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getcap.c revision 1.4
      1 /*-
      2  * Copyright (c) 1992 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to Berkeley by
      6  * Casey Leedom of Lawrence Livermore National Laboratory.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 /*static char *sccsid = "from: @(#)getcap.c	5.15 (Berkeley) 3/19/93";*/
     39 static char *rcsid = "$Id: getcap.c,v 1.4 1993/08/26 00:44:35 jtc Exp $";
     40 #endif /* LIBC_SCCS and not lint */
     41 
     42 #include <sys/types.h>
     43 
     44 #include <ctype.h>
     45 #include <db.h>
     46 #include <errno.h>
     47 #include <fcntl.h>
     48 #include <limits.h>
     49 #include <stdio.h>
     50 #include <stdlib.h>
     51 #include <string.h>
     52 #include <unistd.h>
     53 
     54 #define	BFRAG		1024
     55 #define	BSIZE		1024
     56 #define	ESC		('[' & 037)	/* ASCII ESC */
     57 #define	MAX_RECURSION	32		/* maximum getent recursion */
     58 #define	SFRAG		100		/* cgetstr mallocs in SFRAG chunks */
     59 
     60 #define RECOK	(char)0
     61 #define TCERR	(char)1
     62 #define	SHADOW	(char)2
     63 
     64 static size_t	 topreclen;	/* toprec length */
     65 static char	*toprec;	/* Additional record specified by cgetset() */
     66 static int	 gottoprec;	/* Flag indicating retrieval of toprecord */
     67 
     68 static int	cdbget __P((DB *, char **, char *));
     69 static int 	getent __P((char **, u_int *, char **, int, char *, int, char *));
     70 static int	nfcmp __P((char *, char *));
     71 
     72 /*
     73  * Cgetset() allows the addition of a user specified buffer to be added
     74  * to the database array, in effect "pushing" the buffer on top of the
     75  * virtual database. 0 is returned on success, -1 on failure.
     76  */
     77 int
     78 cgetset(ent)
     79 	char *ent;
     80 {
     81 	if (ent == NULL) {
     82 		if (toprec)
     83 			free(toprec);
     84                 toprec = NULL;
     85                 topreclen = 0;
     86                 return (0);
     87         }
     88         topreclen = strlen(ent);
     89         if ((toprec = malloc (topreclen + 1)) == NULL) {
     90 		errno = ENOMEM;
     91                 return (-1);
     92 	}
     93 	gottoprec = 0;
     94         (void)strcpy(toprec, ent);
     95         return (0);
     96 }
     97 
     98 /*
     99  * Cgetcap searches the capability record buf for the capability cap with
    100  * type `type'.  A pointer to the value of cap is returned on success, NULL
    101  * if the requested capability couldn't be found.
    102  *
    103  * Specifying a type of ':' means that nothing should follow cap (:cap:).
    104  * In this case a pointer to the terminating ':' or NUL will be returned if
    105  * cap is found.
    106  *
    107  * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
    108  * return NULL.
    109  */
    110 char *
    111 cgetcap(buf, cap, type)
    112 	char *buf, *cap;
    113 	int type;
    114 {
    115 	register char *bp, *cp;
    116 
    117 	bp = buf;
    118 	for (;;) {
    119 		/*
    120 		 * Skip past the current capability field - it's either the
    121 		 * name field if this is the first time through the loop, or
    122 		 * the remainder of a field whose name failed to match cap.
    123 		 */
    124 		for (;;)
    125 			if (*bp == '\0')
    126 				return (NULL);
    127 			else
    128 				if (*bp++ == ':')
    129 					break;
    130 
    131 		/*
    132 		 * Try to match (cap, type) in buf.
