LXR linux/include/scsi/libiscsi.h

   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
  34struct scsi_transport_template;
  35struct scsi_host_template;
  36struct scsi_device;
  37struct Scsi_Host;
  38struct scsi_cmnd;
  39struct socket;
  40struct iscsi_transport;
  41struct iscsi_cls_session;
  42struct iscsi_cls_conn;
  43struct iscsi_session;
  44struct iscsi_nopin;
  45struct device;
  46
  47/* #define DEBUG_SCSI */
  48#ifdef DEBUG_SCSI
  49#define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
  50#else
  51#define debug_scsi(fmt...)
  52#endif
  53
  54#define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  55#define ISCSI_MGMT_CMDS_MAX     15
  56
  57#define ISCSI_DEF_CMD_PER_LUN           32
  58#define ISCSI_MAX_CMD_PER_LUN           128
  59
  60/* Task Mgmt states */
  61enum {
  62        TMF_INITIAL,
  63        TMF_QUEUED,
  64        TMF_SUCCESS,
  65        TMF_FAILED,
  66        TMF_TIMEDOUT,
  67        TMF_NOT_FOUND,
  68};
  69
  70/* Connection suspend "bit" */
  71#define ISCSI_SUSPEND_BIT               1
  72
  73#define ISCSI_ITT_MASK                  (0x1fff)
  74#define ISCSI_TOTAL_CMDS_MAX            4096
  75/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  76#define ISCSI_TOTAL_CMDS_MIN            16
  77#define ISCSI_AGE_SHIFT                 28
  78#define ISCSI_AGE_MASK                  (0xf << ISCSI_AGE_SHIFT)
  79
  80#define ISCSI_ADDRESS_BUF_LEN           64
  81
  82enum {
  83        /* this is the maximum possible storage for AHSs */
  84        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  85                                sizeof(struct iscsi_rlength_ahdr),
  86        ISCSI_DIGEST_SIZE = sizeof(__u32),
  87};
  88
  89
  90enum {
  91        ISCSI_TASK_COMPLETED,
  92        ISCSI_TASK_PENDING,
  93        ISCSI_TASK_RUNNING,
  94};
  95
  96struct iscsi_task {
  97        /*
  98         * Because LLDs allocate their hdr differently, this is a pointer
  99         * and length to that storage. It must be setup at session
 100         * creation time.
 101         */
 102        struct iscsi_cmd        *hdr;
 103        unsigned short          hdr_max;
 104        unsigned short          hdr_len;        /* accumulated size of hdr used */
 105        int                     itt;            /* this ITT */
 106
 107        uint32_t                unsol_datasn;
 108        unsigned                imm_count;      /* imm-data (bytes)   */
 109        unsigned                unsol_count;    /* unsolicited (bytes)*/
 110        /* offset in unsolicited stream (bytes); */
 111        unsigned                unsol_offset;
 112        unsigned                data_count;     /* remaining Data-Out */
 113        char                    *data;          /* mgmt payload */
 114        struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 115        struct iscsi_conn       *conn;          /* used connection    */
 116
 117        /* state set/tested under session->lock */
 118        int                     state;
 119        atomic_t                refcount;
 120        struct list_head        running;        /* running cmd list */
 121        void                    *dd_data;       /* driver/transport data */
 122};
 123
 124static inline void* iscsi_next_hdr(struct iscsi_task *task)
 125{
 126        return (void*)task->hdr + task->hdr_len;
 127}
 128
 129/* Connection's states */
 130enum {
 131        ISCSI_CONN_INITIAL_STAGE,
 132        ISCSI_CONN_STARTED,
 133        ISCSI_CONN_STOPPED,
 134        ISCSI_CONN_CLEANUP_WAIT,
 135};
 136
 137struct iscsi_conn {
 138        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 139        void                    *dd_data;       /* iscsi_transport data */
 140        struct iscsi_session    *session;       /* parent session */
 141        /*
 142         * conn_stop() flag: stop to recover, stop to terminate
 143         */
 144        int                     stop_stage;
 145        struct timer_list       transport_timer;
 146        unsigned long           last_recv;
 147        unsigned long           last_ping;
