source: vendor/FreeBSD-libc/current/gen/getnetgrent.c

Last change on this file was 1695, checked in by bird, 21 years ago

FreeBSD 5.3 libc sources.
  • Property cvs2svn:cvs-rev set to 1.1.1.2
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 16.3 KB
Line 
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 * Rick Macklem at The University of Guelph.
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)
38static char sccsid[] = "@(#)getnetgrent.c 8.2 (Berkeley) 4/27/95";
39#endif /* LIBC_SCCS and not lint */
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: src/lib/libc/gen/getnetgrent.c,v 1.31 2004/07/28 11:56:03 des Exp $");
42
43#include <ctype.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49#ifdef YP
50/*
51 * Notes:
52 * We want to be able to use NIS netgroups properly while retaining
53 * the ability to use a local /etc/netgroup file. Unfortunately, you
54 * can't really do both at the same time - at least, not efficiently.
55 * NetBSD deals with this problem by creating a netgroup database
56 * using Berkeley DB (just like the password database) that allows
57 * for lookups using netgroup, netgroup.byuser or netgroup.byhost
58 * searches. This is a neat idea, but I don't have time to implement
59 * something like that now. (I think ultimately it would be nice
60 * if we DB-fied the group and netgroup stuff all in one shot, but
61 * for now I'm satisfied just to have something that works well
62 * without requiring massive code changes.)
63 *
64 * Therefore, to still permit the use of the local file and maintain
65 * optimum NIS performance, we allow for the following conditions:
66 *
67 * - If /etc/netgroup does not exist and NIS is turned on, we use
68 * NIS netgroups only.
69 *
70 * - If /etc/netgroup exists but is empty, we use NIS netgroups
71 * only.
72 *
73 * - If /etc/netgroup exists and contains _only_ a '+', we use
74 * NIS netgroups only.
75 *
76 * - If /etc/netgroup exists, contains locally defined netgroups
77 * and a '+', we use a mixture of NIS and the local entries.
78 * This method should return the same NIS data as just using
79 * NIS alone, but it will be slower if the NIS netgroup database
80 * is large (innetgr() in particular will suffer since extra
81 * processing has to be done in order to determine memberships
82 * using just the raw netgroup data).
83 *
84 * - If /etc/netgroup exists and contains only locally defined
85 * netgroup entries, we use just those local entries and ignore
86 * NIS (this is the original, pre-NIS behavior).
87 */
88
89#include <rpc/rpc.h>
90#include <rpcsvc/yp_prot.h>
91#include <rpcsvc/ypclnt.h>
92#include <sys/types.h>
93#include <sys/stat.h>
94#include <sys/param.h>
95#include <sys/errno.h>
96static char *_netgr_yp_domain;
97int _use_only_yp;
98static int _netgr_yp_enabled;
99static int _yp_innetgr;
100#endif
101
102#ifndef _PATH_NETGROUP
103#define _PATH_NETGROUP "/etc/netgroup"
104#endif
105
106/*
107 * Static Variables and functions used by setnetgrent(), getnetgrent() and
108 * endnetgrent().
109 * There are two linked lists:
110 * - linelist is just used by setnetgrent() to parse the net group file via.
111 * parse_netgrp()
112 * - netgrp is the list of entries for the current netgroup
113 */
114struct linelist {
115 struct linelist *l_next; /* Chain ptr. */
116 int l_parsed; /* Flag for cycles */
117 char *l_groupname; /* Name of netgroup */
118 char *l_line; /* Netgroup entrie(s) to be parsed */
119};
120
121struct netgrp {
122 struct netgrp *ng_next; /* Chain ptr */
123 char *ng_str[3]; /* Field pointers, see below */
124};
125#define NG_HOST 0 /* Host name */
126#define NG_USER 1 /* User name */
127#define NG_DOM 2 /* and Domain name */
128
129static struct linelist *linehead = (struct linelist *)0;
130static struct netgrp *nextgrp = (struct netgrp *)0;
131static struct {
132 struct netgrp *gr;
133 char *grname;
134} grouphead = {
135 (struct netgrp *)0,
136 (char *)0,
137};
138static FILE *netf = (FILE *)0;
139
140static int parse_netgrp(const char *);
141static struct linelist *read_for_group(const char *);
142void setnetgrent(const char *);
143void endnetgrent(void);
144int getnetgrent(char **, char **, char **);
145int innetgr(const char *, const char *, const char *, const char *);
146
147#define LINSIZ 1024 /* Length of netgroup file line */
148
149/*
150 * setnetgrent()
151 * Parse the netgroup file looking for the netgroup and build the list
152 * of netgrp structures. Let parse_netgrp() and read_for_group() do
153 * most of the work.