    133 		 */
    134 		for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
    135 			continue;
    136 		if (*cp != '\0')
    137 			continue;
    138 		if (*bp == '@')
    139 			return (NULL);
    140 		if (type == ':') {
    141 			if (*bp != '\0' && *bp != ':')
    142 				continue;
    143 			return(bp);
    144 		}
    145 		if (*bp != type)
    146 			continue;
    147 		bp++;
    148 		return (*bp == '@' ? NULL : bp);
    149 	}
    150 	/* NOTREACHED */
    151 }
    152 
    153 /*
    154  * Cgetent extracts the capability record name from the NULL terminated file
    155  * array db_array and returns a pointer to a malloc'd copy of it in buf.
    156  * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
    157  * cgetflag, and cgetstr, but may then be free'd.  0 is returned on success,
    158  * -1 if the requested record couldn't be found, -2 if a system error was
    159  * encountered (couldn't open/read a file, etc.), and -3 if a potential
    160  * reference loop is detected.
    161  */
    162 int
    163 cgetent(buf, db_array, name)
    164 	char **buf, **db_array, *name;
    165 {
    166 	u_int dummy;
    167 
    168 	return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
    169 }
    170 
    171 /*
    172  * Getent implements the functions of cgetent.  If fd is non-negative,
    173  * *db_array has already been opened and fd is the open file descriptor.  We
    174  * do this to save time and avoid using up file descriptors for tc=
    175  * recursions.
    176  *
    177  * Getent returns the same success/failure codes as cgetent.  On success, a
    178  * pointer to a malloc'ed capability record with all tc= capabilities fully
    179  * expanded and its length (not including trailing ASCII NUL) are left in
    180  * *cap and *len.
    181  *
    182  * Basic algorithm:
    183  *	+ Allocate memory incrementally as needed in chunks of size BFRAG
    184  *	  for capability buffer.
    185  *	+ Recurse for each tc=name and interpolate result.  Stop when all
    186  *	  names interpolated, a name can't be found, or depth exceeds
    187  *	  MAX_RECURSION.
    188  */
    189 static int
    190 getent(cap, len, db_array, fd, name, depth, nfield)
    191 	char **cap, **db_array, *name, *nfield;
    192 	u_int *len;
    193 	int fd, depth;
    194 {
    195 	DB *capdbp;
    196 	DBT key, data;
    197 	register char *r_end, *rp, **db_p;
    198 	int myfd, eof, foundit, retval;
    199 	char *record;
    200 	int tc_not_resolved;
    201 	char pbuf[_POSIX_PATH_MAX];
    202 
    203 	/*
    204 	 * Return with ``loop detected'' error if we've recursed more than
    205 	 * MAX_RECURSION times.
    206 	 */
    207 	if (depth > MAX_RECURSION)
    208 		return (-3);
    209 
    210 	/*
    211 	 * Check if we have a top record from cgetset().
    212          */
    213 	if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
    214 		if ((record = malloc (topreclen + BFRAG)) == NULL) {
    215 			errno = ENOMEM;
    216 			return (-2);
    217 		}
    218 		(void)strcpy(record, toprec);
    219 		myfd = 0;
    220 		db_p = db_array;
    221 		rp = record + topreclen + 1;
    222 		r_end = rp + BFRAG;
    223 		goto tc_exp;
    224 	}
    225 	/*
    226 	 * Allocate first chunk of memory.
    227 	 */
    228 	if ((record = malloc(BFRAG)) == NULL) {
    229 		errno = ENOMEM;
    230 		return (-2);
    231 	}
    232 	r_end = record + BFRAG;
    233 	foundit = 0;
    234 	/*
    235 	 * Loop through database array until finding the record.
    236 	 */
    237 
    238 	for (db_p = db_array; *db_p != NULL; db_p++) {
    239 		eof = 0;
    240 
    241 		/*
    242 		 * Open database if not already open.