 148        int                     ping_timeout;
 149        int                     recv_timeout;
 150        struct iscsi_task       *ping_task;
 151
 152        /* iSCSI connection-wide sequencing */
 153        uint32_t                exp_statsn;
 154
 155        /* control data */
 156        int                     id;             /* CID */
 157        int                     c_stage;        /* connection state */
 158        /*
 159         * Preallocated buffer for pdus that have data but do not
 160         * originate from scsi-ml. We never have two pdus using the
 161         * buffer at the same time. It is only allocated to
 162         * the default max recv size because the pdus we support
 163         * should always fit in this buffer
 164         */
 165        char                    *data;
 166        struct iscsi_task       *login_task;    /* mtask used for login/text */
 167        struct iscsi_task       *task;          /* xmit task in progress */
 168
 169        /* xmit */
 170        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 171        struct list_head        mgmt_run_list;  /* list of control tasks */
 172        struct list_head        xmitqueue;      /* data-path cmd queue */
 173        struct list_head        run_list;       /* list of cmds in progress */
 174        struct list_head        requeue;        /* tasks needing another run */
 175        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 176        unsigned long           suspend_tx;     /* suspend Tx */
 177        unsigned long           suspend_rx;     /* suspend Rx */
 178
 179        /* abort */
 180        wait_queue_head_t       ehwait;         /* used in eh_abort() */
 181        struct iscsi_tm         tmhdr;
 182        struct timer_list       tmf_timer;
 183        int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 184
 185        /* negotiated params */
 186        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 187        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 188        int                     hdrdgst_en;
 189        int                     datadgst_en;
 190        int                     ifmarker_en;
 191        int                     ofmarker_en;
 192        /* values userspace uses to id a conn */
 193        int                     persistent_port;
 194        char                    *persistent_address;
 195        /* remote portal currently connected to */
 196        int                     portal_port;
 197        char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 198
 199        /* MIB-statistics */
 200        uint64_t                txdata_octets;
 201        uint64_t                rxdata_octets;
 202        uint32_t                scsicmd_pdus_cnt;
 203        uint32_t                dataout_pdus_cnt;
 204        uint32_t                scsirsp_pdus_cnt;
 205        uint32_t                datain_pdus_cnt;
 206        uint32_t                r2t_pdus_cnt;
 207        uint32_t                tmfcmd_pdus_cnt;
 208        int32_t                 tmfrsp_pdus_cnt;
 209
 210        /* custom statistics */
 211        uint32_t                eh_abort_cnt;
 212        uint32_t                fmr_unalign_cnt;
 213};
 214
 215struct iscsi_pool {
 216        struct kfifo            *queue;         /* FIFO Queue */
 217        void                    **pool;         /* Pool of elements */
 218        int                     max;            /* Max number of elements */
 219};
 220
 221/* Session's states */
 222enum {
 223        ISCSI_STATE_FREE = 1,
 224        ISCSI_STATE_LOGGED_IN,
 225        ISCSI_STATE_FAILED,
 226        ISCSI_STATE_TERMINATE,
 227        ISCSI_STATE_IN_RECOVERY,
 228        ISCSI_STATE_RECOVERY_FAILED,
 229        ISCSI_STATE_LOGGING_OUT,
 230};
 231
 232struct iscsi_session {
 233        struct iscsi_cls_session *cls_session;
 234        /*
 235         * Syncs up the scsi eh thread with the iscsi eh thread when sending
 236         * task management functions. This must be taken before the session
 237         * and recv lock.
