/* 
   Copyright (C) 2012 by Peter Lieven <pl@kamp.de>
   Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
   
   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, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <poll.h>
#include <popt.h>
#include "iscsi.h"
#include "scsi-lowlevel.h"

const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:iscsi-readcapacity16";

void print_usage(void)
{
	fprintf(stderr, "Usage: iscsi-readcapacity16 [-?] [-?|--help] [--usage] [-i|--initiator-name=iqn-name] <iscsi-url>\n");
}

void print_help(void)
{
	fprintf(stderr, "Usage: iscsi_readcapacity16 [OPTION...] <iscsi-url>\n");
	fprintf(stderr, "  -i, --initiator-name=iqn-name     Initiatorname to use\n");
	fprintf(stderr, "  -d, --debug=integer               debug level (0=disabled)\n");
	fprintf(stderr, "\n");
	fprintf(stderr, "Help options:\n");
	fprintf(stderr, "  -?, --help                        Show this help message\n");
	fprintf(stderr, "      --usage                       Display brief usage message\n");
	fprintf(stderr, "\n");
	fprintf(stderr, "iSCSI URL format : %s\n", ISCSI_URL_SYNTAX);
	fprintf(stderr, "\n");
	fprintf(stderr, "<host> is either of:\n");
	fprintf(stderr, "  \"hostname\"       iscsi.example\n");
	fprintf(stderr, "  \"ipv4-address\"   10.1.1.27\n");
	fprintf(stderr, "  \"ipv6-address\"   [fce0::1]\n");
}

int main(int argc, const char *argv[])
{
	poptContext pc;
	struct iscsi_context *iscsi;
	const char **extra_argv;
	int extra_argc = 0;
	const char *url = NULL;
	struct iscsi_url *iscsi_url = NULL;
	int show_help = 0, show_usage = 0, debug = 0;
	int res;

	struct poptOption popt_options[] = {
		{ "help", '?', POPT_ARG_NONE, &show_help, 0, "Show this help message", NULL },
		{ "usage", 0, POPT_ARG_NONE, &show_usage, 0, "Display brief usage message", NULL },
		{ "initiator-name", 'i', POPT_ARG_STRING, &initiator, 0, "Initiatorname to use", "iqn-name" },
		{ "debug", 'd', POPT_ARG_INT, &debug, 0, "Debugging level", "integer" },
		POPT_TABLEEND
	};

	pc = poptGetContext(argv[0], argc, argv, popt_options, POPT_CONTEXT_POSIXMEHARDER);
	if ((res = poptGetNextOpt(pc)) < -1) {
		fprintf(stderr, "Failed to parse option : %s %s\n",
			poptBadOption(pc, 0), poptStrerror(res));
		exit(10);
	}
	extra_argv = poptGetArgs(pc);
	if (extra_argv) {
		url = *extra_argv;
		extra_argv++;
		while (extra_argv[extra_argc]) {
			extra_argc++;
		}
	}

	if (show_help != 0) {
		print_help();
		exit(0);
	}

	if (show_usage != 0) {
		print_usage();
		exit(0);
	}

	poptFreeContext(pc);

	iscsi = iscsi_create_context(initiator);
	if (iscsi == NULL) {
		fprintf(stderr, "Failed to create context\n");
		exit(10);
	}

    if (debug > 0) {
        iscsi_set_debug(iscsi, debug);
    }

	if (url == NULL) {
		fprintf(stderr, "You must specify the URL\n");
		print_usage();
		exit(10);
	}
	iscsi_url = iscsi_parse_full_url(iscsi, url);
	if (iscsi_url == NULL) {
		fprintf(stderr, "Failed to parse URL: %s\n", 
			iscsi_get_error(iscsi));
		exit(10);
	}

	iscsi_set_targetname(iscsi, iscsi_url->target);
	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
	iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);

	if (iscsi_url->user != NULL) {
		if (iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user, iscsi_url->passwd) != 0) {
			fprintf(stderr, "Failed to set initiator username and password\n");
			exit(10);
		}
	}

	if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
		fprintf(stderr, "Login Failed. %s\n", iscsi_get_error(iscsi));
		iscsi_destroy_url(iscsi_url);
		iscsi_destroy_context(iscsi);
		exit(10);
	}

	struct scsi_task *task;
	struct scsi_readcapacity16 *rc16;

	task = iscsi_readcapacity16_sync(iscsi, iscsi_url->lun);
	if (task == NULL || task->status != SCSI_STATUS_GOOD) {
		fprintf(stderr,"failed to send readcapacity command\n");
		iscsi_destroy_url(iscsi_url);
		iscsi_destroy_context(iscsi);
		exit(10);
	}

	rc16 = scsi_datain_unmarshall(task);
	if (rc16 == NULL) {
		fprintf(stderr,"failed to unmarshall readcapacity16 data\n");
		scsi_free_scsi_task(task);
		iscsi_destroy_url(iscsi_url);
		iscsi_destroy_context(iscsi);
		exit(10);
	}
      
    fprintf(stdout,"%lu",rc16->block_length*(rc16->returned_lba + 1));

	iscsi_destroy_url(iscsi_url);

	iscsi_logout_sync(iscsi);
	iscsi_destroy_context(iscsi);
	return 0;
}