    243 		 */
    244 
    245 		if (fd >= 0) {
    246 			(void)lseek(fd, (off_t)0, L_SET);
    247 			myfd = 0;
    248 		} else {
    249 			(void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
    250 			if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
    251 			     != NULL) {
    252 				free(record);
    253 				retval = cdbget(capdbp, &record, name);
    254 				if (capdbp->close(capdbp) < 0)
    255 					return (-2);
    256 				*len = strlen(record);
    257 				*cap = malloc(*len + 1);
    258 				memmove(*cap, record, *len + 1);
    259 				return (retval);
    260 			} else {
    261 				fd = open(*db_p, O_RDONLY, 0);
    262 				if (fd < 0) {
    263 					/* No error on unfound file. */
    264 					if (errno == ENOENT)
    265 						continue;
    266 					free(record);
    267 					return (-2);
    268 				}
    269 				myfd = 1;
    270 			}
    271 		}
    272 		/*
    273 		 * Find the requested capability record ...
    274 		 */
    275 		{
    276 		char buf[BUFSIZ];
    277 		register char *b_end, *bp;
    278 		register int c;
    279 
    280 		/*
    281 		 * Loop invariants:
    282 		 *	There is always room for one more character in record.
    283 		 *	R_end always points just past end of record.
    284 		 *	Rp always points just past last character in record.
    285 		 *	B_end always points just past last character in buf.
    286 		 *	Bp always points at next character in buf.
    287 		 */
    288 		b_end = buf;
    289 		bp = buf;
    290 		for (;;) {
    291 
    292 			/*
    293 			 * Read in a line implementing (\, newline)
    294 			 * line continuation.
    295 			 */
    296 			rp = record;
    297 			for (;;) {
    298 				if (bp >= b_end) {
    299 					int n;
    300 
    301 					n = read(fd, buf, sizeof(buf));
    302 					if (n <= 0) {
    303 						if (myfd)
    304 							(void)close(fd);
    305 						if (n < 0) {
    306 							free(record);
    307 							return (-2);
    308 						} else {
    309 							fd = -1;
    310 							eof = 1;
    311 							break;
    312 						}
    313 					}
    314 					b_end = buf+n;
    315 					bp = buf;
    316 				}
    317 
    318 				c = *bp++;
    319 				if (c == '\n') {
    320 					if (rp > record && *(rp-1) == '\\') {
    321 						rp--;
    322 						continue;
    323 					} else
    324 						break;
    325 				}
    326 				*rp++ = c;
    327 
    328 				/*
    329 				 * Enforce loop invariant: if no room
    330 				 * left in record buffer, try to get
    331 				 * some more.
    332 				 */
    333 				if (rp >= r_end) {
    334 					u_int pos;
    335 					size_t newsize;
    336 
    337 					pos = rp - record;
    338 					newsize = r_end - record + BFRAG;
    339 					record = realloc(record, newsize);
    340 					if (record == NULL) {
    341 						errno = ENOMEM;
    342 						if (myfd)
    343 							(void)close(fd);
    344 						return (-2);
    345 					}
    346 					r_end = record + newsize;
    347 					rp = record + pos;
    348 				}
    349 			}
    350 				/* loop invariant let's us do this */
    351 			*rp++ = '\0';
    352 
    353 			/*
    354 			 * If encountered eof check next file.
    355 			 */
    356 			if (eof)
    357 				break;
    358 
    359 			/*
    360 			 * Toss blank lines and comments.
    361 			 */
    362 			if (*record == '\0' || *record == '#')
    363 				continue;
    364 
    365 			/*
    366 			 * See if this is the record we want ...
    367 			 */
    368 			if (cgetmatch(record, name) == 0) {
    369 				if (nfield == NULL || !nfcmp(nfield, record)) {
    370 					foundit = 1;
    371 					break;	/* found it! */
    372 				}
    373 			}
    374 		}
    375 	}
    376 		if (foundit)
    377 			break;
    378 	}
    379 
    380 	if (!foundit)
    381 		return (-1);
    382 
    383 	/*
    384 	 * Got the capability record, but now we have to expand all tc=name
    385 	 * references in it ...
