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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 * 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 "xlocale_private.h"
40
41 #include "namespace.h"
42 #include <sys/types.h>
43
44 #include <ctype.h>
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <limits.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "un-namespace.h"
53
54 #include <db.h>
55
56 #define BFRAG 1024
57 #define BSIZE 1024
58 #define ESC ('[' & 037) /* ASCII ESC */
59 #define MAX_RECURSION 32 /* maximum getent recursion */
60 #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */
61
62 #define RECOK (char)0
63 #define TCERR (char)1
64 #define SHADOW (char)2
65
66 static size_t topreclen; /* toprec length */
67 static char *toprec; /* Additional record specified by cgetset() */
68 static int gottoprec; /* Flag indicating retrieval of toprecord */
69
70 static int cdbget(DB *, char **, const char *);
71 static int getent(char **, u_int *, char **, int, const char *, int, char *, locale_t);
72 static int nfcmp(char *, char *);
73
74 /*
75 * Cgetset() allows the addition of a user specified buffer to be added
76 * to the database array, in effect "pushing" the buffer on top of the
77 * virtual database. 0 is returned on success, -1 on failure.
78 */
79 int
80 cgetset(const 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 */
111 char *
112 cgetcap(char *buf, const char *cap, int type)
113 {
114 char *bp;
115 const char *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 */
162 int
163 cgetent(char **buf, char **db_array, const char *name)
164 {
165 u_int dummy;
166
167 return (getent(buf, &dummy, db_array, -1, name, 0, NULL, __current_locale()));
168 }
169
170 /*
171 * Getent implements the functions of cgetent. If fd is non-negative,
172 * *db_array has already been opened and fd is the open file descriptor. We
173 * do this to save time and avoid using up file descriptors for tc=
174 * recursions.
175 *
176 * Getent returns the same success/failure codes as cgetent. On success, a
177 * pointer to a malloc'ed capability record with all tc= capabilities fully
178 * expanded and its length (not including trailing ASCII NUL) are left in
179 * *cap and *len.
180 *
181 * Basic algorithm:
182 * + Allocate memory incrementally as needed in chunks of size BFRAG
183 * for capability buffer.
184 * + Recurse for each tc=name and interpolate result. Stop when all
185 * names interpolated, a name can't be found, or depth exceeds
186 * MAX_RECURSION.
187 */
188 static int
189 getent(char **cap, u_int *len, char **db_array, int fd, const char *name,
190 int depth, char *nfield, locale_t loc)
191 {
192 DB *capdbp;
193 char *r_end, *rp, **db_p;
194 int myfd, eof, foundit, retval;
195 char *record, *cbuf;
196 int tc_not_resolved;
197 char pbuf[_POSIX_PATH_MAX];
198
199 /*
200 * Return with ``loop detected'' error if we've recursed more than
201 * MAX_RECURSION times.
202 */
203 if (depth > MAX_RECURSION)
204 return (-3);
205
206 /*
207 * Check if we have a top record from cgetset().
208 */
209 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
210 if ((record = malloc (topreclen + BFRAG)) == NULL) {
211 errno = ENOMEM;
212 return (-2);
213 }
214 (void)strcpy(record, toprec);
215 myfd = 0;
216 db_p = db_array;
217 rp = record + topreclen + 1;
218 r_end = rp + BFRAG;
219 goto tc_exp;
220 }
221 /*
222 * Allocate first chunk of memory.
223 */
224 if ((record = malloc(BFRAG)) == NULL) {
225 errno = ENOMEM;
226 return (-2);
227 }
228 r_end = record + BFRAG;
229 foundit = 0;
230 /*
231 * Loop through database array until finding the record.
232 */
233
234 for (db_p = db_array; *db_p != NULL; db_p++) {
235 eof = 0;
236
237 /*
238 * Open database if not already open.
