/*
    tincctl.c -- Controlling a running tincd
    Copyright (C) 2007-2012 Guus Sliepen <guus@tinc-vpn.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.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "system.h"

#include <getopt.h>

#include "xalloc.h"
#include "protocol.h"
#include "control_common.h"
#include "ecdsagen.h"
#include "rsagen.h"
#include "utils.h"
#include "tincctl.h"
#include "top.h"

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

/* If nonzero, display usage information and exit. */
static bool show_help = false;

/* If nonzero, print the version on standard output and exit.  */
static bool show_version = false;

static char *name = NULL;
static char *identname = NULL;				/* program name for syslog */
static char *pidfilename = NULL;			/* pid file location */
static char controlcookie[1024];
char *netname = NULL;
char *confbase = NULL;
static char *tinc_conf = NULL;
static char *hosts_dir = NULL;

// Horrible global variables...
static int pid = 0;
static int fd = -1;
static char line[4096];
static int code;
static int req;
static int result;

#ifdef HAVE_MINGW
static struct WSAData wsa_state;
#endif

static struct option const long_options[] = {
	{"config", required_argument, NULL, 'c'},
	{"debug", optional_argument, NULL, 0},
	{"no-detach", no_argument, NULL, 0},
	{"mlock", no_argument, NULL, 0},
	{"net", required_argument, NULL, 'n'},
	{"help", no_argument, NULL, 1},
	{"version", no_argument, NULL, 2},
	{"pidfile", required_argument, NULL, 5},
	{"logfile", required_argument, NULL, 0},
	{"bypass-security", no_argument, NULL, 0},
	{"chroot", no_argument, NULL, 0},
	{"user", required_argument, NULL, 0},
	{"option", required_argument, NULL, 0},
	{NULL, 0, NULL, 0}
};

static void version(void) {
	printf("%s version %s (built %s %s, protocol %d.%d)\n", PACKAGE,
		   VERSION, __DATE__, __TIME__, PROT_MAJOR, PROT_MINOR);
	printf("Copyright (C) 1998-2012 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");
}

static void usage(bool status) {
	if(status)
		fprintf(stderr, "Try `%s --help\' for more information.\n",
				program_name);
	else {
		printf("Usage: %s [options] command\n\n", program_name);
		printf("Valid options are:\n"
				"  -c, --config=DIR        Read configuration options from DIR.\n"
				"  -n, --net=NETNAME       Connect to net NETNAME.\n"
				"      --pidfile=FILENAME  Read control cookie from FILENAME.\n"
				"      --help              Display this help and exit.\n"
				"      --version           Output version information and exit.\n"
				"\n"
				"Valid commands are:\n"
				"  init [name]                Create initial configuration files.\n"
				"  config                     Change configuration:\n"
				"    [set] VARIABLE VALUE     - set VARIABLE to VALUE\n"
				"    add VARIABLE VALUE       - add VARIABLE with the given VALUE\n"
				"    del VARIABLE [VALUE]     - remove VARIABLE [only ones with watching VALUE]\n"
				"  start [tincd options]      Start tincd.\n"
				"  stop                       Stop tincd.\n"
				"  restart                    Restart tincd.\n"
				"  reload                     Partially reload configuration of running tincd.\n"
				"  pid                        Show PID of currently running tincd.\n"
				"  generate-keys [bits]       Generate new RSA and ECDSA public/private keypairs.\n"
				"  generate-rsa-keys [bits]   Generate a new RSA public/private keypair.\n"
				"  generate-ecdsa-keys        Generate a new ECDSA public/private keypair.\n"
				"  dump                       Dump a list of one of the following things:\n"
				"    nodes                    - all known nodes in the VPN\n"
				"    edges                    - all known connections in the VPN\n"
				"    subnets                  - all known subnets in the VPN\n"
				"    connections              - all meta connections with ourself\n"
				"    graph                    - graph of the VPN in dotty format\n"
				"  purge                      Purge unreachable nodes\n"
				"  debug N                    Set debug level\n"
				"  retry                      Retry all outgoing connections\n"
				"  disconnect NODE            Close meta connection with NODE\n"
#ifdef HAVE_CURSES
				"  top                        Show real-time statistics\n"
#endif
				"  pcap [snaplen]             Dump traffic in pcap format [up to snaplen bytes per packet]\n"
				"  log [level]                Dump log output [up to the specified level]\n"
				"\n");
		printf("Report bugs to tinc@tinc-vpn.org.\n");
	}
}

static bool parse_options(int argc, char **argv) {
	int r;
	int option_index = 0;