    386 	 */
    387 tc_exp:	{
    388 		register char *newicap, *s;
    389 		register int newilen;
    390 		u_int ilen;
    391 		int diff, iret, tclen;
    392 		char *icap, *scan, *tc, *tcstart, *tcend;
    393 
    394 		/*
    395 		 * Loop invariants:
    396 		 *	There is room for one more character in record.
    397 		 *	R_end points just past end of record.
    398 		 *	Rp points just past last character in record.
    399 		 *	Scan points at remainder of record that needs to be
    400 		 *	scanned for tc=name constructs.
    401 		 */
    402 		scan = record;
    403 		tc_not_resolved = 0;
    404 		for (;;) {
    405 			if ((tc = cgetcap(scan, "tc", '=')) == NULL)
    406 				break;
    407 
    408 			/*
    409 			 * Find end of tc=name and stomp on the trailing `:'
    410 			 * (if present) so we can use it to call ourselves.
    411 			 */
    412 			s = tc;
    413 			for (;;)
    414 				if (*s == '\0')
    415 					break;
    416 				else
    417 					if (*s++ == ':') {
    418 						*(s - 1) = '\0';
    419 						break;
    420 					}
    421 			tcstart = tc - 3;
    422 			tclen = s - tcstart;
    423 			tcend = s;
    424 
    425 			iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
    426 				      NULL);
    427 			newicap = icap;		/* Put into a register. */
    428 			newilen = ilen;
    429 			if (iret != 0) {
    430 				/* an error */
    431 				if (iret < -1) {
    432 					if (myfd)
    433 						(void)close(fd);
    434 					free(record);
    435 					return (iret);
    436 				}
    437 				if (iret == 1)
    438 					tc_not_resolved = 1;
    439 				/* couldn't resolve tc */
    440 				if (iret == -1) {
    441 					*(s - 1) = ':';
    442 					scan = s - 1;
    443 					tc_not_resolved = 1;
    444 					continue;
    445 
    446 				}
    447 			}
    448 			/* not interested in name field of tc'ed record */
    449 			s = newicap;
    450 			for (;;)
    451 				if (*s == '\0')
    452 					break;
    453 				else
    454 					if (*s++ == ':')
    455 						break;
    456 			newilen -= s - newicap;
    457 			newicap = s;
    458 
    459 			/* make sure interpolated record is `:'-terminated */
    460 			s += newilen;
    461 			if (*(s-1) != ':') {
    462 				*s = ':';	/* overwrite NUL with : */
    463 				newilen++;
    464 			}
    465 
    466 			/*
    467 			 * Make sure there's enough room to insert the
    468 			 * new record.
    469 			 */
    470 			diff = newilen - tclen;
    471 			if (diff >= r_end - rp) {
    472 				u_int pos, tcpos, tcposend;
    473 				size_t newsize;
    474 
    475 				pos = rp - record;
    476 				newsize = r_end - record + diff + BFRAG;
    477 				tcpos = tcstart - record;
    478 				tcposend = tcend - record;
    479 				record = realloc(record, newsize);
    480 				if (record == NULL) {
    481 					errno = ENOMEM;
    482 					if (myfd)
    483 						(void)close(fd);
    484 					free(icap);
    485 					return (-2);
    486 				}
    487 				r_end = record + newsize;
    488 				rp = record + pos;
    489 				tcstart = record + tcpos;
    490 				tcend = record + tcposend;
    491 			}
    492 
    493 			/*
    494 			 * Insert tc'ed record into our record.
    495 			 */
    496 			s = tcstart + newilen;
    497 			bcopy(tcend, s, rp - tcend);
    498 			bcopy(newicap, tcstart, newilen);
    499 			rp += diff;
    500 			free(icap);
    501 
    502 			/*
    503 			 * Start scan on `:' so next cgetcap works properly
    504 			 * (cgetcap always skips first field).
