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[dragonfly.git] / lib / libc / gen / getcap.c
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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 * $FreeBSD: src/lib/libc/gen/getcap.c,v 1.11.2.2 2001/01/15 06:48:09 gad Exp $
37 */
38
39#if defined(LIBC_SCCS) && !defined(lint)
40static char sccsid[] = "@(#)getcap.c 8.3 (Berkeley) 3/25/94";
41#endif /* LIBC_SCCS and not lint */
42
43#include <sys/types.h>
44
45#include <ctype.h>
46#include <db.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
55#define BFRAG 1024
56#define BSIZE 1024
57#define ESC ('[' & 037) /* ASCII ESC */
58#define MAX_RECURSION 32 /* maximum getent recursion */
59#define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */
60
61#define RECOK (char)0
62#define TCERR (char)1
63#define SHADOW (char)2
64
65static size_t topreclen; /* toprec length */
66static char *toprec; /* Additional record specified by cgetset() */
67static int gottoprec; /* Flag indicating retrieval of toprecord */
68
69static int cdbget __P((DB *, char **, char *));
70static int getent __P((char **, u_int *, char **, int, char *, int, char *));
71static int nfcmp __P((char *, char *));
72
73/*
74 * Cgetset() allows the addition of a user specified buffer to be added
75 * to the database array, in effect "pushing" the buffer on top of the
76 * virtual database. 0 is returned on success, -1 on failure.
77 */
78int
79cgetset(ent)
80 char *ent;
81{
82 if (ent == NULL) {
83 if (toprec)
84 free(toprec);
85 toprec = NULL;
86 topreclen = 0;
87 return (0);
88 }
89 topreclen = strlen(ent);
90 if ((toprec = malloc (topreclen + 1)) == NULL) {
91 errno = ENOMEM;
92 return (-1);
93 }
94 gottoprec = 0;
95 (void)strcpy(toprec, ent);
96 return (0);
97}
98
99/*
100 * Cgetcap searches the capability record buf for the capability cap with
101 * type `type'. A pointer to the value of cap is returned on success, NULL
102 * if the requested capability couldn't be found.
103 *
104 * Specifying a type of ':' means that nothing should follow cap (:cap:).
105 * In this case a pointer to the terminating ':' or NUL will be returned if
106 * cap is found.
107 *
108 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
109 * return NULL.
110 */
111char *
112cgetcap(buf, cap, type)
113 char *buf, *cap;
114 int type;
115{
116 register char *bp, *cp;
117
118 bp = buf;
119 for (;;) {
120 /*
121 * Skip past the current capability field - it's either the
122 * name field if this is the first time through the loop, or
123 * the remainder of a field whose name failed to match cap.
124 */
125 for (;;)
126 if (*bp == '\0')
127 return (NULL);
128 else
129 if (*bp++ == ':')
130 break;
131
132 /*
133 * Try to match (cap, type) in buf.
134 */
135 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
136 continue;
137 if (*cp != '\0')
138 continue;
139 if (*bp == '@')
140 return (NULL);
141 if (type == ':') {
142 if (*bp != '\0' && *bp != ':')
143 continue;
144 return(bp);
145 }
146 if (*bp != type)
147 continue;
148 bp++;
149 return (*bp == '@' ? NULL : bp);
150 }
151 /* NOTREACHED */
152}
153
154/*
155 * Cgetent extracts the capability record name from the NULL terminated file
156 * array db_array and returns a pointer to a malloc'd copy of it in buf.
157 * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
158 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success,
159 * -1 if the requested record couldn't be found, -2 if a system error was
160 * encountered (couldn't open/read a file, etc.), and -3 if a potential
161 * reference loop is detected.
162 */
163int
164cgetent(buf, db_array, name)
165 char **buf, **db_array, *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(cap, len, db_array, fd, name, depth, nfield)
192 char **cap, **db_array, *name, *nfield;
193 u_int *len;
194 int fd, depth;
195{
196 DB *capdbp;
197 register char *r_end, *rp, **db_p;
198 int myfd, eof, foundit, retval, clen;
199 char *record, *cbuf;
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, SEEK_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 (retval < 0) {
255 /* no record available */
256 (void)capdbp->close(capdbp);
257 return (retval);
258 }
259 /* save the data; close frees it */
260 clen = strlen(record);
261 cbuf = malloc(clen + 1);
262 memcpy(cbuf, record, clen + 1);
263 if (capdbp->close(capdbp) < 0) {
264 free(cbuf);
265 return (-2);
266 }
267 *len = clen;
268 *cap = cbuf;
269 return (retval);
270 } else {
271 fd = _open(*db_p, O_RDONLY, 0);
272 if (fd < 0)
273 continue;
274 myfd = 1;
275 }
276 }
277 /*
278 * Find the requested capability record ...
