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 <scsi/iscsi_proto.h>
  32#include <scsi/iscsi_if.h>
  33#include <scsi/scsi_transport_iscsi.h>
  34
  35struct scsi_transport_template;
  36struct scsi_host_template;
  37struct scsi_device;
  38struct Scsi_Host;
  39struct scsi_target;
  40struct scsi_cmnd;
  41struct socket;
  42struct iscsi_transport;
  43struct iscsi_cls_session;
  44struct iscsi_cls_conn;
  45struct iscsi_session;
  46struct iscsi_nopin;
  47struct device;
  48
  49#define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  50#define ISCSI_MGMT_CMDS_MAX     15
  51
  52#define ISCSI_DEF_CMD_PER_LUN   32
  53
  54/* Task Mgmt states */
  55enum {
  56        TMF_INITIAL,
  57        TMF_QUEUED,
  58        TMF_SUCCESS,
  59        TMF_FAILED,
  60        TMF_TIMEDOUT,
  61        TMF_NOT_FOUND,
  62};
  63
  64/* Connection suspend "bit" */
  65#define ISCSI_SUSPEND_BIT               1
  66
  67#define ISCSI_ITT_MASK                  0x1fff
  68#define ISCSI_TOTAL_CMDS_MAX            4096
  69/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  70#define ISCSI_TOTAL_CMDS_MIN            16
  71#define ISCSI_AGE_SHIFT                 28
  72#define ISCSI_AGE_MASK                  0xf
  73
  74#define ISCSI_ADDRESS_BUF_LEN           64
  75
  76enum {
  77        /* this is the maximum possible storage for AHSs */
  78        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  79                                sizeof(struct iscsi_rlength_ahdr),
  80        ISCSI_DIGEST_SIZE = sizeof(__u32),
  81};
  82
  83
  84enum {
  85        ISCSI_TASK_FREE,
  86        ISCSI_TASK_COMPLETED,
  87        ISCSI_TASK_PENDING,
  88        ISCSI_TASK_RUNNING,
  89        ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
  90        ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
  91};
  92
  93struct iscsi_r2t_info {
  94        __be32                  ttt;            /* copied from R2T */
  95        __be32                  exp_statsn;     /* copied from R2T */
  96        uint32_t                data_length;    /* copied from R2T */
  97        uint32_t                data_offset;    /* copied from R2T */
  98        int                     data_count;     /* DATA-Out payload progress */
  99        int                     datasn;
 100        /* LLDs should set/update these values */
 101        int                     sent;           /* R2T sequence progress */
 102};
 103
 104struct iscsi_task {
 105        /*
 106         * Because LLDs allocate their hdr differently, this is a pointer
 107         * and length to that storage. It must be setup at session
 108         * creation time.
 109         */
 110        struct iscsi_hdr        *hdr;
 111        unsigned short          hdr_max;
 112        unsigned short          hdr_len;        /* accumulated size of hdr used */
 113        /* copied values in case we need to send tmfs */
 114        itt_t                   hdr_itt;
 115        __be32                  cmdsn;
 116        uint8_t                 lun[8];
 117
 118        int                     itt;            /* this ITT */
 119
 120        unsigned                imm_count;      /* imm-data (bytes)   */
 121        /* offset in unsolicited stream (bytes); */
 122        struct iscsi_r2t_info   unsol_r2t;
 123        char                    *data;          /* mgmt payload */
 124        unsigned                data_count;
 125        struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 126        struct iscsi_conn       *conn;          /* used connection    */
 127
 128        /* data processing tracking */
 129        unsigned long           last_xfer;
 130        unsigned long           last_timeout;
 131        bool                    have_checked_conn;
 132        /* state set/tested under session->lock */
 133        int                     state;
 134        atomic_t                refcount;
 135        struct list_head        running;        /* running cmd list */
 136        void                    *dd_data;       /* driver/transport data */
 137};
 138
 139static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 140{
 141        return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 142}
 143
 144static inline void* iscsi_next_hdr(struct iscsi_task *task)
 145{
 146        return (void*)task->hdr + task->hdr_len;
 147}
 148
 149/* Connection's states */
 150enum {
 151        ISCSI_CONN_INITIAL_STAGE,
 152        ISCSI_CONN_STARTED,
 153        ISCSI_CONN_STOPPED,
