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* Fix the example for configuring /etc/ttys according to the original
[dragonfly/vkernel-mp.git] / lib / libc / gen / getcap.c
blob8112b1952835ff1cb9577192bdd580e67289a575
1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Casey Leedom of Lawrence Livermore National Laboratory.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * $FreeBSD: src/lib/libc/gen/getcap.c,v 1.11.2.2 2001/01/15 06:48:09 gad Exp $
37 * $DragonFly: src/lib/libc/gen/getcap.c,v 1.7 2005/11/19 23:32:53 swildner Exp $
38 *
39 * @(#)getcap.c 8.3 (Berkeley) 3/25/94
40 */
41
42 #include "namespace.h"
43 #include <sys/types.h>
44
45 #include <ctype.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 #include "un-namespace.h"
54
55 #include <db.h>
56
57 #define BFRAG 1024
58 #define BSIZE 1024
59 #define ESC ('[' & 037) /* ASCII ESC */
60 #define MAX_RECURSION 32 /* maximum getent recursion */
61 #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */
62
63 #define RECOK (char)0
64 #define TCERR (char)1
65 #define SHADOW (char)2
66
67 static size_t topreclen; /* toprec length */
68 static char *toprec; /* Additional record specified by cgetset() */
69 static int gottoprec; /* Flag indicating retrieval of toprecord */
70
71 static int cdbget (DB *, char **, char *);
72 static int getent (char **, u_int *, char **, int, char *, int, char *);
73 static int nfcmp (char *, char *);
74
75 /*
76 * Cgetset() allows the addition of a user specified buffer to be added
77 * to the database array, in effect "pushing" the buffer on top of the
78 * virtual database. 0 is returned on success, -1 on failure.
79 */
80 int
81 cgetset(char *ent)
82 {
83 if (ent == NULL) {
84 if (toprec)
85 free(toprec);
86 toprec = NULL;
87 topreclen = 0;
88 return (0);
89 }
90 topreclen = strlen(ent);
91 if ((toprec = malloc (topreclen + 1)) == NULL) {
92 errno = ENOMEM;
93 return (-1);
94 }
95 gottoprec = 0;
96 strcpy(toprec, ent);
97 return (0);
98 }
99
100 /*
101 * Cgetcap searches the capability record buf for the capability cap with
102 * type `type'. A pointer to the value of cap is returned on success, NULL
103 * if the requested capability couldn't be found.
104 *
105 * Specifying a type of ':' means that nothing should follow cap (:cap:).
106 * In this case a pointer to the terminating ':' or NUL will be returned if
107 * cap is found.
108 *
109 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
110 * return NULL.
111 */
112 char *
113 cgetcap(char *buf, char *cap, int type)
114 {
115 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 */
162 int
163 cgetent(char **buf, char **db_array, char *name)
164 {
165 u_int dummy;
166
167 return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
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, char *name, int depth,
190 char *nfield)
191 {
192 DB *capdbp;
193 char *r_end, *rp, **db_p;
194 int myfd, eof, foundit, retval, clen;
195 char *record, *cbuf;
196 int tc_not_resolved;
197 char pbuf[_POSIX_PATH_MAX];
198
199 rp = NULL;
200 myfd = 0;
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 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 lseek(fd, (off_t)0, SEEK_SET);
246 myfd = 0;
247 } else {
248 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 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 char *b_end, *bp;
282 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 _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 _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 */
393 tc_exp: {
394 char *newicap, *s;
395 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 _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 _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 _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
536 static int
537 cdbget(DB *capdbp, char **bp, char *name)
538 {
539 DBT key, data;
540
541 key.data = name;
542 key.size = strlen(name);
543
544 for (;;) {
545 /* Get the reference. */
546 switch(capdbp->get(capdbp, &key, &data, 0)) {
547 case -1:
548 return (-2);
549 case 1:
550 return (-1);
551 }
552
553 /* If not an index to another record, leave. */
554 if (((char *)data.data)[0] != SHADOW)
555 break;
556
557 key.data = (char *)data.data + 1;
558 key.size = data.size - 1;
559 }
560
561 *bp = (char *)data.data + 1;
562 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
563 }
564
565 /*
566 * Cgetmatch will return 0 if name is one of the names of the capability
567 * record buf, -1 if not.
