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dd3022d75e
getnetgrent is supposed to return NULL for values that are wildcards
in the (host, user, domain) triplet. This works correctly with nscd
disabled, but with it enabled, it returns a blank ("") instead of a
NULL. This is easily seen with the output of `getent netgroup foonet`
for a netgroup foonet defined as follows in /etc/netgroup:
foonet (,foo,)
The output with nscd disabled is:
foonet ( ,foo,)
while with nscd enabled, it is:
foonet (,foo,)
The extra space with nscd disabled is due to the fact that `getent
netgroup` adds it if the return value from getnetgrent is NULL for
either host or user.
534 lines
14 KiB
C
534 lines
14 KiB
C
/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <atomic.h>
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#include <bits/libc-lock.h>
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#include <errno.h>
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#include <netdb.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#include "netgroup.h"
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#include "nsswitch.h"
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#include <sysdep.h>
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#include <nscd/nscd_proto.h>
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/* Protect above variable against multiple uses at the same time. */
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__libc_lock_define_initialized (static, lock)
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/* The whole information for the set/get/endnetgrent functions are
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kept in this structure. */
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static struct __netgrent dataset;
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/* The lookup function for the first entry of this service. */
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extern int __nss_netgroup_lookup (service_user **nipp, const char *name,
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void **fctp) internal_function;
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/* Set up NIP to run through the services. Return nonzero if there are no
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services (left). */
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static int
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setup (void **fctp, service_user **nipp)
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{
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/* Remember the first service_entry, it's always the same. */
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static bool startp_initialized;
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static service_user *startp;
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int no_more;
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if (!startp_initialized)
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{
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/* Executing this more than once at the same time must yield the
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same result every time. So we need no locking. */
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no_more = __nss_netgroup_lookup (nipp, "setnetgrent", fctp);
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startp = no_more ? (service_user *) -1 : *nipp;
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#ifdef PTR_MANGLE
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PTR_MANGLE (startp);
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#endif
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atomic_write_barrier ();
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startp_initialized = true;
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}
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else
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{
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service_user *nip = startp;
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#ifdef PTR_DEMANGLE
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PTR_DEMANGLE (nip);
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#endif
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if (nip == (service_user *) -1)
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/* No services at all. */
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return 1;
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/* Reset to the beginning of the service list. */
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*nipp = nip;
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/* Look up the first function. */
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no_more = __nss_lookup (nipp, "setnetgrent", NULL, fctp);
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}
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return no_more;
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}
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/* Free used memory. */
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static void
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free_memory (struct __netgrent *data)
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{
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while (data->known_groups != NULL)
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{
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struct name_list *tmp = data->known_groups;
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data->known_groups = data->known_groups->next;
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free (tmp);
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}
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while (data->needed_groups != NULL)
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{
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struct name_list *tmp = data->needed_groups;
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data->needed_groups = data->needed_groups->next;
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free (tmp);
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}
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}
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static void
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endnetgrent_hook (struct __netgrent *datap)
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{
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enum nss_status (*endfct) (struct __netgrent *);
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if (datap->nip == NULL || datap->nip == (service_user *) -1l)
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return;
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endfct = __nss_lookup_function (datap->nip, "endnetgrent");
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if (endfct != NULL)
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(void) (*endfct) (datap);
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datap->nip = NULL;
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}
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static int
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internal_function
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__internal_setnetgrent_reuse (const char *group, struct __netgrent *datap,
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int *errnop)
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{
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union
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{
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enum nss_status (*f) (const char *, struct __netgrent *);
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void *ptr;
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} fct;
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enum nss_status status = NSS_STATUS_UNAVAIL;
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struct name_list *new_elem;
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/* Free data from previous service. */
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endnetgrent_hook (datap);
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/* Cycle through all the services and run their setnetgrent functions. */
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int no_more = setup (&fct.ptr, &datap->nip);
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while (! no_more)
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{
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assert (datap->data == NULL);
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/* Ignore status, we force check in `__nss_next2'. */
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status = DL_CALL_FCT (*fct.f, (group, datap));
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service_user *old_nip = datap->nip;
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no_more = __nss_next2 (&datap->nip, "setnetgrent", NULL, &fct.ptr,
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status, 0);
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if (status == NSS_STATUS_SUCCESS && ! no_more)
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{
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enum nss_status (*endfct) (struct __netgrent *);
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endfct = __nss_lookup_function (old_nip, "endnetgrent");
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if (endfct != NULL)
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(void) DL_CALL_FCT (*endfct, (datap));
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}
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}
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/* Add the current group to the list of known groups. */
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size_t group_len = strlen (group) + 1;
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new_elem = (struct name_list *) malloc (sizeof (struct name_list)
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+ group_len);
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if (new_elem == NULL)
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{
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*errnop = errno;
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status = NSS_STATUS_TRYAGAIN;
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}
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else
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{
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new_elem->next = datap->known_groups;
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memcpy (new_elem->name, group, group_len);
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datap->known_groups = new_elem;
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}
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return status == NSS_STATUS_SUCCESS;
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}
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int
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internal_function
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__internal_setnetgrent (const char *group, struct __netgrent *datap)
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{
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/* Free list of all netgroup names from last run. */
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free_memory (datap);
