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_COMPLETED,
  86         ISCSI_TASK_PENDING,
  87         ISCSI_TASK_RUNNING,
  88 };
  89
  90 struct iscsi_r2t_info {
  91         __be32                  ttt;            /* copied from R2T */
  92         __be32                  exp_statsn;     /* copied from R2T */
  93         uint32_t                data_length;    /* copied from R2T */
  94         uint32_t                data_offset;    /* copied from R2T */
  95         int                     data_count;     /* DATA-Out payload progress */
  96         int                     datasn;
  97         /* LLDs should set/update these values */
  98         int                     sent;           /* R2T sequence progress */
  99 };
 100
 101 struct iscsi_task {
 102         /*
 103          * Because LLDs allocate their hdr differently, this is a pointer
 104          * and length to that storage. It must be setup at session
 105          * creation time.
 106          */
 107         struct iscsi_hdr        *hdr;
 108         unsigned short          hdr_max;
 109         unsigned short          hdr_len;        /* accumulated size of hdr used */
 110         /* copied values in case we need to send tmfs */
 111         itt_t                   hdr_itt;
 112         __be32                  cmdsn;
 113         uint8_t                 lun[8];
 114
 115         int                     itt;            /* this ITT */
 116
 117         unsigned                imm_count;      /* imm-data (bytes)   */
 118         /* offset in unsolicited stream (bytes); */
 119         struct iscsi_r2t_info   unsol_r2t;
 120         char                    *data;          /* mgmt payload */
 121         unsigned                data_count;
 122         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 123         struct iscsi_conn       *conn;          /* used connection    */
 124
 125         /* state set/tested under session->lock */
 126         int                     state;
 127         atomic_t                refcount;
 128         struct list_head        running;        /* running cmd list */
 129         void                    *dd_data;       /* driver/transport data */
 130 };
 131
 132 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 133 {
 134         return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 135 }
 136
 137 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 138 {
 139         return (void*)task->hdr + task->hdr_len;
 140 }
 141
 142 /* Connection's states */
 143 enum {
 144         ISCSI_CONN_INITIAL_STAGE,
 145         ISCSI_CONN_STARTED,
 146         ISCSI_CONN_STOPPED,
 147         ISCSI_CONN_CLEANUP_WAIT,
 148 };
 149
 150 struct iscsi_conn {
 151         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 152         void                    *dd_data;       /* iscsi_transport data */
 153         struct iscsi_session    *session;       /* parent session */
 154         /*
 155          * conn_stop() flag: stop to recover, stop to terminate
 156          */
 157         int                     stop_stage;
 158         struct timer_list       transport_timer;
 159         unsigned long           last_recv;
 160         unsigned long           last_ping;
 161         int                     ping_timeout;
 162         int                     recv_timeout;
 163         struct iscsi_task       *ping_task;
 164
 165         /* iSCSI connection-wide sequencing */
 166         uint32_t                exp_statsn;
 167
 168         /* control data */
 169         int                     id;             /* CID */
 170         int                     c_stage;        /* connection state */
 171         /*
 172          * Preallocated buffer for pdus that have data but do not
 173          * originate from scsi-ml. We never have two pdus using the
 174          * buffer at the same time. It is only allocated to
 175          * the default max recv size because the pdus we support
 176          * should always fit in this buffer
 177          */
 178         char                    *data;
 179         struct iscsi_task       *login_task;    /* mtask used for login/text */
 180         struct iscsi_task       *task;          /* xmit task in progress */
 181
 182         /* xmit */
 183         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 184         struct list_head        mgmt_run_list;  /* list of control tasks */
 185         struct list_head        xmitqueue;      /* data-path cmd queue */
 186         struct list_head        run_list;       /* list of cmds in progress */
 187         struct list_head        requeue;        /* tasks needing another run */
 188         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 189         unsigned long           suspend_tx;     /* suspend Tx */
 190         unsigned long           suspend_rx;     /* suspend Rx */
 191
 192         /* abort */
 193         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 194         struct iscsi_tm         tmhdr;
 195         struct timer_list       tmf_timer;
 196         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 197
 198         /* negotiated params */
 199         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 200         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 201         int                     hdrdgst_en;
 202         int                     datadgst_en;
 203         int                     ifmarker_en;
 204         int                     ofmarker_en;
 205         /* values userspace uses to id a conn */
 206         int                     persistent_port;
 207         char                    *persistent_address;
 208         /* remote portal currently connected to */
 209         int                     portal_port;
 210         char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 211
 212         /* MIB-statistics */
 213         uint64_t                txdata_octets;
 214         uint64_t                rxdata_octets;
 215         uint32_t                scsicmd_pdus_cnt;
 216         uint32_t                dataout_pdus_cnt;
 217         uint32_t                scsirsp_pdus_cnt;
 218         uint32_t                datain_pdus_cnt;
 219         uint32_t                r2t_pdus_cnt;
 220         uint32_t                tmfcmd_pdus_cnt;
 221         int32_t                 tmfrsp_pdus_cnt;
 222
 223         /* custom statistics */
 224         uint32_t                eh_abort_cnt;
 225         uint32_t                fmr_unalign_cnt;
 226 };
 227
 228 struct iscsi_pool {
 229         struct kfifo            *queue;         /* FIFO Queue */
 230         void                    **pool;         /* Pool of elements */
 231         int                     max;            /* Max number of elements */
 232 };
 233
 234 /* Session's states */
 235 enum {
 236         ISCSI_STATE_FREE = 1,
 237         ISCSI_STATE_LOGGED_IN,
 238         ISCSI_STATE_FAILED,
 239         ISCSI_STATE_TERMINATE,
 240         ISCSI_STATE_IN_RECOVERY,
 241         ISCSI_STATE_RECOVERY_FAILED,
 242         ISCSI_STATE_LOGGING_OUT,
 243 };
 244
 245 struct iscsi_session {
 246         struct iscsi_cls_session *cls_session;
 247         /*
 248          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 249          * task management functions. This must be taken before the session
 250          * and recv lock.
