1272343Sngie/* $OpenBSD: parse.c,v 1.11 2004/05/05 23:07:47 deraadt Exp $ */ 2272343Sngie 3272343Sngie/* Common parser code for dhcpd and dhclient. */ 4272343Sngie 5272343Sngie/* 6272343Sngie * Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium. 7272343Sngie * All rights reserved. 8272343Sngie * 9272343Sngie * Redistribution and use in source and binary forms, with or without 10272343Sngie * modification, are permitted provided that the following conditions 11272343Sngie * are met: 12272343Sngie * 13272343Sngie * 1. Redistributions of source code must retain the above copyright 14272343Sngie * notice, this list of conditions and the following disclaimer. 15272343Sngie * 2. Redistributions in binary form must reproduce the above copyright 16272343Sngie * notice, this list of conditions and the following disclaimer in the 17272343Sngie * documentation and/or other materials provided with the distribution. 18272343Sngie * 3. Neither the name of The Internet Software Consortium nor the names 19272343Sngie * of its contributors may be used to endorse or promote products derived 20272343Sngie * from this software without specific prior written permission. 21272343Sngie * 22272343Sngie * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND 23272343Sngie * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 24272343Sngie * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 25272343Sngie * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 26272343Sngie * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR 27272343Sngie * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28272343Sngie * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 29272343Sngie * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 30272343Sngie * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 31272343Sngie * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 32272343Sngie * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 33272343Sngie * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34272343Sngie * SUCH DAMAGE. 35272343Sngie * 36272343Sngie * This software has been written for the Internet Software Consortium 37272343Sngie * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie 38272343Sngie * Enterprises. To learn more about the Internet Software Consortium, 39272343Sngie * see ``http://www.vix.com/isc''. To learn more about Vixie 40272343Sngie * Enterprises, see ``http://www.vix.com''. 41272343Sngie */ 42272343Sngie 43272343Sngie#include <sys/cdefs.h> 44272343Sngie__FBSDID("$FreeBSD: releng/11.0/sbin/dhclient/parse.c 228615 2011-12-17 01:29:46Z dim $"); 45272343Sngie 46272343Sngie#include "dhcpd.h" 47272343Sngie#include "dhctoken.h" 48272343Sngie 49272343Sngie/* Skip to the semicolon ending the current statement. If we encounter 50272343Sngie * braces, the matching closing brace terminates the statement. If we 51272343Sngie * encounter a right brace but haven't encountered a left brace, return 52272343Sngie * leaving the brace in the token buffer for the caller. If we see a 53272343Sngie * semicolon and haven't seen a left brace, return. This lets us skip 54272343Sngie * over: 55272343Sngie * 56272343Sngie * statement; 57272343Sngie * statement foo bar { } 58272343Sngie * statement foo bar { statement { } } 59272343Sngie * statement} 60272343Sngie * 61272343Sngie * ...et cetera. 62272343Sngie */ 63272343Sngievoid 64272343Sngieskip_to_semi(FILE *cfile) 65272343Sngie{ 66272343Sngie int brace_count = 0, token; 67272343Sngie char *val; 68272343Sngie 69272343Sngie do { 70272343Sngie token = peek_token(&val, cfile); 71272343Sngie if (token == RBRACE) { 72272343Sngie if (brace_count) { 73272343Sngie token = next_token(&val, cfile); 74272343Sngie if (!