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

			case 'c':				/* config file */
				confbase = xstrdup(optarg);
				break;

			case 'n':				/* net name given */
				netname = xstrdup(optarg);
				break;

			case 1:					/* show help */
				show_help = true;
				break;

			case 2:					/* show version */
				show_version = true;
				break;

			case 5:					/* open control socket here */
				pidfilename = xstrdup(optarg);
				break;

			case '?':
				usage(true);
				return false;

			default:
				break;
		}
	}

	if(!netname) {
		netname = getenv("NETNAME");
		if(netname)
			netname = xstrdup(netname);
	}

	return true;
}

static FILE *ask_and_open(const char *filename, const char *what, const char *mode) {
	FILE *r;
	char *directory;
	char buf[PATH_MAX];
	char buf2[PATH_MAX];

	/* Check stdin and stdout */
	if(isatty(0) && isatty(1)) {
		/* Ask for a file and/or directory name. */
		fprintf(stdout, "Please enter a file to save %s to [%s]: ",
				what, filename);
		fflush(stdout);

		if(fgets(buf, sizeof buf, stdin) == NULL) {
			fprintf(stderr, "Error while reading stdin: %s\n",
					strerror(errno));
			return NULL;
		}

		size_t len = strlen(buf);
		if(len)
			buf[--len] = 0;

		if(len)
			filename = buf;
	}

#ifdef HAVE_MINGW
	if(filename[0] != '\\' && filename[0] != '/' && !strchr(filename, ':')) {
#else
	if(filename[0] != '/') {
#endif
		/* The directory is a relative path or a filename. */
		directory = get_current_dir_name();
		snprintf(buf2, sizeof buf2, "%s/%s", directory, filename);
		filename = buf2;
	}

	umask(0077);				/* Disallow everything for group and other */

	/* Open it first to keep the inode busy */

	r = fopen(filename, mode);

	if(!r) {
		fprintf(stderr, "Error opening file `%s': %s\n", filename, strerror(errno));
		return NULL;
	}

	return r;
}

/*
  Generate a public/private ECDSA keypair, and ask for a file to store
  them in.
*/
static bool ecdsa_keygen() {
	ecdsa_t key;
	FILE *f;
	char *filename;

	fprintf(stderr, "Generating ECDSA keypair:\n");

	if(!ecdsa_generate(&key)) {
		fprintf(stderr, "Error during key generation!\n");
		return false;
	} else
		fprintf(stderr, "Done.\n");

	xasprintf(&filename, "%s/ecdsa_key.priv", confbase);
	f = ask_and_open(filename, "private ECDSA key", "a");

	if(!f)
		return false;
  
#ifdef HAVE_FCHMOD
	/* Make it unreadable for others. */
	fchmod(fileno(f), 0600);
#endif
		
	if(ftell(f))
		fprintf(stderr, "Appending key to existing contents.\nMake sure only one key is stored in the file.\n");

	ecdsa_write_pem_private_key(&key, f);

	fclose(f);
	free(filename);

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

	f = ask_and_open(filename, "public ECDSA key", "a");

	if(!f)
		return false;

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

	char *pubkey = ecdsa_get_base64_public_key(&key);
	fprintf(f, "ECDSAPublicKey = %s\n", pubkey);
	free(pubkey);

	fclose(f);
	free(filename);

	return true;
}

/*
  Generate a public/private RSA keypair, and ask for a file to store
  them in.
*/
static bool rsa_keygen(int bits) {
	rsa_t key;
	FILE *f;
	char *filename;

	fprintf(stderr, "Generating %d bits keys:\n", bits);

	if(!rsa_generate(&key, bits, 0x10001)) {
		fprintf(stderr, "Error during key generation!\n");
		return false;
	} else
		fprintf(stderr, "Done.\n");

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

	if(!f)
		return false;
  
#ifdef HAVE_FCHMOD
	/* Make it unreadable for others. */
	fchmod(fileno(f), 0600);
#endif
		
	if(ftell(f))
		fprintf(stderr, "Appending key to existing contents.\nMake sure only one key is stored in the file.\n");

	rsa_write_pem_private_key(&key, f);

	fclose(f);
	free(filename);

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

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

	if(!f)
		return false;

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

	rsa_write_pem_public_key(&key, f);

	fclose(f);
	free(filename);

	return true;
}

/*
  Set all files and paths according to netname
*/
static void make_names(void) {
#ifdef HAVE_MINGW
	HKEY key;
	char installdir[1024] = "";
	long len = sizeof installdir;
#endif

	if(netname)
		xasprintf(&identname, "tinc.%s", netname);
	else
		identname = xstrdup("tinc");

