Annotation of src/lib/libc/gen/getcap.c, Revision 1.3
1.1 cgd 1: /*-
2: * Copyright (c) 1992 The Regents of the University of California.
3: * 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:
37: #if defined(LIBC_SCCS) && !defined(lint)
1.3 ! mycroft 38: /*static char sccsid[] = "from: @(#)getcap.c 5.15 (Berkeley) 3/19/93";*/
! 39: static char rcsid[] = "$Id: $";
1.1 cgd 40: #endif /* LIBC_SCCS and not lint */
41:
42: #include <sys/types.h>
43:
44: #include <ctype.h>
45: #include <db.h>
46: #include <errno.h>
47: #include <fcntl.h>
48: #include <limits.h>
49: #include <stdio.h>
50: #include <stdlib.h>
51: #include <string.h>
52: #include <unistd.h>
53:
54: #define BFRAG 1024
55: #define BSIZE 1024
56: #define ESC ('[' & 037) /* ASCII ESC */
57: #define MAX_RECURSION 32 /* maximum getent recursion */
58: #define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */
59:
60: #define RECOK (char)0
61: #define TCERR (char)1
62: #define SHADOW (char)2
63:
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 __P((DB *, char **, char *));
69: static int getent __P((char **, u_int *, char **, int, char *, int, char *));
70: static int nfcmp __P((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(ent)
79: char *ent;
80: {
81: if (ent == NULL) {
82: if (toprec)
83: free(toprec);
84: toprec = NULL;
85: topreclen = 0;
86: return (0);
87: }
88: topreclen = strlen(ent);
89: if ((toprec = malloc (topreclen + 1)) == NULL) {
90: errno = ENOMEM;
91: return (-1);
92: }
93: gottoprec = 0;
94: (void)strcpy(toprec, ent);
95: return (0);
96: }
97:
98: /*
99: * Cgetcap searches the capability record buf for the capability cap with
100: * type `type'. A pointer to the value of cap is returned on success, NULL
101: * if the requested capability couldn't be found.
102: *
103: * Specifying a type of ':' means that nothing should follow cap (:cap:).
104: * In this case a pointer to the terminating ':' or NUL will be returned if
105: * cap is found.
106: *
107: * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
108: * return NULL.
109: */
110: char *
111: cgetcap(buf, cap, type)
112: char *buf, *cap;
113: int type;
114: {
115: register char *bp, *cp;
116:
117: bp = buf;
118: for (;;) {
119: /*
120: * Skip past the current capability field - it's either the
121: * name field if this is the first time through the loop, or
122: * the remainder of a field whose name failed to match cap.
123: */
124: for (;;)
125: if (*bp == '\0')
126: return (NULL);
127: else
128: if (*bp++ == ':')
129: break;
130:
131: /*
132: * Try to match (cap, type) in buf.
133: */
134: for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
135: continue;
136: if (*cp != '\0')
137: continue;
138: if (*bp == '@')
139: return (NULL);
140: if (type == ':') {
141: if (*bp != '\0' && *bp != ':')
142: continue;
143: return(bp);
144: }
145: if (*bp != type)
146: continue;
147: bp++;
148: return (*bp == '@' ? NULL : bp);
149: }
150: /* NOTREACHED */
151: }
152:
153: /*
154: * Cgetent extracts the capability record name from the NULL terminated file
155: * array db_array and returns a pointer to a malloc'd copy of it in buf.
156: * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
157: * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success,
158: * -1 if the requested record couldn't be found, -2 if a system error was
159: * encountered (couldn't open/read a file, etc.), and -3 if a potential
160: * reference loop is detected.
161: */
162: int
163: cgetent(buf, db_array, name)
164: char **buf, **db_array, *name;
165: {
166: u_int dummy;
167:
168: return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
169: }
170:
171: /*
172: * Getent implements the functions of cgetent. If fd is non-negative,
173: * *db_array has already been opened and fd is the open file descriptor. We
174: * do this to save time and avoid using up file descriptors for tc=
175: * recursions.
176: *
177: * Getent returns the same success/failure codes as cgetent. On success, a
178: * pointer to a malloc'ed capability record with all tc= capabilities fully
179: * expanded and its length (not including trailing ASCII NUL) are left in
180: * *cap and *len.
181: *
182: * Basic algorithm:
183: * + Allocate memory incrementally as needed in chunks of size BFRAG
184: * for capability buffer.
