2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * Rick Macklem at The University of Guelph.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
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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.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * $FreeBSD: src/lib/libc/gen/getnetgrent.c,v 1.26 1999/11/04 04:16:27 ache Exp $
37 * $DragonFly: src/lib/libcr/gen/Attic/getnetgrent.c,v 1.3 2004/07/05 17:30:59 eirikn Exp $
39 * @(#)getnetgrent.c 8.2 (Berkeley) 4/27/95
50 * We want to be able to use NIS netgroups properly while retaining
51 * the ability to use a local /etc/netgroup file. Unfortunately, you
52 * can't really do both at the same time - at least, not efficiently.
53 * NetBSD deals with this problem by creating a netgroup database
54 * using Berkeley DB (just like the password database) that allows
55 * for lookups using netgroup, netgroup.byuser or netgroup.byhost
56 * searches. This is a neat idea, but I don't have time to implement
57 * something like that now. (I think ultimately it would be nice
58 * if we DB-fied the group and netgroup stuff all in one shot, but
59 * for now I'm satisfied just to have something that works well
60 * without requiring massive code changes.)
62 * Therefore, to still permit the use of the local file and maintain
63 * optimum NIS performance, we allow for the following conditions:
65 * - If /etc/netgroup does not exist and NIS is turned on, we use
68 * - If /etc/netgroup exists but is empty, we use NIS netgroups
71 * - If /etc/netgroup exists and contains _only_ a '+', we use
74 * - If /etc/netgroup exists, contains locally defined netgroups
75 * and a '+', we use a mixture of NIS and the local entries.
76 * This method should return the same NIS data as just using
77 * NIS alone, but it will be slower if the NIS netgroup database
78 * is large (innetgr() in particular will suffer since extra
79 * processing has to be done in order to determine memberships
80 * using just the raw netgroup data).
82 * - If /etc/netgroup exists and contains only locally defined
83 * netgroup entries, we use just those local entries and ignore
84 * NIS (this is the original, pre-NIS behavior).
88 #include <rpcsvc/yp_prot.h>
89 #include <rpcsvc/ypclnt.h>
90 #include <sys/types.h>
92 #include <sys/param.h>
93 #include <sys/errno.h>
94 static char *_netgr_yp_domain;
96 static int _netgr_yp_enabled;
97 static int _yp_innetgr;
100 #ifndef _PATH_NETGROUP
101 #define _PATH_NETGROUP "/etc/netgroup"
105 * Static Variables and functions used by setnetgrent(), getnetgrent() and
107 * There are two linked lists:
108 * - linelist is just used by setnetgrent() to parse the net group file via.
110 * - netgrp is the list of entries for the current netgroup
113 struct linelist *l_next; /* Chain ptr. */
114 int l_parsed; /* Flag for cycles */
115 char *l_groupname; /* Name of netgroup */
116 char *l_line; /* Netgroup entrie(s) to be parsed */
120 struct netgrp *ng_next; /* Chain ptr */
121 char *ng_str[3]; /* Field pointers, see below */
123 #define NG_HOST 0 /* Host name */
124 #define NG_USER 1 /* User name */
125 #define NG_DOM 2 /* and Domain name */
127 static struct linelist *linehead = (struct linelist *)0;
128 static struct netgrp *nextgrp = (struct netgrp *)0;
136 static FILE *netf = (FILE *)0;
137 static int parse_netgrp();
138 static struct linelist *read_for_group();
139 void setnetgrent(), endnetgrent();
140 int getnetgrent(), innetgr();
142 #define LINSIZ 1024 /* Length of netgroup file line */
146 * Parse the netgroup file looking for the netgroup and build the list
147 * of netgrp structures. Let parse_netgrp() and read_for_group() do
155 struct stat _yp_statp;
161 if (group == NULL || !strlen(group))
164 if (grouphead.gr == (struct netgrp *)0 ||
165 strcmp(group, grouphead.grname)) {
168 /* Presumed guilty until proven innocent. */
171 * If /etc/netgroup doesn't exist or is empty,
172 * use NIS exclusively.
