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>

drivers/target/Kconfig

@@ -31,5 +31,6 @@ config TCM_PSCSI
 
 source "drivers/target/loopback/Kconfig"
 source "drivers/target/tcm_fc/Kconfig"
+source "drivers/target/iscsi/Kconfig"
 
 endif

drivers/target/Makefile

@@ -24,5 +24,5 @@ obj-$(CONFIG_TCM_PSCSI)		+= target_core_pscsi.o
 
 # Fabric modules
 obj-$(CONFIG_LOOPBACK_TARGET)	+= loopback/
-
 obj-$(CONFIG_TCM_FC)		+= tcm_fc/
+obj-$(CONFIG_ISCSI_TARGET)	+= iscsi/

drivers/target/iscsi/Kconfig

@@ -0,0 +1,8 @@
+config ISCSI_TARGET
+	tristate "Linux-iSCSI.org iSCSI Target Mode Stack"
+	select CRYPTO
+	select CRYPTO_CRC32C
+	select CRYPTO_CRC32C_INTEL if X86
+	help
+	Say M here to enable the ConfigFS enabled Linux-iSCSI.org iSCSI
+	Target Mode Stack.

drivers/target/iscsi/Makefile

@@ -0,0 +1,20 @@
+iscsi_target_mod-y +=		iscsi_target_parameters.o \
+				iscsi_target_seq_pdu_list.o \
+				iscsi_target_tq.o \
+				iscsi_target_auth.o \
+				iscsi_target_datain_values.o \
+				iscsi_target_device.o \
+				iscsi_target_erl0.o \
+				iscsi_target_erl1.o \
+				iscsi_target_erl2.o \
+				iscsi_target_login.o \
+				iscsi_target_nego.o \
+				iscsi_target_nodeattrib.o \
+				iscsi_target_tmr.o \
+				iscsi_target_tpg.o \
+				iscsi_target_util.o \
+				iscsi_target.o \
+				iscsi_target_configfs.o \
+				iscsi_target_stat.o
+
+obj-$(CONFIG_ISCSI_TARGET)	+= iscsi_target_mod.o

drivers/target/iscsi/iscsi_target.h

@@ -0,0 +1,42 @@
+#ifndef ISCSI_TARGET_H
+#define ISCSI_TARGET_H
+
+extern struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *);
+extern struct iscsi_tiqn *iscsit_get_tiqn(unsigned char *, int);
+extern void iscsit_put_tiqn_for_login(struct iscsi_tiqn *);
+extern struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *);
+extern void iscsit_del_tiqn(struct iscsi_tiqn *);
+extern int iscsit_access_np(struct iscsi_np *, struct iscsi_portal_group *);
+extern int iscsit_deaccess_np(struct iscsi_np *, struct iscsi_portal_group *);
+extern struct iscsi_np *iscsit_add_np(struct __kernel_sockaddr_storage *,
+				char *, int);
+extern int iscsit_reset_np_thread(struct iscsi_np *, struct iscsi_tpg_np *,
+				struct iscsi_portal_group *);
+extern int iscsit_del_np(struct iscsi_np *);
+extern int iscsit_add_reject_from_cmd(u8, int, int, unsigned char *, struct iscsi_cmd *);
+extern int iscsit_logout_closesession(struct iscsi_cmd *, struct iscsi_conn *);
+extern int iscsit_logout_closeconnection(struct iscsi_cmd *, struct iscsi_conn *);
+extern int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *, struct iscsi_conn *);
+extern int iscsit_send_async_msg(struct iscsi_conn *, u16, u8, u8);
+extern int iscsit_send_r2t(struct iscsi_cmd *, struct iscsi_conn *);
+extern int iscsit_build_r2ts_for_cmd(struct iscsi_cmd *, struct iscsi_conn *, int);
+extern void iscsit_thread_get_cpumask(struct iscsi_conn *);
+extern int iscsi_target_tx_thread(void *);
+extern int iscsi_target_rx_thread(void *);
+extern int iscsit_close_connection(struct iscsi_conn *);
+extern int iscsit_close_session(struct iscsi_session *);
+extern void iscsit_fail_session(struct iscsi_session *);
+extern int iscsit_free_session(struct iscsi_session *);
+extern void iscsit_stop_session(struct iscsi_session *, int, int);
+extern int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *, int);
+
+extern struct iscsit_global *iscsit_global;
+extern struct target_fabric_configfs *lio_target_fabric_configfs;
+
+extern struct kmem_cache *lio_dr_cache;
+extern struct kmem_cache *lio_ooo_cache;
+extern struct kmem_cache *lio_cmd_cache;
+extern struct kmem_cache *lio_qr_cache;
+extern struct kmem_cache *lio_r2t_cache;
+
+#endif   /*** ISCSI_TARGET_H ***/