239 */
240
241 if (fd >= 0) {
242 (void)lseek(fd, (off_t)0, SEEK_SET);
243 myfd = 0;
244 } else {
245 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
246 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
247 != NULL) {
248 free(record);
249 retval = cdbget(capdbp, &record, name);
250 if (retval < 0) {
251 /* no record available */
252 (void)capdbp->close(capdbp);
253 return (retval);
254 }
255 /* save the data; close frees it */
256 cbuf = strdup(record);
257 if (capdbp->close(capdbp) < 0) {
258 free(cbuf);
259 return (-2);
260 }
261 if (cbuf == NULL) {
262 errno = ENOMEM;
263 return (-2);
264 }
265 *len = strlen(cbuf);
266 *cap = cbuf;
267 return (retval);
268 } else {
269 fd = _open(*db_p, O_RDONLY, 0);
270 if (fd < 0)
271 continue;
272 myfd = 1;
273 }
274 }
275 /*
276 * Find the requested capability record ...
277 */
278 {
279 char buf[BUFSIZ];
280 char *b_end, *bp;
281 int c;
282
283 /*
284 * Loop invariants:
285 * There is always room for one more character in record.
286 * R_end always points just past end of record.
287 * Rp always points just past last character in record.
288 * B_end always points just past last character in buf.
289 * Bp always points at next character in buf.
290 */
291 b_end = buf;
292 bp = buf;
293 for (;;) {
294
295 /*
296 * Read in a line implementing (\, newline)
297 * line continuation.
298 */
299 rp = record;
300 for (;;) {
301 if (bp >= b_end) {
302 int n;
303
304 n = _read(fd, buf, sizeof(buf));
305 if (n <= 0) {
306 if (myfd)
307 (void)_close(fd);
308 if (n < 0) {
309 free(record);
310 return (-2);
311 } else {
312 fd = -1;
313 eof = 1;
314 break;
315 }
316 }
317 b_end = buf+n;
318 bp = buf;
319 }
320
321 c = *bp++;
322 if (c == '\n') {
323 if (rp > record && *(rp-1) == '\\') {
324 rp--;
325 continue;
326 } else
327 break;
328 }
329 *rp++ = c;
330
331 /*
332 * Enforce loop invariant: if no room
333 * left in record buffer, try to get
334 * some more.
335 */
336 if (rp >= r_end) {
337 u_int pos;
338 size_t newsize;
339
340 pos = rp - record;
341 newsize = r_end - record + BFRAG;
342 record = reallocf(record, newsize);
343 if (record == NULL) {
344 errno = ENOMEM;
345 if (myfd)
346 (void)_close(fd);
347 return (-2);
348 }
349 r_end = record + newsize;
350 rp = record + pos;
351 }
352 }
353 /* loop invariant let's us do this */
354 *rp++ = '\0';
355
356 /*
357 * If encountered eof check next file.
358 */
359 if (eof)
360 break;
361
362 /*
363 * Toss blank lines and comments.
364 */
365 if (*record == '\0' || *record == '#')
366 continue;
367
368 /*
369 * See if this is the record we want ...
370 */
371 if (cgetmatch(record, name) == 0) {
372 if (nfield == NULL || !nfcmp(nfield, record)) {
373 foundit = 1;
374 break; /* found it! */
375 }
376 }
377 }
378 }
379 if (foundit)
380 break;
381 }
382
383 if (!foundit) {
384 free(record);
385 return (-1);
386 }
387
388 /*
389 * Got the capability record, but now we have to expand all tc=name
390 * references in it ...
391 */
392 tc_exp: {
393 char *newicap, *s;
394 int newilen;
395 u_int ilen;
396 int diff, iret, tclen;
397 char *icap, *scan, *tc, *tcstart, *tcend;
398
399 /*
400 * Loop invariants:
401 * There is room for one more character in record.
402 * R_end points just past end of record.
403 * Rp points just past last character in record.
404 * Scan points at remainder of record that needs to be
405 * scanned for tc=name constructs.
