1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 5 */ 6 #include <linux/errno.h> 7 #include <linux/types.h> 8 #include <linux/socket.h> 9 #include <linux/in.h> 10 #include <linux/kernel.h> 11 #include <linux/timer.h> 12 #include <linux/string.h> 13 #include <linux/sockios.h> 14 #include <linux/net.h> 15 #include <linux/slab.h> 16 #include <net/ax25.h> 17 #include <linux/inet.h> 18 #include <linux/netdevice.h> 19 #include <linux/skbuff.h> 20 #include <net/sock.h> 21 #include <net/tcp_states.h> 22 #include <linux/fcntl.h> 23 #include <linux/mm.h> 24 #include <linux/interrupt.h> 25 #include <net/rose.h> 26 27 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose); 28 29 /* 30 * This routine purges all of the queues of frames. 31 */ 32 void rose_clear_queues(struct sock *sk) 33 { 34 skb_queue_purge(&sk->sk_write_queue); 35 skb_queue_purge(&rose_sk(sk)->ack_queue); 36 } 37 38 /* 39 * This routine purges the input queue of those frames that have been 40 * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the 41 * SDL diagram. 42 */ 43 void rose_frames_acked(struct sock *sk, unsigned short nr) 44 { 45 struct sk_buff *skb; 46 struct rose_sock *rose = rose_sk(sk); 47 48 /* 49 * Remove all the ack-ed frames from the ack queue. 50 */ 51 if (rose->va != nr) { 52 while (skb_peek(&rose->ack_queue) != NULL && rose->va != nr) { 53 skb = skb_dequeue(&rose->ack_queue); 54 kfree_skb(skb); 55 rose->va = (rose->va + 1) % ROSE_MODULUS; 56 } 57 } 58 } 59 60 void rose_requeue_frames(struct sock *sk) 61 { 62 struct sk_buff *skb, *skb_prev = NULL; 63 64 /* 65 * Requeue all the un-ack-ed frames on the output queue to be picked 66 * up by rose_kick. This arrangement handles the possibility of an 67 * empty output queue. 68 */ 69 while ((skb = skb_dequeue(&rose_sk(sk)->ack_queue)) != NULL) { 70 if (skb_prev == NULL) 71 skb_queue_head(&sk->sk_write_queue, skb); 72 else 73 skb_append(skb_prev, skb, &sk->sk_write_queue); 74 skb_prev = skb; 75 } 76 } 77 78 /* 79 * Validate that the value of nr is between va and vs. Return true or 80 * false for testing. 81 */ 82 int rose_validate_nr(struct sock *sk, unsigned short nr) 83 { 84 struct rose_sock *rose = rose_sk(sk); 85 unsigned short vc = rose->va; 86 87 while (vc != rose->vs) { 88 if (nr == vc) return 1; 89 vc = (vc + 1) % ROSE_MODULUS; 90 } 91 92 return nr == rose->vs; 93 } 94 95 /* 96 * This routine is called when the packet layer internally generates a 97 * control frame. 98 */ 99 void rose_write_internal(struct sock *sk, int frametype) 100 { 101 struct rose_sock *rose = rose_sk(sk); 102 struct sk_buff *skb; 103 unsigned char *dptr; 104 unsigned char lci1, lci2; 105 int maxfaclen = 0; 106 int len, faclen; 107 int reserve; 108 109 reserve = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + 1; 110 len = ROSE_MIN_LEN; 111 112 switch (frametype) { 113 case ROSE_CALL_REQUEST: 114 len += 1 + ROSE_ADDR_LEN + ROSE_ADDR_LEN; 115 maxfaclen = 256; 116 break; 117 case ROSE_CALL_ACCEPTED: 118 case ROSE_CLEAR_REQUEST: 119 case ROSE_RESET_REQUEST: 120 len += 2; 121 break; 122 } 123 124 skb = alloc_skb(reserve + len + maxfaclen, GFP_ATOMIC); 125 if (!skb) 126 return; 127 128 /* 129 * Space for AX.25 header and PID. 130 */ 131 skb_reserve(skb, reserve); 132 133 dptr = skb_put(skb, len); 134 135 lci1 = (rose->lci >> 8) & 0x0F; 136 lci2 = (rose->lci >> 0) & 0xFF; 137 138 switch (frametype) { 139 case ROSE_CALL_REQUEST: 140 *dptr++ = ROSE_GFI | lci1; 141 *dptr++ = lci2; 142 *dptr++ = frametype; 143 *dptr++ = ROSE_CALL_REQ_ADDR_LEN_VAL; 144 memcpy(dptr, &rose->dest_addr, ROSE_ADDR_LEN); 145 dptr += ROSE_ADDR_LEN; 146 memcpy(dptr, &rose->source_addr, ROSE_ADDR_LEN); 147 dptr += ROSE_ADDR_LEN; 148 faclen = rose_create_facilities(dptr, rose); 149 skb_put(skb, faclen); 150 dptr += faclen; 151 break; 152 153 case ROSE_CALL_ACCEPTED: 154 *dptr++ = ROSE_GFI | lci1; 155 *dptr++ = lci2; 156 *dptr++ = frametype; 157 *dptr++ = 0x00; /* Address length */ 158 *dptr++ = 0; /* Facilities length */ 159 break; 160 161 case ROSE_CLEAR_REQUEST: 162 *dptr++ = ROSE_GFI | lci1; 163 *dptr++ = lci2; 164 *dptr++ = frametype; 165 *dptr++ = rose->cause; 166 *dptr++ = rose->diagnostic; 167 break; 168 169 case ROSE_RESET_REQUEST: 170 *dptr++ = ROSE_GFI | lci1; 171 *dptr++ = lci2; 172 *dptr++ = frametype; 173 *dptr++ = ROSE_DTE_ORIGINATED; 174 *dptr++ = 0; 175 break; 176 177 case ROSE_RR: 178 case ROSE_RNR: 179 *dptr++ = ROSE_GFI | lci1; 180 *dptr++ = lci2; 181 *dptr = frametype; 182 *dptr++ |= (rose->vr << 5) & 0xE0; 183 break; 184 185 case ROSE_CLEAR_CONFIRMATION: 186 case ROSE_RESET_CONFIRMATION: 187 *dptr++ = ROSE_GFI | lci1; 188 *dptr++ = lci2; 189 *dptr++ = frametype; 190 break; 191 192 default: 193 printk(KERN_ERR "ROSE: rose_write_internal - invalid frametype %02X\n", frametype); 194 kfree_skb(skb); 195 return; 196 } 197 198 rose_transmit_link(skb, rose->neighbour); 199 } 200 201 int rose_decode(struct sk_buff *skb, int *ns, int *nr, int *q, int *d, int *m) 202 { 203 unsigned char *frame; 204 205 frame = skb->data; 206 207 *ns = *nr = *q = *d = *m = 0; 208 209 switch (frame[2]) { 210 case ROSE_CALL_REQUEST: 211 case ROSE_CALL_ACCEPTED: 212 case ROSE_CLEAR_REQUEST: 213 case ROSE_CLEAR_CONFIRMATION: 214 case ROSE_RESET_REQUEST: 215 case ROSE_RESET_CONFIRMATION: 216 return frame[2]; 217 default: 218 break; 219 } 220 221 if ((frame[2] & 0x1F) == ROSE_RR || 222 (frame[2] & 0x1F) == ROSE_RNR) { 223 *nr = (frame[2] >> 5) & 0x07; 224 return frame[2] & 0x1F; 225 } 226 227 if ((frame[2] & 0x01) == ROSE_DATA) { 228 *q = (frame[0] & ROSE_Q_BIT) == ROSE_Q_BIT; 229 *d = (frame[0] & ROSE_D_BIT) == ROSE_D_BIT; 230 *m = (frame[2] & ROSE_M_BIT) == ROSE_M_BIT; 231 *nr = (frame[2] >> 5) & 0x07; 232 *ns = (frame[2] >> 1) & 0x07; 233 return ROSE_DATA; 234 } 235 236 return ROSE_ILLEGAL; 237 } 238 239 static int rose_parse_national(unsigned char *p, struct rose_facilities_struct *facilities, int len) 240 { 241 unsigned char *pt; 242 unsigned char l, lg, n = 0; 243 int fac_national_digis_received = 0; 244 245 do { 246 switch (*p & 0xC0) { 247 case 0x00: 248 if (len < 2) 249 return -1; 250 p += 2; 251 n += 2; 252 len -= 2; 253 break; 254 255 case 0x40: 256 if (len < 3) 257 return -1; 258 if (*p == FAC_NATIONAL_RAND) 259 facilities->rand = ((p[1] << 8) & 0xFF00) + ((p[2] << 0) & 0x00FF); 260 p += 3; 261 n += 3; 262 len -= 3; 263 break; 264 265 case 0x80: 266 if (len < 4) 267 return -1; 268 p += 4; 269 n += 4; 270 len -= 4; 271 break; 272 273 case 0xC0: 274 if (len < 2) 275 return -1; 276 l = p[1]; 277 if (len < 2 + l) 278 return -1; 279 if (*p == FAC_NATIONAL_DEST_DIGI) { 280 if (!fac_national_digis_received) { 281 if (l < AX25_ADDR_LEN) 282 return -1; 283 memcpy(&facilities->source_digis[0], p + 2, AX25_ADDR_LEN); 284 facilities->source_ndigis = 1; 285 } 286 } 287 else if (*p == FAC_NATIONAL_SRC_DIGI) { 288 if (!fac_national_digis_received) { 289 if (l < AX25_ADDR_LEN) 290 return -1; 291 memcpy(&facilities->dest_digis[0], p + 2, AX25_ADDR_LEN); 292 facilities->dest_ndigis = 1; 293 } 294 } 295 else if (*p == FAC_NATIONAL_FAIL_CALL) { 296 if (l < AX25_ADDR_LEN) 297 return -1; 298 memcpy(&facilities->fail_call, p + 2, AX25_ADDR_LEN); 299 } 300 else if (*p == FAC_NATIONAL_FAIL_ADD) { 301 if (l < 1 + ROSE_ADDR_LEN) 302 return -1; 303 memcpy(&facilities->fail_addr, p + 3, ROSE_ADDR_LEN); 304 } 305 else if (*p == FAC_NATIONAL_DIGIS) { 306 if (l % AX25_ADDR_LEN) 307 return -1; 308 fac_national_digis_received = 1; 309 facilities->source_ndigis = 0; 310 facilities->dest_ndigis = 0; 311 for (pt = p + 2, lg = 0 ; lg < l ; pt += AX25_ADDR_LEN, lg += AX25_ADDR_LEN) { 312 if (pt[6] & AX25_HBIT) { 313 if (facilities->dest_ndigis >= ROSE_MAX_DIGIS) 314 return -1; 315 memcpy(&facilities->dest_digis[facilities->dest_ndigis++], pt, AX25_ADDR_LEN); 316 } else { 317 if (facilities->source_ndigis >= ROSE_MAX_DIGIS) 318 return -1; 319 memcpy(&facilities->source_digis[facilities->source_ndigis++], pt, AX25_ADDR_LEN); 320 } 321 } 322 } 323 p += l + 2; 324 n += l + 2; 325 len -= l + 2; 326 break; 327 } 328 } while (*p != 0x00 && len > 0); 329 330 return n; 331 } 332 333 static int rose_parse_ccitt(unsigned char *p, struct rose_facilities_struct *facilities, int len) 334 { 335 unsigned char l, n = 0; 336 char callsign[11]; 337 338 do { 339 switch (*p & 0xC0) { 340 case 0x00: 341 if (len < 2) 342 return -1; 343 p += 2; 344 n += 2; 345 len -= 2; 346 break; 347 348 case 0x40: 349 if (len < 3) 350 return -1; 351 p += 3; 352 n += 3; 353 len -= 3; 354 break; 355 356 case 0x80: 357 if (len < 4) 358 return -1; 359 p += 4; 360 n += 4; 361 len -= 4; 362 break; 363 364 case 0xC0: 365 if (len < 2) 366 return -1; 367 l = p[1]; 368 369 /* Prevent overflows*/ 370 if (l < 10 || l > 20) 371 return -1; 372 373 if (*p == FAC_CCITT_DEST_NSAP) { 374 memcpy(&facilities->source_addr, p + 7, ROSE_ADDR_LEN); 375 memcpy(callsign, p + 12, l - 10); 376 callsign[l - 10] = '\0'; 377 asc2ax(&facilities->source_call, callsign); 378 } 379 if (*p == FAC_CCITT_SRC_NSAP) { 380 memcpy(&facilities->dest_addr, p + 7, ROSE_ADDR_LEN); 381 memcpy(callsign, p + 12, l - 10); 382 callsign[l - 10] = '\0'; 383 asc2ax(&facilities->dest_call, callsign); 384 } 385 p += l + 2; 386 n += l + 2; 387 len -= l + 2; 388 break; 389 } 390 } while (*p != 0x00 && len > 0); 391 392 return n; 393 } 394 395 int rose_parse_facilities(unsigned char *p, unsigned packet_len, 396 struct rose_facilities_struct *facilities) 397 { 398 int facilities_len, len; 399 400 facilities_len = *p++; 401 402 if (facilities_len == 0 || (unsigned int)facilities_len > packet_len) 403 return 0; 404 405 while (facilities_len >= 3 && *p == 0x00) { 406 facilities_len--; 407 p++; 408 409 switch (*p) { 410 case FAC_NATIONAL: /* National */ 411 len = rose_parse_national(p + 1, facilities, facilities_len - 1); 412 break; 413 414 case FAC_CCITT: /* CCITT */ 415 len = rose_parse_ccitt(p + 1, facilities, facilities_len - 1); 416 break; 417 418 default: 419 printk(KERN_DEBUG "ROSE: rose_parse_facilities - unknown facilities