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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)getcap.c 8.3 (Berkeley) 3/25/94"; 35 #endif /* LIBC_SCCS and not lint */ 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "namespace.h" 40 #include <sys/types.h> 41 42 #include <ctype.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <limits.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include "un-namespace.h" 51 52 #include <db.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 **, const char *); 69 static int getent(char **, u_int *, char **, int, const 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(const char *ent) 79 { 80 if (ent == NULL) { 81 if (toprec) 82 free(toprec); 83 toprec = NULL; 84 topreclen = 0; 85 return (0); 86 } 87 topreclen = strlen(ent); 88 if ((toprec = malloc (topreclen + 1)) == NULL) { 89 errno = ENOMEM; 90 return (-1); 91 } 92 gottoprec = 0; 93 (void)strcpy(toprec, ent); 94 return (0); 95 } 96 97 /* 98 * Cgetcap searches the capability record buf for the capability cap with 99 * type `type'. A pointer to the value of cap is returned on success, NULL 100 * if the requested capability couldn't be found. 101 * 102 * Specifying a type of ':' means that nothing should follow cap (:cap:). 103 * In this case a pointer to the terminating ':' or NUL will be returned if 104 * cap is found. 105 * 106 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator) 107 * return NULL. 108 */ 109 char * 110 cgetcap(char *buf, const char *cap, int type) 111 { 112 char *bp; 113 const char *cp; 114 115 bp = buf; 116 for (;;) { 117 /* 118 * Skip past the current capability field - it's either the 119 * name field if this is the first time through the loop, or 120 * the remainder of a field whose name failed to match cap. 121 */ 122 for (;;) 123 if (*bp == '\0') 124 return (NULL); 125 else 126 if (*bp++ == ':') 127 break; 128 129 /* 130 * Try to match (cap, type) in buf. 131 */ 132 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++) 133 continue; 134 if (*cp != '\0') 135 continue; 136 if (*bp == '@') 137 return (NULL); 138 if (type == ':') { 139 if (*bp != '\0' && *bp != ':') 140 continue; 141 return(bp); 142 } 143 if (*bp != type) 144 continue; 145 bp++; 146 return (*bp == '@' ? NULL : bp); 147 } 148 /* NOTREACHED */ 149 } 150 151 /* 152 * Cgetent extracts the capability record name from the NULL terminated file 153 * array db_array and returns a pointer to a malloc'd copy of it in buf. 154 * Buf must be retained through all subsequent calls to cgetcap, cgetnum, 155 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success, 156 * -1 if the requested record couldn't be found, -2 if a system error was 157 * encountered (couldn't open/read a file, etc.), and -3 if a potential 158 * reference loop is detected. 159 */ 160 int 161 cgetent(char **buf, char **db_array, const char *name) 162 { 163 u_int dummy; 164 165 return (getent(buf, &dummy, db_array, -1, name, 0, NULL)); 166 } 167 168 /* 169 * Getent implements the functions of cgetent. If fd is non-negative, 170 * *db_array has already been opened and fd is the open file descriptor. We 171 * do this to save time and avoid using up file descriptors for tc= 172 * recursions. 173 * 174 * Getent returns the same success/failure codes as cgetent. On success, a 175 * pointer to a malloc'ed capability record with all tc= capabilities fully 176 * expanded and its length (not including trailing ASCII NUL) are left in 177 * *cap and *len. 178 * 179 * Basic algorithm: 180 * + Allocate memory incrementally as needed in chunks of size BFRAG 181 * for capability buffer. 182 * + Recurse for each tc=name and interpolate result. Stop when all 183 * names interpolated, a name can't be found, or depth exceeds 184 * MAX_RECURSION. 