kernel / drivers / target / iscsi / iscsi_target_login.c

/*******************************************************************************
 * This file contains the login functions used by the iSCSI Target driver.
 *
 * (c) Copyright 2007-2013 Datera, Inc.
 *
 * Author: Nicholas A. Bellinger <[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.
 ******************************************************************************/

#include <crypto/hash.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kthread.h>
#include <linux/sched/signal.h>
#include <linux/idr.h>
#include <linux/tcp.h>        /* TCP_NODELAY */
#include <net/ipv6.h>         /* ipv6_addr_v4mapped() */
#include <scsi/iscsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>

#include <target/iscsi/iscsi_target_core.h>
#include <target/iscsi/iscsi_target_stat.h>
#include "iscsi_target_device.h"
#include "iscsi_target_nego.h"
#include "iscsi_target_erl0.h"
#include "iscsi_target_erl2.h"
#include "iscsi_target_login.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"
#include "iscsi_target.h"
#include "iscsi_target_parameters.h"

#include <target/iscsi/iscsi_transport.h>

static struct iscsi_login *iscsi_login_init_conn(struct iscsi_conn *conn)
{
	struct iscsi_login *login;

	login = kzalloc(sizeof(struct iscsi_login), GFP_KERNEL);
	if (!login) {
		pr_err("Unable to allocate memory for struct iscsi_login.\n");
		return NULL;
	}
	conn->login = login;
	login->conn = conn;
	login->first_request = 1;

	login->req_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
	if (!login->req_buf) {
		pr_err("Unable to allocate memory for response buffer.\n");
		goto out_login;
	}

	login->rsp_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
	if (!login->rsp_buf) {
		pr_err("Unable to allocate memory for request buffer.\n");
		goto out_req_buf;
	}

	conn->conn_ops = kzalloc(sizeof(struct iscsi_conn_ops), GFP_KERNEL);
	if (!conn->conn_ops) {
		pr_err("Unable to allocate memory for"
			" struct iscsi_conn_ops.\n");
		goto out_rsp_buf;
	}

	init_waitqueue_head(&conn->queues_wq);
	INIT_LIST_HEAD(&conn->conn_list);
	INIT_LIST_HEAD(&conn->conn_cmd_list);
	INIT_LIST_HEAD(&conn->immed_queue_list);
	INIT_LIST_HEAD(&conn->response_queue_list);
	init_completion(&conn->conn_post_wait_comp);
	init_completion(&conn->conn_wait_comp);
	init_completion(&conn->conn_wait_rcfr_comp);
	init_completion(&conn->conn_waiting_on_uc_comp);
	init_completion(&conn->conn_logout_comp);
	init_completion(&conn->rx_half_close_comp);
	init_completion(&conn->tx_half_close_comp);
	init_completion(&conn->rx_login_comp);
	spin_lock_init(&conn->cmd_lock);
	spin_lock_init(&conn->conn_usage_lock);
	spin_lock_init(&conn->immed_queue_lock);
	spin_lock_init(&conn->nopin_timer_lock);
	spin_lock_init(&conn->response_queue_lock);
	spin_lock_init(&conn->state_lock);

	if (!zalloc_cpumask_var(&conn->conn_cpumask, GFP_KERNEL)) {
		pr_err("Unable to allocate conn->conn_cpumask\n");
		goto out_conn_ops;
	}
	conn->conn_login = login;

	return login;

out_conn_ops:
	kfree(conn->conn_ops);
out_rsp_buf:
	kfree(login->rsp_buf);
out_req_buf:
	kfree(login->req_buf);
out_login:
	kfree(login);
	return NULL;
}

/*
 * Used by iscsi_target_nego.c:iscsi_target_locate_portal() to setup
 * per struct iscsi_conn libcrypto contexts for crc32c and crc32-intel
 */
int iscsi_login_setup_crypto(struct iscsi_conn *conn)
{
	struct crypto_ahash *tfm;

	/*
	 * Setup slicing by CRC32C algorithm for RX and TX libcrypto contexts
	 * which will default to crc32c_intel.ko for cpu_has_xmm4_2, or fallback
	 * to software 1x8 byte slicing from crc32c.ko
	 */
	tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(tfm)) {
		pr_err("crypto_alloc_ahash() failed\n");
		return -ENOMEM;
	}

	conn->conn_rx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!conn->conn_rx_hash) {
		pr_err("ahash_request_alloc() failed for conn_rx_hash\n");
		crypto_free_ahash(tfm);
		return -ENOMEM;
	}
	ahash_request_set_callback(conn->conn_rx_hash, 0, NULL, NULL);

	conn->conn_tx_hash = ahash_request_alloc(tfm, GFP_KERNEL);
	if (!conn->conn_tx_hash) {
		pr_err("ahash_request_alloc() failed for conn_tx_hash\n");
		ahash_request_free(conn->conn_rx_hash);
		conn->conn_rx_hash = NULL;
		crypto_free_ahash(tfm);
		return -ENOMEM;
	}
	ahash_request_set_callback(conn->conn_tx_hash, 0, NULL, NULL);

	return 0;
}

static int iscsi_login_check_initiator_version(
	struct iscsi_conn *conn,
	u8 version_max,
	u8 version_min)
{
	if ((version_max != 0x00) || (version_min != 0x00)) {
		pr_err("Unsupported iSCSI IETF Pre-RFC Revision,"
			" version Min/Max 0x%02x/0x%02x, rejecting login.\n",
			version_min, version_max);
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
				ISCSI_LOGIN_STATUS_NO_VERSION);
		return -1;
	}

	return 0;
}

int iscsi_check_for_session_reinstatement(struct iscsi_conn *conn)
{
	int sessiontype;
	struct iscsi_param *initiatorname_param = NULL, *sessiontype_param = NULL;
	struct iscsi_portal_group *tpg = conn->tpg;
	struct iscsi_session *sess = NULL, *sess_p = NULL;
	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
	struct se_session *se_sess, *se_sess_tmp;

	initiatorname_param = iscsi_find_param_from_key(
			INITIATORNAME, conn->param_list);
	sessiontype_param = iscsi_find_param_from_key(
			SESSIONTYPE, conn->param_list);
	if (!initiatorname_param || !sessiontype_param) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
		return -1;
	}