185: * + Recurse for each tc=name and interpolate result. Stop when all
186: * names interpolated, a name can't be found, or depth exceeds
187: * MAX_RECURSION.
188: */
189: static int
190: getent(cap, len, db_array, fd, name, depth, nfield)
191: char **cap, **db_array, *name, *nfield;
192: u_int *len;
193: int fd, depth;
194: {
195: DB *capdbp;
196: DBT key, data;
197: register char *r_end, *rp, **db_p;
198: int myfd, eof, foundit, retval;
199: char *record;
200: int tc_not_resolved;
201: char pbuf[_POSIX_PATH_MAX];
202:
203: /*
204: * Return with ``loop detected'' error if we've recursed more than
205: * MAX_RECURSION times.
206: */
207: if (depth > MAX_RECURSION)
208: return (-3);
209:
210: /*
211: * Check if we have a top record from cgetset().
212: */
213: if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
214: if ((record = malloc (topreclen + BFRAG)) == NULL) {
215: errno = ENOMEM;
216: return (-2);
217: }
218: (void)strcpy(record, toprec);
219: myfd = 0;
220: db_p = db_array;
221: rp = record + topreclen + 1;
222: r_end = rp + BFRAG;
223: goto tc_exp;
224: }
225: /*
226: * Allocate first chunk of memory.
227: */
228: if ((record = malloc(BFRAG)) == NULL) {
229: errno = ENOMEM;
230: return (-2);
231: }
232: r_end = record + BFRAG;
233: foundit = 0;
234: /*
235: * Loop through database array until finding the record.
236: */
237:
238: for (db_p = db_array; *db_p != NULL; db_p++) {
239: eof = 0;
240:
241: /*
242: * Open database if not already open.
243: */
244:
245: if (fd >= 0) {
246: (void)lseek(fd, (off_t)0, L_SET);
247: myfd = 0;
248: } else {
249: (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
250: if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
251: != NULL) {
252: free(record);
253: retval = cdbget(capdbp, &record, name);
254: if (capdbp->close(capdbp) < 0)
255: return (-2);
256: *len = strlen(record);
257: *cap = malloc(*len + 1);
258: memmove(*cap, record, *len + 1);
259: return (retval);
260: } else {
261: fd = open(*db_p, O_RDONLY, 0);
262: if (fd < 0) {
263: /* No error on unfound file. */
264: if (errno == ENOENT)
265: continue;
266: free(record);
267: return (-2);
268: }
269: myfd = 1;
270: }
271: }
272: /*
273: * Find the requested capability record ...
274: */
275: {
276: char buf[BUFSIZ];
277: register char *b_end, *bp;
278: register int c;
279:
280: /*
281: * Loop invariants:
282: * There is always room for one more character in record.
283: * R_end always points just past end of record.
284: * Rp always points just past last character in record.
285: * B_end always points just past last character in buf.
286: * Bp always points at next character in buf.
287: */
288: b_end = buf;
289: bp = buf;
290: for (;;) {
291:
292: /*
293: * Read in a line implementing (\, newline)
294: * line continuation.
295: */
296: rp = record;
297: for (;;) {
298: if (bp >= b_end) {
299: int n;
300:
301: n = read(fd, buf, sizeof(buf));
302: if (n <= 0) {
303: if (myfd)
304: (void)close(fd);
305: if (n < 0) {
306: free(record);
307: return (-2);
308: } else {
309: fd = -1;
310: eof = 1;
311: break;
312: }
313: }
314: b_end = buf+n;
315: bp = buf;
316: }
317:
318: c = *bp++;
319: if (c == '\n') {
320: if (rp > record && *(rp-1) == '\\') {
321: rp--;
322: continue;
323: } else
324: break;
325: }
326: *rp++ = c;
327:
328: /*
329: * Enforce loop invariant: if no room
330: * left in record buffer, try to get
331: * some more.
332: */
333: if (rp >= r_end) {
334: u_int pos;
335: size_t newsize;
336:
337: pos = rp - record;
338: newsize = r_end - record + BFRAG;
339: record = realloc(record, newsize);
340: if (record == NULL) {
341: errno = ENOMEM;
342: if (myfd)
343: (void)close(fd);
344: return (-2);
345: }
346: r_end = record + newsize;
347: rp = record + pos;
348: }
349: }
350: /* loop invariant let's us do this */
351: *rp++ = '\0';
352:
353: /*
354: * If encountered eof check next file.
