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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 $
064e1fb3 37 * $DragonFly: src/lib/libc/gen/getcap.c,v 1.3 2003/11/12 20:21:23 eirikn Exp $
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38 *
39 * @(#)getcap.c 8.3 (Berkeley) 3/25/94
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40 */
41
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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
64static size_t topreclen; /* toprec length */
65static char *toprec; /* Additional record specified by cgetset() */
66static int gottoprec; /* Flag indicating retrieval of toprecord */
67
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68static int cdbget (DB *, char **, char *);
69static int getent (char **, u_int *, char **, int, char *, int, char *);
70static int nfcmp (char *, char *);
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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(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 */
110char *
111cgetcap(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 */
162int
163cgetent(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 */
189static int
190getent(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 register char *r_end, *rp, **db_p;
197 int myfd, eof, foundit, retval, clen;
198 char *record, *cbuf;
199 int tc_not_resolved;
200 char pbuf[_POSIX_PATH_MAX];
201
202 /*
203 * Return with ``loop detected'' error if we've recursed more than
204 * MAX_RECURSION times.
205 */
206 if (depth > MAX_RECURSION)
207 return (-3);
208
209 /*
210 * Check if we have a top record from cgetset().
211 */
212 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
213 if ((record = malloc (topreclen + BFRAG)) == NULL) {
214 errno = ENOMEM;
215 return (-2);
216 }
217 (void)strcpy(record, toprec);
218 myfd = 0;
219 db_p = db_array;
220 rp = record + topreclen + 1;
221 r_end = rp + BFRAG;
222 goto tc_exp;
223 }
224 /*
225 * Allocate first chunk of memory.
226 */
227 if ((record = malloc(BFRAG)) == NULL) {
228 errno = ENOMEM;
229 return (-2);
230 }
231 r_end = record + BFRAG;
232 foundit = 0;
233 /*
234 * Loop through database array until finding the record.
235 */
236
237 for (db_p = db_array; *db_p != NULL; db_p++) {
238 eof = 0;
239
240 /*
241 * Open database if not already open.
242 */
243
244 if (fd >= 0) {
245 (void)lseek(fd, (off_t)0, SEEK_SET);
246 myfd = 0;
247 } else {
248 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
249 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
250 != NULL) {
251 free(record);
252 retval = cdbget(capdbp, &record, name);
253 if (retval < 0) {
254 /* no record available */
255 (void)capdbp->close(capdbp);
256 return (retval);
257 }
258 /* save the data; close frees it */
259 clen = strlen(record);
260 cbuf = malloc(clen + 1);
261 memcpy(cbuf, record, clen + 1);
262 if (capdbp->close(capdbp) < 0) {
263 free(cbuf);
264 return (-2);
265 }
266 *len = clen;
267 *cap = cbuf;
268 return (retval);
269 } else {
270 fd = _open(*db_p, O_RDONLY, 0);
271 if (fd < 0)
272 continue;
273 myfd = 1;
274 }
275 }
276 /*
277 * Find the requested capability record ...
278 */
279 {
280 char buf[BUFSIZ];
281 register char *b_end, *bp;
282 register int c;
283
284 /*
285 * Loop invariants:
286 * There is always room for one more character in record.
287 * R_end always points just past end of record.
288 * Rp always points just past last character in record.
289 * B_end always points just past last character in buf.
290 * Bp always points at next character in buf.
291 */
292 b_end = buf;
293 bp = buf;
294 for (;;) {
295
296 /*
297 * Read in a line implementing (\, newline)
298 * line continuation.
299 */
300 rp = record;
301 for (;;) {
302 if (bp >= b_end) {
303 int n;
304
305 n = _read(fd, buf, sizeof(buf));
306 if (n <= 0) {
307 if (myfd)
308 (void)_close(fd);
309 if (n < 0) {
310 free(record);
311 return (-2);
312 } else {
313 fd = -1;
314 eof = 1;
315 break;
316 }
317 }
318 b_end = buf+n;
319 bp = buf;
320 }
321
322 c = *bp++;
323 if (c == '\n') {
324 if (rp > record && *(rp-1) == '\\') {
325 rp--;
326 continue;
327 } else
328 break;
329 }
330 *rp++ = c;
331
332 /*
333 * Enforce loop invariant: if no room
334 * left in record buffer, try to get
335 * some more.
