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: src/lib/libc/gen/getcap.c,v 1.11.2.2 2001/01/15 06:48:09 gad Exp $ 37 * $DragonFly: src/lib/libc/gen/getcap.c,v 1.3 2003/11/12 20:21:23 eirikn Exp $ 38 * 39 * @(#)getcap.c 8.3 (Berkeley) 3/25/94 40 */ 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 (DB *, char **, char *); 69 static int getent (char **, u_int *, char **, int, char *, int, char *); 70 static int nfcmp (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 register char *r_end, *rp, **db_p; 197 int myfd, eof, foundit, retval, clen; 198 char *record, *cbuf; 199 int tc_not_resolved; 200 char pbuf[_POSIX_PATH_MAX]; 201 202 /* 203 * Return with ``loop detected'' error if we've recursed more than 204 * MAX_RECURSION times. 205 */ 206 if (depth > MAX_RECURSION) 207 return (-3); 208 209 /* 210 * Check if we have a top record from cgetset(). 211 */ 212 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) { 213 if ((record = malloc (topreclen + BFRAG)) == NULL) { 214 errno = ENOMEM; 215 return (-2); 216 } 217 (void)strcpy(record, toprec); 218 myfd = 0; 219 db_p = db_array; 220 rp = record + topreclen + 1; 221 r_end = rp + BFRAG; 222 goto tc_exp; 223 } 224 /* 225 * Allocate first chunk of memory. 226 */ 227 if ((record = malloc(BFRAG)) == NULL) { 228 errno = ENOMEM; 229 return (-2); 230 } 231 r_end = record + BFRAG; 232 foundit = 0; 233 /* 234 * Loop through database array until finding the record. 235 */ 236 237 for (db_p = db_array; *db_p != NULL; db_p++) { 238 eof = 0; 239 240 /* 241 * Open database if not already open. 242 */ 243 244 if (fd >= 0) { 245 (void)lseek(fd, (off_t)0, SEEK_SET); 246 myfd = 0; 247 } else { 248 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p); 249 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0)) 250 != NULL) { 251 free(record); 252 retval = cdbget(capdbp, &record, name); 253 if (retval < 0) { 254 /* no record available */ 255 (void)capdbp->close(capdbp); 256 return (retval); 257 } 258 /* save the data; close frees it */ 259 clen = strlen(record); 260 cbuf = malloc(clen + 1); 261 memcpy(cbuf, record, clen + 1); 262 if (capdbp->close(capdbp) < 0) { 263 free(cbuf); 264 return (-2); 265 } 266 *len = clen; 267 *cap = cbuf; 268 return (retval); 269 } else { 270 fd = _open(*db_p, O_RDONLY, 0); 271 if (fd < 0) 272 continue; 273 myfd = 1; 274 } 275 } 276 /* 277 * Find the requested capability record ... 278 */ 279 { 280 char buf[BUFSIZ]; 281 register char *b_end, *bp; 282 register int c; 283 284 /* 285 * Loop invariants: 286 * There is always room for one more character in record. 287 * R_end always points just past end of record. 288 * Rp always points just past last character in record. 289 * B_end always points just past last character in buf. 290 * Bp always points at next character in buf. 291 */ 292 b_end = buf; 293 bp = buf; 294 for (;;) { 295 296 /* 297 * Read in a line implementing (\, newline) 298 * line continuation. 299 */ 300 rp = record; 301 for (;;) { 302 if (bp >= b_end) { 303 int n; 304 305 n = _read(fd, buf, sizeof(buf)); 306 if (n <= 0) { 307 if (myfd) 308 (void)_close(fd); 309 if (n < 0) { 310 free(record); 311 return (-2); 312 } else { 313 fd = -1; 314 eof = 1; 315 break; 316 } 317 } 318 b_end = buf+n; 319 bp = buf; 320 } 321 322 c = *bp++; 323 if (c == '\n') { 324 if (rp > record && *(rp-1) == '\\') { 325 rp--; 326 continue; 327 } else 328 break; 329 } 330 *rp++ = c; 331 332 /* 333 * Enforce loop invariant: if no room 334 * left in record buffer, try to get 335 * some more. 336 */ 337 if (rp >= r_end) { 338 u_int pos; 339 size_t newsize; 340 341 pos = rp - record; 342 newsize = r_end - record + BFRAG; 343 record = reallocf(record, newsize); 344 if (record == NULL) { 345 errno = ENOMEM; 346 if (myfd) 347 (void)_close(fd); 348 return (-2); 349 } 350 r_end = record + newsize; 351 rp = record + pos; 352 } 353 } 354 /* loop invariant let's us do this */ 355 *rp++ = '\0'; 356 357 /* 358 * If encountered eof check next file. 359 */ 360 if (eof) 361 break; 362 363 /* 364 * Toss blank lines and comments. 