	sessiontype = (strncmp(sessiontype_param->value, NORMAL, 6)) ? 1 : 0;

	spin_lock_bh(&se_tpg->session_lock);
	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
			sess_list) {

		sess_p = se_sess->fabric_sess_ptr;
		spin_lock(&sess_p->conn_lock);
		if (atomic_read(&sess_p->session_fall_back_to_erl0) ||
		    atomic_read(&sess_p->session_logout) ||
		    (sess_p->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
			spin_unlock(&sess_p->conn_lock);
			continue;
		}
		if (!memcmp(sess_p->isid, conn->sess->isid, 6) &&
		   (!strcmp(sess_p->sess_ops->InitiatorName,
			    initiatorname_param->value) &&
		   (sess_p->sess_ops->SessionType == sessiontype))) {
			atomic_set(&sess_p->session_reinstatement, 1);
			spin_unlock(&sess_p->conn_lock);
			iscsit_inc_session_usage_count(sess_p);
			iscsit_stop_time2retain_timer(sess_p);
			sess = sess_p;
			break;
		}
		spin_unlock(&sess_p->conn_lock);
	}
	spin_unlock_bh(&se_tpg->session_lock);
	/*
	 * If the Time2Retain handler has expired, the session is already gone.
	 */
	if (!sess)
		return 0;

	pr_debug("%s iSCSI Session SID %u is still active for %s,"
		" performing session reinstatement.\n", (sessiontype) ?
		"Discovery" : "Normal", sess->sid,
		sess->sess_ops->InitiatorName);

	spin_lock_bh(&sess->conn_lock);
	if (sess->session_state == TARG_SESS_STATE_FAILED) {
		spin_unlock_bh(&sess->conn_lock);
		iscsit_dec_session_usage_count(sess);
		iscsit_close_session(sess);
		return 0;
	}
	spin_unlock_bh(&sess->conn_lock);

	iscsit_stop_session(sess, 1, 1);
	iscsit_dec_session_usage_count(sess);

	iscsit_close_session(sess);
	return 0;
}

static void iscsi_login_set_conn_values(
	struct iscsi_session *sess,
	struct iscsi_conn *conn,
	__be16 cid)
{
	conn->sess		= sess;
	conn->cid		= be16_to_cpu(cid);
	/*
	 * Generate a random Status sequence number (statsn) for the new
	 * iSCSI connection.
	 */
	get_random_bytes(&conn->stat_sn, sizeof(u32));

	mutex_lock(&auth_id_lock);
	conn->auth_id		= iscsit_global->auth_id++;
	mutex_unlock(&auth_id_lock);
}

__printf(2, 3) int iscsi_change_param_sprintf(
	struct iscsi_conn *conn,
	const char *fmt, ...)
{
	va_list args;
	unsigned char buf[64];

	memset(buf, 0, sizeof buf);

	va_start(args, fmt);
	vsnprintf(buf, sizeof buf, fmt, args);
	va_end(args);

	if (iscsi_change_param_value(buf, conn->param_list, 0) < 0) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		return -1;
	}

	return 0;
}
EXPORT_SYMBOL(iscsi_change_param_sprintf);

/*
 *	This is the leading connection of a new session,
 *	or session reinstatement.
 */
static int iscsi_login_zero_tsih_s1(
	struct iscsi_conn *conn,
	unsigned char *buf)
{
	struct iscsi_session *sess = NULL;
	struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;
	int ret;

	sess = kzalloc(sizeof(struct iscsi_session), GFP_KERNEL);
	if (!sess) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		pr_err("Could not allocate memory for session\n");
		return -ENOMEM;
	}

	iscsi_login_set_conn_values(sess, conn, pdu->cid);
	sess->init_task_tag	= pdu->itt;
	memcpy(&sess->isid, pdu->isid, 6);
	sess->exp_cmd_sn	= be32_to_cpu(pdu->cmdsn);
	INIT_LIST_HEAD(&sess->sess_conn_list);
	INIT_LIST_HEAD(&sess->sess_ooo_cmdsn_list);
	INIT_LIST_HEAD(&sess->cr_active_list);
	INIT_LIST_HEAD(&sess->cr_inactive_list);
	init_completion(&sess->async_msg_comp);
	init_completion(&sess->reinstatement_comp);
	init_completion(&sess->session_wait_comp);
	init_completion(&sess->session_waiting_on_uc_comp);
	mutex_init(&sess->cmdsn_mutex);
	spin_lock_init(&sess->conn_lock);
	spin_lock_init(&sess->cr_a_lock);
	spin_lock_init(&sess->cr_i_lock);
	spin_lock_init(&sess->session_usage_lock);
	spin_lock_init(&sess->ttt_lock);

	idr_preload(GFP_KERNEL);
	spin_lock_bh(&sess_idr_lock);
	ret = idr_alloc(&sess_idr, NULL, 0, 0, GFP_NOWAIT);
	if (ret >= 0)
		sess->session_index = ret;
	spin_unlock_bh(&sess_idr_lock);
	idr_preload_end();

	if (ret < 0) {
		pr_err("idr_alloc() for sess_idr failed\n");
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		kfree(sess);
		return -ENOMEM;
	}

	sess->creation_time = get_jiffies_64();
	/*
	 * The FFP CmdSN window values will be allocated from the TPG's
	 * Initiator Node's ACL once the login has been successfully completed.
	 */
	atomic_set(&sess->max_cmd_sn, be32_to_cpu(pdu->cmdsn));

	sess->sess_ops = kzalloc(sizeof(struct iscsi_sess_ops), GFP_KERNEL);
	if (!sess->sess_ops) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		pr_err("Unable to allocate memory for"
				" struct iscsi_sess_ops.\n");
		kfree(sess);
		return -ENOMEM;
	}

	sess->se_sess = transport_init_session(TARGET_PROT_NORMAL);
	if (IS_ERR(sess->se_sess)) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		kfree(sess->sess_ops);
		kfree(sess);
		return -ENOMEM;
	}

	return 0;
}

static int iscsi_login_zero_tsih_s2(
	struct iscsi_conn *conn)
{
	struct iscsi_node_attrib *na;
	struct iscsi_session *sess = conn->sess;
	bool iser = false;

	sess->tpg = conn->tpg;

