source: heimdal/vendor/current/lib/roken/getcap.c

Last change on this file was 1, checked in by Paul Smedley, 10 years ago

Initial commit of Heimdal 1.5.3
File size: 25.3 KB
Line 
1/* $NetBSD: getcap.c,v 1.29 1999/03/29 09:27:29 abs Exp $ */
2
3/*-
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Casey Leedom of Lawrence Livermore National Laboratory.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <config.h>
36
37#include "roken.h"
38
39#include <sys/types.h>
40#include <ctype.h>
41#if defined(HAVE_DB_185_H)
42#include <db_185.h>
43#elif defined(HAVE_DB_H)
44#include <db.h>
45#endif
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#if 0
56#define BSIZE 1024
57#endif
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
66static size_t topreclen; /* toprec length */
67static char *toprec; /* Additional record specified by cgetset() */
68static int gottoprec; /* Flag indicating retrieval of toprecord */
69
70#if 0 /*
71 * Don't use db support unless it's build into libc but we don't
72 * check for that now, so just disable the code.
73 */
74#if defined(HAVE_DBOPEN) && defined(HAVE_DB_H)
75#define USE_DB
76#endif
77#endif
78
79#ifdef USE_DB
80static int cdbget (DB *, char **, const char *);
81#endif
82static int getent (char **, size_t *, char **, int, const char *, int, char *);
83static int nfcmp (char *, char *);
84
85
86ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetset(const char *ent);
87ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL cgetcap(char *buf, const char *cap, int type);
88ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetent(char **buf, char **db_array, const char *name);
89ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetmatch(const char *buf, const char *name);
90ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetclose(void);
91#if 0
92int cgetfirst(char **buf, char **db_array);
93int cgetnext(char **bp, char **db_array);
94#endif
95ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetstr(char *buf, const char *cap, char **str);
96ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetustr(char *buf, const char *cap, char **str);
97ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL cgetnum(char *buf, const char *cap, long *num);
98/*
99 * Cgetset() allows the addition of a user specified buffer to be added
100 * to the database array, in effect "pushing" the buffer on top of the
101 * virtual database. 0 is returned on success, -1 on failure.
102 */
103ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
104cgetset(const char *ent)
105{
106 const char *source, *check;
107 char *dest;
108
109 if (ent == NULL) {
110 if (toprec)
111 free(toprec);
112 toprec = NULL;
113 topreclen = 0;
114 return (0);
115 }
116 topreclen = strlen(ent);
117 if ((toprec = malloc (topreclen + 1)) == NULL) {
118 errno = ENOMEM;
119 return (-1);
120 }
121 gottoprec = 0;
122
123 source=ent;
124 dest=toprec;
125 while (*source) { /* Strip whitespace */
126 *dest++ = *source++; /* Do not check first field */
127 while (*source == ':') {
128 check=source+1;
129 while (*check && (isspace((unsigned char)*check) ||
130 (*check=='\\' && isspace((unsigned char)check[1]))))
131 ++check;
132 if( *check == ':' )
133 source=check;
134 else
135 break;
136
137 }
138 }
139 *dest=0;
140
141 return (0);
142}
143
144/*
145 * Cgetcap searches the capability record buf for the capability cap with
146 * type `type'. A pointer to the value of cap is returned on success, NULL
147 * if the requested capability couldn't be found.
148 *
149 * Specifying a type of ':' means that nothing should follow cap (:cap:).
150 * In this case a pointer to the terminating ':' or NUL will be returned if
151 * cap is found.
152 *
153 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
154 * return NULL.
155 */
156ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
157cgetcap(char *buf, const char *cap, int type)
158{
159 char *bp;
160 const char *cp;
161
162 bp = buf;
163 for (;;) {
164 /*
165 * Skip past the current capability field - it's either the
166 * name field if this is the first time through the loop, or
167 * the remainder of a field whose name failed to match cap.
168 */
169 for (;;)
170 if (*bp == '\0')
171 return (NULL);
172 else
173 if (*bp++ == ':')
174 break;
175
176 /*
177 * Try to match (cap, type) in buf.
