Server Socket errno 57 - Socket is not connected

Question

For some reason i am getting error an 57 - socket is not connected.

Why?

Console output:

GET / HTTP/1.1
Host: localhost:8080
Connection: keep-alive
Cache-Control: max-age=0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/33.0.1750.117 Safari/537.36
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8,it;q=0.6,lt;q=0.4,nl;q=0.2,ru;q=0.2

Can't write to socket 57

The code:

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#include <errno.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PORT 8080
#define PROTOCOL 0
#define BACKLOG 10
#define BUFLEN 1500

void str_server(int sock) 
{ 
  char buf[1025]; 
  const char* filename = "index.html"; 
  FILE *file = fopen(filename, "rb"); 
  if (!file)
    {
      printf("Can't open file for reading"); 
      return;
    }
  while (!feof(file)) 
    { 
      int rval = fread(buf, 1, sizeof(buf), file); 
      if (rval < 1)
        {
      printf("Can't read from file");
      fclose(file);
      return;
        }

      int off = 0;
        do
      {
            int sent = send(sock, &buf[off], rval - off, 0);
            if (sent < 1)
          {
                printf("Can't write to socket %d", errno);
                fclose(file);
                return;
          }

            off += sent;
      }
        while (off < rval);
    } 

  fclose(file);
} 

int main()
{
  int fd;
  int connfd;

  // For bind()
  struct sockaddr_in addr; 

  // For accept()
  struct sockaddr_in cliaddr; 
  socklen_t cliaddrlen = sizeof(cliaddr);

  // For reading and writing
  ssize_t i;
  ssize_t rcount;
  char buffer[BUFLEN];

  // Open a socket
  fd = socket(AF_INET, SOCK_STREAM, PROTOCOL);
  if (fd == -1) {
    printf("Error: unable to open a socket\n");
    printf("Error code: %d\n", errno);
    exit(1);
  }

  // Create an address
  //memset(&addr, 0, sizeof addr);
  addr.sin_addr.s_addr = INADDR_ANY;
  addr.sin_family = AF_INET;
  addr.sin_port = htons(PORT);

  int yes = 1;
  if ( setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1 )
  {
      perror("setsockopt");
  }

  if ((bind(fd, (struct sockaddr *)&addr, sizeof(addr))) == -1) {
    printf("Error: unable to bind\n");
    printf("Error code: %d\n", errno);
    exit(1);
  }

  // List for connections
  if ((listen(fd, BACKLOG)) == -1) {
    printf("Error: unable to listen for connections\n");
    printf("Error code: %d\n", errno);
    exit(1);
  }

  // Accept connections
  connfd = accept(fd, (struct sockaddr *) &cliaddr, &cliaddrlen);
  if (connfd == -1) {
    printf("Error: unable to accept connections\n");
    printf("Error code: %d\n", errno);
    exit(1);
  }

  // Read data
  rcount = read(connfd, buffer, BUFLEN);
  if (rcount == -1) {    
    printf("Error: unable to accept connections\n");
    printf("Error code: %d\n", errno);
    exit(1);
  }

  for (i = 0; i < rcount; i++) {
    printf("%c", buffer[i]);
  }

  //write(connfd, buffer, rcount);
  str_server(fd);


  // Bye
  //close(connfd);
  return 0;
}

Answer 1

You're sending to the listening socket, when you should be sending to the accepted/connected one.

To fix this pass the connected socket:

  str_server(connfd);