154 */
155void
156setnetgrent(const char *group)
157{
158#ifdef YP
159 struct stat _yp_statp;
160 char _yp_plus;
161#endif
162
163 /* Sanity check */
164
165 if (group == NULL || !strlen(group))
166 return;
167
168 if (grouphead.gr == (struct netgrp *)0 ||
169 strcmp(group, grouphead.grname)) {
170 endnetgrent();
171#ifdef YP
172 /* Presumed guilty until proven innocent. */
173 _use_only_yp = 0;
174 /*
175 * If /etc/netgroup doesn't exist or is empty,
176 * use NIS exclusively.
177 */
178 if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) &&
179 errno == ENOENT) || _yp_statp.st_size == 0)
180 _use_only_yp = _netgr_yp_enabled = 1;
181 if ((netf = fopen(_PATH_NETGROUP,"r")) != NULL ||_use_only_yp){
182 /*
183 * Icky: grab the first character of the netgroup file
184 * and turn on NIS if it's a '+'. rewind the stream
185 * afterwards so we don't goof up read_for_group() later.
186 */
187 if (netf) {
188 fscanf(netf, "%c", &_yp_plus);
189 rewind(netf);
190 if (_yp_plus == '+')
191 _use_only_yp = _netgr_yp_enabled = 1;
192 }
193 /*
194 * If we were called specifically for an innetgr()
195 * lookup and we're in NIS-only mode, short-circuit
196 * parse_netgroup() and cut directly to the chase.
197 */
198 if (_use_only_yp && _yp_innetgr) {
199 /* dohw! */
200 if (netf != NULL)
201 fclose(netf);
202 return;
203 }
204#else
205 if (netf = fopen(_PATH_NETGROUP, "r")) {
206#endif
207 if (parse_netgrp(group))
208 endnetgrent();
209 else {
210 grouphead.grname = (char *)
211 malloc(strlen(group) + 1);
212 strcpy(grouphead.grname, group);
213 }
214 if (netf)
215 fclose(netf);
216 }
217 }
218 nextgrp = grouphead.gr;
219}
220
221/*
222 * Get the next netgroup off the list.
223 */
224int
225getnetgrent(char **hostp, char **userp, char **domp)
226{
227#ifdef YP
228 _yp_innetgr = 0;
229#endif
230
231 if (nextgrp) {
232 *hostp = nextgrp->ng_str[NG_HOST];
233 *userp = nextgrp->ng_str[NG_USER];
234 *domp = nextgrp->ng_str[NG_DOM];
235 nextgrp = nextgrp->ng_next;
236 return (1);
237 }
238 return (0);
239}
240
241/*
242 * endnetgrent() - cleanup
243 */
244void
245endnetgrent(void)
246{
247 struct linelist *lp, *olp;
248 struct netgrp *gp, *ogp;
249
250 lp = linehead;
251 while (lp) {
252 olp = lp;
253 lp = lp->l_next;
254 free(olp->l_groupname);
255 free(olp->l_line);
256 free((char *)olp);
257 }
258 linehead = (struct linelist *)0;
259 if (grouphead.grname) {
260 free(grouphead.grname);
261 grouphead.grname = (char *)0;
262 }
263 gp = grouphead.gr;
264 while (gp) {
265 ogp = gp;
266 gp = gp->ng_next;
267 if (ogp->ng_str[NG_HOST])
268 free(ogp->ng_str[NG_HOST]);
269 if (ogp->ng_str[NG_USER])
270 free(ogp->ng_str[NG_USER]);
271 if (ogp->ng_str[NG_DOM])
272 free(ogp->ng_str[NG_DOM]);
273 free((char *)ogp);
274 }
275 grouphead.gr = (struct netgrp *)0;
276#ifdef YP
277 _netgr_yp_enabled = 0;
278#endif
279}
280
281#ifdef YP
282static int
283_listmatch(const char *list, const char *group, int len)
284{
285 const char *ptr = list;
286 const char *cptr;
287 int glen = strlen(group);
288
289 /* skip possible leading whitespace */
290 while(isspace((unsigned char)*ptr))
291 ptr++;
292
293 while (ptr < list + len) {
294 cptr = ptr;
295 while(*ptr != ',' && *ptr != '\0' && !isspace((unsigned char)*ptr))
296 ptr++;
297 if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
298 return(1);
299 while(*ptr == ',' || isspace((unsigned char)*ptr))
300 ptr++;
301 }
302
303 return(0);
304}
305
306static int
307_buildkey(char *key, const char *str, const char *dom, int *rotation)
308{
309 (*rotation)++;
310 if (*rotation > 4)
311 return(0);
312 switch(*rotation) {
313 case(1): sprintf((char *)key, "%s.%s", str, dom ? dom : "*");
314 break;
315 case(2): sprintf((char *)key, "%s.*", str);
316 break;
317 case(3): sprintf((char *)key, "*.%s", dom ? dom : "*");
318 break;
319 case(4): sprintf((char *)key, "*.*");
320 break;
321 }
322 return(1);
323}
324#endif
325
326/*
327 * Search for a match in a netgroup.
