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
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.
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
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "@(#)getnetgrent.c 8.2 (Berkeley) 4/27/95";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
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 = (struct linelist *)0;
130 static struct netgrp *nextgrp = (struct netgrp *)0;
138 static FILE *netf = (FILE *)0;
140 static int parse_netgrp(const char *);
141 static struct linelist *read_for_group(const char *);
142 void setnetgrent(const char *);
143 void endnetgrent(void);
144 int getnetgrent(char **, char **, char **);
145 int innetgr(const char *, const char *, const char *, const char *);
147 #define LINSIZ 1024 /* Length of netgroup file line */
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
156 setnetgrent(const char *group)
159 struct stat _yp_statp;
165 if (group == NULL || !strlen(group))
168 if (grouphead.gr == (struct netgrp *)0 ||
169 strcmp(group, grouphead.grname)) {
172 /* Presumed guilty until proven innocent. */
175 * If /etc/netgroup doesn't exist or is empty,
176 * use NIS exclusively.
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){
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.
188 fscanf(netf, "%c", &_yp_plus);
191 _use_only_yp = _netgr_yp_enabled = 1;
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.
198 if (_use_only_yp && _yp_innetgr) {
205 if ((netf = fopen(_PATH_NETGROUP, "r"))) {
207 if (parse_netgrp(group))
210 grouphead.grname = (char *)
211 malloc(strlen(group) + 1);
212 strcpy(grouphead.grname, group);
218 nextgrp = grouphead.gr;
222 * Get the next netgroup off the list.
225 getnetgrent(char **hostp, char **userp, char **domp)
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;
242 * endnetgrent() - cleanup
247 struct linelist *lp, *olp;
248 struct netgrp *gp, *ogp;
254 free(olp->l_groupname);
258 linehead = (struct linelist *)0;
259 if (grouphead.grname) {
260 free(grouphead.grname);
261 grouphead.grname = (char *)0;
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]);
275 grouphead.gr = (struct netgrp *)0;
276 nextgrp = (struct netgrp *)0;
278 _netgr_yp_enabled = 0;
284 _listmatch(const char *list, const char *group, int len)
286 const char *ptr = list;
288 int glen = strlen(group);
290 /* skip possible leading whitespace */
291 while(isspace((unsigned char)*ptr))
294 while (ptr < list + len) {
296 while(*ptr != ',' && *ptr != '\0' && !isspace((unsigned char)*ptr))
298 if (strncmp(cptr, group, glen) == 0 && glen == (ptr - cptr))
300 while(*ptr == ',' || isspace((unsigned char)*ptr))
308 _revnetgr_lookup(char* lookupdom, char* map, const char* str,
309 const char* dom, const char* group)
312 char key[MAXHOSTNAMELEN];
316 for (rot = 0; ; rot++) {
318 case(0): snprintf(key, MAXHOSTNAMELEN, "%s.%s",
319 str, dom?dom:lookupdom);
321 case(1): snprintf(key, MAXHOSTNAMELEN, "%s.*",
324 case(2): snprintf(key, MAXHOSTNAMELEN, "*.%s",
327 case(3): snprintf(key, MAXHOSTNAMELEN, "*.*");
331 y = yp_match(lookupdom, map, key, strlen(key), &result,
334 rv = _listmatch(result, group, resultlen);
337 } else if (y != YPERR_KEY) {
339 * If we get an error other than 'no
340 * such key in map' then something is
341 * wrong and we should stop the search.
350 * Search for a match in a netgroup.
353 innetgr(const char *group, const char *host, const char *user, const char *dom)
355 char *hst, *usr, *dm;
358 if (group == NULL || !strlen(group))
368 * If we're in NIS-only mode, do the search using
369 * NIS 'reverse netgroup' lookups.
371 * What happens with 'reverse netgroup' lookups:
373 * 1) try 'reverse netgroup' lookup
374 * 1.a) if host is specified and user is null:
375 * look in netgroup.byhost
376 * (try host.domain, host.*, *.domain or *.*)
377 * if found, return yes
378 * 1.b) if user is specified and host is null:
379 * look in netgroup.byuser
380 * (try host.domain, host.*, *.domain or *.*)
381 * if found, return yes
382 * 1.c) if both host and user are specified,
383 * don't do 'reverse netgroup' lookup. It won't work.
384 * 1.d) if neither host ane user are specified (why?!?)
385 * don't do 'reverse netgroup' lookup either.
386 * 2) if domain is specified and 'reverse lookup' is done:
387 * 'reverse lookup' was authoritative. bye bye.
388 * 3) otherwise, too bad, try it the slow way.