568 */
569 int
570 cgetmatch(char *buf, char *name)
571 {
572 char *np, *bp;
573
574 /*
575 * Start search at beginning of record.
576 */
577 bp = buf;
578 for (;;) {
579 /*
580 * Try to match a record name.
581 */
582 np = name;
583 for (;;)
584 if (*np == '\0')
585 if (*bp == '|' || *bp == ':' || *bp == '\0')
586 return (0);
587 else
588 break;
589 else
590 if (*bp++ != *np++)
591 break;
592
593 /*
594 * Match failed, skip to next name in record.
595 */
596 bp--; /* a '|' or ':' may have stopped the match */
597 for (;;)
598 if (*bp == '\0' || *bp == ':')
599 return (-1); /* match failed totally */
600 else
601 if (*bp++ == '|')
602 break; /* found next name */
603 }
604 }
605
606
607
608
609
610 int
611 cgetfirst(char **buf, char **db_array)
612 {
613 cgetclose();
614 return (cgetnext(buf, db_array));
615 }
616
617 static FILE *pfp;
618 static int slash;
619 static char **dbp;
620
621 int
622 cgetclose(void)
623 {
624 if (pfp != NULL) {
625 fclose(pfp);
626 pfp = NULL;
627 }
628 dbp = NULL;
629 gottoprec = 0;
630 slash = 0;
631 return(0);
632 }
633
634 /*
635 * Cgetnext() gets either the first or next entry in the logical database
636 * specified by db_array. It returns 0 upon completion of the database, 1
637 * upon returning an entry with more remaining, and -1 if an error occurs.
638 */
639 int
640 cgetnext(char **bp, char **db_array)
641 {
642 size_t len;
643 int done, hadreaderr, i, savederrno, status;
644 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
645 u_int dummy;
646
647 savederrno = 0;
648
649 if (dbp == NULL)
650 dbp = db_array;
651
652 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
653 cgetclose();
654 return (-1);
655 }
656 for(;;) {
657 if (toprec && !gottoprec) {
658 gottoprec = 1;
659 line = toprec;
660 } else {
661 line = fgetln(pfp, &len);
662 if (line == NULL && pfp) {
663 hadreaderr = ferror(pfp);
664 if (hadreaderr)
665 savederrno = errno;
666 fclose(pfp);
667 pfp = NULL;
668 if (hadreaderr) {
669 cgetclose();
670 errno = savederrno;
671 return (-1);
672 } else {
673 if (*++dbp == NULL) {
674 cgetclose();
675 return (0);
676 } else if ((pfp =
677 fopen(*dbp, "r")) == NULL) {
678 cgetclose();
679 return (-1);
680 } else
681 continue;
682 }
683 } else
684 line[len - 1] = '\0';
685 if (len == 1) {
686 slash = 0;
687 continue;
688 }
689 if (isspace((unsigned char)*line) ||
690 *line == ':' || *line == '#' || slash) {
691 if (line[len - 2] == '\\')
692 slash = 1;
693 else
694 slash = 0;
695 continue;
696 }
697 if (line[len - 2] == '\\')
698 slash = 1;
699 else
700 slash = 0;
701 }
702
703
704 /*
705 * Line points to a name line.
706 */
707 i = 0;
708 done = 0;
709 np = nbuf;
710 for (;;) {
711 for (cp = line; *cp != '\0'; cp++) {
712 if (*cp == ':') {
713 *np++ = ':';
714 done = 1;
715 break;
716 }
717 if (*cp == '\\')
718 break;
719 *np++ = *cp;
720 }
721 if (done) {
722 *np = '\0';
723 break;
724 } else { /* name field extends beyond the line */
725 line = fgetln(pfp, &len);
726 if (line == NULL && pfp) {
727 /* Name extends beyond the EOF! */
728 hadreaderr = ferror(pfp);
729 if (hadreaderr)
730 savederrno = errno;
731 fclose(pfp);
732 pfp = NULL;
733 if (hadreaderr) {
734 cgetclose();
735 errno = savederrno;
736 return (-1);
737 } else {
738 cgetclose();
739 return (-1);
740 }
741 } else
742 line[len - 1] = '\0';
743 }
744 }
745 rp = buf;
746 for(cp = nbuf; *cp != '\0'; cp++)
747 if (*cp == '|' || *cp == ':')
748 break;
749 else
750 *rp++ = *cp;
751
752 *rp = '\0';
753 /*
754 * XXX
755 * Last argument of getent here should be nbuf if we want true
756 * sequential access in the case of duplicates.
