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.
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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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36 * $FreeBSD: src/lib/libc/gen/getnetgrent.c,v 1.26 1999/11/04 04:16:27 ache Exp $
37 * $DragonFly: src/lib/libc/gen/getnetgrent.c,v 1.5 2005/04/25 19:03:46 joerg Exp $
39 * @(#)getnetgrent.c 8.2 (Berkeley) 4/27/95
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.)
64 * Therefore, to still permit the use of the local file and maintain
65 * optimum NIS performance, we allow for the following conditions:
67 * - If /etc/netgroup does not exist and NIS is turned on, we use
70 * - If /etc/netgroup exists but is empty, we use NIS netgroups
73 * - If /etc/netgroup exists and contains _only_ a '+', we use
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).
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).
90 #include <rpcsvc/yp_prot.h>
91 #include <rpcsvc/ypclnt.h>
92 #include <sys/types.h>
94 #include <sys/param.h>
95 #include <sys/errno.h>
96 static char *_netgr_yp_domain;
98 static int _netgr_yp_enabled;
99 static int _yp_innetgr;
102 #ifndef _PATH_NETGROUP
103 #define _PATH_NETGROUP "/etc/netgroup"
107 * Static Variables and functions used by setnetgrent(), getnetgrent() and
109 * There are two linked lists:
110 * - linelist is just used by setnetgrent() to parse the net group file via.
112 * - netgrp is the list of entries for the current netgroup
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 */
122 struct netgrp *ng_next; /* Chain ptr */
123 char *ng_str[3]; /* Field pointers, see below */
125 #define NG_HOST 0 /* Host name */
126 #define NG_USER 1 /* User name */
127 #define NG_DOM 2 /* and Domain name */
129 static struct linelist *linehead = NULL;
130 static struct netgrp *nextgrp = NULL;
138 static FILE *netf = (FILE *)0;
139 static int parse_netgrp(const char *);
140 static struct linelist *read_for_group(const char *);
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
151 setnetgrent(const char *group)
154 struct stat _yp_statp;
160 if (group == NULL || !strlen(group))
163 if (grouphead.gr == (struct netgrp *)0 ||
164 strcmp(group, grouphead.grname)) {
167 /* Presumed guilty until proven innocent. */
170 * If /etc/netgroup doesn't exist or is empty,
171 * use NIS exclusively.
173 if (((stat(_PATH_NETGROUP, &_yp_statp) < 0) &&
174 errno == ENOENT) || _yp_statp.st_size == 0)
175 _use_only_yp = _netgr_yp_enabled = 1;
176 if ((netf = fopen(_PATH_NETGROUP,"r")) != NULL ||_use_only_yp){
178 * Icky: grab the first character of the netgroup file
179 * and turn on NIS if it's a '+'. rewind the stream
180 * afterwards so we don't goof up read_for_group() later.
183 fscanf(netf, "%c", &_yp_plus);
186 _use_only_yp = _netgr_yp_enabled = 1;
189 * If we were called specifically for an innetgr()
190 * lookup and we're in NIS-only mode, short-circuit
191 * parse_netgroup() and cut directly to the chase.
193 if (_use_only_yp && _yp_innetgr) {
200 if (netf = fopen(_PATH_NETGROUP, "r")) {
202 if (parse_netgrp(group))
205 grouphead.grname = (char *)
206 malloc(strlen(group) + 1);
207 strcpy(grouphead.grname, group);
213 nextgrp = grouphead.gr;
217 * Get the next netgroup off the list.
220 getnetgrent(char **hostp, char **userp, char **domp)
227 *hostp = nextgrp->ng_str[NG_HOST];
228 *userp = nextgrp->ng_str[NG_USER];
229 *domp = nextgrp->ng_str[NG_DOM];
230 nextgrp = nextgrp->ng_next;
237 * endnetgrent() - cleanup
242 struct linelist *lp, *olp;
243 struct netgrp *gp, *ogp;
249 free(olp->l_groupname);
253 linehead = (struct linelist *)0;
254 if (grouphead.grname) {
255 free(grouphead.grname);
256 grouphead.grname = (char *)0;
262 if (ogp->ng_str[NG_HOST])
263 free(ogp->ng_str[NG_HOST]);
264 if (ogp->ng_str[NG_USER])
265 free(ogp->ng_str[NG_USER]);
266 if (ogp->ng_str[NG_DOM])
267 free(ogp->ng_str[NG_DOM]);
270 grouphead.gr = (struct netgrp *)0;
272 _netgr_yp_enabled = 0;
278 _listmatch(const char *list, const char *group, int len)
280 const char *ptr = list, *cptr;
281 int glen = strlen(group);
283 /* skip possible leading whitespace */
284 while(isspace((unsigned char)*ptr))
287 while (ptr < list + len) {
289 while(*ptr != ',' && *ptr != '\0' && !isspace((unsigned char)*ptr))
291 if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
293 while(*ptr == ',' || isspace((unsigned char)*ptr))
301 _buildkey(char **key, const char *str, const char *dom, int *rotation)
310 case(1): asprintf(key, "%s.%s", str, dom ? dom : "*");
312 case(2): asprintf(key, "%s.*", str);
314 case(3): asprintf(key, "*.%s", dom ? dom : "*");
316 case(4): asprintf(key, "*.*");
326 * Search for a match in a netgroup.
