1/*	$NetBSD: getcap.c,v 1.29 1999/03/29 09:27:29 abs Exp $	*/
2
3/*-
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Casey Leedom of Lawrence Livermore National Laboratory.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <config.h>
36
37#include "roken.h"
38
39#include <sys/types.h>
40#include <ctype.h>
41#if defined(HAVE_DB_185_H)
42#include <db_185.h>
43#elif defined(HAVE_DB_H)
44#include <db.h>
45#endif
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#if 0
56#define	BSIZE		1024
57#endif
58#define	ESC		('[' & 037)	/* ASCII ESC */
59#define	MAX_RECURSION	32		/* maximum getent recursion */
60#define	SFRAG		100		/* cgetstr mallocs in SFRAG chunks */
61
62#define RECOK	(char)0
63#define TCERR	(char)1
64#define	SHADOW	(char)2
65
66static size_t	 topreclen;	/* toprec length */
67static char	*toprec;	/* Additional record specified by cgetset() */
68static int	 gottoprec;	/* Flag indicating retrieval of toprecord */
69
70#if 0 /*
71       * Don't use db support unless it's build into libc but we don't
72       * check for that now, so just disable the code.
73       */
74#if defined(HAVE_DBOPEN) && defined(HAVE_DB_H)
75#define USE_DB
76#endif
77#endif
78
79#ifdef USE_DB
80static int	cdbget (DB *, char **, const char *);
81#endif
82static int 	getent (char **, size_t *, char **, int, const char *, int, char *);
83static int	nfcmp (char *, char *);
84
85
86ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetset(const char *ent);
87ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL cgetcap(char *buf, const char *cap, int type);
88ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetent(char **buf, char **db_array, const char *name);
89ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetmatch(const char *buf, const char *name);
90ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetclose(void);
91#if 0
92int cgetfirst(char **buf, char **db_array);
93int cgetnext(char **bp, char **db_array);
94#endif
95ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetstr(char *buf, const char *cap, char **str);
96ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetustr(char *buf, const char *cap, char **str);
97ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetnum(char *buf, const char *cap, long *num);
98/*
99 * Cgetset() allows the addition of a user specified buffer to be added
100 * to the database array, in effect "pushing" the buffer on top of the
101 * virtual database. 0 is returned on success, -1 on failure.
102 */
103ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
104cgetset(const char *ent)
105{
106    const char *source, *check;
107    char *dest;
108
109    if (ent == NULL) {
110	if (toprec)
111	    free(toprec);
112	toprec = NULL;
113	topreclen = 0;
114	return (0);
115    }
116    topreclen = strlen(ent);
117    if ((toprec = malloc (topreclen + 1)) == NULL) {
118	errno = ENOMEM;
119	return (-1);
120    }
121    gottoprec = 0;
122
123    source=ent;
124    dest=toprec;
125    while (*source) { /* Strip whitespace */
126	*dest++ = *source++; /* Do not check first field */
127	while (*source == ':') {
128	    check=source+1;
129	    while (*check && (isspace((unsigned char)*check) ||
130			      (*check=='\\' && isspace((unsigned char)check[1]))))
131		++check;
132	    if( *check == ':' )
133		source=check;
134	    else
135		break;
136
137	}
138    }
139    *dest=0;
140
141    return (0);
142}
143
144/*
145 * Cgetcap searches the capability record buf for the capability cap with
146 * type `type'.  A pointer to the value of cap is returned on success, NULL
147 * if the requested capability couldn't be found.
148 *
149 * Specifying a type of ':' means that nothing should follow cap (:cap:).
150 * In this case a pointer to the terminating ':' or NUL will be returned if
151 * cap is found.
152 *
153 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
154 * return NULL.
155 */
156ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
157cgetcap(char *buf, const char *cap, int type)
158{
159    char *bp;
160    const char *cp;
161
162    bp = buf;
163    for (;;) {
164	/*
165	 * Skip past the current capability field - it's either the
166	 * name field if this is the first time through the loop, or
167	 * the remainder of a field whose name failed to match cap.
168	 */
169	for (;;)
170	    if (*bp == '\0')
171		return (NULL);
172	    else
173		if (*bp++ == ':')
174		    break;
175
176	/*
177	 * Try to match (cap, type) in buf.
