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     15
  56
  57 #define ISCSI_DEF_CMD_PER_LUN           32
  58 #define ISCSI_MAX_CMD_PER_LUN           128
  59
  60 /* Task Mgmt states */
  61 enum {
  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
  82 enum {
  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
  90 enum {
  91         ISCSI_TASK_COMPLETED,
  92         ISCSI_TASK_PENDING,
  93         ISCSI_TASK_RUNNING,
  94 };
  95
  96 struct 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
 124 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 125 {
 126         return (void*)task->hdr + task->hdr_len;
 127 }
 128
 129 /* Connection's states */
 130 enum {
 131         ISCSI_CONN_INITIAL_STAGE,
 132         ISCSI_CONN_STARTED,
 133         ISCSI_CONN_STOPPED,
 134         ISCSI_CONN_CLEANUP_WAIT,
 135 };
 136
 137 struct 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
 215 struct 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 */
 222 enum {
 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
 232 struct 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
 290 enum {
 291         ISCSI_HOST_SETUP,
 292         ISCSI_HOST_REMOVED,
 293 };
 294
 295 struct 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  */
 314 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 315 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 316 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 317 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 318 extern 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
 327 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 328                                 enum iscsi_host_param param, char *buf,
 329                                 int buflen);
 330 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 331                                 enum iscsi_host_param param, char *buf);
 332 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 333 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 334                                           int dd_data_size, uint16_t qdepth);
 335 extern void iscsi_host_remove(struct Scsi_Host *shost);
 336 extern void iscsi_host_free(struct Scsi_Host *shost);
 337
 338 /*
 339  * session management
 340  */
 341 extern struct iscsi_cls_session *
 342 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 343                     uint16_t, int, uint32_t, unsigned int);
 344 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 345 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 346 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 347                            enum iscsi_param param, char *buf, int buflen);
 348 extern 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  */
 357 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 358                                                int, uint32_t);
 359 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 360 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 361 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 362 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 363                            int);
 364 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 365 extern void iscsi_session_failure(struct iscsi_cls_session *cls_session,
 366                                   enum iscsi_err err);
 367 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 368                                 enum iscsi_param param, char *buf);
 369 extern 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  */
 378 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 379 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_task *,
 380                                         struct iscsi_data *hdr);
 381 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 382                                 char *, uint32_t);
 383 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 384                               char *, int);
 385 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 386                                 char *, int);
 387 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 388 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 389 extern void iscsi_requeue_task(struct iscsi_task *task);
 390 extern void iscsi_put_task(struct iscsi_task *task);
 391 extern void __iscsi_get_task(struct iscsi_task *task);
 392
 393 /*
 394  * generic helpers
 395  */
 396 extern void iscsi_pool_free(struct iscsi_pool *);
 397 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 398
 399 /*
 400  * inline functions to deal with padding.
 401  */
 402 static inline unsigned int
 403 iscsi_padded(unsigned int len)
 404 {
 405         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 406 }
 407
 408 static inline unsigned int
 409 iscsi_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