1 /*- 2 * Copyright (c) 1992 The Regents of the University of California. 3 * 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 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /*static char *sccsid = "from: @(#)getcap.c 5.15 (Berkeley) 3/19/93";*/ 39 static char *rcsid = "$Id: getcap.c,v 1.8 1994/03/26 02:51:45 cgd Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 44 #include <ctype.h> 45 #include <db.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <limits.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #define BFRAG 1024 55 #define BSIZE 1024 56 #define ESC ('[' & 037) /* ASCII ESC */ 57 #define MAX_RECURSION 32 /* maximum getent recursion */ 58 #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */ 59 60 #define RECOK (char)0 61 #define TCERR (char)1 62 #define SHADOW (char)2 63 64 static size_t topreclen; /* toprec length */ 65 static char *toprec; /* Additional record specified by cgetset() */ 66 static int gottoprec; /* Flag indicating retrieval of toprecord */ 67 68 static int cdbget __P((DB *, char **, char *)); 69 static int getent __P((char **, u_int *, char **, int, char *, int, char *)); 70 static int nfcmp __P((char *, char *)); 71 72 /* 73 * Cgetset() allows the addition of a user specified buffer to be added 74 * to the database array, in effect "pushing" the buffer on top of the 75 * virtual database. 0 is returned on success, -1 on failure. 76 */ 77 int 78 cgetset(ent) 79 char *ent; 80 { 81 if (ent == NULL) { 82 if (toprec) 83 free(toprec); 84 toprec = NULL; 85 topreclen = 0; 86 return (0); 87 } 88 topreclen = strlen(ent); 89 if ((toprec = malloc (topreclen + 1)) == NULL) { 90 errno = ENOMEM; 91 return (-1); 92 } 93 gottoprec = 0; 94 (void)strcpy(toprec, ent); 95 return (0); 96 } 97 98 /* 99 * Cgetcap searches the capability record buf for the capability cap with 100 * type `type'. A pointer to the value of cap is returned on success, NULL 101 * if the requested capability couldn't be found. 102 * 103 * Specifying a type of ':' means that nothing should follow cap (:cap:). 104 * In this case a pointer to the terminating ':' or NUL will be returned if 105 * cap is found. 106 * 107 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator) 108 * return NULL. 109 */ 110 char * 111 cgetcap(buf, cap, type) 112 char *buf, *cap; 113 int type; 114 { 115 register char *bp, *cp; 116 117 bp = buf; 118 for (;;) { 119 /* 120 * Skip past the current capability field - it's either the 121 * name field if this is the first time through the loop, or 122 * the remainder of a field whose name failed to match cap. 123 */ 124 for (;;) 125 if (*bp == '\0') 126 return (NULL); 127 else 128 if (*bp++ == ':') 129 break; 130 131 /* 132 * Try to match (cap, type) in buf. 133 */ 134 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++) 135 continue; 136 if (*cp != '\0') 137 continue; 138 if (*bp == '@') 139 return (NULL); 140 if (type == ':') { 141 if (*bp != '\0' && *bp != ':') 142 continue; 143 return(bp); 144 } 145 if (*bp != type) 146 continue; 147 bp++; 148 return (*bp == '@' ? NULL : bp); 149 } 150 /* NOTREACHED */ 151 } 152 153 /* 154 * Cgetent extracts the capability record name from the NULL terminated file 155 * array db_array and returns a pointer to a malloc'd copy of it in buf. 156 * Buf must be retained through all subsequent calls to cgetcap, cgetnum, 157 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success, 158 * -1 if the requested record couldn't be found, -2 if a system error was 159 * encountered (couldn't open/read a file, etc.), and -3 if a potential 160 * reference loop is detected. 