757 * With NULL, getent will return the first entry found
758 * rather than the duplicate entry record. This is a
759 * matter of semantics that should be resolved.
760 */
761 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
762 if (status == -2 || status == -3)
763 cgetclose();
764
765 return (status + 1);
766 }
767 /* NOTREACHED */
768 }
769
770 /*
771 * Cgetstr retrieves the value of the string capability cap from the
772 * capability record pointed to by buf. A pointer to a decoded, NUL
773 * terminated, malloc'd copy of the string is returned in the char *
774 * pointed to by str. The length of the string not including the trailing
775 * NUL is returned on success, -1 if the requested string capability
776 * couldn't be found, -2 if a system error was encountered (storage
777 * allocation failure).
778 */
779 int
780 cgetstr(char *buf, char *cap, char **str)
781 {
782 u_int m_room;
783 char *bp, *mp;
784 int len;
785 char *mem;
786
787 /*
788 * Find string capability cap
789 */
790 bp = cgetcap(buf, cap, '=');
791 if (bp == NULL)
792 return (-1);
793
794 /*
795 * Conversion / storage allocation loop ... Allocate memory in
796 * chunks SFRAG in size.
797 */
798 if ((mem = malloc(SFRAG)) == NULL) {
799 errno = ENOMEM;
800 return (-2); /* couldn't even allocate the first fragment */
801 }
802 m_room = SFRAG;
803 mp = mem;
804
805 while (*bp != ':' && *bp != '\0') {
806 /*
807 * Loop invariants:
808 * There is always room for one more character in mem.
809 * Mp always points just past last character in mem.
810 * Bp always points at next character in buf.
811 */
812 if (*bp == '^') {
813 bp++;
814 if (*bp == ':' || *bp == '\0')
815 break; /* drop unfinished escape */
816 if (*bp == '?') {
817 *mp++ = '\177';
818 bp++;
819 } else
820 *mp++ = *bp++ & 037;
821 } else if (*bp == '\\') {
822 bp++;
823 if (*bp == ':' || *bp == '\0')
824 break; /* drop unfinished escape */
825 if ('0' <= *bp && *bp <= '7') {
826 int n, i;
827
828 n = 0;
829 i = 3; /* maximum of three octal digits */
830 do {
831 n = n * 8 + (*bp++ - '0');
832 } while (--i && '0' <= *bp && *bp <= '7');
833 *mp++ = n;
834 }
835 else switch (*bp++) {
836 case 'b': case 'B':
837 *mp++ = '\b';
838 break;
839 case 't': case 'T':
840 *mp++ = '\t';
841 break;
842 case 'n': case 'N':
843 *mp++ = '\n';
844 break;
845 case 'f': case 'F':
846 *mp++ = '\f';
847 break;
848 case 'r': case 'R':
849 *mp++ = '\r';
850 break;
851 case 'e': case 'E':
852 *mp++ = ESC;
853 break;
854 case 'c': case 'C':
855 *mp++ = ':';
856 break;
857 default:
858 /*
859 * Catches '\', '^', and
860 * everything else.
861 */
862 *mp++ = *(bp-1);
863 break;
864 }
865 } else
866 *mp++ = *bp++;
867 m_room--;
868
869 /*
870 * Enforce loop invariant: if no room left in current
871 * buffer, try to get some more.
872 */
873 if (m_room == 0) {
874 size_t size = mp - mem;
875
876 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
877 return (-2);
878 m_room = SFRAG;
879 mp = mem + size;
880 }
881 }
882 *mp++ = '\0'; /* loop invariant let's us do this */
883 m_room--;
884 len = mp - mem - 1;
885
886 /*
887 * Give back any extra memory and return value and success.