	/*
	 * Assign a new TPG Session Handle.  Note this is protected with
	 * struct iscsi_portal_group->np_login_sem from iscsit_access_np().
	 */
	sess->tsih = ++sess->tpg->ntsih;
	if (!sess->tsih)
		sess->tsih = ++sess->tpg->ntsih;

	/*
	 * Create the default params from user defined values..
	 */
	if (iscsi_copy_param_list(&conn->param_list,
				conn->tpg->param_list, 1) < 0) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		return -1;
	}

	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
		iser = true;

	iscsi_set_keys_to_negotiate(conn->param_list, iser);

	if (sess->sess_ops->SessionType)
		return iscsi_set_keys_irrelevant_for_discovery(
				conn->param_list);

	na = iscsit_tpg_get_node_attrib(sess);

	/*
	 * Need to send TargetPortalGroupTag back in first login response
	 * on any iSCSI connection where the Initiator provides TargetName.
	 * See 5.3.1.  Login Phase Start
	 *
	 * In our case, we have already located the struct iscsi_tiqn at this point.
	 */
	if (iscsi_change_param_sprintf(conn, "TargetPortalGroupTag=%hu", sess->tpg->tpgt))
		return -1;

	/*
	 * Workaround for Initiators that have broken connection recovery logic.
	 *
	 * "We would really like to get rid of this." Linux-iSCSI.org team
	 */
	if (iscsi_change_param_sprintf(conn, "ErrorRecoveryLevel=%d", na->default_erl))
		return -1;

	/*
	 * Set RDMAExtensions=Yes by default for iSER enabled network portals
	 */
	if (iser) {
		struct iscsi_param *param;
		unsigned long mrdsl, off;
		int rc;

		if (iscsi_change_param_sprintf(conn, "RDMAExtensions=Yes"))
			return -1;

		/*
		 * Make MaxRecvDataSegmentLength PAGE_SIZE aligned for
		 * Immediate Data + Unsolicited Data-OUT if necessary..
		 */
		param = iscsi_find_param_from_key("MaxRecvDataSegmentLength",
						  conn->param_list);
		if (!param) {
			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
			return -1;
		}
		rc = kstrtoul(param->value, 0, &mrdsl);
		if (rc < 0) {
			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
			return -1;
		}
		off = mrdsl % PAGE_SIZE;
		if (!off)
			goto check_prot;

		if (mrdsl < PAGE_SIZE)
			mrdsl = PAGE_SIZE;
		else
			mrdsl -= off;

		pr_warn("Aligning ISER MaxRecvDataSegmentLength: %lu down"
			" to PAGE_SIZE\n", mrdsl);

		if (iscsi_change_param_sprintf(conn, "MaxRecvDataSegmentLength=%lu\n", mrdsl))
			return -1;
		/*
		 * ISER currently requires that ImmediateData + Unsolicited
		 * Data be disabled when protection / signature MRs are enabled.
		 */
check_prot:
		if (sess->se_sess->sup_prot_ops &
		   (TARGET_PROT_DOUT_STRIP | TARGET_PROT_DOUT_PASS |
		    TARGET_PROT_DOUT_INSERT)) {

			if (iscsi_change_param_sprintf(conn, "ImmediateData=No"))
				return -1;

			if (iscsi_change_param_sprintf(conn, "InitialR2T=Yes"))
				return -1;

			pr_debug("Forcing ImmediateData=No + InitialR2T=Yes for"
				 " T10-PI enabled ISER session\n");
		}
	}

	return 0;
}

static int iscsi_login_non_zero_tsih_s1(
	struct iscsi_conn *conn,
	unsigned char *buf)
{
	struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;

	iscsi_login_set_conn_values(NULL, conn, pdu->cid);
	return 0;
}

/*
 *	Add a new connection to an existing session.
 */
static int iscsi_login_non_zero_tsih_s2(
	struct iscsi_conn *conn,
	unsigned char *buf)
{
	struct iscsi_portal_group *tpg = conn->tpg;
	struct iscsi_session *sess = NULL, *sess_p = NULL;
	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
	struct se_session *se_sess, *se_sess_tmp;
	struct iscsi_login_req *pdu = (struct iscsi_login_req *)buf;
	bool iser = false;

	spin_lock_bh(&se_tpg->session_lock);
	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
			sess_list) {

		sess_p = (struct iscsi_session *)se_sess->fabric_sess_ptr;
		if (atomic_read(&sess_p->session_fall_back_to_erl0) ||
		    atomic_read(&sess_p->session_logout) ||
		   (sess_p->time2retain_timer_flags & ISCSI_TF_EXPIRED))
			continue;
		if (!memcmp(sess_p->isid, pdu->isid, 6) &&
		     (sess_p->tsih == be16_to_cpu(pdu->tsih))) {
			iscsit_inc_session_usage_count(sess_p);
			iscsit_stop_time2retain_timer(sess_p);
			sess = sess_p;
			break;
		}
	}
	spin_unlock_bh(&se_tpg->session_lock);

	/*
	 * If the Time2Retain handler has expired, the session is already gone.
	 */
	if (!sess) {
		pr_err("Initiator attempting to add a connection to"
			" a non-existent session, rejecting iSCSI Login.\n");
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
				ISCSI_LOGIN_STATUS_NO_SESSION);
		return -1;
	}

	/*
	 * Stop the Time2Retain timer if this is a failed session, we restart
	 * the timer if the login is not successful.
	 */
	spin_lock_bh(&sess->conn_lock);
	if (sess->session_state == TARG_SESS_STATE_FAILED)
		atomic_set(&sess->session_continuation, 1);
	spin_unlock_bh(&sess->conn_lock);

	iscsi_login_set_conn_values(sess, conn, pdu->cid);

	if (iscsi_copy_param_list(&conn->param_list,
			conn->tpg->param_list, 0) < 0) {
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_NO_RESOURCES);
		return -1;
	}