family %02X\n", *p); 420 len = 1; 421 break; 422 } 423 424 if (len < 0) 425 return 0; 426 if (WARN_ON(len >= facilities_len)) 427 return 0; 428 facilities_len -= len + 1; 429 p += len + 1; 430 } 431 432 return facilities_len == 0; 433 } 434 435 static int rose_create_facilities(unsigned char *buffer, struct rose_sock *rose) 436 { 437 unsigned char *p = buffer + 1; 438 char *callsign; 439 char buf[11]; 440 int len, nb; 441 442 /* National Facilities */ 443 if (rose->rand != 0 || rose->source_ndigis == 1 || rose->dest_ndigis == 1) { 444 *p++ = 0x00; 445 *p++ = FAC_NATIONAL; 446 447 if (rose->rand != 0) { 448 *p++ = FAC_NATIONAL_RAND; 449 *p++ = (rose->rand >> 8) & 0xFF; 450 *p++ = (rose->rand >> 0) & 0xFF; 451 } 452 453 /* Sent before older facilities */ 454 if ((rose->source_ndigis > 0) || (rose->dest_ndigis > 0)) { 455 int maxdigi = 0; 456 *p++ = FAC_NATIONAL_DIGIS; 457 *p++ = AX25_ADDR_LEN * (rose->source_ndigis + rose->dest_ndigis); 458 for (nb = 0 ; nb < rose->source_ndigis ; nb++) { 459 if (++maxdigi >= ROSE_MAX_DIGIS) 460 break; 461 memcpy(p, &rose->source_digis[nb], AX25_ADDR_LEN); 462 p[6] |= AX25_HBIT; 463 p += AX25_ADDR_LEN; 464 } 465 for (nb = 0 ; nb < rose->dest_ndigis ; nb++) { 466 if (++maxdigi >= ROSE_MAX_DIGIS) 467 break; 468 memcpy(p, &rose->dest_digis[nb], AX25_ADDR_LEN); 469 p[6] &= ~AX25_HBIT; 470 p += AX25_ADDR_LEN; 471 } 472 } 473 474 /* For compatibility */ 475 if (rose->source_ndigis > 0) { 476 *p++ = FAC_NATIONAL_SRC_DIGI; 477 *p++ = AX25_ADDR_LEN; 478 memcpy(p, &rose->source_digis[0], AX25_ADDR_LEN); 479 p += AX25_ADDR_LEN; 480 } 481 482 /* For compatibility */ 483 if (rose->dest_ndigis > 0) { 484 *p++ = FAC_NATIONAL_DEST_DIGI; 485 *p++ = AX25_ADDR_LEN; 486 memcpy(p, &rose->dest_digis[0], AX25_ADDR_LEN); 487 p += AX25_ADDR_LEN; 488 } 489 } 490 491 *p++ = 0x00; 492 *p++ = FAC_CCITT; 493 494 *p++ = FAC_CCITT_DEST_NSAP; 495 496 callsign = ax2asc(buf, &rose->dest_call); 497 498 *p++ = strlen(callsign) + 10; 499 *p++ = (strlen(callsign) + 9) * 2; /* ??? */ 500 501 *p++ = 0x47; *p++ = 0x00; *p++ = 0x11; 502 *p++ = ROSE_ADDR_LEN * 2; 503 memcpy(p, &rose->dest_addr, ROSE_ADDR_LEN); 504 p += ROSE_ADDR_LEN; 505 506 memcpy(p, callsign, strlen(callsign)); 507 p += strlen(callsign); 508 509 *p++ = FAC_CCITT_SRC_NSAP; 510 511 callsign = ax2asc(buf, &rose->source_call); 512 513 *p++ = strlen(callsign) + 10; 514 *p++ = (strlen(callsign) + 9) * 2; /* ??? */ 515 516 *p++ = 0x47; *p++ = 0x00; *p++ = 0x11; 517 *p++ = ROSE_ADDR_LEN * 2; 518 memcpy(p, &rose->source_addr, ROSE_ADDR_LEN); 519 p += ROSE_ADDR_LEN; 520 521 memcpy(p, callsign, strlen(callsign)); 522 p += strlen(callsign); 523 524 len = p - buffer; 525 buffer[0] = len - 1; 526 527 return len; 528 } 529 530 void rose_disconnect(struct sock *sk, int reason, int cause, int diagnostic) 531 { 532 struct rose_sock *rose = rose_sk(sk); 533 534 rose_stop_timer(sk); 535 rose_stop_idletimer(sk); 536 537 rose_clear_queues(sk); 538 539 rose->lci = 0; 540 rose->state = ROSE_STATE_0; 541 542 if (cause != -1) 543 rose->cause = cause; 544 545 if (diagnostic != -1) 546 rose->diagnostic = diagnostic; 547 548 sk->sk_state = TCP_CLOSE; 549 sk->sk_err = reason; 550 sk->sk_shutdown |= SEND_SHUTDOWN; 551 552 if (!sock_flag(sk, SOCK_DEAD)) { 553 sk->sk_state_change(sk); 554 sock_set_flag(sk, SOCK_DEAD); 555 } 556 } 557