390 if (_use_only_yp && (host == NULL) != (user == NULL)) {
392 if(yp_get_default_domain(&_netgr_yp_domain))
394 ret = _revnetgr_lookup(_netgr_yp_domain,
395 host?"netgroup.byhost":"netgroup.byuser",
396 host?host:user, dom, group);
399 else if (ret == 0 && dom != NULL)
406 while (getnetgrent(&hst, &usr, &dm))
407 if ((host == NULL || hst == NULL || !strcmp(host, hst)) &&
408 (user == NULL || usr == NULL || !strcmp(user, usr)) &&
409 ( dom == NULL || dm == NULL || !strcmp(dom, dm))) {
418 * Parse the netgroup file setting up the linked lists.
421 parse_netgrp(const char *group)
430 struct linelist *lp = linehead;
433 * First, see if the line has already been read in.
436 if (!strcmp(group, lp->l_groupname))
440 if (lp == (struct linelist *)0 &&
441 (lp = read_for_group(group)) == (struct linelist *)0)
446 * This error message is largely superflous since the
447 * code handles the error condition sucessfully, and
448 * spewing it out from inside libc can actually hose
451 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
457 /* Watch for null pointer dereferences, dammit! */
458 while (pos != NULL && *pos != '\0') {
460 grp = (struct netgrp *)malloc(sizeof (struct netgrp));
461 bzero((char *)grp, sizeof (struct netgrp));
462 grp->ng_next = grouphead.gr;
465 gpos = strsep(&pos, ")");
469 for (strpos = 0; strpos < 3; strpos++) {
470 if ((spos = strsep(&gpos, ","))) {
474 while (*spos == ' ' || *spos == '\t')
476 if ((epos = strpbrk(spos, " \t"))) {
482 grp->ng_str[strpos] = (char *)
484 bcopy(spos, grp->ng_str[strpos],
489 * All other systems I've tested
490 * return NULL for empty netgroup
491 * fields. It's up to user programs
492 * to handle the NULLs appropriately.
494 grp->ng_str[strpos] = NULL;
499 * Note: on other platforms, malformed netgroup
500 * entries are not normally flagged. While we
501 * can catch bad entries and report them, we should
502 * stay silent by default for compatibility's sake.
505 fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
506 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
507 grp->ng_str[NG_USER] == NULL ? "" : ",",
508 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
509 grp->ng_str[NG_DOM] == NULL ? "" : ",",
510 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
514 spos = strsep(&pos, ", \t");
515 if (parse_netgrp(spos))
520 while (*pos == ' ' || *pos == ',' || *pos == '\t')
527 * Read the netgroup file and save lines until the line for the netgroup
528 * is found. Return 1 if eof is encountered.
530 static struct linelist *
531 read_for_group(const char *group)
533 char *pos, *spos, *linep, *olinep;
537 char line[LINSIZ + 2];
542 while (_netgr_yp_enabled || fgets(line, LINSIZ, netf) != NULL) {
543 if (_netgr_yp_enabled) {
544 if(!_netgr_yp_domain)
545 if(yp_get_default_domain(&_netgr_yp_domain))
547 if (yp_match(_netgr_yp_domain, "netgroup", group,
548 strlen(group), &result, &resultlen)) {
551 return ((struct linelist *)0);
553 _netgr_yp_enabled = 0;
557 snprintf(line, LINSIZ, "%s %s", group, result);
561 while (fgets(line, LINSIZ, netf) != NULL) {
566 _netgr_yp_enabled = 1;
572 while (*pos == ' ' || *pos == '\t')
575 while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
579 while (*pos == ' ' || *pos == '\t')
581 if (*pos != '\n' && *pos != '\0') {
582 lp = (struct linelist *)malloc(sizeof (*lp));
584 lp->l_groupname = (char *)malloc(len + 1);
585 bcopy(spos, lp->l_groupname, len);
586 *(lp->l_groupname + len) = '\0';
591 * Loop around handling line continuations.
594 if (*(pos + len - 1) == '\n')
596 if (*(pos + len - 1) == '\\') {
602 linep = (char *)malloc(olen + len + 1);
604 bcopy(olinep, linep, olen);
607 bcopy(pos, linep + olen, len);
609 *(linep + olen) = '\0';
613 if (fgets(line, LINSIZ, netf)) {
621 lp->l_next = linehead;
625 * If this is the one we wanted, we are done.
627 if (!strcmp(lp->l_groupname, group))
633 * Yucky. The recursive nature of this whole mess might require
634 * us to make more than one pass through the netgroup file.
635 * This might be best left outside the #ifdef YP, but YP is
636 * defined by default anyway, so I'll leave it like this
637 * until I know better.
641 return ((struct linelist *)0);