#ifdef HAVE_MINGW
	if(!RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\tinc", 0, KEY_READ, &key)) {
		if(!RegQueryValueEx(key, NULL, 0, 0, installdir, &len)) {
			if(!confbase) {
				if(netname)
					xasprintf(&confbase, "%s/%s", installdir, netname);
				else
					xasprintf(&confbase, "%s", installdir);
			}
		}
		if(!pidfilename)
			xasprintf(&pidfilename, "%s/pid", confbase);
		RegCloseKey(key);
	}

	if(!*installdir) {
#endif

	if(!pidfilename)
		xasprintf(&pidfilename, "%s/run/%s.pid", LOCALSTATEDIR, identname);

	if(netname) {
		if(!confbase)
			xasprintf(&confbase, CONFDIR "/tinc/%s", netname);
		else
			fprintf(stderr, "Both netname and configuration directory given, using the latter...\n");
	} else {
		if(!confbase)
			xasprintf(&confbase, CONFDIR "/tinc");
	}

#ifdef HAVE_MINGW
	}
#endif

	xasprintf(&tinc_conf, "%s/tinc.conf", confbase);
	xasprintf(&hosts_dir, "%s/hosts", confbase);
}

static char buffer[4096];
static size_t blen = 0;

bool recvline(int fd, char *line, size_t len) {
	char *newline = NULL;

	while(!(newline = memchr(buffer, '\n', blen))) {
		int result = recv(fd, buffer + blen, sizeof buffer - blen, 0);
		if(result == -1 && errno == EINTR)
			continue;
		else if(result <= 0)
			return false;
		blen += result;
	}

	if(newline - buffer >= len)
		return false;

	len = newline - buffer;

	memcpy(line, buffer, len);
	line[len] = 0;
	memmove(buffer, newline + 1, blen - len - 1);
	blen -= len + 1;

	return true;
}

static bool recvdata(int fd, char *data, size_t len) {
	while(blen < len) {
		int result = recv(fd, buffer + blen, sizeof buffer - blen, 0);
		if(result == -1 && errno == EINTR)
			continue;
		else if(result <= 0)
			return false;
		blen += result;
	}

	memcpy(data, buffer, len);
	memmove(buffer, buffer + len, blen - len);
	blen -= len;

	return true;
}

bool sendline(int fd, char *format, ...) {
	static char buffer[4096];
	char *p = buffer;
	int blen = 0;
	va_list ap;

	va_start(ap, format);
	blen = vsnprintf(buffer, sizeof buffer, format, ap);
	va_end(ap);

	if(blen < 1 || blen >= sizeof buffer)
		return false;

	buffer[blen] = '\n';
	blen++;

	while(blen) {
		int result = send(fd, p, blen, 0);
		if(result == -1 && errno == EINTR)
			continue;
		else if(result <= 0)
			return false;
		p += result;
		blen -= result;
	}

	return true;	
}

static void pcap(int fd, FILE *out, int snaplen) {
	sendline(fd, "%d %d %d", CONTROL, REQ_PCAP, snaplen);
	char data[9018];

	struct {
		uint32_t magic;
		uint16_t major;
		uint16_t minor;
		uint32_t tz_offset;
		uint32_t tz_accuracy;
		uint32_t snaplen;
		uint32_t ll_type;
	} header = {
		0xa1b2c3d4,
		2, 4,
		0, 0,
		snaplen ?: sizeof data,
		1,
	};

	struct {
		uint32_t tv_sec;
		uint32_t tv_usec;
		uint32_t len;
		uint32_t origlen;
	} packet;

	struct timeval tv;

	fwrite(&header, sizeof header, 1, out);
	fflush(out);

	char line[32];
	while(recvline(fd, line, sizeof line)) {
		int code, req, len;
		int n = sscanf(line, "%d %d %d", &code, &req, &len);
		gettimeofday(&tv, NULL);
		if(n != 3 || code != CONTROL || req != REQ_PCAP || len < 0 || len > sizeof data)
			break;
		if(!recvdata(fd, data, len))
			break;
		packet.tv_sec = tv.tv_sec;
		packet.tv_usec = tv.tv_usec;
		packet.len = len;
		packet.origlen = len;
		fwrite(&packet, sizeof packet, 1, out);
		fwrite(data, len, 1, out);
		fflush(out);
	}
}

static void logcontrol(int fd, FILE *out, int level) {
	sendline(fd, "%d %d %d", CONTROL, REQ_LOG, level);
	char data[1024];
	char line[32];

	while(recvline(fd, line, sizeof line)) {
		int code, req, len;
		int n = sscanf(line, "%d %d %d", &code, &req, &len);
		if(n != 3 || code != CONTROL || req != REQ_LOG || len < 0 || len > sizeof data)
			break;
		if(!recvdata(fd, data, len))
			break;
		fwrite(data, len, 1, out);
		fputc('\n', out);
		fflush(out);
	}
}