328 */
329int
330innetgr(const char *group, const char *host, const char *user, const char *dom)
331{
332 char *hst, *usr, *dm;
333#ifdef YP
334 char *result;
335 int resultlen;
336 int rv;
337#endif
338 /* Sanity check */
339
340 if (group == NULL || !strlen(group))
341 return (0);
342
343#ifdef YP
344 _yp_innetgr = 1;
345#endif
346 setnetgrent(group);
347#ifdef YP
348 _yp_innetgr = 0;
349 /*
350 * If we're in NIS-only mode, do the search using
351 * NIS 'reverse netgroup' lookups.
352 */
353 if (_use_only_yp) {
354 char _key[MAXHOSTNAMELEN];
355 int rot = 0, y = 0;
356
357 if(yp_get_default_domain(&_netgr_yp_domain))
358 return(0);
359 while(_buildkey(_key, user ? user : host, dom, &rot)) {
360 y = yp_match(_netgr_yp_domain, user? "netgroup.byuser":
361 "netgroup.byhost", _key, strlen(_key), &result,
362 &resultlen);
363 if (y) {
364 /*
365 * If we get an error other than 'no
366 * such key in map' then something is
367 * wrong and we should stop the search.
368 */
369 if (y != YPERR_KEY)
370 break;
371 } else {
372 rv = _listmatch(result, group, resultlen);
373 free(result);
374 if (rv)
375 return(1);
376 else
377 return(0);
378 }
379 }
380 /*
381 * Couldn't match using NIS-exclusive mode. If the error
382 * was YPERR_MAP, then the failure happened because there
383 * was no netgroup.byhost or netgroup.byuser map. The odds
384 * are we are talking to a Sun NIS+ server in YP emulation
385 * mode; if this is the case, then we have to do the check
386 * the 'old-fashioned' way by grovelling through the netgroup
387 * map and resolving memberships on the fly.
388 */
389 if (y != YPERR_MAP)
390 return(0);
391 }
392
393 setnetgrent(group);
394#endif /* YP */
395
396 while (getnetgrent(&hst, &usr, &dm))
397 if ((host == NULL || hst == NULL || !strcmp(host, hst)) &&
398 (user == NULL || usr == NULL || !strcmp(user, usr)) &&
399 ( dom == NULL || dm == NULL || !strcmp(dom, dm))) {
400 endnetgrent();
401 return (1);
402 }
403 endnetgrent();
404 return (0);
405}
406
407/*
408 * Parse the netgroup file setting up the linked lists.
409 */
410static int
411parse_netgrp(const char *group)
412{
413 char *spos, *epos;
414 int len, strpos;
415#ifdef DEBUG
416 int fields;
417#endif
418 char *pos, *gpos;
419 struct netgrp *grp;
420 struct linelist *lp = linehead;
421
422 /*
423 * First, see if the line has already been read in.
424 */
425 while (lp) {
426 if (!strcmp(group, lp->l_groupname))
427 break;
428 lp = lp->l_next;
429 }
430 if (lp == (struct linelist *)0 &&
431 (lp = read_for_group(group)) == (struct linelist *)0)
432 return (1);
433 if (lp->l_parsed) {
434#ifdef DEBUG
435 /*
436 * This error message is largely superflous since the
437 * code handles the error condition sucessfully, and
438 * spewing it out from inside libc can actually hose
439 * certain programs.
440 */
441 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
442#endif
443 return (1);
444 } else
445 lp->l_parsed = 1;
446 pos = lp->l_line;
447 /* Watch for null pointer dereferences, dammit! */
448 while (pos != NULL && *pos != '\0') {
449 if (*pos == '(') {
450 grp = (struct netgrp *)malloc(sizeof (struct netgrp));
451 bzero((char *)grp, sizeof (struct netgrp));
452 grp->ng_next = grouphead.gr;
453 grouphead.gr = grp;
454 pos++;
455 gpos = strsep(&pos, ")");
456#ifdef DEBUG
457 fields = 0;
458#endif
459 for (strpos = 0; strpos < 3; strpos++) {
460 if ((spos = strsep(&gpos, ","))) {
461#ifdef DEBUG
462 fields++;
463#endif
464 while (*spos == ' ' || *spos == '\t')
465 spos++;
466 if ((epos = strpbrk(spos, " \t"))) {
467 *epos = '\0';
468 len = epos - spos;
469 } else
470 len = strlen(spos);
471 if (len > 0) {
472 grp->ng_str[strpos] = (char *)
473 malloc(len + 1);
474 bcopy(spos, grp->ng_str[strpos],
475 len + 1);
476 }
477 } else {
478 /*
479 * All other systems I've tested
480 * return NULL for empty netgroup
481 * fields. It's up to user programs
482 * to handle the NULLs appropriately.
