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 <linux/refcount.h>
  33#include <scsi/iscsi_proto.h>
  34#include <scsi/iscsi_if.h>
  35#include <scsi/scsi_transport_iscsi.h>
  36
  37struct scsi_transport_template;
  38struct scsi_host_template;
  39struct scsi_device;
  40struct Scsi_Host;
  41struct scsi_target;
  42struct scsi_cmnd;
  43struct socket;
  44struct iscsi_transport;
  45struct iscsi_cls_session;
  46struct iscsi_cls_conn;
  47struct iscsi_session;
  48struct iscsi_nopin;
  49struct device;
  50
  51#define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  52#define ISCSI_MGMT_CMDS_MAX     15
  53
  54#define ISCSI_DEF_CMD_PER_LUN   32
  55
  56/* Task Mgmt states */
  57enum {
  58        TMF_INITIAL,
  59        TMF_QUEUED,
  60        TMF_SUCCESS,
  61        TMF_FAILED,
  62        TMF_TIMEDOUT,
  63        TMF_NOT_FOUND,
  64};
  65
  66#define ISID_SIZE                       6
  67
  68/* Connection suspend "bit" */
  69#define ISCSI_SUSPEND_BIT               1
  70
  71#define ISCSI_ITT_MASK                  0x1fff
  72#define ISCSI_TOTAL_CMDS_MAX            4096
  73/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  74#define ISCSI_TOTAL_CMDS_MIN            16
  75#define ISCSI_AGE_SHIFT                 28
  76#define ISCSI_AGE_MASK                  0xf
  77
  78#define ISCSI_ADDRESS_BUF_LEN           64
  79
  80enum {
  81        /* this is the maximum possible storage for AHSs */
  82        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  83                                sizeof(struct iscsi_rlength_ahdr),
  84        ISCSI_DIGEST_SIZE = sizeof(__u32),
  85};
  86
  87
  88enum {
  89        ISCSI_TASK_FREE,
  90        ISCSI_TASK_COMPLETED,
  91        ISCSI_TASK_PENDING,
  92        ISCSI_TASK_RUNNING,
  93        ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
  94        ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
  95        ISCSI_TASK_REQUEUE_SCSIQ,       /* qcmd requeueing to scsi-ml */
  96};
  97
  98struct iscsi_r2t_info {
  99        __be32                  ttt;            /* copied from R2T */
 100        __be32                  exp_statsn;     /* copied from R2T */
 101        uint32_t                data_length;    /* copied from R2T */
 102        uint32_t                data_offset;    /* copied from R2T */
 103        int                     data_count;     /* DATA-Out payload progress */
 104        int                     datasn;
 105        /* LLDs should set/update these values */
 106        int                     sent;           /* R2T sequence progress */
 107};
 108
 109struct iscsi_task {
 110        /*
 111         * Because LLDs allocate their hdr differently, this is a pointer
 112         * and length to that storage. It must be setup at session
 113         * creation time.
