drivers/target/target_core_fabric_lib.c - linux/kernel/git/viro/vfs - Git at Google

 /*******************************************************************************
  * Filename:  target_core_fabric_lib.c
  *
  * This file contains generic high level protocol identifier and PR
  * handlers for TCM fabric modules
  *
  * (c) Copyright 2010-2013 Datera, Inc.
  *
  * Nicholas A. Bellinger <nab@linux-iscsi.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
  ******************************************************************************/

 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/spinlock.h>
 #include <linux/export.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>

 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>
 #include <target/target_core_configfs.h>

 #include "target_core_internal.h"
 #include "target_core_pr.h"

 /*
  * Handlers for Serial Attached SCSI (SAS)
  */
 u8 sas_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 {
 	/*
 	 * Return a SAS Serial SCSI Protocol identifier for loopback operations
 	 * This is defined in  section 7.5.1 Table 362 in spc4r17
 	 */
 	return 0x6;
 }
 EXPORT_SYMBOL(sas_get_fabric_proto_ident);

 u32 sas_get_pr_transport_id(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code,
 	unsigned char *buf)
 {
 	unsigned char *ptr;
 	int ret;

 	/*
 	 * Set PROTOCOL IDENTIFIER to 6h for SAS
 	 */
 	buf[0] = 0x06;
 	/*
 	 * From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
 	 * over SAS Serial SCSI Protocol
 	 */
 	ptr = &se_nacl->initiatorname[4]; /* Skip over 'naa. prefix */

 	ret = hex2bin(&buf[4], ptr, 8);
 	if (ret < 0)
 		pr_debug("sas transport_id: invalid hex string\n");

 	/*
 	 * The SAS Transport ID is a hardcoded 24-byte length
 	 */
 	return 24;
 }
 EXPORT_SYMBOL(sas_get_pr_transport_id);

 u32 sas_get_pr_transport_id_len(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code)
 {
 	*format_code = 0;
 	/*
 	 * From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
 	 * over SAS Serial SCSI Protocol
 	 *
 	 * The SAS Transport ID is a hardcoded 24-byte length
 	 */
 	return 24;
 }
 EXPORT_SYMBOL(sas_get_pr_transport_id_len);

 /*
  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
  */
 char *sas_parse_pr_out_transport_id(
 	struct se_portal_group *se_tpg,
 	const char *buf,
 	u32 *out_tid_len,
 	char **port_nexus_ptr)
 {
 	/*
 	 * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
 	 * for initiator ports using SCSI over SAS Serial SCSI Protocol
 	 *
 	 * The TransportID for a SAS Initiator Port is of fixed size of
 	 * 24 bytes, and SAS does not contain a I_T nexus identifier,
 	 * so we return the **port_nexus_ptr set to NULL.
 	 */
 	*port_nexus_ptr = NULL;
 	*out_tid_len = 24;

 	return (char *)&buf[4];
 }
 EXPORT_SYMBOL(sas_parse_pr_out_transport_id);

 /*
  * Handlers for Fibre Channel Protocol (FCP)
  */
 u8 fc_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 {
 	return 0x0;	/* 0 = fcp-2 per SPC4 section 7.5.1 */
 }
 EXPORT_SYMBOL(fc_get_fabric_proto_ident);

 u32 fc_get_pr_transport_id_len(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code)
 {
 	*format_code = 0;
 	/*
 	 * The FC Transport ID is a hardcoded 24-byte length
 	 */
 	return 24;
 }
 EXPORT_SYMBOL(fc_get_pr_transport_id_len);

 u32 fc_get_pr_transport_id(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code,
 	unsigned char *buf)
 {
 	unsigned char *ptr;
 	int i, ret;
 	u32 off = 8;