--brace_count) 75272343Sngie return; 76272343Sngie } else 77272343Sngie return; 78272343Sngie } else if (token == LBRACE) { 79272343Sngie brace_count++; 80272343Sngie } else if (token == SEMI && !brace_count) { 81272343Sngie token = next_token(&val, cfile); 82272343Sngie return; 83272343Sngie } else if (token == '\n') { 84272343Sngie /* 85272343Sngie * EOL only happens when parsing 86272343Sngie * /etc/resolv.conf, and we treat it like a 87272343Sngie * semicolon because the resolv.conf file is 88272343Sngie * line-oriented. 89272343Sngie */ 90272343Sngie token = next_token(&val, cfile); 91272343Sngie return; 92272343Sngie } 93272343Sngie token = next_token(&val, cfile); 94272343Sngie } while (token != EOF); 95272343Sngie} 96272343Sngie 97272343Sngieint 98272343Sngieparse_semi(FILE *cfile) 99272343Sngie{ 100272343Sngie int token; 101272343Sngie char *val; 102272343Sngie 103272343Sngie token = next_token(&val, cfile); 104272343Sngie if (token != SEMI) { 105272343Sngie parse_warn("semicolon expected."); 106272343Sngie skip_to_semi(cfile); 107272343Sngie return (0); 108272343Sngie } 109272343Sngie return (1); 110272343Sngie} 111272343Sngie 112272343Sngie/* 113272343Sngie * string-parameter :== STRING SEMI 114272343Sngie */ 115272343Sngiechar * 116272343Sngieparse_string(FILE *cfile) 117272343Sngie{ 118272343Sngie char *val, *s; 119272343Sngie size_t valsize; 120272343Sngie int token; 121272343Sngie 122272343Sngie token = next_token(&val, cfile); 123272343Sngie if (token != STRING) { 124272343Sngie parse_warn("filename must be a string"); 125272343Sngie skip_to_semi(cfile); 126272343Sngie return (NULL); 127272343Sngie } 128272343Sngie valsize = strlen(val) + 1; 129272343Sngie s = malloc(valsize); 130272343Sngie if (!s) 131272343Sngie error("no memory for string %s.", val); 132272343Sngie memcpy(s, val, valsize); 133272343Sngie 134272343Sngie if (!parse_semi(cfile)) 135272343Sngie return (NULL); 136272343Sngie return (s); 137272343Sngie} 138272343Sngie 139272343Sngieint 140272343Sngieparse_ip_addr(FILE *cfile, struct iaddr *addr) 141272343Sngie{ 142272343Sngie addr->len = 4; 143272343Sngie if (parse_numeric_aggregate(cfile, addr->iabuf, 144272343Sngie &addr->len, DOT, 10, 8)) 145272343Sngie return (1); 146272343Sngie return (0); 147272343Sngie} 148272343Sngie 149272343Sngie/* 150272343Sngie * hardware-parameter :== HARDWARE ETHERNET csns SEMI 151272343Sngie * csns :== NUMBER | csns COLON NUMBER 152272343Sngie */ 153272343Sngievoid 154272343Sngieparse_hardware_param(FILE *cfile, struct hardware *hardware) 155272343Sngie{ 156272343Sngie unsigned char *t; 157272343Sngie int token, hlen; 158272343Sngie char *val; 159272343Sngie 160272343Sngie token = next_token(&val, cfile); 161272343Sngie switch (token) { 162272343Sngie case ETHERNET: 163272343Sngie hardware->htype = HTYPE_ETHER; 164272343Sngie break; 165272343Sngie case TOKEN_RING: 166272343Sngie hardware->htype = HTYPE_IEEE802; 167272343Sngie break; 168272343Sngie case FDDI: 169272343Sngie hardware->htype = HTYPE_FDDI; 170272343Sngie break; 171272343Sngie default: 172272343Sngie parse_warn("expecting a network hardware type"); 173272343Sngie skip_to_semi(cfile); 174272343Sngie return; 175272343Sngie } 176272343Sngie 177272343Sngie /* 178272343Sngie * Parse the hardware address information. Technically, it 179272343Sngie * would make a lot of sense to restrict the length of the data 180272343Sngie * we'll accept here to the length of a particular hardware 181272343Sngie * address type. Unfortunately, there are some broken clients 182272343Sngie * out there that put bogus data in the chaddr buffer, and we 183272343Sngie * accept that data in the lease file rather than simply failing 184272343Sngie * on such clients. Yuck. 185272343Sngie */ 186272343Sngie hlen = 0; 187272343Sngie t = parse_numeric_aggregate(cfile, NULL, &hlen, COLON, 16, 8); 188272343Sngie if (!t) 189272343Sngie return; 190272343Sngie if (hlen > sizeof(hardware->haddr)) { 191272343Sngie free(t); 192272343Sngie parse_warn("hardware address too long"); 193272343Sngie } else { 194272343Sngie hardware->hlen = hlen; 195272343Sngie memcpy((unsigned char *)&hardware->haddr[0], t, 196272343Sngie hardware->hlen); 197272343Sngie if (hlen < sizeof(hardware->haddr)) 198272343Sngie memset(&hardware->haddr[hlen], 0, 199272343Sngie sizeof(hardware->haddr) - hlen); 200272343Sngie free(t); 201272343Sngie } 202272343Sngie 203272343Sngie token = next_token(&val, cfile); 204272343Sngie if (token != SEMI) { 205272343Sngie parse_warn("expecting semicolon."); 206272343Sngie skip_to_semi(cfile); 207272343Sngie } 208272343Sngie} 209272343Sngie 210272343Sngie/* 211272343Sngie * lease-time :== NUMBER SEMI 212272343Sngie */ 213272343Sngievoid 214272343Sngieparse_lease_time(FILE *cfile, time_t *timep) 215272343Sngie{ 216272343Sngie char *val; 217272343Sngie int token; 218272343Sngie 219272343Sngie token = next_token(&val, cfile); 220272343Sngie if (token != NUMBER) { 221272343Sngie parse_warn("Expecting numeric lease time"); 222272343Sngie skip_to_semi(cfile); 223272343Sngie return; 224272343Sngie } 225272343Sngie convert_num((unsigned char *)timep, val, 10, 32); 226272343Sngie /* Unswap the number - convert_num returns stuff in NBO. */ 227272343Sngie *timep = ntohl(*timep); /* XXX */ 228272343Sngie 229272343Sngie parse_semi(cfile); 230272343Sngie} 231272343Sngie 232272343Sngie/* 233272343Sngie * No BNF for numeric aggregates - that's defined by the caller. What 234272343Sngie * this function does is to parse a sequence of numbers separated by the 235272343Sngie * token specified in separator. If max is zero, any number of numbers 236272343Sngie * will be parsed; otherwise, exactly max numbers are expected. Base 237272343Sngie * and size tell us how to internalize the numbers once they've been 238272343Sngie * tokenized. 239272343Sngie */ 240272343Sngieunsigned char * 241272343Sngieparse_numeric_aggregate(FILE *cfile, unsigned char *buf, int *max, 242272343Sngie int separator, int base, int size) 243272343Sngie{ 244272343Sngie unsigned char *bufp = buf, *s = NULL; 245 int token, count = 0; 246 char *val, *t; 247 size_t valsize; 248 pair c = NULL; 249 250 if (!bufp && *max) { 251 bufp = malloc(*max * size / 8); 252 if (!bufp) 253 error("can't allocate space for numeric aggregate"); 254 } else 255 s = bufp; 256 257 do { 258 if (count) { 259 token = peek_token(&val, cfile); 260 if (token != separator) { 261 if (!*max) 262 break; 263 if (token != RBRACE && token != LBRACE) 264 token = next_token(&val, cfile); 265 parse_warn("too few numbers."); 266 if (token != SEMI) 267 skip_to_semi(cfile); 268 return (NULL); 269 } 270 token = next_token(&val, cfile); 271 } 272 token = next_token(&val, cfile); 273 274 if (token == EOF) { 275 parse_warn("unexpected end of file"); 276 break; 277 } 278 279 /* Allow NUMBER_OR_NAME if base is 16. */ 280 if (token != NUMBER && 281 (base != 16 || token != NUMBER_OR_NAME)) { 282 parse_warn("expecting numeric value."); 283 skip_to_semi(cfile); 284 return (NULL); 285 } 286 /* 287 * If we can, convert the number now; otherwise, build a 288 * linked list of all the numbers. 