    505 			 */
    506 			scan = s-1;
    507 		}
    508 
    509 	}
    510 	/*
    511 	 * Close file (if we opened it), give back any extra memory, and
    512 	 * return capability, length and success.
    513 	 */
    514 	if (myfd)
    515 		(void)close(fd);
    516 	*len = rp - record - 1;	/* don't count NUL */
    517 	if (r_end > rp)
    518 		if ((record =
    519 		     realloc(record, (size_t)(rp - record))) == NULL) {
    520 			errno = ENOMEM;
    521 			return (-2);
    522 		}
    523 
    524 	*cap = record;
    525 	if (tc_not_resolved)
    526 		return (1);
    527 	return (0);
    528 }
    529 
    530 static int
    531 cdbget(capdbp, bp, name)
    532 	DB *capdbp;
    533 	char **bp, *name;
    534 {
    535 	DBT key, data;
    536 	char *buf;
    537 	int st;
    538 
    539 	key.data = name;
    540 	key.size = strlen(name);
    541 
    542 	for (;;) {
    543 		/* Get the reference. */
    544 		switch(capdbp->get(capdbp, &key, &data, 0)) {
    545 		case -1:
    546 			return (-2);
    547 		case 1:
    548 			return (-1);
    549 		}
    550 
    551 		/* If not an index to another record, leave. */
    552 		if (((char *)data.data)[0] != SHADOW)
    553 			break;
    554 
    555 		key.data = (char *)data.data + 1;
    556 		key.size = data.size - 1;
    557 	}
    558 
    559 	*bp = (char *)data.data + 1;
    560 	return (((char *)(data.data))[0] == TCERR ? 1 : 0);
    561 }
    562 
    563 /*
    564  * Cgetmatch will return 0 if name is one of the names of the capability
    565  * record buf, -1 if not.
    566  */
    567 int
    568 cgetmatch(buf, name)
    569 	char *buf, *name;
    570 {
    571 	register 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(buf, db_array)
    611 	char **buf, **db_array;
    612 {
    613 	(void)cgetclose();
    614 	return (cgetnext(buf, db_array));
    615 }
    616 
    617 static FILE *pfp;
    618 static int slash;
    619 static char **dbp;
    620 
    621 int
    622 cgetclose()
    623 {
    624 	if (pfp != NULL) {
    625 		(void)fclose(pfp);
    626 		pfp = NULL;
    627 	}
    628 	dbp = NULL;
    629 	gottoprec = 0;
    630 	slash = 0;
    631 	return(0);
    632 }
    633 
    634 /*
    635  * Cgetnext() gets either the first or next entry in the logical database
    636  * specified by db_array.  It returns 0 upon completion of the database, 1
    637  * upon returning an entry with more remaining, and -1 if an error occurs.
    638  */
    639 int
    640 cgetnext(bp, db_array)
    641         register char **bp;
    642 	char **db_array;
    643 {
    644 	size_t len;
    645 	int status, i, done;
    646 	char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
    647 	u_int dummy;
    648 
    649 	if (dbp == NULL)
    650 		dbp = db_array;
    651 
    652 	if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
    653 		(void)cgetclose();
    654 		return (-1);
    655 	}
    656 	for(;;) {
    657 		if (toprec && !gottoprec) {
    658 			gottoprec = 1;
    659 			line = toprec;
    660 		} else {
    661 			line = fgetline(pfp, &len);
    662 			if (line == NULL && pfp) {
    663 				(void)fclose(pfp);
    664 				if (ferror(pfp)) {
    665 					(void)cgetclose();
    666 					return (-1);
    667 				} else {
    668 					if (*++dbp == NULL) {
    669 						(void)cgetclose();
    670 						return (0);
    671 					} else if ((pfp =
    672 					    fopen(*dbp, "r")) == NULL) {
    673 						(void)cgetclose();
    674 						return (-1);
    675 					} else
    676 						continue;
    677 				}
    678 			}
    679 			if (len == 0) {
    680 				slash = 0;
    681 				continue;
    682 			}
    683 			if (isspace(*line) ||
    684 			    *line == ':' || *line == '#' || slash) {
    685 				if (line[len - 1] == '\\')
    686 					slash = 1;
    687 				else
    688 					slash = 0;
    689 				continue;
    690 			}
    691 			if (line[len - 1] == '\\')
    692 				slash = 1;
    693 			else
    694 				slash = 0;
    695 		}
    696 
    697 
    698 		/*
    699 		 * Line points to a name line.
