Basic implementation of HTTP Server in C

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <err.h>

#define DEFAULT_BUFLEN 1024
#define DEFAULT_PORT 80

char response[] =  "HTTP/1.1 200 OK\r\n"
"Server: LDServer\r\n"
"Last-Modified: Tue, 1 Dec 2015 19:15:56 GMT\r\n"
"Vary: Accept-Encoding\r\n"
"Content-Type: text/plain\r\n\r\n"
"By LukicDarkoo :)\r\n";

int main() {
    struct sockaddr_in server_address;
    struct sockaddr_in client_address;
    int client_socket;
    int server_socket = socket(AF_INET, SOCK_STREAM, 0);

    // Check if connection is established
    if (server_socket == -1) {
        err(1, "Can't open socket");
    }

    // Define socket & bind
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = INADDR_ANY;
    server_address.sin_port = htons(DEFAULT_PORT);

    if (bind(server_socket, (struct sockaddr *)&server_address, sizeof(server_address)) == -1) {
        err(1, "Can't bind socket");
    }

    // Listen for connections
    listen(server_socket, 3);


    // Connect to client
    puts("Listening...");
    int client_address_size = sizeof(client_address);
    client_socket = accept(server_socket, (struct sockaddr *)&client_address, (socklen_t *)&client_address_size);
    if (client_socket < 0) {
        err(1, "Can't accept connection");
    }

    write(client_socket, response, sizeof(response) - 1);

    // Read message from client
    puts("Reading answer...");
    char message[DEFAULT_BUFLEN];
    int message_size = 0;
    while (1) {
        message_size = recv(client_socket, message, DEFAULT_BUFLEN, 0);
        message[message_size] = 0;
        if (message_size > 0) {
            printf("%s", message);
            break;
        }
    }

    puts("Closing client and socket...");
    close(client_socket);
    close(server_socket);


    return 0;
}