1 /* $NetBSD: getgrouplist.c,v 1.17 2003/08/07 16:42:49 agc Exp $ */ 2 3 /* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)getgrouplist.c 8.2 (Berkeley) 12/8/94"; 36 #else 37 __RCSID("$NetBSD: getgrouplist.c,v 1.17 2003/08/07 16:42:49 agc Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 /* 42 * get credential 43 */ 44 #include "namespace.h" 45 #include <sys/param.h> 46 47 #include <assert.h> 48 #include <grp.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #ifdef __weak_alias 53 __weak_alias(getgrouplist,_getgrouplist) 54 #endif 55 56 /* 57 * _getgrent_user() is a libc-private function defined in getgrent.c which 58 * use because certain name service types such as Hesiod lookup grouplists 59 * by username rather than just iterating over the list of groups. 60 */ 61 struct group *_getgrent_user(const char *); 62 63 int 64 getgrouplist(uname, agroup, groups, grpcnt) 65 const char *uname; 66 gid_t agroup; 67 gid_t *groups; 68 int *grpcnt; 69 { 70 struct group *grp; 71 int i, ngroups; 72 int ret, maxgroups; 73 74 _DIAGASSERT(uname != NULL); 75 _DIAGASSERT(groups != NULL); 76 _DIAGASSERT(grpcnt != NULL); 77 78 ret = 0; 79 ngroups = 0; 80 maxgroups = *grpcnt; 81 82 /* 83 * install primary group 84 */ 85 if (ngroups < maxgroups) 86 groups[ngroups] = agroup; 87 else 88 ret = -1; 89 ngroups++; 90 91 /* 92 * Scan the group file to find additional groups. 93 */ 94 setgrent(); 95 nextgroup: 96 while ((grp = _getgrent_user(uname)) != NULL) { 97 if (grp->gr_gid == agroup) 98 continue; 99 for (i = 0; i < MIN(ngroups, maxgroups); i++) { 100 if (grp->gr_gid == groups[i]) 101 goto nextgroup; 102 } 103 if (ngroups < maxgroups) 104 groups[ngroups] = grp->gr_gid; 105 else 106 ret = -1; 107 ngroups++; 108 } 109 endgrent(); 110 *grpcnt = ngroups; 111 return (ret); 112 } 113