329 innetgr(const char *group, const char *host, const char *user, const char *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.
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);
382 * Couldn't match using NIS-exclusive mode. If the error
383 * was YPERR_MAP, then the failure happened because there
384 * was no netgroup.byhost or netgroup.byuser map. The odds
385 * are we are talking to an Sun NIS+ server in YP emulation
386 * mode; if this is the case, then we have to do the check
387 * the 'old-fashioned' way by grovelling through the netgroup
388 * map and resolving memberships on the fly.
399 while (getnetgrent(&hst, &usr, &dm))
400 if ((host == NULL || hst == NULL || !strcmp(host, hst)) &&
401 (user == NULL || usr == NULL || !strcmp(user, usr)) &&
402 ( dom == NULL || dm == NULL || !strcmp(dom, dm))) {
411 * Parse the netgroup file setting up the linked lists.
414 parse_netgrp(const char *group)
423 struct linelist *lp = linehead;
426 * First, see if the line has already been read in.
429 if (!strcmp(group, lp->l_groupname))
433 if (lp == (struct linelist *)0 &&
434 (lp = read_for_group(group)) == (struct linelist *)0)
439 * This error message is largely superflous since the
440 * code handles the error condition successfully, and
441 * spewing it out from inside libc can actually hose
444 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
450 /* Watch for null pointer dereferences, dammit! */
451 while (pos != NULL && *pos != '\0') {
453 grp = (struct netgrp *)malloc(sizeof (struct netgrp));
454 bzero((char *)grp, sizeof (struct netgrp));
455 grp->ng_next = grouphead.gr;
458 gpos = strsep(&pos, ")");
462 for (strpos = 0; strpos < 3; strpos++) {
463 if ((spos = strsep(&gpos, ","))) {
467 while (*spos == ' ' || *spos == '\t')
469 if ((epos = strpbrk(spos, " \t"))) {
475 grp->ng_str[strpos] = (char *)
477 bcopy(spos, grp->ng_str[strpos],
482 * All other systems I've tested
483 * return NULL for empty netgroup
484 * fields. It's up to user programs
485 * to handle the NULLs appropriately.
487 grp->ng_str[strpos] = NULL;
492 * Note: on other platforms, malformed netgroup
493 * entries are not normally flagged. While we
494 * can catch bad entries and report them, we should
495 * stay silent by default for compatibility's sake.
498 fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
499 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
500 grp->ng_str[NG_USER] == NULL ? "" : ",",
501 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
502 grp->ng_str[NG_DOM] == NULL ? "" : ",",
503 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
507 spos = strsep(&pos, ", \t");
508 if (parse_netgrp(spos))
513 while (*pos == ' ' || *pos == ',' || *pos == '\t')
520 * Read the netgroup file and save lines until the line for the netgroup
521 * is found. Return 1 if eof is encountered.
523 static struct linelist *
524 read_for_group(const char *group)
526 char *pos, *spos, *linep = NULL, *olinep = NULL;
530 char line[LINSIZ + 2];
535 while (_netgr_yp_enabled || fgets(line, LINSIZ, netf) != NULL) {
536 if (_netgr_yp_enabled) {
537 if(!_netgr_yp_domain)
538 if(yp_get_default_domain(&_netgr_yp_domain))
540 if (yp_match(_netgr_yp_domain, "netgroup", group,
541 strlen(group), &result, &resultlen)) {
544 return ((struct linelist *)0);
546 _netgr_yp_enabled = 0;
550 snprintf(line, LINSIZ, "%s %s", group, result);
554 while (fgets(line, LINSIZ, netf) != NULL) {
559 _netgr_yp_enabled = 1;
565 while (*pos == ' ' || *pos == '\t')
568 while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
572 while (*pos == ' ' || *pos == '\t')
574 if (*pos != '\n' && *pos != '\0') {
575 lp = (struct linelist *)malloc(sizeof (*lp));
577 lp->l_groupname = (char *)malloc(len + 1);
578 bcopy(spos, lp->l_groupname, len);
579 *(lp->l_groupname + len) = '\0';
584 * Loop around handling line continuations.
587 if (*(pos + len - 1) == '\n')
589 if (*(pos + len - 1) == '\\') {
595 linep = (char *)malloc(olen + len + 1);
597 bcopy(olinep, linep, olen);
600 bcopy(pos, linep + olen, len);
602 *(linep + olen) = '\0';
606 if (fgets(line, LINSIZ, netf)) {
614 lp->l_next = linehead;
618 * If this is the one we wanted, we are done.
620 if (!strcmp(lp->l_groupname, group))
626 * Yucky. The recursive nature of this whole mess might require
627 * us to make more than one pass through the netgroup file.
628 * This might be best left outside the #ifdef YP, but YP is
629 * defined by default anyway, so I'll leave it like this
630 * until I know better.