 	/*
 	 * PROTOCOL IDENTIFIER is 0h for FCP-2
 	 *
 	 * From spc4r17, 7.5.4.2 TransportID for initiator ports using
 	 * SCSI over Fibre Channel
 	 *
 	 * We convert the ASCII formatted N Port name into a binary
 	 * encoded TransportID.
 	 */
 	ptr = &se_nacl->initiatorname[0];

 	for (i = 0; i < 24; ) {
 		if (!strncmp(&ptr[i], ":", 1)) {
 			i++;
 			continue;
 		}
 		ret = hex2bin(&buf[off++], &ptr[i], 1);
 		if (ret < 0)
 			pr_debug("fc transport_id: invalid hex string\n");
 		i += 2;
 	}
 	/*
 	 * The FC Transport ID is a hardcoded 24-byte length
 	 */
 	return 24;
 }
 EXPORT_SYMBOL(fc_get_pr_transport_id);

 char *fc_parse_pr_out_transport_id(
 	struct se_portal_group *se_tpg,
 	const char *buf,
 	u32 *out_tid_len,
 	char **port_nexus_ptr)
 {
 	/*
 	 * The TransportID for a FC N Port is of fixed size of
 	 * 24 bytes, and FC does not contain a I_T nexus identifier,
 	 * so we return the **port_nexus_ptr set to NULL.
 	 */
 	*port_nexus_ptr = NULL;
 	*out_tid_len = 24;

 	 return (char *)&buf[8];
 }
 EXPORT_SYMBOL(fc_parse_pr_out_transport_id);

 /*
  * Handlers for Internet Small Computer Systems Interface (iSCSI)
  */

 u8 iscsi_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 {
 	/*
 	 * This value is defined for "Internet SCSI (iSCSI)"
 	 * in spc4r17 section 7.5.1 Table 362
 	 */
 	return 0x5;
 }
 EXPORT_SYMBOL(iscsi_get_fabric_proto_ident);

 u32 iscsi_get_pr_transport_id(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code,
 	unsigned char *buf)
 {
 	u32 off = 4, padding = 0;
 	u16 len = 0;

 	spin_lock_irq(&se_nacl->nacl_sess_lock);
 	/*
 	 * Set PROTOCOL IDENTIFIER to 5h for iSCSI
 	*/
 	buf[0] = 0x05;
 	/*
 	 * From spc4r17 Section 7.5.4.6: TransportID for initiator
 	 * ports using SCSI over iSCSI.
 	 *
 	 * The null-terminated, null-padded (see 4.4.2) ISCSI NAME field
 	 * shall contain the iSCSI name of an iSCSI initiator node (see
 	 * RFC 3720). The first ISCSI NAME field byte containing an ASCII
 	 * null character terminates the ISCSI NAME field without regard for
 	 * the specified length of the iSCSI TransportID or the contents of
 	 * the ADDITIONAL LENGTH field.
 	 */
 	len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
 	/*
 	 * Add Extra byte for NULL terminator
 	 */
 	len++;
 	/*
 	 * If there is ISID present with the registration and *format code == 1
 	 * 1, use iSCSI Initiator port TransportID format.
 	 *
 	 * Otherwise use iSCSI Initiator device TransportID format that
 	 * does not contain the ASCII encoded iSCSI Initiator iSID value
 	 * provied by the iSCSi Initiator during the iSCSI login process.
 	 */
 	if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
 		/*
 		 * Set FORMAT CODE 01b for iSCSI Initiator port TransportID
 		 * format.
 		 */
 		buf[0] |= 0x40;
 		/*
 		 * From spc4r17 Section 7.5.4.6: TransportID for initiator
 		 * ports using SCSI over iSCSI.  Table 390
 		 *
 		 * The SEPARATOR field shall contain the five ASCII
 		 * characters ",i,0x".
 		 *
 		 * The null-terminated, null-padded ISCSI INITIATOR SESSION ID
 		 * field shall contain the iSCSI initiator session identifier
 		 * (see RFC 3720) in the form of ASCII characters that are the
 		 * hexadecimal digits converted from the binary iSCSI initiator
 		 * session identifier value. The first ISCSI INITIATOR SESSION
 		 * ID field byte containing an ASCII null character
 		 */
 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
 		buf[off+len] = 0x69; off++; /* ASCII Character: "i" */
 		buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
 		buf[off+len] = 0x30; off++; /* ASCII Character: "0" */
 		buf[off+len] = 0x78; off++; /* ASCII Character: "x" */
 		len += 5;
 		buf[off+len] = pr_reg->pr_reg_isid[0]; off++;
 		buf[off+len] = pr_reg->pr_reg_isid[1]; off++;
 		buf[off+len] = pr_reg->pr_reg_isid[2]; off++;
 		buf[off+len] = pr_reg->pr_reg_isid[3]; off++;
 		buf[off+len] = pr_reg->pr_reg_isid[4]; off++;
 		buf[off+len] = pr_reg->pr_reg_isid[5]; off++;
 		buf[off+len] = '\0'; off++;
 		len += 7;
 	}
 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
 	/*
 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
 	 * in the TransportID. The additional length shall be at least 20 and
 	 * shall be a multiple of four.
 	*/
 	padding = ((-len) & 3);
 	if (padding != 0)
 		len += padding;