	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
		iser = true;

	iscsi_set_keys_to_negotiate(conn->param_list, iser);
	/*
	 * Need to send TargetPortalGroupTag back in first login response
	 * on any iSCSI connection where the Initiator provides TargetName.
	 * See 5.3.1.  Login Phase Start
	 *
	 * In our case, we have already located the struct iscsi_tiqn at this point.
	 */
	if (iscsi_change_param_sprintf(conn, "TargetPortalGroupTag=%hu", sess->tpg->tpgt))
		return -1;

	return 0;
}

int iscsi_login_post_auth_non_zero_tsih(
	struct iscsi_conn *conn,
	u16 cid,
	u32 exp_statsn)
{
	struct iscsi_conn *conn_ptr = NULL;
	struct iscsi_conn_recovery *cr = NULL;
	struct iscsi_session *sess = conn->sess;

	/*
	 * By following item 5 in the login table,  if we have found
	 * an existing ISID and a valid/existing TSIH and an existing
	 * CID we do connection reinstatement.  Currently we dont not
	 * support it so we send back an non-zero status class to the
	 * initiator and release the new connection.
	 */
	conn_ptr = iscsit_get_conn_from_cid_rcfr(sess, cid);
	if (conn_ptr) {
		pr_err("Connection exists with CID %hu for %s,"
			" performing connection reinstatement.\n",
			conn_ptr->cid, sess->sess_ops->InitiatorName);

		iscsit_connection_reinstatement_rcfr(conn_ptr);
		iscsit_dec_conn_usage_count(conn_ptr);
	}

	/*
	 * Check for any connection recovery entires containing CID.
	 * We use the original ExpStatSN sent in the first login request
	 * to acknowledge commands for the failed connection.
	 *
	 * Also note that an explict logout may have already been sent,
	 * but the response may not be sent due to additional connection
	 * loss.
	 */
	if (sess->sess_ops->ErrorRecoveryLevel == 2) {
		cr = iscsit_get_inactive_connection_recovery_entry(
				sess, cid);
		if (cr) {
			pr_debug("Performing implicit logout"
				" for connection recovery on CID: %hu\n",
					conn->cid);
			iscsit_discard_cr_cmds_by_expstatsn(cr, exp_statsn);
		}
	}

	/*
	 * Else we follow item 4 from the login table in that we have
	 * found an existing ISID and a valid/existing TSIH and a new
	 * CID we go ahead and continue to add a new connection to the
	 * session.
	 */
	pr_debug("Adding CID %hu to existing session for %s.\n",
			cid, sess->sess_ops->InitiatorName);

	if ((atomic_read(&sess->nconn) + 1) > sess->sess_ops->MaxConnections) {
		pr_err("Adding additional connection to this session"
			" would exceed MaxConnections %d, login failed.\n",
				sess->sess_ops->MaxConnections);
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
				ISCSI_LOGIN_STATUS_ISID_ERROR);
		return -1;
	}

	return 0;
}

static void iscsi_post_login_start_timers(struct iscsi_conn *conn)
{
	struct iscsi_session *sess = conn->sess;
	/*
	 * FIXME: Unsolicited NopIN support for ISER
	 */
	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND)
		return;

	if (!sess->sess_ops->SessionType)
		iscsit_start_nopin_timer(conn);
}

int iscsit_start_kthreads(struct iscsi_conn *conn)
{
	int ret = 0;

	spin_lock(&iscsit_global->ts_bitmap_lock);
	conn->bitmap_id = bitmap_find_free_region(iscsit_global->ts_bitmap,
					ISCSIT_BITMAP_BITS, get_order(1));
	spin_unlock(&iscsit_global->ts_bitmap_lock);

	if (conn->bitmap_id < 0) {
		pr_err("bitmap_find_free_region() failed for"
		       " iscsit_start_kthreads()\n");
		return -ENOMEM;
	}

	conn->tx_thread = kthread_run(iscsi_target_tx_thread, conn,
				      "%s", ISCSI_TX_THREAD_NAME);
	if (IS_ERR(conn->tx_thread)) {
		pr_err("Unable to start iscsi_target_tx_thread\n");
		ret = PTR_ERR(conn->tx_thread);
		goto out_bitmap;
	}
	conn->tx_thread_active = true;

	conn->rx_thread = kthread_run(iscsi_target_rx_thread, conn,
				      "%s", ISCSI_RX_THREAD_NAME);
	if (IS_ERR(conn->rx_thread)) {
		pr_err("Unable to start iscsi_target_rx_thread\n");
		ret = PTR_ERR(conn->rx_thread);
		goto out_tx;
	}
	conn->rx_thread_active = true;

	return 0;
out_tx:
	send_sig(SIGINT, conn->tx_thread, 1);
	kthread_stop(conn->tx_thread);
	conn->tx_thread_active = false;
out_bitmap:
	spin_lock(&iscsit_global->ts_bitmap_lock);
	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
			      get_order(1));
	spin_unlock(&iscsit_global->ts_bitmap_lock);
	return ret;
}

void iscsi_post_login_handler(
	struct iscsi_np *np,
	struct iscsi_conn *conn,
	u8 zero_tsih)
{
	int stop_timer = 0;
	struct iscsi_session *sess = conn->sess;
	struct se_session *se_sess = sess->se_sess;
	struct iscsi_portal_group *tpg = sess->tpg;
	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;

	iscsit_inc_conn_usage_count(conn);

	iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_SUCCESS,
			ISCSI_LOGIN_STATUS_ACCEPT);

	pr_debug("Moving to TARG_CONN_STATE_LOGGED_IN.\n");
	conn->conn_state = TARG_CONN_STATE_LOGGED_IN;

	iscsi_set_connection_parameters(conn->conn_ops, conn->param_list);
	/*
	 * SCSI Initiator -> SCSI Target Port Mapping
	 */
	if (!zero_tsih) {
		iscsi_set_session_parameters(sess->sess_ops,
				conn->param_list, 0);
		iscsi_release_param_list(conn->param_list);
		conn->param_list = NULL;

		spin_lock_bh(&sess->conn_lock);
		atomic_set(&sess->session_continuation, 0);
		if (sess->session_state == TARG_SESS_STATE_FAILED) {
			pr_debug("Moving to"
					" TARG_SESS_STATE_LOGGED_IN.\n");
			sess->session_state = TARG_SESS_STATE_LOGGED_IN;
			stop_timer = 1;
		}