178	 */
179	for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
180	    continue;
181	if (*cp != '\0')
182	    continue;
183	if (*bp == '@')
184	    return (NULL);
185	if (type == ':') {
186	    if (*bp != '\0' && *bp != ':')
187		continue;
188	    return(bp);
189	}
190	if (*bp != type)
191	    continue;
192	bp++;
193	return (*bp == '@' ? NULL : bp);
194    }
195    /* NOTREACHED */
196}
197
198/*
199 * Cgetent extracts the capability record name from the NULL terminated file
200 * array db_array and returns a pointer to a malloc'd copy of it in buf.
201 * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
202 * cgetflag, and cgetstr, but may then be free'd.  0 is returned on success,
203 * -1 if the requested record couldn't be found, -2 if a system error was
204 * encountered (couldn't open/read a file, etc.), and -3 if a potential
205 * reference loop is detected.
206 */
207ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
208cgetent(char **buf, char **db_array, const char *name)
209{
210    size_t dummy;
211
212    return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
213}
214
215/*
216 * Getent implements the functions of cgetent.  If fd is non-negative,
217 * *db_array has already been opened and fd is the open file descriptor.  We
218 * do this to save time and avoid using up file descriptors for tc=
219 * recursions.
220 *
221 * Getent returns the same success/failure codes as cgetent.  On success, a
222 * pointer to a malloc'ed capability record with all tc= capabilities fully
223 * expanded and its length (not including trailing ASCII NUL) are left in
224 * *cap and *len.
225 *
226 * Basic algorithm:
227 *	+ Allocate memory incrementally as needed in chunks of size BFRAG
228 *	  for capability buffer.
229 *	+ Recurse for each tc=name and interpolate result.  Stop when all
230 *	  names interpolated, a name can't be found, or depth exceeds
231 *	  MAX_RECURSION.
232 */
233static int
234getent(char **cap, size_t *len, char **db_array, int fd,
235       const char *name, int depth, char *nfield)
236{
237    char *r_end, *rp = NULL, **db_p;	/* pacify gcc */
238    int myfd = 0, eof, foundit;
239    char *record;
240    int tc_not_resolved;
241
242    /*
243     * Return with ``loop detected'' error if we've recursed more than
244     * MAX_RECURSION times.
245     */
246    if (depth > MAX_RECURSION)
247	return (-3);
248
249    /*
250     * Check if we have a top record from cgetset().
251     */
252    if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
253	size_t len = topreclen + BFRAG;
254	if ((record = malloc (len)) == NULL) {
255	    errno = ENOMEM;
256	    return (-2);
257	}
258	(void)strlcpy(record, toprec, len);
259	db_p = db_array;
260	rp = record + topreclen + 1;
261	r_end = rp + BFRAG;
262	goto tc_exp;
263    }
264    /*
265     * Allocate first chunk of memory.
266     */
267    if ((record = malloc(BFRAG)) == NULL) {
268	errno = ENOMEM;
269	return (-2);
270    }
271    r_end = record + BFRAG;
272    foundit = 0;
273    /*
274     * Loop through database array until finding the record.
275     */
276
277    for (db_p = db_array; *db_p != NULL; db_p++) {
278	eof = 0;
279
280	/*
281	 * Open database if not already open.
282	 */
283
284	if (fd >= 0) {
285	    (void)lseek(fd, (off_t)0, SEEK_SET);
286	} else {
287#ifdef USE_DB
288	    char pbuf[_POSIX_PATH_MAX];
289	    char *cbuf;
290	    size_t clen;
291	    int retval;
292	    DB *capdbp;
293
294	    (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
295	    if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
296		!= NULL) {
297		free(record);
298		retval = cdbget(capdbp, &record, name);
299		if (retval < 0) {
300		    /* no record available */
301		    (void)capdbp->close(capdbp);
302		    return (retval);
303		}
304				/* save the data; close frees it */
305		clen = strlen(record);
306		cbuf = malloc(clen + 1);
307		if (cbuf == NULL)
308		    return (-2);
309		memmove(cbuf, record, clen + 1);
310		if (capdbp->close(capdbp) < 0) {
311		    free(cbuf);
312		    return (-2);
313		}
314		*len = clen;
315		*cap = cbuf;
316		return (retval);
317	    } else
318#endif
319	    {
320		fd = open(*db_p, O_RDONLY, 0);
321		if (fd < 0) {
322		    /* No error on unfound file. */
323		    continue;
324		}
325		myfd = 1;
326	    }
327	}
328	/*
329	 * Find the requested capability record ...