 	buf[2] = ((len >> 8) & 0xff);
 	buf[3] = (len & 0xff);
 	/*
 	 * Increment value for total payload + header length for
 	 * full status descriptor
 	 */
 	len += 4;

 	return len;
 }
 EXPORT_SYMBOL(iscsi_get_pr_transport_id);

 u32 iscsi_get_pr_transport_id_len(
 	struct se_portal_group *se_tpg,
 	struct se_node_acl *se_nacl,
 	struct t10_pr_registration *pr_reg,
 	int *format_code)
 {
 	u32 len = 0, padding = 0;

 	spin_lock_irq(&se_nacl->nacl_sess_lock);
 	len = strlen(se_nacl->initiatorname);
 	/*
 	 * Add extra byte for NULL terminator
 	 */
 	len++;
 	/*
 	 * If there is ISID present with the registration, use format code:
 	 * 01b: iSCSI Initiator port TransportID format
 	 *
 	 * If there is not an active iSCSI session, use format code:
 	 * 00b: iSCSI Initiator device TransportID format
 	 */
 	if (pr_reg->isid_present_at_reg) {
 		len += 5; /* For ",i,0x" ASCII separator */
 		len += 7; /* For iSCSI Initiator Session ID + Null terminator */
 		*format_code = 1;
 	} else
 		*format_code = 0;
 	spin_unlock_irq(&se_nacl->nacl_sess_lock);
 	/*
 	 * The ADDITIONAL LENGTH field specifies the number of bytes that follow
 	 * in the TransportID. The additional length shall be at least 20 and
 	 * shall be a multiple of four.
 	 */
 	padding = ((-len) & 3);
 	if (padding != 0)
 		len += padding;
 	/*
 	 * Increment value for total payload + header length for
 	 * full status descriptor
 	 */
 	len += 4;

 	return len;
 }
 EXPORT_SYMBOL(iscsi_get_pr_transport_id_len);

 char *iscsi_parse_pr_out_transport_id(
 	struct se_portal_group *se_tpg,
 	const char *buf,
 	u32 *out_tid_len,
 	char **port_nexus_ptr)
 {
 	char *p;
 	u32 tid_len, padding;
 	int i;
 	u16 add_len;
 	u8 format_code = (buf[0] & 0xc0);
 	/*
 	 * Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
 	 *
 	 *       TransportID for initiator ports using SCSI over iSCSI,
 	 *       from Table 388 -- iSCSI TransportID formats.
 	 *
 	 *    00b     Initiator port is identified using the world wide unique
 	 *            SCSI device name of the iSCSI initiator
 	 *            device containing the initiator port (see table 389).
 	 *    01b     Initiator port is identified using the world wide unique
 	 *            initiator port identifier (see table 390).10b to 11b
 	 *            Reserved
 	 */
 	if ((format_code != 0x00) && (format_code != 0x40)) {
 		pr_err("Illegal format code: 0x%02x for iSCSI"
 			" Initiator Transport ID\n", format_code);
 		return NULL;
 	}
 	/*
 	 * If the caller wants the TransportID Length, we set that value for the
 	 * entire iSCSI Tarnsport ID now.
 	 */
 	 if (out_tid_len != NULL) {
 		add_len = ((buf[2] >> 8) & 0xff);
 		add_len |= (buf[3] & 0xff);

