iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

1 files changed, 1067 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
new file mode 100644
index 000000000000..713a4d23557a
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -0,0 +1,1067 @@
+/*******************************************************************************
+ * This file contains main functions related to iSCSI Parameter negotiation.
+ *
+ * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
+ *
+ * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
+ *
+ * Author: 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.
+ ******************************************************************************/
+
+#include <linux/ctype.h>
+#include <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_tpg.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_parameters.h"
+#include "iscsi_target_login.h"
+#include "iscsi_target_nego.h"
+#include "iscsi_target_tpg.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target.h"
+#include "iscsi_target_auth.h"
+
+#define MAX_LOGIN_PDUS  7
+#define TEXT_LEN	4096
+
+void convert_null_to_semi(char *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		if (buf[i] == '\0')
+			buf[i] = ';';
+}
+
+int strlen_semi(char *buf)
+{
+	int i = 0;
+
+	while (buf[i] != '\0') {
+		if (buf[i] == ';')
+			return i;
+		i++;
+	}
+
+	return -1;
+}
+
+int extract_param(
+	const char *in_buf,
+	const char *pattern,
+	unsigned int max_length,
+	char *out_buf,
+	unsigned char *type)
+{
+	char *ptr;
+	int len;
+
+	if (!in_buf || !pattern || !out_buf || !type)
+		return -1;
+
+	ptr = strstr(in_buf, pattern);
+	if (!ptr)
+		return -1;
+
+	ptr = strstr(ptr, "=");
+	if (!ptr)
+		return -1;
+
+	ptr += 1;
+	if (*ptr == '0' && (*(ptr+1) == 'x' || *(ptr+1) == 'X')) {
+		ptr += 2; /* skip 0x */
+		*type = HEX;
+	} else
+		*type = DECIMAL;
+
+	len = strlen_semi(ptr);
+	if (len < 0)
+		return -1;
+
+	if (len > max_length) {
+		pr_err("Length of input: %d exeeds max_length:"
+			" %d\n", len, max_length);
+		return -1;
+	}
+	memcpy(out_buf, ptr, len);
+	out_buf[len] = '\0';
+
+	return 0;
+}
+
+static u32 iscsi_handle_authentication(
+	struct iscsi_conn *conn,
+	char *in_buf,
+	char *out_buf,
+	int in_length,
+	int *out_length,
+	unsigned char *authtype)
+{
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_auth *auth;
+	struct iscsi_node_acl *iscsi_nacl;
+	struct se_node_acl *se_nacl;
+
+	if (!sess->sess_ops->SessionType) {
+		/*
+		 * For SessionType=Normal
+		 */
+		se_nacl = conn->sess->se_sess->se_node_acl;
+		if (!se_nacl) {
+			pr_err("Unable to locate struct se_node_acl for"
+					" CHAP auth\n");
+			return -1;
+		}
+		iscsi_nacl = container_of(se_nacl, struct iscsi_node_acl,
+				se_node_acl);
+		if (!iscsi_nacl) {
+			pr_err("Unable to locate struct iscsi_node_acl for"
+					" CHAP auth\n");
+			return -1;
+		}
+
+		auth = ISCSI_NODE_AUTH(iscsi_nacl);
+	} else {
+		/*
+		 * For SessionType=Discovery
+		 */
+		auth = &iscsit_global->discovery_acl.node_auth;
+	}
+
+	if (strstr("CHAP", authtype))
+		strcpy(conn->sess->auth_type, "CHAP");
+	else
+		strcpy(conn->sess->auth_type, NONE);
+
+	if (strstr("None", authtype))
+		return 1;
+#ifdef CANSRP
+	else if (strstr("SRP", authtype))
+		return srp_main_loop(conn, auth, in_buf, out_buf,
+				&in_length, out_length);
+#endif
+	else if (strstr("CHAP", authtype))
+		return chap_main_loop(conn, auth, in_buf, out_buf,
+				&in_length, out_length);
+	else if (strstr("SPKM1", authtype))
+		return 2;
+	else if (strstr("SPKM2", authtype))
+		return 2;
+	else if (strstr("KRB5", authtype))
+		return 2;
+	else
+		return 2;
+}
+
+static void iscsi_remove_failed_auth_entry(struct iscsi_conn *conn)
+{
+	kfree(conn->auth_protocol);
+}
+