330	 */
331	{
332	    char buf[BUFSIZ];
333	    char *b_end, *bp, *cp;
334	    int c, slash;
335
336	    /*
337	     * Loop invariants:
338	     *	There is always room for one more character in record.
339	     *	R_end always points just past end of record.
340	     *	Rp always points just past last character in record.
341	     *	B_end always points just past last character in buf.
342	     *	Bp always points at next character in buf.
343	     *	Cp remembers where the last colon was.
344	     */
345	    b_end = buf;
346	    bp = buf;
347	    cp = 0;
348	    slash = 0;
349	    for (;;) {
350
351		/*
352		 * Read in a line implementing (\, newline)
353		 * line continuation.
354		 */
355		rp = record;
356		for (;;) {
357		    if (bp >= b_end) {
358			int n;
359
360			n = read(fd, buf, sizeof(buf));
361			if (n <= 0) {
362			    if (myfd)
363				(void)close(fd);
364			    if (n < 0) {
365				free(record);
366				return (-2);
367			    } else {
368				fd = -1;
369				eof = 1;
370				break;
371			    }
372			}
373			b_end = buf+n;
374			bp = buf;
375		    }
376
377		    c = *bp++;
378		    if (c == '\n') {
379			if (slash) {
380			    slash = 0;
381			    rp--;
382			    continue;
383			} else
384			    break;
385		    }
386		    if (slash) {
387			slash = 0;
388			cp = 0;
389		    }
390		    if (c == ':') {
391			/*
392			 * If the field was `empty' (i.e.
393			 * contained only white space), back up
394			 * to the colon (eliminating the
395			 * field).
396			 */
397			if (cp)
398			    rp = cp;
399			else
400			    cp = rp;
401		    } else if (c == '\\') {
402			slash = 1;
403		    } else if (c != ' ' && c != '\t') {
404			/*
405			 * Forget where the colon was, as this
406			 * is not an empty field.
407			 */
408			cp = 0;
409		    }
410		    *rp++ = c;
411
412				/*
413				 * Enforce loop invariant: if no room
414				 * left in record buffer, try to get
415				 * some more.
416				 */
417		    if (rp >= r_end) {
418			u_int pos;
419			size_t newsize;
420
421			pos = rp - record;
422			newsize = r_end - record + BFRAG;
423			record = realloc(record, newsize);
424			if (record == NULL) {
425			    errno = ENOMEM;
426			    if (myfd)
427				(void)close(fd);
428			    return (-2);
429			}
430			r_end = record + newsize;
431			rp = record + pos;
432		    }
433		}
434		/* Eliminate any white space after the last colon. */
435		if (cp)
436		    rp = cp + 1;
437		/* Loop invariant lets us do this. */
438		*rp++ = '\0';
439
440		/*
441		 * If encountered eof check next file.
442		 */
443		if (eof)
444		    break;
445
446		/*
447		 * Toss blank lines and comments.
448		 */
449		if (*record == '\0' || *record == '#')
450		    continue;
451
452		/*
453		 * See if this is the record we want ...
454		 */
455		if (cgetmatch(record, name) == 0) {
456		    if (nfield == NULL || !nfcmp(nfield, record)) {
457			foundit = 1;
458			break;	/* found it! */
459		    }
460		}
461	    }
462	}
463	if (foundit)
464	    break;
465    }
466
467    if (!foundit)
468	return (-1);
469
470    /*
471     * Got the capability record, but now we have to expand all tc=name
472     * references in it ...
473     */
474 tc_exp:	{
475	char *newicap, *s;
476	size_t ilen, newilen;
477	int diff, iret, tclen;
478	char *icap, *scan, *tc, *tcstart, *tcend;
479
480	/*
481	 * Loop invariants:
482	 *	There is room for one more character in record.
483	 *	R_end points just past end of record.
484	 *	Rp points just past last character in record.
485	 *	Scan points at remainder of record that needs to be
486	 *	scanned for tc=name constructs.
487	 */
488	scan = record;
489	tc_not_resolved = 0;
490	for (;;) {
491	    if ((tc = cgetcap(scan, "tc", '=')) == NULL)
492		break;
493
494	    /*
495	     * Find end of tc=name and stomp on the trailing `:'
496	     * (if present) so we can use it to call ourselves.