drivers/target/iscsi/iscsi_target_auth.c

@@ -0,0 +1,490 @@
+/*******************************************************************************
+ * This file houses the main functions for the iSCSI CHAP support
+ *
+ * \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/string.h>
+#include <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/scatterlist.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_nego.h"
+#include "iscsi_target_auth.h"
+
+static unsigned char chap_asciihex_to_binaryhex(unsigned char val[2])
+{
+	unsigned char result = 0;
+	/*
+	 * MSB
+	 */
+	if ((val[0] >= 'a') && (val[0] <= 'f'))
+		result = ((val[0] - 'a' + 10) & 0xf) << 4;
+	else
+		if ((val[0] >= 'A') && (val[0] <= 'F'))
+			result = ((val[0] - 'A' + 10) & 0xf) << 4;
+		else /* digit */
+			result = ((val[0] - '0') & 0xf) << 4;
+	/*
+	 * LSB
+	 */
+	if ((val[1] >= 'a') && (val[1] <= 'f'))
+		result |= ((val[1] - 'a' + 10) & 0xf);
+	else
+		if ((val[1] >= 'A') && (val[1] <= 'F'))
+			result |= ((val[1] - 'A' + 10) & 0xf);
+		else /* digit */
+			result |= ((val[1] - '0') & 0xf);
+
+	return result;
+}
+
+static int chap_string_to_hex(unsigned char *dst, unsigned char *src, int len)
+{
+	int i, j = 0;
+
+	for (i = 0; i < len; i += 2) {
+		dst[j++] = (unsigned char) chap_asciihex_to_binaryhex(&src[i]);
+	}
+
+	dst[j] = '\0';
+	return j;
+}
+
+static void chap_binaryhex_to_asciihex(char *dst, char *src, int src_len)
+{
+	int i;
+
+	for (i = 0; i < src_len; i++) {
+		sprintf(&dst[i*2], "%02x", (int) src[i] & 0xff);
+	}
+}
+
+static void chap_set_random(char *data, int length)
+{
+	long r;
+	unsigned n;
+
+	while (length > 0) {
+		get_random_bytes(&r, sizeof(long));
+		r = r ^ (r >> 8);
+		r = r ^ (r >> 4);
+		n = r & 0x7;
+
+		get_random_bytes(&r, sizeof(long));
+		r = r ^ (r >> 8);
+		r = r ^ (r >> 5);
+		n = (n << 3) | (r & 0x7);
+
+		get_random_bytes(&r, sizeof(long));
+		r = r ^ (r >> 8);
+		r = r ^ (r >> 5);
+		n = (n << 2) | (r & 0x3);
+
+		*data++ = n;
+		length--;
+	}
+}
+
+static void chap_gen_challenge(
+	struct iscsi_conn *conn,
+	int caller,
+	char *c_str,
+	unsigned int *c_len)
+{
+	unsigned char challenge_asciihex[CHAP_CHALLENGE_LENGTH * 2 + 1];
+	struct iscsi_chap *chap = (struct iscsi_chap *) conn->auth_protocol;
+
+	memset(challenge_asciihex, 0, CHAP_CHALLENGE_LENGTH * 2 + 1);
+
+	chap_set_random(chap->challenge, CHAP_CHALLENGE_LENGTH);
+	chap_binaryhex_to_asciihex(challenge_asciihex, chap->challenge,
+				CHAP_CHALLENGE_LENGTH);
+	/*
+	 * Set CHAP_C, and copy the generated challenge into c_str.
+	 */
+	*c_len += sprintf(c_str + *c_len, "CHAP_C=0x%s", challenge_asciihex);
+	*c_len += 1;
+
+	pr_debug("[%s] Sending CHAP_C=0x%s\n\n", (caller) ? "server" : "client",
+			challenge_asciihex);
+}
+
+
+static struct iscsi_chap *chap_server_open(
+	struct iscsi_conn *conn,
+	struct iscsi_node_auth *auth,
+	const char *a_str,
+	char *aic_str,
+	unsigned int *aic_len)
+{
+	struct iscsi_chap *chap;
+
+	if (!(auth->naf_flags & NAF_USERID_SET) ||
+	    !(auth->naf_flags & NAF_PASSWORD_SET)) {
+		pr_err("CHAP user or password not set for"
+				" Initiator ACL\n");
+		return NULL;
+	}
+
+	conn->auth_protocol = kzalloc(sizeof(struct iscsi_chap), GFP_KERNEL);
+	if (!conn->auth_protocol)
+		return NULL;
+
+	chap = (struct iscsi_chap *) conn->auth_protocol;
+	/*
+	 * We only support MD5 MDA presently.
+	 */
+	if (strncmp(a_str, "CHAP_A=5", 8)) {
+		pr_err("CHAP_A is not MD5.\n");
+		return NULL;
+	}
+	pr_debug("[server] Got CHAP_A=5\n");
+	/*
+	 * Send back CHAP_A set to MD5.
+	 */
+	*aic_len = sprintf(aic_str, "CHAP_A=5");
+	*aic_len += 1;
+	chap->digest_type = CHAP_DIGEST_MD5;
+	pr_debug("[server] Sending CHAP_A=%d\n", chap->digest_type);
+	/*
+	 * Set Identifier.
+	 */
+	chap->id = ISCSI_TPG_C(conn)->tpg_chap_id++;
+	*aic_len += sprintf(aic_str + *aic_len, "CHAP_I=%d", chap->id);
+	*aic_len += 1;
+	pr_debug("[server] Sending CHAP_I=%d\n", chap->id);
+	/*
+	 * Generate Challenge.
+	 */
+	chap_gen_challenge(conn, 1, aic_str, aic_len);
+
+	return chap;
+}
+
+static void chap_close(struct iscsi_conn *conn)
+{
+	kfree(conn->auth_protocol);
+	conn->auth_protocol = NULL;
+}
+
+static int chap_server_compute_md5(
+	struct iscsi_conn *conn,
+	struct iscsi_node_auth *auth,
+	char *nr_in_ptr,
+	char *nr_out_ptr,
+	unsigned int *nr_out_len)
+{
+	char *endptr;
+	unsigned char id, digest[MD5_SIGNATURE_SIZE];
+	unsigned char type, response[MD5_SIGNATURE_SIZE * 2 + 2];
+	unsigned char identifier[10], *challenge = NULL;
+	unsigned char *challenge_binhex = NULL;
+	unsigned char client_digest[MD5_SIGNATURE_SIZE];
+	unsigned char server_digest[MD5_SIGNATURE_SIZE];
+	unsigned char chap_n[MAX_CHAP_N_SIZE], chap_r[MAX_RESPONSE_LENGTH];
+	struct iscsi_chap *chap = (struct iscsi_chap *) conn->auth_protocol;
+	struct crypto_hash *tfm;
+	struct hash_desc desc;
+	struct scatterlist sg;
+	int auth_ret = -1, ret, challenge_len;
+
+	memset(identifier, 0, 10);
+	memset(chap_n, 0, MAX_CHAP_N_SIZE);
+	memset(chap_r, 0, MAX_RESPONSE_LENGTH);
+	memset(digest, 0, MD5_SIGNATURE_SIZE);
+	memset(response, 0, MD5_SIGNATURE_SIZE * 2 + 2);
+	memset(client_digest, 0, MD5_SIGNATURE_SIZE);
+	memset(server_digest, 0, MD5_SIGNATURE_SIZE);
+
+	challenge = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
+	if (!challenge) {
+		pr_err("Unable to allocate challenge buffer\n");
+		goto out;
+	}
+
+	challenge_binhex = kzalloc(CHAP_CHALLENGE_STR_LEN, GFP_KERNEL);
+	if (!challenge_binhex) {
+		pr_err("Unable to allocate challenge_binhex buffer\n");
+		goto out;
+	}
+	/*
+	 * Extract CHAP_N.
+	 */
+	if (extract_param(nr_in_ptr, "CHAP_N", MAX_CHAP_N_SIZE, chap_n,
+				&type) < 0) {
+		pr_err("Could not find CHAP_N.\n");
+		goto out;
+	}
+	if (type == HEX) {
+		pr_err("Could not find CHAP_N.\n");
+		goto out;
+	}
+
+	if (memcmp(chap_n, auth->userid, strlen(auth->userid)) != 0) {
+		pr_err("CHAP_N values do not match!\n");
+		goto out;
+	}
+	pr_debug("[server] Got CHAP_N=%s\n", chap_n);
+	/*
+	 * Extract CHAP_R.
+	 */
+	if (extract_param(nr_in_ptr, "CHAP_R", MAX_RESPONSE_LENGTH, chap_r,
+				&type) < 0) {
+		pr_err("Could not find CHAP_R.\n");
+		goto out;
+	}
+	if (type != HEX) {