 154        ISCSI_CONN_CLEANUP_WAIT,
 155};
 156
 157struct iscsi_conn {
 158        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 159        void                    *dd_data;       /* iscsi_transport data */
 160        struct iscsi_session    *session;       /* parent session */
 161        /*
 162         * conn_stop() flag: stop to recover, stop to terminate
 163         */
 164        int                     stop_stage;
 165        struct timer_list       transport_timer;
 166        unsigned long           last_recv;
 167        unsigned long           last_ping;
 168        int                     ping_timeout;
 169        int                     recv_timeout;
 170        struct iscsi_task       *ping_task;
 171
 172        /* iSCSI connection-wide sequencing */
 173        uint32_t                exp_statsn;
 174
 175        /* control data */
 176        int                     id;             /* CID */
 177        int                     c_stage;        /* connection state */
 178        /*
 179         * Preallocated buffer for pdus that have data but do not
 180         * originate from scsi-ml. We never have two pdus using the
 181         * buffer at the same time. It is only allocated to
 182         * the default max recv size because the pdus we support
 183         * should always fit in this buffer
 184         */
 185        char                    *data;
 186        struct iscsi_task       *login_task;    /* mtask used for login/text */
 187        struct iscsi_task       *task;          /* xmit task in progress */
 188
 189        /* xmit */
 190        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 191        struct list_head        cmdqueue;       /* data-path cmd queue */
 192        struct list_head        requeue;        /* tasks needing another run */
 193        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 194        unsigned long           suspend_tx;     /* suspend Tx */
 195        unsigned long           suspend_rx;     /* suspend Rx */
 196
 197        /* abort */
 198        wait_queue_head_t       ehwait;         /* used in eh_abort() */
 199        struct iscsi_tm         tmhdr;
 200        struct timer_list       tmf_timer;
 201        int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 202
 203        /* negotiated params */
 204        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 205        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 206        int                     hdrdgst_en;
 207        int                     datadgst_en;
 208        int                     ifmarker_en;
 209        int                     ofmarker_en;
 210        /* values userspace uses to id a conn */
 211        int                     persistent_port;
 212        char                    *persistent_address;
 213        /* remote portal currently connected to */
 214        int                     portal_port;
 215        char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 216
 217        /* MIB-statistics */
 218        uint64_t                txdata_octets;
 219        uint64_t                rxdata_octets;
 220        uint32_t                scsicmd_pdus_cnt;
 221        uint32_t                dataout_pdus_cnt;
 222        uint32_t                scsirsp_pdus_cnt;
 223        uint32_t                datain_pdus_cnt;
 224        uint32_t                r2t_pdus_cnt;
 225        uint32_t                tmfcmd_pdus_cnt;
 226        int32_t                 tmfrsp_pdus_cnt;
 227
 228        /* custom statistics */
 229        uint32_t                eh_abort_cnt;
 230        uint32_t                fmr_unalign_cnt;
 231};
 232
 233struct iscsi_pool {
 234        struct kfifo            *queue;         /* FIFO Queue */
 235        void                    **pool;         /* Pool of elements */
 236        int                     max;            /* Max number of elements */
 237};
 238
 239/* Session's states */
 240enum {
 241        ISCSI_STATE_FREE = 1,
 242        ISCSI_STATE_LOGGED_IN,
 243        ISCSI_STATE_FAILED,
 244        ISCSI_STATE_TERMINATE,
 245        ISCSI_STATE_IN_RECOVERY,
 246        ISCSI_STATE_RECOVERY_FAILED,
 247        ISCSI_STATE_LOGGING_OUT,
 248};
 249
 250struct iscsi_session {
 251        struct iscsi_cls_session *cls_session;
 252        /*
 253         * Syncs up the scsi eh thread with the iscsi eh thread when sending
 254         * task management functions. This must be taken before the session
 255         * and recv lock.