 114         */
 115        struct iscsi_hdr        *hdr;
 116        unsigned short          hdr_max;
 117        unsigned short          hdr_len;        /* accumulated size of hdr used */
 118        /* copied values in case we need to send tmfs */
 119        itt_t                   hdr_itt;
 120        __be32                  cmdsn;
 121        struct scsi_lun         lun;
 122
 123        int                     itt;            /* this ITT */
 124
 125        unsigned                imm_count;      /* imm-data (bytes)   */
 126        /* offset in unsolicited stream (bytes); */
 127        struct iscsi_r2t_info   unsol_r2t;
 128        char                    *data;          /* mgmt payload */
 129        unsigned                data_count;
 130        struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 131        struct iscsi_conn       *conn;          /* used connection    */
 132
 133        /* data processing tracking */
 134        unsigned long           last_xfer;
 135        unsigned long           last_timeout;
 136        bool                    have_checked_conn;
 137
 138        /* T10 protection information */
 139        bool                    protected;
 140
 141        /* state set/tested under session->lock */
 142        int                     state;
 143        refcount_t              refcount;
 144        struct list_head        running;        /* running cmd list */
 145        void                    *dd_data;       /* driver/transport data */
 146};
 147
 148static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 149{
 150        return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 151}
 152
 153static inline void* iscsi_next_hdr(struct iscsi_task *task)
 154{
 155        return (void*)task->hdr + task->hdr_len;
 156}
 157
 158/* Connection's states */
 159enum {
 160        ISCSI_CONN_INITIAL_STAGE,
 161        ISCSI_CONN_STARTED,
 162        ISCSI_CONN_STOPPED,
 163        ISCSI_CONN_CLEANUP_WAIT,
 164};
 165
 166struct iscsi_conn {
 167        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 168        void                    *dd_data;       /* iscsi_transport data */
 169        struct iscsi_session    *session;       /* parent session */
 170        /*
 171         * conn_stop() flag: stop to recover, stop to terminate
 172         */
 173        int                     stop_stage;
 174        struct timer_list       transport_timer;
 175        unsigned long           last_recv;
 176        unsigned long           last_ping;
 177        int                     ping_timeout;
 178        int                     recv_timeout;
 179        struct iscsi_task       *ping_task;
 180
 181        /* iSCSI connection-wide sequencing */
 182        uint32_t                exp_statsn;
 183        uint32_t                statsn;
 184
 185        /* control data */
 186        int                     id;             /* CID */
 187        int                     c_stage;        /* connection state */
 188        /*
 189         * Preallocated buffer for pdus that have data but do not
 190         * originate from scsi-ml. We never have two pdus using the
 191         * buffer at the same time. It is only allocated to
 192         * the default max recv size because the pdus we support
 193         * should always fit in this buffer
 194         */
 195        char                    *data;
 196        struct iscsi_task       *login_task;    /* mtask used for login/text */
 197        struct iscsi_task       *task;          /* xmit task in progress */
 198
 199        /* xmit */
 200        spinlock_t              taskqueuelock;  /* protects the next three lists */
 201        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 202        struct list_head        cmdqueue;       /* data-path cmd queue */
 203        struct list_head        requeue;        /* tasks needing another run */
 204        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 205        unsigned long           suspend_tx;     /* suspend Tx */
 206        unsigned long           suspend_rx;     /* suspend Rx */
 207
 208        /* abort */
 209        wait_queue_head_t       ehwait;         /* used in eh_abort() */
 210        struct iscsi_tm         tmhdr;
 211        struct timer_list       tmf_timer;
 212        int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 213
 214        /* negotiated params */
 215        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 216        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 217        int                     hdrdgst_en;
 218        int                     datadgst_en;
 219        int                     ifmarker_en;
 220        int                     ofmarker_en;
 221        /* values userspace uses to id a conn */
 222        int                     persistent_port;
 223        char                    *persistent_address;
 224
 225        unsigned                max_segment_size;
 226        unsigned                tcp_xmit_wsf;
 227        unsigned                tcp_recv_wsf;
 228        uint16_t                keepalive_tmo;
 229        uint16_t                local_port;
 230        uint8_t                 tcp_timestamp_stat;
 231        uint8_t                 tcp_nagle_disable;
 232        uint8_t                 tcp_wsf_disable;
 233        uint8_t                 tcp_timer_scale;
 234        uint8_t                 tcp_timestamp_en;
 235        uint8_t                 fragment_disable;
 236        uint8_t                 ipv4_tos;
 237        uint8_t                 ipv6_traffic_class;
 238        uint8_t                 ipv6_flow_label;
 239        uint8_t                 is_fw_assigned_ipv6;
 240        char                    *local_ipaddr;
 241
 242        /* MIB-statistics */
 243        uint64_t                txdata_octets;
 244        uint64_t                rxdata_octets;
 245        uint32_t                scsicmd_pdus_cnt;
 246        uint32_t                dataout_pdus_cnt;
 247        uint32_t                scsirsp_pdus_cnt;
 248        uint32_t                datain_pdus_cnt;
 249        uint32_t                r2t_pdus_cnt;
 250        uint32_t                tmfcmd_pdus_cnt;
 251        int32_t                 tmfrsp_pdus_cnt;
 252
 253        /* custom statistics */
 254        uint32_t                eh_abort_cnt;
 255        uint32_t                fmr_unalign_cnt;
 256};
 257
 258struct iscsi_pool {
 259        struct kfifo            queue;          /* FIFO Queue */
 260        void                    **pool;         /* Pool of elements */
 261        int                     max;            /* Max number of elements */
 262};
 263
 264/* Session's states */
 265enum {
 266        ISCSI_STATE_FREE = 1,
 267        ISCSI_STATE_LOGGED_IN,
 268        ISCSI_STATE_FAILED,
 269        ISCSI_STATE_TERMINATE,
 270        ISCSI_STATE_IN_RECOVERY,
 271        ISCSI_STATE_RECOVERY_FAILED,
 272        ISCSI_STATE_LOGGING_OUT,
 273};
 274
 275struct iscsi_session {
 276        struct iscsi_cls_session *cls_session;
 277        /*
 278         * Syncs up the scsi eh thread with the iscsi eh thread when sending
 279         * task management functions. This must be taken before the session
 280         * and recv lock.
