1 /* $NetBSD: getcap.c,v 1.29 1999/03/29 09:27:29 abs Exp $ */ 2 3 /*- 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Casey Leedom of Lawrence Livermore National Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifdef HAVE_CONFIG_H 36 #include <config.h> 37 #endif 38 #include "roken.h" 39 RCSID("$Id: getcap.c 22071 2007-11-14 20:04:50Z lha $"); 40 41 #include <sys/types.h> 42 #include <ctype.h> 43 #if defined(HAVE_DB_185_H) 44 #include <db_185.h> 45 #elif defined(HAVE_DB_H) 46 #include <db.h> 47 #endif 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <limits.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #define BFRAG 1024 57 #if 0 58 #define BSIZE 1024 59 #endif 60 #define ESC ('[' & 037) /* ASCII ESC */ 61 #define MAX_RECURSION 32 /* maximum getent recursion */ 62 #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */ 63 64 #define RECOK (char)0 65 #define TCERR (char)1 66 #define SHADOW (char)2 67 68 static size_t topreclen; /* toprec length */ 69 static char *toprec; /* Additional record specified by cgetset() */ 70 static int gottoprec; /* Flag indicating retrieval of toprecord */ 71 72 #if 0 /* 73 * Don't use db support unless it's build into libc but we don't 74 * check for that now, so just disable the code. 75 */ 76 #if defined(HAVE_DBOPEN) && defined(HAVE_DB_H) 77 #define USE_DB 78 #endif 79 #endif 80 81 #ifdef USE_DB 82 static int cdbget (DB *, char **, const char *); 83 #endif 84 static int getent (char **, size_t *, char **, int, const char *, int, char *); 85 static int nfcmp (char *, char *); 86 87 88 int ROKEN_LIB_FUNCTION cgetset(const char *ent); 89 char *ROKEN_LIB_FUNCTION cgetcap(char *buf, const char *cap, int type); 90 int ROKEN_LIB_FUNCTION cgetent(char **buf, char **db_array, const char *name); 91 int ROKEN_LIB_FUNCTION cgetmatch(const char *buf, const char *name); 92 int ROKEN_LIB_FUNCTION cgetclose(void); 93 #if 0 94 int cgetfirst(char **buf, char **db_array); 95 int cgetnext(char **bp, char **db_array); 96 #endif 97 int ROKEN_LIB_FUNCTION cgetstr(char *buf, const char *cap, char **str); 98 int ROKEN_LIB_FUNCTION cgetustr(char *buf, const char *cap, char **str); 99 int ROKEN_LIB_FUNCTION cgetnum(char *buf, const char *cap, long *num); 100 /* 101 * Cgetset() allows the addition of a user specified buffer to be added 102 * to the database array, in effect "pushing" the buffer on top of the 103 * virtual database. 0 is returned on success, -1 on failure. 104 */ 105 int ROKEN_LIB_FUNCTION 106 cgetset(const char *ent) 107 { 108 const char *source, *check; 109 char *dest; 110 111 if (ent == NULL) { 112 if (toprec) 113 free(toprec); 114 toprec = NULL; 115 topreclen = 0; 116 return (0); 117 } 118 topreclen = strlen(ent); 119 if ((toprec = malloc (topreclen + 1)) == NULL) { 120 errno = ENOMEM; 121 return (-1); 122 } 123 gottoprec = 0; 124 125 source=ent; 126 dest=toprec; 127 while (*source) { /* Strip whitespace */ 128 *dest++ = *source++; /* Do not check first field */ 129 while (*source == ':') { 130 check=source+1; 131 while (*check && (isspace((unsigned char)*check) || 132 (*check=='\\' && isspace((unsigned char)check[1])))) 133 ++check; 134 if( *check == ':' ) 135 source=check; 136 else 137 break; 138 139 } 140 } 141 *dest=0; 142 143 return (0); 144 } 145 146 /* 147 * Cgetcap searches the capability record buf for the capability cap with 148 * type `type'. A pointer to the value of cap is returned on success, NULL 149 * if the requested capability couldn't be found. 150 * 151 * Specifying a type of ':' means that nothing should follow cap (:cap:). 152 * In this case a pointer to the terminating ':' or NUL will be returned if 153 * cap is found. 