Saturday, July 6, 2013

A Simple Server in C++

Makefile


default:
 g++ server.cpp
 ./a.out
clean:
 rm -f a.out

server.cpp


//
//  server.cpp
//  SimpleServer
//
//  Created by Kurry Tran on 7/3/13.
//  Copyright (c) 2013 Kurry Tran. All rights reserved.
//

#include <iostream>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <pthread.h>
#include <netdb.h>

void* SocketHandler(void*);

int main(int argc, const char * argv[])
{
    int host_port= 1101;
 struct sockaddr_in my_addr;
 int hsock;
 int *p_int;
    
 socklen_t addr_size = 0;
 int* csock;
 sockaddr_in sadr;
 pthread_t thread_id=0;
    
 hsock = socket(AF_INET, SOCK_STREAM, 0);
 if(hsock == -1){
        std::cout <<"Error initializing socket " << errno << std::endl;
  goto FINISH;
 }
 p_int = (int*)malloc(sizeof(int));
 *p_int = 1;
    
 if( (setsockopt(hsock, SOL_SOCKET, SO_REUSEADDR, (char*)p_int, sizeof(int)) == -1 )||
       (setsockopt(hsock, SOL_SOCKET, SO_KEEPALIVE, (char*)p_int, sizeof(int)) == -1 ) ){
        std::cout <<"Error setting options " << errno << std::endl;
  free(p_int);
  goto FINISH;
 }
 free(p_int);
    
 my_addr.sin_family = AF_INET ;
 my_addr.sin_port = htons(host_port);
 
 memset(&(my_addr.sin_zero), 0, 8);
 my_addr.sin_addr.s_addr = INADDR_ANY ;
 
 if( bind( hsock, (sockaddr*)&my_addr, sizeof(my_addr)) == -1 ){
        std::cerr << "Error binding to socket, make sure nothing else is listening on this port " << errno << std::endl;
  goto FINISH;
 }
    
 if(listen( hsock, 10) == -1 ){
        std::cerr << "Error listening " << errno << std::endl;
  goto FINISH;
 }
    
 addr_size = sizeof(sockaddr_in);
 
 while(true){
        std::cout <<"waiting for a connection on localhost:"<<host_port<< std::endl;
  csock = (int*)malloc(sizeof(int));
  if((*csock = accept( hsock, (sockaddr*)&sadr, &addr_size))!= -1){
            std::cout <<"---------------------\nReceived connection from "<< inet_ntoa(sadr.sin_addr) << std::endl;
   pthread_create(&thread_id,0,&SocketHandler, (void*)csock );
   pthread_detach(thread_id);
  }
  else{
            std::cerr << "Error accepting " << errno << std::endl;
  }
 }
    
FINISH:
    ;
}

void *SocketHandler(void *lp){
    int *csock = (int *)lp;
    
 char buffer[1024];
 int buffer_len = 1024;
 ssize_t bytecount;
    
 memset(buffer, 0, buffer_len);
 if((bytecount = recv(*csock, buffer, buffer_len, 0))== -1){
        std::cerr << "Error receiving data " << errno << std::endl;
  goto FINISH;
 }
    std::cout << "Received bytes " << bytecount << std::endl << "Received string "<< buffer << std::endl;

 if((bytecount = send(*csock, buffer, strlen(buffer), 0))== -1){
        std::cerr << "Error sending data " << errno << std::endl;
  goto FINISH;
 } 
    std::cout << "Sent bytes " << bytecount << std::endl;
    
FINISH:
    close(*csock);
 free(csock);
    return 0;
}