kb4038779 - problem with getnameinfo()

Don't know whether this is a place to drop my question. Probably not. But maybe someone coudl guide me to the right place.


The following program stopped working after this patch (kb4038779) had been installed in Windows 7 Pro x64 SP1:

// gethostname.c :
//
// Testprogramm to show the failure of getnameinfo-function unter Windows (7,10, Windows Server 20xx with
// KB4038779 installed)
// CPK

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdio.h>
#include <sys/types.h>

typedef unsigned int SOCKET;

#include <Winsock2.h>
#include <ws2tcpip.h>

void usage(void);
int exit(int);
#define MAXHOSTNAMELEN 512

static char hostinfo[NI_MAXHOST];
static char hostname[MAXHOSTNAMELEN];

int main(int argc, char *argv[])
{
int result,err;
int wsreturn;
static char tmpstring[1024];
WORD wVersionRequested;
WSADATA wsaData;
SOCKADDR_IN sa;
sa.sin_family=AF_INET;
wVersionRequested = MAKEWORD( 2, 2 );

err = WSAStartup( wVersionRequested , &wsaData );
if ( err != 0 ) {
/* Tell the user that we couldn't find a usable */
/* winsock.dll. */
printf("server: couldn't find a Winsock 2.2!\n"),exit(3);
}
if(argc !=2)
usage();

inet_pton(AF_INET,argv[1], &(sa.sin_addr));

result=getnameinfo((struct sockaddr *)&sa,
sizeof (sa),hostinfo,NI_MAXHOST,NULL,0,0);
wsreturn=WSAGetLastError();
if(wsreturn!=0)
printf("WSockError=%d\n",wsreturn);
printf("CLIENT: ip=[%s] hostinfo=[%s] result=%d wsreturn=%d\n", argv[1],hostinfo,result,wsreturn);

return 0;

}
void usage() {
printf("gethostname <IP>\nz.B. gethostname 10.172.10.35\n"),exit(1);
}

Using it, gives the following result:

C:\>gethostname 172.27.1.252 ... a few (10) seconds of waiting here

CLIENT: ip=[172.27.1.252] hostinfo=[172.27.1.252] result=0 wsreturn=0

Without the patch

C:\>gethostname 172.27.1.252 ... no waiting here, immediate return

CLIENT: ip=[172.27.1.252] hostinfo=[some.host.domain] result=0 wsreturn=0

After a while the behaviour changed again to that of the situation without the patch.


--

Christoph Kukulies