154 * 155 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator) 156 * return NULL. 157 */ 158 char * ROKEN_LIB_FUNCTION 159 cgetcap(char *buf, const char *cap, int type) 160 { 161 char *bp; 162 const char *cp; 163 164 bp = buf; 165 for (;;) { 166 /* 167 * Skip past the current capability field - it's either the 168 * name field if this is the first time through the loop, or 169 * the remainder of a field whose name failed to match cap. 170 */ 171 for (;;) 172 if (*bp == '\0') 173 return (NULL); 174 else 175 if (*bp++ == ':') 176 break; 177 178 /* 179 * Try to match (cap, type) in buf. 180 */ 181 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++) 182 continue; 183 if (*cp != '\0') 184 continue; 185 if (*bp == '@') 186 return (NULL); 187 if (type == ':') { 188 if (*bp != '\0' && *bp != ':') 189 continue; 190 return(bp); 191 } 192 if (*bp != type) 193 continue; 194 bp++; 195 return (*bp == '@' ? NULL : bp); 196 } 197 /* NOTREACHED */ 198 } 199 200 /* 201 * Cgetent extracts the capability record name from the NULL terminated file 202 * array db_array and returns a pointer to a malloc'd copy of it in buf. 203 * Buf must be retained through all subsequent calls to cgetcap, cgetnum, 204 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success, 205 * -1 if the requested record couldn't be found, -2 if a system error was 206 * encountered (couldn't open/read a file, etc.), and -3 if a potential 207 * reference loop is detected. 208 */ 209 int ROKEN_LIB_FUNCTION 210 cgetent(char **buf, char **db_array, const char *name) 211 { 212 size_t dummy; 213 214 return (getent(buf, &dummy, db_array, -1, name, 0, NULL)); 215 } 216 217 /* 218 * Getent implements the functions of cgetent. If fd is non-negative, 219 * *db_array has already been opened and fd is the open file descriptor. We 220 * do this to save time and avoid using up file descriptors for tc= 221 * recursions. 222 * 223 * Getent returns the same success/failure codes as cgetent. On success, a 224 * pointer to a malloc'ed capability record with all tc= capabilities fully 225 * expanded and its length (not including trailing ASCII NUL) are left in 226 * *cap and *len. 227 * 228 * Basic algorithm: 229 * + Allocate memory incrementally as needed in chunks of size BFRAG 230 * for capability buffer. 231 * + Recurse for each tc=name and interpolate result. Stop when all 232 * names interpolated, a name can't be found, or depth exceeds 233 * MAX_RECURSION. 234 */ 235 static int 236 getent(char **cap, size_t *len, char **db_array, int fd, 237 const char *name, int depth, char *nfield) 238 { 239 char *r_end, *rp = NULL, **db_p; /* pacify gcc */ 240 int myfd = 0, eof, foundit; 241 char *record; 242 int tc_not_resolved; 243 244 /* 245 * Return with ``loop detected'' error if we've recursed more than 246 * MAX_RECURSION times. 247 */ 248 if (depth > MAX_RECURSION) 249 return (-3); 250 251 /* 252 * Check if we have a top record from cgetset(). 253 */ 254 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) { 255 size_t len = topreclen + BFRAG; 256 if ((record = malloc (len)) == NULL) { 257 errno = ENOMEM; 258 return (-2); 259 } 260 (void)strlcpy(record, toprec, len); 261 db_p = db_array; 262 rp = record + topreclen + 1; 263 r_end = rp + BFRAG; 264 goto tc_exp; 265 } 266 /* 267 * Allocate first chunk of memory. 268 */ 269 if ((record = malloc(BFRAG)) == NULL) { 270 errno = ENOMEM; 271 return (-2); 272 } 273 r_end = record + BFRAG; 274 foundit = 0; 275 /* 276 * Loop through database array until finding the record. 