185 */ 186 static int 187 getent(char **cap, u_int *len, char **db_array, int fd, const char *name, 188 int depth, char *nfield) 189 { 190 DB *capdbp; 191 char *r_end, *rp, **db_p; 192 int myfd, eof, foundit, retval; 193 char *record, *cbuf; 194 int tc_not_resolved; 195 char pbuf[_POSIX_PATH_MAX]; 196 197 /* 198 * Return with ``loop detected'' error if we've recursed more than 199 * MAX_RECURSION times. 200 */ 201 if (depth > MAX_RECURSION) 202 return (-3); 203 204 /* 205 * Check if we have a top record from cgetset(). 206 */ 207 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) { 208 if ((record = malloc (topreclen + BFRAG)) == NULL) { 209 errno = ENOMEM; 210 return (-2); 211 } 212 (void)strcpy(record, toprec); 213 myfd = 0; 214 db_p = db_array; 215 rp = record + topreclen + 1; 216 r_end = rp + BFRAG; 217 goto tc_exp; 218 } 219 /* 220 * Allocate first chunk of memory. 221 */ 222 if ((record = malloc(BFRAG)) == NULL) { 223 errno = ENOMEM; 224 return (-2); 225 } 226 r_end = record + BFRAG; 227 foundit = 0; 228 /* 229 * Loop through database array until finding the record. 230 */ 231 232 for (db_p = db_array; *db_p != NULL; db_p++) { 233 eof = 0; 234 235 /* 236 * Open database if not already open. 237 */ 238 239 if (fd >= 0) { 240 (void)lseek(fd, (off_t)0, SEEK_SET); 241 myfd = 0; 242 } else { 243 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p); 244 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0)) 245 != NULL) { 246 free(record); 247 retval = cdbget(capdbp, &record, name); 248 if (retval < 0) { 249 /* no record available */ 250 (void)capdbp->close(capdbp); 251 return (retval); 252 } 253 /* save the data; close frees it */ 254 cbuf = strdup(record); 255 if (capdbp->close(capdbp) < 0) { 256 free(cbuf); 257 return (-2); 258 } 259 if (cbuf == NULL) { 260 errno = ENOMEM; 261 return (-2); 262 } 263 *len = strlen(cbuf); 264 *cap = cbuf; 265 return (retval); 266 } else { 267 fd = _open(*db_p, O_RDONLY, 0); 268 if (fd < 0) 269 continue; 270 myfd = 1; 271 } 272 } 273 /* 274 * Find the requested capability record ... 275 */ 276 { 277 char buf[BUFSIZ]; 278 char *b_end, *bp; 279 int c; 280 281 /* 282 * Loop invariants: 283 * There is always room for one more character in record. 284 * R_end always points just past end of record. 285 * Rp always points just past last character in record. 286 * B_end always points just past last character in buf. 287 * Bp always points at next character in buf. 288 */ 289 b_end = buf; 290 bp = buf; 291 for (;;) { 292 293 /* 294 * Read in a line implementing (\, newline) 295 * line continuation. 296 */ 297 rp = record; 298 for (;;) { 299 if (bp >= b_end) { 300 int n; 301 302 n = _read(fd, buf, sizeof(buf)); 303 if (n <= 0) { 304 if (myfd) 305 (void)_close(fd); 306 if (n < 0) { 307 free(record); 308 return (-2); 309 } else { 310 fd = -1; 311 eof = 1; 312 break; 313 } 314 } 315 b_end = buf+n; 316 bp = buf; 317 } 318 319 c = *bp++; 320 if (c == '\n') { 321 if (rp > record && *(rp-1) == '\\') { 322 rp--; 323 continue; 324 } else 325 break; 326 } 327 *rp++ = c; 328 329 /* 330 * Enforce loop invariant: if no room 331 * left in record buffer, try to get 332 * some more. 333 */ 334 if (rp >= r_end) { 335 u_int pos; 336 size_t newsize; 337 338 pos = rp - record; 339 newsize = r_end - record + BFRAG; 340 record = reallocf(record, newsize); 341 if (record == NULL) { 342 errno = ENOMEM; 343 if (myfd) 344 (void)_close(fd); 345 return (-2); 346 } 347 r_end = record + newsize; 348 rp = record + pos; 349 } 350 } 351 /* loop invariant let's us do this */ 352 *rp++ = '\0'; 353 354 /* 355 * If encountered eof check next file. 356 */ 357 if (eof) 358 break; 359 360 /* 361 * Toss blank lines and comments. 362 */ 363 if (*record == '\0' || *record == '#') 364 continue; 365 366 /* 367 * See if this is the record we want ... 368 */ 369 if (cgetmatch(record, name) == 0) { 370 if (nfield == NULL || !nfcmp(nfield, record)) { 371 foundit = 1; 372 break; /* found it! */ 373 } 374 } 375 } 376 } 377 if (foundit) 378 break; 379 } 380 381 if (!foundit) { 382 free(record); 383 return (-1); 384 } 385 386 /* 387 * Got the capability record, but now we have to expand all tc=name 388 * references in it ... 