Client code

#define WIN$32\_$LEAN$\_$AND$\_$MEAN

#include

#include

#include

#include

#include

$//$ Need to link with Ws$2\_32.$lib, Mswsock.lib, and Advapi$32.$lib

#pragma comment $($lib$,"$Ws$2\_32.$lib"$)$

#pragma comment $($lib$,$ "Mswsock.lib"$)$

#pragma comment $($lib$,$ "AdvApi$32.$lib"$)$

#define DEFAULT$\_$BUFLEN $512$

#define DEFAULT$\_$PORT $"27015"$

int $\_\_$cdecl main$($int argc, char $**$argv$)$

$\{$

WSADATA wsaData;

SOCKET ConnectSocket $=$ INVALID$\_$SOCKET;

struct addrinfo $*$result $=$ NULL,

$*$ptr $=$ NULL,

hints;

const char $*$sendbuf $=$ "this is a test";

char recvbuf$[$DEFAULT$\_$BUFLEN$]$;

int iResult;

int recvbuflen $=$ DEFAULT$\_$BUFLEN;

$//$ Validate the parameters

if $($argc $!=2)\{$

printf$("$usage: $\%$s server$-$name

$",$ argv$[0])$;

return $1$;

$\}$

$//$ Initialize Winsock

iResult $=$ WSAStartup$($MAKEWORD$(2,2),$ &wsaData$)$;

if $($iResult $!=0)\{$

printf$("$WSAStartup failed with error: $\%$d

$",$ iResult$)$;

return $1$;

$\}$

ZeroMemory$($ &hints, sizeof$($hints$))$;

hints.ai$\_$family $=$ AF$\_$UNSPEC;

hints.ai$\_$socktype $=$ SOCK$\_$STREAM;

hints.ai$\_$protocol $=$ IPPROTO$\_$TCP;

$//$ Resolve the server address and port

iResult $=$ getaddrinfo$($argv$[1],$ DEFAULT$\_$PORT, &hints, &result$)$;

if $($ iResult $!=0)\{$

printf$("$getaddrinfo failed with error: $\%$d

$",$ iResult$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Attempt to connect to an address until one succeeds

for$($ptr$=$result; ptr $!=$ NULL ;ptr$=$ptr$->$ai$\_$next$)\{$

$//$ Create a SOCKET for connecting to server

ConnectSocket $=$ socket$($ptr$->$ai$\_$family, ptr$->$ai$\_$socktype,

ptr$->$ai$\_$protocol$)$;

if $($ConnectSocket $==$ INVALID$\_$SOCKET$)\{$

printf$("$socket failed with error: $\%$ld

$",$ WSAGetLastError$())$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Connect to server.

iResult $=$ connect$($ ConnectSocket, ptr$->$ai$\_$addr, $($int$)$ptr$->$ai$\_$addrlen$)$;

if $($iResult $==$ SOCKET$\_$ERROR$)\{$

closesocket$($ConnectSocket$)$;

ConnectSocket $=$ INVALID$\_$SOCKET;

continue;

$\}$

break;

$\}$

freeaddrinfo$($result$)$;

if $($ConnectSocket $==$ INVALID$\_$SOCKET$)\{$

printf$("$Unable to connect to server!

$")$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Send an initial buffer

iResult $=$ send$($ ConnectSocket, sendbuf$,($int$)$strlen$($sendbuf$),0)$;

if $($iResult $==$ SOCKET$\_$ERROR$)\{$

printf$("$send failed with error: $\%$d

$",$ WSAGetLastError$())$;

closesocket$($ConnectSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

printf$("$Bytes Sent: $\%$ld

$",$ iResult$)$;

$//$ shutdown the connection since no more data will be sent

iResult $=$ shutdown$($ConnectSocket$,$ SD$\_$SEND$)$;

if $($iResult $==$ SOCKET$\_$ERROR$)\{$

printf$("$shutdown failed with error: $\%$d

$",$ WSAGetLastError$())$;

closesocket$($ConnectSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Receive until the peer closes the connection

do $\{$

iResult $=$ recv$($ConnectSocket$,$ recvbuf, recvbuflen, $0)$;

if $($ iResult $>0)$

printf$("$Bytes received: $\%$d

$",$ iResult$)$;

else if $($ iResult $==0)$

printf$("$Connection closed

$")$;

else

printf$("$recv failed with error: $\%$d

$",$ WSAGetLastError$())$;

