/* This file is part of Netsukuku
 *
 * This source code 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 source code 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.
 * Please refer to the GNU Public License for more details.
 *
 * You should have received a copy of the GNU Public License along with
 * this source code; if not, write to:
 * Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <netinet/in.h>

#include "includes.h"

#include "ntkresolv.h"
#include "andns_net.h"
#include "snsd_cache.h"
#include "crypto.h"
#include "common.h"

static ntkresolv_opts globopts;
static struct timeval time_start, time_stop;
uint8_t mode_compute_hash = 0;
uint8_t mode_parsable_output = 0;

void
version(void)
{
	say("ntk-resolv version %s (Netsukuku tools)\n\n"
		"Copyright (C) 2006.\n"
		"This is free software.  You may redistribute copies of it under the terms of\n"
		"the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.\n"
		"There is NO WARRANTY, to the extent permitted by law.\n\n"
		"Report bugs and ideas to <%s>.\n", VERSION, NTK_RESOLV_MAIL_BUGS);
	ntkresolv_safe_exit(1);
}


void
usage(void)
{
	say("Usage:\n"
		"\tntk-resolv [OPTIONS] host\n"
		"\tntk-resolv -H host\n\n"
		" -v --version          print version, then exit.\n"
		" -n --nameserver=ns    use nameserver `ns' instead of localhost.\n"
		" -P --port=port        nameserver port, default 53.\n"
		" -t --query-type=qt    query type (`-t help' shows more info).\n"
		" -r --realm=realm      realm to scan (`-r help' shows more info).\n"
		" -s --service=service  SNSD service (`-s help' shows more info).\n"
		" -p --protocolo=proto  SNSD protocol (`-p help' shows more info).\n"
		" -S --silent           ntk-resolv will be not loquacious.\n"
		" -b --block-recursion  set recursion OFF.\n"
		" -m --md5-hash         hostname specified is hash-ed.\n"
		" -H --compute-hash     print the hash'ed hostname.\n"
		" -l --parsable-output  print answers in a synthetic way.\n"
		" -h --help             display this help, then exit.\n\n"
		"Report bugs and ideas to <%s>.\n", NTK_RESOLV_MAIL_BUGS);
	ntkresolv_safe_exit(1);
}

void
qt_usage(char *arg)
{
	if (arg)
		say("Bad Query Type %s\n\n", arg);
	else
		say("ntk-resolv Query Type Help.\n\n");
	say("Valid query types are:\n"
		" * snsd\t\thost:port -> ip\n"
		"   ptr\t\tip -> host\n"
		"   global\thostname -> all services ip\n"
		"   mx\t\thostname MX -> ip\n\n"
		"(you can also use univoque abbreviation)\n"
		"Note: mx query is equivalent to --query-type="
		"snsd AND --service=25\n\n");
	ntkresolv_safe_exit(1);
}

void
realm_usage(char *arg)
{
	if (arg)
		say("Bad Realm %s\n\n", arg);
	else
		say("ntk-resolv Realm Help.\n\n");
	say("Valid realms are:\n"
		" * ntk\tnetsukuku realm\n"
		"   inet\tinternet realm\n\n"
		"(you can also use univoque abbreviation)\n\n");
	ntkresolv_safe_exit(1);
}

void
proto_usage(char *arg)
{
	if (arg)
		say("Bad Protocol %s\n\n", arg);
	else
		say("ntk-resolv Protocol Help.\n\n");
	say("Valid protocols are:\n"
		" * tcp\n"
		"   udp\n"
		"(you can also use univoque abbreviation)\n"
		"Note: you can also specify the protocol with option `-s'.\n"
		"To know more, type:\n" "\tntk-resolv -s help\n\n");
	ntkresolv_safe_exit(1);
}

void
service_and_proto_usage(char *arg)
{
	if (arg)
		say("Bad service/proto %s\n\n"
			"Use `ntk-resolv -s help` for more info on"
			" service and proto.\n", arg);
	else
		say("ntk-resolv Service and Proto Help.\n\n"
			"The form to specify a service and a protocol are:\n"
			"  ntk-resolv -s service/proto\n"
			"  ntk-resolv -s service -p proto\n\n"
			"Valid protocols are:\n"
			" * tcp\n"
			"   udp\n\n"
			"Valid services are expressed in /etc/services.\n"
			"You can use numeric form too.\n\n"
			"As example, the next commands are equivalent and\n"
			"will return the IP of the hostname that offers\n"
			"webpages for the hostname \"some_hostname\":\n\n"
			"  ntk-resolv -s http -p tcp some_hostname\n"
			"  ntk-resolv -s http/tcp    some_hostname\n"
			"  ntk-resolv -s 80/tcp      some_hostname\n"
			"  ntk-resolv -s 80          some_hostname\n\n");
	ntkresolv_safe_exit(1);
}