#ifdef HAVE_MINGW
static bool remove_service(void) {
	SC_HANDLE manager = NULL;
	SC_HANDLE service = NULL;
	SERVICE_STATUS status = {0};

	manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS);
	if(!manager) {
		fprintf(stderr, "Could not open service manager: %s\n", winerror(GetLastError()));
		return false;
	}

	service = OpenService(manager, identname, SERVICE_ALL_ACCESS);

	if(!service) {
		fprintf(stderr, "Could not open %s service: %s\n", identname, winerror(GetLastError()));
		return false;
	}

	if(!ControlService(service, SERVICE_CONTROL_STOP, &status))
		fprintf(stderr, "Could not stop %s service: %s\n", identname, winerror(GetLastError()));
	else
		fprintf(stderr, "%s service stopped\n", identname);

	if(!DeleteService(service)) {
		fprintf(stderr, "Could not remove %s service: %s\n", identname, winerror(GetLastError()));
		return false;
	}

	fprintf(stderr, "%s service removed\n", identname);

	return true;
}
#endif

static bool connect_tincd() {
	if(fd >= 0)
		return true;

	FILE *f = fopen(pidfilename, "r");
	if(!f) {
		fprintf(stderr, "Could not open pid file %s: %s\n", pidfilename, strerror(errno));
		return false;
	}

	char host[128];
	char port[128];

	if(fscanf(f, "%20d %1024s %128s port %128s", &pid, controlcookie, host, port) != 4) {
		fprintf(stderr, "Could not parse pid file %s\n", pidfilename);
		return false;
	}

#ifdef HAVE_MINGW
	if(WSAStartup(MAKEWORD(2, 2), &wsa_state)) {
		fprintf(stderr, "System call `%s' failed: %s", "WSAStartup", winerror(GetLastError()));
		return false;
	}
#endif

	struct addrinfo hints = {
		.ai_family = AF_UNSPEC,
		.ai_socktype = SOCK_STREAM,
		.ai_protocol = IPPROTO_TCP,
		.ai_flags = 0,
	};

	struct addrinfo *res = NULL;

	if(getaddrinfo(host, port, &hints, &res) || !res) {
		fprintf(stderr, "Cannot resolve %s port %s: %s", host, port, strerror(errno));
		return false;
	}

	fd = socket(res->ai_family, SOCK_STREAM, IPPROTO_TCP);
	if(fd < 0) {
		fprintf(stderr, "Cannot create TCP socket: %s\n", sockstrerror(sockerrno));
		return false;
	}

#ifdef HAVE_MINGW
	unsigned long arg = 0;

	if(ioctlsocket(fd, FIONBIO, &arg) != 0) {
		fprintf(stderr, "ioctlsocket failed: %s", sockstrerror(sockerrno));
	}
#endif

	if(connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
		fprintf(stderr, "Cannot connect to %s port %s: %s\n", host, port, sockstrerror(sockerrno));
		return false;
	}

	freeaddrinfo(res);

	char data[4096];
	int version;

	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %s %d", &code, data, &version) != 3 || code != 0) {
		fprintf(stderr, "Cannot read greeting from control socket: %s\n", sockstrerror(sockerrno));
		return false;
	}

	sendline(fd, "%d ^%s %d", ID, controlcookie, TINC_CTL_VERSION_CURRENT);
	
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &version, &pid) != 3 || code != 4 || version != TINC_CTL_VERSION_CURRENT) {
		fprintf(stderr, "Could not fully establish control socket connection\n");
		return false;
	}

	return true;
}


static int cmd_start(int argc, char *argv[]) {
	int i, j;
	char *c;

	argc += optind;
	argv -= optind;
	char *slash = strrchr(argv[0], '/');

