1/*-
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Casey Leedom of Lawrence Livermore National Laboratory.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static char sccsid[] = "@(#)getcap.c	8.3 (Berkeley) 3/25/94";
35#endif /* LIBC_SCCS and not lint */
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD$");
38
39#include "namespace.h"
40#include <sys/types.h>
41
42#include <ctype.h>
43#include <errno.h>
44#include <fcntl.h>
45#include <limits.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49#include <unistd.h>
50#include "un-namespace.h"
51
52#include <db.h>
53
54#define	BFRAG		1024
55#define	BSIZE		1024
56#define	ESC		('[' & 037)	/* ASCII ESC */
57#define	MAX_RECURSION	32		/* maximum getent recursion */
58#define	SFRAG		100		/* cgetstr mallocs in SFRAG chunks */
59
60#define RECOK	(char)0
61#define TCERR	(char)1
62#define	SHADOW	(char)2
63
64static size_t	 topreclen;	/* toprec length */
65static char	*toprec;	/* Additional record specified by cgetset() */
66static int	 gottoprec;	/* Flag indicating retrieval of toprecord */
67
68static int	cdbget(DB *, char **, const char *);
69static int 	getent(char **, u_int *, char **, int, const char *, int, char *);
70static int	nfcmp(char *, char *);
71
72/*
73 * Cgetset() allows the addition of a user specified buffer to be added
74 * to the database array, in effect "pushing" the buffer on top of the
75 * virtual database. 0 is returned on success, -1 on failure.
76 */
77int
78cgetset(const char *ent)
79{
80	if (ent == NULL) {
81		if (toprec)
82			free(toprec);
83                toprec = NULL;
84                topreclen = 0;
85                return (0);
86        }
87        topreclen = strlen(ent);
88        if ((toprec = malloc (topreclen + 1)) == NULL) {
89		errno = ENOMEM;
90                return (-1);
91	}
92	gottoprec = 0;
93        (void)strcpy(toprec, ent);
94        return (0);
95}
96
97/*
98 * Cgetcap searches the capability record buf for the capability cap with
99 * type `type'.  A pointer to the value of cap is returned on success, NULL
100 * if the requested capability couldn't be found.
101 *
102 * Specifying a type of ':' means that nothing should follow cap (:cap:).
103 * In this case a pointer to the terminating ':' or NUL will be returned if
104 * cap is found.
105 *
106 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
107 * return NULL.
108 */
109char *
110cgetcap(char *buf, const char *cap, int type)
111{
112	char *bp;
113	const char *cp;
114
115	bp = buf;
116	for (;;) {
117		/*
118		 * Skip past the current capability field - it's either the
119		 * name field if this is the first time through the loop, or
120		 * the remainder of a field whose name failed to match cap.
121		 */
122		for (;;)
123			if (*bp == '\0')
124				return (NULL);
125			else
126				if (*bp++ == ':')
127					break;
128
129		/*
130		 * Try to match (cap, type) in buf.
131		 */
132		for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
133			continue;
134		if (*cp != '\0')
135			continue;
136		if (*bp == '@')
137			return (NULL);
138		if (type == ':') {
139			if (*bp != '\0' && *bp != ':')
140				continue;
141			return(bp);
142		}
143		if (*bp != type)
144			continue;
145		bp++;
146		return (*bp == '@' ? NULL : bp);
147	}
148	/* NOTREACHED */
149}
150
151/*
152 * Cgetent extracts the capability record name from the NULL terminated file
153 * array db_array and returns a pointer to a malloc'd copy of it in buf.
154 * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
155 * cgetflag, and cgetstr, but may then be free'd.  0 is returned on success,
156 * -1 if the requested record couldn't be found, -2 if a system error was
157 * encountered (couldn't open/read a file, etc.), and -3 if a potential
158 * reference loop is detected.
159 */
160int
161cgetent(char **buf, char **db_array, const char *name)
162{
163	u_int dummy;
164
165	return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
166}
167
168/*
169 * Getent implements the functions of cgetent.  If fd is non-negative,
170 * *db_array has already been opened and fd is the open file descriptor.  We
171 * do this to save time and avoid using up file descriptors for tc=
172 * recursions.