336 */
337 if (rp >= r_end) {
338 u_int pos;
339 size_t newsize;
340
341 pos = rp - record;
342 newsize = r_end - record + BFRAG;
343 record = reallocf(record, newsize);
344 if (record == NULL) {
345 errno = ENOMEM;
346 if (myfd)
347 (void)_close(fd);
348 return (-2);
349 }
350 r_end = record + newsize;
351 rp = record + pos;
352 }
353 }
354 /* loop invariant let's us do this */
355 *rp++ = '\0';
356
357 /*
358 * If encountered eof check next file.
359 */
360 if (eof)
361 break;
362
363 /*
364 * Toss blank lines and comments.
365 */
366 if (*record == '\0' || *record == '#')
367 continue;
368
369 /*
370 * See if this is the record we want ...
371 */
372 if (cgetmatch(record, name) == 0) {
373 if (nfield == NULL || !nfcmp(nfield, record)) {
374 foundit = 1;
375 break; /* found it! */
376 }
377 }
378 }
379 }
380 if (foundit)
381 break;
382 }
383
384 if (!foundit) {
385 free(record);
386 return (-1);
387 }
388
389 /*
390 * Got the capability record, but now we have to expand all tc=name
391 * references in it ...
392 */
393tc_exp: {
394 register char *newicap, *s;
395 register int newilen;
396 u_int ilen;
397 int diff, iret, tclen;
398 char *icap, *scan, *tc, *tcstart, *tcend;
399
400 /*
401 * Loop invariants:
402 * There is room for one more character in record.
403 * R_end points just past end of record.
404 * Rp points just past last character in record.
405 * Scan points at remainder of record that needs to be
406 * scanned for tc=name constructs.
407 */
408 scan = record;
409 tc_not_resolved = 0;
410 for (;;) {
411 if ((tc = cgetcap(scan, "tc", '=')) == NULL)
412 break;
413
414 /*
415 * Find end of tc=name and stomp on the trailing `:'
416 * (if present) so we can use it to call ourselves.
417 */
418 s = tc;
419 for (;;)
420 if (*s == '\0')
421 break;
422 else
423 if (*s++ == ':') {
424 *(s - 1) = '\0';
425 break;
426 }
427 tcstart = tc - 3;
428 tclen = s - tcstart;
429 tcend = s;
430
431 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
432 NULL);
433 newicap = icap; /* Put into a register. */
434 newilen = ilen;
435 if (iret != 0) {
436 /* an error */
437 if (iret < -1) {
438 if (myfd)
439 (void)_close(fd);
440 free(record);
441 return (iret);
442 }
443 if (iret == 1)
444 tc_not_resolved = 1;
445 /* couldn't resolve tc */
446 if (iret == -1) {
447 *(s - 1) = ':';
448 scan = s - 1;
449 tc_not_resolved = 1;
450 continue;
451
452 }
453 }
454 /* not interested in name field of tc'ed record */
455 s = newicap;
456 for (;;)
457 if (*s == '\0')
458 break;
459 else
460 if (*s++ == ':')
461 break;
462 newilen -= s - newicap;
463 newicap = s;
464
465 /* make sure interpolated record is `:'-terminated */
466 s += newilen;
467 if (*(s-1) != ':') {
468 *s = ':'; /* overwrite NUL with : */
469 newilen++;
470 }
471
472 /*
473 * Make sure there's enough room to insert the
474 * new record.
475 */
476 diff = newilen - tclen;
477 if (diff >= r_end - rp) {
478 u_int pos, tcpos, tcposend;
479 size_t newsize;
480
481 pos = rp - record;
482 newsize = r_end - record + diff + BFRAG;
483 tcpos = tcstart - record;
484 tcposend = tcend - record;
485 record = reallocf(record, newsize);
486 if (record == NULL) {
487 errno = ENOMEM;
488 if (myfd)
489 (void)_close(fd);
490 free(icap);
491 return (-2);
492 }
493 r_end = record + newsize;
494 rp = record + pos;
495 tcstart = record + tcpos;
496 tcend = record + tcposend;
497 }
498
499 /*
500 * Insert tc'ed record into our record.
501 */
502 s = tcstart + newilen;
503 bcopy(tcend, s, rp - tcend);
504 bcopy(newicap, tcstart, newilen);
505 rp += diff;
506 free(icap);
507
508 /*
509 * Start scan on `:' so next cgetcap works properly
510 * (cgetcap always skips first field).
511 */
512 scan = s-1;
513 }
514
515 }
516 /*
517 * Close file (if we opened it), give back any extra memory, and
518 * return capability, length and success.