+		pr_err("Could not find CHAP_R.\n");
+		goto out;
+	}
+
+	pr_debug("[server] Got CHAP_R=%s\n", chap_r);
+	chap_string_to_hex(client_digest, chap_r, strlen(chap_r));
+
+	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm)) {
+		pr_err("Unable to allocate struct crypto_hash\n");
+		goto out;
+	}
+	desc.tfm = tfm;
+	desc.flags = 0;
+
+	ret = crypto_hash_init(&desc);
+	if (ret < 0) {
+		pr_err("crypto_hash_init() failed\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	sg_init_one(&sg, (void *)&chap->id, 1);
+	ret = crypto_hash_update(&desc, &sg, 1);
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for id\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	sg_init_one(&sg, (void *)&auth->password, strlen(auth->password));
+	ret = crypto_hash_update(&desc, &sg, strlen(auth->password));
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for password\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	sg_init_one(&sg, (void *)chap->challenge, CHAP_CHALLENGE_LENGTH);
+	ret = crypto_hash_update(&desc, &sg, CHAP_CHALLENGE_LENGTH);
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for challenge\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	ret = crypto_hash_final(&desc, server_digest);
+	if (ret < 0) {
+		pr_err("crypto_hash_final() failed for server digest\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+	crypto_free_hash(tfm);
+
+	chap_binaryhex_to_asciihex(response, server_digest, MD5_SIGNATURE_SIZE);
+	pr_debug("[server] MD5 Server Digest: %s\n", response);
+
+	if (memcmp(server_digest, client_digest, MD5_SIGNATURE_SIZE) != 0) {
+		pr_debug("[server] MD5 Digests do not match!\n\n");
+		goto out;
+	} else
+		pr_debug("[server] MD5 Digests match, CHAP connetication"
+				" successful.\n\n");
+	/*
+	 * One way authentication has succeeded, return now if mutual
+	 * authentication is not enabled.
+	 */
+	if (!auth->authenticate_target) {
+		kfree(challenge);
+		kfree(challenge_binhex);
+		return 0;
+	}
+	/*
+	 * Get CHAP_I.
+	 */
+	if (extract_param(nr_in_ptr, "CHAP_I", 10, identifier, &type) < 0) {
+		pr_err("Could not find CHAP_I.\n");
+		goto out;
+	}
+
+	if (type == HEX)
+		id = (unsigned char)simple_strtoul((char *)&identifier[2],
+					&endptr, 0);
+	else
+		id = (unsigned char)simple_strtoul(identifier, &endptr, 0);
+	/*
+	 * RFC 1994 says Identifier is no more than octet (8 bits).
+	 */
+	pr_debug("[server] Got CHAP_I=%d\n", id);
+	/*
+	 * Get CHAP_C.
+	 */
+	if (extract_param(nr_in_ptr, "CHAP_C", CHAP_CHALLENGE_STR_LEN,
+			challenge, &type) < 0) {
+		pr_err("Could not find CHAP_C.\n");
+		goto out;
+	}
+
+	if (type != HEX) {
+		pr_err("Could not find CHAP_C.\n");
+		goto out;
+	}
+	pr_debug("[server] Got CHAP_C=%s\n", challenge);
+	challenge_len = chap_string_to_hex(challenge_binhex, challenge,
+				strlen(challenge));
+	if (!challenge_len) {
+		pr_err("Unable to convert incoming challenge\n");
+		goto out;
+	}
+	/*
+	 * Generate CHAP_N and CHAP_R for mutual authentication.
+	 */
+	tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm)) {
+		pr_err("Unable to allocate struct crypto_hash\n");
+		goto out;
+	}
+	desc.tfm = tfm;
+	desc.flags = 0;
+
+	ret = crypto_hash_init(&desc);
+	if (ret < 0) {
+		pr_err("crypto_hash_init() failed\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	sg_init_one(&sg, (void *)&id, 1);
+	ret = crypto_hash_update(&desc, &sg, 1);
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for id\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	sg_init_one(&sg, (void *)auth->password_mutual,
+				strlen(auth->password_mutual));
+	ret = crypto_hash_update(&desc, &sg, strlen(auth->password_mutual));
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for"
+				" password_mutual\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+	/*
+	 * Convert received challenge to binary hex.
+	 */
+	sg_init_one(&sg, (void *)challenge_binhex, challenge_len);
+	ret = crypto_hash_update(&desc, &sg, challenge_len);
+	if (ret < 0) {
+		pr_err("crypto_hash_update() failed for ma challenge\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+
+	ret = crypto_hash_final(&desc, digest);
+	if (ret < 0) {
+		pr_err("crypto_hash_final() failed for ma digest\n");
+		crypto_free_hash(tfm);
+		goto out;
+	}
+	crypto_free_hash(tfm);
+	/*
+	 * Generate CHAP_N and CHAP_R.
+	 */
+	*nr_out_len = sprintf(nr_out_ptr, "CHAP_N=%s", auth->userid_mutual);
+	*nr_out_len += 1;
+	pr_debug("[server] Sending CHAP_N=%s\n", auth->userid_mutual);
+	/*
+	 * Convert response from binary hex to ascii hext.
+	 */
+	chap_binaryhex_to_asciihex(response, digest, MD5_SIGNATURE_SIZE);
+	*nr_out_len += sprintf(nr_out_ptr + *nr_out_len, "CHAP_R=0x%s",
+			response);
+	*nr_out_len += 1;
+	pr_debug("[server] Sending CHAP_R=0x%s\n", response);
+	auth_ret = 0;
+out:
+	kfree(challenge);
+	kfree(challenge_binhex);
+	return auth_ret;
+}
+
+static int chap_got_response(
+	struct iscsi_conn *conn,
+	struct iscsi_node_auth *auth,
+	char *nr_in_ptr,
+	char *nr_out_ptr,
+	unsigned int *nr_out_len)
+{
+	struct iscsi_chap *chap = (struct iscsi_chap *) conn->auth_protocol;
+
+	switch (chap->digest_type) {
+	case CHAP_DIGEST_MD5:
+		if (chap_server_compute_md5(conn, auth, nr_in_ptr,
+				nr_out_ptr, nr_out_len) < 0)
+			return -1;
+		return 0;
+	default:
+		pr_err("Unknown CHAP digest type %d!\n",
+				chap->digest_type);
+		return -1;
+	}
+}
+
+u32 chap_main_loop(
+	struct iscsi_conn *conn,
+	struct iscsi_node_auth *auth,
+	char *in_text,
+	char *out_text,
+	int *in_len,
+	int *out_len)
+{
+	struct iscsi_chap *chap = (struct iscsi_chap *) conn->auth_protocol;
+
+	if (!chap) {
+		chap = chap_server_open(conn, auth, in_text, out_text, out_len);
+		if (!chap)
+			return 2;
+		chap->chap_state = CHAP_STAGE_SERVER_AIC;
+		return 0;
+	} else if (chap->chap_state == CHAP_STAGE_SERVER_AIC) {
+		convert_null_to_semi(in_text, *in_len);
+		if (chap_got_response(conn, auth, in_text, out_text,
+				out_len) < 0) {
+			chap_close(conn);
+			return 2;
+		}
+		if (auth->authenticate_target)
+			chap->chap_state = CHAP_STAGE_SERVER_NR;
+		else
+			*out_len = 0;
+		chap_close(conn);
+		return 1;
+	}
+
+	return 2;
+}

