/*
 * Copyright (C) 2015 Nikos Mavrogiannopoulos
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * GnuTLS is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuTLS is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GnuTLS; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

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

#if defined(_WIN32) || !defined(HAVE_LIBSECCOMP)

int main()
{
	exit(77);
}

#else

#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <signal.h>
#include <assert.h>
#include <gnutls/gnutls.h>
#include <gnutls/dtls.h>

#include "cert-common.h"
#include "utils.h"

static void terminate(void);

static void server_log_func(int level, const char *str)
{
	fprintf(stderr, "server|<%d>| %s", level, str);
}

static void client_log_func(int level, const char *str)
{
	fprintf(stderr, "client|<%d>| %s", level, str);
}

#define MAX_BUF 1024

static ssize_t
push(gnutls_transport_ptr_t tr, const void *data, size_t len)
{
	int fd = (long int) tr;

	return send(fd, data, len, 0);
}

static void client(int fd, const char *prio)
{
	int ret;
	char buffer[MAX_BUF + 1];
	gnutls_certificate_credentials_t xcred;
	gnutls_session_t session;

	global_init();

	if (debug) {
		gnutls_global_set_log_function(client_log_func);
		gnutls_global_set_log_level(4711);
	}

	gnutls_certificate_allocate_credentials(&xcred);

	/* Initialize TLS session
	 */
	gnutls_init(&session, GNUTLS_CLIENT | GNUTLS_DATAGRAM);
	gnutls_dtls_set_mtu(session, 1500);
	gnutls_handshake_set_timeout(session, 20 * 1000);

	assert(gnutls_priority_set_direct(session, prio, NULL) >= 0);

	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);

	gnutls_transport_set_int(session, fd);
	gnutls_transport_set_push_function(session, push);

	/* Perform the TLS handshake
	 */
	do {
		ret = gnutls_handshake(session);
	}
	while (ret < 0 && gnutls_error_is_fatal(ret) == 0);

	if (ret < 0) {
		fail("client: Handshake failed\n");
		gnutls_perror(ret);
		exit(1);
	} else {
		if (debug)
			success("client: Handshake was completed\n");
	}

	if (debug)
		success("client: TLS version is: %s\n",
			gnutls_protocol_get_name
			(gnutls_protocol_get_version(session)));

	do {
		ret = gnutls_record_recv(session, buffer, sizeof(buffer)-1);
	} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);

	if (ret == 0) {
		if (debug)
			success
			    ("client: Peer has closed the TLS connection\n");
		goto end;
	} else if (ret < 0) {
		fail("client: Error: %s\n", gnutls_strerror(ret));
		exit(1);
	}

	ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
	if (ret < 0) {
		fail("server: error in closing session: %s\n", gnutls_strerror(ret));
	}

      end:

	close(fd);

	gnutls_deinit(session);

	gnutls_certificate_free_credentials(xcred);

	gnutls_global_deinit();
}


/* These are global */
pid_t child;

static void terminate(void)
{
	int status;

	kill(child, SIGTERM);
	wait(&status);
	exit(1);
}

static void server(int fd, const char *prio)
{
	int ret;
	gnutls_certificate_credentials_t xcred;
	char buffer[MAX_BUF + 1];
	gnutls_session_t session;

	/* this must be called once in the program
	 */
	global_init();

	if (debug) {
		gnutls_global_set_log_function(server_log_func);
		gnutls_global_set_log_level(4711);
	}

	gnutls_certificate_allocate_credentials(&xcred);

	ret = gnutls_certificate_set_x509_key_mem(xcred,
					    &server_cert, &server_key,
					    GNUTLS_X509_FMT_PEM);
	if (ret < 0)
		exit(1);

	ret = disable_system_calls();
	if (ret < 0) {
		fprintf(stderr, "could not enable seccomp\n");
		exit(2);
	}

	gnutls_init(&session, GNUTLS_SERVER | GNUTLS_DATAGRAM);
	gnutls_handshake_set_timeout(session, 20 * 1000);
	gnutls_dtls_set_mtu(session, 1500);

	assert(gnutls_priority_set_direct(session, prio, NULL) >= 0);

	gnutls_credentials_set(session, GNUTLS_CRD_CERTIFICATE, xcred);

	gnutls_transport_set_int(session, fd);
	gnutls_transport_set_push_function(session, push);

	do {
		ret = gnutls_handshake(session);
	}
	while (ret < 0 && gnutls_error_is_fatal(ret) == 0);
	if (ret < 0) {
		close(fd);
		gnutls_deinit(session);
		fail("server: Handshake has failed (%s)\n\n",
		     gnutls_strerror(ret));
		terminate();
	}
	if (debug)
		success("server: Handshake was completed\n");

	if (debug)
		success("server: TLS version is: %s\n",
			gnutls_protocol_get_name
			(gnutls_protocol_get_version(session)));

	/* see the Getting peer's information example */
	/* print_info(session); */

	memset(buffer, 1, sizeof(buffer));
	do {
		ret = gnutls_record_send(session, buffer, sizeof(buffer)-1);
	} while (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED);

	if (ret < 0) {
		close(fd);
		gnutls_deinit(session);
		fail("server: data sending has failed (%s)\n\n",
		     gnutls_strerror(ret));
		terminate();
	}

	ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
	if (ret < 0) {
		fail("server: error in closing session: %s\n", gnutls_strerror(ret));
	}

	close(fd);
	gnutls_deinit(session);

	gnutls_certificate_free_credentials(xcred);

	gnutls_global_deinit();

	if (debug)
		success("server: finished\n");
}

static 
void run(const char *name, const char *prio)
{
	int fd[2];
	int ret;

	success("trying: %s\n", name);
	signal(SIGPIPE, SIG_IGN);

	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
	if (ret < 0) {
		perror("socketpair");
		exit(1);
	}

	child = fork();
	if (child < 0) {
		perror("fork");
		fail("fork");
		exit(1);
	}

	if (child) {
		int status;
		/* parent */

		close(fd[0]);
		client(fd[1], prio);

		wait(&status);
		check_wait_status(status);
	} else {
		close(fd[1]);
		server(fd[0], prio);
		exit(0);
	}
}

void doit(void)
{
	run("dtls1.0", "NORMAL:-KX-ALL:+ECDHE-RSA:-VERS-ALL:+VERS-DTLS1.0");
	run("dtls1.2", "NORMAL:-KX-ALL:+ECDHE-RSA:-VERS-ALL:+VERS-DTLS1.2");
	run("default", "NORMAL");
}


#endif				/* _WIN32 */