178 */
179 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
180 continue;
181 if (*cp != '\0')
182 continue;
183 if (*bp == '@')
184 return (NULL);
185 if (type == ':') {
186 if (*bp != '\0' && *bp != ':')
187 continue;
188 return(bp);
189 }
190 if (*bp != type)
191 continue;
192 bp++;
193 return (*bp == '@' ? NULL : bp);
194 }
195 /* NOTREACHED */
196}
197
198/*
199 * Cgetent extracts the capability record name from the NULL terminated file
200 * array db_array and returns a pointer to a malloc'd copy of it in buf.
201 * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
202 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success,
203 * -1 if the requested record couldn't be found, -2 if a system error was
204 * encountered (couldn't open/read a file, etc.), and -3 if a potential
205 * reference loop is detected.
206 */
207ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
208cgetent(char **buf, char **db_array, const char *name)
209{
210 size_t dummy;
211
212 return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
213}
214
215/*
216 * Getent implements the functions of cgetent. If fd is non-negative,
217 * *db_array has already been opened and fd is the open file descriptor. We
218 * do this to save time and avoid using up file descriptors for tc=
219 * recursions.
220 *
221 * Getent returns the same success/failure codes as cgetent. On success, a
222 * pointer to a malloc'ed capability record with all tc= capabilities fully
223 * expanded and its length (not including trailing ASCII NUL) are left in
224 * *cap and *len.
225 *
226 * Basic algorithm:
227 * + Allocate memory incrementally as needed in chunks of size BFRAG
228 * for capability buffer.
229 * + Recurse for each tc=name and interpolate result. Stop when all
230 * names interpolated, a name can't be found, or depth exceeds
231 * MAX_RECURSION.
232 */
233static int
234getent(char **cap, size_t *len, char **db_array, int fd,
235 const char *name, int depth, char *nfield)
236{
237 char *r_end, *rp = NULL, **db_p; /* pacify gcc */
238 int myfd = 0, eof, foundit;
239 char *record;
240 int tc_not_resolved;
241
242 /*
243 * Return with ``loop detected'' error if we've recursed more than
244 * MAX_RECURSION times.
245 */
246 if (depth > MAX_RECURSION)
247 return (-3);
248
249 /*
250 * Check if we have a top record from cgetset().
251 */
252 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
253 size_t len = topreclen + BFRAG;
254 if ((record = malloc (len)) == NULL) {
255 errno = ENOMEM;
256 return (-2);
257 }
258 (void)strlcpy(record, toprec, len);
259 db_p = db_array;
260 rp = record + topreclen + 1;
261 r_end = rp + BFRAG;
262 goto tc_exp;
263 }
264 /*
265 * Allocate first chunk of memory.
266 */
267 if ((record = malloc(BFRAG)) == NULL) {
268 errno = ENOMEM;
269 return (-2);
270 }
271 r_end = record + BFRAG;
272 foundit = 0;
273 /*
274 * Loop through database array until finding the record.
275 */
276
277 for (db_p = db_array; *db_p != NULL; db_p++) {
278 eof = 0;
279
280 /*
281 * Open database if not already open.
282 */
283
284 if (fd >= 0) {
285 (void)lseek(fd, (off_t)0, SEEK_SET);
286 } else {
287#ifdef USE_DB
288 char pbuf[_POSIX_PATH_MAX];
289 char *cbuf;
290 size_t clen;
291 int retval;
292 DB *capdbp;
293
294 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
295 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
296 != NULL) {
297 free(record);
298 retval = cdbget(capdbp, &record, name);
299 if (retval < 0) {
300 /* no record available */
301 (void)capdbp->close(capdbp);
302 return (retval);
303 }
304 /* save the data; close frees it */
305 clen = strlen(record);
306 cbuf = malloc(clen + 1);
307 if (cbuf == NULL)
308 return (-2);
309 memmove(cbuf, record, clen + 1);
310 if (capdbp->close(capdbp) < 0) {
311 free(cbuf);
312 return (-2);
313 }
314 *len = clen;
315 *cap = cbuf;
316 return (retval);
317 } else
318#endif
319 {
320 fd = open(*db_p, O_RDONLY, 0);
321 if (fd < 0) {
322 /* No error on unfound file. */
323 continue;
324 }
325 myfd = 1;
326 }
327 }
328 /*
329 * Find the requested capability record ...
