1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Casey Leedom of Lawrence Livermore National Laboratory. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * $FreeBSD$ 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 static char sccsid[] = "@(#)getcap.c 8.3 (Berkeley) 3/25/94"; 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/types.h> 44 45 #include <ctype.h> 46 #include <db.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <limits.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #define BFRAG 1024 56 #define BSIZE 1024 57 #define ESC ('[' & 037) /* ASCII ESC */ 58 #define MAX_RECURSION 32 /* maximum getent recursion */ 59 #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */ 60 61 #define RECOK (char)0 62 #define TCERR (char)1 63 #define SHADOW (char)2 64 65 static size_t topreclen; /* toprec length */ 66 static char *toprec; /* Additional record specified by cgetset() */ 67 static int gottoprec; /* Flag indicating retrieval of toprecord */ 68 69 static int cdbget __P((DB *, char **, char *)); 70 static int getent __P((char **, u_int *, char **, int, char *, int, char *)); 71 static int nfcmp __P((char *, char *)); 72 73 /* 74 * Cgetset() allows the addition of a user specified buffer to be added 75 * to the database array, in effect "pushing" the buffer on top of the 76 * virtual database. 0 is returned on success, -1 on failure. 77 */ 78 int 79 cgetset(ent) 80 char *ent; 81 { 82 if (ent == NULL) { 83 if (toprec) 84 free(toprec); 85 toprec = NULL; 86 topreclen = 0; 87 return (0); 88 } 89 topreclen = strlen(ent); 90 if ((toprec = malloc (topreclen + 1)) == NULL) { 91 errno = ENOMEM; 92 return (-1); 93 } 94 gottoprec = 0; 95 (void)strcpy(toprec, ent); 96 return (0); 97 } 98 99 /* 100 * Cgetcap searches the capability record buf for the capability cap with 101 * type `type'. A pointer to the value of cap is returned on success, NULL 102 * if the requested capability couldn't be found. 103 * 104 * Specifying a type of ':' means that nothing should follow cap (:cap:). 105 * In this case a pointer to the terminating ':' or NUL will be returned if 106 * cap is found. 107 * 108 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator) 109 * return NULL. 110 */ 111 char * 112 cgetcap(buf, cap, type) 113 char *buf, *cap; 114 int type; 115 { 116 register char *bp, *cp; 117 118 bp = buf; 119 for (;;) { 120 /* 121 * Skip past the current capability field - it's either the 122 * name field if this is the first time through the loop, or 123 * the remainder of a field whose name failed to match cap. 124 */ 125 for (;;) 126 if (*bp == '\0') 127 return (NULL); 128 else 129 if (*bp++ == ':') 130 break; 131 132 /* 133 * Try to match (cap, type) in buf. 134 */ 135 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++) 136 continue; 137 if (*cp != '\0') 138 continue; 139 if (*bp == '@') 140 return (NULL); 141 if (type == ':') { 142 if (*bp != '\0' && *bp != ':') 143 continue; 144 return(bp); 145 } 146 if (*bp != type) 147 continue; 148 bp++; 149 return (*bp == '@' ? NULL : bp); 150 } 151 /* NOTREACHED */ 152 } 153 154 /* 155 * Cgetent extracts the capability record name from the NULL terminated file 156 * array db_array and returns a pointer to a malloc'd copy of it in buf. 157 * Buf must be retained through all subsequent calls to cgetcap, cgetnum, 158 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success, 159 * -1 if the requested record couldn't be found, -2 if a system error was 160 * encountered (couldn't open/read a file, etc.), and -3 if a potential 161 * reference loop is detected. 162 */ 163 int 164 cgetent(buf, db_array, name) 165 char **buf, **db_array, *name; 166 { 167 u_int dummy; 168 169 return (getent(buf, &dummy, db_array, -1, name, 0, NULL)); 170 } 171 172 /* 173 * Getent implements the functions of cgetent. If fd is non-negative, 174 * *db_array has already been opened and fd is the open file descriptor. We 175 * do this to save time and avoid using up file descriptors for tc= 176 * recursions. 