root/include/scsi/libiscsi.h

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INCLUDED FROM


DEFINITIONS

This source file includes following definitions.
  1. iscsi_task_has_unsol_data
  2. iscsi_next_hdr
  3. iscsi_padded
  4. iscsi_padding

/*
 * iSCSI lib definitions
 *
 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
 * Copyright (C) 2004 - 2006 Mike Christie
 * Copyright (C) 2004 - 2005 Dmitry Yusupov
 * Copyright (C) 2004 - 2005 Alex Aizman
 *
 * 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 LIBISCSI_H
#define LIBISCSI_H

#include <linux/types.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/kfifo.h>
#include <scsi/iscsi_proto.h>
#include <scsi/iscsi_if.h>
#include <scsi/scsi_transport_iscsi.h>

struct scsi_transport_template;
struct scsi_host_template;
struct scsi_device;
struct Scsi_Host;
struct scsi_target;
struct scsi_cmnd;
struct socket;
struct iscsi_transport;
struct iscsi_cls_session;
struct iscsi_cls_conn;
struct iscsi_session;
struct iscsi_nopin;
struct device;

#define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
#define ISCSI_MGMT_CMDS_MAX     15

#define ISCSI_DEF_CMD_PER_LUN   32

/* Task Mgmt states */
enum {
        TMF_INITIAL,
        TMF_QUEUED,
        TMF_SUCCESS,
        TMF_FAILED,
        TMF_TIMEDOUT,
        TMF_NOT_FOUND,
};

#define ISID_SIZE                       6

/* Connection suspend "bit" */
#define ISCSI_SUSPEND_BIT               1

#define ISCSI_ITT_MASK                  0x1fff
#define ISCSI_TOTAL_CMDS_MAX            4096
/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
#define ISCSI_TOTAL_CMDS_MIN            16
#define ISCSI_AGE_SHIFT                 28
#define ISCSI_AGE_MASK                  0xf

#define ISCSI_ADDRESS_BUF_LEN           64

enum {
        /* this is the maximum possible storage for AHSs */
        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
                                sizeof(struct iscsi_rlength_ahdr),
        ISCSI_DIGEST_SIZE = sizeof(__u32),
};


enum {
        ISCSI_TASK_FREE,
        ISCSI_TASK_COMPLETED,
        ISCSI_TASK_PENDING,
        ISCSI_TASK_RUNNING,
        ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
        ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
        ISCSI_TASK_REQUEUE_SCSIQ,       /* qcmd requeueing to scsi-ml */
};

struct iscsi_r2t_info {
        __be32                  ttt;            /* copied from R2T */
        __be32                  exp_statsn;     /* copied from R2T */
        uint32_t                data_length;    /* copied from R2T */
        uint32_t                data_offset;    /* copied from R2T */
        int                     data_count;     /* DATA-Out payload progress */
        int                     datasn;
        /* LLDs should set/update these values */
        int                     sent;           /* R2T sequence progress */
};

struct iscsi_task {
        /*
         * Because LLDs allocate their hdr differently, this is a pointer
         * and length to that storage. It must be setup at session
         * creation time.
         */
        struct iscsi_hdr        *hdr;
        unsigned short          hdr_max;
        unsigned short          hdr_len;        /* accumulated size of hdr used */
        /* copied values in case we need to send tmfs */
        itt_t                   hdr_itt;
        __be32                  cmdsn;
        struct scsi_lun         lun;

        int                     itt;            /* this ITT */

        unsigned                imm_count;      /* imm-data (bytes)   */
        /* offset in unsolicited stream (bytes); */
        struct iscsi_r2t_info   unsol_r2t;
        char                    *data;          /* mgmt payload */
        unsigned                data_count;
        struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
        struct iscsi_conn       *conn;          /* used connection    */

        /* data processing tracking */
        unsigned long           last_xfer;
        unsigned long           last_timeout;
        bool                    have_checked_conn;

        /* T10 protection information */
        bool                    protected;

        /* state set/tested under session->lock */
        int                     state;
        atomic_t                refcount;
        struct list_head        running;        /* running cmd list */
        void                    *dd_data;       /* driver/transport data */
};

static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
{
        return task->unsol_r2t.data_length > task->unsol_r2t.sent;
}

static inline void* iscsi_next_hdr(struct iscsi_task *task)
{
        return (void*)task->hdr + task->hdr_len;
}

/* Connection's states */
enum {
        ISCSI_CONN_INITIAL_STAGE,
        ISCSI_CONN_STARTED,
        ISCSI_CONN_STOPPED,
        ISCSI_CONN_CLEANUP_WAIT,
};

struct iscsi_conn {
        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
        void                    *dd_data;       /* iscsi_transport data */
        struct iscsi_session    *session;       /* parent session */
        /*
         * conn_stop() flag: stop to recover, stop to terminate
         */
        int                     stop_stage;
        struct timer_list       transport_timer;
        unsigned long           last_recv;
        unsigned long           last_ping;
        int                     ping_timeout;
        int                     recv_timeout;
        struct iscsi_task       *ping_task;