#ifdef HAVE_MINGW
	if ((c = strrchr(argv[0], '\\')) > slash)
		slash = c;
#endif

	if (slash++) {
		c = xmalloc((slash - argv[0]) + sizeof("tincd"));
		sprintf(c, "%.*stincd", (int)(slash - argv[0]), argv[0]);
	}
	else
		c = "tincd";

	argv[0] = c;

	for(i = j = 1; argv[i]; ++i)
		if (i != optind && strcmp(argv[i], "--") != 0)
			argv[j++] = argv[i];

	argv[j] = NULL;
	execvp(c, argv);
	fprintf(stderr, "Could not start %s: %s\n", c, strerror(errno));
	return 1;
}

static int cmd_stop(int argc, char *argv[]) {
#ifndef HAVE_MINGW
	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d", CONTROL, REQ_STOP);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_STOP || result) {
		fprintf(stderr, "Could not stop tinc daemon.\n");
		return 1;
	}
#else
	if(!remove_service())
		return 1;
#endif
	return 0;
}

static int cmd_restart(int argc, char *argv[]) {
	return cmd_stop(argc, argv) ?: cmd_start(argc, argv);
}

static int cmd_reload(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d", CONTROL, REQ_RELOAD);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_RELOAD || result) {
		fprintf(stderr, "Could not reload configuration.\n");
		return 1;
	}

	return 0;

}

static int cmd_dump(int argc, char *argv[]) {
	if(argc != 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		usage(true);
		return 1;
	}

	if(!connect_tincd())
		return 1;

	bool do_graph = false;

	if(!strcasecmp(argv[1], "nodes"))
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
	else if(!strcasecmp(argv[1], "edges"))
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_EDGES);
	else if(!strcasecmp(argv[1], "subnets"))
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_SUBNETS);
	else if(!strcasecmp(argv[1], "connections"))
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_CONNECTIONS);
	else if(!strcasecmp(argv[1], "graph")) {
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_NODES);
		sendline(fd, "%d %d", CONTROL, REQ_DUMP_EDGES);
		do_graph = true;
	} else {
		fprintf(stderr, "Unknown dump type '%s'.\n", argv[1]);
		usage(true);
		return 1;
	}

	if(do_graph)
		printf("digraph {\n");

	while(recvline(fd, line, sizeof line)) {
		char node1[4096], node2[4096];
		int n = sscanf(line, "%d %d %s to %s", &code, &req, node1, node2);
		if(n == 2) {
			if(do_graph && req == REQ_DUMP_NODES)
				continue;
			else {
				if(do_graph)
					printf("}\n");
				return 0;
			}
		}
		if(n < 2)
			break;

		if(!do_graph)
			printf("%s\n", line + 5);
		else {
			if(req == REQ_DUMP_NODES)
				printf(" %s [label = \"%s\"];\n", node1, node1);
			else
				printf(" %s -> %s;\n", node1, node2);
		}
	}

	fprintf(stderr, "Error receiving dump.\n");
	return 1;
}

static int cmd_purge(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d", CONTROL, REQ_PURGE);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_PURGE || result) {
		fprintf(stderr, "Could not purge old information.\n");
		return 1;
	}

	return 0;
}

static int cmd_debug(int argc, char *argv[]) {
	if(argc != 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	if(!connect_tincd())
		return 1;

	int debuglevel = atoi(argv[1]);
	int origlevel;

	sendline(fd, "%d %d %d", CONTROL, REQ_SET_DEBUG, debuglevel);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &origlevel) != 3 || code != CONTROL || req != REQ_SET_DEBUG) {
		fprintf(stderr, "Could not set debug level.\n");
		return 1;
	}

	fprintf(stderr, "Old level %d, new level %d.\n", origlevel, debuglevel);
	return 0;
}

static int cmd_retry(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d", CONTROL, REQ_RETRY);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_RETRY || result) {
		fprintf(stderr, "Could not retry outgoing connections.\n");
		return 1;
	}

	return 0;
}

static int cmd_connect(int argc, char *argv[]) {
	if(argc != 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	if(!check_id(argv[2])) {
		fprintf(stderr, "Invalid name for node.\n");
		return 1;
	}

	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d %s", CONTROL, REQ_CONNECT, argv[1]);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_CONNECT || result) {
		fprintf(stderr, "Could not connect to %s.\n", argv[1]);
		return 1;
	}

	return 0;
}

static int cmd_disconnect(int argc, char *argv[]) {
	if(argc != 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	if(!check_id(argv[2])) {
		fprintf(stderr, "Invalid name for node.\n");
		return 1;
	}

	if(!connect_tincd())
		return 1;

	sendline(fd, "%d %d %s", CONTROL, REQ_DISCONNECT, argv[1]);
	if(!recvline(fd, line, sizeof line) || sscanf(line, "%d %d %d", &code, &req, &result) != 3 || code != CONTROL || req != REQ_DISCONNECT || result) {
		fprintf(stderr, "Could not disconnect %s.\n", argv[1]);
		return 1;
	}