279 */
280 {
281 char buf[BUFSIZ];
282 register char *b_end, *bp;
283 register int c;
284
285 /*
286 * Loop invariants:
287 * There is always room for one more character in record.
288 * R_end always points just past end of record.
289 * Rp always points just past last character in record.
290 * B_end always points just past last character in buf.
291 * Bp always points at next character in buf.
292 */
293 b_end = buf;
294 bp = buf;
295 for (;;) {
296
297 /*
298 * Read in a line implementing (\, newline)
299 * line continuation.
300 */
301 rp = record;
302 for (;;) {
303 if (bp >= b_end) {
304 int n;
305
306 n = _read(fd, buf, sizeof(buf));
307 if (n <= 0) {
308 if (myfd)
309 (void)_close(fd);
310 if (n < 0) {
311 free(record);
312 return (-2);
313 } else {
314 fd = -1;
315 eof = 1;
316 break;
317 }
318 }
319 b_end = buf+n;
320 bp = buf;
321 }
322
323 c = *bp++;
324 if (c == '\n') {
325 if (rp > record && *(rp-1) == '\\') {
326 rp--;
327 continue;
328 } else
329 break;
330 }
331 *rp++ = c;
332
333 /*
334 * Enforce loop invariant: if no room
335 * left in record buffer, try to get
336 * some more.
337 */
338 if (rp >= r_end) {
339 u_int pos;
340 size_t newsize;
341
342 pos = rp - record;
343 newsize = r_end - record + BFRAG;
344 record = reallocf(record, newsize);
345 if (record == NULL) {
346 errno = ENOMEM;
347 if (myfd)
348 (void)_close(fd);
349 return (-2);
350 }
351 r_end = record + newsize;
352 rp = record + pos;
353 }
354 }
355 /* loop invariant let's us do this */
356 *rp++ = '\0';
357
358 /*
359 * If encountered eof check next file.
360 */
361 if (eof)
362 break;
363
364 /*
365 * Toss blank lines and comments.
366 */
367 if (*record == '\0' || *record == '#')
368 continue;
369
370 /*
371 * See if this is the record we want ...
372 */
373 if (cgetmatch(record, name) == 0) {
374 if (nfield == NULL || !nfcmp(nfield, record)) {
375 foundit = 1;
376 break; /* found it! */
377 }
378 }
379 }
380 }
381 if (foundit)
382 break;
383 }
384
385 if (!foundit) {
386 free(record);
387 return (-1);
388 }
389
390 /*
391 * Got the capability record, but now we have to expand all tc=name
392 * references in it ...
393 */
394tc_exp: {
395 register char *newicap, *s;
396 register int newilen;
397 u_int ilen;
398 int diff, iret, tclen;
399 char *icap, *scan, *tc, *tcstart, *tcend;
400
401 /*
402 * Loop invariants:
403 * There is room for one more character in record.
404 * R_end points just past end of record.
405 * Rp points just past last character in record.
406 * Scan points at remainder of record that needs to be
407 * scanned for tc=name constructs.
408 */
409 scan = record;
410 tc_not_resolved = 0;
411 for (;;) {
412 if ((tc = cgetcap(scan, "tc", '=')) == NULL)
413 break;
414
415 /*
416 * Find end of tc=name and stomp on the trailing `:'
417 * (if present) so we can use it to call ourselves.
418 */
419 s = tc;
420 for (;;)
421 if (*s == '\0')
422 break;
423 else
424 if (*s++ == ':') {
425 *(s - 1) = '\0';
426 break;
427 }
428 tcstart = tc - 3;
429 tclen = s - tcstart;
430 tcend = s;
431
432 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
433 NULL);
434 newicap = icap; /* Put into a register. */
435 newilen = ilen;
436 if (iret != 0) {
437 /* an error */
438 if (iret < -1) {
439 if (myfd)
440 (void)_close(fd);
441 free(record);
442 return (iret);
443 }
444 if (iret == 1)
445 tc_not_resolved = 1;
446 /* couldn't resolve tc */
447 if (iret == -1) {
448 *(s - 1) = ':';
449 scan = s - 1;
450 tc_not_resolved = 1;
451 continue;
452
453 }
454 }
455 /* not interested in name field of tc'ed record */
456 s = newicap;
457 for (;;)
458 if (*s == '\0')
459 break;
460 else
461 if (*s++ == ':')
462 break;
463 newilen -= s - newicap;
464 newicap = s;
465
466 /* make sure interpolated record is `:'-terminated */
467 s += newilen;
468 if (*(s-1) != ':') {
469 *s = ':'; /* overwrite NUL with : */
470 newilen++;
471 }
472
473 /*
474 * Make sure there's enough room to insert the
475 * new record.
