The following two pieces of code compile, but I get a connect() failed error on the client side. (compiled with MinGW).
Client Code:
// thanks to cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoClientWS.c
#include <stdio.h>
#include <winsock.h>
#include <stdlib.h>
#define RCVBUFSIZE 32 // size of receive buffer
void DieWithError(char *errorMessage);
int main(int argc, char* argv[])
{
int sock;
struct sockaddr_in echoServAddr;
unsigned short echoServPort;
char *servIP;
char *echoString;
char echoBuffer[RCVBUFSIZE];
int echoStringLen;
int bytesRcvd, totalBytesRcvd;
WSAData wsaData;
if((argc < 3) || (argc > 4)){
fprintf(stderr, "Usage: %s <Sever IP> <Echo Word> [<Echo Port>]\n", argv[0]);
exit(1);
}
if (argc==4)
echoServPort = atoi(argv[3]); // use given port if any
else
echoServPort = 7; // echo is well-known port for echo service
if(WSAStartup(MAKEWORD(2, 0), &wsaData) != 0){ // load winsock 2.0 dll
fprintf(stderr, "WSAStartup() failed");
exit(1);
}
// create reliable, stream socket using tcp
if((sock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
DieWithError("socket() failed");
// construct the server address structure
memset(&echoServAddr, 0, sizeof(echoServAddr));
echoServAddr.sin_family = AF_INET;
echoServAddr.sin_addr.s_addr = inet_addr(servIP); // server IP address
echoServAddr.sin_port = htons(echoServPort);
// establish connection to the echo server
if(connect(sock, (struct sockaddr*)&echoServAddr, sizeof(echoServAddr)) < 0)
DieWithError("connect() failed");
echoStringLen = strlen(echoString); // determine input length
// send the string, includeing the null terminator to the server
if(send(sock, echoString, echoStringLen, 0)!= echoStringLen)
DieWithError("send() sent a different number of bytes than expected");
totalBytesRcvd = 0;
printf("Received: "); // setup to print the echoed string
while(totalBytesRcvd < echoStringLen){
// receive up to the buffer size (minus 1 to leave space for a null terminator) bytes from the sender
if(bytesRcvd = recv(sock, echoBuffer, RCVBUFSIZE-1, 0) <= 0)
DieWithError("recv() failed or connection closed prematurely");
totalBytesRcvd += bytesRcvd; // keep tally of total bytes
echoBuffer[bytesRcvd] = '\0';
printf("%s", echoBuffer); // print the echo buffer
}
printf("\n");
closesocket(sock);
WSACleanup();
exit(0);
}
void DieWithError(char *errorMessage)
{
fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError());
exit(1);
}
Server Code:
// thanks cs.baylor.edu/~donahoo/practical/CSockets/code/TCPEchoServerWS.c
#include <stdio.h>
#include <winsock.h>
#include <stdlib.h>
#define MAXPENDING 5 // maximum outstanding connection requests
#define RCVBUFSIZE 1000
void DieWithError(char *errorMessage);
void HandleTCPClient(int clntSocket); // tcp client handling function
int main(int argc, char **argv)
{
int serverSock;
int clientSock;
struct sockaddr_in echoServerAddr;
struct sockaddr_in echoClientAddr;
unsigned short echoServerPort;
int clientLen; // length of client address data structure
WSAData wsaData;
if (argc!=2){
fprintf(stderr, "Usage: %s <Server Port>\n", argv[0]);
exit(1);
}
echoServerPort = atoi(argv[1]);
if(WSAStartup(MAKEWORD(2, 0), &wsaData)!=0){
fprintf(stderr, "WSAStartup() failed");
exit(1);
}
// create socket for incoming connections
if((serverSock=socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))<0)
DieWithError("socket() failed");
// construct local address structure
memset(&echoServerAddr, 0, sizeof(echoServerAddr));
echoServerAddr.sin_family = AF_INET;
echoServerAddr.sin_addr.s_addr = htonl(INADDR_ANY); // any incoming interface
echoServerAddr.sin_port = htons(echoServerPort); // local port
// bind to the local address
if(bind(serverSock,
(struct sockaddr*)&echoServerAddr,
sizeof(echoServerAddr)
)<0)
DieWithError("bind() failed");
// mark the socket so it will listen for incoming connections
if(listen(serverSock, MAXPENDING)<0)
DieWithError("listen() failed");
for (;;){ // run forever
// set the size of the in-out parameter
clientLen = sizeof(echoClientAddr);
// wait for a client to connect
if((clientSock = accept(serverSock, (struct sockaddr*)&echoClientAddr,
&clientLen)) < 0)
DieWithError("accept() failed");
// clientSock is connected to a client
printf("Handling client %s\n", inet_ntoa(echoClientAddr.sin_addr));
HandleTCPClient(clientSock);
}
// NOT REACHED
}
void DieWithError(char *errorMessage)
{
fprintf(stderr, "%s: %d\n", errorMessage, WSAGetLastError());
exit(1);
}
void HandleTCPClient(int clientSocket)
{
char echoBuffer[RCVBUFSIZE]; // buffer for echostring
int recvMsgSize; // size of received message
// receive message from client
if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0) <0))
DieWithError("recv() failed");
// send received string and receive again until end of transmission
while(recvMsgSize > 0){
// echo message back to client
if(send(clientSocket, echoBuffer, recvMsgSize, 0)!=recvMsgSize)
DieWithError("send() failed");
// see if there's more data to receive
if((recvMsgSize = recv(clientSocket, echoBuffer, RCVBUFSIZE, 0)) <0)
DieWithError("recv() failed");
}
closesocket(clientSocket); // close client socket
}
How can I fix this?