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return __internal_setnetgrent_reuse (group, datap, &errno);
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}
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libc_hidden_def (__internal_setnetgrent)
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static int
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nscd_setnetgrent (const char *group)
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{
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#ifdef USE_NSCD
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if (__nss_not_use_nscd_netgroup > 0
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&& ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
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__nss_not_use_nscd_netgroup = 0;
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if (!__nss_not_use_nscd_netgroup
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&& !__nss_database_custom[NSS_DBSIDX_netgroup])
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return __nscd_setnetgrent (group, &dataset);
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#endif
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return -1;
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}
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int
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setnetgrent (const char *group)
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{
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int result;
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__libc_lock_lock (lock);
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result = nscd_setnetgrent (group);
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if (result < 0)
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result = __internal_setnetgrent (group, &dataset);
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__libc_lock_unlock (lock);
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return result;
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}
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void
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internal_function
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__internal_endnetgrent (struct __netgrent *datap)
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{
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endnetgrent_hook (datap);
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/* Now free list of all netgroup names from last run. */
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free_memory (datap);
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}
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libc_hidden_def (__internal_endnetgrent)
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void
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endnetgrent (void)
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{
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__libc_lock_lock (lock);
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__internal_endnetgrent (&dataset);
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__libc_lock_unlock (lock);
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}
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#ifdef USE_NSCD
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static const char *
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get_nonempty_val (const char *in)
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{
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if (*in == '\0')
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return NULL;
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return in;
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}
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static enum nss_status
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nscd_getnetgrent (struct __netgrent *datap, char *buffer, size_t buflen,
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int *errnop)
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{
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if (datap->cursor >= datap->data + datap->data_size)
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return NSS_STATUS_UNAVAIL;
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datap->type = triple_val;
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datap->val.triple.host = get_nonempty_val (datap->cursor);
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datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;
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datap->val.triple.user = get_nonempty_val (datap->cursor);
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datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;
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datap->val.triple.domain = get_nonempty_val (datap->cursor);
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datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;
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return NSS_STATUS_SUCCESS;
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}
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#endif
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int
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internal_function
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__internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
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struct __netgrent *datap,
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char *buffer, size_t buflen, int *errnop)
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{
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enum nss_status (*fct) (struct __netgrent *, char *, size_t, int *);
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/* Initialize status to return if no more functions are found. */
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enum nss_status status = NSS_STATUS_NOTFOUND;
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/* Run through available functions, starting with the same function last
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run. We will repeat each function as long as it succeeds, and then go
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on to the next service action. */
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int no_more = datap->nip == NULL;
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if (! no_more)
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{
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#ifdef USE_NSCD
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/* This bogus function pointer is a special marker left by
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__nscd_setnetgrent to tell us to use the data it left
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before considering any modules. */
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if (datap->nip == (service_user *) -1l)
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fct = nscd_getnetgrent;
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else
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#endif
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{
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fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
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no_more = fct == NULL;
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}
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}
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while (! no_more)
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{
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status = DL_CALL_FCT (*fct, (datap, buffer, buflen, &errno));
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if (status == NSS_STATUS_RETURN)
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{
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/* This was the last one for this group. Look at next group
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if available. */
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int found = 0;
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while (datap->needed_groups != NULL && ! found)
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{
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struct name_list *tmp = datap->needed_groups;
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datap->needed_groups = datap->needed_groups->next;
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tmp->next = datap->known_groups;
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datap->known_groups = tmp;
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found = __internal_setnetgrent_reuse (datap->known_groups->name,
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datap, errnop);
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}
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if (found && datap->nip != NULL)
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{
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fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
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if (fct != NULL)
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continue;
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}
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}
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else if (status == NSS_STATUS_SUCCESS && datap->type == group_val)
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{
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/* The last entry was a name of another netgroup. */
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struct name_list *namep;
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/* Ignore if we've seen the name before. */
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for (namep = datap->known_groups; namep != NULL;
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namep = namep->next)
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if (strcmp (datap->val.group, namep->name) == 0)
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break;
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if (namep == NULL)
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for (namep = datap->needed_groups; namep != NULL;
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namep = namep->next)
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if (strcmp (datap->val.group, namep->name) == 0)
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break;
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if (namep != NULL)
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/* Really ignore. */
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continue;
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size_t group_len = strlen (datap->val.group) + 1;
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namep = (struct name_list *) malloc (sizeof (struct name_list)
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+ group_len);
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if (namep == NULL)
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/* We are out of memory. */
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status = NSS_STATUS_RETURN;
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else
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{
