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/* Copyright (C) 1989, 91, 93, 1996-1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C 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.
The GNU C 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 the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <alloca.h>
#include <errno.h>
#include <grp.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <nsswitch.h>
/* Type of the lookup function. */
typedef enum nss_status (*initgroups_function) (const char *, gid_t,
long int *, long int *,
gid_t *, long int, int *);
/* Prototype for the setgrent functions we use here. */
typedef enum nss_status (*set_function) (void);
/* Prototype for the endgrent functions we use here. */
typedef enum nss_status (*end_function) (void);
/* Prototype for the setgrent functions we use here. */
typedef enum nss_status (*get_function) (struct group *, char *,
size_t, int *);
/* The lookup function for the first entry of this service. */
extern int __nss_group_lookup (service_user **nip, const char *name,
void **fctp);
extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
extern service_user *__nss_group_database;
static enum nss_status
compat_call (service_user *nip, const char *user, gid_t group, long int *start,
long int *size, gid_t **groupsp, int *errnop)
{
struct group grpbuf;
size_t buflen = __sysconf (_SC_GETGR_R_SIZE_MAX);
char *tmpbuf;
enum nss_status status;
set_function setgrent_fct;
get_function getgrent_fct;
end_function endgrent_fct;
gid_t *groups = *groupsp;
getgrent_fct = __nss_lookup_function (nip, "getgrent_r");
if (getgrent_fct == NULL)
return NSS_STATUS_UNAVAIL;
setgrent_fct = __nss_lookup_function (nip, "setgrent");
if (setgrent_fct)
{
status = DL_CALL_FCT (setgrent_fct, ());
if (status != NSS_STATUS_SUCCESS)
return status;
}
endgrent_fct = __nss_lookup_function (nip, "endgrent");
tmpbuf = __alloca (buflen);
do
{
while ((status = DL_CALL_FCT (getgrent_fct,
(&grpbuf, tmpbuf, buflen, errnop)),
status == NSS_STATUS_TRYAGAIN)
&& *errnop == ERANGE)
{
buflen *= 2;
tmpbuf = __alloca (buflen);
}
if (status != NSS_STATUS_SUCCESS)
goto done;
if (grpbuf.gr_gid != group)
{
char **m;
for (m = grpbuf.gr_mem; *m != NULL; ++m)
if (strcmp (*m, user) == 0)
{
/* Matches user. Insert this group. */
if (__builtin_expect (*start == *size, 0))
{
/* Need a bigger buffer. */
gid_t *newgroups;
newgroups = realloc (groups, 2 * *size * sizeof (*groups));
if (newgroups == NULL)
goto done;
*groupsp = groups = newgroups;
*size *= 2;
}
groups[*start] = grpbuf.gr_gid;
*start += 1;
break;
}
}
}
while (status == NSS_STATUS_SUCCESS);
done:
if (endgrent_fct)
DL_CALL_FCT (endgrent_fct, ());
return NSS_STATUS_SUCCESS;
}
/* Initialize the group set for the current user
by reading the group database and using all groups
of which USER is a member. Also include GROUP. */
int
initgroups (user, group)
const char *user;
gid_t group;
{
#if defined NGROUPS_MAX && NGROUPS_MAX == 0
/* No extra groups allowed. */
return 0;
#else
service_user *nip = NULL;
initgroups_function fct;
enum nss_status status = NSS_STATUS_UNAVAIL;
int no_more;
/* Start is one, because we have the first group as parameter. */
long int start = 1;
long int size;
gid_t *groups;
int result;
#ifdef NGROUPS_MAX
size = NGROUPS_MAX;
#else
long int limit = __sysconf (_SC_NGROUPS_MAX);
if (limit > 0)
size = limit;
else
/* No fixed limit on groups. Pick a starting buffer size. */
size = 16;
#endif
groups = (gid_t *) malloc (size * sizeof (gid_t));
if (__builtin_expect (groups == NULL, 0))
/* No more memory. */
return -1;
groups[0] = group;
if (__nss_group_database != NULL)
{
no_more = 0;
nip = __nss_group_database;
}
else
no_more = __nss_database_lookup ("group", NULL,
"compat [NOTFOUND=return] files", &nip);
while (! no_more)
{
fct = __nss_lookup_function (nip, "initgroups_dyn");
if (fct == NULL)
{
status = compat_call (nip, user, group, &start, &size, &groups,
&errno);
if (nss_next_action (nip, NSS_STATUS_UNAVAIL) != NSS_ACTION_CONTINUE)
break;
}
else
status = DL_CALL_FCT (fct, (user, group, &start, &size, &groups,
&errno));
/* This is really only for debugging. */
if (NSS_STATUS_TRYAGAIN > status || status > NSS_STATUS_RETURN)
__libc_fatal ("illegal status in " __FUNCTION__);
if (status != NSS_STATUS_SUCCESS
&& nss_next_action (nip, status) == NSS_ACTION_RETURN)
break;
if (nip->next == NULL)
no_more = -1;
else
nip = nip->next;
}
/* Try to set the maximum number of groups the kernel can handle. */
do
result = setgroups (start, groups);
while (result == -1 && errno == EINVAL && --start > 0);
return result;
#endif
}
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