330 */
331 {
332 char buf[BUFSIZ];
333 char *b_end, *bp, *cp;
334 int c, slash;
335
336 /*
337 * Loop invariants:
338 * There is always room for one more character in record.
339 * R_end always points just past end of record.
340 * Rp always points just past last character in record.
341 * B_end always points just past last character in buf.
342 * Bp always points at next character in buf.
343 * Cp remembers where the last colon was.
344 */
345 b_end = buf;
346 bp = buf;
347 cp = 0;
348 slash = 0;
349 for (;;) {
350
351 /*
352 * Read in a line implementing (\, newline)
353 * line continuation.
354 */
355 rp = record;
356 for (;;) {
357 if (bp >= b_end) {
358 int n;
359
360 n = read(fd, buf, sizeof(buf));
361 if (n <= 0) {
362 if (myfd)
363 (void)close(fd);
364 if (n < 0) {
365 free(record);
366 return (-2);
367 } else {
368 fd = -1;
369 eof = 1;
370 break;
371 }
372 }
373 b_end = buf+n;
374 bp = buf;
375 }
376
377 c = *bp++;
378 if (c == '\n') {
379 if (slash) {
380 slash = 0;
381 rp--;
382 continue;
383 } else
384 break;
385 }
386 if (slash) {
387 slash = 0;
388 cp = 0;
389 }
390 if (c == ':') {
391 /*
392 * If the field was `empty' (i.e.
393 * contained only white space), back up
394 * to the colon (eliminating the
395 * field).
396 */
397 if (cp)
398 rp = cp;
399 else
400 cp = rp;
401 } else if (c == '\\') {
402 slash = 1;
403 } else if (c != ' ' && c != '\t') {
404 /*
405 * Forget where the colon was, as this
406 * is not an empty field.
407 */
408 cp = 0;
409 }
410 *rp++ = c;
411
412 /*
413 * Enforce loop invariant: if no room
414 * left in record buffer, try to get
415 * some more.
416 */
417 if (rp >= r_end) {
418 u_int pos;
419 size_t newsize;
420
421 pos = rp - record;
422 newsize = r_end - record + BFRAG;
423 record = realloc(record, newsize);
424 if (record == NULL) {
425 errno = ENOMEM;
426 if (myfd)
427 (void)close(fd);
428 return (-2);
429 }
430 r_end = record + newsize;
431 rp = record + pos;
432 }
433 }
434 /* Eliminate any white space after the last colon. */
435 if (cp)
436 rp = cp + 1;
437 /* Loop invariant lets us do this. */
438 *rp++ = '\0';
439
440 /*
441 * If encountered eof check next file.
442 */
443 if (eof)
444 break;
445
446 /*
447 * Toss blank lines and comments.
448 */
449 if (*record == '\0' || *record == '#')
450 continue;
451
452 /*
453 * See if this is the record we want ...
454 */
455 if (cgetmatch(record, name) == 0) {
456 if (nfield == NULL || !nfcmp(nfield, record)) {
457 foundit = 1;
458 break; /* found it! */
459 }
460 }
461 }
462 }
463 if (foundit)
464 break;
465 }
466
467 if (!foundit)
468 return (-1);
469
470 /*
471 * Got the capability record, but now we have to expand all tc=name
472 * references in it ...
473 */
474 tc_exp: {
475 char *newicap, *s;
476 size_t ilen, newilen;
477 int diff, iret, tclen;
478 char *icap, *scan, *tc, *tcstart, *tcend;
479
480 /*
481 * Loop invariants:
482 * There is room for one more character in record.
483 * R_end points just past end of record.
484 * Rp points just past last character in record.
485 * Scan points at remainder of record that needs to be
486 * scanned for tc=name constructs.
487 */
488 scan = record;
489 tc_not_resolved = 0;
490 for (;;) {
491 if ((tc = cgetcap(scan, "tc", '=')) == NULL)
492 break;
493
494 /*
495 * Find end of tc=name and stomp on the trailing `:'
496 * (if present) so we can use it to call ourselves.
