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/* Copyright (C) 1997-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <string.h>
#include <rpcsvc/nis.h>
#include "nis_xdr.h"
#include "nis_intern.h"
#include <libnsl.h>
#include <shlib-compat.h>
nis_result *
nis_lookup (const_nis_name name, const unsigned int flags)
{
nis_result *res = calloc (1, sizeof (nis_result));
struct ns_request req;
nis_name *names;
nis_error status;
int link_first_try = 0;
int count_links = 0; /* We will follow only 16 links in the deep */
int done = 0;
int name_nr = 0;
nis_name namebuf[2] = {NULL, NULL};
if (res == NULL)
return NULL;
if ((flags & EXPAND_NAME) && (name[strlen (name) - 1] != '.'))
{
names = nis_getnames (name);
if (names == NULL)
{
NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE;
return res;
}
}
else
{
names = namebuf;
names[0] = (nis_name)name;
}
req.ns_name = names[0];
while (!done)
{
dir_binding bptr;
directory_obj *dir = NULL;
req.ns_object.ns_object_len = 0;
req.ns_object.ns_object_val = NULL;
status = __prepare_niscall (req.ns_name, &dir, &bptr, flags);
if (__glibc_unlikely (status != NIS_SUCCESS))
{
NIS_RES_STATUS (res) = status;
goto out;
}
do
{
static const struct timeval RPCTIMEOUT = {10, 0};
enum clnt_stat result;
again:
result = clnt_call (bptr.clnt, NIS_LOOKUP,
(xdrproc_t) _xdr_ns_request,
(caddr_t) &req, (xdrproc_t) _xdr_nis_result,
(caddr_t) res, RPCTIMEOUT);
if (result != RPC_SUCCESS)
status = NIS_RPCERROR;
else
{
status = NIS_SUCCESS;
if (NIS_RES_STATUS (res) == NIS_SUCCESS)
{
if (__type_of (NIS_RES_OBJECT (res)) == NIS_LINK_OBJ
&& (flags & FOLLOW_LINKS)) /* We are following links */
{
/* if we hit the link limit, bail */
if (count_links > NIS_MAXLINKS)
{
NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
break;
}
++count_links;
req.ns_name =
strdupa (NIS_RES_OBJECT (res)->LI_data.li_name);
/* The following is a non-obvious optimization. A
nis_freeresult call would call xdr_free as the
following code. But it also would unnecessarily
free the result structure. We avoid this here
along with the necessary tests. */
xdr_free ((xdrproc_t) _xdr_nis_result, (char *) res);
memset (res, '\0', sizeof (*res));
link_first_try = 1; /* Try at first the old binding */
goto again;
}
}
else
if (NIS_RES_STATUS (res) == NIS_SYSTEMERROR
|| NIS_RES_STATUS (res) == NIS_NOSUCHNAME
|| NIS_RES_STATUS (res) == NIS_NOT_ME)
{
if (link_first_try)
{
__nisbind_destroy (&bptr);
nis_free_directory (dir);
/* Otherwise __nisfind_server will not do anything. */
dir = NULL;
if (__nisfind_server (req.ns_name, 1, &dir, &bptr,
flags & ~MASTER_ONLY)
!= NIS_SUCCESS)
goto out;
}
else
if (__nisbind_next (&bptr) != NIS_SUCCESS)
{
/* No more servers to search. Try parent. */
const char *ndomain = __nis_domain_of (req.ns_name);
req.ns_name = strdupa (ndomain);
if (strcmp (req.ns_name, ".") == 0)
{
NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE;
goto out;
}
__nisbind_destroy (&bptr);
nis_free_directory (dir);
dir = NULL;
status = __prepare_niscall (req.ns_name, &dir,
&bptr, flags);
if (__glibc_unlikely (status != NIS_SUCCESS))
{
NIS_RES_STATUS (res) = status;
goto out;
}
goto again;
}
while (__nisbind_connect (&bptr) != NIS_SUCCESS)
{
if (__nisbind_next (&bptr) != NIS_SUCCESS)
{
nis_free_directory (dir);
goto out;
}
}
goto again;
}
break;
}
link_first_try = 0; /* Set it back */
}
while ((flags & HARD_LOOKUP) && status == NIS_RPCERROR);
__nisbind_destroy (&bptr);
nis_free_directory (dir);
if (status != NIS_SUCCESS)
{
NIS_RES_STATUS (res) = status;
goto out;
}
switch (NIS_RES_STATUS (res))
{
case NIS_PARTIAL:
case NIS_SUCCESS:
case NIS_S_SUCCESS:
case NIS_LINKNAMEERROR: /* We follow to max links */
case NIS_UNAVAIL: /* NIS+ is not installed, or all servers are down */
++done;
break;
default:
/* Try the next domainname if we don't follow a link */
if (count_links)
{
free (req.ns_name);
NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
++done;
break;
}
++name_nr;
if (names[name_nr] == NULL)
{
++done;
break;
}
req.ns_name = names[name_nr];
break;
}
}
out:
if (names != namebuf)
nis_freenames (names);
return res;
}
libnsl_hidden_nolink_def (nis_lookup, GLIBC_2_1)
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