174 if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) &&
175 errno == ENOENT) || _yp_statp.st_size == 0)
176 _use_only_yp = _netgr_yp_enabled = 1;
177 if ((netf = fopen(_PATH_NETGROUP,"r")) != NULL ||_use_only_yp){
179 * Icky: grab the first character of the netgroup file
180 * and turn on NIS if it's a '+'. rewind the stream
181 * afterwards so we don't goof up read_for_group() later.
184 fscanf(netf, "%c", &_yp_plus);
187 _use_only_yp = _netgr_yp_enabled = 1;
190 * If we were called specifically for an innetgr()
191 * lookup and we're in NIS-only mode, short-circuit
192 * parse_netgroup() and cut directly to the chase.
194 if (_use_only_yp && _yp_innetgr) {
201 if (netf = fopen(_PATH_NETGROUP, "r")) {
203 if (parse_netgrp(group))
206 grouphead.grname = (char *)
207 malloc(strlen(group) + 1);
208 strcpy(grouphead.grname, group);
214 nextgrp = grouphead.gr;
218 * Get the next netgroup off the list.
221 getnetgrent(hostp, userp, domp)
222 char **hostp, **userp, **domp;
229 *hostp = nextgrp->ng_str[NG_HOST];
230 *userp = nextgrp->ng_str[NG_USER];
231 *domp = nextgrp->ng_str[NG_DOM];
232 nextgrp = nextgrp->ng_next;
239 * endnetgrent() - cleanup
244 struct linelist *lp, *olp;
245 struct netgrp *gp, *ogp;
251 free(olp->l_groupname);
255 linehead = (struct linelist *)0;
256 if (grouphead.grname) {
257 free(grouphead.grname);
258 grouphead.grname = (char *)0;
264 if (ogp->ng_str[NG_HOST])
265 free(ogp->ng_str[NG_HOST]);
266 if (ogp->ng_str[NG_USER])
267 free(ogp->ng_str[NG_USER]);
268 if (ogp->ng_str[NG_DOM])
269 free(ogp->ng_str[NG_DOM]);
272 grouphead.gr = (struct netgrp *)0;
274 _netgr_yp_enabled = 0;
279 static int _listmatch(list, group, len)
283 char *ptr = list, *cptr;
284 int glen = strlen(group);
286 /* skip possible leading whitespace */
287 while(isspace((unsigned char)*ptr))
290 while (ptr < list + len) {
292 while(*ptr != ',' && *ptr != '\0' && !isspace((unsigned char)*ptr))
294 if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
296 while(*ptr == ',' || isspace((unsigned char)*ptr))
303 static int _buildkey(key, str, dom, rotation)
304 char *key, *str, *dom;
311 case(1): sprintf((char *)key, "%s.%s", str, dom ? dom : "*");
313 case(2): sprintf((char *)key, "%s.*", str);
315 case(3): sprintf((char *)key, "*.%s", dom ? dom : "*");
317 case(4): sprintf((char *)key, "*.*");
325 * Search for a match in a netgroup.
328 innetgr(group, host, user, dom)
329 const char *group, *host, *user, *dom;
331 char *hst, *usr, *dm;
339 if (group == NULL || !strlen(group))
349 * If we're in NIS-only mode, do the search using
350 * NIS 'reverse netgroup' lookups.
353 char _key[MAXHOSTNAMELEN];
356 if(yp_get_default_domain(&_netgr_yp_domain))
358 while(_buildkey(_key, user ? user : host, dom, &rot)) {
359 y = yp_match(_netgr_yp_domain, user? "netgroup.byuser":
360 "netgroup.byhost", _key, strlen(_key), &result,
364 * If we get an error other than 'no
365 * such key in map' then something is
366 * wrong and we should stop the search.