161 */ 162 int 163 cgetent(buf, db_array, name) 164 char **buf, **db_array, *name; 165 { 166 u_int dummy; 167 168 return (getent(buf, &dummy, db_array, -1, name, 0, NULL)); 169 } 170 171 /* 172 * Getent implements the functions of cgetent. If fd is non-negative, 173 * *db_array has already been opened and fd is the open file descriptor. We 174 * do this to save time and avoid using up file descriptors for tc= 175 * recursions. 176 * 177 * Getent returns the same success/failure codes as cgetent. On success, a 178 * pointer to a malloc'ed capability record with all tc= capabilities fully 179 * expanded and its length (not including trailing ASCII NUL) are left in 180 * *cap and *len. 181 * 182 * Basic algorithm: 183 * + Allocate memory incrementally as needed in chunks of size BFRAG 184 * for capability buffer. 185 * + Recurse for each tc=name and interpolate result. Stop when all 186 * names interpolated, a name can't be found, or depth exceeds 187 * MAX_RECURSION. 188 */ 189 static int 190 getent(cap, len, db_array, fd, name, depth, nfield) 191 char **cap, **db_array, *name, *nfield; 192 u_int *len; 193 int fd, depth; 194 { 195 DB *capdbp; 196 DBT key, data; 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, L_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 /* No error on unfound file. */ 274 if (errno == ENOENT) 275 continue; 276 free(record); 277 return (-2); 278 } 279 myfd = 1; 280 } 281 } 282 /* 283 * Find the requested capability record ... 284 */ 285 { 286 char buf[BUFSIZ]; 287 register char *b_end, *bp; 288 register int c; 289 290 /* 291 * Loop invariants: 292 * There is always room for one more character in record. 293 * R_end always points just past end of record. 294 * Rp always points just past last character in record. 295 * B_end always points just past last character in buf. 296 * Bp always points at next character in buf. 297 */ 298 b_end = buf; 299 bp = buf; 300 for (;;) { 301 302 /* 303 * Read in a line implementing (\, newline) 304 * line continuation. 305 */ 306 rp = record; 307 for (;;) { 308 if (bp >= b_end) { 309 int n; 310 311 n = read(fd, buf, sizeof(buf)); 312 if (n <= 0) { 313 if (myfd) 314 (void)close(fd); 315 if (n < 0) { 316 free(record); 317 return (-2); 318 } else { 319 fd = -1; 320 eof = 1; 321 break; 322 } 323 } 324 b_end = buf+n; 325 bp = buf; 326 } 327 328 c = *bp++; 329 if (c == '\n') { 330 if (rp > record && *(rp-1) == '\\') { 331 rp--; 332 continue; 333 } else 334 break; 335 } 336 *rp++ = c; 337 338 /* 339 * Enforce loop invariant: if no room 340 * left in record buffer, try to get 341 * some more. 342 */ 343 if (rp >= r_end) { 344 u_int pos; 345 size_t newsize; 346 347 pos = rp - record; 348 newsize = r_end - record + BFRAG; 349 record = realloc(record, newsize); 350 if (record == NULL) { 351 errno = ENOMEM; 352 if (myfd) 353 (void)close(fd); 354 return (-2); 355 } 356 r_end = record + newsize; 357 rp = record + pos; 358 } 359 } 360 /* loop invariant let's us do this */ 361 *rp++ = '\0'; 362 363 /* 364 * If encountered eof check next file. 365 */ 366 if (eof) 367 break; 368 369 /* 370 * Toss blank lines and comments. 371 */ 372 if (*record == '\0' || *record == '#') 373 continue; 374 375 /* 376 * See if this is the record we want ... 377 */ 378 if (cgetmatch(record, name) == 0) { 379 if (nfield == NULL || !nfcmp(nfield, record)) { 380 foundit = 1; 381 break; /* found it! */ 382 } 383 } 384 } 385 } 386 if (foundit) 387 break; 388 } 389 390 if (!foundit) 391 return (-1); 392 393 /* 394 * Got the capability record, but now we have to expand all tc=name 395 * references in it ... 