		pr_debug("iSCSI Login successful on CID: %hu from %pISpc to"
			" %pISpc,%hu\n", conn->cid, &conn->login_sockaddr,
			&conn->local_sockaddr, tpg->tpgt);

		list_add_tail(&conn->conn_list, &sess->sess_conn_list);
		atomic_inc(&sess->nconn);
		pr_debug("Incremented iSCSI Connection count to %hu"
			" from node: %s\n", atomic_read(&sess->nconn),
			sess->sess_ops->InitiatorName);
		spin_unlock_bh(&sess->conn_lock);

		iscsi_post_login_start_timers(conn);
		/*
		 * Determine CPU mask to ensure connection's RX and TX kthreads
		 * are scheduled on the same CPU.
		 */
		iscsit_thread_get_cpumask(conn);
		conn->conn_rx_reset_cpumask = 1;
		conn->conn_tx_reset_cpumask = 1;
		/*
		 * Wakeup the sleeping iscsi_target_rx_thread() now that
		 * iscsi_conn is in TARG_CONN_STATE_LOGGED_IN state.
		 */
		complete(&conn->rx_login_comp);
		iscsit_dec_conn_usage_count(conn);

		if (stop_timer) {
			spin_lock_bh(&se_tpg->session_lock);
			iscsit_stop_time2retain_timer(sess);
			spin_unlock_bh(&se_tpg->session_lock);
		}
		iscsit_dec_session_usage_count(sess);
		return;
	}

	iscsi_set_session_parameters(sess->sess_ops, conn->param_list, 1);
	iscsi_release_param_list(conn->param_list);
	conn->param_list = NULL;

	iscsit_determine_maxcmdsn(sess);

	spin_lock_bh(&se_tpg->session_lock);
	__transport_register_session(&sess->tpg->tpg_se_tpg,
			se_sess->se_node_acl, se_sess, sess);
	pr_debug("Moving to TARG_SESS_STATE_LOGGED_IN.\n");
	sess->session_state = TARG_SESS_STATE_LOGGED_IN;

	pr_debug("iSCSI Login successful on CID: %hu from %pISpc to %pISpc,%hu\n",
		conn->cid, &conn->login_sockaddr, &conn->local_sockaddr,
		tpg->tpgt);

	spin_lock_bh(&sess->conn_lock);
	list_add_tail(&conn->conn_list, &sess->sess_conn_list);
	atomic_inc(&sess->nconn);
	pr_debug("Incremented iSCSI Connection count to %hu from node:"
		" %s\n", atomic_read(&sess->nconn),
		sess->sess_ops->InitiatorName);
	spin_unlock_bh(&sess->conn_lock);

	sess->sid = tpg->sid++;
	if (!sess->sid)
		sess->sid = tpg->sid++;
	pr_debug("Established iSCSI session from node: %s\n",
			sess->sess_ops->InitiatorName);

	tpg->nsessions++;
	if (tpg->tpg_tiqn)
		tpg->tpg_tiqn->tiqn_nsessions++;

	pr_debug("Incremented number of active iSCSI sessions to %u on"
		" iSCSI Target Portal Group: %hu\n", tpg->nsessions, tpg->tpgt);
	spin_unlock_bh(&se_tpg->session_lock);

	iscsi_post_login_start_timers(conn);
	/*
	 * Determine CPU mask to ensure connection's RX and TX kthreads
	 * are scheduled on the same CPU.
	 */
	iscsit_thread_get_cpumask(conn);
	conn->conn_rx_reset_cpumask = 1;
	conn->conn_tx_reset_cpumask = 1;
	/*
	 * Wakeup the sleeping iscsi_target_rx_thread() now that
	 * iscsi_conn is in TARG_CONN_STATE_LOGGED_IN state.
	 */
	complete(&conn->rx_login_comp);
	iscsit_dec_conn_usage_count(conn);
}

static void iscsi_handle_login_thread_timeout(unsigned long data)
{
	struct iscsi_np *np = (struct iscsi_np *) data;

	spin_lock_bh(&np->np_thread_lock);
	pr_err("iSCSI Login timeout on Network Portal %pISpc\n",
			&np->np_sockaddr);

	if (np->np_login_timer_flags & ISCSI_TF_STOP) {
		spin_unlock_bh(&np->np_thread_lock);
		return;
	}

	if (np->np_thread)
		send_sig(SIGINT, np->np_thread, 1);

	np->np_login_timer_flags &= ~ISCSI_TF_RUNNING;
	spin_unlock_bh(&np->np_thread_lock);
}

static void iscsi_start_login_thread_timer(struct iscsi_np *np)
{
	/*
	 * This used the TA_LOGIN_TIMEOUT constant because at this
	 * point we do not have access to ISCSI_TPG_ATTRIB(tpg)->login_timeout
	 */
	spin_lock_bh(&np->np_thread_lock);
	init_timer(&np->np_login_timer);
	np->np_login_timer.expires = (get_jiffies_64() + TA_LOGIN_TIMEOUT * HZ);
	np->np_login_timer.data = (unsigned long)np;
	np->np_login_timer.function = iscsi_handle_login_thread_timeout;
	np->np_login_timer_flags &= ~ISCSI_TF_STOP;
	np->np_login_timer_flags |= ISCSI_TF_RUNNING;
	add_timer(&np->np_login_timer);

	pr_debug("Added timeout timer to iSCSI login request for"
			" %u seconds.\n", TA_LOGIN_TIMEOUT);
	spin_unlock_bh(&np->np_thread_lock);
}

static void iscsi_stop_login_thread_timer(struct iscsi_np *np)
{
	spin_lock_bh(&np->np_thread_lock);
	if (!(np->np_login_timer_flags & ISCSI_TF_RUNNING)) {
		spin_unlock_bh(&np->np_thread_lock);
		return;
	}
	np->np_login_timer_flags |= ISCSI_TF_STOP;
	spin_unlock_bh(&np->np_thread_lock);

	del_timer_sync(&np->np_login_timer);

	spin_lock_bh(&np->np_thread_lock);
	np->np_login_timer_flags &= ~ISCSI_TF_RUNNING;
	spin_unlock_bh(&np->np_thread_lock);
}