497 */
498 s = tc;
499 for (;;)
500 if (*s == '\0')
501 break;
502 else
503 if (*s++ == ':') {
504 *(s - 1) = '\0';
505 break;
506 }
507 tcstart = tc - 3;
508 tclen = s - tcstart;
509 tcend = s;
510
511 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
512 NULL);
513 newicap = icap; /* Put into a register. */
514 newilen = ilen;
515 if (iret != 0) {
516 /* an error */
517 if (iret < -1) {
518 if (myfd)
519 (void)close(fd);
520 free(record);
521 return (iret);
522 }
523 if (iret == 1)
524 tc_not_resolved = 1;
525 /* couldn't resolve tc */
526 if (iret == -1) {
527 *(s - 1) = ':';
528 scan = s - 1;
529 tc_not_resolved = 1;
530 continue;
531
532 }
533 }
534 /* not interested in name field of tc'ed record */
535 s = newicap;
536 for (;;)
537 if (*s == '\0')
538 break;
539 else
540 if (*s++ == ':')
541 break;
542 newilen -= s - newicap;
543 newicap = s;
544
545 /* make sure interpolated record is `:'-terminated */
546 s += newilen;
547 if (*(s-1) != ':') {
548 *s = ':'; /* overwrite NUL with : */
549 newilen++;
550 }
551
552 /*
553 * Make sure there's enough room to insert the
554 * new record.
555 */
556 diff = newilen - tclen;
557 if (diff >= r_end - rp) {
558 u_int pos, tcpos, tcposend;
559 size_t newsize;
560
561 pos = rp - record;
562 newsize = r_end - record + diff + BFRAG;
563 tcpos = tcstart - record;
564 tcposend = tcend - record;
565 record = realloc(record, newsize);
566 if (record == NULL) {
567 errno = ENOMEM;
568 if (myfd)
569 (void)close(fd);
570 free(icap);
571 return (-2);
572 }
573 r_end = record + newsize;
574 rp = record + pos;
575 tcstart = record + tcpos;
576 tcend = record + tcposend;
577 }
578
579 /*
580 * Insert tc'ed record into our record.
581 */
582 s = tcstart + newilen;
583 memmove(s, tcend, (size_t)(rp - tcend));
584 memmove(tcstart, newicap, newilen);
585 rp += diff;
586 free(icap);
587
588 /*
589 * Start scan on `:' so next cgetcap works properly
590 * (cgetcap always skips first field).
591 */
592 scan = s-1;
593 }
594
595 }
596 /*
597 * Close file (if we opened it), give back any extra memory, and
598 * return capability, length and success.
599 */
600 if (myfd)
601 (void)close(fd);
602 *len = rp - record - 1; /* don't count NUL */
603 if (r_end > rp)
604 if ((record =
605 realloc(record, (size_t)(rp - record))) == NULL) {
606 errno = ENOMEM;
607 return (-2);
608 }
609
610 *cap = record;
611 if (tc_not_resolved)
612 return (1);
613 return (0);
614}
615
616#ifdef USE_DB
617static int
618cdbget(DB *capdbp, char **bp, const char *name)
619{
620 DBT key;
621 DBT data;
622
623 /* LINTED key is not modified */
624 key.data = (char *)name;
625 key.size = strlen(name);
626
627 for (;;) {
628 /* Get the reference. */
629 switch(capdbp->get(capdbp, &key, &data, 0)) {
630 case -1:
631 return (-2);
632 case 1:
633 return (-1);
634 }
635
636 /* If not an index to another record, leave. */
637 if (((char *)data.data)[0] != SHADOW)
638 break;
639
640 key.data = (char *)data.data + 1;
641 key.size = data.size - 1;
642 }
643
644 *bp = (char *)data.data + 1;
645 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
646}
647#endif /* USE_DB */
648
649/*
650 * Cgetmatch will return 0 if name is one of the names of the capability
651 * record buf, -1 if not.
652 */
653int
654cgetmatch(const char *buf, const char *name)
655{
656 const char *np, *bp;
657
658 /*
659 * Start search at beginning of record.
660 */
661 bp = buf;
662 for (;;) {
663 /*
664 * Try to match a record name.