177 * 178 * Getent returns the same success/failure codes as cgetent. On success, a 179 * pointer to a malloc'ed capability record with all tc= capabilities fully 180 * expanded and its length (not including trailing ASCII NUL) are left in 181 * *cap and *len. 182 * 183 * Basic algorithm: 184 * + Allocate memory incrementally as needed in chunks of size BFRAG 185 * for capability buffer. 186 * + Recurse for each tc=name and interpolate result. Stop when all 187 * names interpolated, a name can't be found, or depth exceeds 188 * MAX_RECURSION. 189 */ 190 static int 191 getent(cap, len, db_array, fd, name, depth, nfield) 192 char **cap, **db_array, *name, *nfield; 193 u_int *len; 194 int fd, depth; 195 { 196 DB *capdbp; 197 register char *r_end, *rp, **db_p; 198 int myfd, eof, foundit, retval, clen; 199 char *record, *cbuf; 200 int tc_not_resolved; 201 char pbuf[_POSIX_PATH_MAX]; 202 203 /* 204 * Return with ``loop detected'' error if we've recursed more than 205 * MAX_RECURSION times. 206 */ 207 if (depth > MAX_RECURSION) 208 return (-3); 209 210 /* 211 * Check if we have a top record from cgetset(). 212 */ 213 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) { 214 if ((record = malloc (topreclen + BFRAG)) == NULL) { 215 errno = ENOMEM; 216 return (-2); 217 } 218 (void)strcpy(record, toprec); 219 myfd = 0; 220 db_p = db_array; 221 rp = record + topreclen + 1; 222 r_end = rp + BFRAG; 223 goto tc_exp; 224 } 225 /* 226 * Allocate first chunk of memory. 227 */ 228 if ((record = malloc(BFRAG)) == NULL) { 229 errno = ENOMEM; 230 return (-2); 231 } 232 r_end = record + BFRAG; 233 foundit = 0; 234 /* 235 * Loop through database array until finding the record. 236 */ 237 238 for (db_p = db_array; *db_p != NULL; db_p++) { 239 eof = 0; 240 241 /* 242 * Open database if not already open. 243 */ 244 245 if (fd >= 0) { 246 (void)lseek(fd, (off_t)0, SEEK_SET); 247 myfd = 0; 248 } else { 249 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p); 250 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0)) 251 != NULL) { 252 free(record); 253 retval = cdbget(capdbp, &record, name); 254 if (retval < 0) { 255 /* no record available */ 256 (void)capdbp->close(capdbp); 257 return (retval); 258 } 259 /* save the data; close frees it */ 260 clen = strlen(record); 261 cbuf = malloc(clen + 1); 262 memcpy(cbuf, record, clen + 1); 263 if (capdbp->close(capdbp) < 0) { 264 free(cbuf); 265 return (-2); 266 } 267 *len = clen; 268 *cap = cbuf; 269 return (retval); 270 } else { 271 fd = _open(*db_p, O_RDONLY, 0); 272 if (fd < 0) 273 continue; 274 myfd = 1; 275 } 276 } 277 /* 278 * Find the requested capability record ... 279 */ 280 { 281 char buf[BUFSIZ]; 282 register char *b_end, *bp; 283 register int c; 284 285 /* 286 * Loop invariants: 287 * There is always room for one more character in record. 288 * R_end always points just past end of record. 289 * Rp always points just past last character in record. 290 * B_end always points just past last character in buf. 291 * Bp always points at next character in buf. 292 */ 293 b_end = buf; 294 bp = buf; 295 for (;;) { 296 297 /* 298 * Read in a line implementing (\, newline) 299 * line continuation. 