355: */
356: if (eof)
357: break;
358:
359: /*
360: * Toss blank lines and comments.
361: */
362: if (*record == '\0' || *record == '#')
363: continue;
364:
365: /*
366: * See if this is the record we want ...
367: */
368: if (cgetmatch(record, name) == 0) {
369: if (nfield == NULL || !nfcmp(nfield, record)) {
370: foundit = 1;
371: break; /* found it! */
372: }
373: }
374: }
375: }
376: if (foundit)
377: break;
378: }
379:
380: if (!foundit)
381: return (-1);
382:
383: /*
384: * Got the capability record, but now we have to expand all tc=name
385: * references in it ...
386: */
387: tc_exp: {
388: register char *newicap, *s;
389: register int newilen;
390: u_int ilen;
391: int diff, iret, tclen;
392: char *icap, *scan, *tc, *tcstart, *tcend;
393:
394: /*
395: * Loop invariants:
396: * There is room for one more character in record.
397: * R_end points just past end of record.
398: * Rp points just past last character in record.
399: * Scan points at remainder of record that needs to be
400: * scanned for tc=name constructs.
401: */
402: scan = record;
403: tc_not_resolved = 0;
404: for (;;) {
405: if ((tc = cgetcap(scan, "tc", '=')) == NULL)
406: break;
407:
408: /*
409: * Find end of tc=name and stomp on the trailing `:'
410: * (if present) so we can use it to call ourselves.
411: */
412: s = tc;
413: for (;;)
414: if (*s == '\0')
415: break;
416: else
417: if (*s++ == ':') {
418: *(s - 1) = '\0';
419: break;
420: }
421: tcstart = tc - 3;
422: tclen = s - tcstart;
423: tcend = s;
424:
425: iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
426: NULL);
427: newicap = icap; /* Put into a register. */
428: newilen = ilen;
429: if (iret != 0) {
430: /* an error */
431: if (iret < -1) {
432: if (myfd)
433: (void)close(fd);
434: free(record);
435: return (iret);
436: }
437: if (iret == 1)
438: tc_not_resolved = 1;
439: /* couldn't resolve tc */
440: if (iret == -1) {
441: *(s - 1) = ':';
442: scan = s - 1;
443: tc_not_resolved = 1;
444: continue;
445:
446: }
447: }
448: /* not interested in name field of tc'ed record */
449: s = newicap;
450: for (;;)
451: if (*s == '\0')
452: break;
453: else
454: if (*s++ == ':')
455: break;
456: newilen -= s - newicap;
457: newicap = s;
458:
459: /* make sure interpolated record is `:'-terminated */
460: s += newilen;
461: if (*(s-1) != ':') {
462: *s = ':'; /* overwrite NUL with : */
463: newilen++;
464: }
465:
466: /*
467: * Make sure there's enough room to insert the
468: * new record.
469: */
470: diff = newilen - tclen;
471: if (diff >= r_end - rp) {
472: u_int pos, tcpos, tcposend;
473: size_t newsize;
474:
475: pos = rp - record;
476: newsize = r_end - record + diff + BFRAG;
477: tcpos = tcstart - record;
478: tcposend = tcend - record;
479: record = realloc(record, newsize);
480: if (record == NULL) {
481: errno = ENOMEM;
482: if (myfd)
483: (void)close(fd);
484: free(icap);
485: return (-2);
486: }
487: r_end = record + newsize;
488: rp = record + pos;
489: tcstart = record + tcpos;
490: tcend = record + tcposend;
491: }
492:
493: /*
494: * Insert tc'ed record into our record.
495: */
496: s = tcstart + newilen;
497: bcopy(tcend, s, rp - tcend);
498: bcopy(newicap, tcstart, newilen);
499: rp += diff;
500: free(icap);
501:
502: /*
503: * Start scan on `:' so next cgetcap works properly
504: * (cgetcap always skips first field).
505: */
506: scan = s-1;
507: }
508:
509: }
510: /*
511: * Close file (if we opened it), give back any extra memory, and
512: * return capability, length and success.