+static int iscsi_target_check_login_request(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	int req_csg, req_nsg, rsp_csg, rsp_nsg;
+	u32 payload_length;
+	struct iscsi_login_req *login_req;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+	payload_length = ntoh24(login_req->dlength);
+
+	switch (login_req->opcode & ISCSI_OPCODE_MASK) {
+	case ISCSI_OP_LOGIN:
+		break;
+	default:
+		pr_err("Received unknown opcode 0x%02x.\n",
+				login_req->opcode & ISCSI_OPCODE_MASK);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if ((login_req->flags & ISCSI_FLAG_LOGIN_CONTINUE) &&
+	    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
+		pr_err("Login request has both ISCSI_FLAG_LOGIN_CONTINUE"
+			" and ISCSI_FLAG_LOGIN_TRANSIT set, protocol error.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	req_csg = (login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
+	rsp_csg = (login_rsp->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
+	req_nsg = (login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK);
+	rsp_nsg = (login_rsp->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK);
+
+	if (req_csg != login->current_stage) {
+		pr_err("Initiator unexpectedly changed login stage"
+			" from %d to %d, login failed.\n", login->current_stage,
+			req_csg);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if ((req_nsg == 2) || (req_csg >= 2) ||
+	   ((login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT) &&
+	    (req_nsg <= req_csg))) {
+		pr_err("Illegal login_req->flags Combination, CSG: %d,"
+			" NSG: %d, ISCSI_FLAG_LOGIN_TRANSIT: %d.\n", req_csg,
+			req_nsg, (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT));
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if ((login_req->max_version != login->version_max) ||
+	    (login_req->min_version != login->version_min)) {
+		pr_err("Login request changed Version Max/Nin"
+			" unexpectedly to 0x%02x/0x%02x, protocol error\n",
+			login_req->max_version, login_req->min_version);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if (memcmp(login_req->isid, login->isid, 6) != 0) {
+		pr_err("Login request changed ISID unexpectedly,"
+				" protocol error.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if (login_req->itt != login->init_task_tag) {
+		pr_err("Login request changed ITT unexpectedly to"
+			" 0x%08x, protocol error.\n", login_req->itt);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_INIT_ERR);
+		return -1;
+	}
+
+	if (payload_length > MAX_KEY_VALUE_PAIRS) {
+		pr_err("Login request payload exceeds default"
+			" MaxRecvDataSegmentLength: %u, protocol error.\n",
+				MAX_KEY_VALUE_PAIRS);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int iscsi_target_check_first_request(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	struct iscsi_param *param = NULL;
+	struct se_node_acl *se_nacl;
+
+	login->first_request = 0;
+
+	list_for_each_entry(param, &conn->param_list->param_list, p_list) {
+		if (!strncmp(param->name, SESSIONTYPE, 11)) {
+			if (!IS_PSTATE_ACCEPTOR(param)) {
+				pr_err("SessionType key not received"
+					" in first login request.\n");
+				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
+				return -1;
+			}
+			if (!strncmp(param->value, DISCOVERY, 9))
+				return 0;
+		}
+
+		if (!strncmp(param->name, INITIATORNAME, 13)) {
+			if (!IS_PSTATE_ACCEPTOR(param)) {
+				if (!login->leading_connection)
+					continue;
+
+				pr_err("InitiatorName key not received"
+					" in first login request.\n");
+				iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+					ISCSI_LOGIN_STATUS_MISSING_FIELDS);
+				return -1;
+			}
+
+			/*
+			 * For non-leading connections, double check that the
+			 * received InitiatorName matches the existing session's
+			 * struct iscsi_node_acl.