396 */ 397 tc_exp: { 398 register char *newicap, *s; 399 register int newilen; 400 u_int ilen; 401 int diff, iret, tclen; 402 char *icap, *scan, *tc, *tcstart, *tcend; 403 404 /* 405 * Loop invariants: 406 * There is room for one more character in record. 407 * R_end points just past end of record. 408 * Rp points just past last character in record. 409 * Scan points at remainder of record that needs to be 410 * scanned for tc=name constructs. 411 */ 412 scan = record; 413 tc_not_resolved = 0; 414 for (;;) { 415 if ((tc = cgetcap(scan, "tc", '=')) == NULL) 416 break; 417 418 /* 419 * Find end of tc=name and stomp on the trailing `:' 420 * (if present) so we can use it to call ourselves. 421 */ 422 s = tc; 423 for (;;) 424 if (*s == '\0') 425 break; 426 else 427 if (*s++ == ':') { 428 *(s - 1) = '\0'; 429 break; 430 } 431 tcstart = tc - 3; 432 tclen = s - tcstart; 433 tcend = s; 434 435 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1, 436 NULL); 437 newicap = icap; /* Put into a register. */ 438 newilen = ilen; 439 if (iret != 0) { 440 /* an error */ 441 if (iret < -1) { 442 if (myfd) 443 (void)close(fd); 444 free(record); 445 return (iret); 446 } 447 if (iret == 1) 448 tc_not_resolved = 1; 449 /* couldn't resolve tc */ 450 if (iret == -1) { 451 *(s - 1) = ':'; 452 scan = s - 1; 453 tc_not_resolved = 1; 454 continue; 455 456 } 457 } 458 /* not interested in name field of tc'ed record */ 459 s = newicap; 460 for (;;) 461 if (*s == '\0') 462 break; 463 else 464 if (*s++ == ':') 465 break; 466 newilen -= s - newicap; 467 newicap = s; 468 469 /* make sure interpolated record is `:'-terminated */ 470 s += newilen; 471 if (*(s-1) != ':') { 472 *s = ':'; /* overwrite NUL with : */ 473 newilen++; 474 } 475 476 /* 477 * Make sure there's enough room to insert the 478 * new record. 479 */ 480 diff = newilen - tclen; 481 if (diff >= r_end - rp) { 482 u_int pos, tcpos, tcposend; 483 size_t newsize; 484 485 pos = rp - record; 486 newsize = r_end - record + diff + BFRAG; 487 tcpos = tcstart - record; 488 tcposend = tcend - record; 489 record = realloc(record, newsize); 490 if (record == NULL) { 491 errno = ENOMEM; 492 if (myfd) 493 (void)close(fd); 494 free(icap); 495 return (-2); 496 } 497 r_end = record + newsize; 498 rp = record + pos; 499 tcstart = record + tcpos; 500 tcend = record + tcposend; 501 } 502 503 /* 504 * Insert tc'ed record into our record. 505 */ 506 s = tcstart + newilen; 507 bcopy(tcend, s, rp - tcend); 508 bcopy(newicap, tcstart, newilen); 509 rp += diff; 510 free(icap); 511 512 /* 513 * Start scan on `:' so next cgetcap works properly 514 * (cgetcap always skips first field). 515 */ 516 scan = s-1; 517 } 518 519 } 520 /* 521 * Close file (if we opened it), give back any extra memory, and 522 * return capability, length and success. 523 */ 524 if (myfd) 525 (void)close(fd); 526 *len = rp - record - 1; /* don't count NUL */ 527 if (r_end > rp) 528 if ((record = 529 realloc(record, (size_t)(rp - record))) == NULL) { 530 errno = ENOMEM; 531 return (-2); 532 } 533 534 *cap = record; 535 if (tc_not_resolved) 536 return (1); 537 return (0); 538 } 539 540 static int 541 cdbget(capdbp, bp, name) 542 DB *capdbp; 543 char **bp, *name; 544 { 545 DBT key, data; 546 char *buf; 547 int st; 548 549 key.data = name; 550 key.size = strlen(name); 551 552 for (;;) { 553 /* Get the reference. */ 554 switch(capdbp->get(capdbp, &key, &data, 0)) { 555 case -1: 556 return (-2); 557 case 1: 558 return (-1); 559 } 560 561 /* If not an index to another record, leave. */ 562 if (((char *)data.data)[0] != SHADOW) 563 break; 564 565 key.data = (char *)data.data + 1; 566 key.size = data.size - 1; 567 } 568 569 *bp = (char *)data.data + 1; 570 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 571 } 572 573 /* 574 * Cgetmatch will return 0 if name is one of the names of the capability 575 * record buf, -1 if not. 576 */ 577 int 578 cgetmatch(buf, name) 579 char *buf, *name; 580 { 581 register char *np, *bp; 582 583 /* 584 * Start search at beginning of record. 