iscsi-device.c

ISCSI user client software.Client would be used to access the IPSAN server.

/*
 * iSCSI driver for Linux
 * Copyright (C) 2001 Cisco Systems, Inc.
 * maintained by [e-mail]
 *
 * 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.
 *
 * See the file COPYING included with this distribution for more details.
 *
 * $Id: iscsi-device.c,v 1.4 2004/07/07 09:45:10 surekhap Exp $
 *
 * Determine if a Linux SCSI device is an iSCSI device.
 *
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#include <string.h>
#include <inttypes.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>

/* <asm/types.h> does not export u8 definition outside kernel
 * forcing us to define it here.
 */
typedef unsigned char u8;

#include <scsi/scsi.h>

#define ISCSI_SYS_DIR	"/sys/class/scsi_host/"

/* if the device name on the command line exists and is an iSCSI device,
 * then output a description of the iSCSI target to stdout, and exit 0.
 * if the device name might be an iSCSI device, exit 1.
 * if the device name definately is not an iSCSI device, exit 2.
 */

int
main(int argc, char *argv[])
{
	FILE *fp;
	char devname[PATH_MAX + 1];
	int host, channel, id, lun;
	char *device = argv[1];
	char name[20];
	int fd;
	u_long arg[2];

	if (argc > 2) {
		fprintf(stderr, "iscsi-device: error, too many arguments,"
			" only 1 device name is allowed.\n");
	}
	if (argc != 2) {
		fprintf(stderr, "\nUsage: iscsi-device devicename\n\n");
		exit(2);
	}

	/* get the (host,channel,id,lun) quadruple for this device, if possible
	 */
	if ((fd = open(device, O_RDONLY)) >= 0) {
		memset(&arg, 0, sizeof(arg));
		/* try to get the host, channel, id, lun quadruple */
		if (ioctl(fd, SCSI_IOCTL_GET_IDLUN, &arg) == 0) {
			id = arg[0] & 0xff;
			lun = (arg[0] >> 8) & 0xff;
			channel = (arg[0] >> 16) & 0xff;
			host = (arg[0] >> 24) & 0xff;
		} else {
			fprintf(stderr,
				"iscsi-device: ioctl SCSI_IOCTL_GET_IDLUN "
				"%s failed, %s\n", device, strerror(errno));
			close(fd);
			exit(1);
		}
	} else {
		fprintf(stderr, "iscsi-device: couldn't open %s, %s\n", device,
			strerror(errno));
		exit(1);
	}
	close(fd);

	sprintf(devname, "%s/host%d/proc_name", ISCSI_SYS_DIR, host);

	if ((fp = fopen(devname, "r"))) {
		fscanf(fp, "%s", name);
		fclose(fp);
		if (!strcmp(name, "iscsi-sfnet")) {
			printf("%s is an iSCSI device \n", device);
			exit(0);
		}
	}
	/* didn't find a match */
	fprintf(stderr, "iscsi-device: %s is not an iSCSI device\n", device);
	exit(2);
}