	return 0;
}

static int cmd_top(int argc, char *argv[]) {
#ifdef HAVE_CURSES
	if(!connect_tincd())
		return 1;

	top(fd);
	return 0;
#else
	fprintf(stderr, "This version of tincctl was compiled without support for the curses library.\n");
	return 1;
#endif
}

static int cmd_pcap(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	pcap(fd, stdout, argc > 1 ? atoi(argv[1]) : 0);
	return 0;
}

static int cmd_log(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	logcontrol(fd, stdout, argc > 1 ? atoi(argv[1]) : -1);
	return 0;
}

static int cmd_pid(int argc, char *argv[]) {
	if(!connect_tincd())
		return 1;

	printf("%d\n", pid);
	return 0;
}

static int rstrip(char *value) {
	int len = strlen(value);
	while(len && strchr("\t\r\n ", value[len - 1]))
		value[--len] = 0;
	return len;
}

static char *get_my_name() {
	FILE *f = fopen(tinc_conf, "r");
	if(!f) {
		fprintf(stderr, "Could not open %s: %s\n", tinc_conf, strerror(errno));
		return NULL;
	}

	char buf[4096];
	char *value;
	while(fgets(buf, sizeof buf, f)) {
		int len = strcspn(buf, "\t =");
		value = buf + len;
		value += strspn(value, "\t ");
		if(*value == '=') {
			value++;
			value += strspn(value, "\t ");
		}
		if(!rstrip(value))
			continue;
		buf[len] = 0;
		if(strcasecmp(buf, "Name"))
			continue;
		if(*value) {
			fclose(f);
			return strdup(value);
		}
	}

	fclose(f);
	fprintf(stderr, "Could not find Name in %s.\n", tinc_conf);
	return NULL;
}

static char *hostvariables[] = {
	"Address",
	"Port",
	"PublicKey",
	"Subnet",
	NULL,
};

static int cmd_config(int argc, char *argv[]) {
	if(argc < 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	int action = 0;
	if(!strcasecmp(argv[1], "add")) {
		argv++, argc--, action = 1;
	} else if(!strcasecmp(argv[1], "del")) {
		argv++, argc--, action = -1;
	} else if(!strcasecmp(argv[1], "replace") || !strcasecmp(argv[1], "set") || !strcasecmp(argv[1], "change")) {
		argv++, argc--, action = 0;
	}

	if(argc < 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	// Concatenate the rest of the command line
	strncpy(line, argv[1], sizeof line - 1);
	for(int i = 2; i < argc; i++) {
		strncat(line, " ", sizeof line - 1 - strlen(line));
		strncat(line, argv[i], sizeof line - 1 - strlen(line));
	}

	// Liberal parsing into node name, variable name and value.
	char *node = NULL;
	char *variable;
	char *value;
	int len;

        len = strcspn(line, "\t =");
        value = line + len;
        value += strspn(value, "\t ");
        if(*value == '=') {
                value++;
                value += strspn(value, "\t ");
        }
        line[len] = '\0';
	variable = strchr(line, '.');
	if(variable) {
		node = line;
		*variable++ = 0;
	} else {
		variable = line;
	}

	if(!*variable) {
		fprintf(stderr, "No variable given.\n");
		return 1;
	}

	if(action >= 0 && !*value) {
		fprintf(stderr, "No value for variable given.\n");
		return 1;
	}

	// Should this go into our own host config file?
	if(!node) {
		for(int i = 0; hostvariables[i]; i++) {
			if(!strcasecmp(hostvariables[i], variable)) {
				node = get_my_name();
				if(!node)
					return 1;
				break;
			}
		}
	}

	if(node && !check_id(node)) {
		fprintf(stderr, "Invalid name for node.\n");
		return 1;
	}

	// Open the right configuration file.
	char *filename;
	if(node)
		xasprintf(&filename, "%s/%s", hosts_dir, node);
	else
		filename = tinc_conf;

	FILE *f = fopen(filename, "r");
	if(!f) {
		if(action < 0 || errno != ENOENT) {
			fprintf(stderr, "Could not open configuration file %s: %s\n", filename, strerror(errno));
			return 1;
		}

		// If it doesn't exist, create it.
		f = fopen(filename, "a+");
		if(!f) {
			fprintf(stderr, "Could not create configuration file %s: %s\n", filename, strerror(errno));
			return 1;
		} else {
			fprintf(stderr, "Created configuration file %s.\n", filename);
		}
	}

	char *tmpfile;
	xasprintf(&tmpfile, "%s.config.tmp", filename);
	FILE *tf = fopen(tmpfile, "w");
	if(!tf) {
		fprintf(stderr, "Could not open temporary file %s: %s\n", tmpfile, strerror(errno));
		return 1;
	}

