/*
    tincd.c -- the main file for tincd
    Copyright (C) 1998-2002 Ivo Timmermans <ivo@o2w.nl>
                  2000-2002 Guus Sliepen <guus@sliepen.eu.org>

    This program 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 2 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    $Id: tincd.c,v 1.10.4.64 2002/09/15 12:26:04 guus Exp $
*/

#include "config.h"

#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <stdio.h>
#include <sys/types.h>
#include <syslog.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <termios.h>

/* Darwin (MacOS/X) needs the following definition... */
#ifndef _P1003_1B_VISIBLE
#define _P1003_1B_VISIBLE
#endif

#include <sys/mman.h>

#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif

#include <openssl/rand.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>
#include <openssl/evp.h>

#include <utils.h>
#include <xalloc.h>

#include "conf.h"
#include "net.h"
#include "netutl.h"
#include "process.h"
#include "protocol.h"
#include "subnet.h"

#include "system.h"

/* The name this program was run with. */
char *program_name;

/* If nonzero, display usage information and exit. */
int show_help;

/* If nonzero, print the version on standard output and exit.  */
int show_version;

/* If nonzero, it will attempt to kill a running tincd and exit. */
int kill_tincd = 0;

/* If nonzero, generate public/private keypair for this host/net. */
int generate_keys = 0;

/* If nonzero, use null ciphers and skip all key exchanges. */
int bypass_security = 0;

/* If nonzero, disable swapping for this process. */
int do_mlock = 0;

char *identname;				/* program name for syslog */
char *pidfilename;				/* pid file location */
char **g_argv;					/* a copy of the cmdline arguments */
char **environment;				/* A pointer to the environment on
								   startup */

static struct option const long_options[] = {
	{"config", required_argument, NULL, 'c'},
	{"kill", optional_argument, NULL, 'k'},
	{"net", required_argument, NULL, 'n'},
	{"help", no_argument, &show_help, 1},
	{"version", no_argument, &show_version, 1},
	{"no-detach", no_argument, &do_detach, 0},
	{"generate-keys", optional_argument, NULL, 'K'},
	{"debug", optional_argument, NULL, 'd'},
	{"bypass-security", no_argument, &bypass_security, 1},
	{"mlock", no_argument, &do_mlock, 1},
	{NULL, 0, NULL, 0}
};

static void usage(int status)
{
	if(status != 0)
		fprintf(stderr, _("Try `%s --help\' for more information.\n"),
				program_name);
	else {
		printf(_("Usage: %s [option]...\n\n"), program_name);
		printf(_
			   ("  -c, --config=DIR           Read configuration options from DIR.\n"
				"  -D, --no-detach            Don't fork and detach.\n"
				"  -d, --debug[=LEVEL]        Increase debug level or set it to LEVEL.\n"
				"  -k, --kill[=SIGNAL]        Attempt to kill a running tincd and exit.\n"
				"  -n, --net=NETNAME          Connect to net NETNAME.\n"
				"  -K, --generate-keys[=BITS] Generate public/private RSA keypair.\n"
				"  -L, --mlock                Lock tinc into main memory.\n"
				"      --help                 Display this help and exit.\n"
				"      --version              Output version information and exit.\n\n"));
		printf(_("Report bugs to tinc@nl.linux.org.\n"));
	}

	exit(status);
}

void parse_options(int argc, char **argv, char **envp)
{
	int r;
	int option_index = 0;

	while((r = getopt_long(argc, argv, "c:DLd::k::n:K::", long_options, &option_index)) != EOF) {
		switch (r) {
			case 0:				/* long option */
				break;

			case 'c':				/* config file */
				confbase = xmalloc(strlen(optarg) + 1);
				strcpy(confbase, optarg);
				break;

			case 'D':				/* no detach */
				do_detach = 0;
				break;

			case 'L':				/* no detach */
				do_mlock = 1;
				break;

			case 'd':				/* inc debug level */
				if(optarg)
					debug_lvl = atoi(optarg);
				else
					debug_lvl++;
				break;

			case 'k':				/* kill old tincds */
				if(optarg) {
					if(!strcasecmp(optarg, "HUP"))
						kill_tincd = SIGHUP;
					else if(!strcasecmp(optarg, "TERM"))
						kill_tincd = SIGTERM;
					else if(!strcasecmp(optarg, "KILL"))
						kill_tincd = SIGKILL;
					else if(!strcasecmp(optarg, "USR1"))
						kill_tincd = SIGUSR1;
					else if(!strcasecmp(optarg, "USR2"))
						kill_tincd = SIGUSR2;
					else if(!strcasecmp(optarg, "WINCH"))
						kill_tincd = SIGWINCH;
					else if(!strcasecmp(optarg, "INT"))
						kill_tincd = SIGINT;
					else if(!strcasecmp(optarg, "ALRM"))
						kill_tincd = SIGALRM;
					else {
						kill_tincd = atoi(optarg);

						if(!kill_tincd) {
							fprintf(stderr,
									_
									("Invalid argument `%s'; SIGNAL must be a number or one of HUP, TERM, KILL, USR1, USR2, WINCH, INT or ALRM.\n"),
									optarg);
							usage(1);
						}
					}
				} else
					kill_tincd = SIGTERM;
				break;

			case 'n':				/* net name given */
				netname = xmalloc(strlen(optarg) + 1);
				strcpy(netname, optarg);
				break;

			case 'K':				/* generate public/private keypair */
				if(optarg) {
					generate_keys = atoi(optarg);

					if(generate_keys < 512) {
						fprintf(stderr,
								_
								("Invalid argument `%s'; BITS must be a number equal to or greater than 512.\n"),
								optarg);
						usage(1);
					}

