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/*

 * iSCSI transport class definitions

 *

 * Copyright (C) IBM Corporation, 2004

 * Copyright (C) Mike Christie, 2004 - 2006

 * Copyright (C) Dmitry Yusupov, 2004 - 2005

 * Copyright (C) Alex Aizman, 2004 - 2005

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 */

#ifndef SCSI_TRANSPORT_ISCSI_H

#define SCSI_TRANSPORT_ISCSI_H

#include <linux/device.h>

#include <linux/list.h>

#include <linux/mutex.h>

#include <scsi/iscsi_if.h>

struct scsi_transport_template;

struct iscsi_transport;

struct Scsi_Host;

struct iscsi_cls_conn;

struct iscsi_conn;

struct iscsi_cmd_task;

struct iscsi_mgmt_task;

struct sockaddr;

/**

 * struct iscsi_transport - iSCSI Transport template

 *

 * @name:               transport name

 * @caps:               iSCSI Data-Path capabilities

 * @create_session:     create new iSCSI session object

 * @destroy_session:    destroy existing iSCSI session object

 * @create_conn:        create new iSCSI connection

 * @bind_conn:          associate this connection with existing iSCSI session

 *                      and specified transport descriptor

 * @destroy_conn:       destroy inactive iSCSI connection

 * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA

 *                      when param is not supported, and a -Exx value on other

 *                      error.

 * @get_param           get iSCSI parameter. Must return number of bytes

 *                      copied to buffer on success, -ENODATA when param

 *                      is not supported, and a -Exx value on other error

 * @start_conn:         set connection to be operational

 * @stop_conn:          suspend/recover/terminate connection

 * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.

 * @session_recovery_timedout: notify LLD a block during recovery timed out

 * @init_cmd_task:      Initialize a iscsi_cmd_task and any internal structs.

 *                      Called from queuecommand with session lock held.

 * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.

 *                      Called from iscsi_conn_send_generic with xmitmutex.

 * @xmit_cmd_task:      Requests LLD to transfer cmd task. Returns 0 or the

 *                      the number of bytes transferred on success, and -Exyz

 *                      value on error.

 * @xmit_mgmt_task:     Requests LLD to transfer mgmt task. Returns 0 or the

 *                      the number of bytes transferred on success, and -Exyz

 *                      value on error.

 * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex

 *                      and session->lock after the connection has been

 *                      suspended and terminated during recovery. If called

 *                      from abort task then connection is not suspended

 *                      or terminated but sk_callback_lock is held

 *

 * Template API provided by iSCSI Transport

 */

struct iscsi_transport {

        struct module *owner;

        char *name;

        unsigned int caps;

        /* LLD sets this to indicate what values it can export to sysfs */

        uint64_t param_mask;

        uint64_t host_param_mask;

        struct scsi_host_template *host_template;

        /* LLD connection data size */

        int conndata_size;

        /* LLD session data size */

        int sessiondata_size;

        int max_lun;

        unsigned int max_conn;

        unsigned int max_cmd_len;

        struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,

                struct scsi_transport_template *t, uint16_t, uint16_t,

                uint32_t sn, uint32_t *hn);

        void (*destroy_session) (struct iscsi_cls_session *session);

        struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,

                                uint32_t cid);

        int (*bind_conn) (struct iscsi_cls_session *session,

                          struct iscsi_cls_conn *cls_conn,

                          uint64_t transport_eph, int is_leading);

        int (*start_conn) (struct iscsi_cls_conn *conn);

        void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);

        void (*destroy_conn) (struct iscsi_cls_conn *conn);

        int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,

                          char *buf, int buflen);

        int (*get_conn_param) (struct iscsi_cls_conn *conn,

                               enum iscsi_param param, char *buf);

        int (*get_session_param) (struct iscsi_cls_session *session,

                                  enum iscsi_param param, char *buf);

        int (*get_host_param) (struct Scsi_Host *shost,

                                enum iscsi_host_param param, char *buf);

        int (*set_host_param) (struct Scsi_Host *shost,

                               enum iscsi_host_param param, char *buf,

                               int buflen);