	// Copy the file, making modifications on the fly.
	char buf1[4096];
	char buf2[4096];
	bool set = false;
	bool removed = false;

	while(fgets(buf1, sizeof buf1, f)) {
		buf1[sizeof buf1 - 1] = 0;
		strcpy(buf2, buf1);

		// Parse line in a simple way
		char *bvalue;
		int len;

		len = strcspn(buf2, "\t =");
		bvalue = buf2 + len;
		bvalue += strspn(bvalue, "\t ");
		if(*bvalue == '=') {
			bvalue++;
			bvalue += strspn(bvalue, "\t ");
		}
		rstrip(bvalue);
		buf2[len] = '\0';

		// Did it match?
		if(!strcasecmp(buf2, variable)) {
			// Del
			if(action < 0) {
				if(!*value || !strcasecmp(bvalue, value)) {
					removed = true;
					continue;
				}
			// Set
			} else if(action == 0) {
				// Already set? Delete the rest...
				if(set)
					continue;
				// Otherwise, replace.
				if(fprintf(tf, "%s = %s\n", variable, value) < 0) {
					fprintf(stderr, "Error writing to temporary file %s: %s\n", tmpfile, strerror(errno));
					return 1;
				}
				set = true;
				continue;
			}
		}

		// Copy original line...
		if(fputs(buf1, tf) < 0) {
			fprintf(stderr, "Error writing to temporary file %s: %s\n", tmpfile, strerror(errno));
			return 1;
		}
	}

	// Make sure we read everything...
	if(ferror(f) || !feof(f)) {
		fprintf(stderr, "Error while reading from configuration file %s: %s\n", filename, strerror(errno));
		return 1;
	}

	if(fclose(f)) {
		fprintf(stderr, "Error closing configuration file %s: %s\n", filename, strerror(errno));
		return 1;
	}

	// Add new variable if necessary.
	if(action > 0 || (action == 0 && !set)) {
		if(fprintf(tf, "%s = %s\n", variable, value) < 0) {
			fprintf(stderr, "Error writing to temporary file %s: %s\n", tmpfile, strerror(errno));
			return 1;
		}
	}

	// Make sure we wrote everything...
	if(fclose(tf)) {
		fprintf(stderr, "Error closing temporary file %s: %s\n", tmpfile, strerror(errno));
		return 1;
	}

	// Could we find what we had to remove?
	if(action < 0 && !removed) {
		remove(tmpfile);
		fprintf(stderr, "No configuration variables deleted.\n");
		return *value;
	}

	// Replace the configuration file with the new one
#ifdef HAVE_MINGW
	if(remove(filename)) {
		fprintf(stderr, "Error replacing file %s: %s\n", filename, strerror(errno));
		return 1;
	}
#endif
	if(rename(tmpfile, filename)) {
		fprintf(stderr, "Error renaming temporary file %s to configuration file %s: %s\n", tmpfile, filename, strerror(errno));
		return 1;
	}

	// Silently try notifying a running tincd of changes.
	fclose(stderr);

	if(connect_tincd())
		sendline(fd, "%d %d", CONTROL, REQ_RELOAD);

	return 0;
}

bool check_id(const char *name) {
	for(int i = 0; i < strlen(name); i++) {
		if(!isalnum(name[i]) && name[i] != '_')
			return false;
	}

	return true;
}

static int cmd_init(int argc, char *argv[]) {
	if(!access(tinc_conf, F_OK)) {
		fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
		return 1;
	}

	if(argc < 2) {
		if(isatty(0) && isatty(1)) {
			char buf[1024];
			fprintf(stdout, "Enter the Name you want your tinc node to have: ");
			fflush(stdout);
			if(!fgets(buf, sizeof buf, stdin)) {
				fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
				return 1;
			}
			int len = rstrip(buf);
			if(!len) {
				fprintf(stderr, "No name given!\n");
				return 1;
			}
			name = strdup(buf);
		} else {
			fprintf(stderr, "No Name given!\n");
			return 1;
		}
	} else {
		name = strdup(argv[1]);
		if(!*name) {
			fprintf(stderr, "No Name given!\n");
			return 1;
		}
	}

	if(!check_id(name)) {
		fprintf(stderr, "Invalid Name! Only a-z, A-Z, 0-9 and _ are allowed characters.\n");
		return 1;
	}

	if(mkdir(CONFDIR, 0755) && errno != EEXIST) {
		fprintf(stderr, "Could not create directory %s: %s\n", CONFDIR, strerror(errno));
		return 1;
	}

	if(mkdir(confbase, 0755) && errno != EEXIST) {
		fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
		return 1;
	}

	char *hosts_dir = NULL;
	xasprintf(&hosts_dir, "%s/hosts", confbase);
	if(mkdir(hosts_dir, 0755) && errno != EEXIST) {
		fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
		return 1;
	}