365 */ 366 if (*record == '\0' || *record == '#') 367 continue; 368 369 /* 370 * See if this is the record we want ... 371 */ 372 if (cgetmatch(record, name) == 0) { 373 if (nfield == NULL || !nfcmp(nfield, record)) { 374 foundit = 1; 375 break; /* found it! */ 376 } 377 } 378 } 379 } 380 if (foundit) 381 break; 382 } 383 384 if (!foundit) { 385 free(record); 386 return (-1); 387 } 388 389 /* 390 * Got the capability record, but now we have to expand all tc=name 391 * references in it ... 392 */ 393 tc_exp: { 394 register char *newicap, *s; 395 register int newilen; 396 u_int ilen; 397 int diff, iret, tclen; 398 char *icap, *scan, *tc, *tcstart, *tcend; 399 400 /* 401 * Loop invariants: 402 * There is room for one more character in record. 403 * R_end points just past end of record. 404 * Rp points just past last character in record. 405 * Scan points at remainder of record that needs to be 406 * scanned for tc=name constructs. 407 */ 408 scan = record; 409 tc_not_resolved = 0; 410 for (;;) { 411 if ((tc = cgetcap(scan, "tc", '=')) == NULL) 412 break; 413 414 /* 415 * Find end of tc=name and stomp on the trailing `:' 416 * (if present) so we can use it to call ourselves. 417 */ 418 s = tc; 419 for (;;) 420 if (*s == '\0') 421 break; 422 else 423 if (*s++ == ':') { 424 *(s - 1) = '\0'; 425 break; 426 } 427 tcstart = tc - 3; 428 tclen = s - tcstart; 429 tcend = s; 430 431 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1, 432 NULL); 433 newicap = icap; /* Put into a register. */ 434 newilen = ilen; 435 if (iret != 0) { 436 /* an error */ 437 if (iret < -1) { 438 if (myfd) 439 (void)_close(fd); 440 free(record); 441 return (iret); 442 } 443 if (iret == 1) 444 tc_not_resolved = 1; 445 /* couldn't resolve tc */ 446 if (iret == -1) { 447 *(s - 1) = ':'; 448 scan = s - 1; 449 tc_not_resolved = 1; 450 continue; 451 452 } 453 } 454 /* not interested in name field of tc'ed record */ 455 s = newicap; 456 for (;;) 457 if (*s == '\0') 458 break; 459 else 460 if (*s++ == ':') 461 break; 462 newilen -= s - newicap; 463 newicap = s; 464 465 /* make sure interpolated record is `:'-terminated */ 466 s += newilen; 467 if (*(s-1) != ':') { 468 *s = ':'; /* overwrite NUL with : */ 469 newilen++; 470 } 471 472 /* 473 * Make sure there's enough room to insert the 474 * new record. 475 */ 476 diff = newilen - tclen; 477 if (diff >= r_end - rp) { 478 u_int pos, tcpos, tcposend; 479 size_t newsize; 480 481 pos = rp - record; 482 newsize = r_end - record + diff + BFRAG; 483 tcpos = tcstart - record; 484 tcposend = tcend - record; 485 record = reallocf(record, newsize); 486 if (record == NULL) { 487 errno = ENOMEM; 488 if (myfd) 489 (void)_close(fd); 490 free(icap); 491 return (-2); 492 } 493 r_end = record + newsize; 494 rp = record + pos; 495 tcstart = record + tcpos; 496 tcend = record + tcposend; 497 } 498 499 /* 500 * Insert tc'ed record into our record. 501 */ 502 s = tcstart + newilen; 503 bcopy(tcend, s, rp - tcend); 504 bcopy(newicap, tcstart, newilen); 505 rp += diff; 506 free(icap); 507 508 /* 509 * Start scan on `:' so next cgetcap works properly 510 * (cgetcap always skips first field). 511 */ 512 scan = s-1; 513 } 514 515 } 516 /* 517 * Close file (if we opened it), give back any extra memory, and 518 * return capability, length and success. 