173 *
174 * Getent returns the same success/failure codes as cgetent.  On success, a
175 * pointer to a malloc'ed capability record with all tc= capabilities fully
176 * expanded and its length (not including trailing ASCII NUL) are left in
177 * *cap and *len.
178 *
179 * Basic algorithm:
180 *	+ Allocate memory incrementally as needed in chunks of size BFRAG
181 *	  for capability buffer.
182 *	+ Recurse for each tc=name and interpolate result.  Stop when all
183 *	  names interpolated, a name can't be found, or depth exceeds
184 *	  MAX_RECURSION.
185 */
186static int
187getent(char **cap, u_int *len, char **db_array, int fd, const char *name,
188    int depth, char *nfield)
189{
190	DB *capdbp;
191	char *r_end, *rp, **db_p;
192	int myfd, eof, foundit, retval;
193	char *record, *cbuf;
194	int tc_not_resolved;
195	char pbuf[_POSIX_PATH_MAX];
196
197	/*
198	 * Return with ``loop detected'' error if we've recursed more than
199	 * MAX_RECURSION times.
200	 */
201	if (depth > MAX_RECURSION)
202		return (-3);
203
204	/*
205	 * Check if we have a top record from cgetset().
206         */
207	if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
208		if ((record = malloc (topreclen + BFRAG)) == NULL) {
209			errno = ENOMEM;
210			return (-2);
211		}
212		(void)strcpy(record, toprec);
213		myfd = 0;
214		db_p = db_array;
215		rp = record + topreclen + 1;
216		r_end = rp + BFRAG;
217		goto tc_exp;
218	}
219	/*
220	 * Allocate first chunk of memory.
221	 */
222	if ((record = malloc(BFRAG)) == NULL) {
223		errno = ENOMEM;
224		return (-2);
225	}
226	r_end = record + BFRAG;
227	foundit = 0;
228	/*
229	 * Loop through database array until finding the record.
230	 */
231
232	for (db_p = db_array; *db_p != NULL; db_p++) {
233		eof = 0;
234
235		/*
236		 * Open database if not already open.
237		 */
238
239		if (fd >= 0) {
240			(void)lseek(fd, (off_t)0, SEEK_SET);
241			myfd = 0;
242		} else {
243			(void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
244			if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
245			     != NULL) {
246				free(record);
247				retval = cdbget(capdbp, &record, name);
248				if (retval < 0) {
249					/* no record available */
250					(void)capdbp->close(capdbp);
251					return (retval);
252				}
253				/* save the data; close frees it */
254				cbuf = strdup(record);
255				if (capdbp->close(capdbp) < 0) {
256					free(cbuf);
257					return (-2);
258				}
259				if (cbuf == NULL) {
260					errno = ENOMEM;
261					return (-2);
262				}
263				*len = strlen(cbuf);
264				*cap = cbuf;
265				return (retval);
266			} else {
267				fd = _open(*db_p, O_RDONLY | O_CLOEXEC, 0);
268				if (fd < 0)
269					continue;
270				myfd = 1;
271			}
272		}
273		/*
274		 * Find the requested capability record ...
275		 */
276		{
277		char buf[BUFSIZ];
278		char *b_end, *bp;
279		int c;
280
281		/*
282		 * Loop invariants:
283		 *	There is always room for one more character in record.
284		 *	R_end always points just past end of record.
285		 *	Rp always points just past last character in record.
286		 *	B_end always points just past last character in buf.
287		 *	Bp always points at next character in buf.
288		 */
289		b_end = buf;
290		bp = buf;
291		for (;;) {
292
293			/*
294			 * Read in a line implementing (\, newline)
295			 * line continuation.
