/*
 * server_backend.c - network server socketing backend
 *
 * (c) 2001 Ondrej Jombik <nepto@pobox.sk>
 *
 * History
 * - 19/9/2001 - initial release
 * - 20/9/2001 - minor bugfixes
 *             - waitpid() used as substitute of wait()
 * - 24/9/2001 - fork() after accept() change (parent <-> child)
 *             - fnctl() removed
 *
 * TODO
 * - write debug infomations to STDERR
 * - ability to enter fake command on command line
 */

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>

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

/* wait() */
#include <sys/wait.h>

/* struct timeval */
#include <sys/time.h>

/* signal() */
#include <signal.h>

#include "utils.h"
#include "server-backend.h"

int main(int argc, char *argv[])
{
	register int cur_arg;
	int port, f_interactive = 0;
	int listen_sock;
	char **process;

	if (argc < 3) {
		fprintf(stderr, "Usage:\n"
				"  %s <port> <process> <arg1> ... <argN>\n"
				"  %s -i <port>\n",
				PROG_NAME, PROG_NAME);
		return 1;
	}

	cur_arg = 1;
	if (! strcmp(argv[cur_arg], "-i")) {
		f_interactive = 1;
		cur_arg++;
	}

	port = get_port(argv[cur_arg]);
	cur_arg++;

	if (f_interactive && 0) {
		process = NULL;
	} else {
		if ((process = create_process_array(argc, argv, cur_arg)) == NULL) {
			perror(PROG_NAME);
			return 32;
		}
	}

	fake_command_line(argc, argv);

	if ((listen_sock = bind_to_port(port)) == -1) {
		perror(PROG_NAME);
		return 16;
	}

	if (1) {
		(void) setpgrp();
		signal(SIGHUP, SIG_IGN);
	}

	if (0)
		fcntl(listen_sock,F_SETFL,O_NDELAY);

	switch (f_interactive ? 1 : fork()) {
		case -1:
			perror(PROG_NAME);
			return errno;
			break;
		case 0:
			break;
		default:
			fprintf(stderr, "%s: accepting connections on port %d\n",
					PROG_NAME, port);
			if (f_interactive)
				fprintf(stderr, "%s: interactive mode enabled,"
						" waiting for first client\n", PROG_NAME);
			else
				return 0;
			break;
	}

	while (1) {
		struct sockaddr_in acc_addr;
		unsigned int size;
		int accept_sock;

		sleep(1);

		size        = sizeof(struct sockaddr_in);
		accept_sock = accept(listen_sock, (struct sockaddr*) &acc_addr, &size);

		if (accept_sock < 0) {
			perror(PROG_NAME);
			return errno;
		}

		if (f_interactive) {
			fprintf(stderr, "%s: new client connected from %s\n",
					PROG_NAME, (char*)inet_ntoa(acc_addr.sin_addr));
			fprintf(stderr, "%s: you can now communicate via socket no. %d\n",
					PROG_NAME, accept_sock);
		}

		if (accept_sock > 0) {

			switch (f_interactive ? 1 : fork()) {
				case -1:
					perror(PROG_NAME);
					return errno;
					break;
				case 0: /* child */
					close(accept_sock);
					break;
				default: /* parent */
					if (! f_interactive) {
						dup2(accept_sock, 0);
						dup2(accept_sock, 1);
						dup2(accept_sock, 2);
						close(listen_sock);
						close(accept_sock);
						execvp(process[0], process);
						write(accept_sock, "execlp() failure\n\r", 18);
						return 8;
					}

					if (do_interactive(accept_sock) < 0) {
						perror(PROG_NAME);
						return 8;
					}
					return 0;
			}
		}

	} /* while (1) */

	return 0;
}