300 */ 301 rp = record; 302 for (;;) { 303 if (bp >= b_end) { 304 int n; 305 306 n = _read(fd, buf, sizeof(buf)); 307 if (n <= 0) { 308 if (myfd) 309 (void)_close(fd); 310 if (n < 0) { 311 free(record); 312 return (-2); 313 } else { 314 fd = -1; 315 eof = 1; 316 break; 317 } 318 } 319 b_end = buf+n; 320 bp = buf; 321 } 322 323 c = *bp++; 324 if (c == '\n') { 325 if (rp > record && *(rp-1) == '\\') { 326 rp--; 327 continue; 328 } else 329 break; 330 } 331 *rp++ = c; 332 333 /* 334 * Enforce loop invariant: if no room 335 * left in record buffer, try to get 336 * some more. 337 */ 338 if (rp >= r_end) { 339 u_int pos; 340 size_t newsize; 341 342 pos = rp - record; 343 newsize = r_end - record + BFRAG; 344 record = reallocf(record, newsize); 345 if (record == NULL) { 346 errno = ENOMEM; 347 if (myfd) 348 (void)_close(fd); 349 return (-2); 350 } 351 r_end = record + newsize; 352 rp = record + pos; 353 } 354 } 355 /* loop invariant let's us do this */ 356 *rp++ = '\0'; 357 358 /* 359 * If encountered eof check next file. 360 */ 361 if (eof) 362 break; 363 364 /* 365 * Toss blank lines and comments. 366 */ 367 if (*record == '\0' || *record == '#') 368 continue; 369 370 /* 371 * See if this is the record we want ... 372 */ 373 if (cgetmatch(record, name) == 0) { 374 if (nfield == NULL || !nfcmp(nfield, record)) { 375 foundit = 1; 376 break; /* found it! */ 377 } 378 } 379 } 380 } 381 if (foundit) 382 break; 383 } 384 385 if (!foundit) { 386 free(record); 387 return (-1); 388 } 389 390 /* 391 * Got the capability record, but now we have to expand all tc=name 392 * references in it ... 393 */ 394 tc_exp: { 395 register char *newicap, *s; 396 register int newilen; 397 u_int ilen; 398 int diff, iret, tclen; 399 char *icap, *scan, *tc, *tcstart, *tcend; 400 401 /* 402 * Loop invariants: 403 * There is room for one more character in record. 404 * R_end points just past end of record. 405 * Rp points just past last character in record. 406 * Scan points at remainder of record that needs to be 407 * scanned for tc=name constructs. 408 */ 409 scan = record; 410 tc_not_resolved = 0; 411 for (;;) { 412 if ((tc = cgetcap(scan, "tc", '=')) == NULL) 413 break; 414 415 /* 416 * Find end of tc=name and stomp on the trailing `:' 417 * (if present) so we can use it to call ourselves. 418 */ 419 s = tc; 420 for (;;) 421 if (*s == '\0') 422 break; 423 else 424 if (*s++ == ':') { 425 *(s - 1) = '\0'; 426 break; 427 } 428 tcstart = tc - 3; 429 tclen = s - tcstart; 430 tcend = s; 431 432 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1, 433 NULL); 434 newicap = icap; /* Put into a register. */ 435 newilen = ilen; 436 if (iret != 0) { 437 /* an error */ 438 if (iret < -1) { 439 if (myfd) 440 (void)_close(fd); 441 free(record); 442 return (iret); 443 } 444 if (iret == 1) 445 tc_not_resolved = 1; 446 /* couldn't resolve tc */ 447 if (iret == -1) { 448 *(s - 1) = ':'; 449 scan = s - 1; 450 tc_not_resolved = 1; 451 continue; 452 453 } 454 } 455 /* not interested in name field of tc'ed record */ 456 s = newicap; 457 for (;;) 458 if (*s == '\0') 459 break; 460 else 461 if (*s++ == ':') 462 break; 463 newilen -= s - newicap; 464 newicap = s; 465 466 /* make sure interpolated record is `:'-terminated */ 467 s += newilen; 468 if (*(s-1) != ':') { 469 *s = ':'; /* overwrite NUL with : */ 470 newilen++; 471 } 472 473 /* 474 * Make sure there's enough room to insert the 475 * new record. 476 */ 477 diff = newilen - tclen; 478 if (diff >= r_end - rp) { 479 u_int pos, tcpos, tcposend; 480 size_t newsize; 481 482 pos = rp - record; 483 newsize = r_end - record + diff + BFRAG; 484 tcpos = tcstart - record; 485 tcposend = tcend - record; 486 record = reallocf(record, newsize); 487 if (record == NULL) { 488 errno = ENOMEM; 489 if (myfd) 490 (void)_close(fd); 491 free(icap); 492 return (-2); 493 } 494 r_end = record + newsize; 495 rp = record + pos; 496 tcstart = record + tcpos; 497 tcend = record + tcposend; 498 } 499 500 /* 501 * Insert tc'ed record into our record. 502 */ 503 s = tcstart + newilen; 504 bcopy(tcend, s, rp - tcend); 505 bcopy(newicap, tcstart, newilen); 506 rp += diff; 507 free(icap); 508 509 /* 510 * Start scan on `:' so next cgetcap works properly 511 * (cgetcap always skips first field). 512 */ 513 scan = s-1; 514 } 515 516 } 517 /* 518 * Close file (if we opened it), give back any extra memory, and 519 * return capability, length and success. 