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
  34 struct scsi_transport_template;
  35 struct scsi_host_template;
  36 struct scsi_device;
  37 struct Scsi_Host;
  38 struct scsi_cmnd;
  39 struct socket;
  40 struct iscsi_transport;
  41 struct iscsi_cls_session;
  42 struct iscsi_cls_conn;
  43 struct iscsi_session;
  44 struct iscsi_nopin;
  45 struct 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     16      /* must be power of 2 */
  56
  57 #define ISCSI_MGMT_ITT_OFFSET   0xa00
  58
  59 #define ISCSI_DEF_CMD_PER_LUN           32
  60 #define ISCSI_MAX_CMD_PER_LUN           128
  61
  62 /* Task Mgmt states */
  63 enum {
  64         TMF_INITIAL,
  65         TMF_QUEUED,
  66         TMF_SUCCESS,
  67         TMF_FAILED,
  68         TMF_TIMEDOUT,
  69         TMF_NOT_FOUND,
  70 };
  71
  72 /* Connection suspend "bit" */
  73 #define ISCSI_SUSPEND_BIT               1
  74
  75 #define ISCSI_ITT_MASK                  (0xfff)
  76 #define ISCSI_AGE_SHIFT                 28
  77 #define ISCSI_AGE_MASK                  (0xf << ISCSI_AGE_SHIFT)
  78
  79 #define ISCSI_ADDRESS_BUF_LEN           64
  80
  81 enum {
  82         /* this is the maximum possible storage for AHSs */
  83         ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  84                                 sizeof(struct iscsi_rlength_ahdr),
  85         ISCSI_DIGEST_SIZE = sizeof(__u32),
  86 };
  87
  88
  89 enum {
  90         ISCSI_TASK_COMPLETED,
  91         ISCSI_TASK_PENDING,
  92         ISCSI_TASK_RUNNING,
  93 };
  94
  95 struct iscsi_task {
  96         /*
  97          * Because LLDs allocate their hdr differently, this is a pointer
  98          * and length to that storage. It must be setup at session
  99          * creation time.
 100          */
 101         struct iscsi_cmd        *hdr;
 102         unsigned short          hdr_max;
 103         unsigned short          hdr_len;        /* accumulated size of hdr used */
 104         int                     itt;            /* this ITT */
 105
 106         uint32_t                unsol_datasn;
 107         unsigned                imm_count;      /* imm-data (bytes)   */
 108         unsigned                unsol_count;    /* unsolicited (bytes)*/
 109         /* offset in unsolicited stream (bytes); */
 110         unsigned                unsol_offset;
 111         unsigned                data_count;     /* remaining Data-Out */
 112         char                    *data;          /* mgmt payload */
 113         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 114         struct iscsi_conn       *conn;          /* used connection    */
 115
 116         /* state set/tested under session->lock */
 117         int                     state;
 118         atomic_t                refcount;
 119         struct list_head        running;        /* running cmd list */
 120         void                    *dd_data;       /* driver/transport data */
 121 };
 122
 123 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 124 {
 125         return (void*)task->hdr + task->hdr_len;
 126 }
 127
 128 /* Connection's states */
 129 enum {
 130         ISCSI_CONN_INITIAL_STAGE,
 131         ISCSI_CONN_STARTED,
 132         ISCSI_CONN_STOPPED,
 133         ISCSI_CONN_CLEANUP_WAIT,
 134 };
 135
 136 struct iscsi_conn {
 137         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 138         void                    *dd_data;       /* iscsi_transport data */
 139         struct iscsi_session    *session;       /* parent session */
 140         /*
 141          * LLDs should set this lock. It protects the transport recv
 142          * code
 143          */
 144         rwlock_t                *recv_lock;
 145         /*
 146          * conn_stop() flag: stop to recover, stop to terminate
 147          */
 148         int                     stop_stage;
 149         struct timer_list       transport_timer;
 150         unsigned long           last_recv;
 151         unsigned long           last_ping;
 152         int                     ping_timeout;