289 */ 290 if (s) { 291 convert_num(s, val, base, size); 292 s += size / 8; 293 } else { 294 valsize = strlen(val) + 1; 295 t = malloc(valsize); 296 if (!t) 297 error("no temp space for number."); 298 memcpy(t, val, valsize); 299 c = cons(t, c); 300 } 301 } while (++count != *max); 302 303 /* If we had to cons up a list, convert it now. */ 304 if (c) { 305 bufp = malloc(count * size / 8); 306 if (!bufp) 307 error("can't allocate space for numeric aggregate."); 308 s = bufp + count - size / 8; 309 *max = count; 310 } 311 while (c) { 312 pair cdr = c->cdr; 313 convert_num(s, (char *)c->car, base, size); 314 s -= size / 8; 315 /* Free up temp space. */ 316 free(c->car); 317 free(c); 318 c = cdr; 319 } 320 return (bufp); 321} 322 323void 324convert_num(unsigned char *buf, char *str, int base, int size) 325{ 326 int negative = 0, tval, max; 327 u_int32_t val = 0; 328 char *ptr = str; 329 330 if (*ptr == '-') { 331 negative = 1; 332 ptr++; 333 } 334 335 /* If base wasn't specified, figure it out from the data. */ 336 if (!base) { 337 if (ptr[0] == '0') { 338 if (ptr[1] == 'x') { 339 base = 16; 340 ptr += 2; 341 } else if (isascii(ptr[1]) && isdigit(ptr[1])) { 342 base = 8; 343 ptr += 1; 344 } else 345 base = 10; 346 } else 347 base = 10; 348 } 349 350 do { 351 tval = *ptr++; 352 /* XXX assumes ASCII... */ 353 if (tval >= 'a') 354 tval = tval - 'a' + 10; 355 else if (tval >= 'A') 356 tval = tval - 'A' + 10; 357 else if (tval >= '0') 358 tval -= '0'; 359 else { 360 warning("Bogus number: %s.", str); 361 break; 362 } 363 if (tval >= base) { 364 warning("Bogus number: %s: digit %d not in base %d", 365 str, tval, base); 366 break; 367 } 368 val = val * base + tval; 369 } while (*ptr); 370 371 if (negative) 372 max = (1 << (size - 1)); 373 else 374 max = (1 << (size - 1)) + ((1 << (size - 1)) - 1); 375 if (val > max) { 376 switch (base) { 377 case 8: 378 warning("value %s%o exceeds max (%d) for precision.", 379 negative ? "-" : "", val, max); 380 break; 381 case 16: 382 warning("value %s%x exceeds max (%d) for precision.", 383 negative ? "-" : "", val, max); 384 break; 385 default: 386 warning("value %s%u exceeds max (%d) for precision.", 387 negative ? "-" : "", val, max); 388 break; 389 } 390 } 391 392 if (negative) 393 switch (size) { 394 case 8: 395 *buf = -(unsigned long)val; 396 break; 397 case 16: 398 putShort(buf, -(unsigned long)val); 399 break; 400 case 32: 401 putLong(buf, -(unsigned long)val); 402 break; 403 default: 404 warning("Unexpected integer size: %d", size); 405 break; 406 } 407 else 408 switch (size) { 409 case 8: 410 *buf = (u_int8_t)val; 411 break; 412 case 16: 413 putUShort(buf, (u_int16_t)val); 414 break; 415 case 32: 416 putULong(buf, val); 417 break; 418 default: 419 warning("Unexpected integer size: %d", size); 420 break; 421 } 422} 423 424/* 425 * date :== NUMBER NUMBER SLASH NUMBER SLASH NUMBER 426 * NUMBER COLON NUMBER COLON NUMBER SEMI 427 * 428 * Dates are always in GMT; first number is day of week; next is 429 * year/month/day; next is hours:minutes:seconds on a 24-hour 430 * clock. 