519 */ 520 if (myfd) 521 (void)_close(fd); 522 *len = rp - record - 1; /* don't count NUL */ 523 if (r_end > rp) 524 if ((record = 525 reallocf(record, (size_t)(rp - record))) == NULL) { 526 errno = ENOMEM; 527 return (-2); 528 } 529 530 *cap = record; 531 if (tc_not_resolved) 532 return (1); 533 return (0); 534 } 535 536 static int 537 cdbget(capdbp, bp, name) 538 DB *capdbp; 539 char **bp, *name; 540 { 541 DBT key, data; 542 543 key.data = name; 544 key.size = strlen(name); 545 546 for (;;) { 547 /* Get the reference. */ 548 switch(capdbp->get(capdbp, &key, &data, 0)) { 549 case -1: 550 return (-2); 551 case 1: 552 return (-1); 553 } 554 555 /* If not an index to another record, leave. */ 556 if (((char *)data.data)[0] != SHADOW) 557 break; 558 559 key.data = (char *)data.data + 1; 560 key.size = data.size - 1; 561 } 562 563 *bp = (char *)data.data + 1; 564 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 565 } 566 567 /* 568 * Cgetmatch will return 0 if name is one of the names of the capability 569 * record buf, -1 if not. 570 */ 571 int 572 cgetmatch(buf, name) 573 char *buf, *name; 574 { 575 register char *np, *bp; 576 577 /* 578 * Start search at beginning of record. 579 */ 580 bp = buf; 581 for (;;) { 582 /* 583 * Try to match a record name. 584 */ 585 np = name; 586 for (;;) 587 if (*np == '\0') 588 if (*bp == '|' || *bp == ':' || *bp == '\0') 589 return (0); 590 else 591 break; 592 else 593 if (*bp++ != *np++) 594 break; 595 596 /* 597 * Match failed, skip to next name in record. 598 */ 599 bp--; /* a '|' or ':' may have stopped the match */ 600 for (;;) 601 if (*bp == '\0' || *bp == ':') 602 return (-1); /* match failed totally */ 603 else 604 if (*bp++ == '|') 605 break; /* found next name */ 606 } 607 } 608 609 610 611 612 613 int 614 cgetfirst(buf, db_array) 615 char **buf, **db_array; 616 { 617 (void)cgetclose(); 618 return (cgetnext(buf, db_array)); 619 } 620 621 static FILE *pfp; 622 static int slash; 623 static char **dbp; 624 625 int 626 cgetclose() 627 { 628 if (pfp != NULL) { 629 (void)fclose(pfp); 630 pfp = NULL; 631 } 632 dbp = NULL; 633 gottoprec = 0; 634 slash = 0; 635 return(0); 636 } 637 638 /* 639 * Cgetnext() gets either the first or next entry in the logical database 640 * specified by db_array. It returns 0 upon completion of the database, 1 641 * upon returning an entry with more remaining, and -1 if an error occurs. 642 */ 643 int 644 cgetnext(bp, db_array) 645 register char **bp; 646 char **db_array; 647 { 648 size_t len; 649 int done, hadreaderr, i, savederrno, status; 650 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE]; 651 u_int dummy; 652 653 if (dbp == NULL) 654 dbp = db_array; 655 656 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) { 657 (void)cgetclose(); 658 return (-1); 659 } 660 for(;;) { 661 if (toprec && !gottoprec) { 662 gottoprec = 1; 663 line = toprec; 664 } else { 665 line = fgetln(pfp, &len); 666 if (line == NULL && pfp) { 667 hadreaderr = ferror(pfp); 668 if (hadreaderr) 669 savederrno = errno; 670 fclose(pfp); 671 pfp = NULL; 672 if (hadreaderr) { 673 cgetclose(); 674 errno = savederrno; 675 return (-1); 676 } else { 677 if (*++dbp == NULL) { 678 (void)cgetclose(); 679 return (0); 680 } else if ((pfp = 681 fopen(*dbp, "r")) == NULL) { 682 (void)cgetclose(); 683 return (-1); 684 } else 685 continue; 686 } 687 } else 688 line[len - 1] = '\0'; 689 if (len == 1) { 690 slash = 0; 691 continue; 692 } 693 if (isspace((unsigned char)*line) || 694 *line == ':' || *line == '#' || slash) { 695 if (line[len - 2] == '\\') 696 slash = 1; 697 else 698 slash = 0; 699 continue; 700 } 701 if (line[len - 2] == '\\') 702 slash = 1; 703 else 704 slash = 0; 705 } 706 707 708 /* 709 * Line points to a name line. 710 */ 711 i = 0; 712 done = 0; 713 np = nbuf; 714 for (;;) { 715 for (cp = line; *cp != '\0'; cp++) { 716 if (*cp == ':') { 717 *np++ = ':'; 718 done = 1; 719 break; 720 } 721 if (*cp == '\\') 722 break; 723 *np++ = *cp; 724 } 725 if (done) { 726 *np = '\0'; 727 break; 728 } else { /* name field extends beyond the line */ 729 line = fgetln(pfp, &len); 730 if (line == NULL && pfp) { 731 /* Name extends