 281         */
 282        struct mutex            eh_mutex;
 283
 284        /* iSCSI session-wide sequencing */
 285        uint32_t                cmdsn;
 286        uint32_t                exp_cmdsn;
 287        uint32_t                max_cmdsn;
 288
 289        /* This tracks the reqs queued into the initiator */
 290        uint32_t                queued_cmdsn;
 291
 292        /* configuration */
 293        int                     abort_timeout;
 294        int                     lu_reset_timeout;
 295        int                     tgt_reset_timeout;
 296        int                     initial_r2t_en;
 297        unsigned short          max_r2t;
 298        int                     imm_data_en;
 299        unsigned                first_burst;
 300        unsigned                max_burst;
 301        int                     time2wait;
 302        int                     time2retain;
 303        int                     pdu_inorder_en;
 304        int                     dataseq_inorder_en;
 305        int                     erl;
 306        int                     fast_abort;
 307        int                     tpgt;
 308        char                    *username;
 309        char                    *username_in;
 310        char                    *password;
 311        char                    *password_in;
 312        char                    *targetname;
 313        char                    *targetalias;
 314        char                    *ifacename;
 315        char                    *initiatorname;
 316        char                    *boot_root;
 317        char                    *boot_nic;
 318        char                    *boot_target;
 319        char                    *portal_type;
 320        char                    *discovery_parent_type;
 321        uint16_t                discovery_parent_idx;
 322        uint16_t                def_taskmgmt_tmo;
 323        uint16_t                tsid;
 324        uint8_t                 auto_snd_tgt_disable;
 325        uint8_t                 discovery_sess;
 326        uint8_t                 chap_auth_en;
 327        uint8_t                 discovery_logout_en;
 328        uint8_t                 bidi_chap_en;
 329        uint8_t                 discovery_auth_optional;
 330        uint8_t                 isid[ISID_SIZE];
 331
 332        /* control data */
 333        struct iscsi_transport  *tt;
 334        struct Scsi_Host        *host;
 335        struct iscsi_conn       *leadconn;      /* leading connection */
 336        /* Between the forward and the backward locks exists a strict locking
 337         * hierarchy. The mutual exclusion zone protected by the forward lock
 338         * can enclose the mutual exclusion zone protected by the backward lock
 339         * but not vice versa.