277 */ 278 279 for (db_p = db_array; *db_p != NULL; db_p++) { 280 eof = 0; 281 282 /* 283 * Open database if not already open. 284 */ 285 286 if (fd >= 0) { 287 (void)lseek(fd, (off_t)0, SEEK_SET); 288 } else { 289 #ifdef USE_DB 290 char pbuf[_POSIX_PATH_MAX]; 291 char *cbuf; 292 size_t clen; 293 int retval; 294 DB *capdbp; 295 296 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p); 297 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0)) 298 != NULL) { 299 free(record); 300 retval = cdbget(capdbp, &record, name); 301 if (retval < 0) { 302 /* no record available */ 303 (void)capdbp->close(capdbp); 304 return (retval); 305 } 306 /* save the data; close frees it */ 307 clen = strlen(record); 308 cbuf = malloc(clen + 1); 309 if (cbuf == NULL) 310 return (-2); 311 memmove(cbuf, record, clen + 1); 312 if (capdbp->close(capdbp) < 0) { 313 free(cbuf); 314 return (-2); 315 } 316 *len = clen; 317 *cap = cbuf; 318 return (retval); 319 } else 320 #endif 321 { 322 fd = open(*db_p, O_RDONLY, 0); 323 if (fd < 0) { 324 /* No error on unfound file. */ 325 continue; 326 } 327 myfd = 1; 328 } 329 } 330 /* 331 * Find the requested capability record ... 332 */ 333 { 334 char buf[BUFSIZ]; 335 char *b_end, *bp, *cp; 336 int c, slash; 337 338 /* 339 * Loop invariants: 340 * There is always room for one more character in record. 341 * R_end always points just past end of record. 342 * Rp always points just past last character in record. 343 * B_end always points just past last character in buf. 344 * Bp always points at next character in buf. 345 * Cp remembers where the last colon was. 346 */ 347 b_end = buf; 348 bp = buf; 349 cp = 0; 350 slash = 0; 351 for (;;) { 352 353 /* 354 * Read in a line implementing (\, newline) 355 * line continuation. 356 */ 357 rp = record; 358 for (;;) { 359 if (bp >= b_end) { 360 int n; 361 362 n = read(fd, buf, sizeof(buf)); 363 if (n <= 0) { 364 if (myfd) 365 (void)close(fd); 366 if (n < 0) { 367 free(record); 368 return (-2); 369 } else { 370 fd = -1; 371 eof = 1; 372 break; 373 } 374 } 375 b_end = buf+n; 376 bp = buf; 377 } 378 379 c = *bp++; 380 if (c == '\n') { 381 if (slash) { 382 slash = 0; 383 rp--; 384 continue; 385 } else 386 break; 387 } 388 if (slash) { 389 slash = 0; 390 cp = 0; 391 } 392 if (c == ':') { 393 /* 394 * If the field was `empty' (i.e. 395 * contained only white space), back up 396 * to the colon (eliminating the 397 * field). 398 */ 399 if (cp) 400 rp = cp; 401 else 402 cp = rp; 403 } else if (c == '\\') { 404 slash = 1; 405 } else if (c != ' ' && c != '\t') { 406 /* 407 * Forget where the colon was, as this 408 * is not an empty field. 409 */ 410 cp = 0; 411 } 412 *rp++ = c; 413 414 /* 415 * Enforce loop invariant: if no room 416 * left in record buffer, try to get 417 * some more. 418 */ 419 if (rp >= r_end) { 420 u_int pos; 421 size_t newsize; 422 423 pos = rp - record; 424 newsize = r_end - record + BFRAG; 425 record = realloc(record, newsize); 426 if (record == NULL) { 427 errno = ENOMEM; 428 if (myfd) 429 (void)close(fd); 430 return (-2); 431 } 432 r_end = record + newsize; 433 rp = record + pos; 434 } 435 } 436 /* Eliminate any white space after the last colon. */ 437 if (cp) 438 rp = cp + 1; 439 /* Loop invariant lets us do this. */ 440 *rp++ = '\0'; 441 442 /* 443 * If encountered eof check next file. 444 */ 445 if (eof) 446 break; 447 448 /* 449 * Toss blank lines and comments. 450 */ 451 if (*record == '\0' || *record == '#') 452 continue; 453 454 /* 455 * See if this is the record we want ... 456 */ 457 if (cgetmatch(record, name) == 0) { 458 if (nfield == NULL || !nfcmp(nfield, record)) { 459 foundit = 1; 460 break; /* found it! */ 461 } 462 } 463 } 464 } 465 if (foundit) 466 break; 467 } 468 469 if (!foundit) 470 return (-1); 471 472 /* 473 * Got the capability record, but now we have to expand all tc=name 474 * references in it ... 