+			 */
+			if (!login->leading_connection) {
+				se_nacl = conn->sess->se_sess->se_node_acl;
+				if (!se_nacl) {
+					pr_err("Unable to locate"
+						" struct se_node_acl\n");
+					iscsit_tx_login_rsp(conn,
+							ISCSI_STATUS_CLS_INITIATOR_ERR,
+							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
+					return -1;
+				}
+
+				if (strcmp(param->value,
+						se_nacl->initiatorname)) {
+					pr_err("Incorrect"
+						" InitiatorName: %s for this"
+						" iSCSI Initiator Node.\n",
+						param->value);
+					iscsit_tx_login_rsp(conn,
+							ISCSI_STATUS_CLS_INITIATOR_ERR,
+							ISCSI_LOGIN_STATUS_TGT_NOT_FOUND);
+					return -1;
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	u32 padding = 0;
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+
+	login_rsp->opcode		= ISCSI_OP_LOGIN_RSP;
+	hton24(login_rsp->dlength, login->rsp_length);
+	memcpy(login_rsp->isid, login->isid, 6);
+	login_rsp->tsih			= cpu_to_be16(login->tsih);
+	login_rsp->itt			= cpu_to_be32(login->init_task_tag);
+	login_rsp->statsn		= cpu_to_be32(conn->stat_sn++);
+	login_rsp->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
+	login_rsp->max_cmdsn		= cpu_to_be32(conn->sess->max_cmd_sn);
+
+	pr_debug("Sending Login Response, Flags: 0x%02x, ITT: 0x%08x,"
+		" ExpCmdSN; 0x%08x, MaxCmdSN: 0x%08x, StatSN: 0x%08x, Length:"
+		" %u\n", login_rsp->flags, ntohl(login_rsp->itt),
+		ntohl(login_rsp->exp_cmdsn), ntohl(login_rsp->max_cmdsn),
+		ntohl(login_rsp->statsn), login->rsp_length);
+
+	padding = ((-login->rsp_length) & 3);
+
+	if (iscsi_login_tx_data(
+			conn,
+			login->rsp,
+			login->rsp_buf,
+			login->rsp_length + padding) < 0)
+		return -1;
+
+	login->rsp_length		= 0;
+	login_rsp->tsih			= be16_to_cpu(login_rsp->tsih);
+	login_rsp->itt			= be32_to_cpu(login_rsp->itt);
+	login_rsp->statsn		= be32_to_cpu(login_rsp->statsn);
+	mutex_lock(&sess->cmdsn_mutex);
+	login_rsp->exp_cmdsn		= be32_to_cpu(sess->exp_cmd_sn);
+	login_rsp->max_cmdsn		= be32_to_cpu(sess->max_cmd_sn);
+	mutex_unlock(&sess->cmdsn_mutex);
+
+	return 0;
+}
+
+static int iscsi_target_do_rx_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	u32 padding = 0, payload_length;
+	struct iscsi_login_req *login_req;
+
+	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);
+	login_req->tsih			= be16_to_cpu(login_req->tsih);
+	login_req->itt			= be32_to_cpu(login_req->itt);
+	login_req->cid			= be16_to_cpu(login_req->cid);
+	login_req->cmdsn		= be32_to_cpu(login_req->cmdsn);
+	login_req->exp_statsn		= be32_to_cpu(login_req->exp_statsn);
+
+	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);
+
+	if (iscsi_target_check_login_request(conn, login) < 0)
+		return -1;
+
+	padding = ((-payload_length) & 3);
+	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;
+}
+
+static int iscsi_target_do_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	if (iscsi_target_do_tx_login_io(conn, login) < 0)
+		return -1;
+
+	if (iscsi_target_do_rx_login_io(conn, login) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int iscsi_target_get_initial_payload(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	u32 padding = 0, payload_length;
+	struct iscsi_login_req *login_req;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	payload_length = ntoh24(login_req->dlength);
+
+	pr_debug("Got Login Command, Flags 0x%02x, ITT: 0x%08x,"
+		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
+		login_req->flags, login_req->itt, login_req->cmdsn,
+		login_req->exp_statsn, payload_length);
+
+	if (iscsi_target_check_login_request(conn, login) < 0)
+		return -1;
+
+	padding = ((-payload_length) & 3);
+
+	if (iscsi_login_rx_data(
+			conn,
+			login->req_buf,
+			payload_length + padding) < 0)
+		return -1;
+
+	return 0;
+}
+
+/*
+ *	NOTE: We check for existing sessions or connections AFTER the initiator
+ *	has been successfully authenticated in order to protect against faked
+ *	ISID/TSIH combinations.