 340         */
 341        spinlock_t              frwd_lock;      /* protects session state, *
 342                                                 * cmdsn, queued_cmdsn     *
 343                                                 * session resources:      *
 344                                                 * - cmdpool kfifo_out ,   *
 345                                                 * - mgmtpool,             */
 346        spinlock_t              back_lock;      /* protects cmdsn_exp      *
 347                                                 * cmdsn_max,              *
 348                                                 * cmdpool kfifo_in        */
 349        int                     state;          /* session state           */
 350        int                     age;            /* counts session re-opens */
 351
 352        int                     scsi_cmds_max;  /* max scsi commands */
 353        int                     cmds_max;       /* size of cmds array */
 354        struct iscsi_task       **cmds;         /* Original Cmds arr */
 355        struct iscsi_pool       cmdpool;        /* PDU's pool */
 356        void                    *dd_data;       /* LLD private data */
 357};
 358
 359enum {
 360        ISCSI_HOST_SETUP,
 361        ISCSI_HOST_REMOVED,
 362};
 363
 364struct iscsi_host {
 365        char                    *initiatorname;
 366        /* hw address or netdev iscsi connection is bound to */
 367        char                    *hwaddress;
 368        char                    *netdev;
 369
 370        wait_queue_head_t       session_removal_wq;
 371        /* protects sessions and state */
 372        spinlock_t              lock;
 373        int                     num_sessions;
 374        int                     state;
 375
 376        struct workqueue_struct *workq;
 377        char                    workq_name[20];
 378};
 379
 380/*
 381 * scsi host template
 382 */
 383extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 384extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 385extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 386extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 387extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 388extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
 389
 390/*
 391 * iSCSI host helpers.
 392 */
 393#define iscsi_host_priv(_shost) \
 394        (shost_priv(_shost) + sizeof(struct iscsi_host))
 395
 396extern int iscsi_host_set_param(struct Scsi_Host *shost,
 397                                enum iscsi_host_param param, char *buf,
 398                                int buflen);
 399extern int iscsi_host_get_param(struct Scsi_Host *shost,
 400                                enum iscsi_host_param param, char *buf);
 401extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 402extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 403                                          int dd_data_size,
 404                                          bool xmit_can_sleep);
 405extern void iscsi_host_remove(struct Scsi_Host *shost);
 406extern void iscsi_host_free(struct Scsi_Host *shost);
 407extern int iscsi_target_alloc(struct scsi_target *starget);
 408
 409/*
 410 * session management
 411 */
 412extern struct iscsi_cls_session *
 413iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 414                    uint16_t, int, int, uint32_t, unsigned int);
 415extern void iscsi_session_teardown(struct iscsi_cls_session *);
 416extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 417extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 418                           enum iscsi_param param, char *buf, int buflen);
 419extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 420                                   enum iscsi_param param, char *buf);
 421
 422#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 423        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 424
 425/*
 426 * connection management
 427 */
 428extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 429                                               int, uint32_t);
 430extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 431extern int iscsi_conn_start(struct iscsi_cls_conn *);
 432extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 433extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 434                           int);
 435extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 436extern void iscsi_session_failure(struct iscsi_session *session,
 437                                  enum iscsi_err err);
 438extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 439                                enum iscsi_param param, char *buf);
 440extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 441                                     enum iscsi_param param, char *buf);
 442extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 443extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 444extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 445
 446#define iscsi_conn_printk(prefix, _c, fmt, a...) \
 447        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 448                              fmt, ##a)
 449
 450/*
 451 * pdu and task processing
 452 */
 453extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 454extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 455                                    struct iscsi_r2t_info *r2t,
 456                                    struct iscsi_data *hdr);
 457extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 458                                char *, uint32_t);
 459extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 460                              char *, int);
 461extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 462                                char *, int);
 463extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 464extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 465extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 466extern void iscsi_requeue_task(struct iscsi_task *task);
 467extern void iscsi_put_task(struct iscsi_task *task);
 468extern void __iscsi_put_task(struct iscsi_task *task);
 469extern void __iscsi_get_task(struct iscsi_task *task);
 470extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 471                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);
 472
 473/*
 474 * generic helpers
 475 */
 476extern void iscsi_pool_free(struct iscsi_pool *);
 477extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 478extern int iscsi_switch_str_param(char **, char *);
 479
 480/*
 481 * inline functions to deal with padding.
 482 */
 483static inline unsigned int
 484iscsi_padded(unsigned int len)
 485{
 486        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 487}
 488
 489static inline unsigned int
 490iscsi_padding(unsigned int len)
 491{
 492        len &= (ISCSI_PAD_LEN - 1);
 493        if (len)
 494                len = ISCSI_PAD_LEN - len;
 495        return len;
 496}
 497
 498#endif
 499
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