475 */ 476 tc_exp: { 477 char *newicap, *s; 478 size_t ilen, newilen; 479 int diff, iret, tclen; 480 char *icap, *scan, *tc, *tcstart, *tcend; 481 482 /* 483 * Loop invariants: 484 * There is room for one more character in record. 485 * R_end points just past end of record. 486 * Rp points just past last character in record. 487 * Scan points at remainder of record that needs to be 488 * scanned for tc=name constructs. 489 */ 490 scan = record; 491 tc_not_resolved = 0; 492 for (;;) { 493 if ((tc = cgetcap(scan, "tc", '=')) == NULL) 494 break; 495 496 /* 497 * Find end of tc=name and stomp on the trailing `:' 498 * (if present) so we can use it to call ourselves. 499 */ 500 s = tc; 501 for (;;) 502 if (*s == '\0') 503 break; 504 else 505 if (*s++ == ':') { 506 *(s - 1) = '\0'; 507 break; 508 } 509 tcstart = tc - 3; 510 tclen = s - tcstart; 511 tcend = s; 512 513 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1, 514 NULL); 515 newicap = icap; /* Put into a register. */ 516 newilen = ilen; 517 if (iret != 0) { 518 /* an error */ 519 if (iret < -1) { 520 if (myfd) 521 (void)close(fd); 522 free(record); 523 return (iret); 524 } 525 if (iret == 1) 526 tc_not_resolved = 1; 527 /* couldn't resolve tc */ 528 if (iret == -1) { 529 *(s - 1) = ':'; 530 scan = s - 1; 531 tc_not_resolved = 1; 532 continue; 533 534 } 535 } 536 /* not interested in name field of tc'ed record */ 537 s = newicap; 538 for (;;) 539 if (*s == '\0') 540 break; 541 else 542 if (*s++ == ':') 543 break; 544 newilen -= s - newicap; 545 newicap = s; 546 547 /* make sure interpolated record is `:'-terminated */ 548 s += newilen; 549 if (*(s-1) != ':') { 550 *s = ':'; /* overwrite NUL with : */ 551 newilen++; 552 } 553 554 /* 555 * Make sure there's enough room to insert the 556 * new record. 557 */ 558 diff = newilen - tclen; 559 if (diff >= r_end - rp) { 560 u_int pos, tcpos, tcposend; 561 size_t newsize; 562 563 pos = rp - record; 564 newsize = r_end - record + diff + BFRAG; 565 tcpos = tcstart - record; 566 tcposend = tcend - record; 567 record = realloc(record, newsize); 568 if (record == NULL) { 569 errno = ENOMEM; 570 if (myfd) 571 (void)close(fd); 572 free(icap); 573 return (-2); 574 } 575 r_end = record + newsize; 576 rp = record + pos; 577 tcstart = record + tcpos; 578 tcend = record + tcposend; 579 } 580 581 /* 582 * Insert tc'ed record into our record. 583 */ 584 s = tcstart + newilen; 585 memmove(s, tcend, (size_t)(rp - tcend)); 586 memmove(tcstart, newicap, newilen); 587 rp += diff; 588 free(icap); 589 590 /* 591 * Start scan on `:' so next cgetcap works properly 592 * (cgetcap always skips first field). 593 */ 594 scan = s-1; 595 } 596 597 } 598 /* 599 * Close file (if we opened it), give back any extra memory, and 600 * return capability, length and success. 601 */ 602 if (myfd) 603 (void)close(fd); 604 *len = rp - record - 1; /* don't count NUL */ 605 if (r_end > rp) 606 if ((record = 607 realloc(record, (size_t)(rp - record))) == NULL) { 608 errno = ENOMEM; 609 return (-2); 610 } 611 612 *cap = record; 613 if (tc_not_resolved) 614 return (1); 615 return (0); 616 } 617 618 #ifdef USE_DB 619 static int 620 cdbget(DB *capdbp, char **bp, const char *name) 621 { 622 DBT key; 623 DBT data; 624 625 /* LINTED key is not modified */ 626 key.data = (char *)name; 627 key.size = strlen(name); 628 629 for (;;) { 630 /* Get the reference. */ 631 switch(capdbp->get(capdbp, &key, &data, 0)) { 632 case -1: 633 return (-2); 634 case 1: 635 return (-1); 636 } 637 638 /* If not an index to another record, leave. */ 639 if (((char *)data.data)[0] != SHADOW) 640 break; 641 642 key.data = (char *)data.data + 1; 643 key.size = data.size - 1; 644 } 645 646 *bp = (char *)data.data + 1; 647 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 648 } 649 #endif /* USE_DB */ 650 651 /* 652 * Cgetmatch will return 0 if name is one of the names of the capability 653 * record buf, -1 if not. 654 */ 655 int 656 cgetmatch(const char *buf, const char *name) 657 { 658 const char *np, *bp; 659 660 /* 661 * Start search at beginning of record. 662 */ 663 bp = buf; 664 for (;;) { 665 /* 666 * Try to match a record name. 667 */ 668 np = name; 669 for (;;) 670 if (*np == '\0') { 671 if (*bp == '|' || *bp == ':' || *bp == '\0') 672 return (0); 673 else 674 break; 675 } else 676 if (*bp++ != *np++) 677 break; 678 679 /* 680 * Match failed, skip to next name in record. 681 */ 682 bp--; /* a '|' or ':' may have stopped the match */ 683 for (;;) 684 if (*bp == '\0' || *bp == ':') 685 return (-1); /* match failed totally */ 686 else 687 if (*bp++ == '|') 688 break; /* found next name */ 689 } 690 } 691 692 #if 0 693 int 694 cgetfirst(char **buf, char **db_array) 695 { 696 (void)cgetclose(); 697 return (cgetnext(buf, db_array)); 698 } 699 #endif 700 701 static FILE *pfp; 702 static int slash; 703 static char **dbp; 704 705 int ROKEN_LIB_FUNCTION 706 cgetclose(void) 707 { 708 if (pfp != NULL) { 709 (void)fclose(pfp); 710 pfp = NULL; 711 } 712 dbp = NULL; 713 gottoprec = 0; 714 slash = 0; 715 return(0); 716 } 717 718 #if 0 719 /* 720 * Cgetnext() gets either the first or next entry in the logical database 721 * specified by db_array. It returns 0 upon completion of the database, 1 722 * upon returning an entry with more remaining, and -1 if an error occurs. 723 */ 724 int 725 cgetnext(char **bp, char **db_array) 726 { 727 size_t len; 728 int status, done; 729 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE]; 730 size_t dummy; 731 732 if (dbp == NULL) 733 dbp = db_array; 734 735 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) { 736 (void)cgetclose(); 737 return (-1); 738 } 739 for(;;) { 740 if (toprec && !gottoprec) { 741 gottoprec = 1; 742 line = toprec; 743 } else { 744 line = fgetln(pfp, &len); 745 if (line == NULL && pfp) { 746 if (ferror(pfp)) { 747 (void)cgetclose(); 748 return (-1); 749 } else { 750 (void)fclose(pfp); 751 pfp = NULL; 752 if (*++dbp == NULL) { 753 (void)cgetclose(); 754 return (0); 755 } else if ((pfp = 756 fopen(*dbp, "r")) == NULL) { 757 (void)cgetclose(); 758 return (-1); 759 } else 760 continue; 761 } 762 } else 763 line[len - 1] = '\0'; 764 if (len == 1) { 765 slash = 0; 766 continue; 767 } 768 if (isspace((unsigned char)*line) || 769 *line == ':' || *line == '#' || slash) { 770 if (line[len - 2] == '\\') 771 slash = 1; 772 else 773 slash = 0; 774 continue; 775 } 776 if (line[len - 2] == '\\') 777 slash = 1; 778 else 779 slash = 0; 780 } 781 782 783 /* 784 * Line points to a name line. 785 */ 786 done = 0; 787 np = nbuf; 788 for (;;) { 789 for (cp = line; *cp != '\0'; cp++) { 790 if (*cp == ':') { 791 *np++ = ':'; 792 done = 1; 793 break; 794 } 795 if (*cp == '\\') 796 break; 797 *np++ = *cp; 798 } 799 if (done) { 800 *np = '\0'; 801 break; 802 } else { /* name field extends beyond the line */ 803 line = fgetln(pfp, &len); 804 if (line == NULL && pfp) { 805 if (ferror(pfp)) { 806 (void)cgetclose(); 807 return (-1); 808 } 809 (void)fclose(pfp); 810 pfp = NULL; 811 *np = '\0'; 812 break; 813 } else 814 line[len - 1] = '\0'; 815 } 816 } 817 rp = buf; 818 for(cp = nbuf; *cp != '\0'; cp++) 819 if (*cp == '|' || *cp == ':') 820 break; 821 else 822 *rp++ = *cp; 823 824 *rp = '\0'; 825 /* 826 * XXX 827 * Last argument of getent here should be nbuf if we want true 828 * sequential access in the case of duplicates. 