int iscsit_setup_np(
	struct iscsi_np *np,
	struct sockaddr_storage *sockaddr)
{
	struct socket *sock = NULL;
	int backlog = ISCSIT_TCP_BACKLOG, ret, opt = 0, len;

	switch (np->np_network_transport) {
	case ISCSI_TCP:
		np->np_ip_proto = IPPROTO_TCP;
		np->np_sock_type = SOCK_STREAM;
		break;
	case ISCSI_SCTP_TCP:
		np->np_ip_proto = IPPROTO_SCTP;
		np->np_sock_type = SOCK_STREAM;
		break;
	case ISCSI_SCTP_UDP:
		np->np_ip_proto = IPPROTO_SCTP;
		np->np_sock_type = SOCK_SEQPACKET;
		break;
	default:
		pr_err("Unsupported network_transport: %d\n",
				np->np_network_transport);
		return -EINVAL;
	}

	np->np_ip_proto = IPPROTO_TCP;
	np->np_sock_type = SOCK_STREAM;

	ret = sock_create(sockaddr->ss_family, np->np_sock_type,
			np->np_ip_proto, &sock);
	if (ret < 0) {
		pr_err("sock_create() failed.\n");
		return ret;
	}
	np->np_socket = sock;
	/*
	 * Setup the np->np_sockaddr from the passed sockaddr setup
	 * in iscsi_target_configfs.c code..
	 */
	memcpy(&np->np_sockaddr, sockaddr,
			sizeof(struct sockaddr_storage));

	if (sockaddr->ss_family == AF_INET6)
		len = sizeof(struct sockaddr_in6);
	else
		len = sizeof(struct sockaddr_in);
	/*
	 * Set SO_REUSEADDR, and disable Nagel Algorithm with TCP_NODELAY.
	 */
	/* FIXME: Someone please explain why this is endian-safe */
	opt = 1;
	if (np->np_network_transport == ISCSI_TCP) {
		ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,
				(char *)&opt, sizeof(opt));
		if (ret < 0) {
			pr_err("kernel_setsockopt() for TCP_NODELAY"
				" failed: %d\n", ret);
			goto fail;
		}
	}

	/* FIXME: Someone please explain why this is endian-safe */
	ret = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
			(char *)&opt, sizeof(opt));
	if (ret < 0) {
		pr_err("kernel_setsockopt() for SO_REUSEADDR"
			" failed\n");
		goto fail;
	}

	ret = kernel_setsockopt(sock, IPPROTO_IP, IP_FREEBIND,
			(char *)&opt, sizeof(opt));
	if (ret < 0) {
		pr_err("kernel_setsockopt() for IP_FREEBIND"
			" failed\n");
		goto fail;
	}

	ret = kernel_bind(sock, (struct sockaddr *)&np->np_sockaddr, len);
	if (ret < 0) {
		pr_err("kernel_bind() failed: %d\n", ret);
		goto fail;
	}

	ret = kernel_listen(sock, backlog);
	if (ret != 0) {
		pr_err("kernel_listen() failed: %d\n", ret);
		goto fail;
	}

	return 0;
fail:
	np->np_socket = NULL;
	sock_release(sock);
	return ret;
}

int iscsi_target_setup_login_socket(
	struct iscsi_np *np,
	struct sockaddr_storage *sockaddr)
{
	struct iscsit_transport *t;
	int rc;

	t = iscsit_get_transport(np->np_network_transport);
	if (!t)
		return -EINVAL;

	rc = t->iscsit_setup_np(np, sockaddr);
	if (rc < 0) {
		iscsit_put_transport(t);
		return rc;
	}

	np->np_transport = t;
	np->enabled = true;
	return 0;
}

int iscsit_accept_np(struct iscsi_np *np, struct iscsi_conn *conn)
{
	struct socket *new_sock, *sock = np->np_socket;
	struct sockaddr_in sock_in;
	struct sockaddr_in6 sock_in6;
	int rc, err;

	rc = kernel_accept(sock, &new_sock, 0);
	if (rc < 0)
		return rc;

	conn->sock = new_sock;
	conn->login_family = np->np_sockaddr.ss_family;

	if (np->np_sockaddr.ss_family == AF_INET6) {
		memset(&sock_in6, 0, sizeof(struct sockaddr_in6));

		rc = conn->sock->ops->getname(conn->sock,
				(struct sockaddr *)&sock_in6, &err, 1);
		if (!rc) {
			if (!ipv6_addr_v4mapped(&sock_in6.sin6_addr)) {
				memcpy(&conn->login_sockaddr, &sock_in6, sizeof(sock_in6));
			} else {
				/* Pretend to be an ipv4 socket */
				sock_in.sin_family = AF_INET;
				sock_in.sin_port = sock_in6.sin6_port;
				memcpy(&sock_in.sin_addr, &sock_in6.sin6_addr.s6_addr32[3], 4);
				memcpy(&conn->login_sockaddr, &sock_in, sizeof(sock_in));
			}
		}

		rc = conn->sock->ops->getname(conn->sock,
				(struct sockaddr *)&sock_in6, &err, 0);
		if (!rc) {
			if (!ipv6_addr_v4mapped(&sock_in6.sin6_addr)) {
				memcpy(&conn->local_sockaddr, &sock_in6, sizeof(sock_in6));
			} else {
				/* Pretend to be an ipv4 socket */
				sock_in.sin_family = AF_INET;
				sock_in.sin_port = sock_in6.sin6_port;
				memcpy(&sock_in.sin_addr, &sock_in6.sin6_addr.s6_addr32[3], 4);
				memcpy(&conn->local_sockaddr, &sock_in, sizeof(sock_in));
			}
		}
	} else {
		memset(&sock_in, 0, sizeof(struct sockaddr_in));

		rc = conn->sock->ops->getname(conn->sock,
				(struct sockaddr *)&sock_in, &err, 1);
		if (!rc)
			memcpy(&conn->login_sockaddr, &sock_in, sizeof(sock_in));

		rc = conn->sock->ops->getname(conn->sock,
				(struct sockaddr *)&sock_in, &err, 0);
		if (!rc)
			memcpy(&conn->local_sockaddr, &sock_in, sizeof(sock_in));
	}

	return 0;
}

int iscsit_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
{
	struct iscsi_login_req *login_req;
	u32 padding = 0, payload_length;

	if (iscsi_login_rx_data(conn, login->req, ISCSI_HDR_LEN) < 0)
		return -1;

	login_req = (struct iscsi_login_req *)login->req;
	payload_length	= ntoh24(login_req->dlength);
	padding = ((-payload_length) & 3);