497	     */
498	    s = tc;
499	    for (;;)
500		if (*s == '\0')
501		    break;
502		else
503		    if (*s++ == ':') {
504			*(s - 1) = '\0';
505			break;
506		    }
507	    tcstart = tc - 3;
508	    tclen = s - tcstart;
509	    tcend = s;
510
511	    iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
512			  NULL);
513	    newicap = icap;		/* Put into a register. */
514	    newilen = ilen;
515	    if (iret != 0) {
516				/* an error */
517		if (iret < -1) {
518		    if (myfd)
519			(void)close(fd);
520		    free(record);
521		    return (iret);
522		}
523		if (iret == 1)
524		    tc_not_resolved = 1;
525				/* couldn't resolve tc */
526		if (iret == -1) {
527		    *(s - 1) = ':';
528		    scan = s - 1;
529		    tc_not_resolved = 1;
530		    continue;
531
532		}
533	    }
534	    /* not interested in name field of tc'ed record */
535	    s = newicap;
536	    for (;;)
537		if (*s == '\0')
538		    break;
539		else
540		    if (*s++ == ':')
541			break;
542	    newilen -= s - newicap;
543	    newicap = s;
544
545	    /* make sure interpolated record is `:'-terminated */
546	    s += newilen;
547	    if (*(s-1) != ':') {
548		*s = ':';	/* overwrite NUL with : */
549		newilen++;
550	    }
551
552	    /*
553	     * Make sure there's enough room to insert the
554	     * new record.
555	     */
556	    diff = newilen - tclen;
557	    if (diff >= r_end - rp) {
558		u_int pos, tcpos, tcposend;
559		size_t newsize;
560
561		pos = rp - record;
562		newsize = r_end - record + diff + BFRAG;
563		tcpos = tcstart - record;
564		tcposend = tcend - record;
565		record = realloc(record, newsize);
566		if (record == NULL) {
567		    errno = ENOMEM;
568		    if (myfd)
569			(void)close(fd);
570		    free(icap);
571		    return (-2);
572		}
573		r_end = record + newsize;
574		rp = record + pos;
575		tcstart = record + tcpos;
576		tcend = record + tcposend;
577	    }
578
579	    /*
580	     * Insert tc'ed record into our record.
581	     */
582	    s = tcstart + newilen;
583	    memmove(s, tcend,  (size_t)(rp - tcend));
584	    memmove(tcstart, newicap, newilen);
585	    rp += diff;
586	    free(icap);
587
588	    /*
589	     * Start scan on `:' so next cgetcap works properly
590	     * (cgetcap always skips first field).
591	     */
592	    scan = s-1;
593	}
594
595    }
596    /*
597     * Close file (if we opened it), give back any extra memory, and
598     * return capability, length and success.
599     */
600    if (myfd)
601	(void)close(fd);
602    *len = rp - record - 1;	/* don't count NUL */
603    if (r_end > rp)
604	if ((record =
605	     realloc(record, (size_t)(rp - record))) == NULL) {
606	    errno = ENOMEM;
607	    return (-2);
608	}
609
610    *cap = record;
611    if (tc_not_resolved)
612	return (1);
613    return (0);
614}
615
616#ifdef USE_DB
617static int
618cdbget(DB *capdbp, char **bp, const char *name)
619{
620	DBT key;
621	DBT data;
622
623	/* LINTED key is not modified */
624	key.data = (char *)name;
625	key.size = strlen(name);
626
627	for (;;) {
628		/* Get the reference. */
629		switch(capdbp->get(capdbp, &key, &data, 0)) {
630		case -1:
631			return (-2);
632		case 1:
633			return (-1);
634		}
635
636		/* If not an index to another record, leave. */
637		if (((char *)data.data)[0] != SHADOW)
638			break;
639
640		key.data = (char *)data.data + 1;
641		key.size = data.size - 1;
642	}
643
644	*bp = (char *)data.data + 1;
645	return (((char *)(data.data))[0] == TCERR ? 1 : 0);
646}
647#endif /* USE_DB */
648
649/*
650 * Cgetmatch will return 0 if name is one of the names of the capability
651 * record buf, -1 if not.
652 */
653int
654cgetmatch(const char *buf, const char *name)
655{
656    const char *np, *bp;
657
658    /*
659     * Start search at beginning of record.