beyond the EOF! */ 732 hadreaderr = ferror(pfp); 733 if (hadreaderr) 734 savederrno = errno; 735 fclose(pfp); 736 pfp = NULL; 737 if (hadreaderr) { 738 cgetclose(); 739 errno = savederrno; 740 return (-1); 741 } else { 742 cgetclose(); 743 return (-1); 744 } 745 } else 746 line[len - 1] = '\0'; 747 } 748 } 749 rp = buf; 750 for(cp = nbuf; *cp != '\0'; cp++) 751 if (*cp == '|' || *cp == ':') 752 break; 753 else 754 *rp++ = *cp; 755 756 *rp = '\0'; 757 /* 758 * XXX 759 * Last argument of getent here should be nbuf if we want true 760 * sequential access in the case of duplicates. 761 * With NULL, getent will return the first entry found 762 * rather than the duplicate entry record. This is a 763 * matter of semantics that should be resolved. 764 */ 765 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL); 766 if (status == -2 || status == -3) 767 (void)cgetclose(); 768 769 return (status + 1); 770 } 771 /* NOTREACHED */ 772 } 773 774 /* 775 * Cgetstr retrieves the value of the string capability cap from the 776 * capability record pointed to by buf. A pointer to a decoded, NUL 777 * terminated, malloc'd copy of the string is returned in the char * 778 * pointed to by str. The length of the string not including the trailing 779 * NUL is returned on success, -1 if the requested string capability 780 * couldn't be found, -2 if a system error was encountered (storage 781 * allocation failure). 782 */ 783 int 784 cgetstr(buf, cap, str) 785 char *buf, *cap; 786 char **str; 787 { 788 register u_int m_room; 789 register char *bp, *mp; 790 int len; 791 char *mem; 792 793 /* 794 * Find string capability cap 795 */ 796 bp = cgetcap(buf, cap, '='); 797 if (bp == NULL) 798 return (-1); 799 800 /* 801 * Conversion / storage allocation loop ... Allocate memory in 802 * chunks SFRAG in size. 803 */ 804 if ((mem = malloc(SFRAG)) == NULL) { 805 errno = ENOMEM; 806 return (-2); /* couldn't even allocate the first fragment */ 807 } 808 m_room = SFRAG; 809 mp = mem; 810 811 while (*bp != ':' && *bp != '\0') { 812 /* 813 * Loop invariants: 814 * There is always room for one more character in mem. 815 * Mp always points just past last character in mem. 816 * Bp always points at next character in buf. 817 */ 818 if (*bp == '^') { 819 bp++; 820 if (*bp == ':' || *bp == '\0') 821 break; /* drop unfinished escape */ 822 if (*bp == '?') { 823 *mp++ = '\177'; 824 bp++; 825 } else 826 *mp++ = *bp++ & 037; 827 } else if (*bp == '\\') { 828 bp++; 829 if (*bp == ':' || *bp == '\0') 830 break; /* drop unfinished escape */ 831 if ('0' <= *bp && *bp <= '7') { 832 register int n, i; 833 834 n = 0; 835 i = 3; /* maximum of three octal digits */ 836 do { 837 n = n * 8 + (*bp++ - '0'); 838 } while (--i && '0' <= *bp && *bp <= '7'); 839 *mp++ = n; 840 } 841 else switch (*bp++) { 842 case 'b': case 'B': 843 *mp++ = '\b'; 844 break; 845 case 't': case 'T': 846 *mp++ = '\t'; 847 break; 848 case 'n': case 'N': 849 *mp++ = '\n'; 850 break; 851 case 'f': case 'F': 852 *mp++ = '\f'; 853 break; 854 case 'r': case 'R': 855 *mp++ = '\r'; 856 break; 857 case 'e': case 'E': 858 *mp++ = ESC; 859 break; 860 case 'c': case 'C': 861 *mp++ = ':'; 862 break; 863 default: 864 /* 865 * Catches '\', '^', and 866 * everything else. 867 */ 868 *mp++ = *(bp-1); 869 break; 870 } 871 } else 872 *mp++ = *bp++; 873 m_room--; 874 875 /* 876 * Enforce loop invariant: if no room left in current 877 * buffer, try to get some more. 878 */ 879 if (m_room == 0) { 880 size_t size = mp - mem; 881 882 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 883 return (-2); 884 m_room = SFRAG; 885 mp = mem + size; 886 } 887 } 888 *mp++ = '\0'; /* loop invariant let's us do this */ 889 m_room--; 890 len = mp - mem - 1; 891 892 /* 893 * Give back any extra memory and return value and success. 