585 */ 586 bp = buf; 587 for (;;) { 588 /* 589 * Try to match a record name. 590 */ 591 np = name; 592 for (;;) 593 if (*np == '\0') 594 if (*bp == '|' || *bp == ':' || *bp == '\0') 595 return (0); 596 else 597 break; 598 else 599 if (*bp++ != *np++) 600 break; 601 602 /* 603 * Match failed, skip to next name in record. 604 */ 605 bp--; /* a '|' or ':' may have stopped the match */ 606 for (;;) 607 if (*bp == '\0' || *bp == ':') 608 return (-1); /* match failed totally */ 609 else 610 if (*bp++ == '|') 611 break; /* found next name */ 612 } 613 } 614 615 616 617 618 619 int 620 cgetfirst(buf, db_array) 621 char **buf, **db_array; 622 { 623 (void)cgetclose(); 624 return (cgetnext(buf, db_array)); 625 } 626 627 static FILE *pfp; 628 static int slash; 629 static char **dbp; 630 631 int 632 cgetclose() 633 { 634 if (pfp != NULL) { 635 (void)fclose(pfp); 636 pfp = NULL; 637 } 638 dbp = NULL; 639 gottoprec = 0; 640 slash = 0; 641 return(0); 642 } 643 644 /* 645 * Cgetnext() gets either the first or next entry in the logical database 646 * specified by db_array. It returns 0 upon completion of the database, 1 647 * upon returning an entry with more remaining, and -1 if an error occurs. 648 */ 649 int 650 cgetnext(bp, db_array) 651 register char **bp; 652 char **db_array; 653 { 654 size_t len; 655 int status, i, done; 656 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE]; 657 u_int dummy; 658 659 if (dbp == NULL) 660 dbp = db_array; 661 662 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) { 663 (void)cgetclose(); 664 return (-1); 665 } 666 for(;;) { 667 if (toprec && !gottoprec) { 668 gottoprec = 1; 669 line = toprec; 670 } else { 671 line = fgetln(pfp, &len); 672 if (line == NULL && pfp) { 673 (void)fclose(pfp); 674 if (ferror(pfp)) { 675 (void)cgetclose(); 676 return (-1); 677 } else { 678 if (*++dbp == NULL) { 679 (void)cgetclose(); 680 return (0); 681 } else if ((pfp = 682 fopen(*dbp, "r")) == NULL) { 683 (void)cgetclose(); 684 return (-1); 685 } else 686 continue; 687 } 688 } else 689 line[len - 1] = '\0'; 690 if (len == 1) { 691 slash = 0; 692 continue; 693 } 694 if (isspace(*line) || 695 *line == ':' || *line == '#' || slash) { 696 if (line[len - 2] == '\\') 697 slash = 1; 698 else 699 slash = 0; 700 continue; 701 } 702 if (line[len - 2] == '\\') 703 slash = 1; 704 else 705 slash = 0; 706 } 707 708 709 /* 710 * Line points to a name line. 711 */ 712 i = 0; 713 done = 0; 714 np = nbuf; 715 for (;;) { 716 for (cp = line; *cp != '\0'; cp++) { 717 if (*cp == ':') { 718 *np++ = ':'; 719 done = 1; 720 break; 721 } 722 if (*cp == '\\') 723 break; 724 *np++ = *cp; 725 } 726 if (done) { 727 *np = '\0'; 728 break; 729 } else { /* name field extends beyond the line */ 730 line = fgetln(pfp, &len); 731 if (line == NULL && pfp) { 732 (void)fclose(pfp); 733 if (ferror(pfp)) { 734 (void)cgetclose(); 735 return (-1); 736 } 737 } else 738 line[len - 1] = '\0'; 739 } 740 } 741 rp = buf; 742 for(cp = nbuf; *cp != NULL; cp++) 743 if (*cp == '|' || *cp == ':') 744 break; 745 else 746 *rp++ = *cp; 747 748 *rp = '\0'; 749 /* 750 * XXX 751 * Last argument of getent here should be nbuf if we want true 752 * sequential access in the case of duplicates. 