double
diff_time(struct timeval a, struct timeval b)
{
	double res;
	res = (double) (b.tv_sec - a.tv_sec);
	if (res < 0.9 || b.tv_usec >= a.tv_usec)
		res += (b.tv_usec - a.tv_usec) / TIME_SCALE;
	else {
		res -= 1.0;
		res += (TIME_SCALE + b.tv_usec - a.tv_usec) / TIME_SCALE;
	}
	return res;
}


void
opts_init(void)
{
	memset(&GOP, 0, NTKRESOLV_OPTS_SZ);
	strcpy(GOP.nsserver, LOCALHOST);
	GOP.port = NTKRESOLV_PORT;
	GQT = create_andns_pkt();
	GQT->nk = REALM_NTK;
	GQT->p = SNSD_PROTO_DEFAULT;
	GQT->service = SNSD_SERVICE_DEFAULT;
	GQT->r = 1;
	xsrand();
}

void
opts_set_silent(void)
{
	GOP.silent = 1;
}

void
opts_set_port(char *arg)
{
	int res;
	uint16_t port;

	res = atoi(arg);
	port = (uint16_t) res;

	if (port != res) {
		say("Bad port %s.", arg);
		ntkresolv_safe_exit(1);
	}
	GOP.port = port;
}

void
opts_set_ns(char *arg)
{
	int slen;

	slen = strlen(arg);
	if (slen >= MAX_HOSTNAME_LEN) {
		say("Server hostname too long.");
		ntkresolv_safe_exit(1);
	}
	strcpy(GOP.nsserver, arg);
	GOP.nsserver[slen] = 0;
}

void
opts_set_qt(char *arg)
{
	int res;

	if (!strcmp(arg, HELP_STR))
		qt_usage(NULL);
	res = QTFROMPREF(arg);
	if (res == -1)
		qt_usage(arg);
	if (res == QTYPE_MX) {
		GQT->qtype = QTYPE_A;
		GQT->service = 25;
		GQT->p = SNSD_PROTO_TCP;
	} else
		GQT->qtype = res;
}

void
opts_set_realm(char *arg)
{
	uint8_t res;

	if (!strcmp(arg, HELP_STR))
		realm_usage(NULL);
	res = REALMFROMPREF(arg);
	if (!res)
		realm_usage(arg);
	GQT->nk = res;
}

void
opts_set_service_and_proto(char *arg)
{
	int ret;

	if (!strcmp(arg, HELP_STR))
		service_and_proto_usage(NULL);
	ret = str_to_snsd_service(arg, (int *) &GQT->service, &GQT->p);
/*	if(ret == -1)
		say("Bad service %s.",arg);
	else if(ret == -2)
		proto_usage(arg);*/
	if (ret < 0)
		service_and_proto_usage(arg);
	GQT->p -= 1;
}

void
opts_set_proto(char *arg)
{
	int ret;

	if (!strcmp(arg, HELP_STR))
		proto_usage(NULL);
	ret = PROTOFROMPREF(arg);
	if (ret < 0)
		proto_usage(arg);
	GQT->p = ret;
}

/* This is a complex set of function. */
void
opts_set_recursion(void)
{
	GQT->r = 0;
}

void
opts_set_hash(void)
{
	GOP.hash = 1;
}

void
opts_set_compute_hash(void)
{
	mode_compute_hash = 1;
}

void
opts_set_parsable_output(void)
{
	mode_parsable_output = 1;
	AMISILENT = 1;
}

void
opts_set_question(char *arg)
{
	struct in_addr ia;
	struct in6_addr i6a;
	int res;

	strcpy(GOP.obj, arg);
	res = strlen(arg);

	switch (GQT->qtype) {
	case QTYPE_A:
		if (GQT->nk == REALM_NTK) {
			G_ALIGN(ANDNS_HASH_H);
			if (GOP.hash) {
				if (res != 2 * ANDNS_HASH_H) {
					say("Malformed Hostname hash `%s'.\n", arg);
					ntkresolv_safe_exit(1);
				}
				NTK_RESOLV_STR_HASH(arg, GQT->qstdata);
			} else
				hash_md5((unsigned char *) arg, res,
						 (unsigned char *) GQT->qstdata);
		} else {
			if (res > 255) {
				say("Hostname %s is too long for DNS standard.", arg);
				ntkresolv_safe_exit(1);
			}
			G_ALIGN(res);
			strcpy(GQT->qstdata, arg);
		}
		return;
	case QTYPE_PTR:
		res = inet_pton(AF_INET, arg, &ia);
		if (res) {
			G_ALIGN(ANDNS_HASH_H);
			memcpy(GQT->qstdata, &ia.s_addr, 4);
			return;
		}
		res = inet_pton(AF_INET6, arg, &i6a);
		if (!res) {
			say("Bad address `%s'\n", arg);
			ntkresolv_safe_exit(1);
		}
		G_ALIGN(16);
		memcpy(GQT->qstdata, &i6a.__in6_u, 16);
		GQT->ipv = ANDNS_IPV6;
		return;
	case QTYPE_G:
		if (GQT->nk != REALM_NTK) {
			say("Global query type is valid only for the Ntk realm.");
			ntkresolv_safe_exit(1);
		}
		G_ALIGN(ANDNS_HASH_H);
		if (GOP.hash)
			NTK_RESOLV_STR_HASH(arg, GQT->qstdata);
		else
			hash_md5((unsigned char *) arg, res,
					 (unsigned char *) GQT->qstdata);
		return;
	default:
		say("Unknow Query Type.\n");
		return;
	}
}