520 */ 521 if (myfd) 522 (void)_close(fd); 523 *len = rp - record - 1; /* don't count NUL */ 524 if (r_end > rp) 525 if ((record = 526 reallocf(record, (size_t)(rp - record))) == NULL) { 527 errno = ENOMEM; 528 return (-2); 529 } 530 531 *cap = record; 532 if (tc_not_resolved) 533 return (1); 534 return (0); 535 } 536 537 static int 538 cdbget(capdbp, bp, name) 539 DB *capdbp; 540 char **bp, *name; 541 { 542 DBT key, data; 543 544 key.data = name; 545 key.size = strlen(name); 546 547 for (;;) { 548 /* Get the reference. */ 549 switch(capdbp->get(capdbp, &key, &data, 0)) { 550 case -1: 551 return (-2); 552 case 1: 553 return (-1); 554 } 555 556 /* If not an index to another record, leave. */ 557 if (((char *)data.data)[0] != SHADOW) 558 break; 559 560 key.data = (char *)data.data + 1; 561 key.size = data.size - 1; 562 } 563 564 *bp = (char *)data.data + 1; 565 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 566 } 567 568 /* 569 * Cgetmatch will return 0 if name is one of the names of the capability 570 * record buf, -1 if not. 571 */ 572 int 573 cgetmatch(buf, name) 574 char *buf, *name; 575 { 576 register char *np, *bp; 577 578 /* 579 * Start search at beginning of record. 580 */ 581 bp = buf; 582 for (;;) { 583 /* 584 * Try to match a record name. 585 */ 586 np = name; 587 for (;;) 588 if (*np == '\0') 589 if (*bp == '|' || *bp == ':' || *bp == '\0') 590 return (0); 591 else 592 break; 593 else 594 if (*bp++ != *np++) 595 break; 596 597 /* 598 * Match failed, skip to next name in record. 599 */ 600 bp--; /* a '|' or ':' may have stopped the match */ 601 for (;;) 602 if (*bp == '\0' || *bp == ':') 603 return (-1); /* match failed totally */ 604 else 605 if (*bp++ == '|') 606 break; /* found next name */ 607 } 608 } 609 610 611 612 613 614 int 615 cgetfirst(buf, db_array) 616 char **buf, **db_array; 617 { 618 (void)cgetclose(); 619 return (cgetnext(buf, db_array)); 620 } 621 622 static FILE *pfp; 623 static int slash; 624 static char **dbp; 625 626 int 627 cgetclose() 628 { 629 if (pfp != NULL) { 630 (void)fclose(pfp); 631 pfp = NULL; 632 } 633 dbp = NULL; 634 gottoprec = 0; 635 slash = 0; 636 return(0); 637 } 638 639 /* 640 * Cgetnext() gets either the first or next entry in the logical database 641 * specified by db_array. It returns 0 upon completion of the database, 1 642 * upon returning an entry with more remaining, and -1 if an error occurs. 643 */ 644 int 645 cgetnext(bp, db_array) 646 register char **bp; 647 char **db_array; 648 { 649 size_t len; 650 int status, i, done; 651 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE]; 652 u_int dummy; 653 654 if (dbp == NULL) 655 dbp = db_array; 656 657 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) { 658 (void)cgetclose(); 659 return (-1); 660 } 661 for(;;) { 662 if (toprec && !gottoprec) { 663 gottoprec = 1; 664 line = toprec; 665 } else { 666 line = fgetln(pfp, &len); 667 if (line == NULL && pfp) { 668 (void)fclose(pfp); 669 if (ferror(pfp)) { 670 (void)cgetclose(); 671 return (-1); 672 } else { 673 if (*++dbp == NULL) { 674 (void)cgetclose(); 675 return (0); 676 } else if ((pfp = 677 fopen(*dbp, "r")) == NULL) { 678 (void)cgetclose(); 679 return (-1); 680 } else 681 continue; 682 } 683 } else 684 line[len - 1] = '\0'; 685 if (len == 1) { 686 slash = 0; 687 continue; 688 } 689 if (isspace((unsigned char)*line) || 690 *line == ':' || *line == '#' || slash) { 691 if (line[len - 2] == '\\') 692 slash = 1; 693 else 694 slash = 0; 695 continue; 696 } 697 if (line[len - 2] == '\\') 698 slash = 1; 699 else 700 slash = 0; 701 } 702 703 704 /* 705 * Line points to a name line. 706 */ 707 i = 0; 708 done = 0; 709 np = nbuf; 710 for (;;) { 711 for (cp = line; *cp != '\0'; cp++) { 712 if (*cp == ':') { 713 *np++ = ':'; 714 done = 1; 715 break; 716 } 