665 */
666 np = name;
667 for (;;)
668 if (*np == '\0') {
669 if (*bp == '|' || *bp == ':' || *bp == '\0')
670 return (0);
671 else
672 break;
673 } else
674 if (*bp++ != *np++)
675 break;
676
677 /*
678 * Match failed, skip to next name in record.
679 */
680 bp--; /* a '|' or ':' may have stopped the match */
681 for (;;)
682 if (*bp == '\0' || *bp == ':')
683 return (-1); /* match failed totally */
684 else
685 if (*bp++ == '|')
686 break; /* found next name */
687 }
688}
689
690#if 0
691int
692cgetfirst(char **buf, char **db_array)
693{
694 (void)cgetclose();
695 return (cgetnext(buf, db_array));
696}
697#endif
698
699static FILE *pfp;
700static int slash;
701static char **dbp;
702
703ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
704cgetclose(void)
705{
706 if (pfp != NULL) {
707 (void)fclose(pfp);
708 pfp = NULL;
709 }
710 dbp = NULL;
711 gottoprec = 0;
712 slash = 0;
713 return(0);
714}
715
716#if 0
717/*
718 * Cgetnext() gets either the first or next entry in the logical database
719 * specified by db_array. It returns 0 upon completion of the database, 1
720 * upon returning an entry with more remaining, and -1 if an error occurs.
721 */
722int
723cgetnext(char **bp, char **db_array)
724{
725 size_t len;
726 int status, done;
727 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
728 size_t dummy;
729
730 if (dbp == NULL)
731 dbp = db_array;
732
733 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
734 (void)cgetclose();
735 return (-1);
736 }
737 for(;;) {
738 if (toprec && !gottoprec) {
739 gottoprec = 1;
740 line = toprec;
741 } else {
742 line = fgetln(pfp, &len);
743 if (line == NULL && pfp) {
744 if (ferror(pfp)) {
745 (void)cgetclose();
746 return (-1);
747 } else {
748 (void)fclose(pfp);
749 pfp = NULL;
750 if (*++dbp == NULL) {
751 (void)cgetclose();
752 return (0);
753 } else if ((pfp =
754 fopen(*dbp, "r")) == NULL) {
755 (void)cgetclose();
756 return (-1);
757 } else
758 continue;
759 }
760 } else
761 line[len - 1] = '\0';
762 if (len == 1) {
763 slash = 0;
764 continue;
765 }
766 if (isspace((unsigned char)*line) ||
767 *line == ':' || *line == '#' || slash) {
768 if (line[len - 2] == '\\')
769 slash = 1;
770 else
771 slash = 0;
772 continue;
773 }
774 if (line[len - 2] == '\\')
775 slash = 1;
776 else
777 slash = 0;
778 }
779
780
781 /*
782 * Line points to a name line.
783 */
784 done = 0;
785 np = nbuf;
786 for (;;) {
787 for (cp = line; *cp != '\0'; cp++) {
788 if (*cp == ':') {
789 *np++ = ':';
790 done = 1;
791 break;
792 }
793 if (*cp == '\\')
794 break;
795 *np++ = *cp;
796 }
797 if (done) {
798 *np = '\0';
799 break;
800 } else { /* name field extends beyond the line */
801 line = fgetln(pfp, &len);
802 if (line == NULL && pfp) {
803 if (ferror(pfp)) {
804 (void)cgetclose();
805 return (-1);
806 }
807 (void)fclose(pfp);
808 pfp = NULL;
809 *np = '\0';
810 break;
811 } else
812 line[len - 1] = '\0';
813 }
814 }
815 rp = buf;
816 for(cp = nbuf; *cp != '\0'; cp++)
817 if (*cp == '|' || *cp == ':')
818 break;
819 else
820 *rp++ = *cp;
821
822 *rp = '\0';
823 /*
824 * XXX
825 * Last argument of getent here should be nbuf if we want true
826 * sequential access in the case of duplicates.
827 * With NULL, getent will return the first entry found
828 * rather than the duplicate entry record. This is a
829 * matter of semantics that should be resolved.
