/* * initgroups.c - This file is part of the libc-8086/grp package for ELKS, * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include <unistd.h> #include <string.h> #include <fcntl.h> #include <paths.h> #include <stdlib.h> #include <errno.h> #include "config.h" #ifdef __UCLIBC_HAS_THREADS__ #include <pthread.h> extern pthread_mutex_t __getgrent_lock; # define LOCK pthread_mutex_lock(&__getgrent_lock) # define UNLOCK pthread_mutex_unlock(&__getgrent_lock); #else # define LOCK # define UNLOCK #endif static char *line_buff = NULL; static char **members = NULL; int initgroups(__const char *user, gid_t gid) { register struct group *group; gid_t *group_list = NULL; register char **tmp_mem; int num_groups; int grp_fd; if ((grp_fd = open(_PATH_GROUP, O_RDONLY)) < 0) return errno; num_groups = 0; group_list = (gid_t *) realloc(group_list, 1); group_list[num_groups] = gid; LOCK; while ((group = __getgrent(grp_fd, line_buff, members)) != NULL) { if (group->gr_gid != gid) { tmp_mem = group->gr_mem; while (*tmp_mem != NULL) { if (!strcmp(*tmp_mem, user)) { num_groups++; group_list = (gid_t *) realloc(group_list, num_groups * sizeof(gid_t *)); group_list[num_groups-1] = group->gr_gid; } tmp_mem++; } } } close(grp_fd); UNLOCK; return setgroups(num_groups, group_list); }