829 * With NULL, getent will return the first entry found 830 * rather than the duplicate entry record. This is a 831 * matter of semantics that should be resolved. 832 */ 833 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL); 834 if (status == -2 || status == -3) 835 (void)cgetclose(); 836 837 return (status + 1); 838 } 839 /* NOTREACHED */ 840 } 841 #endif 842 843 /* 844 * Cgetstr retrieves the value of the string capability cap from the 845 * capability record pointed to by buf. A pointer to a decoded, NUL 846 * terminated, malloc'd copy of the string is returned in the char * 847 * pointed to by str. The length of the string not including the trailing 848 * NUL is returned on success, -1 if the requested string capability 849 * couldn't be found, -2 if a system error was encountered (storage 850 * allocation failure). 851 */ 852 int ROKEN_LIB_FUNCTION 853 cgetstr(char *buf, const char *cap, char **str) 854 { 855 u_int m_room; 856 const char *bp; 857 char *mp; 858 int len; 859 char *mem; 860 861 /* 862 * Find string capability cap 863 */ 864 bp = cgetcap(buf, cap, '='); 865 if (bp == NULL) 866 return (-1); 867 868 /* 869 * Conversion / storage allocation loop ... Allocate memory in 870 * chunks SFRAG in size. 871 */ 872 if ((mem = malloc(SFRAG)) == NULL) { 873 errno = ENOMEM; 874 return (-2); /* couldn't even allocate the first fragment */ 875 } 876 m_room = SFRAG; 877 mp = mem; 878 879 while (*bp != ':' && *bp != '\0') { 880 /* 881 * Loop invariants: 882 * There is always room for one more character in mem. 883 * Mp always points just past last character in mem. 884 * Bp always points at next character in buf. 885 */ 886 if (*bp == '^') { 887 bp++; 888 if (*bp == ':' || *bp == '\0') 889 break; /* drop unfinished escape */ 890 *mp++ = *bp++ & 037; 891 } else if (*bp == '\\') { 892 bp++; 893 if (*bp == ':' || *bp == '\0') 894 break; /* drop unfinished escape */ 895 if ('0' <= *bp && *bp <= '7') { 896 int n, i; 897 898 n = 0; 899 i = 3; /* maximum of three octal digits */ 900 do { 901 n = n * 8 + (*bp++ - '0'); 902 } while (--i && '0' <= *bp && *bp <= '7'); 903 *mp++ = n; 904 } 905 else switch (*bp++) { 906 case 'b': case 'B': 907 *mp++ = '\b'; 908 break; 909 case 't': case 'T': 910 *mp++ = '\t'; 911 break; 912 case 'n': case 'N': 913 *mp++ = '\n'; 914 break; 915 case 'f': case 'F': 916 *mp++ = '\f'; 917 break; 918 case 'r': case 'R': 919 *mp++ = '\r'; 920 break; 921 case 'e': case 'E': 922 *mp++ = ESC; 923 break; 924 case 'c': case 'C': 925 *mp++ = ':'; 926 break; 927 default: 928 /* 929 * Catches '\', '^', and 930 * everything else. 931 */ 932 *mp++ = *(bp-1); 933 break; 934 } 935 } else 936 *mp++ = *bp++; 937 m_room--; 938 939 /* 940 * Enforce loop invariant: if no room left in current 941 * buffer, try to get some more. 942 */ 943 if (m_room == 0) { 944 size_t size = mp - mem; 945 946 if ((mem = realloc(mem, size + SFRAG)) == NULL) 947 return (-2); 948 m_room = SFRAG; 949 mp = mem + size; 950 } 951 } 952 *mp++ = '\0'; /* loop invariant let's us do this */ 953 m_room--; 954 len = mp - mem - 1; 955 956 /* 957 * Give back any extra memory and return value and success. 