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_cmnd;
  40 struct socket;
  41 struct iscsi_transport;
  42 struct iscsi_cls_session;
  43 struct iscsi_cls_conn;
  44 struct iscsi_session;
  45 struct iscsi_nopin;
  46 struct device;
  47
  48 #define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  49 #define ISCSI_MGMT_CMDS_MAX     15
  50
  51 #define ISCSI_DEF_CMD_PER_LUN   32
  52
  53 /* Task Mgmt states */
  54 enum {
  55         TMF_INITIAL,
  56         TMF_QUEUED,
  57         TMF_SUCCESS,
  58         TMF_FAILED,
  59         TMF_TIMEDOUT,
  60         TMF_NOT_FOUND,
  61 };
  62
  63 /* Connection suspend "bit" */
  64 #define ISCSI_SUSPEND_BIT               1
  65
  66 #define ISCSI_ITT_MASK                  0x1fff
  67 #define ISCSI_TOTAL_CMDS_MAX            4096
  68 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  69 #define ISCSI_TOTAL_CMDS_MIN            16
  70 #define ISCSI_AGE_SHIFT                 28
  71 #define ISCSI_AGE_MASK                  0xf
  72
  73 #define ISCSI_ADDRESS_BUF_LEN           64
  74
  75 enum {
  76         /* this is the maximum possible storage for AHSs */
  77         ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  78                                 sizeof(struct iscsi_rlength_ahdr),
  79         ISCSI_DIGEST_SIZE = sizeof(__u32),
  80 };
  81
  82
  83 enum {
  84         ISCSI_TASK_COMPLETED,
  85         ISCSI_TASK_PENDING,
  86         ISCSI_TASK_RUNNING,
  87 };
  88
  89 struct iscsi_r2t_info {
  90         __be32                  ttt;            /* copied from R2T */
  91         __be32                  exp_statsn;     /* copied from R2T */
  92         uint32_t                data_length;    /* copied from R2T */
  93         uint32_t                data_offset;    /* copied from R2T */
  94         int                     data_count;     /* DATA-Out payload progress */
  95         int                     datasn;
  96         /* LLDs should set/update these values */
  97         int                     sent;           /* R2T sequence progress */
  98 };
  99
 100 struct iscsi_task {
 101         /*
 102          * Because LLDs allocate their hdr differently, this is a pointer
 103          * and length to that storage. It must be setup at session
 104          * creation time.
 105          */
 106         struct iscsi_hdr        *hdr;
 107         unsigned short          hdr_max;
 108         unsigned short          hdr_len;        /* accumulated size of hdr used */
 109         /* copied values in case we need to send tmfs */
 110         itt_t                   hdr_itt;
 111         __be32                  cmdsn;
 112         uint8_t                 lun[8];
 113
 114         int                     itt;            /* this ITT */
 115
 116         unsigned                imm_count;      /* imm-data (bytes)   */
 117         /* offset in unsolicited stream (bytes); */
 118         struct iscsi_r2t_info   unsol_r2t;
 119         char                    *data;          /* mgmt payload */
 120         unsigned                data_count;
 121         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 122         struct iscsi_conn       *conn;          /* used connection    */
 123
 124         /* state set/tested under session->lock */
 125         int                     state;
 126         atomic_t                refcount;
 127         struct list_head        running;        /* running cmd list */
 128         void                    *dd_data;       /* driver/transport data */
 129 };
 130
 131 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 132 {
 133         return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 134 }
 135
 136 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 137 {
 138         return (void*)task->hdr + task->hdr_len;
 139 }
 140
 141 /* Connection's states */
 142 enum {
 143         ISCSI_CONN_INITIAL_STAGE,
 144         ISCSI_CONN_STARTED,
 145         ISCSI_CONN_STOPPED,
 146         ISCSI_CONN_CLEANUP_WAIT,
 147 };
 148
 149 struct iscsi_conn {
 150         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 151         void                    *dd_data;       /* iscsi_transport data */
 152         struct iscsi_session    *session;       /* parent session */
 153         /*
 154          * conn_stop() flag: stop to recover, stop to terminate