371 rv = _listmatch(result, group, resultlen);
380 * Couldn't match using NIS-exclusive mode. If the error
381 * was YPERR_MAP, then the failure happened because there
382 * was no netgroup.byhost or netgroup.byuser map. The odds
383 * are we are talking to an Sun NIS+ server in YP emulation
384 * mode; if this is the case, then we have to do the check
385 * the 'old-fashioned' way by grovelling through the netgroup
386 * map and resolving memberships on the fly.
395 while (getnetgrent(&hst, &usr, &dm))
396 if ((host == NULL || hst == NULL || !strcmp(host, hst)) &&
397 (user == NULL || usr == NULL || !strcmp(user, usr)) &&
398 ( dom == NULL || dm == NULL || !strcmp(dom, dm))) {
407 * Parse the netgroup file setting up the linked lists.
420 struct linelist *lp = linehead;
423 * First, see if the line has already been read in.
426 if (!strcmp(group, lp->l_groupname))
430 if (lp == (struct linelist *)0 &&
431 (lp = read_for_group(group)) == (struct linelist *)0)
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
441 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
447 /* Watch for null pointer dereferences, dammit! */
448 while (pos != NULL && *pos != '\0') {
450 grp = (struct netgrp *)malloc(sizeof (struct netgrp));
451 bzero((char *)grp, sizeof (struct netgrp));
452 grp->ng_next = grouphead.gr;
455 gpos = strsep(&pos, ")");
459 for (strpos = 0; strpos < 3; strpos++) {
460 if ((spos = strsep(&gpos, ","))) {
464 while (*spos == ' ' || *spos == '\t')
466 if ((epos = strpbrk(spos, " \t"))) {
472 grp->ng_str[strpos] = (char *)
474 bcopy(spos, grp->ng_str[strpos],
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.
484 grp->ng_str[strpos] = NULL;
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.
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],
504 spos = strsep(&pos, ", \t");
505 if (parse_netgrp(spos))
510 while (*pos == ' ' || *pos == ',' || *pos == '\t')
517 * Read the netgroup file and save lines until the line for the netgroup
518 * is found. Return 1 if eof is encountered.
520 static struct linelist *
521 read_for_group(group)
524 char *pos, *spos, *linep, *olinep;
528 char line[LINSIZ + 2];
533 while (_netgr_yp_enabled || fgets(line, LINSIZ, netf) != NULL) {
534 if (_netgr_yp_enabled) {
535 if(!_netgr_yp_domain)
536 if(yp_get_default_domain(&_netgr_yp_domain))
538 if (yp_match(_netgr_yp_domain, "netgroup", group,
539 strlen(group), &result, &resultlen)) {
542 return ((struct linelist *)0);
544 _netgr_yp_enabled = 0;
548 snprintf(line, LINSIZ, "%s %s", group, result);
552 while (fgets(line, LINSIZ, netf) != NULL) {
557 _netgr_yp_enabled = 1;
563 while (*pos == ' ' || *pos == '\t')
566 while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
570 while (*pos == ' ' || *pos == '\t')
572 if (*pos != '\n' && *pos != '\0') {
573 lp = (struct linelist *)malloc(sizeof (*lp));
575 lp->l_groupname = (char *)malloc(len + 1);
576 bcopy(spos, lp->l_groupname, len);
577 *(lp->l_groupname + len) = '\0';
582 * Loop around handling line continuations.
585 if (*(pos + len - 1) == '\n')
587 if (*(pos + len - 1) == '\\') {
593 linep = (char *)malloc(olen + len + 1);
595 bcopy(olinep, linep, olen);
598 bcopy(pos, linep + olen, len);
600 *(linep + olen) = '\0';
604 if (fgets(line, LINSIZ, netf)) {
612 lp->l_next = linehead;
616 * If this is the one we wanted, we are done.
618 if (!strcmp(lp->l_groupname, group))
624 * Yucky. The recursive nature of this whole mess might require
625 * us to make more than one pass through the netgroup file.
626 * This might be best left outside the #ifdef YP, but YP is
627 * defined by default anyway, so I'll leave it like this
628 * until I know better.
632 return ((struct linelist *)0);