660     */
661    bp = buf;
662    for (;;) {
663	/*
664	 * Try to match a record name.
665	 */
666	np = name;
667	for (;;)
668	    if (*np == '\0') {
669		if (*bp == '|' || *bp == ':' || *bp == '\0')
670		    return (0);
671		else
672		    break;
673	    } else
674		if (*bp++ != *np++)
675		    break;
676
677	/*
678	 * Match failed, skip to next name in record.
679	 */
680	bp--;	/* a '|' or ':' may have stopped the match */
681	for (;;)
682	    if (*bp == '\0' || *bp == ':')
683		return (-1);	/* match failed totally */
684	    else
685		if (*bp++ == '|')
686		    break;	/* found next name */
687    }
688}
689
690#if 0
691int
692cgetfirst(char **buf, char **db_array)
693{
694    (void)cgetclose();
695    return (cgetnext(buf, db_array));
696}
697#endif
698
699static FILE *pfp;
700static int slash;
701static char **dbp;
702
703ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
704cgetclose(void)
705{
706    if (pfp != NULL) {
707	(void)fclose(pfp);
708	pfp = NULL;
709    }
710    dbp = NULL;
711    gottoprec = 0;
712    slash = 0;
713    return(0);
714}
715
716#if 0
717/*
718 * Cgetnext() gets either the first or next entry in the logical database
719 * specified by db_array.  It returns 0 upon completion of the database, 1
720 * upon returning an entry with more remaining, and -1 if an error occurs.
721 */
722int
723cgetnext(char **bp, char **db_array)
724{
725    size_t len;
726    int status, done;
727    char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
728    size_t dummy;
729
730    if (dbp == NULL)
731	dbp = db_array;
732
733    if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
734	(void)cgetclose();
735	return (-1);
736    }
737    for(;;) {
738	if (toprec && !gottoprec) {
739	    gottoprec = 1;
740	    line = toprec;
741	} else {
742	    line = fgetln(pfp, &len);
743	    if (line == NULL && pfp) {
744		if (ferror(pfp)) {
745		    (void)cgetclose();
746		    return (-1);
747		} else {
748		    (void)fclose(pfp);
749		    pfp = NULL;
750		    if (*++dbp == NULL) {
751			(void)cgetclose();
752			return (0);
753		    } else if ((pfp =
754				fopen(*dbp, "r")) == NULL) {
755			(void)cgetclose();
756			return (-1);
757		    } else
758			continue;
759		}
760	    } else
761		line[len - 1] = '\0';
762	    if (len == 1) {
763		slash = 0;
764		continue;
765	    }
766	    if (isspace((unsigned char)*line) ||
767		*line == ':' || *line == '#' || slash) {
768		if (line[len - 2] == '\\')
769		    slash = 1;
770		else
771		    slash = 0;
772		continue;
773	    }
774	    if (line[len - 2] == '\\')
775		slash = 1;
776	    else
777		slash = 0;
778	}
779
780
781	/*
782	 * Line points to a name line.
783	 */
784	done = 0;
785	np = nbuf;
786	for (;;) {
787	    for (cp = line; *cp != '\0'; cp++) {
788		if (*cp == ':') {
789		    *np++ = ':';
790		    done = 1;
791		    break;
792		}
793		if (*cp == '\\')
794		    break;
795		*np++ = *cp;
796	    }
797	    if (done) {
798		*np = '\0';
799		break;
800	    } else { /* name field extends beyond the line */
801		line = fgetln(pfp, &len);
802		if (line == NULL && pfp) {
803		    if (ferror(pfp)) {
804			(void)cgetclose();
805			return (-1);
806		    }
807		    (void)fclose(pfp);
808		    pfp = NULL;
809		    *np = '\0';
810		    break;
811		} else
812		    line[len - 1] = '\0';
813	    }
814	}
815	rp = buf;
816	for(cp = nbuf; *cp != '\0'; cp++)
817	    if (*cp == '|' || *cp == ':')
818		break;
819	    else
820		*rp++ = *cp;
821
822	*rp = '\0';
823	/*
824	 * XXX
825	 * Last argument of getent here should be nbuf if we want true
826	 * sequential access in the case of duplicates.
827	 * With NULL, getent will return the first entry found
828	 * rather than the duplicate entry record.  This is a
829	 * matter of semantics that should be resolved.