406 */
407 scan = record;
408 tc_not_resolved = 0;
409 for (;;) {
410 if ((tc = cgetcap(scan, "tc", '=')) == NULL)
411 break;
412
413 /*
414 * Find end of tc=name and stomp on the trailing `:'
415 * (if present) so we can use it to call ourselves.
416 */
417 s = tc;
418 for (;;)
419 if (*s == '\0')
420 break;
421 else
422 if (*s++ == ':') {
423 *(s - 1) = '\0';
424 break;
425 }
426 tcstart = tc - 3;
427 tclen = s - tcstart;
428 tcend = s;
429
430 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
431 NULL, loc);
432 newicap = icap; /* Put into a register. */
433 newilen = ilen;
434 if (iret != 0) {
435 /* an error */
436 if (iret < -1) {
437 if (myfd)
438 (void)_close(fd);
439 free(record);
440 return (iret);
441 }
442 if (iret == 1)
443 tc_not_resolved = 1;
444 /* couldn't resolve tc */
445 if (iret == -1) {
446 *(s - 1) = ':';
447 scan = s - 1;
448 tc_not_resolved = 1;
449 continue;
450
451 }
452 }
453 /* not interested in name field of tc'ed record */
454 s = newicap;
455 for (;;)
456 if (*s == '\0')
457 break;
458 else
459 if (*s++ == ':')
460 break;
461 newilen -= s - newicap;
462 newicap = s;
463
464 /* make sure interpolated record is `:'-terminated */
465 s += newilen;
466 if (*(s-1) != ':') {
467 *s = ':'; /* overwrite NUL with : */
468 newilen++;
469 }
470
471 /*
472 * Make sure there's enough room to insert the
473 * new record.
474 */
475 diff = newilen - tclen;
476 if (diff >= r_end - rp) {
477 u_int pos, tcpos, tcposend;
478 size_t newsize;
479
480 pos = rp - record;
481 newsize = r_end - record + diff + BFRAG;
482 tcpos = tcstart - record;
483 tcposend = tcend - record;
484 record = reallocf(record, newsize);
485 if (record == NULL) {
486 errno = ENOMEM;
487 if (myfd)
488 (void)_close(fd);
489 free(icap);
490 return (-2);
491 }
492 r_end = record + newsize;
493 rp = record + pos;
494 tcstart = record + tcpos;
495 tcend = record + tcposend;
496 }
497
498 /*
499 * Insert tc'ed record into our record.
500 */
501 s = tcstart + newilen;
502 bcopy(tcend, s, rp - tcend);
503 bcopy(newicap, tcstart, newilen);
504 rp += diff;
505 free(icap);
506
507 /*
508 * Start scan on `:' so next cgetcap works properly
509 * (cgetcap always skips first field).
510 */
511 scan = s-1;
512 }
513
514 }
515 /*
516 * Close file (if we opened it), give back any extra memory, and
517 * return capability, length and success.
518 */
519 if (myfd)
520 (void)_close(fd);
521 *len = rp - record - 1; /* don't count NUL */
522 if (r_end > rp)
523 if ((record =
524 reallocf(record, (size_t)(rp - record))) == NULL) {
525 errno = ENOMEM;
526 return (-2);
527 }
528
529 *cap = record;
530 if (tc_not_resolved)
531 return (1);
532 return (0);
533 }
534
535 static int
536 cdbget(DB *capdbp, char **bp, const char *name)
537 {
538 DBT key, data;
539 char *namebuf;
540
541 namebuf = strdup(name);
542 if (namebuf == NULL)
543 return (-2);
544 key.data = namebuf;
545 key.size = strlen(namebuf);
546
547 for (;;) {
548 /* Get the reference. */
549 switch(capdbp->get(capdbp, &key, &data, 0)) {
550 case -1:
551 free(namebuf);
552 return (-2);
553 case 1:
554 free(namebuf);
555 return (-1);
556 }
557
558 /* If not an index to another record, leave. */
559 if (((char *)data.data)[0] != SHADOW)
560 break;
561
562 key.data = (char *)data.data + 1;
563 key.size = data.size - 1;
564 }
565
566 *bp = (char *)data.data + 1;
567 free(namebuf);
568 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
569 }
570
571 /*
572 * Cgetmatch will return 0 if name is one of the names of the capability
573 * record buf, -1 if not.