+ */
+static int iscsi_target_check_for_existing_instances(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	if (login->checked_for_existing)
+		return 0;
+
+	login->checked_for_existing = 1;
+
+	if (!login->tsih)
+		return iscsi_check_for_session_reinstatement(conn);
+	else
+		return iscsi_login_post_auth_non_zero_tsih(conn, login->cid,
+				login->initial_exp_statsn);
+}
+
+static int iscsi_target_do_authentication(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	int authret;
+	u32 payload_length;
+	struct iscsi_param *param;
+	struct iscsi_login_req *login_req;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+	payload_length = ntoh24(login_req->dlength);
+
+	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
+	if (!param)
+		return -1;
+
+	authret = iscsi_handle_authentication(
+			conn,
+			login->req_buf,
+			login->rsp_buf,
+			payload_length,
+			&login->rsp_length,
+			param->value);
+	switch (authret) {
+	case 0:
+		pr_debug("Received OK response"
+		" from LIO Authentication, continuing.\n");
+		break;
+	case 1:
+		pr_debug("iSCSI security negotiation"
+			" completed sucessfully.\n");
+		login->auth_complete = 1;
+		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
+		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
+			login_rsp->flags |= (ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
+					     ISCSI_FLAG_LOGIN_TRANSIT);
+			login->current_stage = 1;
+		}
+		return iscsi_target_check_for_existing_instances(
+				conn, login);
+	case 2:
+		pr_err("Security negotiation"
+			" failed.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_AUTH_FAILED);
+		return -1;
+	default:
+		pr_err("Received unknown error %d from LIO"
+				" Authentication\n", authret);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_TARGET_ERROR);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int iscsi_target_handle_csg_zero(
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	int ret;
+	u32 payload_length;
+	struct iscsi_param *param;
+	struct iscsi_login_req *login_req;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+	payload_length = ntoh24(login_req->dlength);
+
+	param = iscsi_find_param_from_key(AUTHMETHOD, conn->param_list);
+	if (!param)
+		return -1;
+
+	ret = iscsi_decode_text_input(
+			PHASE_SECURITY|PHASE_DECLARATIVE,
+			SENDER_INITIATOR|SENDER_RECEIVER,
+			login->req_buf,
+			payload_length,
+			conn->param_list);
+	if (ret < 0)
+		return -1;
+
+	if (ret > 0) {
+		if (login->auth_complete) {
+			pr_err("Initiator has already been"
+				" successfully authenticated, but is still"
+				" sending %s keys.\n", param->value);
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+					ISCSI_LOGIN_STATUS_INIT_ERR);
+			return -1;
+		}
+
+		goto do_auth;
+	}
+
+	if (login->first_request)
+		if (iscsi_target_check_first_request(conn, login) < 0)
+			return -1;
+
+	ret = iscsi_encode_text_output(
+			PHASE_SECURITY|PHASE_DECLARATIVE,
+			SENDER_TARGET,
+			login->rsp_buf,
+			&login->rsp_length,
+			conn->param_list);
+	if (ret < 0)
+		return -1;
+
+	if (!iscsi_check_negotiated_keys(conn->param_list)) {
+		if (ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication &&
+		    !strncmp(param->value, NONE, 4)) {
+			pr_err("Initiator sent AuthMethod=None but"
+				" Target is enforcing iSCSI Authentication,"
+					" login failed.\n");
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+					ISCSI_LOGIN_STATUS_AUTH_FAILED);
+			return -1;
+		}
+
+		if (ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication &&
+		    !login->auth_complete)
+			return 0;
+
+		if (strncmp(param->value, NONE, 4) && !login->auth_complete)