void
opts_finish(char *arg)
{
	int r;

	r = strlen(arg);
	if (r > NTKRESOLV_MAX_OBJ_LEN) {
		say("Object requested is too long: %s", arg);
		ntkresolv_safe_exit(1);
	}

	if (mode_compute_hash) {	/* Do command here and exit */
		G_ALIGN(ANDNS_HASH_H);
		hash_md5((unsigned char *) arg, r, (unsigned char *) GQT->qstdata);
		NTK_RESOLV_HASH_STR(GQT->qstdata, GOP.obj);
		say("%s\n", GOP.obj);
		ntkresolv_safe_exit(0);
	}
	if (GOP.hash && GQT->qtype == AT_PTR) {
		say("Option `-m' is not usable with inverse queries.\n");
		ntkresolv_safe_exit(1);
	}
	r = rand();
	GQT->id = r >> 16;
	opts_set_question(arg);
}

void
print_headers()
{
	andns_pkt *ap = GQT;
	say("\n - Headers Section:\n"
		"\tid ~ %6d\tqr  ~ %4d\tqtype ~ %7s\n"
		"\tan ~ %6d\tipv ~ %s\trealm ~ %7s\n"
		"\tsv ~ %6s\tprt ~ %4s\trCode ~ %s\n"
		"\trc ~ %6d\n",
		ap->id, ap->qr, QTYPE_STR(ap),
		ap->ancount, IPV_STR(ap), NK_STR(ap),
		SERVICE_STR(ap), PROTO_STR(ap), RCODE_STR(ap), ap->r);
}

void
print_question()
{
	say("\n - Question Section:\n" "\tObj ~ %s\n", GOP.obj);
}

void
ip_bin_to_str(void *data, char *dst)
{
	int family;
	struct in_addr ia;
	struct in6_addr i6a;
	const void *via;
	const char *crow;

	family = GQT->ipv == ANDNS_IPV4 ? AF_INET : AF_INET6;
	switch (family) {
	case AF_INET:
		memcpy(&(ia.s_addr), data, 4);
		via = (void *) (&ia);
		break;
	case AF_INET6:
		memcpy(&(i6a.__in6_u), data, 16);
		via = (void *) (&i6a);
		break;
	default:
		strcpy(dst, "Unprintable Object");
		return;
	}
	crow = inet_ntop(family, via, dst, NTKRESOLV_MAX_OBJ_LEN);
	if (!crow)
		strcpy(dst, "Unprintable Object");
}

void
answer_data_to_str(andns_pkt_data * apd, char *dst)
{
	if (GQT->qtype == AT_PTR)
		strcpy(dst, apd->rdata);
	else if (GQT->qtype == AT_G || GQT->qtype == AT_A) {
		if (apd->m & APD_IP)
			ip_bin_to_str(apd->rdata, dst);
		else
			NTK_RESOLV_HASH_STR(apd->rdata, dst);
	} else
		strcpy(dst, "Unprintable Object");
}

void
print_answers()
{
	int i = 0;
	int ancount = GQT->ancount;
	andns_pkt_data *apd;

	if (!ancount)
		return;

	say("\n - Answers Section:\n");

	apd = GQT->pkt_answ;
	while (apd) {
		i++;
		if (i > ancount)
			say("Answer not declared in Headers Packet.\n");
		answer_data_to_str(apd, GOP.obj);
		say("\t ~ %s", GOP.obj);
		if (apd->m & APD_MAIN_IP)
			say(" *");
		else if (GQT->qtype != AT_PTR && !(apd->m & APD_IP) && GQT->r)
			say("\t + Recursion Failed");
		say("\n");
		if (GQT->qtype == AT_A || GQT->qtype == AT_G)
			say("\t\tPrio ~ %d  Weigth ~ %d\n", apd->prio, apd->wg);
		if (GQT->qtype == AT_G)
			say("\t\tService ~ %d  Proto ~ %s\n",
				apd->service, apd->m & APD_UDP ? "udp" : "tcp");
		say("\n");
		apd = apd->next;
	}
}