 		tid_len = strlen(&buf[4]);
 		tid_len += 4; /* Add four bytes for iSCSI Transport ID header */
 		tid_len += 1; /* Add one byte for NULL terminator */
 		padding = ((-tid_len) & 3);
 		if (padding != 0)
 			tid_len += padding;

 		if ((add_len + 4) != tid_len) {
 			pr_debug("LIO-Target Extracted add_len: %hu "
 				"does not match calculated tid_len: %u,"
 				" using tid_len instead\n", add_len+4, tid_len);
 			*out_tid_len = tid_len;
 		} else
 			*out_tid_len = (add_len + 4);
 	}
 	/*
 	 * Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
 	 * Session ID as defined in Table 390 - iSCSI initiator port TransportID
 	 * format.
 	 */
 	if (format_code == 0x40) {
 		p = strstr(&buf[4], ",i,0x");
 		if (!p) {
 			pr_err("Unable to locate \",i,0x\" separator"
 				" for Initiator port identifier: %s\n",
 				&buf[4]);
 			return NULL;
 		}
 		*p = '\0'; /* Terminate iSCSI Name */
 		p += 5; /* Skip over ",i,0x" separator */

 		*port_nexus_ptr = p;
 		/*
 		 * Go ahead and do the lower case conversion of the received
 		 * 12 ASCII characters representing the ISID in the TransportID
 		 * for comparison against the running iSCSI session's ISID from
 		 * iscsi_target.c:lio_sess_get_initiator_sid()
 		 */
 		for (i = 0; i < 12; i++) {
 			if (isdigit(*p)) {
 				p++;
 				continue;
 			}
 			*p = tolower(*p);
 			p++;
 		}
 	}

 	return (char *)&buf[4];
 }
 EXPORT_SYMBOL(iscsi_parse_pr_out_transport_id);
	/*******************************************************************************
	* Filename: target_core_fabric_lib.c
	*
	* This file contains generic high level protocol identifier and PR
	* handlers for TCM fabric modules
	*
	* (c) Copyright 2010-2013 Datera, Inc.
	*
	* Nicholas A. Bellinger <nab@linux-iscsi.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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*
	******************************************************************************/

	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/ctype.h>
	#include <linux/spinlock.h>
	#include <linux/export.h>
	#include <scsi/scsi.h>
	#include <scsi/scsi_cmnd.h>

	#include <target/target_core_base.h>
	#include <target/target_core_fabric.h>
	#include <target/target_core_configfs.h>

	#include "target_core_internal.h"
	#include "target_core_pr.h"

	/*
	* Handlers for Serial Attached SCSI (SAS)
	*/
	u8 sas_get_fabric_proto_ident(struct se_portal_group *se_tpg)
	{
	/*
	* Return a SAS Serial SCSI Protocol identifier for loopback operations
	* This is defined in section 7.5.1 Table 362 in spc4r17
	*/
	return 0x6;
	}
	EXPORT_SYMBOL(sas_get_fabric_proto_ident);

	u32 sas_get_pr_transport_id(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code,
	unsigned char *buf)
	{
	unsigned char *ptr;
	int ret;

	/*
	* Set PROTOCOL IDENTIFIER to 6h for SAS
	*/
	buf[0] = 0x06;
	/*
	* From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
	* over SAS Serial SCSI Protocol
	*/
	ptr = &se_nacl->initiatorname[4]; /* Skip over 'naa. prefix */

	ret = hex2bin(&buf[4], ptr, 8);
	if (ret < 0)
	pr_debug("sas transport_id: invalid hex string\n");