830 */
831 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
832 if (status == -2 || status == -3)
833 (void)cgetclose();
834
835 return (status + 1);
836 }
837 /* NOTREACHED */
838}
839#endif
840
841/*
842 * Cgetstr retrieves the value of the string capability cap from the
843 * capability record pointed to by buf. A pointer to a decoded, NUL
844 * terminated, malloc'd copy of the string is returned in the char *
845 * pointed to by str. The length of the string not including the trailing
846 * NUL is returned on success, -1 if the requested string capability
847 * couldn't be found, -2 if a system error was encountered (storage
848 * allocation failure).
849 */
850ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
851cgetstr(char *buf, const char *cap, char **str)
852{
853 u_int m_room;
854 const char *bp;
855 char *mp;
856 int len;
857 char *mem, *nmem;
858
859 *str = NULL;
860
861 /*
862 * Find string capability cap
863 */
864 bp = cgetcap(buf, cap, '=');
865 if (bp == NULL)
866 return (-1);
867
868 /*
869 * Conversion / storage allocation loop ... Allocate memory in
870 * chunks SFRAG in size.
871 */
872 if ((mem = malloc(SFRAG)) == NULL) {
873 errno = ENOMEM;
874 return (-2); /* couldn't even allocate the first fragment */
875 }
876 m_room = SFRAG;
877 mp = mem;
878
879 while (*bp != ':' && *bp != '\0') {
880 /*
881 * Loop invariants:
882 * There is always room for one more character in mem.
883 * Mp always points just past last character in mem.
884 * Bp always points at next character in buf.
885 */
886 if (*bp == '^') {
887 bp++;
888 if (*bp == ':' || *bp == '\0')
889 break; /* drop unfinished escape */
890 *mp++ = *bp++ & 037;
891 } else if (*bp == '\\') {
892 bp++;
893 if (*bp == ':' || *bp == '\0')
894 break; /* drop unfinished escape */
895 if ('0' <= *bp && *bp <= '7') {
896 int n, i;
897
898 n = 0;
899 i = 3; /* maximum of three octal digits */
900 do {
901 n = n * 8 + (*bp++ - '0');
902 } while (--i && '0' <= *bp && *bp <= '7');
903 *mp++ = n;
904 }
905 else switch (*bp++) {
906 case 'b': case 'B':
907 *mp++ = '\b';
908 break;
909 case 't': case 'T':
910 *mp++ = '\t';
911 break;
912 case 'n': case 'N':
913 *mp++ = '\n';
914 break;
915 case 'f': case 'F':
916 *mp++ = '\f';
917 break;
918 case 'r': case 'R':
919 *mp++ = '\r';
920 break;
921 case 'e': case 'E':
922 *mp++ = ESC;
923 break;
924 case 'c': case 'C':
925 *mp++ = ':';
926 break;
927 default:
928 /*
929 * Catches '\', '^', and
930 * everything else.
931 */
932 *mp++ = *(bp-1);
933 break;
934 }
935 } else
936 *mp++ = *bp++;
937 m_room--;
938
939 /*
940 * Enforce loop invariant: if no room left in current
941 * buffer, try to get some more.
942 */
943 if (m_room == 0) {
944 size_t size = mp - mem;
945
946 if ((nmem = realloc(mem, size + SFRAG)) == NULL) {
947 free(mem);
948 return (-2);
949 }
950 mem = nmem;
951 m_room = SFRAG;
952 mp = mem + size;
953 }
954 }
955 *mp++ = '\0'; /* loop invariant let's us do this */
956 m_room--;
957 len = mp - mem - 1;
958
959 /*
960 * Give back any extra memory and return value and success.
961 */
962 if (m_room != 0) {
963 if ((nmem = realloc(mem, (size_t)(mp - mem))) == NULL) {
964 free(mem);
965 return (-2);
966 }
967 mem = nmem;
968 }
969 *str = mem;
970 return (len);
971}
972
973/*
974 * Cgetustr retrieves the value of the string capability cap from the
975 * capability record pointed to by buf. The difference between cgetustr()
976 * and cgetstr() is that cgetustr does not decode escapes but rather treats
977 * all characters literally. A pointer to a NUL terminated malloc'd
978 * copy of the string is returned in the char pointed to by str. The
979 * length of the string not including the trailing NUL is returned on success,
980 * -1 if the requested string capability couldn't be found, -2 if a system
981 * error was encountered (storage allocation failure).