	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, CID: %hu, Length: %u\n",
		login_req->flags, login_req->itt, login_req->cmdsn,
		login_req->exp_statsn, login_req->cid, payload_length);
	/*
	 * Setup the initial iscsi_login values from the leading
	 * login request PDU.
	 */
	if (login->first_request) {
		login_req = (struct iscsi_login_req *)login->req;
		login->leading_connection = (!login_req->tsih) ? 1 : 0;
		login->current_stage	= ISCSI_LOGIN_CURRENT_STAGE(login_req->flags);
		login->version_min	= login_req->min_version;
		login->version_max	= login_req->max_version;
		memcpy(login->isid, login_req->isid, 6);
		login->cmd_sn		= be32_to_cpu(login_req->cmdsn);
		login->init_task_tag	= login_req->itt;
		login->initial_exp_statsn = be32_to_cpu(login_req->exp_statsn);
		login->cid		= be16_to_cpu(login_req->cid);
		login->tsih		= be16_to_cpu(login_req->tsih);
	}

	if (iscsi_target_check_login_request(conn, login) < 0)
		return -1;

	memset(login->req_buf, 0, MAX_KEY_VALUE_PAIRS);
	if (iscsi_login_rx_data(conn, login->req_buf,
				payload_length + padding) < 0)
		return -1;

	return 0;
}

int iscsit_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
			u32 length)
{
	if (iscsi_login_tx_data(conn, login->rsp, login->rsp_buf, length) < 0)
		return -1;

	return 0;
}

static int
iscsit_conn_set_transport(struct iscsi_conn *conn, struct iscsit_transport *t)
{
	int rc;

	if (!t->owner) {
		conn->conn_transport = t;
		return 0;
	}

	rc = try_module_get(t->owner);
	if (!rc) {
		pr_err("try_module_get() failed for %s\n", t->name);
		return -EINVAL;
	}

	conn->conn_transport = t;
	return 0;
}

void iscsi_target_login_sess_out(struct iscsi_conn *conn,
		struct iscsi_np *np, bool zero_tsih, bool new_sess)
{
	if (!new_sess)
		goto old_sess_out;

	pr_err("iSCSI Login negotiation failed.\n");
	iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
				   ISCSI_LOGIN_STATUS_INIT_ERR);
	if (!zero_tsih || !conn->sess)
		goto old_sess_out;
	if (conn->sess->se_sess)
		transport_free_session(conn->sess->se_sess);
	if (conn->sess->session_index != 0) {
		spin_lock_bh(&sess_idr_lock);
		idr_remove(&sess_idr, conn->sess->session_index);
		spin_unlock_bh(&sess_idr_lock);
	}
	kfree(conn->sess->sess_ops);
	kfree(conn->sess);
	conn->sess = NULL;

old_sess_out:
	iscsi_stop_login_thread_timer(np);
	/*
	 * If login negotiation fails check if the Time2Retain timer
	 * needs to be restarted.
	 */
	if (!zero_tsih && conn->sess) {
		spin_lock_bh(&conn->sess->conn_lock);
		if (conn->sess->session_state == TARG_SESS_STATE_FAILED) {
			struct se_portal_group *se_tpg =
					&conn->tpg->tpg_se_tpg;

			atomic_set(&conn->sess->session_continuation, 0);
			spin_unlock_bh(&conn->sess->conn_lock);
			spin_lock_bh(&se_tpg->session_lock);
			iscsit_start_time2retain_handler(conn->sess);
			spin_unlock_bh(&se_tpg->session_lock);
		} else
			spin_unlock_bh(&conn->sess->conn_lock);
		iscsit_dec_session_usage_count(conn->sess);
	}

	ahash_request_free(conn->conn_tx_hash);
	if (conn->conn_rx_hash) {
		struct crypto_ahash *tfm;

		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
		ahash_request_free(conn->conn_rx_hash);
		crypto_free_ahash(tfm);
	}

	free_cpumask_var(conn->conn_cpumask);

	kfree(conn->conn_ops);

	if (conn->param_list) {
		iscsi_release_param_list(conn->param_list);
		conn->param_list = NULL;
	}
	iscsi_target_nego_release(conn);

	if (conn->sock) {
		sock_release(conn->sock);
		conn->sock = NULL;
	}

	if (conn->conn_transport->iscsit_wait_conn)
		conn->conn_transport->iscsit_wait_conn(conn);

	if (conn->conn_transport->iscsit_free_conn)
		conn->conn_transport->iscsit_free_conn(conn);

	iscsit_put_transport(conn->conn_transport);
	kfree(conn);
}

static int __iscsi_target_login_thread(struct iscsi_np *np)
{
	u8 *buffer, zero_tsih = 0;
	int ret = 0, rc;
	struct iscsi_conn *conn = NULL;
	struct iscsi_login *login;
	struct iscsi_portal_group *tpg = NULL;
	struct iscsi_login_req *pdu;
	struct iscsi_tpg_np *tpg_np;
	bool new_sess = false;

	flush_signals(current);

	spin_lock_bh(&np->np_thread_lock);
	if (np->np_thread_state == ISCSI_NP_THREAD_RESET) {
		np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
		complete(&np->np_restart_comp);
	} else if (np->np_thread_state == ISCSI_NP_THREAD_SHUTDOWN) {
		spin_unlock_bh(&np->np_thread_lock);
		goto exit;
	} else {
		np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
	}
	spin_unlock_bh(&np->np_thread_lock);

	conn = kzalloc(sizeof(struct iscsi_conn), GFP_KERNEL);
	if (!conn) {
		pr_err("Could not allocate memory for"
			" new connection\n");
		/* Get another socket */
		return 1;
	}
	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
	conn->conn_state = TARG_CONN_STATE_FREE;