389 */ 390 tc_exp: { 391 char *newicap, *s; 392 int newilen; 393 u_int ilen; 394 int diff, iret, tclen; 395 char *icap, *scan, *tc, *tcstart, *tcend; 396 397 /* 398 * Loop invariants: 399 * There is room for one more character in record. 400 * R_end points just past end of record. 401 * Rp points just past last character in record. 402 * Scan points at remainder of record that needs to be 403 * scanned for tc=name constructs. 404 */ 405 scan = record; 406 tc_not_resolved = 0; 407 for (;;) { 408 if ((tc = cgetcap(scan, "tc", '=')) == NULL) 409 break; 410 411 /* 412 * Find end of tc=name and stomp on the trailing `:' 413 * (if present) so we can use it to call ourselves. 414 */ 415 s = tc; 416 for (;;) 417 if (*s == '\0') 418 break; 419 else 420 if (*s++ == ':') { 421 *(s - 1) = '\0'; 422 break; 423 } 424 tcstart = tc - 3; 425 tclen = s - tcstart; 426 tcend = s; 427 428 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1, 429 NULL); 430 newicap = icap; /* Put into a register. */ 431 newilen = ilen; 432 if (iret != 0) { 433 /* an error */ 434 if (iret < -1) { 435 if (myfd) 436 (void)_close(fd); 437 free(record); 438 return (iret); 439 } 440 if (iret == 1) 441 tc_not_resolved = 1; 442 /* couldn't resolve tc */ 443 if (iret == -1) { 444 *(s - 1) = ':'; 445 scan = s - 1; 446 tc_not_resolved = 1; 447 continue; 448 449 } 450 } 451 /* not interested in name field of tc'ed record */ 452 s = newicap; 453 for (;;) 454 if (*s == '\0') 455 break; 456 else 457 if (*s++ == ':') 458 break; 459 newilen -= s - newicap; 460 newicap = s; 461 462 /* make sure interpolated record is `:'-terminated */ 463 s += newilen; 464 if (*(s-1) != ':') { 465 *s = ':'; /* overwrite NUL with : */ 466 newilen++; 467 } 468 469 /* 470 * Make sure there's enough room to insert the 471 * new record. 472 */ 473 diff = newilen - tclen; 474 if (diff >= r_end - rp) { 475 u_int pos, tcpos, tcposend; 476 size_t newsize; 477 478 pos = rp - record; 479 newsize = r_end - record + diff + BFRAG; 480 tcpos = tcstart - record; 481 tcposend = tcend - record; 482 record = reallocf(record, newsize); 483 if (record == NULL) { 484 errno = ENOMEM; 485 if (myfd) 486 (void)_close(fd); 487 free(icap); 488 return (-2); 489 } 490 r_end = record + newsize; 491 rp = record + pos; 492 tcstart = record + tcpos; 493 tcend = record + tcposend; 494 } 495 496 /* 497 * Insert tc'ed record into our record. 498 */ 499 s = tcstart + newilen; 500 bcopy(tcend, s, rp - tcend); 501 bcopy(newicap, tcstart, newilen); 502 rp += diff; 503 free(icap); 504 505 /* 506 * Start scan on `:' so next cgetcap works properly 507 * (cgetcap always skips first field). 508 */ 509 scan = s-1; 510 } 511 512 } 513 /* 514 * Close file (if we opened it), give back any extra memory, and 515 * return capability, length and success. 516 */ 517 if (myfd) 518 (void)_close(fd); 519 *len = rp - record - 1; /* don't count NUL */ 520 if (r_end > rp) 521 if ((record = 522 reallocf(record, (size_t)(rp - record))) == NULL) { 523 errno = ENOMEM; 524 return (-2); 525 } 526 527 *cap = record; 528 if (tc_not_resolved) 529 return (1); 530 return (0); 531 } 532 533 static int 534 cdbget(DB *capdbp, char **bp, const char *name) 535 { 536 DBT key, data; 537 char *namebuf; 538 539 namebuf = strdup(name); 540 if (namebuf == NULL) 541 return (-2); 542 key.data = namebuf; 543 key.size = strlen(namebuf); 544 545 for (;;) { 546 /* Get the reference. */ 547 switch(capdbp->get(capdbp, &key, &data, 0)) { 548 case -1: 549 free(namebuf); 550 return (-2); 551 case 1: 552 free(namebuf); 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 free(namebuf); 566 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 567 } 568 569 /* 570 * Cgetmatch will return 0 if name is one of the names of the capability 571 * record buf, -1 if not. 572 */ 573 int 574 cgetmatch(const char *buf, const char *name) 575 { 576 const char *np, *bp; 577 578 if (name == NULL || *name == '\0') 579 return -1; 580 581 /* 582 * Start search at beginning of record. 