linux/include/scsi/libiscsi.h
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   1/*
   2 * iSCSI lib definitions
   3 *
   4 * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   5 * Copyright (C) 2004 - 2006 Mike Christie
   6 * Copyright (C) 2004 - 2005 Dmitry Yusupov
   7 * Copyright (C) 2004 - 2005 Alex Aizman
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22 */
  23#ifndef LIBISCSI_H
  24#define LIBISCSI_H
  25
  26#include <linux/types.h>
  27#include <linux/wait.h>
  28#include <linux/mutex.h>
  29#include <linux/timer.h>
  30#include <linux/workqueue.h>
  31#include <linux/kfifo.h>
  32#include <scsi/iscsi_proto.h>
  33#include <scsi/iscsi_if.h>
  34#include <scsi/scsi_transport_iscsi.h>
  35
  36struct scsi_transport_template;
  37struct scsi_host_template;
  38struct scsi_device;
  39struct Scsi_Host;
  40struct scsi_target;
  41struct scsi_cmnd;
  42struct socket;
  43struct iscsi_transport;
  44struct iscsi_cls_session;
  45struct iscsi_cls_conn;
  46struct iscsi_session;
  47struct iscsi_nopin;
  48struct device;
  49
  50#define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  51#define ISCSI_MGMT_CMDS_MAX     15
  52
  53#define ISCSI_DEF_CMD_PER_LUN   32
  54
  55/* Task Mgmt states */
  56enum {
  57        TMF_INITIAL,
  58        TMF_QUEUED,
  59        TMF_SUCCESS,
  60        TMF_FAILED,
  61        TMF_TIMEDOUT,
  62        TMF_NOT_FOUND,
  63};
  64
  65/* Connection suspend "bit" */
  66#define ISCSI_SUSPEND_BIT               1
  67
  68#define ISCSI_ITT_MASK                  0x1fff
  69#define ISCSI_TOTAL_CMDS_MAX            4096
  70/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  71#define ISCSI_TOTAL_CMDS_MIN            16
  72#define ISCSI_AGE_SHIFT                 28
  73#define ISCSI_AGE_MASK                  0xf
  74
  75#define ISCSI_ADDRESS_BUF_LEN           64
  76
  77enum {
  78        /* this is the maximum possible storage for AHSs */
  79        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  80                                sizeof(struct iscsi_rlength_ahdr),
  81        ISCSI_DIGEST_SIZE = sizeof(__u32),
  82};
  83
  84
  85enum {
  86        ISCSI_TASK_FREE,
  87        ISCSI_TASK_COMPLETED,
  88        ISCSI_TASK_PENDING,
  89        ISCSI_TASK_RUNNING,
  90        ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
  91        ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
  92        ISCSI_TASK_REQUEUE_SCSIQ,       /* qcmd requeueing to scsi-ml */
  93};
  94
  95struct iscsi_r2t_info {
  96        __be32                  ttt;            /* copied from R2T */
  97        __be32                  exp_statsn;     /* copied from R2T */
  98        uint32_t                data_length;    /* copied from R2T */
  99        uint32_t                data_offset;    /* copied from R2T */
 100        int                     data_count;     /* DATA-Out payload progress */
 101        int                     datasn;
 102        /* LLDs should set/update these values */
 103        int                     sent;           /* R2T sequence progress */
 104};
 105
 106struct iscsi_task {
 107        /*
 108         * Because LLDs allocate their hdr differently, this is a pointer
 109         * and length to that storage. It must be setup at session
 110         * creation time.