431 */ 432time_t 433parse_date(FILE *cfile) 434{ 435 static int months[11] = { 31, 59, 90, 120, 151, 181, 436 212, 243, 273, 304, 334 }; 437 int guess, token; 438 struct tm tm; 439 char *val; 440 441 /* Day of week... */ 442 token = next_token(&val, cfile); 443 if (token != NUMBER) { 444 parse_warn("numeric day of week expected."); 445 if (token != SEMI) 446 skip_to_semi(cfile); 447 return (0); 448 } 449 tm.tm_wday = atoi(val); 450 451 /* Year... */ 452 token = next_token(&val, cfile); 453 if (token != NUMBER) { 454 parse_warn("numeric year expected."); 455 if (token != SEMI) 456 skip_to_semi(cfile); 457 return (0); 458 } 459 tm.tm_year = atoi(val); 460 if (tm.tm_year > 1900) 461 tm.tm_year -= 1900; 462 463 /* Slash separating year from month... */ 464 token = next_token(&val, cfile); 465 if (token != SLASH) { 466 parse_warn("expected slash separating year from month."); 467 if (token != SEMI) 468 skip_to_semi(cfile); 469 return (0); 470 } 471 472 /* Month... */ 473 token = next_token(&val, cfile); 474 if (token != NUMBER) { 475 parse_warn("numeric month expected."); 476 if (token != SEMI) 477 skip_to_semi(cfile); 478 return (0); 479 } 480 tm.tm_mon = atoi(val) - 1; 481 482 /* Slash separating month from day... */ 483 token = next_token(&val, cfile); 484 if (token != SLASH) { 485 parse_warn("expected slash separating month from day."); 486 if (token != SEMI) 487 skip_to_semi(cfile); 488 return (0); 489 } 490 491 /* Month... */ 492 token = next_token(&val, cfile); 493 if (token != NUMBER) { 494 parse_warn("numeric day of month expected."); 495 if (token != SEMI) 496 skip_to_semi(cfile); 497 return (0); 498 } 499 tm.tm_mday = atoi(val); 500 501 /* Hour... */ 502 token = next_token(&val, cfile); 503 if (token != NUMBER) { 504 parse_warn("numeric hour expected."); 505 if (token != SEMI) 506 skip_to_semi(cfile); 507 return (0); 508 } 509 tm.tm_hour = atoi(val); 510 511 /* Colon separating hour from minute... */ 512 token = next_token(&val, cfile); 513 if (token != COLON) { 514 parse_warn("expected colon separating hour from minute."); 515 if (token != SEMI) 516 skip_to_semi(cfile); 517 return (0); 518 } 519 520 /* Minute... */ 521 token = next_token(&val, cfile); 522 if (token != NUMBER) { 523 parse_warn("numeric minute expected."); 524 if (token != SEMI) 525 skip_to_semi(cfile); 526 return (0); 527 } 528 tm.tm_min = atoi(val); 529 530 /* Colon separating minute from second... */ 531 token = next_token(&val, cfile); 532 if (token != COLON) { 533 parse_warn("expected colon separating hour from minute."); 534 if (token != SEMI) 535 skip_to_semi(cfile); 536 return (0); 537 } 538 539 /* Minute... */ 540 token = next_token(&val, cfile); 541 if (token != NUMBER) { 542 parse_warn("numeric minute expected."); 543 if (token != SEMI) 544 skip_to_semi(cfile); 545 return (0); 546 } 547 tm.tm_sec = atoi(val); 548 tm.tm_isdst = 0; 549 550 /* XXX: We assume that mktime does not use tm_yday. */ 551 tm.tm_yday = 0; 552 553 /* Make sure the date ends in a semicolon... */ 554 token = next_token(&val, cfile); 555 if (token != SEMI) { 556 parse_warn("semicolon expected."); 557 skip_to_semi(cfile); 558 return (0); 559 } 560 561 /* Guess the time value... */ 562 guess = ((((((365 * (tm.tm_year - 70) + /* Days in years since '70 */ 563 (tm.tm_year - 69) / 4 + /* Leap days since '70 */ 564 (tm.tm_mon /* Days in months this year */ 565 ? months[tm.tm_mon - 1] 566 : 0) + 567 (tm.tm_mon > 1 && /* Leap day this year */ 568 !((tm.tm_year - 72) & 3)) + 569 tm.tm_mday - 1) * 24) + /* Day of month */ 570 tm.tm_hour) * 60) + 571 tm.tm_min) * 60) + tm.tm_sec; 572 573 /* 574 * This guess could be wrong because of leap seconds or other 575 * weirdness we don't know about that the system does. For 576 * now, we're just going to accept the guess, but at some point 577 * it might be nice to do a successive approximation here to get 578 * an exact value. Even if the error is small, if the server 579 * is restarted frequently (and thus the lease database is 580 * reread), the error could accumulate into something 581 * significant. 582 */ 583 return (guess); 584} 585