void
print_parsable_answers(void)
{
	int i = 0;
	int ancount = GQT->ancount;
	andns_pkt_data *apd;

	if (!ancount)
		return;

	apd = GQT->pkt_answ;
	while (apd) {
		i++;
		if (i > ancount)
			say("Answer not declared in Headers Packet.\n");
		answer_data_to_str(apd, GOP.obj);
		if (GQT->qtype == AT_PTR || (GQT->qtype == AT_A && !GQT->service))
			say("%s %s\n", NTK_RESOLV_SYMBOL(apd), GOP.obj);
		else if (GQT->qtype == AT_A)
			say("%s %s %d %d\n", NTK_RESOLV_SYMBOL(apd),
				GOP.obj, apd->prio, apd->wg);
		else
			say("%s %s %d %s %d %d\n", NTK_RESOLV_SYMBOL(apd),
				GOP.obj, apd->service,
				apd->m & APD_UDP ? "udp" : "tcp", apd->prio, apd->wg);
		apd = apd->next;
	}
}

void
print_results(void)
{
	if (!AMISILENT) {
		print_headers();
		print_question();
	}
	if (mode_parsable_output)
		print_parsable_answers();
	else
		print_answers();
}

void
do_command(void)
{
	char buf[ANDNS_MAX_SZ];
	char answer[ANDNS_MAX_PK_LEN];
	int res;

	memset(buf, 0, ANDNS_MAX_SZ);
	GOP.id = GQT->id;
	res = a_p(GQT, buf);
	if (res == -1) {
		say("Error building question.\n");
		ntkresolv_exit(1);
	}
	res = hn_send_recv_close(GOP.nsserver, GOP.port,
							 SOCK_DGRAM, buf, res, answer,
							 ANDNS_MAX_PK_LEN, 0, NTK_RESOLV_TIMEOUT);
	if (res == -1) {
		say("Communication failed with %s.\n", GOP.nsserver);
		ntkresolv_exit(1);
	}
	if (res == -2) {
		say("Unable to send() to %s.\n", GOP.nsserver);
		ntkresolv_exit(1);
	}
	if (res == -3) {
		say("Unable to recv() from %s.\n", GOP.nsserver);
		ntkresolv_exit(1);
	}
	res = a_u(answer, res, &GQT);
	if (res <= 0) {
		say("Error interpreting server answer.\n");
		ntkresolv_exit(1);
	}
	if (GQT->id != GOP.id)
		say("Warning: ID query (%d) is mismatching ID answer (%d)!\n",
			GOP.id, GQT->id);

	print_results();
	destroy_andns_pkt(GQT);
}

void
ntkresolv_exit(int i)
{
	exit(i);
}

void
ntkresolv_safe_exit(int i)
{
	destroy_andns_pkt(GQT);
	ntkresolv_exit(i);
}

int
main(int argc, char **argv)
{
	int c;
	extern int optind, opterr, optopt;
	extern char *optarg;

	log_init("", 0, 1);
	gettimeofday(&time_start, NULL);

	opts_init();
	struct option longopts[] = {
		{"version", 0, 0, 'v'},
		{"nameserver", 1, 0, 'n'},
		{"port", 1, 0, 'P'},
		{"query-type", 1, 0, 't'},
		{"realm", 1, 0, 'r'},
		{"service", 1, 0, 's'},
		{"proto", 1, 0, 'p'},
		{"silent", 0, 0, 'S'},
		{"block-recursion", 0, 0, 'b'},
		{"md5-hash", 0, 0, 'm'},
		{"compute-hash", 0, 0, 'H'},
		{"parsable-output", 0, 0, 'l'},
		{"help", 0, 0, 'h'},
		{0, 0, 0, 0}
	};

	while (1) {
		int oindex = 0;
		c = getopt_long(argc, argv,
						"vn:P:t:r:s:p:ShbmHl", longopts, &oindex);
		if (c == -1)
			break;
		switch (c) {
		case 'v':
			version();
		case 'n':
			opts_set_ns(optarg);
			break;
		case 'P':
			opts_set_port(optarg);
			break;
		case 't':
			opts_set_qt(optarg);
			break;
		case 'r':
			opts_set_realm(optarg);
			break;
		case 's':
			opts_set_service_and_proto(optarg);
			break;
		case 'p':
			opts_set_proto(optarg);
			break;
		case 'h':
			usage();
		case 'S':
			opts_set_silent();
			break;
		case 'b':
			opts_set_recursion();
			break;
		case 'm':
			opts_set_hash();
			break;
		case 'H':
			opts_set_compute_hash();
			break;
		case 'l':
			opts_set_parsable_output();
			break;
		default:
			usage();
		}
	}
	if (optind == argc)
		usage();
	opts_finish(argv[optind]);
	do_command();
	time_report;
	bye;
	return 0;
}