        int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,

                         char *data, uint32_t data_size);

        void (*get_stats) (struct iscsi_cls_conn *conn,

                           struct iscsi_stats *stats);

        void (*init_cmd_task) (struct iscsi_cmd_task *ctask);

        void (*init_mgmt_task) (struct iscsi_conn *conn,

                                struct iscsi_mgmt_task *mtask);

        int (*xmit_cmd_task) (struct iscsi_conn *conn,

                              struct iscsi_cmd_task *ctask);

        void (*cleanup_cmd_task) (struct iscsi_conn *conn,

                                  struct iscsi_cmd_task *ctask);

        int (*xmit_mgmt_task) (struct iscsi_conn *conn,

                               struct iscsi_mgmt_task *mtask);

        void (*session_recovery_timedout) (struct iscsi_cls_session *session);

        int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,

                           uint64_t *ep_handle);

        int (*ep_poll) (uint64_t ep_handle, int timeout_ms);

        void (*ep_disconnect) (uint64_t ep_handle);

        int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,

                          uint32_t enable, struct sockaddr *dst_addr);

};

/*

 * transport registration upcalls

 */

extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);

extern int iscsi_unregister_transport(struct iscsi_transport *tt);

/*

 * control plane upcalls

 */

extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);

extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,

                          char *data, uint32_t data_size);

/* Connection's states */

#define ISCSI_CONN_INITIAL_STAGE        0

#define ISCSI_CONN_STARTED              1

#define ISCSI_CONN_STOPPED              2

#define ISCSI_CONN_CLEANUP_WAIT         3

struct iscsi_cls_conn {

        struct list_head conn_list;     /* item in connlist */

        void *dd_data;                  /* LLD private data */

        struct iscsi_transport *transport;

        uint32_t cid;                   /* connection id */

        int active;                     /* must be accessed with the connlock */

        struct device dev;              /* sysfs transport/container device */

};

#define iscsi_dev_to_conn(_dev) \

        container_of(_dev, struct iscsi_cls_conn, dev)

/* Session's states */

#define ISCSI_STATE_FREE                1

#define ISCSI_STATE_LOGGED_IN           2

#define ISCSI_STATE_FAILED              3

#define ISCSI_STATE_TERMINATE           4

#define ISCSI_STATE_IN_RECOVERY         5

#define ISCSI_STATE_RECOVERY_FAILED     6

struct iscsi_cls_session {

        struct list_head sess_list;             /* item in session_list */

        struct list_head host_list;

        struct iscsi_transport *transport;

        /* recovery fields */

        int recovery_tmo;

        struct delayed_work recovery_work;

        int target_id;

        int sid;                                /* session id */

        void *dd_data;                          /* LLD private data */

        struct device dev;      /* sysfs transport/container device */

};

#define iscsi_dev_to_session(_dev) \

        container_of(_dev, struct iscsi_cls_session, dev)

#define iscsi_session_to_shost(_session) \

        dev_to_shost(_session->dev.parent)

#define starget_to_session(_stgt) \

        iscsi_dev_to_session(_stgt->dev.parent)

struct iscsi_host {

        struct list_head sessions;

        struct mutex mutex;

};

/*

 * session and connection functions that can be used by HW iSCSI LLDs

 */

extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,

                                        struct iscsi_transport *transport);

extern int iscsi_add_session(struct iscsi_cls_session *session,

                             unsigned int target_id);

extern int iscsi_if_create_session_done(struct iscsi_cls_conn *conn);

extern int iscsi_if_destroy_session_done(struct iscsi_cls_conn *conn);

extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,

                                                struct iscsi_transport *t,

                                                unsigned int target_id);

extern void iscsi_remove_session(struct iscsi_cls_session *session);

extern void iscsi_free_session(struct iscsi_cls_session *session);

extern int iscsi_destroy_session(struct iscsi_cls_session *session);

extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,

                                            uint32_t cid);

extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);

extern void iscsi_unblock_session(struct iscsi_cls_session *session);

extern void iscsi_block_session(struct iscsi_cls_session *session);

#endif