	if (iscsit_conn_set_transport(conn, np->np_transport) < 0) {
		kfree(conn);
		return 1;
	}

	rc = np->np_transport->iscsit_accept_np(np, conn);
	if (rc == -ENOSYS) {
		complete(&np->np_restart_comp);
		iscsit_put_transport(conn->conn_transport);
		kfree(conn);
		conn = NULL;
		goto exit;
	} else if (rc < 0) {
		spin_lock_bh(&np->np_thread_lock);
		if (np->np_thread_state == ISCSI_NP_THREAD_RESET) {
			spin_unlock_bh(&np->np_thread_lock);
			complete(&np->np_restart_comp);
			iscsit_put_transport(conn->conn_transport);
			kfree(conn);
			conn = NULL;
			/* Get another socket */
			return 1;
		}
		spin_unlock_bh(&np->np_thread_lock);
		iscsit_put_transport(conn->conn_transport);
		kfree(conn);
		conn = NULL;
		goto out;
	}
	/*
	 * Perform the remaining iSCSI connection initialization items..
	 */
	login = iscsi_login_init_conn(conn);
	if (!login) {
		goto new_sess_out;
	}

	iscsi_start_login_thread_timer(np);

	pr_debug("Moving to TARG_CONN_STATE_XPT_UP.\n");
	conn->conn_state = TARG_CONN_STATE_XPT_UP;
	/*
	 * This will process the first login request + payload..
	 */
	rc = np->np_transport->iscsit_get_login_rx(conn, login);
	if (rc == 1)
		return 1;
	else if (rc < 0)
		goto new_sess_out;

	buffer = &login->req[0];
	pdu = (struct iscsi_login_req *)buffer;
	/*
	 * Used by iscsit_tx_login_rsp() for Login Resonses PDUs
	 * when Status-Class != 0.
	*/
	conn->login_itt	= pdu->itt;

	spin_lock_bh(&np->np_thread_lock);
	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
		spin_unlock_bh(&np->np_thread_lock);
		pr_err("iSCSI Network Portal on %pISpc currently not"
			" active.\n", &np->np_sockaddr);
		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
		goto new_sess_out;
	}
	spin_unlock_bh(&np->np_thread_lock);

	conn->network_transport = np->np_network_transport;

	pr_debug("Received iSCSI login request from %pISpc on %s Network"
		" Portal %pISpc\n", &conn->login_sockaddr, np->np_transport->name,
		&conn->local_sockaddr);

	pr_debug("Moving to TARG_CONN_STATE_IN_LOGIN.\n");
	conn->conn_state	= TARG_CONN_STATE_IN_LOGIN;

	if (iscsi_login_check_initiator_version(conn, pdu->max_version,
			pdu->min_version) < 0)
		goto new_sess_out;

	zero_tsih = (pdu->tsih == 0x0000);
	if (zero_tsih) {
		/*
		 * This is the leading connection of a new session.
		 * We wait until after authentication to check for
		 * session reinstatement.
		 */
		if (iscsi_login_zero_tsih_s1(conn, buffer) < 0)
			goto new_sess_out;
	} else {
		/*
		 * Add a new connection to an existing session.
		 * We check for a non-existant session in
		 * iscsi_login_non_zero_tsih_s2() below based
		 * on ISID/TSIH, but wait until after authentication
		 * to check for connection reinstatement, etc.
		 */
		if (iscsi_login_non_zero_tsih_s1(conn, buffer) < 0)
			goto new_sess_out;
	}
	/*
	 * SessionType: Discovery
	 *
	 * 	Locates Default Portal
	 *
	 * SessionType: Normal
	 *
	 * 	Locates Target Portal from NP -> Target IQN
	 */
	rc = iscsi_target_locate_portal(np, conn, login);
	if (rc < 0) {
		tpg = conn->tpg;
		goto new_sess_out;
	}
	login->zero_tsih = zero_tsih;

	if (conn->sess)
		conn->sess->se_sess->sup_prot_ops =
			conn->conn_transport->iscsit_get_sup_prot_ops(conn);

	tpg = conn->tpg;
	if (!tpg) {
		pr_err("Unable to locate struct iscsi_conn->tpg\n");
		goto new_sess_out;
	}

	if (zero_tsih) {
		if (iscsi_login_zero_tsih_s2(conn) < 0)
			goto new_sess_out;
	} else {
		if (iscsi_login_non_zero_tsih_s2(conn, buffer) < 0)
			goto old_sess_out;
	}

	if (conn->conn_transport->iscsit_validate_params) {
		ret = conn->conn_transport->iscsit_validate_params(conn);
		if (ret < 0) {
			if (zero_tsih)
				goto new_sess_out;
			else
				goto old_sess_out;
		}
	}

	ret = iscsi_target_start_negotiation(login, conn);
	if (ret < 0)
		goto new_sess_out;

	iscsi_stop_login_thread_timer(np);

	if (ret == 1) {
		tpg_np = conn->tpg_np;

		iscsi_post_login_handler(np, conn, zero_tsih);
		iscsit_deaccess_np(np, tpg, tpg_np);
	}

	tpg = NULL;
	tpg_np = NULL;
	/* Get another socket */
	return 1;

new_sess_out:
	new_sess = true;
old_sess_out:
	tpg_np = conn->tpg_np;
	iscsi_target_login_sess_out(conn, np, zero_tsih, new_sess);
	new_sess = false;

	if (tpg) {
		iscsit_deaccess_np(np, tpg, tpg_np);
		tpg = NULL;
		tpg_np = NULL;
	}

out:
	return 1;

exit:
	iscsi_stop_login_thread_timer(np);
	spin_lock_bh(&np->np_thread_lock);
	np->np_thread_state = ISCSI_NP_THREAD_EXIT;
	spin_unlock_bh(&np->np_thread_lock);

	return 0;
}

int iscsi_target_login_thread(void *arg)
{
	struct iscsi_np *np = arg;
	int ret;

	allow_signal(SIGINT);

	while (1) {
		ret = __iscsi_target_login_thread(np);
		/*
		 * We break and exit here unless another sock_accept() call
		 * is expected.
		 */
		if (ret != 1)
			break;
	}

	return 0;
}