    700 		 */
    701 		i = 0;
    702 		done = 0;
    703 		np = nbuf;
    704 		for (;;) {
    705 			for (cp = line; *cp != '\0'; cp++) {
    706 				if (*cp == ':') {
    707 					*np++ = ':';
    708 					done = 1;
    709 					break;
    710 				}
    711 				if (*cp == '\\')
    712 					break;
    713 				*np++ = *cp;
    714 			}
    715 			if (done) {
    716 				*np = '\0';
    717 				break;
    718 			} else { /* name field extends beyond the line */
    719 				line = fgetline(pfp, &len);
    720 				if (line == NULL && pfp) {
    721 					(void)fclose(pfp);
    722 					if (ferror(pfp)) {
    723 						(void)cgetclose();
    724 						return (-1);
    725 					}
    726 				}
    727 			}
    728 		}
    729 		rp = buf;
    730 		for(cp = nbuf; *cp != NULL; cp++)
    731 			if (*cp == '|' || *cp == ':')
    732 				break;
    733 			else
    734 				*rp++ = *cp;
    735 
    736 		*rp = '\0';
    737 		/*
    738 		 * XXX
    739 		 * Last argument of getent here should be nbuf if we want true
    740 		 * sequential access in the case of duplicates.
    741 		 * With NULL, getent will return the first entry found
    742 		 * rather than the duplicate entry record.  This is a
    743 		 * matter of semantics that should be resolved.
    744 		 */
    745 		status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
    746 		if (status == -2 || status == -3)
    747 			(void)cgetclose();
    748 
    749 		return (status + 1);
    750 	}
    751 	/* NOTREACHED */
    752 }
    753 
    754 /*
    755  * Cgetstr retrieves the value of the string capability cap from the
    756  * capability record pointed to by buf.  A pointer to a decoded, NUL
    757  * terminated, malloc'd copy of the string is returned in the char *
    758  * pointed to by str.  The length of the string not including the trailing
    759  * NUL is returned on success, -1 if the requested string capability
    760  * couldn't be found, -2 if a system error was encountered (storage
    761  * allocation failure).
    762  */
    763 int
    764 cgetstr(buf, cap, str)
    765 	char *buf, *cap;
    766 	char **str;
    767 {
    768 	register u_int m_room;
    769 	register char *bp, *mp;
    770 	int len;
    771 	char *mem;
    772 
    773 	/*
    774 	 * Find string capability cap
    775 	 */
    776 	bp = cgetcap(buf, cap, '=');
    777 	if (bp == NULL)
    778 		return (-1);
    779 
    780 	/*
    781 	 * Conversion / storage allocation loop ...  Allocate memory in
    782 	 * chunks SFRAG in size.
    783 	 */
    784 	if ((mem = malloc(SFRAG)) == NULL) {
    785 		errno = ENOMEM;
    786 		return (-2);	/* couldn't even allocate the first fragment */
    787 	}
    788 	m_room = SFRAG;
    789 	mp = mem;
    790 
    791 	while (*bp != ':' && *bp != '\0') {
    792 		/*
    793 		 * Loop invariants:
    794 		 *	There is always room for one more character in mem.
    795 		 *	Mp always points just past last character in mem.
    796 		 *	Bp always points at next character in buf.