296			 */
297			rp = record;
298			for (;;) {
299				if (bp >= b_end) {
300					int n;
301
302					n = _read(fd, buf, sizeof(buf));
303					if (n <= 0) {
304						if (myfd)
305							(void)_close(fd);
306						if (n < 0) {
307							free(record);
308							return (-2);
309						} else {
310							fd = -1;
311							eof = 1;
312							break;
313						}
314					}
315					b_end = buf+n;
316					bp = buf;
317				}
318
319				c = *bp++;
320				if (c == '\n') {
321					if (rp > record && *(rp-1) == '\\') {
322						rp--;
323						continue;
324					} else
325						break;
326				}
327				*rp++ = c;
328
329				/*
330				 * Enforce loop invariant: if no room
331				 * left in record buffer, try to get
332				 * some more.
333				 */
334				if (rp >= r_end) {
335					u_int pos;
336					size_t newsize;
337
338					pos = rp - record;
339					newsize = r_end - record + BFRAG;
340					record = reallocf(record, newsize);
341					if (record == NULL) {
342						errno = ENOMEM;
343						if (myfd)
344							(void)_close(fd);
345						return (-2);
346					}
347					r_end = record + newsize;
348					rp = record + pos;
349				}
350			}
351				/* loop invariant let's us do this */
352			*rp++ = '\0';
353
354			/*
355			 * If encountered eof check next file.
356			 */
357			if (eof)
358				break;
359
360			/*
361			 * Toss blank lines and comments.
362			 */
363			if (*record == '\0' || *record == '#')
364				continue;
365
366			/*
367			 * See if this is the record we want ...
368			 */
369			if (cgetmatch(record, name) == 0) {
370				if (nfield == NULL || !nfcmp(nfield, record)) {
371					foundit = 1;
372					break;	/* found it! */
373				}
374			}
375		}
376	}
377		if (foundit)
378			break;
379	}
380
381	if (!foundit) {
382		free(record);
383		return (-1);
384	}
385
386	/*
387	 * Got the capability record, but now we have to expand all tc=name
388	 * references in it ...
389	 */
390tc_exp:	{
391		char *newicap, *s;
392		int newilen;
393		u_int ilen;
394		int diff, iret, tclen;
395		char *icap, *scan, *tc, *tcstart, *tcend;
396
397		/*
398		 * Loop invariants:
399		 *	There is room for one more character in record.
400		 *	R_end points just past end of record.
401		 *	Rp points just past last character in record.
402		 *	Scan points at remainder of record that needs to be
403		 *	scanned for tc=name constructs.
404		 */
405		scan = record;
406		tc_not_resolved = 0;
407		for (;;) {
408			if ((tc = cgetcap(scan, "tc", '=')) == NULL)
409				break;
410
411			/*
412			 * Find end of tc=name and stomp on the trailing `:'
413			 * (if present) so we can use it to call ourselves.
414			 */
415			s = tc;
416			for (;;)
417				if (*s == '\0')
418					break;
419				else
420					if (*s++ == ':') {
421						*(s - 1) = '\0';
422						break;
423					}
424			tcstart = tc - 3;
425			tclen = s - tcstart;
426			tcend = s;
427
428			iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
429				      NULL);
430			newicap = icap;		/* Put into a register. */
431			newilen = ilen;
432			if (iret != 0) {
433				/* an error */
434				if (iret < -1) {
435					if (myfd)
436						(void)_close(fd);
437					free(record);
438					return (iret);
439				}
440				if (iret == 1)
441					tc_not_resolved = 1;
442				/* couldn't resolve tc */
443				if (iret == -1) {
444					*(s - 1) = ':';
445					scan = s - 1;
446					tc_not_resolved = 1;
447					continue;
448
449				}
450			}
451			/* not interested in name field of tc'ed record */
452			s = newicap;
453			for (;;)
454				if (*s == '\0')
455					break;
456				else
457					if (*s++ == ':')
458						break;
459			newilen -= s - newicap;
460			newicap = s;
461
462			/* make sure interpolated record is `:'-terminated */
463			s += newilen;
464			if (*(s-1) != ':') {
465				*s = ':';	/* overwrite NUL with : */
466				newilen++;
467			}
468
469			/*
470			 * Make sure there's enough room to insert the
471			 * new record.
