeat != NULL) 314 for (i = 0; i < ax25_rt->digipeat->ndigi; i++) 315 seq_printf(seq, " %s", 316 ax2asc(buf, &ax25_rt->digipeat->calls[i])); 317 318 seq_puts(seq, "\n"); 319 } 320 return 0; 321 } 322 323 const struct seq_operations ax25_rt_seqops = { 324 .start = ax25_rt_seq_start, 325 .next = ax25_rt_seq_next, 326 .stop = ax25_rt_seq_stop, 327 .show = ax25_rt_seq_show, 328 }; 329 #endif 330 331 /* 332 * Find AX.25 route 333 * 334 * Only routes with a reference count of zero can be destroyed. 335 * Must be called with ax25_route_lock read locked. 336 */ 337 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev) 338 { 339 ax25_route *ax25_spe_rt = NULL; 340 ax25_route *ax25_def_rt = NULL; 341 ax25_route *ax25_rt; 342 343 /* 344 * Bind to the physical interface we heard them on, or the default 345 * route if none is found; 346 */ 347 for (ax25_rt = ax25_route_list; ax25_rt != NULL; ax25_rt = ax25_rt->next) { 348 if (dev == NULL) { 349 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev != NULL) 350 ax25_spe_rt = ax25_rt; 351 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev != NULL) 352 ax25_def_rt = ax25_rt; 353 } else { 354 if (ax25cmp(&ax25_rt->callsign, addr) == 0 && ax25_rt->dev == dev) 355 ax25_spe_rt = ax25_rt; 356 if (ax25cmp(&ax25_rt->callsign, &null_ax25_address) == 0 && ax25_rt->dev == dev) 357 ax25_def_rt = ax25_rt; 358 } 359 } 360 361 ax25_rt = ax25_def_rt; 362 if (ax25_spe_rt != NULL) 363 ax25_rt = ax25_spe_rt; 364 365 return ax25_rt; 366 } 367 368 /* 369 * Adjust path: If you specify a default route and want to connect 370 * a target on the digipeater path but w/o having a special route 371 * set before, the path has to be truncated from your target on. 372 */ 373 static inline void ax25_adjust_path(ax25_address *addr, ax25_digi *digipeat) 374 { 375 int k; 376 377 for (k = 0; k < digipeat->ndigi; k++) { 378 if (ax25cmp(addr, &digipeat->calls[k]) == 0) 379 break; 380 } 381 382 digipeat->ndigi = k; 383 } 384 385 386 /* 387 * Find which interface to use. 388 */ 389 int ax25_rt_autobind(ax25_cb *ax25, ax25_address *addr) 390 { 391 ax25_uid_assoc *user; 392 ax25_route *ax25_rt; 393 int err = 0; 394 395 ax25_route_lock_use(); 396 ax25_rt = ax25_get_route(addr, NULL); 397 if (!ax25_rt) { 398 ax25_route_lock_unuse(); 399 return -EHOSTUNREACH; 400 } 401 if ((ax25->ax25_dev = ax25_dev_ax25dev(ax25_rt->dev)) == NULL) { 402 err = -EHOSTUNREACH; 403 goto put; 404 } 405 406 user = ax25_findbyuid(current_euid()); 407 if (user) { 408 ax25->source_addr = user->call; 409 ax25_uid_put(user); 410 } else { 411 if (ax25_uid_policy && !capable(CAP_NET_BIND_SERVICE)) { 412 err = -EPERM; 413 goto put; 414 } 415 ax25->source_addr = *(ax25_address *)ax25->ax25_dev->dev->dev_addr; 416 } 417 418 if (ax25_rt->digipeat != NULL) { 419 ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi), 420 GFP_ATOMIC); 421 if (ax25->digipeat == NULL) { 422 err = -ENOMEM; 423 goto put; 424 } 425 ax25_adjust_path(addr, ax25->digipeat); 426 } 427 428 if (ax25->sk != NULL) { 429 local_bh_disable(); 430 bh_lock_sock(ax25->sk); 431 sock_reset_flag(ax25->sk, SOCK_ZAPPED); 432 bh_unlock_sock(ax25->sk); 433 local_bh_enable(); 434 } 435 436 put: 437 ax25_route_lock_unuse(); 438 return err; 439 } 440 441 struct sk_buff *ax25_rt_build_path(struct sk_buff *skb, ax25_address *src, 442 ax25_address *dest, ax25_digi *digi) 443 { 444 struct sk_buff *skbn; 445 unsigned char *bp; 446 int len; 447 448 len = digi->ndigi * AX25_ADDR_LEN; 449 450 if (skb_headroom(skb) < len) { 451 if ((skbn = skb_realloc_headroom(skb, len)) == NULL) { 452 printk(KERN_CRIT "AX.25: ax25_dg_build_path - out of memory\n"); 453 return NULL; 454 } 455 456 if (skb->sk != NULL) 457 skb_set_owner_w(skbn, skb->sk); 458 459 consume_skb(skb); 460 461 skb = skbn; 462 } 463 464 bp = skb_push(skb, len); 465 466 ax25_addr_build(bp, src, dest, digi, AX25_COMMAND, AX25_MODULUS); 467 468 return skb; 469 } 470 471 /* 472 * Free all memory associated with routing structures. 473 */ 474 void __exit ax25_rt_free(void) 475 { 476 ax25_route *s, *ax25_rt = ax25_route_list; 477 478 write_lock_bh(&ax25_route_lock); 479 while (ax25_rt != NULL) { 480 s = ax25_rt; 481 ax25_rt = ax25_rt->next; 482 483 kfree(s->digipeat); 484 kfree(s); 485 } 486 write_unlock_bh(&ax25_route_lock); 487 } 488