519 */
520 if (myfd)
521 (void)_close(fd);
522 *len = rp - record - 1; /* don't count NUL */
523 if (r_end > rp)
524 if ((record =
525 reallocf(record, (size_t)(rp - record))) == NULL) {
526 errno = ENOMEM;
527 return (-2);
528 }
529
530 *cap = record;
531 if (tc_not_resolved)
532 return (1);
533 return (0);
534}
535
536static int
537cdbget(capdbp, bp, name)
538 DB *capdbp;
539 char **bp, *name;
540{
541 DBT key, data;
542
543 key.data = name;
544 key.size = strlen(name);
545
546 for (;;) {
547 /* Get the reference. */
548 switch(capdbp->get(capdbp, &key, &data, 0)) {
549 case -1:
550 return (-2);
551 case 1:
552 return (-1);
553 }
554
555 /* If not an index to another record, leave. */
556 if (((char *)data.data)[0] != SHADOW)
557 break;
558
559 key.data = (char *)data.data + 1;
560 key.size = data.size - 1;
561 }
562
563 *bp = (char *)data.data + 1;
564 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
565}
566
567/*
568 * Cgetmatch will return 0 if name is one of the names of the capability
569 * record buf, -1 if not.
570 */
571int
572cgetmatch(buf, name)
573 char *buf, *name;
574{
575 register char *np, *bp;
576
577 /*
578 * Start search at beginning of record.
579 */
580 bp = buf;
581 for (;;) {
582 /*
583 * Try to match a record name.
584 */
585 np = name;
586 for (;;)
587 if (*np == '\0')
588 if (*bp == '|' || *bp == ':' || *bp == '\0')
589 return (0);
590 else
591 break;
592 else
593 if (*bp++ != *np++)
594 break;
595
596 /*
597 * Match failed, skip to next name in record.
598 */
599 bp--; /* a '|' or ':' may have stopped the match */
600 for (;;)
601 if (*bp == '\0' || *bp == ':')
602 return (-1); /* match failed totally */
603 else
604 if (*bp++ == '|')
605 break; /* found next name */
606 }
607}
608
609
610
611
612
613int
614cgetfirst(buf, db_array)
615 char **buf, **db_array;
616{
617 (void)cgetclose();
618 return (cgetnext(buf, db_array));
619}
620
621static FILE *pfp;
622static int slash;
623static char **dbp;
624
625int
626cgetclose()
627{
628 if (pfp != NULL) {
629 (void)fclose(pfp);
630 pfp = NULL;
631 }
632 dbp = NULL;
633 gottoprec = 0;
634 slash = 0;
635 return(0);
636}
637
638/*
639 * Cgetnext() gets either the first or next entry in the logical database
640 * specified by db_array. It returns 0 upon completion of the database, 1
641 * upon returning an entry with more remaining, and -1 if an error occurs.
642 */
643int
644cgetnext(bp, db_array)
645 register char **bp;
646 char **db_array;
647{
648 size_t len;
649 int done, hadreaderr, i, savederrno, status;
650 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
651 u_int dummy;
652
653 if (dbp == NULL)
654 dbp = db_array;
655
656 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
657 (void)cgetclose();
658 return (-1);
659 }
660 for(;;) {
661 if (toprec && !gottoprec) {
662 gottoprec = 1;
663 line = toprec;
664 } else {
665 line = fgetln(pfp, &len);
666 if (line == NULL && pfp) {
667 hadreaderr = ferror(pfp);
668 if (hadreaderr)
669 savederrno = errno;
670 fclose(pfp);
671 pfp = NULL;
672 if (hadreaderr) {
673 cgetclose();
674 errno = savederrno;
675 return (-1);
676 } else {
677 if (*++dbp == NULL) {
678 (void)cgetclose();
679 return (0);
680 } else if ((pfp =
681 fopen(*dbp, "r")) == NULL) {
682 (void)cgetclose();
683 return (-1);
684 } else
685 continue;
686 }
687 } else
688 line[len - 1] = '\0';
689 if (len == 1) {
690 slash = 0;
691 continue;
692 }
693 if (isspace((unsigned char)*line) ||
694 *line == ':' || *line == '#' || slash) {
695 if (line[len - 2] == '\\')
696 slash = 1;
697 else
698 slash = 0;
699 continue;
700 }
701 if (line[len - 2] == '\\')
702 slash = 1;
703 else
704 slash = 0;
705 }
706
707
708 /*
709 * Line points to a name line.