 153         int                     recv_timeout;
 154         struct iscsi_task       *ping_task;
 155
 156         /* iSCSI connection-wide sequencing */
 157         uint32_t                exp_statsn;
 158
 159         /* control data */
 160         int                     id;             /* CID */
 161         int                     c_stage;        /* connection state */
 162         /*
 163          * Preallocated buffer for pdus that have data but do not
 164          * originate from scsi-ml. We never have two pdus using the
 165          * buffer at the same time. It is only allocated to
 166          * the default max recv size because the pdus we support
 167          * should always fit in this buffer
 168          */
 169         char                    *data;
 170         struct iscsi_task       *login_task;    /* mtask used for login/text */
 171         struct iscsi_task       *task;          /* xmit task in progress */
 172
 173         /* xmit */
 174         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 175         struct list_head        mgmt_run_list;  /* list of control tasks */
 176         struct list_head        xmitqueue;      /* data-path cmd queue */
 177         struct list_head        run_list;       /* list of cmds in progress */
 178         struct list_head        requeue;        /* tasks needing another run */
 179         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 180         unsigned long           suspend_tx;     /* suspend Tx */
 181         unsigned long           suspend_rx;     /* suspend Rx */
 182
 183         /* abort */
 184         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 185         struct iscsi_tm         tmhdr;
 186         struct timer_list       tmf_timer;
 187         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 188
 189         /* negotiated params */
 190         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 191         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 192         int                     hdrdgst_en;
 193         int                     datadgst_en;
 194         int                     ifmarker_en;
 195         int                     ofmarker_en;
 196         /* values userspace uses to id a conn */
 197         int                     persistent_port;
 198         char                    *persistent_address;
 199         /* remote portal currently connected to */
 200         int                     portal_port;
 201         char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 202
 203         /* MIB-statistics */
 204         uint64_t                txdata_octets;
 205         uint64_t                rxdata_octets;
 206         uint32_t                scsicmd_pdus_cnt;
 207         uint32_t                dataout_pdus_cnt;
 208         uint32_t                scsirsp_pdus_cnt;
 209         uint32_t                datain_pdus_cnt;
 210         uint32_t                r2t_pdus_cnt;
 211         uint32_t                tmfcmd_pdus_cnt;
 212         int32_t                 tmfrsp_pdus_cnt;
 213
 214         /* custom statistics */
 215         uint32_t                eh_abort_cnt;
 216         uint32_t                fmr_unalign_cnt;
 217 };
 218
 219 struct iscsi_pool {
 220         struct kfifo            *queue;         /* FIFO Queue */
 221         void                    **pool;         /* Pool of elements */
 222         int                     max;            /* Max number of elements */
 223 };
 224
 225 /* Session's states */
 226 enum {
 227         ISCSI_STATE_FREE = 1,
 228         ISCSI_STATE_LOGGED_IN,
 229         ISCSI_STATE_FAILED,
 230         ISCSI_STATE_TERMINATE,
 231         ISCSI_STATE_IN_RECOVERY,
 232         ISCSI_STATE_RECOVERY_FAILED,
 233         ISCSI_STATE_LOGGING_OUT,
 234 };
 235
 236 struct iscsi_session {
 237         struct iscsi_cls_session *cls_session;
 238         /*
 239          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 240          * task management functions. This must be taken before the session
 241          * and recv lock.