        /* iSCSI connection-wide sequencing */
        uint32_t                exp_statsn;
        uint32_t                statsn;

        /* control data */
        int                     id;             /* CID */
        int                     c_stage;        /* connection state */
        /*
         * Preallocated buffer for pdus that have data but do not
         * originate from scsi-ml. We never have two pdus using the
         * buffer at the same time. It is only allocated to
         * the default max recv size because the pdus we support
         * should always fit in this buffer
         */
        char                    *data;
        struct iscsi_task       *login_task;    /* mtask used for login/text */
        struct iscsi_task       *task;          /* xmit task in progress */

        /* xmit */
        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
        struct list_head        cmdqueue;       /* data-path cmd queue */
        struct list_head        requeue;        /* tasks needing another run */
        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
        unsigned long           suspend_tx;     /* suspend Tx */
        unsigned long           suspend_rx;     /* suspend Rx */

        /* abort */
        wait_queue_head_t       ehwait;         /* used in eh_abort() */
        struct iscsi_tm         tmhdr;
        struct timer_list       tmf_timer;
        int                     tmf_state;      /* see TMF_INITIAL, etc.*/

        /* negotiated params */
        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
        int                     hdrdgst_en;
        int                     datadgst_en;
        int                     ifmarker_en;
        int                     ofmarker_en;
        /* values userspace uses to id a conn */
        int                     persistent_port;
        char                    *persistent_address;

        unsigned                max_segment_size;
        unsigned                tcp_xmit_wsf;
        unsigned                tcp_recv_wsf;
        uint16_t                keepalive_tmo;
        uint16_t                local_port;
        uint8_t                 tcp_timestamp_stat;
        uint8_t                 tcp_nagle_disable;
        uint8_t                 tcp_wsf_disable;
        uint8_t                 tcp_timer_scale;
        uint8_t                 tcp_timestamp_en;
        uint8_t                 fragment_disable;
        uint8_t                 ipv4_tos;
        uint8_t                 ipv6_traffic_class;
        uint8_t                 ipv6_flow_label;
        uint8_t                 is_fw_assigned_ipv6;
        char                    *local_ipaddr;

        /* MIB-statistics */
        uint64_t                txdata_octets;
        uint64_t                rxdata_octets;
        uint32_t                scsicmd_pdus_cnt;
        uint32_t                dataout_pdus_cnt;
        uint32_t                scsirsp_pdus_cnt;
        uint32_t                datain_pdus_cnt;
        uint32_t                r2t_pdus_cnt;
        uint32_t                tmfcmd_pdus_cnt;
        int32_t                 tmfrsp_pdus_cnt;

        /* custom statistics */
        uint32_t                eh_abort_cnt;
        uint32_t                fmr_unalign_cnt;
};

struct iscsi_pool {
        struct kfifo            queue;          /* FIFO Queue */
        void                    **pool;         /* Pool of elements */
        int                     max;            /* Max number of elements */
};

/* Session's states */
enum {
        ISCSI_STATE_FREE = 1,
        ISCSI_STATE_LOGGED_IN,
        ISCSI_STATE_FAILED,
        ISCSI_STATE_TERMINATE,
        ISCSI_STATE_IN_RECOVERY,
        ISCSI_STATE_RECOVERY_FAILED,
        ISCSI_STATE_LOGGING_OUT,
};

struct iscsi_session {
        struct iscsi_cls_session *cls_session;
        /*
         * Syncs up the scsi eh thread with the iscsi eh thread when sending
         * task management functions. This must be taken before the session
         * and recv lock.
         */
        struct mutex            eh_mutex;

        /* iSCSI session-wide sequencing */
        uint32_t                cmdsn;
        uint32_t                exp_cmdsn;
        uint32_t                max_cmdsn;

        /* This tracks the reqs queued into the initiator */
        uint32_t                queued_cmdsn;

        /* configuration */
        int                     abort_timeout;
        int                     lu_reset_timeout;
        int                     tgt_reset_timeout;
        int                     initial_r2t_en;
        unsigned short          max_r2t;
        int                     imm_data_en;
        unsigned                first_burst;
        unsigned                max_burst;
        int                     time2wait;
        int                     time2retain;
        int                     pdu_inorder_en;
        int                     dataseq_inorder_en;
        int                     erl;
        int                     fast_abort;
        int                     tpgt;
        char                    *username;
        char                    *username_in;
        char                    *password;
        char                    *password_in;
        char                    *targetname;
        char                    *targetalias;
        char                    *ifacename;
        char                    *initiatorname;
        char                    *boot_root;
        char                    *boot_nic;
        char                    *boot_target;
        char                    *portal_type;
        char                    *discovery_parent_type;
        uint16_t                discovery_parent_idx;
        uint16_t                def_taskmgmt_tmo;
        uint16_t                tsid;
        uint8_t                 auto_snd_tgt_disable;
        uint8_t                 discovery_sess;
        uint8_t                 chap_auth_en;
        uint8_t                 discovery_logout_en;
        uint8_t                 bidi_chap_en;
        uint8_t                 discovery_auth_optional;
        uint8_t                 isid[ISID_SIZE];