    797 		 */
    798 		if (*bp == '^') {
    799 			bp++;
    800 			if (*bp == ':' || *bp == '\0')
    801 				break;	/* drop unfinished escape */
    802 			*mp++ = *bp++ & 037;
    803 		} else if (*bp == '\\') {
    804 			bp++;
    805 			if (*bp == ':' || *bp == '\0')
    806 				break;	/* drop unfinished escape */
    807 			if ('0' <= *bp && *bp <= '7') {
    808 				register int n, i;
    809 
    810 				n = 0;
    811 				i = 3;	/* maximum of three octal digits */
    812 				do {
    813 					n = n * 8 + (*bp++ - '0');
    814 				} while (--i && '0' <= *bp && *bp <= '7');
    815 				*mp++ = n;
    816 			}
    817 			else switch (*bp++) {
    818 				case 'b': case 'B':
    819 					*mp++ = '\b';
    820 					break;
    821 				case 't': case 'T':
    822 					*mp++ = '\t';
    823 					break;
    824 				case 'n': case 'N':
    825 					*mp++ = '\n';
    826 					break;
    827 				case 'f': case 'F':
    828 					*mp++ = '\f';
    829 					break;
    830 				case 'r': case 'R':
    831 					*mp++ = '\r';
    832 					break;
    833 				case 'e': case 'E':
    834 					*mp++ = ESC;
    835 					break;
    836 				case 'c': case 'C':
    837 					*mp++ = ':';
    838 					break;
    839 				default:
    840 					/*
    841 					 * Catches '\', '^', and
    842 					 *  everything else.
    843 					 */
    844 					*mp++ = *(bp-1);
    845 					break;
    846 			}
    847 		} else
    848 			*mp++ = *bp++;
    849 		m_room--;
    850 
    851 		/*
    852 		 * Enforce loop invariant: if no room left in current
    853 		 * buffer, try to get some more.
    854 		 */
    855 		if (m_room == 0) {
    856 			size_t size = mp - mem;
    857 
    858 			if ((mem = realloc(mem, size + SFRAG)) == NULL)
    859 				return (-2);
    860 			m_room = SFRAG;
    861 			mp = mem + size;
    862 		}
    863 	}
    864 	*mp++ = '\0';	/* loop invariant let's us do this */
    865 	m_room--;
    866 	len = mp - mem - 1;
    867 
    868 	/*
    869 	 * Give back any extra memory and return value and success.
    870 	 */
    871 	if (m_room != 0)
    872 		if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
    873 			return (-2);
    874 	*str = mem;
    875 	return (len);
    876 }
    877 
    878 /*
    879  * Cgetustr retrieves the value of the string capability cap from the
    880  * capability record pointed to by buf.  The difference between cgetustr()
    881  * and cgetstr() is that cgetustr does not decode escapes but rather treats
    882  * all characters literally.  A pointer to a  NUL terminated malloc'd
    883  * copy of the string is returned in the char pointed to by str.  The
    884  * length of the string not including the trailing NUL is returned on success,
    885  * -1 if the requested string capability couldn't be found, -2 if a system
    886  * error was encountered (storage allocation failure).
    887  */
    888 int
    889 cgetustr(buf, cap, str)
    890 	char *buf, *cap, **str;
    891 {
    892 	register u_int m_room;
    893 	register char *bp, *mp;
    894 	int len;
    895 	char *mem;
    896 
    897 	/*
    898 	 * Find string capability cap
    899 	 */
    900 	if ((bp = cgetcap(buf, cap, '=')) == NULL)
    901 		return (-1);
    902 
    903 	/*
    904 	 * Conversion / storage allocation loop ...  Allocate memory in
    905 	 * chunks SFRAG in size.