717 if (*cp == '\\') 718 break; 719 *np++ = *cp; 720 } 721 if (done) { 722 *np = '\0'; 723 break; 724 } else { /* name field extends beyond the line */ 725 line = fgetln(pfp, &len); 726 if (line == NULL && pfp) { 727 (void)fclose(pfp); 728 if (ferror(pfp)) { 729 (void)cgetclose(); 730 return (-1); 731 } 732 } else 733 line[len - 1] = '\0'; 734 } 735 } 736 rp = buf; 737 for(cp = nbuf; *cp != '\0'; cp++) 738 if (*cp == '|' || *cp == ':') 739 break; 740 else 741 *rp++ = *cp; 742 743 *rp = '\0'; 744 /* 745 * XXX 746 * Last argument of getent here should be nbuf if we want true 747 * sequential access in the case of duplicates. 748 * With NULL, getent will return the first entry found 749 * rather than the duplicate entry record. This is a 750 * matter of semantics that should be resolved. 751 */ 752 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL); 753 if (status == -2 || status == -3) 754 (void)cgetclose(); 755 756 return (status + 1); 757 } 758 /* NOTREACHED */ 759 } 760 761 /* 762 * Cgetstr retrieves the value of the string capability cap from the 763 * capability record pointed to by buf. A pointer to a decoded, NUL 764 * terminated, malloc'd copy of the string is returned in the char * 765 * pointed to by str. The length of the string not including the trailing 766 * NUL is returned on success, -1 if the requested string capability 767 * couldn't be found, -2 if a system error was encountered (storage 768 * allocation failure). 769 */ 770 int 771 cgetstr(buf, cap, str) 772 char *buf, *cap; 773 char **str; 774 { 775 register u_int m_room; 776 register char *bp, *mp; 777 int len; 778 char *mem; 779 780 /* 781 * Find string capability cap 782 */ 783 bp = cgetcap(buf, cap, '='); 784 if (bp == NULL) 785 return (-1); 786 787 /* 788 * Conversion / storage allocation loop ... Allocate memory in 789 * chunks SFRAG in size. 790 */ 791 if ((mem = malloc(SFRAG)) == NULL) { 792 errno = ENOMEM; 793 return (-2); /* couldn't even allocate the first fragment */ 794 } 795 m_room = SFRAG; 796 mp = mem; 797 798 while (*bp != ':' && *bp != '\0') { 799 /* 800 * Loop invariants: 801 * There is always room for one more character in mem. 802 * Mp always points just past last character in mem. 803 * Bp always points at next character in buf. 804 */ 805 if (*bp == '^') { 806 bp++; 807 if (*bp == ':' || *bp == '\0') 808 break; /* drop unfinished escape */ 809 if (*bp == '?') { 810 *mp++ = '\177'; 811 bp++; 812 } else 813 *mp++ = *bp++ & 037; 814 } else if (*bp == '\\') { 815 bp++; 816 if (*bp == ':' || *bp == '\0') 817 break; /* drop unfinished escape */ 818 if ('0' <= *bp && *bp <= '7') { 819 register int n, i; 820 821 n = 0; 822 i = 3; /* maximum of three octal digits */ 823 do { 824 n = n * 8 + (*bp++ - '0'); 825 } while (--i && '0' <= *bp && *bp <= '7'); 826 *mp++ = n; 827 } 828 else switch (*bp++) { 829 case 'b': case 'B': 830 *mp++ = '\b'; 831 break; 832 case 't': case 'T': 833 *mp++ = '\t'; 834 break; 835 case 'n': case 'N': 836 *mp++ = '\n'; 837 break; 838 case 'f': case 'F': 839 *mp++ = '\f'; 840 break; 841 case 'r': case 'R': 842 *mp++ = '\r'; 843 break; 844 case 'e': case 'E': 845 *mp++ = ESC; 846 break; 847 case 'c': case 'C': 848 *mp++ = ':'; 849 break; 850 default: 851 /* 852 * Catches '\', '^', and 853 * everything else. 854 */ 855 *mp++ = *(bp-1); 856 break; 857 } 858 } else 859 *mp++ = *bp++; 860 m_room--; 861 862 /* 863 * Enforce loop invariant: if no room left in current 864 * buffer, try to get some more. 865 */ 866 if (m_room == 0) { 867 size_t size = mp - mem; 868 869 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 870 return (-2); 871 m_room = SFRAG; 872 mp = mem + size; 873 } 874 } 875 *mp++ = '\0'; /* loop invariant let's us do this */ 876 m_room--; 877 len = mp - mem - 1; 878 879 /* 880 * Give back any extra memory and return value and success. 