483 */
484 grp->ng_str[strpos] = NULL;
485 }
486 }
487#ifdef DEBUG
488 /*
489 * Note: on other platforms, malformed netgroup
490 * entries are not normally flagged. While we
491 * can catch bad entries and report them, we should
492 * stay silent by default for compatibility's sake.
493 */
494 if (fields < 3)
495 fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
496 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
497 grp->ng_str[NG_USER] == NULL ? "" : ",",
498 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
499 grp->ng_str[NG_DOM] == NULL ? "" : ",",
500 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
501 lp->l_groupname);
502#endif
503 } else {
504 spos = strsep(&pos, ", \t");
505 if (parse_netgrp(spos))
506 continue;
507 }
508 if (pos == NULL)
509 break;
510 while (*pos == ' ' || *pos == ',' || *pos == '\t')
511 pos++;
512 }
513 return (0);
514}
515
516/*
517 * Read the netgroup file and save lines until the line for the netgroup
518 * is found. Return 1 if eof is encountered.
519 */
520static struct linelist *
521read_for_group(const char *group)
522{
523 char *pos, *spos, *linep, *olinep;
524 int len, olen;
525 int cont;
526 struct linelist *lp;
527 char line[LINSIZ + 2];
528#ifdef YP
529 char *result;
530 int resultlen;
531
532 while (_netgr_yp_enabled || fgets(line, LINSIZ, netf) != NULL) {
533 if (_netgr_yp_enabled) {
534 if(!_netgr_yp_domain)
535 if(yp_get_default_domain(&_netgr_yp_domain))
536 continue;
537 if (yp_match(_netgr_yp_domain, "netgroup", group,
538 strlen(group), &result, &resultlen)) {
539 free(result);
540 if (_use_only_yp)
541 return ((struct linelist *)0);
542 else {
543 _netgr_yp_enabled = 0;
544 continue;
545 }
546 }
547 snprintf(line, LINSIZ, "%s %s", group, result);
548 free(result);
549 }
550#else
551 while (fgets(line, LINSIZ, netf) != NULL) {
552#endif
553 pos = (char *)&line;
554#ifdef YP
555 if (*pos == '+') {
556 _netgr_yp_enabled = 1;
557 continue;
558 }
559#endif
560 if (*pos == '#')
561 continue;
562 while (*pos == ' ' || *pos == '\t')
563 pos++;
564 spos = pos;
565 while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
566 *pos != '\0')
567 pos++;
568 len = pos - spos;
569 while (*pos == ' ' || *pos == '\t')
570 pos++;
571 if (*pos != '\n' && *pos != '\0') {
572 lp = (struct linelist *)malloc(sizeof (*lp));
573 lp->l_parsed = 0;
574 lp->l_groupname = (char *)malloc(len + 1);
575 bcopy(spos, lp->l_groupname, len);
576 *(lp->l_groupname + len) = '\0';
577 len = strlen(pos);
578 olen = 0;
579
580 /*
581 * Loop around handling line continuations.
582 */
583 do {
584 if (*(pos + len - 1) == '\n')
585 len--;
586 if (*(pos + len - 1) == '\\') {
587 len--;
588 cont = 1;
589 } else
590 cont = 0;
591 if (len > 0) {
592 linep = (char *)malloc(olen + len + 1);
593 if (olen > 0) {
594 bcopy(olinep, linep, olen);
595 free(olinep);
596 }
597 bcopy(pos, linep + olen, len);
598 olen += len;
599 *(linep + olen) = '\0';
600 olinep = linep;
601 }
602 if (cont) {
603 if (fgets(line, LINSIZ, netf)) {
604 pos = line;
605 len = strlen(pos);
606 } else
607 cont = 0;
608 }
609 } while (cont);
610 lp->l_line = linep;
611 lp->l_next = linehead;
612 linehead = lp;
613
614 /*
615 * If this is the one we wanted, we are done.
616 */
617 if (!strcmp(lp->l_groupname, group))
618 return (lp);
619 }
620 }
621#ifdef YP
622 /*
623 * Yucky. The recursive nature of this whole mess might require
624 * us to make more than one pass through the netgroup file.
625 * This might be best left outside the #ifdef YP, but YP is
626 * defined by default anyway, so I'll leave it like this
627 * until I know better.
628 */
629 rewind(netf);
630#endif
631 return ((struct linelist *)0);
632}
Note: See TracBrowser for help on using the repository browser.