710 */
711 i = 0;
712 done = 0;
713 np = nbuf;
714 for (;;) {
715 for (cp = line; *cp != '\0'; cp++) {
716 if (*cp == ':') {
717 *np++ = ':';
718 done = 1;
719 break;
720 }
721 if (*cp == '\\')
722 break;
723 *np++ = *cp;
724 }
725 if (done) {
726 *np = '\0';
727 break;
728 } else { /* name field extends beyond the line */
729 line = fgetln(pfp, &len);
730 if (line == NULL && pfp) {
731 /* Name extends beyond the EOF! */
732 hadreaderr = ferror(pfp);
733 if (hadreaderr)
734 savederrno = errno;
735 fclose(pfp);
736 pfp = NULL;
737 if (hadreaderr) {
738 cgetclose();
739 errno = savederrno;
740 return (-1);
741 } else {
742 cgetclose();
743 return (-1);
744 }
745 } else
746 line[len - 1] = '\0';
747 }
748 }
749 rp = buf;
750 for(cp = nbuf; *cp != '\0'; cp++)
751 if (*cp == '|' || *cp == ':')
752 break;
753 else
754 *rp++ = *cp;
755
756 *rp = '\0';
757 /*
758 * XXX
759 * Last argument of getent here should be nbuf if we want true
760 * sequential access in the case of duplicates.
761 * With NULL, getent will return the first entry found
762 * rather than the duplicate entry record. This is a
763 * matter of semantics that should be resolved.
764 */
765 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
766 if (status == -2 || status == -3)
767 (void)cgetclose();
768
769 return (status + 1);
770 }
771 /* NOTREACHED */
772}
773
774/*
775 * Cgetstr retrieves the value of the string capability cap from the
776 * capability record pointed to by buf. A pointer to a decoded, NUL
777 * terminated, malloc'd copy of the string is returned in the char *
778 * pointed to by str. The length of the string not including the trailing
779 * NUL is returned on success, -1 if the requested string capability
780 * couldn't be found, -2 if a system error was encountered (storage
781 * allocation failure).
782 */
783int
784cgetstr(buf, cap, str)
785 char *buf, *cap;
786 char **str;
787{
788 register u_int m_room;
789 register char *bp, *mp;
790 int len;
791 char *mem;
792
793 /*
794 * Find string capability cap
795 */
796 bp = cgetcap(buf, cap, '=');
797 if (bp == NULL)
798 return (-1);
799
800 /*
801 * Conversion / storage allocation loop ... Allocate memory in
802 * chunks SFRAG in size.
803 */
804 if ((mem = malloc(SFRAG)) == NULL) {
805 errno = ENOMEM;
806 return (-2); /* couldn't even allocate the first fragment */
807 }
808 m_room = SFRAG;
809 mp = mem;
810
811 while (*bp != ':' && *bp != '\0') {
812 /*
813 * Loop invariants:
814 * There is always room for one more character in mem.
815 * Mp always points just past last character in mem.
816 * Bp always points at next character in buf.
817 */
818 if (*bp == '^') {
819 bp++;
820 if (*bp == ':' || *bp == '\0')
821 break; /* drop unfinished escape */
822 if (*bp == '?') {
823 *mp++ = '\177';
824 bp++;
825 } else
826 *mp++ = *bp++ & 037;
827 } else if (*bp == '\\') {
828 bp++;
829 if (*bp == ':' || *bp == '\0')
830 break; /* drop unfinished escape */
831 if ('0' <= *bp && *bp <= '7') {
832 register int n, i;
833
834 n = 0;
835 i = 3; /* maximum of three octal digits */
836 do {
837 n = n * 8 + (*bp++ - '0');
838 } while (--i && '0' <= *bp && *bp <= '7');
839 *mp++ = n;
840 }
841 else switch (*bp++) {
842 case 'b': case 'B':
843 *mp++ = '\b';
844 break;
845 case 't': case 'T':
846 *mp++ = '\t';
847 break;
848 case 'n': case 'N':
849 *mp++ = '\n';
850 break;
851 case 'f': case 'F':
852 *mp++ = '\f';
853 break;
854 case 'r': case 'R':
855 *mp++ = '\r';
856 break;
857 case 'e': case 'E':
858 *mp++ = ESC;
859 break;
860 case 'c': case 'C':
861 *mp++ = ':';
862 break;
863 default:
864 /*
865 * Catches '\', '^', and
866 * everything else.
867 */
868 *mp++ = *(bp-1);
869 break;
870 }
871 } else
872 *mp++ = *bp++;
873 m_room--;
874
875 /*
876 * Enforce loop invariant: if no room left in current
877 * buffer, try to get some more.
878 */
879 if (m_room == 0) {
880 size_t size = mp - mem;
881
882 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
883 return (-2);
884 m_room = SFRAG;
885 mp = mem + size;
886 }
887 }
888 *mp++ = '\0'; /* loop invariant let's us do this */
889 m_room--;
890 len = mp - mem - 1;
891
892 /*
893 * Give back any extra memory and return value and success.