476 */
477 diff = newilen - tclen;
478 if (diff >= r_end - rp) {
479 u_int pos, tcpos, tcposend;
480 size_t newsize;
481
482 pos = rp - record;
483 newsize = r_end - record + diff + BFRAG;
484 tcpos = tcstart - record;
485 tcposend = tcend - record;
486 record = reallocf(record, newsize);
487 if (record == NULL) {
488 errno = ENOMEM;
489 if (myfd)
490 (void)_close(fd);
491 free(icap);
492 return (-2);
493 }
494 r_end = record + newsize;
495 rp = record + pos;
496 tcstart = record + tcpos;
497 tcend = record + tcposend;
498 }
499
500 /*
501 * Insert tc'ed record into our record.
502 */
503 s = tcstart + newilen;
504 bcopy(tcend, s, rp - tcend);
505 bcopy(newicap, tcstart, newilen);
506 rp += diff;
507 free(icap);
508
509 /*
510 * Start scan on `:' so next cgetcap works properly
511 * (cgetcap always skips first field).
512 */
513 scan = s-1;
514 }
515
516 }
517 /*
518 * Close file (if we opened it), give back any extra memory, and
519 * return capability, length and success.
520 */
521 if (myfd)
522 (void)_close(fd);
523 *len = rp - record - 1; /* don't count NUL */
524 if (r_end > rp)
525 if ((record =
526 reallocf(record, (size_t)(rp - record))) == NULL) {
527 errno = ENOMEM;
528 return (-2);
529 }
530
531 *cap = record;
532 if (tc_not_resolved)
533 return (1);
534 return (0);
535}
536
537static int
538cdbget(capdbp, bp, name)
539 DB *capdbp;
540 char **bp, *name;
541{
542 DBT key, data;
543
544 key.data = name;
545 key.size = strlen(name);
546
547 for (;;) {
548 /* Get the reference. */
549 switch(capdbp->get(capdbp, &key, &data, 0)) {
550 case -1:
551 return (-2);
552 case 1:
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 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
566}
567
568/*
569 * Cgetmatch will return 0 if name is one of the names of the capability
570 * record buf, -1 if not.
571 */
572int
573cgetmatch(buf, name)
574 char *buf, *name;
575{
576 register char *np, *bp;
577
578 /*
579 * Start search at beginning of record.
580 */
581 bp = buf;
582 for (;;) {
583 /*
584 * Try to match a record name.
585 */
586 np = name;
587 for (;;)
588 if (*np == '\0')
589 if (*bp == '|' || *bp == ':' || *bp == '\0')
590 return (0);
591 else
592 break;
593 else
594 if (*bp++ != *np++)
595 break;
596
597 /*
598 * Match failed, skip to next name in record.
599 */
600 bp--; /* a '|' or ':' may have stopped the match */
601 for (;;)
602 if (*bp == '\0' || *bp == ':')
603 return (-1); /* match failed totally */
604 else
605 if (*bp++ == '|')
606 break; /* found next name */
607 }
608}
609
610
611
612
613
614int
615cgetfirst(buf, db_array)
616 char **buf, **db_array;
617{
618 (void)cgetclose();
619 return (cgetnext(buf, db_array));
620}
621
622static FILE *pfp;
623static int slash;
624static char **dbp;
625
626int
627cgetclose()
628{
629 if (pfp != NULL) {
630 (void)fclose(pfp);
631 pfp = NULL;
632 }
633 dbp = NULL;
634 gottoprec = 0;
635 slash = 0;
636 return(0);
637}
638
639/*
640 * Cgetnext() gets either the first or next entry in the logical database
641 * specified by db_array. It returns 0 upon completion of the database, 1
642 * upon returning an entry with more remaining, and -1 if an error occurs.
