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[apple/libc.git] / gen / FreeBSD / getcap.c
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)
34 static 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: src/lib/libc/gen/getcap.c,v 1.23 2009/11/25 04:45:45 wollman Exp $");
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
64 static size_t topreclen; /* toprec length */
65 static char *toprec; /* Additional record specified by cgetset() */
66 static int gottoprec; /* Flag indicating retrieval of toprecord */
67
68 static int cdbget(DB *, char **, const char *);
69 static int getent(char **, u_int *, char **, int, const char *, int, char *);
70 static 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 */
77 int
78 cgetset(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 */
109 char *
110 cgetcap(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 */
160 int
161 cgetent(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 */
186 static int
187 getent(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, 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 */
390 tc_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
533 static int
534 cdbget(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 */
573 int
574 cgetmatch(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
617 int
618 cgetfirst(char **buf, char **db_array)
619 {
620 (void)cgetclose();
621 return (cgetnext(buf, db_array));
622 }
623
624 static FILE *pfp;
625 static int slash;
626 static char **dbp;
627
628 int
629 cgetclose(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 */
646 int
647 cgetnext(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, "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 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 */
783 int
784 cgetstr(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 */
910 int
911 cgetustr(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 */
978 int
979 cgetnum(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 */
1040 static int
1041 nfcmp(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 }
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