881 */ 882 if (m_room != 0) 883 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 884 return (-2); 885 *str = mem; 886 return (len); 887 } 888 889 /* 890 * Cgetustr retrieves the value of the string capability cap from the 891 * capability record pointed to by buf. The difference between cgetustr() 892 * and cgetstr() is that cgetustr does not decode escapes but rather treats 893 * all characters literally. A pointer to a NUL terminated malloc'd 894 * copy of the string is returned in the char pointed to by str. The 895 * length of the string not including the trailing NUL is returned on success, 896 * -1 if the requested string capability couldn't be found, -2 if a system 897 * error was encountered (storage allocation failure). 898 */ 899 int 900 cgetustr(buf, cap, str) 901 char *buf, *cap, **str; 902 { 903 register u_int m_room; 904 register char *bp, *mp; 905 int len; 906 char *mem; 907 908 /* 909 * Find string capability cap 910 */ 911 if ((bp = cgetcap(buf, cap, '=')) == NULL) 912 return (-1); 913 914 /* 915 * Conversion / storage allocation loop ... Allocate memory in 916 * chunks SFRAG in size. 917 */ 918 if ((mem = malloc(SFRAG)) == NULL) { 919 errno = ENOMEM; 920 return (-2); /* couldn't even allocate the first fragment */ 921 } 922 m_room = SFRAG; 923 mp = mem; 924 925 while (*bp != ':' && *bp != '\0') { 926 /* 927 * Loop invariants: 928 * There is always room for one more character in mem. 929 * Mp always points just past last character in mem. 930 * Bp always points at next character in buf. 931 */ 932 *mp++ = *bp++; 933 m_room--; 934 935 /* 936 * Enforce loop invariant: if no room left in current 937 * buffer, try to get some more. 938 */ 939 if (m_room == 0) { 940 size_t size = mp - mem; 941 942 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 943 return (-2); 944 m_room = SFRAG; 945 mp = mem + size; 946 } 947 } 948 *mp++ = '\0'; /* loop invariant let's us do this */ 949 m_room--; 950 len = mp - mem - 1; 951 952 /* 953 * Give back any extra memory and return value and success. 954 */ 955 if (m_room != 0) 956 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 957 return (-2); 958 *str = mem; 959 return (len); 960 } 961 962 /* 963 * Cgetnum retrieves the value of the numeric capability cap from the 964 * capability record pointed to by buf. The numeric value is returned in 965 * the long pointed to by num. 0 is returned on success, -1 if the requested 966 * numeric capability couldn't be found. 967 */ 968 int 969 cgetnum(buf, cap, num) 970 char *buf, *cap; 971 long *num; 972 { 973 register long n; 974 register int base, digit; 975 register char *bp; 976 977 /* 978 * Find numeric capability cap 979 */ 980 bp = cgetcap(buf, cap, '#'); 981 if (bp == NULL) 982 return (-1); 983 984 /* 985 * Look at value and determine numeric base: 986 * 0x... or 0X... hexadecimal, 987 * else 0... octal, 988 * else decimal. 989 */ 990 if (*bp == '0') { 991 bp++; 992 if (*bp == 'x' || *bp == 'X') { 993 bp++; 994 base = 16; 995 } else 996 base = 8; 997 } else 998 base = 10; 999 1000 /* 1001 * Conversion loop ... 1002 */ 1003 n = 0; 1004 for (;;) { 1005 if ('0' <= *bp && *bp <= '9') 1006 digit = *bp - '0'; 1007 else if ('a' <= *bp && *bp <= 'f') 1008 digit = 10 + *bp - 'a'; 1009 else if ('A' <= *bp && *bp <= 'F') 1010 digit = 10 + *bp - 'A'; 1011 else 1012 break; 1013 1014 if (digit >= base) 1015 break; 1016 1017 n = n * base + digit; 1018 bp++; 1019 } 1020 1021 /* 1022 * Return value and success. 1023 */ 1024 *num = n; 1025 return (0); 1026 } 1027 1028 1029 /* 1030 * Compare name field of record. 1031 */ 1032 static int 1033 nfcmp(nf, rec) 1034 char *nf, *rec; 1035 { 1036 char *cp, tmp; 1037 int ret; 1038 1039 for (cp = rec; *cp != ':'; cp++) 1040 ; 1041 1042 tmp = *(cp + 1); 1043 *(cp + 1) = '\0'; 1044 ret = strcmp(nf, rec); 1045 *(cp + 1) = tmp; 1046 1047 return (ret); 1048 } 1049