472			 */
473			diff = newilen - tclen;
474			if (diff >= r_end - rp) {
475				u_int pos, tcpos, tcposend;
476				size_t newsize;
477
478				pos = rp - record;
479				newsize = r_end - record + diff + BFRAG;
480				tcpos = tcstart - record;
481				tcposend = tcend - record;
482				record = reallocf(record, newsize);
483				if (record == NULL) {
484					errno = ENOMEM;
485					if (myfd)
486						(void)_close(fd);
487					free(icap);
488					return (-2);
489				}
490				r_end = record + newsize;
491				rp = record + pos;
492				tcstart = record + tcpos;
493				tcend = record + tcposend;
494			}
495
496			/*
497			 * Insert tc'ed record into our record.
498			 */
499			s = tcstart + newilen;
500			bcopy(tcend, s, rp - tcend);
501			bcopy(newicap, tcstart, newilen);
502			rp += diff;
503			free(icap);
504
505			/*
506			 * Start scan on `:' so next cgetcap works properly
507			 * (cgetcap always skips first field).
508			 */
509			scan = s-1;
510		}
511
512	}
513	/*
514	 * Close file (if we opened it), give back any extra memory, and
515	 * return capability, length and success.
516	 */
517	if (myfd)
518		(void)_close(fd);
519	*len = rp - record - 1;	/* don't count NUL */
520	if (r_end > rp)
521		if ((record =
522		     reallocf(record, (size_t)(rp - record))) == NULL) {
523			errno = ENOMEM;
524			return (-2);
525		}
526
527	*cap = record;
528	if (tc_not_resolved)
529		return (1);
530	return (0);
531}
532
533static int
534cdbget(DB *capdbp, char **bp, const char *name)
535{
536	DBT key, data;
537	char *namebuf;
538
539	namebuf = strdup(name);
540	if (namebuf == NULL)
541		return (-2);
542	key.data = namebuf;
543	key.size = strlen(namebuf);
544
545	for (;;) {
546		/* Get the reference. */
547		switch(capdbp->get(capdbp, &key, &data, 0)) {
548		case -1:
549			free(namebuf);
550			return (-2);
551		case 1:
552			free(namebuf);
553			return (-1);
554		}
555
556		/* If not an index to another record, leave. */
557		if (((char *)data.data)[0] != SHADOW)
558			break;
559
560		key.data = (char *)data.data + 1;
561		key.size = data.size - 1;
562	}
563
564	*bp = (char *)data.data + 1;
565	free(namebuf);
566	return (((char *)(data.data))[0] == TCERR ? 1 : 0);
567}
568
569/*
570 * Cgetmatch will return 0 if name is one of the names of the capability
571 * record buf, -1 if not.
572 */
573int
574cgetmatch(const char *buf, const char *name)
575{
576	const char *np, *bp;
577
578	if (name == NULL || *name == '\0')
579		return -1;
580
581	/*
582	 * Start search at beginning of record.
583	 */
584	bp = buf;
585	for (;;) {
586		/*
587		 * Try to match a record name.
588		 */
589		np = name;
590		for (;;)
591			if (*np == '\0')
592				if (*bp == '|' || *bp == ':' || *bp == '\0')
593					return (0);
594				else
595					break;
596			else
597				if (*bp++ != *np++)
598					break;
599
600		/*
601		 * Match failed, skip to next name in record.
602		 */
603		bp--;	/* a '|' or ':' may have stopped the match */
604		for (;;)
605			if (*bp == '\0' || *bp == ':')
606				return (-1);	/* match failed totally */
607			else
608				if (*bp++ == '|')
609					break;	/* found next name */
610	}
611}
612
613
614
615
616
617int
618cgetfirst(char **buf, char **db_array)
619{
620	(void)cgetclose();
621	return (cgetnext(buf, db_array));
622}
623
624static FILE *pfp;
625static int slash;
626static char **dbp;
627
628int
629cgetclose(void)
630{
631	if (pfp != NULL) {
632		(void)fclose(pfp);
633		pfp = NULL;
634	}
635	dbp = NULL;
636	gottoprec = 0;
637	slash = 0;
638	return(0);
639}
640
641/*
642 * Cgetnext() gets either the first or next entry in the logical database
643 * specified by db_array.  It returns 0 upon completion of the database, 1
644 * upon returning an entry with more remaining, and -1 if an error occurs.
