/* Simple echo server
 * Jeff Turkstra, 2010
 */
#include <stdlib.h>
#include <stdio.h>
#include <arpa/inet.h>
#include <string.h>

int main(int argc, char *argv[]) {
  int me;
  int client;
  struct sockaddr_in my_addr; 
  struct sockaddr_in client_addr;
  int client_size;

  char buf[512];

  if (argc != 2) {
    printf("Usage: %s [port]\n", argv[0]);
    return -1;
  }

  me = socket(PF_INET, SOCK_STREAM, 0);
  if (me <= 0) {
    perror("socket");
    return -1;
  }

  memset(&my_addr, 0, sizeof(my_addr));
  my_addr.sin_family = AF_INET;
  my_addr.sin_addr.s_addr = htonl(INADDR_ANY);
  my_addr.sin_port = htons(atoi(argv[1]));

  if (bind(me, (struct sockaddr *) &my_addr, sizeof(my_addr)) < 0) {
    perror("bind");
    return -1;
  }

  if (listen(me, 1) < 0) {
    perror("listen");
    return -1;
  }

  client = 0;
  while (1) {
    client_size = sizeof(client_addr);

    if (!client) {
      client = accept(me, (struct sockaddr *) &client_addr, &client_size);
      if (client < 0) {
        perror("client");
        return -1;
      }
      else {
        printf("Connected to %s\n", inet_ntoa(client_addr.sin_addr));
      }
    }

    client_size = recv(client, buf, 1024, 0);
    if (client_size < 0) {
      perror("recv");
      return -1;
    }

    if (client_size == 1) return 0;

    if (send(client, buf, client_size, 0) < 0) {
      perror("send");
      return -1;
    }
    
  }

  return 0;
}