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/* Copyright (C) 1997-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Thorsten Kukuk <kukuk@vt.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 <time.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <rpc/pmap_prot.h>
#include <rpc/pmap_clnt.h>
#include <rpcsvc/nis.h>
#include "nis_intern.h"
/* Private data kept per client handle, from sunrpc/clnt_udp.c */
struct cu_data
{
int cu_sock;
bool_t cu_closeit;
struct sockaddr_in cu_raddr;
int cu_rlen;
struct timeval cu_wait;
struct timeval cu_total;
struct rpc_err cu_error;
XDR cu_outxdrs;
u_int cu_xdrpos;
u_int cu_sendsz;
char *cu_outbuf;
u_int cu_recvsz;
char cu_inbuf[1];
};
/*
* Find the mapped port for program,version.
* Calls the pmap service remotely to do the lookup.
* Returns 0 if no map exists.
*/
u_short
__pmap_getnisport (struct sockaddr_in *address, u_long program,
u_long version, u_int protocol)
{
return __libc_rpc_getport (address, program, version, protocol, 1, 1);
}
/* This is now the public function, which should find the fastest server */
struct findserv_req
{
struct sockaddr_in sin;
uint32_t xid;
u_int server_nr;
u_int server_ep;
};
static long int
__nis_findfastest_with_timeout (dir_binding *bind,
const struct timeval *timeout)
{
static const struct timeval TIMEOUT00 = { 0, 0 };
struct findserv_req *pings;
struct sockaddr_in sin, saved_sin;
int found = -1;
uint32_t xid_seed;
int sock, dontblock = 1;
CLIENT *clnt;
u_long i, j, pings_count, pings_max, fastest = -1;
struct cu_data *cu;
pings_max = bind->server_len * 2; /* Reserve a little bit more memory
for multihomed hosts */
pings_count = 0;
pings = malloc (sizeof (struct findserv_req) * pings_max);
xid_seed = (uint32_t) (time (NULL) ^ getpid ());
if (__glibc_unlikely (pings == NULL))
return -1;
memset (&sin, '\0', sizeof (sin));
sin.sin_family = AF_INET;
for (i = 0; i < bind->server_len; i++)
for (j = 0; j < bind->server_val[i].ep.ep_len; ++j)
if (strcmp (bind->server_val[i].ep.ep_val[j].family, "inet") == 0)
if ((bind->server_val[i].ep.ep_val[j].proto == NULL)
|| (bind->server_val[i].ep.ep_val[j].proto[0] == '-')
|| (bind->server_val[i].ep.ep_val[j].proto[0] == '\0'))
{
sin.sin_addr.s_addr =
inetstr2int (bind->server_val[i].ep.ep_val[j].uaddr);
if (sin.sin_addr.s_addr == 0)
continue;
sin.sin_port = htons (__pmap_getnisport (&sin, NIS_PROG,
NIS_VERSION,
IPPROTO_UDP));
if (sin.sin_port == 0)
continue;
if (pings_count >= pings_max)
{
struct findserv_req *new_pings;
pings_max += 10;
new_pings = realloc (pings, sizeof (struct findserv_req) *
pings_max);
if (__glibc_unlikely (new_pings == NULL))
{
free (pings);
return -1;
}
pings = new_pings;
}
memcpy ((char *) &pings[pings_count].sin, (char *) &sin,
sizeof (sin));
memcpy ((char *)&saved_sin, (char *)&sin, sizeof (sin));
pings[pings_count].xid = xid_seed + pings_count;
pings[pings_count].server_nr = i;
pings[pings_count].server_ep = j;
++pings_count;
}
/* Make sure at least one server was assigned */
if (pings_count == 0)
{
free (pings);
return -1;
}
/* Create RPC handle */
sock = socket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
clnt = clntudp_create (&saved_sin, NIS_PROG, NIS_VERSION, *timeout, &sock);
if (clnt == NULL)
{
close (sock);
free (pings);
return -1;
}
auth_destroy (clnt->cl_auth);
clnt->cl_auth = authunix_create_default ();
cu = (struct cu_data *) clnt->cl_private;
ioctl (sock, FIONBIO, &dontblock);
/* Send to all servers the NULLPROC */
for (i = 0; i < pings_count; ++i)
{
/* clntudp_call() will increment, subtract one */
*((uint32_t *) (cu->cu_outbuf)) = pings[i].xid - 1;
memcpy ((char *) &cu->cu_raddr, (char *) &pings[i].sin,
sizeof (struct sockaddr_in));
/* Transmit to NULLPROC, return immediately. */
clnt_call (clnt, NULLPROC,
(xdrproc_t) xdr_void, (caddr_t) 0,
(xdrproc_t) xdr_void, (caddr_t) 0, TIMEOUT00);
}
while (found == -1) {
/* Receive reply from NULLPROC asynchronously. Note null inproc. */
int rc = clnt_call (clnt, NULLPROC,
(xdrproc_t) NULL, (caddr_t) 0,
(xdrproc_t) xdr_void, (caddr_t) 0,
*timeout);
if (RPC_SUCCESS == rc) {
uint32_t val;
memcpy (&val, cu->cu_inbuf, sizeof (uint32_t));
fastest = val - xid_seed;
if (fastest < pings_count) {
bind->server_used = pings[fastest].server_nr;
bind->current_ep = pings[fastest].server_ep;
found = 1;
}
} else {
/* clnt_perror(clnt, "__nis_findfastest"); */
break;
}
}
auth_destroy (clnt->cl_auth);
clnt_destroy (clnt);
close (sock);
free (pings);
return found;
}
long int
__nis_findfastest (dir_binding *bind)
{
struct timeval timeout = { __NIS_PING_TIMEOUT_START, 0 };
long int found = -1;
long int retry = __NIS_PING_RETRY + 1;
while (retry--)
{
found = __nis_findfastest_with_timeout (bind, &timeout);
if (found != -1)
break;
timeout.tv_sec += __NIS_PING_TIMEOUT_INCREMENT;
}
return found;
}
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