	/*
	* The SAS Transport ID is a hardcoded 24-byte length
	*/
	return 24;
	}
	EXPORT_SYMBOL(sas_get_pr_transport_id);

	u32 sas_get_pr_transport_id_len(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code)
	{
	*format_code = 0;
	/*
	* From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
	* over SAS Serial SCSI Protocol
	*
	* The SAS Transport ID is a hardcoded 24-byte length
	*/
	return 24;
	}
	EXPORT_SYMBOL(sas_get_pr_transport_id_len);

	/*
	* Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
	* Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
	*/
	char *sas_parse_pr_out_transport_id(
	struct se_portal_group *se_tpg,
	const char *buf,
	u32 *out_tid_len,
	char **port_nexus_ptr)
	{
	/*
	* Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
	* for initiator ports using SCSI over SAS Serial SCSI Protocol
	*
	* The TransportID for a SAS Initiator Port is of fixed size of
	* 24 bytes, and SAS does not contain a I_T nexus identifier,
	* so we return the **port_nexus_ptr set to NULL.
	*/
	*port_nexus_ptr = NULL;
	*out_tid_len = 24;

	return (char *)&buf[4];
	}
	EXPORT_SYMBOL(sas_parse_pr_out_transport_id);

	/*
	* Handlers for Fibre Channel Protocol (FCP)
	*/
	u8 fc_get_fabric_proto_ident(struct se_portal_group *se_tpg)
	{
	return 0x0; /* 0 = fcp-2 per SPC4 section 7.5.1 */
	}
	EXPORT_SYMBOL(fc_get_fabric_proto_ident);

	u32 fc_get_pr_transport_id_len(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code)
	{
	*format_code = 0;
	/*
	* The FC Transport ID is a hardcoded 24-byte length
	*/
	return 24;
	}
	EXPORT_SYMBOL(fc_get_pr_transport_id_len);

	u32 fc_get_pr_transport_id(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code,
	unsigned char *buf)
	{
	unsigned char *ptr;
	int i, ret;
	u32 off = 8;

	/*
	* PROTOCOL IDENTIFIER is 0h for FCP-2
	*
	* From spc4r17, 7.5.4.2 TransportID for initiator ports using
	* SCSI over Fibre Channel
	*
	* We convert the ASCII formatted N Port name into a binary
	* encoded TransportID.
	*/
	ptr = &se_nacl->initiatorname[0];

	for (i = 0; i < 24; ) {
	if (!strncmp(&ptr[i], ":", 1)) {
	i++;
	continue;
	}
	ret = hex2bin(&buf[off++], &ptr[i], 1);
	if (ret < 0)
	pr_debug("fc transport_id: invalid hex string\n");
	i += 2;
	}
	/*
	* The FC Transport ID is a hardcoded 24-byte length
	*/
	return 24;
	}
	EXPORT_SYMBOL(fc_get_pr_transport_id);

	char *fc_parse_pr_out_transport_id(
	struct se_portal_group *se_tpg,
	const char *buf,
	u32 *out_tid_len,
	char **port_nexus_ptr)
	{
	/*
	* The TransportID for a FC N Port is of fixed size of
	* 24 bytes, and FC does not contain a I_T nexus identifier,
	* so we return the **port_nexus_ptr set to NULL.
	*/
	*port_nexus_ptr = NULL;
	*out_tid_len = 24;

	return (char *)&buf[8];
	}
	EXPORT_SYMBOL(fc_parse_pr_out_transport_id);