574 */
575 int
576 cgetmatch(const char *buf, const char *name)
577 {
578 const char *np, *bp;
579
580 if (name == NULL || *name == '\0')
581 return -1;
582
583 /*
584 * Start search at beginning of record.
585 */
586 bp = buf;
587 for (;;) {
588 /*
589 * Try to match a record name.
590 */
591 np = name;
592 for (;;)
593 if (*np == '\0')
594 if (*bp == '|' || *bp == ':' || *bp == '\0')
595 return (0);
596 else
597 break;
598 else
599 if (*bp++ != *np++)
600 break;
601
602 /*
603 * Match failed, skip to next name in record.
604 */
605 bp--; /* a '|' or ':' may have stopped the match */
606 for (;;)
607 if (*bp == '\0' || *bp == ':')
608 return (-1); /* match failed totally */
609 else
610 if (*bp++ == '|')
611 break; /* found next name */
612 }
613 }
614
615
616
617
618
619 int
620 cgetfirst(char **buf, char **db_array)
621 {
622 (void)cgetclose();
623 return (cgetnext(buf, db_array));
624 }
625
626 static FILE *pfp;
627 static int slash;
628 static char **dbp;
629
630 int
631 cgetclose(void)
632 {
633 if (pfp != NULL) {
634 (void)fclose(pfp);
635 pfp = NULL;
636 }
637 dbp = NULL;
638 gottoprec = 0;
639 slash = 0;
640 return(0);
641 }
642
643 /*
644 * Cgetnext() gets either the first or next entry in the logical database
645 * specified by db_array. It returns 0 upon completion of the database, 1
646 * upon returning an entry with more remaining, and -1 if an error occurs.
647 */
648 int
649 cgetnext(char **bp, char **db_array)
650 {
651 size_t len;
652 int done, hadreaderr, savederrno, status;
653 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
654 u_int dummy;
655 locale_t loc = __current_locale();
656
657 if (dbp == NULL)
658 dbp = db_array;
659
660 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
661 (void)cgetclose();
662 return (-1);
663 }
664 for (;;) {
665 if (toprec && !gottoprec) {
666 gottoprec = 1;
667 line = toprec;
668 } else {
669 line = fgetln(pfp, &len);
670 if (line == NULL && pfp) {
671 hadreaderr = ferror(pfp);
672 if (hadreaderr)
673 savederrno = errno;
674 fclose(pfp);
675 pfp = NULL;
676 if (hadreaderr) {
677 cgetclose();
678 errno = savederrno;
679 return (-1);
680 } else {
681 if (*++dbp == NULL) {
682 (void)cgetclose();
683 return (0);
684 } else if ((pfp =
685 fopen(*dbp, "r")) == NULL) {
686 (void)cgetclose();
687 return (-1);
688 } else
689 continue;
690 }
691 } else
692 line[len - 1] = '\0';
693 if (len == 1) {
694 slash = 0;
695 continue;
696 }
697 if (isspace_l((unsigned char)*line, loc) ||
698 *line == ':' || *line == '#' || slash) {
699 if (line[len - 2] == '\\')
700 slash = 1;
701 else
702 slash = 0;
703 continue;
704 }
705 if (line[len - 2] == '\\')
706 slash = 1;
707 else
708 slash = 0;
709 }
710
711
712 /*
713 * Line points to a name line.
