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      1 /* $OpenBSD: groupaccess.c,v 1.16 2015/05/04 06:10:48 djm Exp $ */
      2 /*
      3  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "includes.h"
     27 
     28 #include <sys/types.h>
     29 
     30 #include <grp.h>
     31 #include <unistd.h>
     32 #include <stdarg.h>
     33 #include <stdlib.h>
     34 #include <string.h>
     35 #include <limits.h>
     36 
     37 #include "xmalloc.h"
     38 #include "groupaccess.h"
     39 #include "match.h"
     40 #include "log.h"
     41 
     42 static int ngroups;
     43 static char **groups_byname;
     44 
     45 /*
     46  * Initialize group access list for user with primary (base) and
     47  * supplementary groups.  Return the number of groups in the list.
     48  */
     49 int
     50 ga_init(const char *user, gid_t base)
     51 {
     52 #if defined(ANDROID)
     53 	return 0;
     54 #else
     55 
     56 	gid_t *groups_bygid;
     57 	int i, j;
     58 	struct group *gr;
     59 
     60 	if (ngroups > 0)
     61 		ga_free();
     62 
     63 	ngroups = NGROUPS_MAX;
     64 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
     65 	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
     66 #endif
     67 
     68 	groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
     69 	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
     70 
     71 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
     72 		logit("getgrouplist: groups list too small");
     73 	for (i = 0, j = 0; i < ngroups; i++)
     74 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
     75 			groups_byname[j++] = xstrdup(gr->gr_name);
     76 	free(groups_bygid);
     77 	return (ngroups = j);
     78 #endif
     79 }
     80 
     81 /*
     82  * Return 1 if one of user's groups is contained in groups.
     83  * Return 0 otherwise.  Use match_pattern() for string comparison.
     84  */
     85 int
     86 ga_match(char * const *groups, int n)
     87 {
     88 	int i, j;
     89 
     90 	for (i = 0; i < ngroups; i++)
     91 		for (j = 0; j < n; j++)
     92 			if (match_pattern(groups_byname[i], groups[j]))
     93 				return 1;
     94 	return 0;
     95 }
     96 
     97 /*
     98  * Return 1 if one of user's groups matches group_pattern list.
     99  * Return 0 on negated or no match.
    100  */
    101 int
    102 ga_match_pattern_list(const char *group_pattern)
    103 {
    104 	int i, found = 0;
    105 
    106 	for (i = 0; i < ngroups; i++) {
    107 		switch (match_pattern_list(groups_byname[i], group_pattern, 0)) {
    108 		case -1:
    109 			return 0;	/* Negated match wins */
    110 		case 0:
    111 			continue;
    112 		case 1:
    113 			found = 1;
    114 		}
    115 	}
    116 	return found;
    117 }
    118 
    119 /*
    120  * Free memory allocated for group access list.
    121  */
    122 void
    123 ga_free(void)
    124 {
    125 	int i;
    126 
    127 	if (ngroups > 0) {
    128 		for (i = 0; i < ngroups; i++)
    129 			free(groups_byname[i]);
    130 		ngroups = 0;
    131 		free(groups_byname);
    132 	}
    133 }
    134