982 */
983ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
984cgetustr(char *buf, const char *cap, char **str)
985{
986 u_int m_room;
987 const char *bp;
988 char *mp;
989 int len;
990 char *mem;
991
992 /*
993 * Find string capability cap
994 */
995 if ((bp = cgetcap(buf, cap, '=')) == NULL)
996 return (-1);
997
998 /*
999 * Conversion / storage allocation loop ... Allocate memory in
1000 * chunks SFRAG in size.
1001 */
1002 if ((mem = malloc(SFRAG)) == NULL) {
1003 errno = ENOMEM;
1004 return (-2); /* couldn't even allocate the first fragment */
1005 }
1006 m_room = SFRAG;
1007 mp = mem;
1008
1009 while (*bp != ':' && *bp != '\0') {
1010 /*
1011 * Loop invariants:
1012 * There is always room for one more character in mem.
1013 * Mp always points just past last character in mem.
1014 * Bp always points at next character in buf.
1015 */
1016 *mp++ = *bp++;
1017 m_room--;
1018
1019 /*
1020 * Enforce loop invariant: if no room left in current
1021 * buffer, try to get some more.
1022 */
1023 if (m_room == 0) {
1024 size_t size = mp - mem;
1025
1026 if ((mem = realloc(mem, size + SFRAG)) == NULL)
1027 return (-2);
1028 m_room = SFRAG;
1029 mp = mem + size;
1030 }
1031 }
1032 *mp++ = '\0'; /* loop invariant let's us do this */
1033 m_room--;
1034 len = mp - mem - 1;
1035
1036 /*
1037 * Give back any extra memory and return value and success.
1038 */
1039 if (m_room != 0)
1040 if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
1041 return (-2);
1042 *str = mem;
1043 return (len);
1044}
1045
1046/*
1047 * Cgetnum retrieves the value of the numeric capability cap from the
1048 * capability record pointed to by buf. The numeric value is returned in
1049 * the long pointed to by num. 0 is returned on success, -1 if the requested
1050 * numeric capability couldn't be found.
1051 */
1052ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
1053cgetnum(char *buf, const char *cap, long *num)
1054{
1055 long n;
1056 int base, digit;
1057 const char *bp;
1058
1059 /*
1060 * Find numeric capability cap
1061 */
1062 bp = cgetcap(buf, cap, '#');
1063 if (bp == NULL)
1064 return (-1);
1065
1066 /*
1067 * Look at value and determine numeric base:
1068 * 0x... or 0X... hexadecimal,
1069 * else 0... octal,
1070 * else decimal.
1071 */
1072 if (*bp == '0') {
1073 bp++;
1074 if (*bp == 'x' || *bp == 'X') {
1075 bp++;
1076 base = 16;
1077 } else
1078 base = 8;
1079 } else
1080 base = 10;
1081
1082 /*
1083 * Conversion loop ...
1084 */
1085 n = 0;
1086 for (;;) {
1087 if ('0' <= *bp && *bp <= '9')
1088 digit = *bp - '0';
1089 else if ('a' <= *bp && *bp <= 'f')
1090 digit = 10 + *bp - 'a';
1091 else if ('A' <= *bp && *bp <= 'F')
1092 digit = 10 + *bp - 'A';
1093 else
1094 break;
1095
1096 if (digit >= base)
1097 break;
1098
1099 n = n * base + digit;
1100 bp++;
1101 }
1102
1103 /*
1104 * Return value and success.
1105 */
1106 *num = n;
1107 return (0);
1108}
1109
1110
1111/*
1112 * Compare name field of record.
1113 */
1114static int
1115nfcmp(char *nf, char *rec)
1116{
1117 char *cp, tmp;
1118 int ret;
1119
1120 for (cp = rec; *cp != ':'; cp++)
1121 ;
1122
1123 tmp = *(cp + 1);
1124 *(cp + 1) = '\0';
1125 ret = strcmp(nf, rec);
1126 *(cp + 1) = tmp;
1127
1128 return (ret);
1129}
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