643 */
644int
645cgetnext(bp, db_array)
646 register char **bp;
647 char **db_array;
648{
649 size_t len;
650 int done, hadreaderr, i, 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, "r")) == 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, "r")) == 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 i = 0;
713 done = 0;
714 np = nbuf;
715 for (;;) {
716 for (cp = line; *cp != '\0'; cp++) {
717 if (*cp == ':') {
718 *np++ = ':';
719 done = 1;
720 break;
721 }
722 if (*cp == '\\')
723 break;
724 *np++ = *cp;
725 }
726 if (done) {
727 *np = '\0';
728 break;
729 } else { /* name field extends beyond the line */
730 line = fgetln(pfp, &len);
731 if (line == NULL && pfp) {
732 /* Name extends beyond the EOF! */
733 hadreaderr = ferror(pfp);
734 if (hadreaderr)
735 savederrno = errno;
736 fclose(pfp);
737 pfp = NULL;
738 if (hadreaderr) {
739 cgetclose();
740 errno = savederrno;
741 return (-1);
742 } else {
743 cgetclose();
744 return (-1);
745 }
746 } else
747 line[len - 1] = '\0';
748 }
749 }
750 rp = buf;
751 for(cp = nbuf; *cp != '\0'; cp++)
752 if (*cp == '|' || *cp == ':')
753 break;
754 else
755 *rp++ = *cp;
756
757 *rp = '\0';
758 /*
759 * XXX
760 * Last argument of getent here should be nbuf if we want true
761 * sequential access in the case of duplicates.
762 * With NULL, getent will return the first entry found
763 * rather than the duplicate entry record. This is a
764 * matter of semantics that should be resolved.
765 */
766 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
767 if (status == -2 || status == -3)
768 (void)cgetclose();
769
770 return (status + 1);
771 }
772 /* NOTREACHED */
773}
774
775/*
776 * Cgetstr retrieves the value of the string capability cap from the
777 * capability record pointed to by buf. A pointer to a decoded, NUL
778 * terminated, malloc'd copy of the string is returned in the char *
779 * pointed to by str. The length of the string not including the trailing
780 * NUL is returned on success, -1 if the requested string capability
781 * couldn't be found, -2 if a system error was encountered (storage
782 * allocation failure).
783 */
784int
785cgetstr(buf, cap, str)
786 char *buf, *cap;
787 char **str;
788{
789 register u_int m_room;
790 register char *bp, *mp;
791 int len;
792 char *mem;
793
794 /*
795 * Find string capability cap
796 */
797 bp = cgetcap(buf, cap, '=');
798 if (bp == NULL)
799 return (-1);
800
801 /*
802 * Conversion / storage allocation loop ... Allocate memory in
803 * chunks SFRAG in size.
804 */
805 if ((mem = malloc(SFRAG)) == NULL) {
806 errno = ENOMEM;
807 return (-2); /* couldn't even allocate the first fragment */
808 }
809 m_room = SFRAG;
810 mp = mem;
811
812 while (*bp != ':' && *bp != '\0') {
813 /*
814 * Loop invariants:
815 * There is always room for one more character in mem.
816 * Mp always points just past last character in mem.
817 * Bp always points at next character in buf.
818 */
819 if (*bp == '^') {
820 bp++;
821 if (*bp == ':' || *bp == '\0')
822 break; /* drop unfinished escape */
823 if (*bp == '?') {
824 *mp++ = '\177';
825 bp++;
826 } else
827 *mp++ = *bp++ & 037;
828 } else if (*bp == '\\') {
829 bp++;
830 if (*bp == ':' || *bp == '\0')
831 break; /* drop unfinished escape */
832 if ('0' <= *bp && *bp <= '7') {
833 register int n, i;
834
835 n = 0;
836 i = 3; /* maximum of three octal digits */
837 do {
838 n = n * 8 + (*bp++ - '0');
839 } while (--i && '0' <= *bp && *bp <= '7');
840 *mp++ = n;
841 }
842 else switch (*bp++) {
843 case 'b': case 'B':
844 *mp++ = '\b';
845 break;
846 case 't': case 'T':
847 *mp++ = '\t';
848 break;
849 case 'n': case 'N':
850 *mp++ = '\n';
851 break;
852 case 'f': case 'F':
853 *mp++ = '\f';
854 break;
855 case 'r': case 'R':
856 *mp++ = '\r';
857 break;
858 case 'e': case 'E':
859 *mp++ = ESC;
860 break;
861 case 'c': case 'C':
862 *mp++ = ':';
863 break;
864 default:
865 /*
866 * Catches '\', '^', and
867 * everything else.
868 */
869 *mp++ = *(bp-1);
870 break;
871 }
872 } else
873 *mp++ = *bp++;
874 m_room--;
875
876 /*
877 * Enforce loop invariant: if no room left in current
878 * buffer, try to get some more.
879 */
880 if (m_room == 0) {
881 size_t size = mp - mem;
882
883 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
884 return (-2);
885 m_room = SFRAG;
886 mp = mem + size;
887 }
888 }
889 *mp++ = '\0'; /* loop invariant let's us do this */
890 m_room--;
891 len = mp - mem - 1;
892
893 /*
894 * Give back any extra memory and return value and success.
