+
−/**
+
− * test/demos/ddos/server.c
+
− * Copyright (C) 2008 Markus Broeker
+
− */
+
−
+
−#include <stdio.h>
+
−#include <stdlib.h>
+
−#include <string.h>
+
−#include <unistd.h>
+
−#include <sys/socket.h>
+
−#include <netinet/in.h>
+
−#include <arpa/inet.h>
+
−#include <sys/types.h>
+
−#include <signal.h>
+
−
+
−int set_proc_limit (int);
+
−
+
−int main (int argc, char **argv)
+
−{
+
−    char message[81];
+
−    int server_socket;
+
−    int client_socket;
+
−    struct sockaddr_in sa;
+
−    struct sockaddr_in ca;
+
−    socklen_t size;
+
−    int len;
+
−    int status;
+
−    pid_t pid;
+
−    pid_t parent_pid;
+
−
+
−    server_socket = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
+
−    if (server_socket == -1) {
+
−        perror ("socket");
+
−        return EXIT_FAILURE;
+
−    }
+
−
+
−    sa.sin_family = AF_INET;
+
−    sa.sin_port = htons (4000);
+
−    sa.sin_addr.s_addr = INADDR_ANY;
+
−
+
−    size = sizeof (sa);
+
−
+
−    status = bind (server_socket, (struct sockaddr *)&sa, size);
+
−    if (status != 0) {
+
−        perror ("BIND");
+
−        return EXIT_FAILURE;
+
−    }
+
−
+
−    status = listen (server_socket, 10);
+
−    if (status != 0) {
+
−        perror ("LISTEN");
+
−        return EXIT_FAILURE;
+
−    }
+
−
+
−    int links = 0;
+
−
+
−    parent_pid = getpid ();
+
−
+
−    /*
+
−     * Child quits immediately, father mustn't wait
+
−     */
+
−    signal (SIGCHLD, SIG_IGN);
+
−
+
−    if (set_proc_limit (200) != 0) {
+
−        printf ("Cannot limit the process limit\n");
+
−        return EXIT_FAILURE;
+
−    }
+
−
+
−    for (;;) {
+
−        size = sizeof (ca);
+
−        client_socket = accept (server_socket, (struct sockaddr *)&sa, (socklen_t *) & size);
+
−
+
−        printf ("PARENT PID = %d\n", parent_pid);
+
−
+
−        pid = fork ();
+
−        switch (pid) {
+
−        case 0:                /* Child */
+
−            close (server_socket);
+
−            if ((len = read (client_socket, message, 80)) == -1)
+
−                break;
+
−            message[len] = 0;
+
−
+
−            len = write (client_socket, "Please wait...\r\n", 17);
+
−            sleep (10);
+
−
+
−            printf ("DELETING LINK [%04d] %04d\n", getpid (), links--);
+
−            shutdown (client_socket, SHUT_RDWR);
+
−            close (client_socket);
+
−            return 1;
+
−        case -1:
+
−            perror ("Fork Error");
+
−            close (client_socket);
+
−            /*
+
−             * server is still alive and will continue
+
−             * * when resources are available
+
−             */
+
−            break;
+
−        default:               /* PID > 0 */
+
−            close (client_socket);
+
−            printf ("Starting LINK [%04d] %04d\n", pid, links++);
+
−        }
+
−    }
+
−
+
−    return close (server_socket);
+
−}