958 */ 959 if (m_room != 0) 960 if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL) 961 return (-2); 962 *str = mem; 963 return (len); 964 } 965 966 /* 967 * Cgetustr retrieves the value of the string capability cap from the 968 * capability record pointed to by buf. The difference between cgetustr() 969 * and cgetstr() is that cgetustr does not decode escapes but rather treats 970 * all characters literally. A pointer to a NUL terminated malloc'd 971 * copy of the string is returned in the char pointed to by str. The 972 * length of the string not including the trailing NUL is returned on success, 973 * -1 if the requested string capability couldn't be found, -2 if a system 974 * error was encountered (storage allocation failure). 975 */ 976 int ROKEN_LIB_FUNCTION 977 cgetustr(char *buf, const char *cap, char **str) 978 { 979 u_int m_room; 980 const char *bp; 981 char *mp; 982 int len; 983 char *mem; 984 985 /* 986 * Find string capability cap 987 */ 988 if ((bp = cgetcap(buf, cap, '=')) == NULL) 989 return (-1); 990 991 /* 992 * Conversion / storage allocation loop ... Allocate memory in 993 * chunks SFRAG in size. 994 */ 995 if ((mem = malloc(SFRAG)) == NULL) { 996 errno = ENOMEM; 997 return (-2); /* couldn't even allocate the first fragment */ 998 } 999 m_room = SFRAG; 1000 mp = mem; 1001 1002 while (*bp != ':' && *bp != '\0') { 1003 /* 1004 * Loop invariants: 1005 * There is always room for one more character in mem. 1006 * Mp always points just past last character in mem. 1007 * Bp always points at next character in buf. 1008 */ 1009 *mp++ = *bp++; 1010 m_room--; 1011 1012 /* 1013 * Enforce loop invariant: if no room left in current 1014 * buffer, try to get some more. 1015 */ 1016 if (m_room == 0) { 1017 size_t size = mp - mem; 1018 1019 if ((mem = realloc(mem, size + SFRAG)) == NULL) 1020 return (-2); 1021 m_room = SFRAG; 1022 mp = mem + size; 1023 } 1024 } 1025 *mp++ = '\0'; /* loop invariant let's us do this */ 1026 m_room--; 1027 len = mp - mem - 1; 1028 1029 /* 1030 * Give back any extra memory and return value and success. 1031 */ 1032 if (m_room != 0) 1033 if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL) 1034 return (-2); 1035 *str = mem; 1036 return (len); 1037 } 1038 1039 /* 1040 * Cgetnum retrieves the value of the numeric capability cap from the 1041 * capability record pointed to by buf. The numeric value is returned in 1042 * the long pointed to by num. 0 is returned on success, -1 if the requested 1043 * numeric capability couldn't be found. 1044 */ 1045 int ROKEN_LIB_FUNCTION 1046 cgetnum(char *buf, const char *cap, long *num) 1047 { 1048 long n; 1049 int base, digit; 1050 const char *bp; 1051 1052 /* 1053 * Find numeric capability cap 1054 */ 1055 bp = cgetcap(buf, cap, '#'); 1056 if (bp == NULL) 1057 return (-1); 1058 1059 /* 1060 * Look at value and determine numeric base: 1061 * 0x... or 0X... hexadecimal, 1062 * else 0... octal, 1063 * else decimal. 1064 */ 1065 if (*bp == '0') { 1066 bp++; 1067 if (*bp == 'x' || *bp == 'X') { 1068 bp++; 1069 base = 16; 1070 } else 1071 base = 8; 1072 } else 1073 base = 10; 1074 1075 /* 1076 * Conversion loop ... 1077 */ 1078 n = 0; 1079 for (;;) { 1080 if ('0' <= *bp && *bp <= '9') 1081 digit = *bp - '0'; 1082 else if ('a' <= *bp && *bp <= 'f') 1083 digit = 10 + *bp - 'a'; 1084 else if ('A' <= *bp && *bp <= 'F') 1085 digit = 10 + *bp - 'A'; 1086 else 1087 break; 1088 1089 if (digit >= base) 1090 break; 1091 1092 n = n * base + digit; 1093 bp++; 1094 } 1095 1096 /* 1097 * Return value and success. 1098 */ 1099 *num = n; 1100 return (0); 1101 } 1102 1103 1104 /* 1105 * Compare name field of record. 1106 */ 1107 static int 1108 nfcmp(char *nf, char *rec) 1109 { 1110 char *cp, tmp; 1111 int ret; 1112 1113 for (cp = rec; *cp != ':'; cp++) 1114 ; 1115 1116 tmp = *(cp + 1); 1117 *(cp + 1) = '\0'; 1118 ret = strcmp(nf, rec); 1119 *(cp + 1) = tmp; 1120 1121 return (ret); 1122 } 1123