 251          */
 252         struct mutex            eh_mutex;
 253
 254         /* iSCSI session-wide sequencing */
 255         uint32_t                cmdsn;
 256         uint32_t                exp_cmdsn;
 257         uint32_t                max_cmdsn;
 258
 259         /* This tracks the reqs queued into the initiator */
 260         uint32_t                queued_cmdsn;
 261
 262         /* configuration */
 263         int                     abort_timeout;
 264         int                     lu_reset_timeout;
 265         int                     initial_r2t_en;
 266         unsigned                max_r2t;
 267         int                     imm_data_en;
 268         unsigned                first_burst;
 269         unsigned                max_burst;
 270         int                     time2wait;
 271         int                     time2retain;
 272         int                     pdu_inorder_en;
 273         int                     dataseq_inorder_en;
 274         int                     erl;
 275         int                     fast_abort;
 276         int                     tpgt;
 277         char                    *username;
 278         char                    *username_in;
 279         char                    *password;
 280         char                    *password_in;
 281         char                    *targetname;
 282         char                    *ifacename;
 283         char                    *initiatorname;
 284         /* control data */
 285         struct iscsi_transport  *tt;
 286         struct Scsi_Host        *host;
 287         struct iscsi_conn       *leadconn;      /* leading connection */
 288         spinlock_t              lock;           /* protects session state, *
 289                                                  * sequence numbers,       *
 290                                                  * session resources:      *
 291                                                  * - cmdpool,              *
 292                                                  * - mgmtpool,             *
 293                                                  * - r2tpool               */
 294         int                     state;          /* session state           */
 295         int                     age;            /* counts session re-opens */
 296
 297         int                     scsi_cmds_max;  /* max scsi commands */
 298         int                     cmds_max;       /* size of cmds array */
 299         struct iscsi_task       **cmds;         /* Original Cmds arr */
 300         struct iscsi_pool       cmdpool;        /* PDU's pool */
 301 };
 302
 303 enum {
 304         ISCSI_HOST_SETUP,
 305         ISCSI_HOST_REMOVED,
 306 };
 307
 308 struct iscsi_host {
 309         char                    *initiatorname;
 310         /* hw address or netdev iscsi connection is bound to */
 311         char                    *hwaddress;
 312         char                    *netdev;
 313         /* local address */
 314         int                     local_port;
 315         char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 316
 317         wait_queue_head_t       session_removal_wq;
 318         /* protects sessions and state */
 319         spinlock_t              lock;
 320         int                     num_sessions;
 321         int                     state;
 322
 323         struct workqueue_struct *workq;
 324         char                    workq_name[20];
 325 };
 326
 327 /*
 328  * scsi host template
 329  */
 330 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 331 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 332 extern int iscsi_eh_target_reset(struct scsi_cmnd *sc);
 333 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 334 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 335                               void (*done)(struct scsi_cmnd *));
 336
 337 /*
 338  * iSCSI host helpers.
 339  */
 340 #define iscsi_host_priv(_shost) \
 341         (shost_priv(_shost) + sizeof(struct iscsi_host))
 342
 343 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 344                                 enum iscsi_host_param param, char *buf,
 345                                 int buflen);
 346 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 347                                 enum iscsi_host_param param, char *buf);
 348 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 349 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 350                                           int dd_data_size,
 351                                           bool xmit_can_sleep);
 352 extern void iscsi_host_remove(struct Scsi_Host *shost);
 353 extern void iscsi_host_free(struct Scsi_Host *shost);
 354 extern int iscsi_target_alloc(struct scsi_target *starget);
 355
 356 /*
 357  * session management
 358  */
 359 extern struct iscsi_cls_session *
 360 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 361                     uint16_t, int, uint32_t, unsigned int);
 362 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 363 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 364 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 365                            enum iscsi_param param, char *buf, int buflen);
 366 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 367                                    enum iscsi_param param, char *buf);
 368
 369 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 370         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 371
 372 /*
 373  * connection management
 374  */
 375 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 376                                                int, uint32_t);
 377 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 378 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 379 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 380 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 381                            int);
 382 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 383 extern void iscsi_session_failure(struct iscsi_session *session,
 384                                   enum iscsi_err err);
 385 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 386                                 enum iscsi_param param, char *buf);
 387 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 388 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 389
 390 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 391         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 392                               fmt, ##a)
 393
 394 /*
 395  * pdu and task processing
 396  */
 397 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 398 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 399                                     struct iscsi_r2t_info *r2t,
 400                                     struct iscsi_data *hdr);
 401 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 402                                 char *, uint32_t);
 403 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 404                               char *, int);
 405 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 406                                 char *, int);
 407 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 408 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 409 extern void iscsi_requeue_task(struct iscsi_task *task);
 410 extern void iscsi_put_task(struct iscsi_task *task);
 411 extern void __iscsi_get_task(struct iscsi_task *task);
 412
 413 /*
 414  * generic helpers
 415  */
 416 extern void iscsi_pool_free(struct iscsi_pool *);
 417 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 418
 419 /*
 420  * inline functions to deal with padding.
 421  */
 422 static inline unsigned int
 423 iscsi_padded(unsigned int len)
 424 {
 425         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 426 }
 427
 428 static inline unsigned int
 429 iscsi_padding(unsigned int len)
 430 {
 431         len &= (ISCSI_PAD_LEN - 1);
 432         if (len)
 433                 len = ISCSI_PAD_LEN - len;
 434         return len;
 435 }
 436
 437 #endif