895 */
896 if (m_room != 0)
897 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
898 return (-2);
899 *str = mem;
900 return (len);
901}
902
903/*
904 * Cgetustr retrieves the value of the string capability cap from the
905 * capability record pointed to by buf. The difference between cgetustr()
906 * and cgetstr() is that cgetustr does not decode escapes but rather treats
907 * all characters literally. A pointer to a NUL terminated malloc'd
908 * copy of the string is returned in the char pointed to by str. The
909 * length of the string not including the trailing NUL is returned on success,
910 * -1 if the requested string capability couldn't be found, -2 if a system
911 * error was encountered (storage allocation failure).
912 */
913int
914cgetustr(buf, cap, str)
915 char *buf, *cap, **str;
916{
917 register u_int m_room;
918 register char *bp, *mp;
919 int len;
920 char *mem;
921
922 /*
923 * Find string capability cap
924 */
925 if ((bp = cgetcap(buf, cap, '=')) == NULL)
926 return (-1);
927
928 /*
929 * Conversion / storage allocation loop ... Allocate memory in
930 * chunks SFRAG in size.
931 */
932 if ((mem = malloc(SFRAG)) == NULL) {
933 errno = ENOMEM;
934 return (-2); /* couldn't even allocate the first fragment */
935 }
936 m_room = SFRAG;
937 mp = mem;
938
939 while (*bp != ':' && *bp != '\0') {
940 /*
941 * Loop invariants:
942 * There is always room for one more character in mem.
943 * Mp always points just past last character in mem.
944 * Bp always points at next character in buf.
945 */
946 *mp++ = *bp++;
947 m_room--;
948
949 /*
950 * Enforce loop invariant: if no room left in current
951 * buffer, try to get some more.
952 */
953 if (m_room == 0) {
954 size_t size = mp - mem;
955
956 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
957 return (-2);
958 m_room = SFRAG;
959 mp = mem + size;
960 }
961 }
962 *mp++ = '\0'; /* loop invariant let's us do this */
963 m_room--;
964 len = mp - mem - 1;
965
966 /*
967 * Give back any extra memory and return value and success.
968 */
969 if (m_room != 0)
970 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
971 return (-2);
972 *str = mem;
973 return (len);
974}
975
976/*
977 * Cgetnum retrieves the value of the numeric capability cap from the
978 * capability record pointed to by buf. The numeric value is returned in
979 * the long pointed to by num. 0 is returned on success, -1 if the requested
980 * numeric capability couldn't be found.
981 */
982int
983cgetnum(buf, cap, num)
984 char *buf, *cap;
985 long *num;
986{
987 register long n;
988 register int base, digit;
989 register char *bp;
990
991 /*
992 * Find numeric capability cap
993 */
994 bp = cgetcap(buf, cap, '#');
995 if (bp == NULL)
996 return (-1);
997
998 /*
999 * Look at value and determine numeric base:
1000 * 0x... or 0X... hexadecimal,
1001 * else 0... octal,
1002 * else decimal.
1003 */
1004 if (*bp == '0') {
1005 bp++;
1006 if (*bp == 'x' || *bp == 'X') {
1007 bp++;
1008 base = 16;
1009 } else
1010 base = 8;
1011 } else
1012 base = 10;
1013
1014 /*
1015 * Conversion loop ...
1016 */
1017 n = 0;
1018 for (;;) {
1019 if ('0' <= *bp && *bp <= '9')
1020 digit = *bp - '0';
1021 else if ('a' <= *bp && *bp <= 'f')
1022 digit = 10 + *bp - 'a';
1023 else if ('A' <= *bp && *bp <= 'F')
1024 digit = 10 + *bp - 'A';
1025 else
1026 break;
1027
1028 if (digit >= base)
1029 break;
1030
1031 n = n * base + digit;
1032 bp++;
1033 }
1034
1035 /*
1036 * Return value and success.
1037 */
1038 *num = n;
1039 return (0);
1040}
1041
1042
1043/*
1044 * Compare name field of record.
1045 */
1046static int
1047nfcmp(nf, rec)
1048 char *nf, *rec;
1049{
1050 char *cp, tmp;
1051 int ret;
1052
1053 for (cp = rec; *cp != ':'; cp++)
1054 ;
1055
1056 tmp = *(cp + 1);
1057 *(cp + 1) = '\0';
1058 ret = strcmp(nf, rec);
1059 *(cp + 1) = tmp;
1060
1061 return (ret);
1062}