 238         */
 239        struct mutex            eh_mutex;
 240
 241        /* iSCSI session-wide sequencing */
 242        uint32_t                cmdsn;
 243        uint32_t                exp_cmdsn;
 244        uint32_t                max_cmdsn;
 245
 246        /* This tracks the reqs queued into the initiator */
 247        uint32_t                queued_cmdsn;
 248
 249        /* configuration */
 250        int                     abort_timeout;
 251        int                     lu_reset_timeout;
 252        int                     initial_r2t_en;
 253        unsigned                max_r2t;
 254        int                     imm_data_en;
 255        unsigned                first_burst;
 256        unsigned                max_burst;
 257        int                     time2wait;
 258        int                     time2retain;
 259        int                     pdu_inorder_en;
 260        int                     dataseq_inorder_en;
 261        int                     erl;
 262        int                     fast_abort;
 263        int                     tpgt;
 264        char                    *username;
 265        char                    *username_in;
 266        char                    *password;
 267        char                    *password_in;
 268        char                    *targetname;
 269        char                    *ifacename;
 270        char                    *initiatorname;
 271        /* control data */
 272        struct iscsi_transport  *tt;
 273        struct Scsi_Host        *host;
 274        struct iscsi_conn       *leadconn;      /* leading connection */
 275        spinlock_t              lock;           /* protects session state, *
 276                                                 * sequence numbers,       *
 277                                                 * session resources:      *
 278                                                 * - cmdpool,              *
 279                                                 * - mgmtpool,             *
 280                                                 * - r2tpool               */
 281        int                     state;          /* session state           */
 282        int                     age;            /* counts session re-opens */
 283
 284        int                     scsi_cmds_max;  /* max scsi commands */
 285        int                     cmds_max;       /* size of cmds array */
 286        struct iscsi_task       **cmds;         /* Original Cmds arr */
 287        struct iscsi_pool       cmdpool;        /* PDU's pool */
 288};
 289
 290enum {
 291        ISCSI_HOST_SETUP,
 292        ISCSI_HOST_REMOVED,
 293};
 294
 295struct iscsi_host {
 296        char                    *initiatorname;
 297        /* hw address or netdev iscsi connection is bound to */
 298        char                    *hwaddress;
 299        char                    *netdev;
 300        /* local address */
 301        int                     local_port;
 302        char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 303
 304        wait_queue_head_t       session_removal_wq;
 305        /* protects sessions and state */
 306        spinlock_t              lock;
 307        int                     num_sessions;
 308        int                     state;
 309};
 310
 311/*
 312 * scsi host template
 313 */
 314extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 315extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 316extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 317extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 318extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 319                              void (*done)(struct scsi_cmnd *));
 320
 321/*
 322 * iSCSI host helpers.
 323 */
 324#define iscsi_host_priv(_shost) \
 325        (shost_priv(_shost) + sizeof(struct iscsi_host))
 326
 327extern int iscsi_host_set_param(struct Scsi_Host *shost,
 328                                enum iscsi_host_param param, char *buf,
 329                                int buflen);
 330extern int iscsi_host_get_param(struct Scsi_Host *shost,
 331                                enum iscsi_host_param param, char *buf);
 332extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 333extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 334                                          int dd_data_size, uint16_t qdepth);
 335extern void iscsi_host_remove(struct Scsi_Host *shost);
 336extern void iscsi_host_free(struct Scsi_Host *shost);
 337
 338/*
 339 * session management
 340 */
 341extern struct iscsi_cls_session *
 342iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 343                    uint16_t, int, uint32_t, unsigned int);
 344extern void iscsi_session_teardown(struct iscsi_cls_session *);
 345extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 346extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 347                           enum iscsi_param param, char *buf, int buflen);
 348extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 349                                   enum iscsi_param param, char *buf);
 350
 351#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 352        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 353
 354/*
 355 * connection management
 356 */
 357extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 358                                               int, uint32_t);
 359extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 360extern int iscsi_conn_start(struct iscsi_cls_conn *);
 361extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 362extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 363                           int);
 364extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 365extern void iscsi_session_failure(struct iscsi_cls_session *cls_session,
 366                                  enum iscsi_err err);
 367extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 368                                enum iscsi_param param, char *buf);
 369extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 370
 371#define iscsi_conn_printk(prefix, _c, fmt, a...) \
 372        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 373                              fmt, ##a)
 374
 375/*
 376 * pdu and task processing
 377 */
 378extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 379extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
 380                                        struct iscsi_data *hdr);
 381extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 382                                char *, uint32_t);
 383extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 384                              char *, int);
 385extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 386                                char *, int);
 387extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 388extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 389extern void iscsi_requeue_task(struct iscsi_task *task);
 390extern void iscsi_put_task(struct iscsi_task *task);
 391extern void __iscsi_get_task(struct iscsi_task *task);
 392
 393/*
 394 * generic helpers
 395 */
 396extern void iscsi_pool_free(struct iscsi_pool *);
 397extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 398
 399/*
 400 * inline functions to deal with padding.
 401 */
 402static inline unsigned int
 403iscsi_padded(unsigned int len)
 404{
 405        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 406}
 407
 408static inline unsigned int
 409iscsi_padding(unsigned int len)
 410{
 411        len &= (ISCSI_PAD_LEN - 1);
 412        if (len)
 413                len = ISCSI_PAD_LEN - len;
 414        return len;
 415}
 416
 417#endif
 418