583 */ 584 bp = buf; 585 for (;;) { 586 /* 587 * Try to match a record name. 588 */ 589 np = name; 590 for (;;) 591 if (*np == '\0') 592 if (*bp == '|' || *bp == ':' || *bp == '\0') 593 return (0); 594 else 595 break; 596 else 597 if (*bp++ != *np++) 598 break; 599 600 /* 601 * Match failed, skip to next name in record. 602 */ 603 bp--; /* a '|' or ':' may have stopped the match */ 604 for (;;) 605 if (*bp == '\0' || *bp == ':') 606 return (-1); /* match failed totally */ 607 else 608 if (*bp++ == '|') 609 break; /* found next name */ 610 } 611 } 612 613 614 615 616 617 int 618 cgetfirst(char **buf, char **db_array) 619 { 620 (void)cgetclose(); 621 return (cgetnext(buf, db_array)); 622 } 623 624 static FILE *pfp; 625 static int slash; 626 static char **dbp; 627 628 int 629 cgetclose(void) 630 { 631 if (pfp != NULL) { 632 (void)fclose(pfp); 633 pfp = NULL; 634 } 635 dbp = NULL; 636 gottoprec = 0; 637 slash = 0; 638 return(0); 639 } 640 641 /* 642 * Cgetnext() gets either the first or next entry in the logical database 643 * specified by db_array. It returns 0 upon completion of the database, 1 644 * upon returning an entry with more remaining, and -1 if an error occurs. 645 */ 646 int 647 cgetnext(char **bp, char **db_array) 648 { 649 size_t len; 650 int done, hadreaderr, savederrno, status; 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 hadreaderr = ferror(pfp); 669 if (hadreaderr) 670 savederrno = errno; 671 fclose(pfp); 672 pfp = NULL; 673 if (hadreaderr) { 674 cgetclose(); 675 errno = savederrno; 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((unsigned char)*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 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(char *buf, const char *cap, char **str) 785 { 786 u_int m_room; 787 char *bp, *mp; 788 int len; 789 char *mem; 790 791 /* 792 * Find string capability cap 793 */ 794 bp = cgetcap(buf, cap, '='); 795 if (bp == NULL) 796 return (-1); 797 798 /* 799 * Conversion / storage allocation loop ... Allocate memory in 800 * chunks SFRAG in size. 801 */ 802 if ((mem = malloc(SFRAG)) == NULL) { 803 errno = ENOMEM; 804 return (-2); /* couldn't even allocate the first fragment */ 805 } 806 m_room = SFRAG; 807 mp = mem; 808 809 while (*bp != ':' && *bp != '\0') { 810 /* 811 * Loop invariants: 812 * There is always room for one more character in mem. 813 * Mp always points just past last character in mem. 814 * Bp always points at next character in buf. 815 */ 816 if (*bp == '^') { 817 bp++; 818 if (*bp == ':' || *bp == '\0') 819 break; /* drop unfinished escape */ 820 if (*bp == '?') { 821 *mp++ = '\177'; 822 bp++; 823 } else 824 *mp++ = *bp++ & 037; 825 } else if (*bp == '\\') { 826 bp++; 827 if (*bp == ':' || *bp == '\0') 828 break; /* drop unfinished escape */ 829 if ('0' <= *bp && *bp <= '7') { 830 int n, i; 831 832 n = 0; 833 i = 3; /* maximum of three octal digits */ 834 do { 835 n = n * 8 + (*bp++ - '0'); 836 } while (--i && '0' <= *bp && *bp <= '7'); 837 *mp++ = n; 838 } 839 else switch (*bp++) { 840 case 'b': case 'B': 841 *mp++ = '\b'; 842 break; 843 case 't': case 'T': 844 *mp++ = '\t'; 845 break; 846 case 'n': case 'N': 847 *mp++ = '\n'; 848 break; 849 case 'f': case 'F': 850 *mp++ = '\f'; 851 break; 852 case 'r': case 'R': 853 *mp++ = '\r'; 854 break; 855 case 'e': case 'E': 856 *mp++ = ESC; 857 break; 858 case 'c': case 'C': 859 *mp++ = ':'; 860 break; 861 default: 862 /* 863 * Catches '\', '^', and 864 * everything else. 865 */ 866 *mp++ = *(bp-1); 867 break; 868 } 869 } else 870 *mp++ = *bp++; 871 m_room--; 872 873 /* 874 * Enforce loop invariant: if no room left in current 875 * buffer, try to get some more. 876 */ 877 if (m_room == 0) { 878 size_t size = mp - mem; 879 880 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 881 return (-2); 882 m_room = SFRAG; 883 mp = mem + size; 884 } 885 } 886 *mp++ = '\0'; /* loop invariant let's us do this */ 887 m_room--; 888 len = mp - mem - 1; 889 890 /* 891 * Give back any extra memory and return value and success. 