753 * With NULL, getent will return the first entry found 754 * rather than the duplicate entry record. This is a 755 * matter of semantics that should be resolved. 756 */ 757 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL); 758 if (status == -2 || status == -3) 759 (void)cgetclose(); 760 761 return (status + 1); 762 } 763 /* NOTREACHED */ 764 } 765 766 /* 767 * Cgetstr retrieves the value of the string capability cap from the 768 * capability record pointed to by buf. A pointer to a decoded, NUL 769 * terminated, malloc'd copy of the string is returned in the char * 770 * pointed to by str. The length of the string not including the trailing 771 * NUL is returned on success, -1 if the requested string capability 772 * couldn't be found, -2 if a system error was encountered (storage 773 * allocation failure). 774 */ 775 int 776 cgetstr(buf, cap, str) 777 char *buf, *cap; 778 char **str; 779 { 780 register u_int m_room; 781 register char *bp, *mp; 782 int len; 783 char *mem; 784 785 /* 786 * Find string capability cap 787 */ 788 bp = cgetcap(buf, cap, '='); 789 if (bp == NULL) 790 return (-1); 791 792 /* 793 * Conversion / storage allocation loop ... Allocate memory in 794 * chunks SFRAG in size. 795 */ 796 if ((mem = malloc(SFRAG)) == NULL) { 797 errno = ENOMEM; 798 return (-2); /* couldn't even allocate the first fragment */ 799 } 800 m_room = SFRAG; 801 mp = mem; 802 803 while (*bp != ':' && *bp != '\0') { 804 /* 805 * Loop invariants: 806 * There is always room for one more character in mem. 807 * Mp always points just past last character in mem. 808 * Bp always points at next character in buf. 809 */ 810 if (*bp == '^') { 811 bp++; 812 if (*bp == ':' || *bp == '\0') 813 break; /* drop unfinished escape */ 814 *mp++ = *bp++ & 037; 815 } else if (*bp == '\\') { 816 bp++; 817 if (*bp == ':' || *bp == '\0') 818 break; /* drop unfinished escape */ 819 if ('0' <= *bp && *bp <= '7') { 820 register int n, i; 821 822 n = 0; 823 i = 3; /* maximum of three octal digits */ 824 do { 825 n = n * 8 + (*bp++ - '0'); 826 } while (--i && '0' <= *bp && *bp <= '7'); 827 *mp++ = n; 828 } 829 else switch (*bp++) { 830 case 'b': case 'B': 831 *mp++ = '\b'; 832 break; 833 case 't': case 'T': 834 *mp++ = '\t'; 835 break; 836 case 'n': case 'N': 837 *mp++ = '\n'; 838 break; 839 case 'f': case 'F': 840 *mp++ = '\f'; 841 break; 842 case 'r': case 'R': 843 *mp++ = '\r'; 844 break; 845 case 'e': case 'E': 846 *mp++ = ESC; 847 break; 848 case 'c': case 'C': 849 *mp++ = ':'; 850 break; 851 default: 852 /* 853 * Catches '\', '^', and 854 * everything else. 855 */ 856 *mp++ = *(bp-1); 857 break; 858 } 859 } else 860 *mp++ = *bp++; 861 m_room--; 862 863 /* 864 * Enforce loop invariant: if no room left in current 865 * buffer, try to get some more. 866 */ 867 if (m_room == 0) { 868 size_t size = mp - mem; 869 870 if ((mem = realloc(mem, size + SFRAG)) == NULL) 871 return (-2); 872 m_room = SFRAG; 873 mp = mem + size; 874 } 875 } 876 *mp++ = '\0'; /* loop invariant let's us do this */ 877 m_room--; 878 len = mp - mem - 1; 879 880 /* 881 * Give back any extra memory and return value and success. 