 155          */
 156         int                     stop_stage;
 157         struct timer_list       transport_timer;
 158         unsigned long           last_recv;
 159         unsigned long           last_ping;
 160         int                     ping_timeout;
 161         int                     recv_timeout;
 162         struct iscsi_task       *ping_task;
 163
 164         /* iSCSI connection-wide sequencing */
 165         uint32_t                exp_statsn;
 166
 167         /* control data */
 168         int                     id;             /* CID */
 169         int                     c_stage;        /* connection state */
 170         /*
 171          * Preallocated buffer for pdus that have data but do not
 172          * originate from scsi-ml. We never have two pdus using the
 173          * buffer at the same time. It is only allocated to
 174          * the default max recv size because the pdus we support
 175          * should always fit in this buffer
 176          */
 177         char                    *data;
 178         struct iscsi_task       *login_task;    /* mtask used for login/text */
 179         struct iscsi_task       *task;          /* xmit task in progress */
 180
 181         /* xmit */
 182         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 183         struct list_head        mgmt_run_list;  /* list of control tasks */
 184         struct list_head        xmitqueue;      /* data-path cmd queue */
 185         struct list_head        run_list;       /* list of cmds in progress */
 186         struct list_head        requeue;        /* tasks needing another run */
 187         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 188         unsigned long           suspend_tx;     /* suspend Tx */
 189         unsigned long           suspend_rx;     /* suspend Rx */
 190
 191         /* abort */
 192         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 193         struct iscsi_tm         tmhdr;
 194         struct timer_list       tmf_timer;
 195         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 196
 197         /* negotiated params */
 198         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 199         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 200         int                     hdrdgst_en;
 201         int                     datadgst_en;
 202         int                     ifmarker_en;
 203         int                     ofmarker_en;
 204         /* values userspace uses to id a conn */
 205         int                     persistent_port;
 206         char                    *persistent_address;
 207         /* remote portal currently connected to */
 208         int                     portal_port;
 209         char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 210
 211         /* MIB-statistics */
 212         uint64_t                txdata_octets;
 213         uint64_t                rxdata_octets;
 214         uint32_t                scsicmd_pdus_cnt;
 215         uint32_t                dataout_pdus_cnt;
 216         uint32_t                scsirsp_pdus_cnt;
 217         uint32_t                datain_pdus_cnt;
 218         uint32_t                r2t_pdus_cnt;
 219         uint32_t                tmfcmd_pdus_cnt;
 220         int32_t                 tmfrsp_pdus_cnt;
 221
 222         /* custom statistics */
 223         uint32_t                eh_abort_cnt;
 224         uint32_t                fmr_unalign_cnt;
 225 };
 226
 227 struct iscsi_pool {
 228         struct kfifo            *queue;         /* FIFO Queue */
 229         void                    **pool;         /* Pool of elements */
 230         int                     max;            /* Max number of elements */
 231 };
 232
 233 /* Session's states */
 234 enum {
 235         ISCSI_STATE_FREE = 1,
 236         ISCSI_STATE_LOGGED_IN,
 237         ISCSI_STATE_FAILED,
 238         ISCSI_STATE_TERMINATE,
 239         ISCSI_STATE_IN_RECOVERY,
 240         ISCSI_STATE_RECOVERY_FAILED,
 241         ISCSI_STATE_LOGGING_OUT,
 242 };
 243
 244 struct iscsi_session {
 245         struct iscsi_cls_session *cls_session;
 246         /*
 247          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 248          * task management functions. This must be taken before the session
 249          * and recv lock.