 242          */
 243         struct mutex            eh_mutex;
 244
 245         /* iSCSI session-wide sequencing */
 246         uint32_t                cmdsn;
 247         uint32_t                exp_cmdsn;
 248         uint32_t                max_cmdsn;
 249
 250         /* This tracks the reqs queued into the initiator */
 251         uint32_t                queued_cmdsn;
 252
 253         /* configuration */
 254         int                     abort_timeout;
 255         int                     lu_reset_timeout;
 256         int                     initial_r2t_en;
 257         unsigned                max_r2t;
 258         int                     imm_data_en;
 259         unsigned                first_burst;
 260         unsigned                max_burst;
 261         int                     time2wait;
 262         int                     time2retain;
 263         int                     pdu_inorder_en;
 264         int                     dataseq_inorder_en;
 265         int                     erl;
 266         int                     fast_abort;
 267         int                     tpgt;
 268         char                    *username;
 269         char                    *username_in;
 270         char                    *password;
 271         char                    *password_in;
 272         char                    *targetname;
 273         /* control data */
 274         struct iscsi_transport  *tt;
 275         struct Scsi_Host        *host;
 276         struct iscsi_conn       *leadconn;      /* leading connection */
 277         spinlock_t              lock;           /* protects session state, *
 278                                                  * sequence numbers,       *
 279                                                  * session resources:      *
 280                                                  * - cmdpool,              *
 281                                                  * - mgmtpool,             *
 282                                                  * - r2tpool               */
 283         int                     state;          /* session state           */
 284         int                     age;            /* counts session re-opens */
 285
 286         int                     scsi_cmds_max;  /* max scsi commands */
 287         int                     cmds_max;       /* size of cmds array */
 288         struct iscsi_task       **cmds;         /* Original Cmds arr */
 289         struct iscsi_pool       cmdpool;        /* PDU's pool */
 290 };
 291
 292 struct iscsi_host {
 293         char                    *initiatorname;
 294         /* hw address or netdev iscsi connection is bound to */
 295         char                    *hwaddress;
 296         char                    *netdev;
 297         /* local address */
 298         int                     local_port;
 299         char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 300 };
 301
 302 /*
 303  * scsi host template
 304  */
 305 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 306 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 307 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
 308 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 309 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 310                               void (*done)(struct scsi_cmnd *));
 311
 312 /*
 313  * iSCSI host helpers.
 314  */
 315 #define iscsi_host_priv(_shost) \
 316         (shost_priv(_shost) + sizeof(struct iscsi_host))
 317
 318 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 319                                 enum iscsi_host_param param, char *buf,
 320                                 int buflen);
 321 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 322                                 enum iscsi_host_param param, char *buf);
 323 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 324 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 325                                           int dd_data_size, uint16_t qdepth);
 326 extern void iscsi_host_remove(struct Scsi_Host *shost);
 327 extern void iscsi_host_free(struct Scsi_Host *shost);
 328
 329 /*
 330  * session management
 331  */
 332 extern struct iscsi_cls_session *
 333 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 334                     uint16_t, int, uint32_t, unsigned int);
 335 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 336 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 337 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 338                            enum iscsi_param param, char *buf, int buflen);
 339 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 340                                    enum iscsi_param param, char *buf);
 341
 342 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 343         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 344
 345 /*
 346  * connection management
 347  */
 348 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 349                                                int, uint32_t);
 350 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 351 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 352 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 353 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 354                            int);
 355 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 356 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 357                                 enum iscsi_param param, char *buf);
 358 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 359
 360 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 361         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 362                               fmt, ##a)
 363
 364 /*
 365  * pdu and task processing
 366  */
 367 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 368 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
 369                                         struct iscsi_data *hdr);
 370 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 371                                 char *, uint32_t);
 372 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 373                               char *, int);
 374 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 375 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 376 extern void iscsi_requeue_task(struct iscsi_task *task);
 377 extern void iscsi_put_task(struct iscsi_task *task);
 378
 379 /*
 380  * generic helpers
 381  */
 382 extern void iscsi_pool_free(struct iscsi_pool *);
 383 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 384
 385 /*
 386  * inline functions to deal with padding.
 387  */
 388 static inline unsigned int
 389 iscsi_padded(unsigned int len)
 390 {
 391         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 392 }
 393
 394 static inline unsigned int
 395 iscsi_padding(unsigned int len)
 396 {
 397         len &= (ISCSI_PAD_LEN - 1);
 398         if (len)
 399                 len = ISCSI_PAD_LEN - len;
 400         return len;
 401 }
 402
 403 #endif