getcap.c revision 108312
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) 38static 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: head/lib/libc/gen/getcap.c 108312 2002-12-27 08:43:40Z alfred $"); 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 68static size_t topreclen; /* toprec length */ 69static char *toprec; /* Additional record specified by cgetset() */ 70static int gottoprec; /* Flag indicating retrieval of toprecord */ 71 72static int cdbget(DB *, char **, const char *); 73static int getent(char **, u_int *, char **, int, const char *, int, char *); 74static 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 */ 81int 82cgetset(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 */ 113char * 114cgetcap(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 */ 164int 165cgetent(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 */ 190static int 191getent(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 */ 392tc_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 535static int 536cdbget(DB *capdbp, char **bp, const char *name) 537{ 538 DBT key, data; 539 char *namebuf; 540 541 namebuf = strdup(name); 542 if (namebuf == NULL) 543 return (-2); 544 key.data = namebuf; 545 key.size = strlen(namebuf); 546 547 for (;;) { 548 /* Get the reference. */ 549 switch(capdbp->get(capdbp, &key, &data, 0)) { 550 case -1: 551 free(namebuf); 552 return (-2); 553 case 1: 554 free(namebuf); 555 return (-1); 556 } 557 558 /* If not an index to another record, leave. */ 559 if (((char *)data.data)[0] != SHADOW) 560 break; 561 562 key.data = (char *)data.data + 1; 563 key.size = data.size - 1; 564 } 565 566 *bp = (char *)data.data + 1; 567 free(namebuf); 568 return (((char *)(data.data))[0] == TCERR ? 1 : 0); 569} 570 571/* 572 * Cgetmatch will return 0 if name is one of the names of the capability 573 * record buf, -1 if not. 574 */ 575int 576cgetmatch(const char *buf, const char *name) 577{ 578 const char *np, *bp; 579 580 /* 581 * Start search at beginning of record. 582 */ 583 bp = buf; 584 for (;;) { 585 /* 586 * Try to match a record name. 587 */ 588 np = name; 589 for (;;) 590 if (*np == '\0') 591 if (*bp == '|' || *bp == ':' || *bp == '\0') 592 return (0); 593 else 594 break; 595 else 596 if (*bp++ != *np++) 597 break; 598 599 /* 600 * Match failed, skip to next name in record. 601 */ 602 bp--; /* a '|' or ':' may have stopped the match */ 603 for (;;) 604 if (*bp == '\0' || *bp == ':') 605 return (-1); /* match failed totally */ 606 else 607 if (*bp++ == '|') 608 break; /* found next name */ 609 } 610} 611 612 613 614 615 616int 617cgetfirst(char **buf, char **db_array) 618{ 619 (void)cgetclose(); 620 return (cgetnext(buf, db_array)); 621} 622 623static FILE *pfp; 624static int slash; 625static char **dbp; 626 627int 628cgetclose(void) 629{ 630 if (pfp != NULL) { 631 (void)fclose(pfp); 632 pfp = NULL; 633 } 634 dbp = NULL; 635 gottoprec = 0; 636 slash = 0; 637 return(0); 638} 639 640/* 641 * Cgetnext() gets either the first or next entry in the logical database 642 * specified by db_array. It returns 0 upon completion of the database, 1 643 * upon returning an entry with more remaining, and -1 if an error occurs. 644 */ 645int 646cgetnext(char **bp, 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 */ 783int 784cgetstr(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 */ 910int 911cgetustr(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 */ 978int 979cgetnum(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 */ 1040static int 1041nfcmp(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