888 */
889 if (m_room != 0)
890 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
891 return (-2);
892 *str = mem;
893 return (len);
894 }
895
896 /*
897 * Cgetustr retrieves the value of the string capability cap from the
898 * capability record pointed to by buf. The difference between cgetustr()
899 * and cgetstr() is that cgetustr does not decode escapes but rather treats
900 * all characters literally. A pointer to a NUL terminated malloc'd
901 * copy of the string is returned in the char pointed to by str. The
902 * length of the string not including the trailing NUL is returned on success,
903 * -1 if the requested string capability couldn't be found, -2 if a system
904 * error was encountered (storage allocation failure).
905 */
906 int
907 cgetustr(char *buf, char *cap, char **str)
908 {
909 u_int m_room;
910 char *bp, *mp;
911 int len;
912 char *mem;
913
914 /*
915 * Find string capability cap
916 */
917 if ((bp = cgetcap(buf, cap, '=')) == NULL)
918 return (-1);
919
920 /*
921 * Conversion / storage allocation loop ... Allocate memory in
922 * chunks SFRAG in size.
923 */
924 if ((mem = malloc(SFRAG)) == NULL) {
925 errno = ENOMEM;
926 return (-2); /* couldn't even allocate the first fragment */
927 }
928 m_room = SFRAG;
929 mp = mem;
930
931 while (*bp != ':' && *bp != '\0') {
932 /*
933 * Loop invariants:
934 * There is always room for one more character in mem.
935 * Mp always points just past last character in mem.
936 * Bp always points at next character in buf.
937 */
938 *mp++ = *bp++;
939 m_room--;
940
941 /*
942 * Enforce loop invariant: if no room left in current
943 * buffer, try to get some more.
944 */
945 if (m_room == 0) {
946 size_t size = mp - mem;
947
948 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
949 return (-2);
950 m_room = SFRAG;
951 mp = mem + size;
952 }
953 }
954 *mp++ = '\0'; /* loop invariant let's us do this */
955 m_room--;
956 len = mp - mem - 1;
957
958 /*
959 * Give back any extra memory and return value and success.
960 */
961 if (m_room != 0)
962 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
963 return (-2);
964 *str = mem;
965 return (len);
966 }
967
968 /*
969 * Cgetnum retrieves the value of the numeric capability cap from the
970 * capability record pointed to by buf. The numeric value is returned in
971 * the long pointed to by num. 0 is returned on success, -1 if the requested
972 * numeric capability couldn't be found.
973 */
974 int
975 cgetnum(char *buf, char *cap, long *num)
976 {
977 long n;
978 int base, digit;
979 char *bp;
980
981 /*
982 * Find numeric capability cap
983 */
984 bp = cgetcap(buf, cap, '#');
985 if (bp == NULL)
986 return (-1);
987
988 /*
989 * Look at value and determine numeric base:
990 * 0x... or 0X... hexadecimal,
991 * else 0... octal,
992 * else decimal.
993 */
994 if (*bp == '0') {
995 bp++;
996 if (*bp == 'x' || *bp == 'X') {
997 bp++;
998 base = 16;
999 } else
1000 base = 8;
1001 } else
1002 base = 10;
1003
1004 /*
1005 * Conversion loop ...
1006 */
1007 n = 0;
1008 for (;;) {
1009 if ('0' <= *bp && *bp <= '9')
1010 digit = *bp - '0';
1011 else if ('a' <= *bp && *bp <= 'f')
1012 digit = 10 + *bp - 'a';
1013 else if ('A' <= *bp && *bp <= 'F')
1014 digit = 10 + *bp - 'A';
1015 else
1016 break;
1017
1018 if (digit >= base)
1019 break;
1020
1021 n = n * base + digit;
1022 bp++;
1023 }
1024
1025 /*
1026 * Return value and success.
1027 */
1028 *num = n;
1029 return (0);
1030 }
1031
1032
1033 /*
1034 * Compare name field of record.
1035 */
1036 static int
1037 nfcmp(char *nf, char *rec)
1038 {
1039 char *cp, tmp;
1040 int ret;
1041
1042 for (cp = rec; *cp != ':'; cp++)
1043 ;
1044
1045 tmp = *(cp + 1);
1046 *(cp + 1) = '\0';
1047 ret = strcmp(nf, rec);
1048 *(cp + 1) = tmp;
1049
1050 return (ret);
1051 }
DragonFly vkernel multiprocessor port