830	 */
831	status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
832	if (status == -2 || status == -3)
833	    (void)cgetclose();
834
835	return (status + 1);
836    }
837    /* NOTREACHED */
838}
839#endif
840
841/*
842 * Cgetstr retrieves the value of the string capability cap from the
843 * capability record pointed to by buf.  A pointer to a decoded, NUL
844 * terminated, malloc'd copy of the string is returned in the char *
845 * pointed to by str.  The length of the string not including the trailing
846 * NUL is returned on success, -1 if the requested string capability
847 * couldn't be found, -2 if a system error was encountered (storage
848 * allocation failure).
849 */
850ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
851cgetstr(char *buf, const char *cap, char **str)
852{
853    u_int m_room;
854    const char *bp;
855    char *mp;
856    int len;
857    char *mem, *nmem;
858
859    *str = NULL;
860
861    /*
862     * Find string capability cap
863     */
864    bp = cgetcap(buf, cap, '=');
865    if (bp == NULL)
866	return (-1);
867
868    /*
869     * Conversion / storage allocation loop ...  Allocate memory in
870     * chunks SFRAG in size.
871     */
872    if ((mem = malloc(SFRAG)) == NULL) {
873	errno = ENOMEM;
874	return (-2);	/* couldn't even allocate the first fragment */
875    }
876    m_room = SFRAG;
877    mp = mem;
878
879    while (*bp != ':' && *bp != '\0') {
880	/*
881	 * Loop invariants:
882	 *	There is always room for one more character in mem.
883	 *	Mp always points just past last character in mem.
884	 *	Bp always points at next character in buf.
885	 */
886	if (*bp == '^') {
887	    bp++;
888	    if (*bp == ':' || *bp == '\0')
889		break;	/* drop unfinished escape */
890	    *mp++ = *bp++ & 037;
891	} else if (*bp == '\\') {
892	    bp++;
893	    if (*bp == ':' || *bp == '\0')
894		break;	/* drop unfinished escape */
895	    if ('0' <= *bp && *bp <= '7') {
896		int n, i;
897
898		n = 0;
899		i = 3;	/* maximum of three octal digits */
900		do {
901		    n = n * 8 + (*bp++ - '0');
902		} while (--i && '0' <= *bp && *bp <= '7');
903		*mp++ = n;
904	    }
905	    else switch (*bp++) {
906	    case 'b': case 'B':
907		*mp++ = '\b';
908		break;
909	    case 't': case 'T':
910		*mp++ = '\t';
911		break;
912	    case 'n': case 'N':
913		*mp++ = '\n';
914		break;
915	    case 'f': case 'F':
916		*mp++ = '\f';
917		break;
918	    case 'r': case 'R':
919		*mp++ = '\r';
920		break;
921	    case 'e': case 'E':
922		*mp++ = ESC;
923		break;
924	    case 'c': case 'C':
925		*mp++ = ':';
926		break;
927	    default:
928		/*
929		 * Catches '\', '^', and
930		 *  everything else.
931		 */
932		*mp++ = *(bp-1);
933		break;
934	    }
935	} else
936	    *mp++ = *bp++;
937	m_room--;
938
939	/*
940	 * Enforce loop invariant: if no room left in current
941	 * buffer, try to get some more.
942	 */
943	if (m_room == 0) {
944	    size_t size = mp - mem;
945
946	    if ((nmem = realloc(mem, size + SFRAG)) == NULL) {
947		free(mem);
948		return (-2);
949	    }
950	    mem = nmem;
951	    m_room = SFRAG;
952	    mp = mem + size;
953	}
954    }
955    *mp++ = '\0';	/* loop invariant let's us do this */
956    m_room--;
957    len = mp - mem - 1;
958
959    /*
960     * Give back any extra memory and return value and success.
961     */
962    if (m_room != 0) {
963	if ((nmem = realloc(mem, (size_t)(mp - mem))) == NULL) {
964	    free(mem);
965	    return (-2);
966	}
967	mem = nmem;
968    }
969    *str = mem;
970    return (len);
971}
972
973/*
974 * Cgetustr retrieves the value of the string capability cap from the
975 * capability record pointed to by buf.  The difference between cgetustr()
976 * and cgetstr() is that cgetustr does not decode escapes but rather treats
977 * all characters literally.  A pointer to a  NUL terminated malloc'd
978 * copy of the string is returned in the char pointed to by str.  The
979 * length of the string not including the trailing NUL is returned on success,
980 * -1 if the requested string capability couldn't be found, -2 if a system
981 * error was encountered (storage allocation failure).