drivers/target/iscsi/iscsi_target_auth.h

@@ -0,0 +1,31 @@
+#ifndef _ISCSI_CHAP_H_
+#define _ISCSI_CHAP_H_
+
+#define CHAP_DIGEST_MD5		5
+#define CHAP_DIGEST_SHA		6
+
+#define CHAP_CHALLENGE_LENGTH	16
+#define CHAP_CHALLENGE_STR_LEN	4096
+#define MAX_RESPONSE_LENGTH	64	/* sufficient for MD5 */
+#define	MAX_CHAP_N_SIZE		512
+
+#define MD5_SIGNATURE_SIZE	16	/* 16 bytes in a MD5 message digest */
+
+#define CHAP_STAGE_CLIENT_A	1
+#define CHAP_STAGE_SERVER_AIC	2
+#define CHAP_STAGE_CLIENT_NR	3
+#define CHAP_STAGE_CLIENT_NRIC	4
+#define CHAP_STAGE_SERVER_NR	5
+
+extern u32 chap_main_loop(struct iscsi_conn *, struct iscsi_node_auth *, char *, char *,
+				int *, int *);
+
+struct iscsi_chap {
+	unsigned char	digest_type;
+	unsigned char	id;
+	unsigned char	challenge[CHAP_CHALLENGE_LENGTH];
+	unsigned int	authenticate_target;
+	unsigned int	chap_state;
+} ____cacheline_aligned;
+
+#endif   /*** _ISCSI_CHAP_H_ ***/

drivers/target/iscsi/iscsi_target_configfs.h

@@ -0,0 +1,7 @@
+#ifndef ISCSI_TARGET_CONFIGFS_H
+#define ISCSI_TARGET_CONFIGFS_H
+
+extern int iscsi_target_register_configfs(void);
+extern void iscsi_target_deregister_configfs(void);
+
+#endif /* ISCSI_TARGET_CONFIGFS_H */

drivers/target/iscsi/iscsi_target_datain_values.h

@@ -0,0 +1,12 @@
+#ifndef ISCSI_TARGET_DATAIN_VALUES_H
+#define ISCSI_TARGET_DATAIN_VALUES_H
+
+extern struct iscsi_datain_req *iscsit_allocate_datain_req(void);
+extern void iscsit_attach_datain_req(struct iscsi_cmd *, struct iscsi_datain_req *);
+extern void iscsit_free_datain_req(struct iscsi_cmd *, struct iscsi_datain_req *);
+extern void iscsit_free_all_datain_reqs(struct iscsi_cmd *);
+extern struct iscsi_datain_req *iscsit_get_datain_req(struct iscsi_cmd *);
+extern struct iscsi_datain_req *iscsit_get_datain_values(struct iscsi_cmd *,
+			struct iscsi_datain *);
+
+#endif   /*** ISCSI_TARGET_DATAIN_VALUES_H ***/