	/*
	* Handlers for Internet Small Computer Systems Interface (iSCSI)
	*/

	u8 iscsi_get_fabric_proto_ident(struct se_portal_group *se_tpg)
	{
	/*
	* This value is defined for "Internet SCSI (iSCSI)"
	* in spc4r17 section 7.5.1 Table 362
	*/
	return 0x5;
	}
	EXPORT_SYMBOL(iscsi_get_fabric_proto_ident);

	u32 iscsi_get_pr_transport_id(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code,
	unsigned char *buf)
	{
	u32 off = 4, padding = 0;
	u16 len = 0;

	spin_lock_irq(&se_nacl->nacl_sess_lock);
	/*
	* Set PROTOCOL IDENTIFIER to 5h for iSCSI
	*/
	buf[0] = 0x05;
	/*
	* From spc4r17 Section 7.5.4.6: TransportID for initiator
	* ports using SCSI over iSCSI.
	*
	* The null-terminated, null-padded (see 4.4.2) ISCSI NAME field
	* shall contain the iSCSI name of an iSCSI initiator node (see
	* RFC 3720). The first ISCSI NAME field byte containing an ASCII
	* null character terminates the ISCSI NAME field without regard for
	* the specified length of the iSCSI TransportID or the contents of
	* the ADDITIONAL LENGTH field.
	*/
	len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
	/*
	* Add Extra byte for NULL terminator
	*/
	len++;
	/*
	* If there is ISID present with the registration and *format code == 1
	* 1, use iSCSI Initiator port TransportID format.
	*
	* Otherwise use iSCSI Initiator device TransportID format that
	* does not contain the ASCII encoded iSCSI Initiator iSID value
	* provied by the iSCSi Initiator during the iSCSI login process.
	*/
	if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
	/*
	* Set FORMAT CODE 01b for iSCSI Initiator port TransportID
	* format.
	*/
	buf[0] \|= 0x40;
	/*
	* From spc4r17 Section 7.5.4.6: TransportID for initiator
	* ports using SCSI over iSCSI. Table 390
	*
	* The SEPARATOR field shall contain the five ASCII
	* characters ",i,0x".
	*
	* The null-terminated, null-padded ISCSI INITIATOR SESSION ID
	* field shall contain the iSCSI initiator session identifier
	* (see RFC 3720) in the form of ASCII characters that are the
	* hexadecimal digits converted from the binary iSCSI initiator
	* session identifier value. The first ISCSI INITIATOR SESSION
	* ID field byte containing an ASCII null character
	*/
	buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
	buf[off+len] = 0x69; off++; /* ASCII Character: "i" */
	buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
	buf[off+len] = 0x30; off++; /* ASCII Character: "0" */
	buf[off+len] = 0x78; off++; /* ASCII Character: "x" */
	len += 5;
	buf[off+len] = pr_reg->pr_reg_isid[0]; off++;
	buf[off+len] = pr_reg->pr_reg_isid[1]; off++;
	buf[off+len] = pr_reg->pr_reg_isid[2]; off++;
	buf[off+len] = pr_reg->pr_reg_isid[3]; off++;
	buf[off+len] = pr_reg->pr_reg_isid[4]; off++;
	buf[off+len] = pr_reg->pr_reg_isid[5]; off++;
	buf[off+len] = '\0'; off++;
	len += 7;
	}
	spin_unlock_irq(&se_nacl->nacl_sess_lock);
	/*
	* The ADDITIONAL LENGTH field specifies the number of bytes that follow
	* in the TransportID. The additional length shall be at least 20 and
	* shall be a multiple of four.
	*/
	padding = ((-len) & 3);
	if (padding != 0)
	len += padding;

	buf[2] = ((len >> 8) & 0xff);
	buf[3] = (len & 0xff);
	/*
	* Increment value for total payload + header length for
	* full status descriptor
	*/
	len += 4;

	return len;
	}
	EXPORT_SYMBOL(iscsi_get_pr_transport_id);

	u32 iscsi_get_pr_transport_id_len(
	struct se_portal_group *se_tpg,
	struct se_node_acl *se_nacl,
	struct t10_pr_registration *pr_reg,
	int *format_code)
	{
	u32 len = 0, padding = 0;