894 */
895 if (m_room != 0)
896 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
897 return (-2);
898 *str = mem;
899 return (len);
900}
901
902/*
903 * Cgetustr retrieves the value of the string capability cap from the
904 * capability record pointed to by buf. The difference between cgetustr()
905 * and cgetstr() is that cgetustr does not decode escapes but rather treats
906 * all characters literally. A pointer to a NUL terminated malloc'd
907 * copy of the string is returned in the char pointed to by str. The
908 * length of the string not including the trailing NUL is returned on success,
909 * -1 if the requested string capability couldn't be found, -2 if a system
910 * error was encountered (storage allocation failure).
911 */
912int
913cgetustr(buf, cap, str)
914 char *buf, *cap, **str;
915{
916 register u_int m_room;
917 register char *bp, *mp;
918 int len;
919 char *mem;
920
921 /*
922 * Find string capability cap
923 */
924 if ((bp = cgetcap(buf, cap, '=')) == NULL)
925 return (-1);
926
927 /*
928 * Conversion / storage allocation loop ... Allocate memory in
929 * chunks SFRAG in size.
930 */
931 if ((mem = malloc(SFRAG)) == NULL) {
932 errno = ENOMEM;
933 return (-2); /* couldn't even allocate the first fragment */
934 }
935 m_room = SFRAG;
936 mp = mem;
937
938 while (*bp != ':' && *bp != '\0') {
939 /*
940 * Loop invariants:
941 * There is always room for one more character in mem.
942 * Mp always points just past last character in mem.
943 * Bp always points at next character in buf.
944 */
945 *mp++ = *bp++;
946 m_room--;
947
948 /*
949 * Enforce loop invariant: if no room left in current
950 * buffer, try to get some more.
951 */
952 if (m_room == 0) {
953 size_t size = mp - mem;
954
955 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
956 return (-2);
957 m_room = SFRAG;
958 mp = mem + size;
959 }
960 }
961 *mp++ = '\0'; /* loop invariant let's us do this */
962 m_room--;
963 len = mp - mem - 1;
964
965 /*
966 * Give back any extra memory and return value and success.
967 */
968 if (m_room != 0)
969 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
970 return (-2);
971 *str = mem;
972 return (len);
973}
974
975/*
976 * Cgetnum retrieves the value of the numeric capability cap from the
977 * capability record pointed to by buf. The numeric value is returned in
978 * the long pointed to by num. 0 is returned on success, -1 if the requested
979 * numeric capability couldn't be found.
980 */
981int
982cgetnum(buf, cap, num)
983 char *buf, *cap;
984 long *num;
985{
986 register long n;
987 register int base, digit;
988 register char *bp;
989
990 /*
991 * Find numeric capability cap
992 */
993 bp = cgetcap(buf, cap, '#');
994 if (bp == NULL)
995 return (-1);
996
997 /*
998 * Look at value and determine numeric base:
999 * 0x... or 0X... hexadecimal,
1000 * else 0... octal,
1001 * else decimal.
1002 */
1003 if (*bp == '0') {
1004 bp++;
1005 if (*bp == 'x' || *bp == 'X') {
1006 bp++;
1007 base = 16;
1008 } else
1009 base = 8;
1010 } else
1011 base = 10;
1012
1013 /*
1014 * Conversion loop ...
1015 */
1016 n = 0;
1017 for (;;) {
1018 if ('0' <= *bp && *bp <= '9')
1019 digit = *bp - '0';
1020 else if ('a' <= *bp && *bp <= 'f')
1021 digit = 10 + *bp - 'a';
1022 else if ('A' <= *bp && *bp <= 'F')
1023 digit = 10 + *bp - 'A';
1024 else
1025 break;
1026
1027 if (digit >= base)
1028 break;
1029
1030 n = n * base + digit;
1031 bp++;
1032 }
1033
1034 /*
1035 * Return value and success.
1036 */
1037 *num = n;
1038 return (0);
1039}
1040
1041
1042/*
1043 * Compare name field of record.
1044 */
1045static int
1046nfcmp(nf, rec)
1047 char *nf, *rec;
1048{
1049 char *cp, tmp;
1050 int ret;
1051
1052 for (cp = rec; *cp != ':'; cp++)
1053 ;
1054
1055 tmp = *(cp + 1);
1056 *(cp + 1) = '\0';
1057 ret = strcmp(nf, rec);
1058 *(cp + 1) = tmp;
1059
1060 return (ret);
1061}