/* 
   Copyright (C) 2015 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/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_POLL_H
#include <poll.h>
#else
#include "win32_compat.h"
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/time.h>

#include "iscsi.h"
#include "iscsi-private.h"
#include "scsi-lowlevel.h"

const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:prog-header-digest";

struct client_state {
       int finished;
       int status;
       int lun;
};

#define TIMER_START(x) gettimeofday(&x, NULL)
#define TIMER_ELAPSED(x, y) do { \
		struct timeval t; \
		int wrap = 0; \
		gettimeofday(&t, NULL); \
		if (t.tv_usec < x.tv_usec) wrap = 1; \
			y.tv_sec = t.tv_sec - x.tv_sec - wrap; \
			y.tv_usec = wrap * 10000000 + t.tv_usec - x.tv_usec; \
	} while(0)

void event_loop(struct iscsi_context *iscsi, struct client_state *state,
		int timeout)
{
	struct pollfd pfd;
	struct timeval start_time, elapsed_time;

	TIMER_START(start_time);
	while (state->finished == 0) {
		pfd.fd = iscsi_get_fd(iscsi);
		pfd.events = iscsi_which_events(iscsi);

		if (poll(&pfd, 1, 1000) < 0) {
			fprintf(stderr, "Poll failed");
			exit(10);
		}
		if (iscsi_service(iscsi, pfd.revents) < 0) {
			fprintf(stderr, "iscsi_service failed with : %s\n",
				iscsi_get_error(iscsi));
			exit(10);
		}
		TIMER_ELAPSED(start_time, elapsed_time);
		if (timeout && elapsed_time.tv_sec > timeout) {
			break;
		}
	}
}

void tur_cb(struct iscsi_context *iscsi, int status,
	    void *command_data, void *private_data)
{
	struct client_state *state = (struct client_state *)private_data;

	if (status != 0) {
		fprintf(stderr, "TestUnitReady failed\n");
		state->status = status;
	}

	state->finished = 1;
}

void print_usage(void)
{
	fprintf(stderr, "Usage: prog_header_digest [-?|--help] [--usage] "
		"[-i|--initiator-name=iqn-name]\n"
		"\t\t<iscsi-portal-url>\n");
	fprintf(stderr, "\n");
	fprintf(stderr, "This command is used to test that if the target "
		"disconnects libiscsi will automatically reconnect and "
		"re-issue all queued tasks.\n");
}

void print_help(void)
{
	fprintf(stderr, "Usage: prog_header_digest [OPTION...] <iscsi-url>\n");
	fprintf(stderr, "  -i, --initiator-name=iqn-name     "
		"Initiatorname to use\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 Portal URL format : %s\n",
		ISCSI_PORTAL_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, char *argv[])
{
	struct iscsi_context *iscsi;
	struct iscsi_url *iscsi_url = NULL;
	struct client_state state;
	char *url = NULL;
	int c;
	static int show_help = 0, show_usage = 0, debug = 0;

	static struct option long_options[] = {
		{"help",           no_argument,          NULL,        'h'},
		{"usage",          no_argument,          NULL,        'u'},
		{"debug",          no_argument,          NULL,        'd'},
		{"initiator-name", required_argument,    NULL,        'i'},
		{0, 0, 0, 0}
	};
	int option_index;

	while ((c = getopt_long(argc, argv, "h?uUdi:s", long_options,
			&option_index)) != -1) {
		switch (c) {
		case 'h':
		case '?':
			show_help = 1;
			break;
		case 'u':
			show_usage = 1;
			break;
		case 'd':
			debug = 1;
			break;
		case 'i':
			initiator = optarg;
			break;
		default:
			fprintf(stderr, "Unrecognized option '%c'\n\n", c);
			print_help();
			exit(0);
		}
	}

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

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

	if (optind != argc -1) {
		print_usage();
		exit(0);
	}

	memset(&state, 0, sizeof(state));

	if (argv[optind] != NULL) {
		url = strdup(argv[optind]);
	}
	if (url == NULL) {
		fprintf(stderr, "You must specify iscsi target portal.\n");
		print_usage();
		exit(10);
	}

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

	if (debug > 0) {
		iscsi_set_log_level(iscsi, debug);
		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
	}

	iscsi_url = iscsi_parse_full_url(iscsi, url);

        free(url);

	if (iscsi_url == NULL) {
		fprintf(stderr, "Failed to parse URL: %s\n", 
			iscsi_get_error(iscsi));
		exit(10);
	}

	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
	printf("Enable Header Digest\n");
        iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_CRC32C);

	printf("Disable iscsi reconnect on session failure\n");
	iscsi_set_noautoreconnect(iscsi, 1);
        
	state.lun = iscsi_url->lun;
	if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun)
	    != 0) {
		fprintf(stderr, "iscsi_connect failed. %s\n",
			iscsi_get_error(iscsi));
		exit(10);
	}

	printf("Verify that the connection works\n");
	if (iscsi_testunitready_task(iscsi, state.lun,
				     tur_cb, &state) == NULL) {
		fprintf(stderr, "testunitready failed\n");
		exit(10);
	}
	event_loop(iscsi, &state, 3);

	iscsi_destroy_url(iscsi_url);
	iscsi_disconnect(iscsi);
	iscsi_destroy_context(iscsi);

	if (state.status != 0) {
		exit(10);
	}
	return 0;
}