982 */
983ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
984cgetustr(char *buf, const char *cap, char **str)
985{
986    u_int m_room;
987    const char *bp;
988    char *mp;
989    int len;
990    char *mem;
991
992    /*
993     * Find string capability cap
994     */
995    if ((bp = cgetcap(buf, cap, '=')) == NULL)
996	return (-1);
997
998    /*
999     * Conversion / storage allocation loop ...  Allocate memory in
1000     * chunks SFRAG in size.
1001     */
1002    if ((mem = malloc(SFRAG)) == NULL) {
1003	errno = ENOMEM;
1004	return (-2);	/* couldn't even allocate the first fragment */
1005    }
1006    m_room = SFRAG;
1007    mp = mem;
1008
1009    while (*bp != ':' && *bp != '\0') {
1010	/*
1011	 * Loop invariants:
1012	 *	There is always room for one more character in mem.
1013	 *	Mp always points just past last character in mem.
1014	 *	Bp always points at next character in buf.
1015	 */
1016	*mp++ = *bp++;
1017	m_room--;
1018
1019	/*
1020	 * Enforce loop invariant: if no room left in current
1021	 * buffer, try to get some more.
1022	 */
1023	if (m_room == 0) {
1024	    size_t size = mp - mem;
1025
1026	    if ((mem = realloc(mem, size + SFRAG)) == NULL)
1027		return (-2);
1028	    m_room = SFRAG;
1029	    mp = mem + size;
1030	}
1031    }
1032    *mp++ = '\0';	/* loop invariant let's us do this */
1033    m_room--;
1034    len = mp - mem - 1;
1035
1036    /*
1037     * Give back any extra memory and return value and success.
1038     */
1039    if (m_room != 0)
1040	if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
1041	    return (-2);
1042    *str = mem;
1043    return (len);
1044}
1045
1046/*
1047 * Cgetnum retrieves the value of the numeric capability cap from the
1048 * capability record pointed to by buf.  The numeric value is returned in
1049 * the long pointed to by num.  0 is returned on success, -1 if the requested
1050 * numeric capability couldn't be found.
1051 */
1052ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
1053cgetnum(char *buf, const char *cap, long *num)
1054{
1055    long n;
1056    int base, digit;
1057    const char *bp;
1058
1059    /*
1060     * Find numeric capability cap
1061     */
1062    bp = cgetcap(buf, cap, '#');
1063    if (bp == NULL)
1064	return (-1);
1065
1066    /*
1067     * Look at value and determine numeric base:
1068     *	0x... or 0X...	hexadecimal,
1069     * else	0...		octal,
1070     * else			decimal.
1071     */
1072    if (*bp == '0') {
1073	bp++;
1074	if (*bp == 'x' || *bp == 'X') {
1075	    bp++;
1076	    base = 16;
1077	} else
1078	    base = 8;
1079    } else
1080	base = 10;
1081
1082    /*
1083     * Conversion loop ...
1084     */
1085    n = 0;
1086    for (;;) {
1087	if ('0' <= *bp && *bp <= '9')
1088	    digit = *bp - '0';
1089	else if ('a' <= *bp && *bp <= 'f')
1090	    digit = 10 + *bp - 'a';
1091	else if ('A' <= *bp && *bp <= 'F')
1092	    digit = 10 + *bp - 'A';
1093	else
1094	    break;
1095
1096	if (digit >= base)
1097	    break;
1098
1099	n = n * base + digit;
1100	bp++;
1101    }
1102
1103    /*
1104     * Return value and success.
1105     */
1106    *num = n;
1107    return (0);
1108}
1109
1110
1111/*
1112 * Compare name field of record.
1113 */
1114static int
1115nfcmp(char *nf, char *rec)
1116{
1117    char *cp, tmp;
1118    int ret;
1119
1120    for (cp = rec; *cp != ':'; cp++)
1121	;
1122
1123    tmp = *(cp + 1);
1124    *(cp + 1) = '\0';
1125    ret = strcmp(nf, rec);
1126    *(cp + 1) = tmp;
1127
1128    return (ret);
1129}
1130