drivers/target/iscsi/iscsi_target_device.c

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * This file contains the iSCSI Virtual Device and Disk Transport
+ * agnostic related functions.
+ *
+ \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 <scsi/scsi_device.h>
+#include <target/target_core_base.h>
+#include <target/target_core_device.h>
+#include <target/target_core_transport.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_device.h"
+#include "iscsi_target_tpg.h"
+#include "iscsi_target_util.h"
+
+int iscsit_get_lun_for_tmr(
+	struct iscsi_cmd *cmd,
+	u64 lun)
+{
+	u32 unpacked_lun = scsilun_to_int((struct scsi_lun *)&lun);
+
+	return transport_lookup_tmr_lun(&cmd->se_cmd, unpacked_lun);
+}
+
+int iscsit_get_lun_for_cmd(
+	struct iscsi_cmd *cmd,
+	unsigned char *cdb,
+	u64 lun)
+{
+	u32 unpacked_lun = scsilun_to_int((struct scsi_lun *)&lun);
+
+	return transport_lookup_cmd_lun(&cmd->se_cmd, unpacked_lun);
+}
+
+void iscsit_determine_maxcmdsn(struct iscsi_session *sess)
+{
+	struct se_node_acl *se_nacl;
+
+	/*
+	 * This is a discovery session, the single queue slot was already
+	 * assigned in iscsi_login_zero_tsih().  Since only Logout and
+	 * Text Opcodes are allowed during discovery we do not have to worry
+	 * about the HBA's queue depth here.
+	 */
+	if (sess->sess_ops->SessionType)
+		return;
+
+	se_nacl = sess->se_sess->se_node_acl;
+
+	/*
+	 * This is a normal session, set the Session's CmdSN window to the
+	 * struct se_node_acl->queue_depth.  The value in struct se_node_acl->queue_depth
+	 * has already been validated as a legal value in
+	 * core_set_queue_depth_for_node().
+	 */
+	sess->cmdsn_window = se_nacl->queue_depth;
+	sess->max_cmd_sn = (sess->max_cmd_sn + se_nacl->queue_depth) - 1;
+}
+
+void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
+{
+	if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
+		return;
+
+	cmd->maxcmdsn_inc = 1;
+
+	mutex_lock(&sess->cmdsn_mutex);
+	sess->max_cmd_sn += 1;
+	pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
+	mutex_unlock(&sess->cmdsn_mutex);
+}

drivers/target/iscsi/iscsi_target_device.h

@@ -0,0 +1,9 @@
+#ifndef ISCSI_TARGET_DEVICE_H
+#define ISCSI_TARGET_DEVICE_H
+
+extern int iscsit_get_lun_for_tmr(struct iscsi_cmd *, u64);
+extern int iscsit_get_lun_for_cmd(struct iscsi_cmd *, unsigned char *, u64);
+extern void iscsit_determine_maxcmdsn(struct iscsi_session *);
+extern void iscsit_increment_maxcmdsn(struct iscsi_cmd *, struct iscsi_session *);
+
+#endif /* ISCSI_TARGET_DEVICE_H */

drivers/target/iscsi/iscsi_target_erl0.h

@@ -0,0 +1,15 @@
+#ifndef ISCSI_TARGET_ERL0_H
+#define ISCSI_TARGET_ERL0_H
+
+extern void iscsit_set_dataout_sequence_values(struct iscsi_cmd *);
+extern int iscsit_check_pre_dataout(struct iscsi_cmd *, unsigned char *);
+extern int iscsit_check_post_dataout(struct iscsi_cmd *, unsigned char *, u8);
+extern void iscsit_start_time2retain_handler(struct iscsi_session *);
+extern int iscsit_stop_time2retain_timer(struct iscsi_session *);
+extern void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *);
+extern void iscsit_cause_connection_reinstatement(struct iscsi_conn *, int);
+extern void iscsit_fall_back_to_erl0(struct iscsi_session *);
+extern void iscsit_take_action_for_connection_exit(struct iscsi_conn *);
+extern int iscsit_recover_from_unknown_opcode(struct iscsi_conn *);
+
+#endif   /*** ISCSI_TARGET_ERL0_H ***/

drivers/target/iscsi/iscsi_target_erl1.h

@@ -0,0 +1,26 @@
+#ifndef ISCSI_TARGET_ERL1_H
+#define ISCSI_TARGET_ERL1_H
+
+extern int iscsit_dump_data_payload(struct iscsi_conn *, u32, int);
+extern int iscsit_create_recovery_datain_values_datasequenceinorder_yes(
+			struct iscsi_cmd *, struct iscsi_datain_req *);
+extern int iscsit_create_recovery_datain_values_datasequenceinorder_no(
+			struct iscsi_cmd *, struct iscsi_datain_req *);
+extern int iscsit_handle_recovery_datain_or_r2t(struct iscsi_conn *, unsigned char *,
+			u32, u32, u32, u32);
+extern int iscsit_handle_status_snack(struct iscsi_conn *, u32, u32,
+			u32, u32);
+extern int iscsit_handle_data_ack(struct iscsi_conn *, u32, u32, u32);
+extern int iscsit_dataout_datapduinorder_no_fbit(struct iscsi_cmd *, struct iscsi_pdu *);
+extern int iscsit_recover_dataout_sequence(struct iscsi_cmd *, u32, u32);
+extern void iscsit_clear_ooo_cmdsns_for_conn(struct iscsi_conn *);
+extern void iscsit_free_all_ooo_cmdsns(struct iscsi_session *);
+extern int iscsit_execute_ooo_cmdsns(struct iscsi_session *);
+extern int iscsit_execute_cmd(struct iscsi_cmd *, int);
+extern int iscsit_handle_ooo_cmdsn(struct iscsi_session *, struct iscsi_cmd *, u32);
+extern void iscsit_remove_ooo_cmdsn(struct iscsi_session *, struct iscsi_ooo_cmdsn *);
+extern void iscsit_mod_dataout_timer(struct iscsi_cmd *);
+extern void iscsit_start_dataout_timer(struct iscsi_cmd *, struct iscsi_conn *);
+extern void iscsit_stop_dataout_timer(struct iscsi_cmd *);
+
+#endif /* ISCSI_TARGET_ERL1_H */