        /* control data */
        struct iscsi_transport  *tt;
        struct Scsi_Host        *host;
        struct iscsi_conn       *leadconn;      /* leading connection */
        /* Between the forward and the backward locks exists a strict locking
         * hierarchy. The mutual exclusion zone protected by the forward lock
         * can enclose the mutual exclusion zone protected by the backward lock
         * but not vice versa.
         */
        spinlock_t              frwd_lock;      /* protects session state, *
                                                 * cmdsn, queued_cmdsn     *
                                                 * session resources:      *
                                                 * - cmdpool kfifo_out ,   *
                                                 * - mgmtpool,             */
        spinlock_t              back_lock;      /* protects cmdsn_exp      *
                                                 * cmdsn_max,              *
                                                 * cmdpool kfifo_in        */
        int                     state;          /* session state           */
        int                     age;            /* counts session re-opens */

        int                     scsi_cmds_max;  /* max scsi commands */
        int                     cmds_max;       /* size of cmds array */
        struct iscsi_task       **cmds;         /* Original Cmds arr */
        struct iscsi_pool       cmdpool;        /* PDU's pool */
        void                    *dd_data;       /* LLD private data */
};

enum {
        ISCSI_HOST_SETUP,
        ISCSI_HOST_REMOVED,
};

struct iscsi_host {
        char                    *initiatorname;
        /* hw address or netdev iscsi connection is bound to */
        char                    *hwaddress;
        char                    *netdev;

        wait_queue_head_t       session_removal_wq;
        /* protects sessions and state */
        spinlock_t              lock;
        int                     num_sessions;
        int                     state;

        struct workqueue_struct *workq;
        char                    workq_name[20];
};

/*
 * scsi host template
 */
extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth,
                                    int reason);
extern int iscsi_eh_abort(struct scsi_cmnd *sc);
extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);

/*
 * iSCSI host helpers.
 */
#define iscsi_host_priv(_shost) \
        (shost_priv(_shost) + sizeof(struct iscsi_host))

extern int iscsi_host_set_param(struct Scsi_Host *shost,
                                enum iscsi_host_param param, char *buf,
                                int buflen);
extern int iscsi_host_get_param(struct Scsi_Host *shost,
                                enum iscsi_host_param param, char *buf);
extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
                                          int dd_data_size,
                                          bool xmit_can_sleep);
extern void iscsi_host_remove(struct Scsi_Host *shost);
extern void iscsi_host_free(struct Scsi_Host *shost);
extern int iscsi_target_alloc(struct scsi_target *starget);

/*
 * session management
 */
extern struct iscsi_cls_session *
iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
                    uint16_t, int, int, uint32_t, unsigned int);
extern void iscsi_session_teardown(struct iscsi_cls_session *);
extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
                           enum iscsi_param param, char *buf, int buflen);
extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
                                   enum iscsi_param param, char *buf);

#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)

/*
 * connection management
 */
extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
                                               int, uint32_t);
extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
extern int iscsi_conn_start(struct iscsi_cls_conn *);
extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
                           int);
extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
extern void iscsi_session_failure(struct iscsi_session *session,
                                  enum iscsi_err err);
extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
                                enum iscsi_param param, char *buf);
extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
                                     enum iscsi_param param, char *buf);
extern void iscsi_suspend_tx(struct iscsi_conn *conn);
extern void iscsi_suspend_queue(struct iscsi_conn *conn);
extern void iscsi_conn_queue_work(struct iscsi_conn *conn);

#define iscsi_conn_printk(prefix, _c, fmt, a...) \
        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
                              fmt, ##a)

/*
 * pdu and task processing
 */
extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
                                    struct iscsi_r2t_info *r2t,
                                    struct iscsi_data *hdr);
extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
                                char *, uint32_t);
extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
                              char *, int);
extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
                                char *, int);
extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
extern void iscsi_requeue_task(struct iscsi_task *task);
extern void iscsi_put_task(struct iscsi_task *task);
extern void __iscsi_put_task(struct iscsi_task *task);
extern void __iscsi_get_task(struct iscsi_task *task);
extern void iscsi_complete_scsi_task(struct iscsi_task *task,
                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);

/*
 * generic helpers
 */
extern void iscsi_pool_free(struct iscsi_pool *);
extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
extern int iscsi_switch_str_param(char **, char *);

/*
 * inline functions to deal with padding.
 */
static inline unsigned int
iscsi_padded(unsigned int len)
{
        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
}

static inline unsigned int
iscsi_padding(unsigned int len)
{
        len &= (ISCSI_PAD_LEN - 1);
        if (len)
                len = ISCSI_PAD_LEN - len;
        return len;
}

#endif

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