894 */ 895 if (m_room != 0) 896 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 897 return (-2); 898 *str = mem; 899 return (len); 900 } 901 902 /* 903 * Cgetustr retrieves the value of the string capability cap from the 904 * capability record pointed to by buf. The difference between cgetustr() 905 * and cgetstr() is that cgetustr does not decode escapes but rather treats 906 * all characters literally. A pointer to a NUL terminated malloc'd 907 * copy of the string is returned in the char pointed to by str. The 908 * length of the string not including the trailing NUL is returned on success, 909 * -1 if the requested string capability couldn't be found, -2 if a system 910 * error was encountered (storage allocation failure). 911 */ 912 int 913 cgetustr(buf, cap, str) 914 char *buf, *cap, **str; 915 { 916 register u_int m_room; 917 register char *bp, *mp; 918 int len; 919 char *mem; 920 921 /* 922 * Find string capability cap 923 */ 924 if ((bp = cgetcap(buf, cap, '=')) == NULL) 925 return (-1); 926 927 /* 928 * Conversion / storage allocation loop ... Allocate memory in 929 * chunks SFRAG in size. 930 */ 931 if ((mem = malloc(SFRAG)) == NULL) { 932 errno = ENOMEM; 933 return (-2); /* couldn't even allocate the first fragment */ 934 } 935 m_room = SFRAG; 936 mp = mem; 937 938 while (*bp != ':' && *bp != '\0') { 939 /* 940 * Loop invariants: 941 * There is always room for one more character in mem. 942 * Mp always points just past last character in mem. 943 * Bp always points at next character in buf. 944 */ 945 *mp++ = *bp++; 946 m_room--; 947 948 /* 949 * Enforce loop invariant: if no room left in current 950 * buffer, try to get some more. 951 */ 952 if (m_room == 0) { 953 size_t size = mp - mem; 954 955 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 956 return (-2); 957 m_room = SFRAG; 958 mp = mem + size; 959 } 960 } 961 *mp++ = '\0'; /* loop invariant let's us do this */ 962 m_room--; 963 len = mp - mem - 1; 964 965 /* 966 * Give back any extra memory and return value and success. 967 */ 968 if (m_room != 0) 969 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 970 return (-2); 971 *str = mem; 972 return (len); 973 } 974 975 /* 976 * Cgetnum retrieves the value of the numeric capability cap from the 977 * capability record pointed to by buf. The numeric value is returned in 978 * the long pointed to by num. 0 is returned on success, -1 if the requested 979 * numeric capability couldn't be found. 980 */ 981 int 982 cgetnum(buf, cap, num) 983 char *buf, *cap; 984 long *num; 985 { 986 register long n; 987 register int base, digit; 988 register char *bp; 989 990 /* 991 * Find numeric capability cap 992 */ 993 bp = cgetcap(buf, cap, '#'); 994 if (bp == NULL) 995 return (-1); 996 997 /* 998 * Look at value and determine numeric base: 999 * 0x... or 0X... hexadecimal, 1000 * else 0... octal, 1001 * else decimal. 1002 */ 1003 if (*bp == '0') { 1004 bp++; 1005 if (*bp == 'x' || *bp == 'X') { 1006 bp++; 1007 base = 16; 1008 } else 1009 base = 8; 1010 } else 1011 base = 10; 1012 1013 /* 1014 * Conversion loop ... 1015 */ 1016 n = 0; 1017 for (;;) { 1018 if ('0' <= *bp && *bp <= '9') 1019 digit = *bp - '0'; 1020 else if ('a' <= *bp && *bp <= 'f') 1021 digit = 10 + *bp - 'a'; 1022 else if ('A' <= *bp && *bp <= 'F') 1023 digit = 10 + *bp - 'A'; 1024 else 1025 break; 1026 1027 if (digit >= base) 1028 break; 1029 1030 n = n * base + digit; 1031 bp++; 1032 } 1033 1034 /* 1035 * Return value and success. 1036 */ 1037 *num = n; 1038 return (0); 1039 } 1040 1041 1042 /* 1043 * Compare name field of record. 1044 */ 1045 static int 1046 nfcmp(nf, rec) 1047 char *nf, *rec; 1048 { 1049 char *cp, tmp; 1050 int ret; 1051 1052 for (cp = rec; *cp != ':'; cp++) 1053 ; 1054 1055 tmp = *(cp + 1); 1056 *(cp + 1) = '\0'; 1057 ret = strcmp(nf, rec); 1058 *(cp + 1) = tmp; 1059 1060 return (ret); 1061 } 1062