					generate_keys &= ~7;	/* Round it to bytes */
				} else
					generate_keys = 1024;
				break;

			case '?':
				usage(1);

			default:
				break;
		}
	}
}

/* This function prettyprints the key generation process */

void indicator(int a, int b, void *p)
{
	switch (a) {
		case 0:
			fprintf(stderr, ".");
			break;

		case 1:
			fprintf(stderr, "+");
			break;

		case 2:
			fprintf(stderr, "-");
			break;

		case 3:
			switch (b) {
				case 0:
					fprintf(stderr, " p\n");
					break;

				case 1:
					fprintf(stderr, " q\n");
					break;

				default:
					fprintf(stderr, "?");
			}
			break;

		default:
			fprintf(stderr, "?");
	}
}

/*
  Generate a public/private RSA keypair, and ask for a file to store
  them in.
*/
int keygen(int bits)
{
	RSA *rsa_key;
	FILE *f;
	char *name = NULL;
	char *filename;

	fprintf(stderr, _("Generating %d bits keys:\n"), bits);
	rsa_key = RSA_generate_key(bits, 0xFFFF, indicator, NULL);

	if(!rsa_key) {
		fprintf(stderr, _("Error during key generation!\n"));
		return -1;
	} else
		fprintf(stderr, _("Done.\n"));

	get_config_string(lookup_config(config_tree, "Name"), &name);

	if(name)
		asprintf(&filename, "%s/hosts/%s", confbase, name);
	else
		asprintf(&filename, "%s/rsa_key.pub", confbase);

	f = ask_and_safe_open(filename, _("public RSA key"), "a");

	if(!f)
		return -1;

	if(ftell(f))
		fprintf(stderr, _("Appending key to existing contents.\nMake sure only one key is stored in the file.\n"));

	PEM_write_RSAPublicKey(f, rsa_key);
	fclose(f);
	free(filename);

	asprintf(&filename, "%s/rsa_key.priv", confbase);
	f = ask_and_safe_open(filename, _("private RSA key"), "a");

	if(!f)
		return -1;

	if(ftell(f))
		fprintf(stderr, _("Appending key to existing contents.\nMake sure only one key is stored in the file.\n"));

	PEM_write_RSAPrivateKey(f, rsa_key, NULL, NULL, 0, NULL, NULL);
	fclose(f);
	free(filename);

	return 0;
}

/*
  Set all files and paths according to netname
*/
void make_names(void)
{
	if(netname) {
		if(!pidfilename)
			asprintf(&pidfilename, LOCALSTATEDIR "/run/tinc.%s.pid", netname);

		if(!confbase)
			asprintf(&confbase, "%s/tinc/%s", CONFDIR, netname);
		else
			syslog(LOG_INFO, _("Both netname and configuration directory given, using the latter..."));

		if(!identname)
			asprintf(&identname, "tinc.%s", netname);
	} else {
		if(!pidfilename)
			pidfilename = LOCALSTATEDIR "/run/tinc.pid";

		if(!confbase)
			asprintf(&confbase, "%s/tinc", CONFDIR);

		if(!identname)
			identname = "tinc";
	}
}

int main(int argc, char **argv, char **envp)
{
	program_name = argv[0];

	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);

	environment = envp;
	parse_options(argc, argv, envp);

	if(show_version) {
		printf(_("%s version %s (built %s %s, protocol %d)\n"), PACKAGE,
			   VERSION, __DATE__, __TIME__, PROT_CURRENT);
		printf(_("Copyright (C) 1998-2002 Ivo Timmermans, Guus Sliepen and others.\n"
				"See the AUTHORS file for a complete list.\n\n"
				"tinc comes with ABSOLUTELY NO WARRANTY.  This is free software,\n"
				"and you are welcome to redistribute it under certain conditions;\n"
				"see the file COPYING for details.\n"));

		return 0;
	}

	if(show_help)
		usage(0);

#ifndef LOG_PERROR
	openlog("tinc", LOG_CONS, LOG_DAEMON);	/* Catch all syslog() calls issued before detaching */
#else
	openlog("tinc", LOG_PERROR, LOG_DAEMON);	/* Catch all syslog() calls issued before detaching */
#endif

	/* Lock all pages into memory if requested */

	if(do_mlock)
#ifdef HAVE_MLOCKALL
		if(mlockall(MCL_CURRENT | MCL_FUTURE)) {
			syslog(LOG_ERR, _("System call `%s' failed: %s"), "mlockall",
				   strerror(errno));
#else
	{
		syslog(LOG_ERR, _("mlockall() not supported on this platform!"));
#endif
		return -1;
	}

	g_argv = argv;

	make_names();
	init_configuration(&config_tree);

	/* Slllluuuuuuurrrrp! */

	RAND_load_file("/dev/urandom", 1024);

#ifdef HAVE_SSLEAY_ADD_ALL_ALGORITHMS
	SSLeay_add_all_algorithms();
#else
	OpenSSL_add_all_algorithms();
#endif

	if(generate_keys) {
		read_server_config();
		exit(keygen(generate_keys));
	}

	if(kill_tincd)
		exit(kill_other(kill_tincd));

	if(read_server_config())
		exit(1);

	if(detach())
		exit(0);

	for(;;) {
		if(!setup_network_connections()) {
			main_loop();
			cleanup_and_exit(1);
		}

		syslog(LOG_ERR, _("Unrecoverable error"));
		cp_trace();

		if(do_detach) {
			syslog(LOG_NOTICE, _("Restarting in %d seconds!"), maxtimeout);
			sleep(maxtimeout);
		} else {
			syslog(LOG_ERR, _("Not restarting."));
			exit(1);
		}
	}
}