TCPWebServer-timeout.c

#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include "Practical.h"

int main(int argc, char *argv[]) {

  if (argc != 2) // Test for correct number of arguments
    DieWithUserMessage("Parameter(s)", "<Server Port/Service>");

  char *service = argv[1]; // First arg:  local port

  // Create socket for incoming connections
  int servSock = SetupTCPServerSocket(service);
  if (servSock < 0)
    DieWithUserMessage("SetupTCPServerSocket() failed", service);

  for (;;) { // Run forever
    // New connection creates a connected client socket
    int clntSock = AcceptTCPConnection(servSock);

    struct timeval timeout;
    timeout.tv_sec = 3;
    timeout.tv_usec = 0;

    if (setsockopt(clntSock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout,
    		   sizeof(timeout)) < 0)
    {
    	DieWithUserMessage("setsockopt", "SO_RCVTIMEO");
    }

    if (setsockopt(clntSock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout,
    		   sizeof(timeout)) < 0)
    {
    	DieWithUserMessage("setsockopt", "SO_SNDTIMEO");
    }

    HandleTCPClient(clntSock); // Process client
    close(clntSock);
  }
  // NOT REACHED
  close(servSock);
}

void HandleTCPClient(int clntSocket) {
  char buffer[BUFSIZE]; // Buffer for incoming request
  memset(buffer, 0, BUFSIZE);

  // Receive part of the request from the client
  ssize_t numBytesRcvd = recv(clntSocket, buffer, BUFSIZE, 0);

  if (numBytesRcvd < 0 && errno == EWOULDBLOCK) {
  	printf("closing socket due to timeout\n");
	close(clntSocket);
	return;
  }

  if (numBytesRcvd < 0)
    DieWithSystemMessage("recv() failed");

  // Send received string and receive again until end of stream
  while (numBytesRcvd > 0) { // 0 indicates end of stream
  	printf("%s", buffer);

    // See if there is more data to receive
	memset(buffer, 0, BUFSIZE);
    numBytesRcvd = recv(clntSocket, buffer, BUFSIZE, 0);

    if (numBytesRcvd < 0 && errno == EWOULDBLOCK) {
	  printf("closing socket due to timeout\n");
	  close(clntSocket);
	  return;
    }

    if (numBytesRcvd < 0)
      DieWithSystemMessage("recv() failed");
  }

  close(clntSocket); // Close client socket
}