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namep->next = datap->needed_groups;
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memcpy (namep->name, datap->val.group, group_len);
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datap->needed_groups = namep;
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/* And get the next entry. */
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continue;
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}
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}
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break;
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}
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if (status == NSS_STATUS_SUCCESS)
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{
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*hostp = (char *) datap->val.triple.host;
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*userp = (char *) datap->val.triple.user;
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*domainp = (char *) datap->val.triple.domain;
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}
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return status == NSS_STATUS_SUCCESS ? 1 : 0;
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}
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libc_hidden_def (__internal_getnetgrent_r)
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/* The real entry point. */
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int
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__getnetgrent_r (char **hostp, char **userp, char **domainp,
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char *buffer, size_t buflen)
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{
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enum nss_status status;
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__libc_lock_lock (lock);
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status = __internal_getnetgrent_r (hostp, userp, domainp, &dataset,
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buffer, buflen, &errno);
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__libc_lock_unlock (lock);
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return status;
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}
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weak_alias (__getnetgrent_r, getnetgrent_r)
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/* Test whether given (host,user,domain) triple is in NETGROUP. */
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int
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innetgr (const char *netgroup, const char *host, const char *user,
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const char *domain)
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{
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#ifdef USE_NSCD
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if (__nss_not_use_nscd_netgroup > 0
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&& ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
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__nss_not_use_nscd_netgroup = 0;
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if (!__nss_not_use_nscd_netgroup
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&& !__nss_database_custom[NSS_DBSIDX_netgroup])
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{
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int result = __nscd_innetgr (netgroup, host, user, domain);
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if (result >= 0)
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return result;
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}
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#endif
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union
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{
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enum nss_status (*f) (const char *, struct __netgrent *);
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void *ptr;
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} setfct;
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void (*endfct) (struct __netgrent *);
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int (*getfct) (struct __netgrent *, char *, size_t, int *);
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struct __netgrent entry;
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int result = 0;
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const char *current_group = netgroup;
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memset (&entry, '\0', sizeof (entry));
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/* Walk through the services until we found an answer or we shall
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not work further. We can do some optimization here. Since all
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services must provide the `setnetgrent' function we can do all
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the work during one walk through the service list. */
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while (1)
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{
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int no_more = setup (&setfct.ptr, &entry.nip);
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while (! no_more)
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{
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assert (entry.data == NULL);
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/* Open netgroup. */
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enum nss_status status = DL_CALL_FCT (*setfct.f,
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(current_group, &entry));
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if (status == NSS_STATUS_SUCCESS
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&& (getfct = __nss_lookup_function (entry.nip, "getnetgrent_r"))
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!= NULL)
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{
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char buffer[1024];
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while (DL_CALL_FCT (*getfct,
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(&entry, buffer, sizeof buffer, &errno))
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== NSS_STATUS_SUCCESS)
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{
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if (entry.type == group_val)
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{
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/* Make sure we haven't seen the name before. */
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struct name_list *namep;
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for (namep = entry.known_groups; namep != NULL;
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namep = namep->next)
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if (strcmp (entry.val.group, namep->name) == 0)
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break;
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if (namep == NULL)
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for (namep = entry.needed_groups; namep != NULL;
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namep = namep->next)
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if (strcmp (entry.val.group, namep->name) == 0)
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break;
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if (namep == NULL
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&& strcmp (netgroup, entry.val.group) != 0)
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{
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size_t group_len = strlen (entry.val.group) + 1;
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namep =
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(struct name_list *) malloc (sizeof (*namep)
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+ group_len);
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if (namep == NULL)
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{
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/* Out of memory, simply return. */
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result = -1;
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break;
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}
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namep->next = entry.needed_groups;
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memcpy (namep->name, entry.val.group, group_len);
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entry.needed_groups = namep;
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}
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}
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else
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{
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if ((entry.val.triple.host == NULL || host == NULL
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|| __strcasecmp (entry.val.triple.host, host) == 0)
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&& (entry.val.triple.user == NULL || user == NULL
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|| strcmp (entry.val.triple.user, user) == 0)
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&& (entry.val.triple.domain == NULL || domain == NULL
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|| __strcasecmp (entry.val.triple.domain,
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domain) == 0))
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{
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result = 1;
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break;
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}
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}
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}
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/* If we found one service which does know the given
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netgroup we don't try further. */
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status = NSS_STATUS_RETURN;
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}
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/* Free all resources of the service. */
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endfct = __nss_lookup_function (entry.nip, "endnetgrent");
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if (endfct != NULL)
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DL_CALL_FCT (*endfct, (&entry));
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if (result != 0)
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break;
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/* Look for the next service. */
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no_more = __nss_next2 (&entry.nip, "setnetgrent", NULL,
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&setfct.ptr, status, 0);
|
||
}
|
||
|
||
if (result == 0 && entry.needed_groups != NULL)
|
||
{
|
||
struct name_list *tmp = entry.needed_groups;
|
||
entry.needed_groups = tmp->next;
|
||
tmp->next = entry.known_groups;
|
||
entry.known_groups = tmp;
|
||
current_group = tmp->name;
|
||
continue;
|
||
}
|
||
|
||
/* No way out. */
|
||
break;
|
||
}
|
||
|
||
/* Free the memory. */
|
||
free_memory (&entry);
|
||
|
||
return result == 1;
|
||
}
|
||
libc_hidden_def (innetgr)
|