+			return 0;
+
+		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE1) &&
+		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT)) {
+			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE1 |
+					    ISCSI_FLAG_LOGIN_TRANSIT;
+			login->current_stage = 1;
+		}
+	}
+
+	return 0;
+do_auth:
+	return iscsi_target_do_authentication(conn, login);
+}
+
+static int iscsi_target_handle_csg_one(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	int ret;
+	u32 payload_length;
+	struct iscsi_login_req *login_req;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+	payload_length = ntoh24(login_req->dlength);
+
+	ret = iscsi_decode_text_input(
+			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
+			SENDER_INITIATOR|SENDER_RECEIVER,
+			login->req_buf,
+			payload_length,
+			conn->param_list);
+	if (ret < 0)
+		return -1;
+
+	if (login->first_request)
+		if (iscsi_target_check_first_request(conn, login) < 0)
+			return -1;
+
+	if (iscsi_target_check_for_existing_instances(conn, login) < 0)
+		return -1;
+
+	ret = iscsi_encode_text_output(
+			PHASE_OPERATIONAL|PHASE_DECLARATIVE,
+			SENDER_TARGET,
+			login->rsp_buf,
+			&login->rsp_length,
+			conn->param_list);
+	if (ret < 0)
+		return -1;
+
+	if (!login->auth_complete &&
+	     ISCSI_TPG_ATTRIB(ISCSI_TPG_C(conn))->authentication) {
+		pr_err("Initiator is requesting CSG: 1, has not been"
+			 " successfully authenticated, and the Target is"
+			" enforcing iSCSI Authentication, login failed.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_AUTH_FAILED);
+		return -1;
+	}
+
+	if (!iscsi_check_negotiated_keys(conn->param_list))
+		if ((login_req->flags & ISCSI_FLAG_LOGIN_NEXT_STAGE3) &&
+		    (login_req->flags & ISCSI_FLAG_LOGIN_TRANSIT))
+			login_rsp->flags |= ISCSI_FLAG_LOGIN_NEXT_STAGE3 |
+					    ISCSI_FLAG_LOGIN_TRANSIT;
+
+	return 0;
+}
+
+static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	int pdu_count = 0;
+	struct iscsi_login_req *login_req;
+	struct iscsi_login_rsp *login_rsp;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_login_rsp *) login->rsp;
+
+	while (1) {
+		if (++pdu_count > MAX_LOGIN_PDUS) {
+			pr_err("MAX_LOGIN_PDUS count reached.\n");
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+					ISCSI_LOGIN_STATUS_TARGET_ERROR);
+			return -1;
+		}
+
+		switch ((login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2) {
+		case 0:
+			login_rsp->flags |= (0 & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK);
+			if (iscsi_target_handle_csg_zero(conn, login) < 0)
+				return -1;
+			break;
+		case 1:
+			login_rsp->flags |= ISCSI_FLAG_LOGIN_CURRENT_STAGE1;
+			if (iscsi_target_handle_csg_one(conn, login) < 0)
+				return -1;
+			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
+				login->tsih = conn->sess->tsih;
+				if (iscsi_target_do_tx_login_io(conn,
+						login) < 0)
+					return -1;
+				return 0;
+			}
+			break;
+		default:
+			pr_err("Illegal CSG: %d received from"
+				" Initiator, protocol error.\n",
+				(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK)
+				>> 2);
+			break;
+		}
+
+		if (iscsi_target_do_login_io(conn, login) < 0)
+			return -1;
+
+		if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
+			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
+			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
+		}
+	}
+
+	return 0;
+}
+
+static void iscsi_initiatorname_tolower(
+	char *param_buf)
+{
+	char *c;
+	u32 iqn_size = strlen(param_buf), i;
+
+	for (i = 0; i < iqn_size; i++) {
+		c = (char *)&param_buf[i];
+		if (!isupper(*c))
+			continue;
+
+		*c = tolower(*c);
+	}
+}
+
+/*
+ * Processes the first Login Request..