 111         */
 112        struct iscsi_hdr        *hdr;
 113        unsigned short          hdr_max;
 114        unsigned short          hdr_len;        /* accumulated size of hdr used */
 115        /* copied values in case we need to send tmfs */
 116        itt_t                   hdr_itt;
 117        __be32                  cmdsn;
 118        struct scsi_lun         lun;
 119
 120        int                     itt;            /* this ITT */
 121
 122        unsigned                imm_count;      /* imm-data (bytes)   */
 123        /* offset in unsolicited stream (bytes); */
 124        struct iscsi_r2t_info   unsol_r2t;
 125        char                    *data;          /* mgmt payload */
 126        unsigned                data_count;
 127        struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 128        struct iscsi_conn       *conn;          /* used connection    */
 129
 130        /* data processing tracking */
 131        unsigned long           last_xfer;
 132        unsigned long           last_timeout;
 133        bool                    have_checked_conn;
 134        /* state set/tested under session->lock */
 135        int                     state;
 136        atomic_t                refcount;
 137        struct list_head        running;        /* running cmd list */
 138        void                    *dd_data;       /* driver/transport data */
 139};
 140
 141static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 142{
 143        return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 144}
 145
 146static inline void* iscsi_next_hdr(struct iscsi_task *task)
 147{
 148        return (void*)task->hdr + task->hdr_len;
 149}
 150
 151/* Connection's states */
 152enum {
 153        ISCSI_CONN_INITIAL_STAGE,
 154        ISCSI_CONN_STARTED,
 155        ISCSI_CONN_STOPPED,
 156        ISCSI_CONN_CLEANUP_WAIT,
 157};
 158
 159struct iscsi_conn {
 160        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 161        void                    *dd_data;       /* iscsi_transport data */
 162        struct iscsi_session    *session;       /* parent session */
 163        /*
 164         * conn_stop() flag: stop to recover, stop to terminate
 165         */
 166        int                     stop_stage;
 167        struct timer_list       transport_timer;
 168        unsigned long           last_recv;
 169        unsigned long           last_ping;
 170        int                     ping_timeout;
 171        int                     recv_timeout;
 172        struct iscsi_task       *ping_task;
 173
 174        /* iSCSI connection-wide sequencing */
 175        uint32_t                exp_statsn;
 176
 177        /* control data */
 178        int                     id;             /* CID */
 179        int                     c_stage;        /* connection state */
 180        /*
 181         * Preallocated buffer for pdus that have data but do not
 182         * originate from scsi-ml. We never have two pdus using the
 183         * buffer at the same time. It is only allocated to
 184         * the default max recv size because the pdus we support
 185         * should always fit in this buffer
 186         */
 187        char                    *data;
 188        struct iscsi_task       *login_task;    /* mtask used for login/text */
 189        struct iscsi_task       *task;          /* xmit task in progress */
 190
 191        /* xmit */
 192        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 193        struct list_head        cmdqueue;       /* data-path cmd queue */
 194        struct list_head        requeue;        /* tasks needing another run */
 195        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 196        unsigned long           suspend_tx;     /* suspend Tx */
 197        unsigned long           suspend_rx;     /* suspend Rx */
 198
 199        /* abort */
 200        wait_queue_head_t       ehwait;         /* used in eh_abort() */
 201        struct iscsi_tm         tmhdr;
 202        struct timer_list       tmf_timer;
 203        int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 204
 205        /* negotiated params */
 206        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 207        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 208        int                     hdrdgst_en;
 209        int                     datadgst_en;
 210        int                     ifmarker_en;
 211        int                     ofmarker_en;
 212        /* values userspace uses to id a conn */
 213        int                     persistent_port;
 214        char                    *persistent_address;
 215
 216        /* MIB-statistics */
 217        uint64_t                txdata_octets;
 218        uint64_t                rxdata_octets;
 219        uint32_t                scsicmd_pdus_cnt;
 220        uint32_t                dataout_pdus_cnt;
 221        uint32_t                scsirsp_pdus_cnt;
 222        uint32_t                datain_pdus_cnt;
 223        uint32_t                r2t_pdus_cnt;
 224        uint32_t                tmfcmd_pdus_cnt;
 225        int32_t                 tmfrsp_pdus_cnt;
 226
 227        /* custom statistics */
 228        uint32_t                eh_abort_cnt;
 229        uint32_t                fmr_unalign_cnt;
 230};
 231
 232struct iscsi_pool {
 233        struct kfifo            queue;          /* FIFO Queue */
 234        void                    **pool;         /* Pool of elements */
 235        int                     max;            /* Max number of elements */
 236};
 237
 238/* Session's states */
 239enum {
 240        ISCSI_STATE_FREE = 1,
 241        ISCSI_STATE_LOGGED_IN,
 242        ISCSI_STATE_FAILED,
 243        ISCSI_STATE_TERMINATE,
 244        ISCSI_STATE_IN_RECOVERY,
 245        ISCSI_STATE_RECOVERY_FAILED,
 246        ISCSI_STATE_LOGGING_OUT,
 247};
 248
 249struct iscsi_session {
 250        struct iscsi_cls_session *cls_session;
 251        /*
 252         * Syncs up the scsi eh thread with the iscsi eh thread when sending
 253         * task management functions. This must be taken before the session
 254         * and recv lock.