drivers/target/iscsi/iscsi_target_erl2.c

@@ -0,0 +1,474 @@
+/*******************************************************************************
+ * This file contains error recovery level two functions used by
+ * the iSCSI Target driver.
+ *
+ * \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 <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_transport.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_datain_values.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target_erl0.h"
+#include "iscsi_target_erl1.h"
+#include "iscsi_target_erl2.h"
+#include "iscsi_target.h"
+
+/*
+ *	FIXME: Does RData SNACK apply here as well?
+ */
+void iscsit_create_conn_recovery_datain_values(
+	struct iscsi_cmd *cmd,
+	u32 exp_data_sn)
+{
+	u32 data_sn = 0;
+	struct iscsi_conn *conn = cmd->conn;
+
+	cmd->next_burst_len = 0;
+	cmd->read_data_done = 0;
+
+	while (exp_data_sn > data_sn) {
+		if ((cmd->next_burst_len +
+		     conn->conn_ops->MaxRecvDataSegmentLength) <
+		     conn->sess->sess_ops->MaxBurstLength) {
+			cmd->read_data_done +=
+			       conn->conn_ops->MaxRecvDataSegmentLength;
+			cmd->next_burst_len +=
+			       conn->conn_ops->MaxRecvDataSegmentLength;
+		} else {
+			cmd->read_data_done +=
+				(conn->sess->sess_ops->MaxBurstLength -
+				cmd->next_burst_len);
+			cmd->next_burst_len = 0;
+		}
+		data_sn++;
+	}
+}
+
+void iscsit_create_conn_recovery_dataout_values(
+	struct iscsi_cmd *cmd)
+{
+	u32 write_data_done = 0;
+	struct iscsi_conn *conn = cmd->conn;
+
+	cmd->data_sn = 0;
+	cmd->next_burst_len = 0;
+
+	while (cmd->write_data_done > write_data_done) {
+		if ((write_data_done + conn->sess->sess_ops->MaxBurstLength) <=
+		     cmd->write_data_done)
+			write_data_done += conn->sess->sess_ops->MaxBurstLength;
+		else
+			break;
+	}
+
+	cmd->write_data_done = write_data_done;
+}
+
+static int iscsit_attach_active_connection_recovery_entry(
+	struct iscsi_session *sess,
+	struct iscsi_conn_recovery *cr)
+{
+	spin_lock(&sess->cr_a_lock);
+	list_add_tail(&cr->cr_list, &sess->cr_active_list);
+	spin_unlock(&sess->cr_a_lock);
+
+	return 0;
+}
+
+static int iscsit_attach_inactive_connection_recovery_entry(
+	struct iscsi_session *sess,
+	struct iscsi_conn_recovery *cr)
+{
+	spin_lock(&sess->cr_i_lock);
+	list_add_tail(&cr->cr_list, &sess->cr_inactive_list);
+
+	sess->conn_recovery_count++;
+	pr_debug("Incremented connection recovery count to %u for"
+		" SID: %u\n", sess->conn_recovery_count, sess->sid);
+	spin_unlock(&sess->cr_i_lock);
+
+	return 0;
+}
+
+struct iscsi_conn_recovery *iscsit_get_inactive_connection_recovery_entry(
+	struct iscsi_session *sess,
+	u16 cid)
+{
+	struct iscsi_conn_recovery *cr;
+
+	spin_lock(&sess->cr_i_lock);
+	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
+		if (cr->cid == cid) {
+			spin_unlock(&sess->cr_i_lock);
+			return cr;
+		}
+	}
+	spin_unlock(&sess->cr_i_lock);
+
+	return NULL;
+}
+
+void iscsit_free_connection_recovery_entires(struct iscsi_session *sess)
+{
+	struct iscsi_cmd *cmd, *cmd_tmp;
+	struct iscsi_conn_recovery *cr, *cr_tmp;
+
+	spin_lock(&sess->cr_a_lock);
+	list_for_each_entry_safe(cr, cr_tmp, &sess->cr_active_list, cr_list) {
+		list_del(&cr->cr_list);
+		spin_unlock(&sess->cr_a_lock);
+
+		spin_lock(&cr->conn_recovery_cmd_lock);
+		list_for_each_entry_safe(cmd, cmd_tmp,
+				&cr->conn_recovery_cmd_list, i_list) {
+
+			list_del(&cmd->i_list);
+			cmd->conn = NULL;
+			spin_unlock(&cr->conn_recovery_cmd_lock);
+			if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+			    !(cmd->se_cmd.transport_wait_for_tasks))
+				iscsit_release_cmd(cmd);
+			else
+				cmd->se_cmd.transport_wait_for_tasks(
+						&cmd->se_cmd, 1, 1);
+			spin_lock(&cr->conn_recovery_cmd_lock);
+		}
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+		spin_lock(&sess->cr_a_lock);
+
+		kfree(cr);
+	}
+	spin_unlock(&sess->cr_a_lock);
+
+	spin_lock(&sess->cr_i_lock);
+	list_for_each_entry_safe(cr, cr_tmp, &sess->cr_inactive_list, cr_list) {
+		list_del(&cr->cr_list);
+		spin_unlock(&sess->cr_i_lock);
+
+		spin_lock(&cr->conn_recovery_cmd_lock);
+		list_for_each_entry_safe(cmd, cmd_tmp,
+				&cr->conn_recovery_cmd_list, i_list) {
+
+			list_del(&cmd->i_list);
+			cmd->conn = NULL;
+			spin_unlock(&cr->conn_recovery_cmd_lock);
+			if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+			    !(cmd->se_cmd.transport_wait_for_tasks))
+				iscsit_release_cmd(cmd);