714 */
715 done = 0;
716 np = nbuf;
717 for (;;) {
718 for (cp = line; *cp != '\0'; cp++) {
719 if (*cp == ':') {
720 *np++ = ':';
721 done = 1;
722 break;
723 }
724 if (*cp == '\\')
725 break;
726 *np++ = *cp;
727 }
728 if (done) {
729 *np = '\0';
730 break;
731 } else { /* name field extends beyond the line */
732 line = fgetln(pfp, &len);
733 if (line == NULL && pfp) {
734 /* Name extends beyond the EOF! */
735 hadreaderr = ferror(pfp);
736 if (hadreaderr)
737 savederrno = errno;
738 fclose(pfp);
739 pfp = NULL;
740 if (hadreaderr) {
741 cgetclose();
742 errno = savederrno;
743 return (-1);
744 } else {
745 cgetclose();
746 return (-1);
747 }
748 } else
749 line[len - 1] = '\0';
750 }
751 }
752 rp = buf;
753 for(cp = nbuf; *cp != '\0'; cp++)
754 if (*cp == '|' || *cp == ':')
755 break;
756 else
757 *rp++ = *cp;
758
759 *rp = '\0';
760 /*
761 * XXX
762 * Last argument of getent here should be nbuf if we want true
763 * sequential access in the case of duplicates.
764 * With NULL, getent will return the first entry found
765 * rather than the duplicate entry record. This is a
766 * matter of semantics that should be resolved.
767 */
768 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL, loc);
769 if (status == -2 || status == -3)
770 (void)cgetclose();
771
772 return (status + 1);
773 }
774 /* NOTREACHED */
775 }
776
777 /*
778 * Cgetstr retrieves the value of the string capability cap from the
779 * capability record pointed to by buf. A pointer to a decoded, NUL
780 * terminated, malloc'd copy of the string is returned in the char *
781 * pointed to by str. The length of the string not including the trailing
782 * NUL is returned on success, -1 if the requested string capability
783 * couldn't be found, -2 if a system error was encountered (storage
784 * allocation failure).
785 */
786 int
787 cgetstr(char *buf, const char *cap, char **str)
788 {
789 u_int m_room;
790 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 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 */
913 int
914 cgetustr(char *buf, const char *cap, char **str)
915 {
916 u_int m_room;
917 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 */
981 int
982 cgetnum(char *buf, const char *cap, long *num)
983 {
984 long n;
985 int base, digit;
986 char *bp;
987
988 /*
989 * Find numeric capability cap
990 */
991 bp = cgetcap(buf, cap, '#');
992 if (bp == NULL)
993 return (-1);
994
995 /*
996 * Look at value and determine numeric base:
997 * 0x... or 0X... hexadecimal,
998 * else 0... octal,
999 * else decimal.
1000 */
1001 if (*bp == '0') {
1002 bp++;
1003 if (*bp == 'x' || *bp == 'X') {
1004 bp++;
1005 base = 16;
1006 } else
1007 base = 8;
1008 } else
1009 base = 10;
1010
1011 /*
1012 * Conversion loop ...
1013 */
1014 n = 0;
1015 for (;;) {
1016 if ('0' <= *bp && *bp <= '9')
1017 digit = *bp - '0';
1018 else if ('a' <= *bp && *bp <= 'f')
1019 digit = 10 + *bp - 'a';
1020 else if ('A' <= *bp && *bp <= 'F')
1021 digit = 10 + *bp - 'A';
1022 else
1023 break;
1024
1025 if (digit >= base)
1026 break;
1027
1028 n = n * base + digit;
1029 bp++;
1030 }
1031
1032 /*
1033 * Return value and success.
1034 */
1035 *num = n;
1036 return (0);
1037 }
1038
1039
1040 /*
1041 * Compare name field of record.
1042 */
1043 static int
1044 nfcmp(char *nf, char *rec)
1045 {
1046 char *cp, tmp;
1047 int ret;
1048
1049 for (cp = rec; *cp != ':'; cp++)
1050 ;
1051
1052 tmp = *(cp + 1);
1053 *(cp + 1) = '\0';
1054 ret = strcmp(nf, rec);
1055 *(cp + 1) = tmp;
1056
1057 return (ret);
1058 }