882 */ 883 if (m_room != 0) 884 if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL) 885 return (-2); 886 *str = mem; 887 return (len); 888 } 889 890 /* 891 * Cgetustr retrieves the value of the string capability cap from the 892 * capability record pointed to by buf. The difference between cgetustr() 893 * and cgetstr() is that cgetustr does not decode escapes but rather treats 894 * all characters literally. A pointer to a NUL terminated malloc'd 895 * copy of the string is returned in the char pointed to by str. The 896 * length of the string not including the trailing NUL is returned on success, 897 * -1 if the requested string capability couldn't be found, -2 if a system 898 * error was encountered (storage allocation failure). 899 */ 900 int 901 cgetustr(buf, cap, str) 902 char *buf, *cap, **str; 903 { 904 register u_int m_room; 905 register char *bp, *mp; 906 int len; 907 char *mem; 908 909 /* 910 * Find string capability cap 911 */ 912 if ((bp = cgetcap(buf, cap, '=')) == NULL) 913 return (-1); 914 915 /* 916 * Conversion / storage allocation loop ... Allocate memory in 917 * chunks SFRAG in size. 918 */ 919 if ((mem = malloc(SFRAG)) == NULL) { 920 errno = ENOMEM; 921 return (-2); /* couldn't even allocate the first fragment */ 922 } 923 m_room = SFRAG; 924 mp = mem; 925 926 while (*bp != ':' && *bp != '\0') { 927 /* 928 * Loop invariants: 929 * There is always room for one more character in mem. 930 * Mp always points just past last character in mem. 931 * Bp always points at next character in buf. 932 */ 933 *mp++ = *bp++; 934 m_room--; 935 936 /* 937 * Enforce loop invariant: if no room left in current 938 * buffer, try to get some more. 939 */ 940 if (m_room == 0) { 941 size_t size = mp - mem; 942 943 if ((mem = realloc(mem, size + SFRAG)) == NULL) 944 return (-2); 945 m_room = SFRAG; 946 mp = mem + size; 947 } 948 } 949 *mp++ = '\0'; /* loop invariant let's us do this */ 950 m_room--; 951 len = mp - mem - 1; 952 953 /* 954 * Give back any extra memory and return value and success. 955 */ 956 if (m_room != 0) 957 if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL) 958 return (-2); 959 *str = mem; 960 return (len); 961 } 962 963 /* 964 * Cgetnum retrieves the value of the numeric capability cap from the 965 * capability record pointed to by buf. The numeric value is returned in 966 * the long pointed to by num. 0 is returned on success, -1 if the requested 967 * numeric capability couldn't be found. 968 */ 969 int 970 cgetnum(buf, cap, num) 971 char *buf, *cap; 972 long *num; 973 { 974 register long n; 975 register int base, digit; 976 register char *bp; 977 978 /* 979 * Find numeric capability cap 980 */ 981 bp = cgetcap(buf, cap, '#'); 982 if (bp == NULL) 983 return (-1); 984 985 /* 986 * Look at value and determine numeric base: 987 * 0x... or 0X... hexadecimal, 988 * else 0... octal, 989 * else decimal. 990 */ 991 if (*bp == '0') { 992 bp++; 993 if (*bp == 'x' || *bp == 'X') { 994 bp++; 995 base = 16; 996 } else 997 base = 8; 998 } else 999 base = 10; 1000 1001 /* 1002 * Conversion loop ... 1003 */ 1004 n = 0; 1005 for (;;) { 1006 if ('0' <= *bp && *bp <= '9') 1007 digit = *bp - '0'; 1008 else if ('a' <= *bp && *bp <= 'f') 1009 digit = 10 + *bp - 'a'; 1010 else if ('A' <= *bp && *bp <= 'F') 1011 digit = 10 + *bp - 'A'; 1012 else 1013 break; 1014 1015 if (digit >= base) 1016 break; 1017 1018 n = n * base + digit; 1019 bp++; 1020 } 1021 1022 /* 1023 * Return value and success. 1024 */ 1025 *num = n; 1026 return (0); 1027 } 1028 1029 1030 /* 1031 * Compare name field of record. 1032 */ 1033 static int 1034 nfcmp(nf, rec) 1035 char *nf, *rec; 1036 { 1037 char *cp, tmp; 1038 int ret; 1039 1040 for (cp = rec; *cp != ':'; cp++) 1041 ; 1042 1043 tmp = *(cp + 1); 1044 *(cp + 1) = '\0'; 1045 ret = strcmp(nf, rec); 1046 *(cp + 1) = tmp; 1047 1048 return (ret); 1049 } 1050