+			else
+				cmd->se_cmd.transport_wait_for_tasks(
+						&cmd->se_cmd, 1, 1);
+			spin_lock(&cr->conn_recovery_cmd_lock);
+		}
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+		spin_lock(&sess->cr_i_lock);
+
+		kfree(cr);
+	}
+	spin_unlock(&sess->cr_i_lock);
+}
+
+int iscsit_remove_active_connection_recovery_entry(
+	struct iscsi_conn_recovery *cr,
+	struct iscsi_session *sess)
+{
+	spin_lock(&sess->cr_a_lock);
+	list_del(&cr->cr_list);
+
+	sess->conn_recovery_count--;
+	pr_debug("Decremented connection recovery count to %u for"
+		" SID: %u\n", sess->conn_recovery_count, sess->sid);
+	spin_unlock(&sess->cr_a_lock);
+
+	kfree(cr);
+
+	return 0;
+}
+
+int iscsit_remove_inactive_connection_recovery_entry(
+	struct iscsi_conn_recovery *cr,
+	struct iscsi_session *sess)
+{
+	spin_lock(&sess->cr_i_lock);
+	list_del(&cr->cr_list);
+	spin_unlock(&sess->cr_i_lock);
+
+	return 0;
+}
+
+/*
+ *	Called with cr->conn_recovery_cmd_lock help.
+ */
+int iscsit_remove_cmd_from_connection_recovery(
+	struct iscsi_cmd *cmd,
+	struct iscsi_session *sess)
+{
+	struct iscsi_conn_recovery *cr;
+
+	if (!cmd->cr) {
+		pr_err("struct iscsi_conn_recovery pointer for ITT: 0x%08x"
+			" is NULL!\n", cmd->init_task_tag);
+		BUG();
+	}
+	cr = cmd->cr;
+
+	list_del(&cmd->i_list);
+	return --cr->cmd_count;
+}
+
+void iscsit_discard_cr_cmds_by_expstatsn(
+	struct iscsi_conn_recovery *cr,
+	u32 exp_statsn)
+{
+	u32 dropped_count = 0;
+	struct iscsi_cmd *cmd, *cmd_tmp;
+	struct iscsi_session *sess = cr->sess;
+
+	spin_lock(&cr->conn_recovery_cmd_lock);
+	list_for_each_entry_safe(cmd, cmd_tmp,
+			&cr->conn_recovery_cmd_list, i_list) {
+
+		if (((cmd->deferred_i_state != ISTATE_SENT_STATUS) &&
+		     (cmd->deferred_i_state != ISTATE_REMOVE)) ||
+		     (cmd->stat_sn >= exp_statsn)) {
+			continue;
+		}
+
+		dropped_count++;
+		pr_debug("Dropping Acknowledged ITT: 0x%08x, StatSN:"
+			" 0x%08x, CID: %hu.\n", cmd->init_task_tag,
+				cmd->stat_sn, cr->cid);
+
+		iscsit_remove_cmd_from_connection_recovery(cmd, sess);
+
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+		if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+		    !(cmd->se_cmd.transport_wait_for_tasks))
+			iscsit_release_cmd(cmd);
+		else
+			cmd->se_cmd.transport_wait_for_tasks(
+					&cmd->se_cmd, 1, 0);
+		spin_lock(&cr->conn_recovery_cmd_lock);
+	}
+	spin_unlock(&cr->conn_recovery_cmd_lock);
+
+	pr_debug("Dropped %u total acknowledged commands on"
+		" CID: %hu less than old ExpStatSN: 0x%08x\n",
+			dropped_count, cr->cid, exp_statsn);
+
+	if (!cr->cmd_count) {
+		pr_debug("No commands to be reassigned for failed"
+			" connection CID: %hu on SID: %u\n",
+			cr->cid, sess->sid);
+		iscsit_remove_inactive_connection_recovery_entry(cr, sess);
+		iscsit_attach_active_connection_recovery_entry(sess, cr);
+		pr_debug("iSCSI connection recovery successful for CID:"
+			" %hu on SID: %u\n", cr->cid, sess->sid);
+		iscsit_remove_active_connection_recovery_entry(cr, sess);
+	} else {
+		iscsit_remove_inactive_connection_recovery_entry(cr, sess);
+		iscsit_attach_active_connection_recovery_entry(sess, cr);
+	}
+}
+
+int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn)
+{
+	u32 dropped_count = 0;
+	struct iscsi_cmd *cmd, *cmd_tmp;
+	struct iscsi_ooo_cmdsn *ooo_cmdsn, *ooo_cmdsn_tmp;
+	struct iscsi_session *sess = conn->sess;
+
+	mutex_lock(&sess->cmdsn_mutex);
+	list_for_each_entry_safe(ooo_cmdsn, ooo_cmdsn_tmp,
+			&sess->sess_ooo_cmdsn_list, ooo_list) {
+
+		if (ooo_cmdsn->cid != conn->cid)
+			continue;
+
+		dropped_count++;
+		pr_debug("Dropping unacknowledged CmdSN:"
+		" 0x%08x during connection recovery on CID: %hu\n",
+			ooo_cmdsn->cmdsn, conn->cid);
+		iscsit_remove_ooo_cmdsn(sess, ooo_cmdsn);
+	}
+	mutex_unlock(&sess->cmdsn_mutex);
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
+		if (!(cmd->cmd_flags & ICF_OOO_CMDSN))
+			continue;
+
+		list_del(&cmd->i_list);
+
+		spin_unlock_bh(&conn->cmd_lock);
+		if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+		    !(cmd->se_cmd.transport_wait_for_tasks))
+			iscsit_release_cmd(cmd);
+		else
+			cmd->se_cmd.transport_wait_for_tasks(
+					&cmd->se_cmd, 1, 1);
+		spin_lock_bh(&conn->cmd_lock);
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+
+	pr_debug("Dropped %u total unacknowledged commands on CID:"
+		" %hu for ExpCmdSN: 0x%08x.\n", dropped_count, conn->cid,
+				sess->exp_cmd_sn);