	FILE *f = fopen(tinc_conf, "w");
	if(!f) {
		fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
		return 1;
	}

	fprintf(f, "Name = %s\n", name);
	fclose(f);

	fclose(stdin);
	if(!rsa_keygen(2048) || !ecdsa_keygen())
		return false;

	return true;

}

static int cmd_generate_keys(int argc, char *argv[]) {
	return !(rsa_keygen(argc > 1 ? atoi(argv[1]) : 2048) && ecdsa_keygen());
}

static int cmd_generate_rsa_keys(int argc, char *argv[]) {
	return !rsa_keygen(argc > 1 ? atoi(argv[1]) : 2048);
}

static int cmd_generate_ecdsa_keys(int argc, char *argv[]) {
	return !ecdsa_keygen();
}

static int cmd_help(int argc, char *argv[]) {
	usage(false);
	return 0;
}

static int cmd_version(int argc, char *argv[]) {
	version();
	return 0;
}

static const char *conffiles[] = {
	"tinc.conf",
	"tinc-up",
	"tinc-down",
	"subnet-up",
	"subnet-down",
	"host-up",
	"host-down",
	NULL,
};

static int cmd_edit(int argc, char *argv[]) {
	if(argc != 2) {
		fprintf(stderr, "Invalid number of arguments.\n");
		return 1;
	}

	char *filename = NULL;

	if(strncmp(argv[1], "hosts/", 6)) {
		for(int i = 0; conffiles[i]; i++) {
			if(!strcmp(argv[1], conffiles[i])) {
				xasprintf(&filename, "%s/%s", confbase, argv[1]);
				break;
			}
		}
	} else {
		argv[1] += 6;
	}

	if(!filename) {
		xasprintf(&filename, "%s/%s", hosts_dir, argv[1]);
		char *dash = strchr(argv[1], '-');
		if(dash) {
			*dash++ = 0;
			if((strcmp(dash, "up") && strcmp(dash, "down")) || !check_id(argv[1])) {
				fprintf(stderr, "Invalid configuration filename.\n");
				return 1;
			}
		}
	}

#ifndef HAVE_MINGW
	char *editor = getenv("VISUAL") ?: getenv("EDITOR") ?: "vi";
#else
	char *editor = "edit"
#endif

	char *command;
	xasprintf(&command, "\"%s\" \"%s\"", editor, filename);
	int result = system(command);
	if(result)
		return result;

	// Silently try notifying a running tincd of changes.
	fclose(stderr);

	if(connect_tincd())
		sendline(fd, "%d %d", CONTROL, REQ_RELOAD);

	return 0;
}

static const struct {
	const char *command;
	int (*function)(int argc, char *argv[]);
} commands[] = {
	{"start", cmd_start},
	{"stop", cmd_stop},
	{"restart", cmd_restart},
	{"reload", cmd_reload},
	{"dump", cmd_dump},
	{"purge", cmd_purge},
	{"debug", cmd_debug},
	{"retry", cmd_retry},
	{"connect", cmd_connect},
	{"disconnect", cmd_disconnect},
	{"top", cmd_top},
	{"pcap", cmd_pcap},
	{"log", cmd_log},
	{"pid", cmd_pid},
	{"config", cmd_config},
	{"init", cmd_init},
	{"generate-keys", cmd_generate_keys},
	{"generate-rsa-keys", cmd_generate_rsa_keys},
	{"generate-ecdsa-keys", cmd_generate_ecdsa_keys},
	{"help", cmd_help},
	{"version", cmd_version},
	{"edit", cmd_edit},
	{NULL, NULL},
};

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

	if(!parse_options(argc, argv))
		return 1;
	
	make_names();

	if(show_version) {
		version();
		return 0;
	}

	if(show_help) {
		usage(false);
		return 0;
	}

	if(optind >= argc) {
		fprintf(stderr, "No command given.\n");
		usage(true);
		return 1;
	}

	for(int i = 0; commands[i].command; i++) {
		if(!strcasecmp(argv[optind], commands[i].command))
			return commands[i].function(argc - optind, argv + optind);
	}

	fprintf(stderr, "Unknown command `%s'.\n", argv[optind]);
	usage(true);
	return 1;
}