513: */
514: if (myfd)
515: (void)close(fd);
516: *len = rp - record - 1; /* don't count NUL */
517: if (r_end > rp)
518: if ((record =
519: realloc(record, (size_t)(rp - record))) == NULL) {
520: errno = ENOMEM;
521: return (-2);
522: }
523:
524: *cap = record;
525: if (tc_not_resolved)
526: return (1);
527: return (0);
528: }
529:
530: static int
531: cdbget(capdbp, bp, name)
532: DB *capdbp;
533: char **bp, *name;
534: {
535: DBT key, data;
536: char *buf;
537: int st;
538:
539: key.data = name;
540: key.size = strlen(name);
541:
542: for (;;) {
543: /* Get the reference. */
544: switch(capdbp->get(capdbp, &key, &data, 0)) {
545: case -1:
546: return (-2);
547: case 1:
548: return (-1);
549: }
550:
551: /* If not an index to another record, leave. */
552: if (((char *)data.data)[0] != SHADOW)
553: break;
554:
555: key.data = (char *)data.data + 1;
556: key.size = data.size - 1;
557: }
558:
559: *bp = (char *)data.data + 1;
560: return (((char *)(data.data))[0] == TCERR ? 1 : 0);
561: }
562:
563: /*
564: * Cgetmatch will return 0 if name is one of the names of the capability
565: * record buf, -1 if not.
566: */
567: int
568: cgetmatch(buf, name)
569: char *buf, *name;
570: {
571: register char *np, *bp;
572:
573: /*
574: * Start search at beginning of record.
575: */
576: bp = buf;
577: for (;;) {
578: /*
579: * Try to match a record name.
580: */
581: np = name;
582: for (;;)
583: if (*np == '\0')
584: if (*bp == '|' || *bp == ':' || *bp == '\0')
585: return (0);
586: else
587: break;
588: else
589: if (*bp++ != *np++)
590: break;
591:
592: /*
593: * Match failed, skip to next name in record.
594: */
595: bp--; /* a '|' or ':' may have stopped the match */
596: for (;;)
597: if (*bp == '\0' || *bp == ':')
598: return (-1); /* match failed totally */
599: else
600: if (*bp++ == '|')
601: break; /* found next name */
602: }
603: }
604:
605:
606:
607:
608:
609: int
610: cgetfirst(buf, db_array)
611: char **buf, **db_array;
612: {
613: (void)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()
623: {
624: if (pfp != NULL) {
625: (void)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(bp, db_array)
641: register char **bp;
642: char **db_array;
643: {
644: size_t len;
645: int status, i, done;
646: char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
647: u_int dummy;
648:
649: if (dbp == NULL)
650: dbp = db_array;
651:
652: if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
653: (void)cgetclose();
654: return (-1);
655: }
656: for(;;) {
657: if (toprec && !gottoprec) {
658: gottoprec = 1;
659: line = toprec;
660: } else {
661: line = fgetline(pfp, &len);
662: if (line == NULL && pfp) {
663: (void)fclose(pfp);
664: if (ferror(pfp)) {
665: (void)cgetclose();
666: return (-1);
667: } else {
668: if (*++dbp == NULL) {
669: (void)cgetclose();
670: return (0);
671: } else if ((pfp =
672: fopen(*dbp, "r")) == NULL) {
673: (void)cgetclose();
674: return (-1);
675: } else
676: continue;
677: }
1.2 mycroft 678: }
679: if (len == 0) {
1.1 cgd 680: slash = 0;
681: continue;
682: }
683: if (isspace(*line) ||
684: *line == ':' || *line == '#' || slash) {
1.2 mycroft 685: if (line[len - 1] == '\\')
1.1 cgd 686: slash = 1;
687: else
688: slash = 0;
689: continue;
690: }
1.2 mycroft 691: if (line[len - 1] == '\\')
1.1 cgd 692: slash = 1;
693: else
694: slash = 0;
695: }
696:
697:
698: /*
699: * Line points to a name line.
700: */
701: i = 0;
702: done = 0;
703: np = nbuf;
704: for (;;) {
705: for (cp = line; *cp != '\0'; cp++) {
706: if (*cp == ':') {
707: *np++ = ':';
708: done = 1;
709: break;
710: }
711: if (*cp == '\\')
712: break;
713: *np++ = *cp;
714: }
715: if (done) {
716: *np = '\0';
717: break;
718: } else { /* name field extends beyond the line */
719: line = fgetline(pfp, &len);
720: if (line == NULL && pfp) {
721: (void)fclose(pfp);
722: if (ferror(pfp)) {
723: (void)cgetclose();
724: return (-1);
725: }
1.2 mycroft 726: }
1.1 cgd 727: }
728: }
729: rp = buf;
730: for(cp = nbuf; *cp != NULL; cp++)
731: if (*cp == '|' || *cp == ':')
732: break;
733: else
734: *rp++ = *cp;
735:
736: *rp = '\0';
737: /*
738: * XXX
739: * Last argument of getent here should be nbuf if we want true
740: * sequential access in the case of duplicates.