 255         */
 256        struct mutex            eh_mutex;
 257
 258        /* iSCSI session-wide sequencing */
 259        uint32_t                cmdsn;
 260        uint32_t                exp_cmdsn;
 261        uint32_t                max_cmdsn;
 262
 263        /* This tracks the reqs queued into the initiator */
 264        uint32_t                queued_cmdsn;
 265
 266        /* configuration */
 267        int                     abort_timeout;
 268        int                     lu_reset_timeout;
 269        int                     tgt_reset_timeout;
 270        int                     initial_r2t_en;
 271        unsigned short          max_r2t;
 272        int                     imm_data_en;
 273        unsigned                first_burst;
 274        unsigned                max_burst;
 275        int                     time2wait;
 276        int                     time2retain;
 277        int                     pdu_inorder_en;
 278        int                     dataseq_inorder_en;
 279        int                     erl;
 280        int                     fast_abort;
 281        int                     tpgt;
 282        char                    *username;
 283        char                    *username_in;
 284        char                    *password;
 285        char                    *password_in;
 286        char                    *targetname;
 287        char                    *targetalias;
 288        char                    *ifacename;
 289        char                    *initiatorname;
 290        /* control data */
 291        struct iscsi_transport  *tt;
 292        struct Scsi_Host        *host;
 293        struct iscsi_conn       *leadconn;      /* leading connection */
 294        spinlock_t              lock;           /* protects session state, *
 295                                                 * sequence numbers,       *
 296                                                 * session resources:      *
 297                                                 * - cmdpool,              *
 298                                                 * - mgmtpool,             *
 299                                                 * - r2tpool               */
 300        int                     state;          /* session state           */
 301        int                     age;            /* counts session re-opens */
 302
 303        int                     scsi_cmds_max;  /* max scsi commands */
 304        int                     cmds_max;       /* size of cmds array */
 305        struct iscsi_task       **cmds;         /* Original Cmds arr */
 306        struct iscsi_pool       cmdpool;        /* PDU's pool */
 307        void                    *dd_data;       /* LLD private data */
 308};
 309
 310enum {
 311        ISCSI_HOST_SETUP,
 312        ISCSI_HOST_REMOVED,
 313};
 314
 315struct iscsi_host {
 316        char                    *initiatorname;
 317        /* hw address or netdev iscsi connection is bound to */
 318        char                    *hwaddress;
 319        char                    *netdev;
 320
 321        wait_queue_head_t       session_removal_wq;
 322        /* protects sessions and state */
 323        spinlock_t              lock;
 324        int                     num_sessions;
 325        int                     state;
 326
 327        struct workqueue_struct *workq;
 328        char                    workq_name[20];
 329};
 330
 331/*
 332 * scsi host template
 333 */
 334extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth,
 335                                    int reason);
 336extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 337extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 338extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 339extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 340extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 341
 342/*
 343 * iSCSI host helpers.
 344 */
 345#define iscsi_host_priv(_shost) \
 346        (shost_priv(_shost) + sizeof(struct iscsi_host))
 347
 348extern int iscsi_host_set_param(struct Scsi_Host *shost,
 349                                enum iscsi_host_param param, char *buf,
 350                                int buflen);
 351extern int iscsi_host_get_param(struct Scsi_Host *shost,
 352                                enum iscsi_host_param param, char *buf);
 353extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 354extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 355                                          int dd_data_size,
 356                                          bool xmit_can_sleep);
 357extern void iscsi_host_remove(struct Scsi_Host *shost);
 358extern void iscsi_host_free(struct Scsi_Host *shost);
 359extern int iscsi_target_alloc(struct scsi_target *starget);
 360
 361/*
 362 * session management
 363 */
 364extern struct iscsi_cls_session *
 365iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 366                    uint16_t, int, int, uint32_t, unsigned int);
 367extern void iscsi_session_teardown(struct iscsi_cls_session *);
 368extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 369extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 370                           enum iscsi_param param, char *buf, int buflen);
 371extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 372                                   enum iscsi_param param, char *buf);
 373
 374#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 375        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 376
 377/*
 378 * connection management
 379 */
 380extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 381                                               int, uint32_t);
 382extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 383extern int iscsi_conn_start(struct iscsi_cls_conn *);
 384extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 385extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 386                           int);
 387extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 388extern void iscsi_session_failure(struct iscsi_session *session,
 389                                  enum iscsi_err err);
 390extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 391                                enum iscsi_param param, char *buf);
 392extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 393                                     enum iscsi_param param, char *buf);
 394extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 395extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 396extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 397
 398#define iscsi_conn_printk(prefix, _c, fmt, a...) \
 399        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 400                              fmt, ##a)
 401
 402/*
 403 * pdu and task processing
 404 */
 405extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 406extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 407                                    struct iscsi_r2t_info *r2t,
 408                                    struct iscsi_data *hdr);
 409extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 410                                char *, uint32_t);
 411extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 412                              char *, int);
 413extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 414                                char *, int);
 415extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 416extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 417extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 418extern void iscsi_requeue_task(struct iscsi_task *task);
 419extern void iscsi_put_task(struct iscsi_task *task);
 420extern void __iscsi_put_task(struct iscsi_task *task);
 421extern void __iscsi_get_task(struct iscsi_task *task);
 422extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 423                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);
 424
 425/*
 426 * generic helpers
 427 */
 428extern void iscsi_pool_free(struct iscsi_pool *);
 429extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 430
 431/*
 432 * inline functions to deal with padding.
 433 */
 434static inline unsigned int
 435iscsi_padded(unsigned int len)
 436{
 437        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 438}
 439
 440static inline unsigned int
 441iscsi_padding(unsigned int len)
 442{
 443        len &= (ISCSI_PAD_LEN - 1);
 444        if (len)
 445                len = ISCSI_PAD_LEN - len;
 446        return len;
 447}
 448
 449#endif
 450
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