    906 	 */
    907 	if ((mem = malloc(SFRAG)) == NULL) {
    908 		errno = ENOMEM;
    909 		return (-2);	/* couldn't even allocate the first fragment */
    910 	}
    911 	m_room = SFRAG;
    912 	mp = mem;
    913 
    914 	while (*bp != ':' && *bp != '\0') {
    915 		/*
    916 		 * Loop invariants:
    917 		 *	There is always room for one more character in mem.
    918 		 *	Mp always points just past last character in mem.
    919 		 *	Bp always points at next character in buf.
    920 		 */
    921 		*mp++ = *bp++;
    922 		m_room--;
    923 
    924 		/*
    925 		 * Enforce loop invariant: if no room left in current
    926 		 * buffer, try to get some more.
    927 		 */
    928 		if (m_room == 0) {
    929 			size_t size = mp - mem;
    930 
    931 			if ((mem = realloc(mem, size + SFRAG)) == NULL)
    932 				return (-2);
    933 			m_room = SFRAG;
    934 			mp = mem + size;
    935 		}
    936 	}
    937 	*mp++ = '\0';	/* loop invariant let's us do this */
    938 	m_room--;
    939 	len = mp - mem - 1;
    940 
    941 	/*
    942 	 * Give back any extra memory and return value and success.
    943 	 */
    944 	if (m_room != 0)
    945 		if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
    946 			return (-2);
    947 	*str = mem;
    948 	return (len);
    949 }
    950 
    951 /*
    952  * Cgetnum retrieves the value of the numeric capability cap from the
    953  * capability record pointed to by buf.  The numeric value is returned in
    954  * the long pointed to by num.  0 is returned on success, -1 if the requested
    955  * numeric capability couldn't be found.
    956  */
    957 int
    958 cgetnum(buf, cap, num)
    959 	char *buf, *cap;
    960 	long *num;
    961 {
    962 	register long n;
    963 	register int base, digit;
    964 	register char *bp;
    965 
    966 	/*
    967 	 * Find numeric capability cap
    968 	 */
    969 	bp = cgetcap(buf, cap, '#');
    970 	if (bp == NULL)
    971 		return (-1);
    972 
    973 	/*
    974 	 * Look at value and determine numeric base:
    975 	 *	0x... or 0X...	hexadecimal,
    976 	 * else	0...		octal,
    977 	 * else			decimal.
    978 	 */
    979 	if (*bp == '0') {
    980 		bp++;
    981 		if (*bp == 'x' || *bp == 'X') {
    982 			bp++;
    983 			base = 16;
    984 		} else
    985 			base = 8;
    986 	} else
    987 		base = 10;
    988 
    989 	/*
    990 	 * Conversion loop ...
    991 	 */
    992 	n = 0;
    993 	for (;;) {
    994 		if ('0' <= *bp && *bp <= '9')
    995 			digit = *bp - '0';
    996 		else if ('a' <= *bp && *bp <= 'f')
    997 			digit = 10 + *bp - 'a';
    998 		else if ('A' <= *bp && *bp <= 'F')
    999 			digit = 10 + *bp - 'A';
   1000 		else
   1001 			break;
   1002 
   1003 		if (digit >= base)
   1004 			break;
   1005 
   1006 		n = n * base + digit;
   1007 		bp++;
   1008 	}
   1009 
   1010 	/*
   1011 	 * Return value and success.
   1012 	 */
   1013 	*num = n;
   1014 	return (0);
   1015 }
   1016 
   1017 
   1018 /*
   1019  * Compare name field of record.
   1020  */
   1021 static int
   1022 nfcmp(nf, rec)
   1023 	char *nf, *rec;
   1024 {
   1025 	char *cp, tmp;
   1026 	int ret;
   1027 
   1028 	for (cp = rec; *cp != ':'; cp++)
   1029 		;
   1030 
   1031 	tmp = *(cp + 1);
   1032 	*(cp + 1) = '\0';
   1033 	ret = strcmp(nf, rec);
   1034 	*(cp + 1) = tmp;
   1035 
   1036 	return (ret);
   1037 }
   1038