	spin_lock_irq(&se_nacl->nacl_sess_lock);
	len = strlen(se_nacl->initiatorname);
	/*
	* Add extra byte for NULL terminator
	*/
	len++;
	/*
	* If there is ISID present with the registration, use format code:
	* 01b: iSCSI Initiator port TransportID format
	*
	* If there is not an active iSCSI session, use format code:
	* 00b: iSCSI Initiator device TransportID format
	*/
	if (pr_reg->isid_present_at_reg) {
	len += 5; /* For ",i,0x" ASCII separator */
	len += 7; /* For iSCSI Initiator Session ID + Null terminator */
	*format_code = 1;
	} else
	*format_code = 0;
	spin_unlock_irq(&se_nacl->nacl_sess_lock);
	/*
	* The ADDITIONAL LENGTH field specifies the number of bytes that follow
	* in the TransportID. The additional length shall be at least 20 and
	* shall be a multiple of four.
	*/
	padding = ((-len) & 3);
	if (padding != 0)
	len += padding;
	/*
	* Increment value for total payload + header length for
	* full status descriptor
	*/
	len += 4;

	return len;
	}
	EXPORT_SYMBOL(iscsi_get_pr_transport_id_len);

	char *iscsi_parse_pr_out_transport_id(
	struct se_portal_group *se_tpg,
	const char *buf,
	u32 *out_tid_len,
	char **port_nexus_ptr)
	{
	char *p;
	u32 tid_len, padding;
	int i;
	u16 add_len;
	u8 format_code = (buf[0] & 0xc0);
	/*
	* Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
	*
	* TransportID for initiator ports using SCSI over iSCSI,
	* from Table 388 -- iSCSI TransportID formats.
	*
	* 00b Initiator port is identified using the world wide unique
	* SCSI device name of the iSCSI initiator
	* device containing the initiator port (see table 389).
	* 01b Initiator port is identified using the world wide unique
	* initiator port identifier (see table 390).10b to 11b
	* Reserved
	*/
	if ((format_code != 0x00) && (format_code != 0x40)) {
	pr_err("Illegal format code: 0x%02x for iSCSI"
	" Initiator Transport ID\n", format_code);
	return NULL;
	}
	/*
	* If the caller wants the TransportID Length, we set that value for the
	* entire iSCSI Tarnsport ID now.
	*/
	if (out_tid_len != NULL) {
	add_len = ((buf[2] >> 8) & 0xff);
	add_len \|= (buf[3] & 0xff);

	tid_len = strlen(&buf[4]);
	tid_len += 4; /* Add four bytes for iSCSI Transport ID header */
	tid_len += 1; /* Add one byte for NULL terminator */
	padding = ((-tid_len) & 3);
	if (padding != 0)
	tid_len += padding;

	if ((add_len + 4) != tid_len) {
	pr_debug("LIO-Target Extracted add_len: %hu "
	"does not match calculated tid_len: %u,"
	" using tid_len instead\n", add_len+4, tid_len);
	*out_tid_len = tid_len;
	} else
	*out_tid_len = (add_len + 4);
	}
	/*
	* Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
	* Session ID as defined in Table 390 - iSCSI initiator port TransportID
	* format.
	*/
	if (format_code == 0x40) {
	p = strstr(&buf[4], ",i,0x");
	if (!p) {
	pr_err("Unable to locate \",i,0x\" separator"
	" for Initiator port identifier: %s\n",
	&buf[4]);
	return NULL;
	}
	p = '\0'; / Terminate iSCSI Name */
	p += 5; /* Skip over ",i,0x" separator */

	*port_nexus_ptr = p;
	/*
	* Go ahead and do the lower case conversion of the received
	* 12 ASCII characters representing the ISID in the TransportID
	* for comparison against the running iSCSI session's ISID from
	* iscsi_target.c:lio_sess_get_initiator_sid()
	*/
	for (i = 0; i < 12; i++) {
	if (isdigit(*p)) {
	p++;
	continue;
	}
	p = tolower(p);
	p++;
	}
	}

	return (char *)&buf[4];
	}
	EXPORT_SYMBOL(iscsi_parse_pr_out_transport_id);