$\}$ while$($ iResult $>0)$;

$//$ cleanup

closesocket$($ConnectSocket$)$;

WSACleanup$()$;

return $0$;

$\}$

Server code

#undef UNICODE

#define WIN$32\_$LEAN$\_$AND$\_$MEAN

#include

#include

#include

#include

#include

$//$ Need to link with Ws$2\_32.$lib

#pragma comment $($lib$,"$Ws$2\_32.$lib"$)$

$//$ #pragma comment $($lib$,$ "Mswsock.lib"$)$

#define DEFAULT$\_$BUFLEN $512$

#define DEFAULT$\_$PORT $"27015"$

int $\_\_$cdecl main$($void$)$

$\{$

WSADATA wsaData;

int iResult;

SOCKET ListenSocket $=$ INVALID$\_$SOCKET;

SOCKET ClientSocket $=$ INVALID$\_$SOCKET;

struct addrinfo $*$result $=$ NULL;

struct addrinfo hints;

int iSendResult;

char recvbuf$[$DEFAULT$\_$BUFLEN$]$;

int recvbuflen $=$ DEFAULT$\_$BUFLEN;

$//$ Initialize Winsock

iResult $=$ WSAStartup$($MAKEWORD$(2,2),$ &wsaData$)$;

if $($iResult $!=0)\{$

printf$("$WSAStartup failed with error: $\%$d

$",$ iResult$)$;

return $1$;

$\}$

ZeroMemory$($&hints, sizeof$($hints$))$;

hints.ai$\_$family $=$ AF$\_$INET;

hints.ai$\_$socktype $=$ SOCK$\_$STREAM;

hints.ai$\_$protocol $=$ IPPROTO$\_$TCP;

hints.ai$\_$flags $=$ AI$\_$PASSIVE;

$//$ Resolve the server address and port

iResult $=$ getaddrinfo$($NULL$,$ DEFAULT$\_$PORT, &hints, &result$)$;

if $($ iResult $!=0)\{$

printf$("$getaddrinfo failed with error: $\%$d

$",$ iResult$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Create a SOCKET for the server to listen for client connections.

ListenSocket $=$ socket$($result$->$ai$\_$family, result$->$ai$\_$socktype, result$->$ai$\_$protocol$)$;

if $($ListenSocket $==$ INVALID$\_$SOCKET$)\{$

printf$("$socket failed with error: $\%$ld

$",$ WSAGetLastError$())$;

freeaddrinfo$($result$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Setup the TCP listening socket

iResult $=$ bind$($ ListenSocket, result$->$ai$\_$addr, $($int$)$result$->$ai$\_$addrlen$)$;

if $($iResult $==$ SOCKET$\_$ERROR$)\{$

printf$("$bind failed with error: $\%$d

$",$ WSAGetLastError$())$;

freeaddrinfo$($result$)$;

closesocket$($ListenSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

freeaddrinfo$($result$)$;

iResult $=$ listen$($ListenSocket$,$ SOMAXCONN$)$;

if $($iResult $==$ SOCKET$\_$ERROR$)\{$

printf$("$listen failed with error: $\%$d

$",$ WSAGetLastError$())$;

closesocket$($ListenSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ Accept a client socket

ClientSocket $=$ accept$($ListenSocket$,$ NULL, NULL$)$;

if $($ClientSocket $==$ INVALID$\_$SOCKET$)\{$

printf$("$accept failed with error: $\%$d

$",$ WSAGetLastError$())$;

closesocket$($ListenSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

$//$ No longer need server socket

closesocket$($ListenSocket$)$;

$//$ Receive until the peer shuts down the connection

do $\{$

iResult $=$ recv$($ClientSocket$,$ recvbuf, recvbuflen, $0)$;

if $($iResult $>0)\{$

printf$("$Bytes received: $\%$d

$",$ iResult$)$;

$//$ Echo the buffer back to the sender

iSendResult $=$ send$($ ClientSocket, recvbuf, iResult, $0)$;

if $($iSendResult $==$ SOCKET$\_$ERROR$)\{$

printf$("$send failed with error: $\%$d

$",$ WSAGetLastError$())$;

closesocket$($ClientSocket$)$;

WSACleanup$()$;

return $1$;

$\}$

printf$("$Bytes sent: $\%$d

$",$ iSendResult$)$;

$\}$

else if $($iResult $==0)$

printf$("$Connection closing...