892 */ 893 if (m_room != 0) 894 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 895 return (-2); 896 *str = mem; 897 return (len); 898 } 899 900 /* 901 * Cgetustr retrieves the value of the string capability cap from the 902 * capability record pointed to by buf. The difference between cgetustr() 903 * and cgetstr() is that cgetustr does not decode escapes but rather treats 904 * all characters literally. A pointer to a NUL terminated malloc'd 905 * copy of the string is returned in the char pointed to by str. The 906 * length of the string not including the trailing NUL is returned on success, 907 * -1 if the requested string capability couldn't be found, -2 if a system 908 * error was encountered (storage allocation failure). 909 */ 910 int 911 cgetustr(char *buf, const char *cap, char **str) 912 { 913 u_int m_room; 914 char *bp, *mp; 915 int len; 916 char *mem; 917 918 /* 919 * Find string capability cap 920 */ 921 if ((bp = cgetcap(buf, cap, '=')) == NULL) 922 return (-1); 923 924 /* 925 * Conversion / storage allocation loop ... Allocate memory in 926 * chunks SFRAG in size. 927 */ 928 if ((mem = malloc(SFRAG)) == NULL) { 929 errno = ENOMEM; 930 return (-2); /* couldn't even allocate the first fragment */ 931 } 932 m_room = SFRAG; 933 mp = mem; 934 935 while (*bp != ':' && *bp != '\0') { 936 /* 937 * Loop invariants: 938 * There is always room for one more character in mem. 939 * Mp always points just past last character in mem. 940 * Bp always points at next character in buf. 941 */ 942 *mp++ = *bp++; 943 m_room--; 944 945 /* 946 * Enforce loop invariant: if no room left in current 947 * buffer, try to get some more. 948 */ 949 if (m_room == 0) { 950 size_t size = mp - mem; 951 952 if ((mem = reallocf(mem, size + SFRAG)) == NULL) 953 return (-2); 954 m_room = SFRAG; 955 mp = mem + size; 956 } 957 } 958 *mp++ = '\0'; /* loop invariant let's us do this */ 959 m_room--; 960 len = mp - mem - 1; 961 962 /* 963 * Give back any extra memory and return value and success. 964 */ 965 if (m_room != 0) 966 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL) 967 return (-2); 968 *str = mem; 969 return (len); 970 } 971 972 /* 973 * Cgetnum retrieves the value of the numeric capability cap from the 974 * capability record pointed to by buf. The numeric value is returned in 975 * the long pointed to by num. 0 is returned on success, -1 if the requested 976 * numeric capability couldn't be found. 977 */ 978 int 979 cgetnum(char *buf, const char *cap, long *num) 980 { 981 long n; 982 int base, digit; 983 char *bp; 984 985 /* 986 * Find numeric capability cap 987 */ 988 bp = cgetcap(buf, cap, '#'); 989 if (bp == NULL) 990 return (-1); 991 992 /* 993 * Look at value and determine numeric base: 994 * 0x... or 0X... hexadecimal, 995 * else 0... octal, 996 * else decimal. 997 */ 998 if (*bp == '0') { 999 bp++; 1000 if (*bp == 'x' || *bp == 'X') { 1001 bp++; 1002 base = 16; 1003 } else 1004 base = 8; 1005 } else 1006 base = 10; 1007 1008 /* 1009 * Conversion loop ... 1010 */ 1011 n = 0; 1012 for (;;) { 1013 if ('0' <= *bp && *bp <= '9') 1014 digit = *bp - '0'; 1015 else if ('a' <= *bp && *bp <= 'f') 1016 digit = 10 + *bp - 'a'; 1017 else if ('A' <= *bp && *bp <= 'F') 1018 digit = 10 + *bp - 'A'; 1019 else 1020 break; 1021 1022 if (digit >= base) 1023 break; 1024 1025 n = n * base + digit; 1026 bp++; 1027 } 1028 1029 /* 1030 * Return value and success. 1031 */ 1032 *num = n; 1033 return (0); 1034 } 1035 1036 1037 /* 1038 * Compare name field of record. 1039 */ 1040 static int 1041 nfcmp(char *nf, char *rec) 1042 { 1043 char *cp, tmp; 1044 int ret; 1045 1046 for (cp = rec; *cp != ':'; cp++) 1047 ; 1048 1049 tmp = *(cp + 1); 1050 *(cp + 1) = '\0'; 1051 ret = strcmp(nf, rec); 1052 *(cp + 1) = tmp; 1053 1054 return (ret); 1055 } 1056