 250          */
 251         struct mutex            eh_mutex;
 252
 253         /* iSCSI session-wide sequencing */
 254         uint32_t                cmdsn;
 255         uint32_t                exp_cmdsn;
 256         uint32_t                max_cmdsn;
 257
 258         /* This tracks the reqs queued into the initiator */
 259         uint32_t                queued_cmdsn;
 260
 261         /* configuration */
 262         int                     abort_timeout;
 263         int                     lu_reset_timeout;
 264         int                     initial_r2t_en;
 265         unsigned                max_r2t;
 266         int                     imm_data_en;
 267         unsigned                first_burst;
 268         unsigned                max_burst;
 269         int                     time2wait;
 270         int                     time2retain;
 271         int                     pdu_inorder_en;
 272         int                     dataseq_inorder_en;
 273         int                     erl;
 274         int                     fast_abort;
 275         int                     tpgt;
 276         char                    *username;
 277         char                    *username_in;
 278         char                    *password;
 279         char                    *password_in;
 280         char                    *targetname;
 281         char                    *ifacename;
 282         char                    *initiatorname;
 283         /* control data */
 284         struct iscsi_transport  *tt;
 285         struct Scsi_Host        *host;
 286         struct iscsi_conn       *leadconn;      /* leading connection */
 287         spinlock_t              lock;           /* protects session state, *
 288                                                  * sequence numbers,       *
 289                                                  * session resources:      *
 290                                                  * - cmdpool,              *
 291                                                  * - mgmtpool,             *
 292                                                  * - r2tpool               */
 293         int                     state;          /* session state           */
 294         int                     age;            /* counts session re-opens */
 295
 296         int                     scsi_cmds_max;  /* max scsi commands */
 297         int                     cmds_max;       /* size of cmds array */
 298         struct iscsi_task       **cmds;         /* Original Cmds arr */
 299         struct iscsi_pool       cmdpool;        /* PDU's pool */
 300 };
 301
 302 enum {
 303         ISCSI_HOST_SETUP,
 304         ISCSI_HOST_REMOVED,
 305 };
 306
 307 struct iscsi_host {
 308         char                    *initiatorname;
 309         /* hw address or netdev iscsi connection is bound to */
 310         char                    *hwaddress;
 311         char                    *netdev;
 312         /* local address */
 313         int                     local_port;
 314         char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 315
 316         wait_queue_head_t       session_removal_wq;
 317         /* protects sessions and state */
 318         spinlock_t              lock;
 319         int                     num_sessions;
 320         int                     state;
 321
 322         struct workqueue_struct *workq;
 323         char                    workq_name[20];
 324 };
 325
 326 /*
 327  * scsi host template
 328  */
 329 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 330 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 331 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 332 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 333 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 334                               void (*done)(struct scsi_cmnd *));
 335
 336 /*
 337  * iSCSI host helpers.
 338  */
 339 #define iscsi_host_priv(_shost) \
 340         (shost_priv(_shost) + sizeof(struct iscsi_host))
 341
 342 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 343                                 enum iscsi_host_param param, char *buf,
 344                                 int buflen);
 345 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 346                                 enum iscsi_host_param param, char *buf);
 347 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 348 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 349                                           int dd_data_size,
 350                                           bool xmit_can_sleep);
 351 extern void iscsi_host_remove(struct Scsi_Host *shost);
 352 extern void iscsi_host_free(struct Scsi_Host *shost);
 353
 354 /*
 355  * session management
 356  */
 357 extern struct iscsi_cls_session *
 358 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 359                     uint16_t, int, uint32_t, unsigned int);
 360 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 361 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 362 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 363                            enum iscsi_param param, char *buf, int buflen);
 364 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 365                                    enum iscsi_param param, char *buf);
 366
 367 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 368         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 369
 370 /*
 371  * connection management
 372  */
 373 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 374                                                int, uint32_t);
 375 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 376 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 377 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 378 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 379                            int);
 380 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 381 extern void iscsi_session_failure(struct iscsi_session *session,
 382                                   enum iscsi_err err);
 383 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 384                                 enum iscsi_param param, char *buf);
 385 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 386 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 387
 388 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 389         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 390                               fmt, ##a)
 391
 392 /*
 393  * pdu and task processing
 394  */
 395 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 396 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 397                                     struct iscsi_r2t_info *r2t,
 398                                     struct iscsi_data *hdr);
 399 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 400                                 char *, uint32_t);
 401 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 402                               char *, int);
 403 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 404                                 char *, int);
 405 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 406 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 407 extern void iscsi_requeue_task(struct iscsi_task *task);
 408 extern void iscsi_put_task(struct iscsi_task *task);
 409 extern void __iscsi_get_task(struct iscsi_task *task);
 410
 411 /*
 412  * generic helpers
 413  */
 414 extern void iscsi_pool_free(struct iscsi_pool *);
 415 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 416
 417 /*
 418  * inline functions to deal with padding.
 419  */
 420 static inline unsigned int
 421 iscsi_padded(unsigned int len)
 422 {
 423         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 424 }
 425
 426 static inline unsigned int
 427 iscsi_padding(unsigned int len)
 428 {
 429         len &= (ISCSI_PAD_LEN - 1);
 430         if (len)
 431                 len = ISCSI_PAD_LEN - len;
 432         return len;
 433 }
 434
 435 #endif