645 */
646int
647cgetnext(char **bp, char **db_array)
648{
649	size_t len;
650	int done, hadreaderr, savederrno, status;
651	char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
652	u_int dummy;
653
654	if (dbp == NULL)
655		dbp = db_array;
656
657	if (pfp == NULL && (pfp = fopen(*dbp, "re")) == NULL) {
658		(void)cgetclose();
659		return (-1);
660	}
661	for (;;) {
662		if (toprec && !gottoprec) {
663			gottoprec = 1;
664			line = toprec;
665		} else {
666			line = fgetln(pfp, &len);
667			if (line == NULL && pfp) {
668				hadreaderr = ferror(pfp);
669				if (hadreaderr)
670					savederrno = errno;
671				fclose(pfp);
672				pfp = NULL;
673				if (hadreaderr) {
674					cgetclose();
675					errno = savederrno;
676					return (-1);
677				} else {
678					if (*++dbp == NULL) {
679						(void)cgetclose();
680						return (0);
681					} else if ((pfp =
682					    fopen(*dbp, "re")) == NULL) {
683						(void)cgetclose();
684						return (-1);
685					} else
686						continue;
687				}
688			} else
689				line[len - 1] = '\0';
690			if (len == 1) {
691				slash = 0;
692				continue;
693			}
694			if (isspace((unsigned char)*line) ||
695			    *line == ':' || *line == '#' || slash) {
696				if (line[len - 2] == '\\')
697					slash = 1;
698				else
699					slash = 0;
700				continue;
701			}
702			if (line[len - 2] == '\\')
703				slash = 1;
704			else
705				slash = 0;
706		}
707
708
709		/*
710		 * Line points to a name line.
711		 */
712		done = 0;
713		np = nbuf;
714		for (;;) {
715			for (cp = line; *cp != '\0'; cp++) {
716				if (*cp == ':') {
717					*np++ = ':';
718					done = 1;
719					break;
720				}
721				if (*cp == '\\')
722					break;
723				*np++ = *cp;
724			}
725			if (done) {
726				*np = '\0';
727				break;
728			} else { /* name field extends beyond the line */
729				line = fgetln(pfp, &len);
730				if (line == NULL && pfp) {
731					/* Name extends beyond the EOF! */
732					hadreaderr = ferror(pfp);
733					if (hadreaderr)
734						savederrno = errno;
735					fclose(pfp);
736					pfp = NULL;
737					if (hadreaderr) {
738						cgetclose();
739						errno = savederrno;
740						return (-1);
741					} else {
742						cgetclose();
743						return (-1);
744					}
745				} else
746					line[len - 1] = '\0';
747			}
748		}
749		rp = buf;
750		for(cp = nbuf; *cp != '\0'; cp++)
751			if (*cp == '|' || *cp == ':')
752				break;
753			else
754				*rp++ = *cp;
755
756		*rp = '\0';
757		/*
758		 * XXX
759		 * Last argument of getent here should be nbuf if we want true
760		 * sequential access in the case of duplicates.
761		 * With NULL, getent will return the first entry found
762		 * rather than the duplicate entry record.  This is a
763		 * matter of semantics that should be resolved.
764		 */
765		status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
766		if (status == -2 || status == -3)
767			(void)cgetclose();
768
769		return (status + 1);
770	}
771	/* NOTREACHED */
772}
773
774/*
775 * Cgetstr retrieves the value of the string capability cap from the
776 * capability record pointed to by buf.  A pointer to a decoded, NUL
777 * terminated, malloc'd copy of the string is returned in the char *
778 * pointed to by str.  The length of the string not including the trailing
779 * NUL is returned on success, -1 if the requested string capability
780 * couldn't be found, -2 if a system error was encountered (storage
781 * allocation failure).
782 */
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