+	return 0;
+}
+
+int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
+{
+	u32 cmd_count = 0;
+	struct iscsi_cmd *cmd, *cmd_tmp;
+	struct iscsi_conn_recovery *cr;
+
+	/*
+	 * Allocate an struct iscsi_conn_recovery for this connection.
+	 * Each struct iscsi_cmd contains an struct iscsi_conn_recovery pointer
+	 * (struct iscsi_cmd->cr) so we need to allocate this before preparing the
+	 * connection's command list for connection recovery.
+	 */
+	cr = kzalloc(sizeof(struct iscsi_conn_recovery), GFP_KERNEL);
+	if (!cr) {
+		pr_err("Unable to allocate memory for"
+			" struct iscsi_conn_recovery.\n");
+		return -1;
+	}
+	INIT_LIST_HEAD(&cr->cr_list);
+	INIT_LIST_HEAD(&cr->conn_recovery_cmd_list);
+	spin_lock_init(&cr->conn_recovery_cmd_lock);
+	/*
+	 * Only perform connection recovery on ISCSI_OP_SCSI_CMD or
+	 * ISCSI_OP_NOOP_OUT opcodes.  For all other opcodes call
+	 * list_del(&cmd->i_list); to release the command to the
+	 * session pool and remove it from the connection's list.
+	 *
+	 * Also stop the DataOUT timer, which will be restarted after
+	 * sending the TMR response.
+	 */
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry_safe(cmd, cmd_tmp, &conn->conn_cmd_list, i_list) {
+
+		if ((cmd->iscsi_opcode != ISCSI_OP_SCSI_CMD) &&
+		    (cmd->iscsi_opcode != ISCSI_OP_NOOP_OUT)) {
+			pr_debug("Not performing realligence on"
+				" Opcode: 0x%02x, ITT: 0x%08x, CmdSN: 0x%08x,"
+				" CID: %hu\n", cmd->iscsi_opcode,
+				cmd->init_task_tag, cmd->cmd_sn, conn->cid);
+
+			list_del(&cmd->i_list);
+			spin_unlock_bh(&conn->cmd_lock);
+
+			if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+			    !(cmd->se_cmd.transport_wait_for_tasks))
+				iscsit_release_cmd(cmd);
+			else
+				cmd->se_cmd.transport_wait_for_tasks(
+						&cmd->se_cmd, 1, 0);
+			spin_lock_bh(&conn->cmd_lock);
+			continue;
+		}
+
+		/*
+		 * Special case where commands greater than or equal to
+		 * the session's ExpCmdSN are attached to the connection
+		 * list but not to the out of order CmdSN list.  The one
+		 * obvious case is when a command with immediate data
+		 * attached must only check the CmdSN against ExpCmdSN
+		 * after the data is received.  The special case below
+		 * is when the connection fails before data is received,
+		 * but also may apply to other PDUs, so it has been
+		 * made generic here.
+		 */
+		if (!(cmd->cmd_flags & ICF_OOO_CMDSN) && !cmd->immediate_cmd &&
+		     (cmd->cmd_sn >= conn->sess->exp_cmd_sn)) {
+			list_del(&cmd->i_list);
+			spin_unlock_bh(&conn->cmd_lock);
+
+			if (!(cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) ||
+			    !(cmd->se_cmd.transport_wait_for_tasks))
+				iscsit_release_cmd(cmd);
+			else
+				cmd->se_cmd.transport_wait_for_tasks(
+						&cmd->se_cmd, 1, 1);
+			spin_lock_bh(&conn->cmd_lock);
+			continue;
+		}
+
+		cmd_count++;
+		pr_debug("Preparing Opcode: 0x%02x, ITT: 0x%08x,"
+			" CmdSN: 0x%08x, StatSN: 0x%08x, CID: %hu for"
+			" realligence.\n", cmd->iscsi_opcode,
+			cmd->init_task_tag, cmd->cmd_sn, cmd->stat_sn,
+			conn->cid);
+
+		cmd->deferred_i_state = cmd->i_state;
+		cmd->i_state = ISTATE_IN_CONNECTION_RECOVERY;
+
+		if (cmd->data_direction == DMA_TO_DEVICE)
+			iscsit_stop_dataout_timer(cmd);
+
+		cmd->sess = conn->sess;
+
+		list_del(&cmd->i_list);
+		spin_unlock_bh(&conn->cmd_lock);
+
+		iscsit_free_all_datain_reqs(cmd);
+
+		if ((cmd->se_cmd.se_cmd_flags & SCF_SE_LUN_CMD) &&
+		     cmd->se_cmd.transport_wait_for_tasks)
+			cmd->se_cmd.transport_wait_for_tasks(&cmd->se_cmd,
+					0, 0);
+		/*
+		 * Add the struct iscsi_cmd to the connection recovery cmd list
+		 */
+		spin_lock(&cr->conn_recovery_cmd_lock);
+		list_add_tail(&cmd->i_list, &cr->conn_recovery_cmd_list);
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+
+		spin_lock_bh(&conn->cmd_lock);
+		cmd->cr = cr;
+		cmd->conn = NULL;
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+	/*
+	 * Fill in the various values in the preallocated struct iscsi_conn_recovery.
+	 */
+	cr->cid = conn->cid;
+	cr->cmd_count = cmd_count;
+	cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
+	cr->sess = conn->sess;
+
+	iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
+
+	return 0;
+}
+
+int iscsit_connection_recovery_transport_reset(struct iscsi_conn *conn)
+{
+	atomic_set(&conn->connection_recovery, 1);
+
+	if (iscsit_close_connection(conn) < 0)
+		return -1;
+
+	return 0;
+}