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 #include <scsi/scsi_transport_iscsi.h>
  34
  35 struct scsi_transport_template;
  36 struct scsi_host_template;
  37 struct scsi_device;
  38 struct Scsi_Host;
  39 struct scsi_target;
  40 struct scsi_cmnd;
  41 struct socket;
  42 struct iscsi_transport;
  43 struct iscsi_cls_session;
  44 struct iscsi_cls_conn;
  45 struct iscsi_session;
  46 struct iscsi_nopin;
  47 struct 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 */
  55 enum {
  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
  76 enum {
  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
  84 enum {
  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
  93 struct 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
 104 struct 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
 139 static 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
 144 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 145 {
 146         return (void*)task->hdr + task->hdr_len;
 147 }
 148
 149 /* Connection's states */
 150 enum {
 151         ISCSI_CONN_INITIAL_STAGE,
 152         ISCSI_CONN_STARTED,
 153         ISCSI_CONN_STOPPED,
 154         ISCSI_CONN_CLEANUP_WAIT,
 155 };
 156
 157 struct 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
 233 struct 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 */
 240 enum {
 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
 250 struct 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 };
 307
 308 enum {
 309         ISCSI_HOST_SETUP,
 310         ISCSI_HOST_REMOVED,
 311 };
 312
 313 struct iscsi_host {
 314         char                    *initiatorname;
 315         /* hw address or netdev iscsi connection is bound to */
 316         char                    *hwaddress;
 317         char                    *netdev;
 318         /* local address */
 319         int                     local_port;
 320         char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 321
 322         wait_queue_head_t       session_removal_wq;
 323         /* protects sessions and state */
 324         spinlock_t              lock;
 325         int                     num_sessions;
 326         int                     state;
 327
 328         struct workqueue_struct *workq;
 329         char                    workq_name[20];
 330 };
 331
 332 /*
 333  * scsi host template
 334  */
 335 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 336 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 337 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 338 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 339 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 340                               void (*done)(struct scsi_cmnd *));
 341
 342 /*
 343  * iSCSI host helpers.
 344  */
 345 #define iscsi_host_priv(_shost) \
 346         (shost_priv(_shost) + sizeof(struct iscsi_host))
 347
 348 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 349                                 enum iscsi_host_param param, char *buf,
 350                                 int buflen);
 351 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 352                                 enum iscsi_host_param param, char *buf);
 353 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 354 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 355                                           int dd_data_size,
 356                                           bool xmit_can_sleep);
 357 extern void iscsi_host_remove(struct Scsi_Host *shost);
 358 extern void iscsi_host_free(struct Scsi_Host *shost);
 359 extern int iscsi_target_alloc(struct scsi_target *starget);
 360
 361 /*
 362  * session management
 363  */
 364 extern struct iscsi_cls_session *
 365 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 366                     uint16_t, int, uint32_t, unsigned int);
 367 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 368 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 369 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 370                            enum iscsi_param param, char *buf, int buflen);
 371 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 372                                    enum iscsi_param param, char *buf);
 373
 374 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 375         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 376
 377 /*
 378  * connection management
 379  */
 380 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 381                                                int, uint32_t);
 382 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 383 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 384 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 385 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 386                            int);
 387 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 388 extern void iscsi_session_failure(struct iscsi_session *session,
 389                                   enum iscsi_err err);
 390 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 391                                 enum iscsi_param param, char *buf);
 392 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 393 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 394
 395 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 396         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 397                               fmt, ##a)
 398
 399 /*
 400  * pdu and task processing
 401  */
 402 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 403 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 404                                     struct iscsi_r2t_info *r2t,
 405                                     struct iscsi_data *hdr);
 406 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 407                                 char *, uint32_t);
 408 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 409                               char *, int);
 410 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 411                                 char *, int);
 412 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 413 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 414 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 415 extern void iscsi_requeue_task(struct iscsi_task *task);
 416 extern void iscsi_put_task(struct iscsi_task *task);
 417 extern void __iscsi_get_task(struct iscsi_task *task);
 418
 419 /*
 420  * generic helpers
 421  */
 422 extern void iscsi_pool_free(struct iscsi_pool *);
 423 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 424
 425 /*
 426  * inline functions to deal with padding.
 427  */
 428 static inline unsigned int
 429 iscsi_padded(unsigned int len)
 430 {
 431         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 432 }
 433
 434 static inline unsigned int
 435 iscsi_padding(unsigned int len)
 436 {
 437         len &= (ISCSI_PAD_LEN - 1);
 438         if (len)
 439                 len = ISCSI_PAD_LEN - len;
 440         return len;
 441 }
 442
 443 #endif