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