741: * With NULL, getent will return the first entry found
742: * rather than the duplicate entry record. This is a
743: * matter of semantics that should be resolved.
744: */
745: status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
746: if (status == -2 || status == -3)
747: (void)cgetclose();
748:
749: return (status + 1);
750: }
751: /* NOTREACHED */
752: }
753:
754: /*
755: * Cgetstr retrieves the value of the string capability cap from the
756: * capability record pointed to by buf. A pointer to a decoded, NUL
757: * terminated, malloc'd copy of the string is returned in the char *
758: * pointed to by str. The length of the string not including the trailing
759: * NUL is returned on success, -1 if the requested string capability
760: * couldn't be found, -2 if a system error was encountered (storage
761: * allocation failure).
762: */
763: int
764: cgetstr(buf, cap, str)
765: char *buf, *cap;
766: char **str;
767: {
768: register u_int m_room;
769: register char *bp, *mp;
770: int len;
771: char *mem;
772:
773: /*
774: * Find string capability cap
775: */
776: bp = cgetcap(buf, cap, '=');
777: if (bp == NULL)
778: return (-1);
779:
780: /*
781: * Conversion / storage allocation loop ... Allocate memory in
782: * chunks SFRAG in size.
783: */
784: if ((mem = malloc(SFRAG)) == NULL) {
785: errno = ENOMEM;
786: return (-2); /* couldn't even allocate the first fragment */
787: }
788: m_room = SFRAG;
789: mp = mem;
790:
791: while (*bp != ':' && *bp != '\0') {
792: /*
793: * Loop invariants:
794: * There is always room for one more character in mem.
795: * Mp always points just past last character in mem.
796: * Bp always points at next character in buf.
797: */
798: if (*bp == '^') {
799: bp++;
800: if (*bp == ':' || *bp == '\0')
801: break; /* drop unfinished escape */
802: *mp++ = *bp++ & 037;
803: } else if (*bp == '\\') {
804: bp++;
805: if (*bp == ':' || *bp == '\0')
806: break; /* drop unfinished escape */
807: if ('0' <= *bp && *bp <= '7') {
808: register int n, i;
809:
810: n = 0;
811: i = 3; /* maximum of three octal digits */
812: do {
813: n = n * 8 + (*bp++ - '0');
814: } while (--i && '0' <= *bp && *bp <= '7');
815: *mp++ = n;
816: }
817: else switch (*bp++) {
818: case 'b': case 'B':
819: *mp++ = '\b';
820: break;
821: case 't': case 'T':
822: *mp++ = '\t';
823: break;
824: case 'n': case 'N':
825: *mp++ = '\n';
826: break;
827: case 'f': case 'F':
828: *mp++ = '\f';
829: break;
830: case 'r': case 'R':
831: *mp++ = '\r';
832: break;
833: case 'e': case 'E':
834: *mp++ = ESC;
835: break;
836: case 'c': case 'C':
837: *mp++ = ':';
838: break;
839: default:
840: /*
841: * Catches '\', '^', and
842: * everything else.
843: */
844: *mp++ = *(bp-1);
845: break;
846: }
847: } else
848: *mp++ = *bp++;
849: m_room--;
850:
851: /*
852: * Enforce loop invariant: if no room left in current
853: * buffer, try to get some more.
854: */
855: if (m_room == 0) {
856: size_t size = mp - mem;
857:
858: if ((mem = realloc(mem, size + SFRAG)) == NULL)
859: return (-2);
860: m_room = SFRAG;
861: mp = mem + size;
862: }
863: }
864: *mp++ = '\0'; /* loop invariant let's us do this */
865: m_room--;
866: len = mp - mem - 1;
867:
868: /*
869: * Give back any extra memory and return value and success.
