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

+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

+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

+#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.h

+#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

+#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

+#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

+/*******************************************************************************
+ * 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

+#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 */