+ */
+static int iscsi_target_locate_portal(
+	struct iscsi_np *np,
+	struct iscsi_conn *conn,
+	struct iscsi_login *login)
+{
+	char *i_buf = NULL, *s_buf = NULL, *t_buf = NULL;
+	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_tiqn *tiqn;
+	struct iscsi_login_req *login_req;
+	struct iscsi_targ_login_rsp *login_rsp;
+	u32 payload_length;
+	int sessiontype = 0, ret = 0;
+
+	login_req = (struct iscsi_login_req *) login->req;
+	login_rsp = (struct iscsi_targ_login_rsp *) login->rsp;
+	payload_length = ntoh24(login_req->dlength);
+
+	login->first_request	= 1;
+	login->leading_connection = (!login_req->tsih) ? 1 : 0;
+	login->current_stage	=
+		(login_req->flags & ISCSI_FLAG_LOGIN_CURRENT_STAGE_MASK) >> 2;
+	login->version_min	= login_req->min_version;
+	login->version_max	= login_req->max_version;
+	memcpy(login->isid, login_req->isid, 6);
+	login->cmd_sn		= login_req->cmdsn;
+	login->init_task_tag	= login_req->itt;
+	login->initial_exp_statsn = login_req->exp_statsn;
+	login->cid		= login_req->cid;
+	login->tsih		= login_req->tsih;
+
+	if (iscsi_target_get_initial_payload(conn, login) < 0)
+		return -1;
+
+	tmpbuf = kzalloc(payload_length + 1, GFP_KERNEL);
+	if (!tmpbuf) {
+		pr_err("Unable to allocate memory for tmpbuf.\n");
+		return -1;
+	}
+
+	memcpy(tmpbuf, login->req_buf, payload_length);
+	tmpbuf[payload_length] = '\0';
+	start = tmpbuf;
+	end = (start + payload_length);
+
+	/*
+	 * Locate the initial keys expected from the Initiator node in
+	 * the first login request in order to progress with the login phase.
+	 */
+	while (start < end) {
+		if (iscsi_extract_key_value(start, &key, &value) < 0) {
+			ret = -1;
+			goto out;
+		}
+
+		if (!strncmp(key, "InitiatorName", 13))
+			i_buf = value;
+		else if (!strncmp(key, "SessionType", 11))
+			s_buf = value;
+		else if (!strncmp(key, "TargetName", 10))
+			t_buf = value;
+
+		start += strlen(key) + strlen(value) + 2;
+	}
+
+	/*
+	 * See 5.3.  Login Phase.
+	 */
+	if (!i_buf) {
+		pr_err("InitiatorName key not received"
+			" in first login request.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
+		ret = -1;
+		goto out;
+	}
+	/*
+	 * Convert the incoming InitiatorName to lowercase following
+	 * RFC-3720 3.2.6.1. section c) that says that iSCSI IQNs
+	 * are NOT case sensitive.
+	 */
+	iscsi_initiatorname_tolower(i_buf);
+
+	if (!s_buf) {
+		if (!login->leading_connection)
+			goto get_target;
+
+		pr_err("SessionType key not received"
+			" in first login request.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
+		ret = -1;
+		goto out;
+	}
+
+	/*
+	 * Use default portal group for discovery sessions.
+	 */
+	sessiontype = strncmp(s_buf, DISCOVERY, 9);
+	if (!sessiontype) {
+		conn->tpg = iscsit_global->discovery_tpg;
+		if (!login->leading_connection)
+			goto get_target;
+
+		sess->sess_ops->SessionType = 1;
+		/*
+		 * Setup crc32c modules from libcrypto
+		 */
+		if (iscsi_login_setup_crypto(conn) < 0) {
+			pr_err("iscsi_login_setup_crypto() failed\n");
+			ret = -1;
+			goto out;
+		}
+		/*
+		 * Serialize access across the discovery struct iscsi_portal_group to
+		 * process login attempt.
+		 */
+		if (iscsit_access_np(np, conn->tpg) < 0) {
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
+			ret = -1;
+			goto out;
+		}
+		ret = 0;
+		goto out;
+	}
+
+get_target:
+	if (!t_buf) {
+		pr_err("TargetName key not received"
+			" in first login request while"
+			" SessionType=Normal.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+			ISCSI_LOGIN_STATUS_MISSING_FIELDS);
+		ret = -1;
+		goto out;
+	}
+
+	/*
+	 * Locate Target IQN from Storage Node.
+	 */
+	tiqn = iscsit_get_tiqn_for_login(t_buf);
+	if (!tiqn) {
+		pr_err("Unable to locate Target IQN: %s in"
+			" Storage Node\n", t_buf);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
+		ret = -1;
+		goto out;
+	}
+	pr_debug("Located Storage Object: %s\n", tiqn->tiqn);
+
+	/*
+	 * Locate Target Portal Group from Storage Node.