870: */
871: if (m_room != 0)
872: if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
873: return (-2);
874: *str = mem;
875: return (len);
876: }
877:
878: /*
879: * Cgetustr retrieves the value of the string capability cap from the
880: * capability record pointed to by buf. The difference between cgetustr()
881: * and cgetstr() is that cgetustr does not decode escapes but rather treats
882: * all characters literally. A pointer to a NUL terminated malloc'd
883: * copy of the string is returned in the char pointed to by str. The
884: * length of the string not including the trailing NUL is returned on success,
885: * -1 if the requested string capability couldn't be found, -2 if a system
886: * error was encountered (storage allocation failure).
887: */
888: int
889: cgetustr(buf, cap, str)
890: char *buf, *cap, **str;
891: {
892: register u_int m_room;
893: register char *bp, *mp;
894: int len;
895: char *mem;
896:
897: /*
898: * Find string capability cap
899: */
900: if ((bp = cgetcap(buf, cap, '=')) == NULL)
901: return (-1);
902:
903: /*
904: * Conversion / storage allocation loop ... Allocate memory in
905: * chunks SFRAG in size.
906: */
907: if ((mem = malloc(SFRAG)) == NULL) {
908: errno = ENOMEM;
909: return (-2); /* couldn't even allocate the first fragment */
910: }
911: m_room = SFRAG;
912: mp = mem;
913:
914: while (*bp != ':' && *bp != '\0') {
915: /*
916: * Loop invariants:
917: * There is always room for one more character in mem.
918: * Mp always points just past last character in mem.
919: * Bp always points at next character in buf.
920: */
921: *mp++ = *bp++;
922: m_room--;
923:
924: /*
925: * Enforce loop invariant: if no room left in current
926: * buffer, try to get some more.
927: */
928: if (m_room == 0) {
929: size_t size = mp - mem;
930:
931: if ((mem = realloc(mem, size + SFRAG)) == NULL)
932: return (-2);
933: m_room = SFRAG;
934: mp = mem + size;
935: }
936: }
937: *mp++ = '\0'; /* loop invariant let's us do this */
938: m_room--;
939: len = mp - mem - 1;
940:
941: /*
942: * Give back any extra memory and return value and success.
943: */
944: if (m_room != 0)
945: if ((mem = realloc(mem, (size_t)(mp - mem))) == NULL)
946: return (-2);
947: *str = mem;
948: return (len);
949: }
950:
951: /*
952: * Cgetnum retrieves the value of the numeric capability cap from the
953: * capability record pointed to by buf. The numeric value is returned in
954: * the long pointed to by num. 0 is returned on success, -1 if the requested
955: * numeric capability couldn't be found.
956: */
957: int
958: cgetnum(buf, cap, num)
959: char *buf, *cap;
960: long *num;
961: {
962: register long n;
963: register int base, digit;
964: register char *bp;
965:
966: /*
967: * Find numeric capability cap
968: */
969: bp = cgetcap(buf, cap, '#');
970: if (bp == NULL)
971: return (-1);
972:
973: /*
974: * Look at value and determine numeric base:
975: * 0x... or 0X... hexadecimal,
976: * else 0... octal,
977: * else decimal.
978: */
979: if (*bp == '0') {
980: bp++;
981: if (*bp == 'x' || *bp == 'X') {
982: bp++;
983: base = 16;
984: } else
985: base = 8;
986: } else
987: base = 10;
988:
989: /*
990: * Conversion loop ...
991: */
992: n = 0;
993: for (;;) {
994: if ('0' <= *bp && *bp <= '9')
995: digit = *bp - '0';
996: else if ('a' <= *bp && *bp <= 'f')
997: digit = 10 + *bp - 'a';
998: else if ('A' <= *bp && *bp <= 'F')
999: digit = 10 + *bp - 'A';
1000: else
1001: break;
1002:
1003: if (digit >= base)
1004: break;
1005:
1006: n = n * base + digit;
1007: bp++;
1008: }
1009:
1010: /*
1011: * Return value and success.
1012: */
1013: *num = n;
1014: return (0);
1015: }
1016:
1017:
1018: /*
1019: * Compare name field of record.
1020: */
1021: static int
1022: nfcmp(nf, rec)
1023: char *nf, *rec;
1024: {
1025: char *cp, tmp;
1026: int ret;
1027:
1028: for (cp = rec; *cp != ':'; cp++)
1029: ;
1030:
1031: tmp = *(cp + 1);
1032: *(cp + 1) = '\0';
1033: ret = strcmp(nf, rec);
1034: *(cp + 1) = tmp;
1035:
1036: return (ret);
1037: }
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