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/*
* 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 "busybox.h"
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include "grp_.h"
/*
* Define GR_SCALE_DYNAMIC if you want grp to dynamically scale its read buffer
* so that lines of any length can be used. On very very small systems,
* you may want to leave this undefined becasue it will make the grp functions
* somewhat larger (because of the inclusion of malloc and the code necessary).
* On larger systems, you will want to define this, because grp will _not_
* deal with long lines gracefully (they will be skipped).
*/
#undef GR_SCALE_DYNAMIC
#ifndef GR_SCALE_DYNAMIC
/*
* If scaling is not dynamic, the buffers will be statically allocated, and
* maximums must be chosen. GR_MAX_LINE_LEN is the maximum number of
* characters per line in the group file. GR_MAX_MEMBERS is the maximum
* number of members of any given group.
*/
#define GR_MAX_LINE_LEN 128
/* GR_MAX_MEMBERS = (GR_MAX_LINE_LEN-(24+3+6))/9 */
#define GR_MAX_MEMBERS 11
#endif /* !GR_SCALE_DYNAMIC */
/*
* Define GR_DYNAMIC_GROUP_LIST to make initgroups() dynamically allocate
* space for it's GID array before calling setgroups(). This is probably
* unnecessary scalage, so it's undefined by default.
*/
#undef GR_DYNAMIC_GROUP_LIST
#ifndef GR_DYNAMIC_GROUP_LIST
/*
* GR_MAX_GROUPS is the size of the static array initgroups() uses for
* its static GID array if GR_DYNAMIC_GROUP_LIST isn't defined.
*/
#define GR_MAX_GROUPS 64
#endif /* !GR_DYNAMIC_GROUP_LIST */
int initgroups(__const char *user, gid_t gid)
{
register struct group *group;
#ifndef GR_DYNAMIC_GROUP_LIST
gid_t group_list[GR_MAX_GROUPS];
#else
gid_t *group_list = NULL;
#endif
register char **tmp_mem;
int num_groups;
int grp_fd;
if ((grp_fd = open("/etc/group", O_RDONLY)) < 0)
return -1;
num_groups = 0;
#ifdef GR_DYNAMIC_GROUP_LIST
group_list = (gid_t *) realloc(group_list, 1);
#endif
group_list[num_groups] = gid;
#ifndef GR_DYNAMIC_GROUP_LIST
while (num_groups < GR_MAX_GROUPS &&
(group = __getgrent(grp_fd)) != NULL)
#else
while ((group = __getgrent(grp_fd)) != NULL)
#endif
{
if (group->gr_gid != gid);
{
tmp_mem = group->gr_mem;
while (*tmp_mem != NULL) {
if (!strcmp(*tmp_mem, user)) {
num_groups++;
#ifdef GR_DYNAMIC_GROUP_LIST
group_list = (gid_t *) realloc(group_list, num_groups *
sizeof(gid_t *));
#endif
group_list[num_groups] = group->gr_gid;
}
tmp_mem++;
}
}
}
close(grp_fd);
return setgroups(num_groups, group_list);
}
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