+	 */
+	conn->tpg = iscsit_get_tpg_from_np(tiqn, np);
+	if (!conn->tpg) {
+		pr_err("Unable to locate Target Portal Group"
+				" on %s\n", tiqn->tiqn);
+		iscsit_put_tiqn_for_login(tiqn);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
+		ret = -1;
+		goto out;
+	}
+	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
+	/*
+	 * Setup crc32c modules from libcrypto
+	 */
+	if (iscsi_login_setup_crypto(conn) < 0) {
+		pr_err("iscsi_login_setup_crypto() failed\n");
+		ret = -1;
+		goto out;
+	}
+	/*
+	 * Serialize access across the struct iscsi_portal_group to
+	 * process login attempt.
+	 */
+	if (iscsit_access_np(np, conn->tpg) < 0) {
+		iscsit_put_tiqn_for_login(tiqn);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
+		ret = -1;
+		conn->tpg = NULL;
+		goto out;
+	}
+
+	/*
+	 * conn->sess->node_acl will be set when the referenced
+	 * struct iscsi_session is located from received ISID+TSIH in
+	 * iscsi_login_non_zero_tsih_s2().
+	 */
+	if (!login->leading_connection) {
+		ret = 0;
+		goto out;
+	}
+
+	/*
+	 * This value is required in iscsi_login_zero_tsih_s2()
+	 */
+	sess->sess_ops->SessionType = 0;
+
+	/*
+	 * Locate incoming Initiator IQN reference from Storage Node.
+	 */
+	sess->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
+			&conn->tpg->tpg_se_tpg, i_buf);
+	if (!sess->se_sess->se_node_acl) {
+		pr_err("iSCSI Initiator Node: %s is not authorized to"
+			" access iSCSI target portal group: %hu.\n",
+				i_buf, conn->tpg->tpgt);
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				ISCSI_LOGIN_STATUS_TGT_FORBIDDEN);
+		ret = -1;
+		goto out;
+	}
+
+	ret = 0;
+out:
+	kfree(tmpbuf);
+	return ret;
+}
+
+struct iscsi_login *iscsi_target_init_negotiation(
+	struct iscsi_np *np,
+	struct iscsi_conn *conn,
+	char *login_pdu)
+{
+	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");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+		goto out;
+	}
+
+	login->req = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
+	if (!login->req) {
+		pr_err("Unable to allocate memory for Login Request.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+		goto out;
+	}
+	memcpy(login->req, login_pdu, ISCSI_HDR_LEN);
+
+	login->req_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
+	if (!login->req_buf) {
+		pr_err("Unable to allocate memory for response buffer.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+		goto out;
+	}
+	/*
+	 * SessionType: Discovery
+	 *
+	 *	Locates Default Portal
+	 *
+	 * SessionType: Normal
+	 *
+	 *	Locates Target Portal from NP -> Target IQN
+	 */
+	if (iscsi_target_locate_portal(np, conn, login) < 0) {
+		pr_err("iSCSI Login negotiation failed.\n");
+		goto out;
+	}
+
+	return login;
+out:
+	kfree(login->req);
+	kfree(login->req_buf);
+	kfree(login);
+
+	return NULL;
+}
+
+int iscsi_target_start_negotiation(
+	struct iscsi_login *login,
+	struct iscsi_conn *conn)
+{
+	int ret = -1;
+
+	login->rsp = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
+	if (!login->rsp) {
+		pr_err("Unable to allocate memory for"
+				" Login Response.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+		ret = -1;
+		goto out;
+	}
+
+	login->rsp_buf = kzalloc(MAX_KEY_VALUE_PAIRS, GFP_KERNEL);
+	if (!login->rsp_buf) {
+		pr_err("Unable to allocate memory for"
+			" request buffer.\n");
+		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+				ISCSI_LOGIN_STATUS_NO_RESOURCES);
+		ret = -1;
+		goto out;
+	}
+
+	ret = iscsi_target_do_login(conn, login);
+out:
+	if (ret != 0)
+		iscsi_remove_failed_auth_entry(conn);
+
+	iscsi_target_nego_release(login, conn);
+	return ret;
+}
+
+void iscsi_target_nego_release(
+	struct iscsi_login *login,
+	struct iscsi_conn *conn)
+{
+	kfree(login->req);
+	kfree(login->rsp);
+	kfree(login->req_buf);
+	kfree(login->rsp_buf);
+	kfree(login);
+}