 256         */
 257        struct mutex            eh_mutex;
 258
 259        /* iSCSI session-wide sequencing */
 260        uint32_t                cmdsn;
 261        uint32_t                exp_cmdsn;
 262        uint32_t                max_cmdsn;
 263
 264        /* This tracks the reqs queued into the initiator */
 265        uint32_t                queued_cmdsn;
 266
 267        /* configuration */
 268        int                     abort_timeout;
 269        int                     lu_reset_timeout;
 270        int                     initial_r2t_en;
 271        unsigned                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                    *ifacename;
 288        char                    *initiatorname;
 289        /* control data */
 290        struct iscsi_transport  *tt;
 291        struct Scsi_Host        *host;
 292        struct iscsi_conn       *leadconn;      /* leading connection */
 293        spinlock_t              lock;           /* protects session state, *
 294                                                 * sequence numbers,       *
 295                                                 * session resources:      *
 296                                                 * - cmdpool,              *
 297                                                 * - mgmtpool,             *
 298                                                 * - r2tpool               */
 299        int                     state;          /* session state           */
 300        int                     age;            /* counts session re-opens */
 301
 302        int                     scsi_cmds_max;  /* max scsi commands */
 303        int                     cmds_max;       /* size of cmds array */
 304        struct iscsi_task       **cmds;         /* Original Cmds arr */
 305        struct iscsi_pool       cmdpool;        /* PDU's pool */
 306        void                    *dd_data;       /* LLD private data */
 307};
 308
 309enum {
 310        ISCSI_HOST_SETUP,
 311        ISCSI_HOST_REMOVED,
 312};
 313
 314struct iscsi_host {
 315        char                    *initiatorname;
 316        /* hw address or netdev iscsi connection is bound to */
 317        char                    *hwaddress;
 318        char                    *netdev;
 319        /* local address */
 320        int                     local_port;
 321        char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 322
 323        wait_queue_head_t       session_removal_wq;
 324        /* protects sessions and state */
 325        spinlock_t              lock;
 326        int                     num_sessions;
 327        int                     state;
 328
 329        struct workqueue_struct *workq;
 330        char                    workq_name[20];
 331};
 332
 333/*
 334 * scsi host template
 335 */
 336extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 337extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 338extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 339extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 340extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 341                              void (*done)(struct scsi_cmnd *));
 342
 343/*
 344 * iSCSI host helpers.
 345 */
 346#define iscsi_host_priv(_shost) \
 347        (shost_priv(_shost) + sizeof(struct iscsi_host))
 348
 349extern int iscsi_host_set_param(struct Scsi_Host *shost,
 350                                enum iscsi_host_param param, char *buf,
 351                                int buflen);
 352extern int iscsi_host_get_param(struct Scsi_Host *shost,
 353                                enum iscsi_host_param param, char *buf);
 354extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 355extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 356                                          int dd_data_size,
 357                                          bool xmit_can_sleep);
 358extern void iscsi_host_remove(struct Scsi_Host *shost);
 359extern void iscsi_host_free(struct Scsi_Host *shost);
 360extern int iscsi_target_alloc(struct scsi_target *starget);
 361
 362/*
 363 * session management
 364 */
 365extern struct iscsi_cls_session *
 366iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 367                    uint16_t, int, int, uint32_t, unsigned int);
 368extern void iscsi_session_teardown(struct iscsi_cls_session *);
 369extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 370extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 371                           enum iscsi_param param, char *buf, int buflen);
 372extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 373                                   enum iscsi_param param, char *buf);
 374
 375#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 376        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 377
 378/*
 379 * connection management
 380 */
 381extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 382                                               int, uint32_t);
 383extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 384extern int iscsi_conn_start(struct iscsi_cls_conn *);
 385extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 386extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 387                           int);
 388extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 389extern void iscsi_session_failure(struct iscsi_session *session,
 390                                  enum iscsi_err err);
 391extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 392                                enum iscsi_param param, char *buf);
 393extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 394extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 395extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 396
 397#define iscsi_conn_printk(prefix, _c, fmt, a...) \
 398        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 399                              fmt, ##a)
 400
 401/*
 402 * pdu and task processing
 403 */
 404extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 405extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 406                                    struct iscsi_r2t_info *r2t,
 407                                    struct iscsi_data *hdr);
 408extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 409                                char *, uint32_t);
 410extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 411                              char *, int);
 412extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 413                                char *, int);
 414extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 415extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 416extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 417extern void iscsi_requeue_task(struct iscsi_task *task);
 418extern void iscsi_put_task(struct iscsi_task *task);
 419extern void __iscsi_get_task(struct iscsi_task *task);
 420extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 421                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);
 422
 423/*
 424 * generic helpers
 425 */
 426extern void iscsi_pool_free(struct iscsi_pool *);
 427extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 428
 429/*
 430 * inline functions to deal with padding.
 431 */
 432static inline unsigned int
 433iscsi_padded(unsigned int len)
 434{
 435        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 436}
 437
 438static inline unsigned int
 439iscsi_padding(unsigned int len)
 440{
 441        len &= (ISCSI_PAD_LEN - 1);
 442        if (len)
 443                len = ISCSI_PAD_LEN - len;
 444        return len;
 445}
 446
 447#endif
 448
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