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/mutex.h>
  28 #include <linux/timer.h>
  29 #include <linux/workqueue.h>
  30 #include <scsi/iscsi_proto.h>
  31 #include <scsi/iscsi_if.h>
  32
  33 struct scsi_transport_template;
  34 struct scsi_device;
  35 struct Scsi_Host;
  36 struct scsi_cmnd;
  37 struct socket;
  38 struct iscsi_transport;
  39 struct iscsi_cls_session;
  40 struct iscsi_cls_conn;
  41 struct iscsi_session;
  42 struct iscsi_nopin;
  43
  44 /* #define DEBUG_SCSI */
  45 #ifdef DEBUG_SCSI
  46 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
  47 #else
  48 #define debug_scsi(fmt...)
  49 #endif
  50
  51 #define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  52 #define ISCSI_MGMT_CMDS_MAX     16      /* must be power of 2 */
  53
  54 #define ISCSI_MGMT_ITT_OFFSET   0xa00
  55
  56 #define ISCSI_DEF_CMD_PER_LUN           32
  57 #define ISCSI_MAX_CMD_PER_LUN           128
  58
  59 /* Task Mgmt states */
  60 enum {
  61         TMF_INITIAL,
  62         TMF_QUEUED,
  63         TMF_SUCCESS,
  64         TMF_FAILED,
  65         TMF_TIMEDOUT,
  66         TMF_NOT_FOUND,
  67 };
  68
  69 /* Connection suspend "bit" */
  70 #define ISCSI_SUSPEND_BIT               1
  71
  72 #define ISCSI_ITT_MASK                  (0xfff)
  73 #define ISCSI_CID_SHIFT                 12
  74 #define ISCSI_CID_MASK                  (0xffff << ISCSI_CID_SHIFT)
  75 #define ISCSI_AGE_SHIFT                 28
  76 #define ISCSI_AGE_MASK                  (0xf << ISCSI_AGE_SHIFT)
  77
  78 #define ISCSI_ADDRESS_BUF_LEN           64
  79
  80 enum {
  81         /* this is the maximum possible storage for AHSs */
  82         ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  83                                 sizeof(struct iscsi_rlength_ahdr),
  84         ISCSI_DIGEST_SIZE = sizeof(__u32),
  85 };
  86
  87 struct iscsi_mgmt_task {
  88         /*
  89          * Becuae LLDs allocate their hdr differently, this is a pointer to
  90          * that storage. It must be setup at session creation time.
  91          */
  92         struct iscsi_hdr        *hdr;
  93         char                    *data;          /* mgmt payload */
  94         unsigned                data_count;     /* counts data to be sent */
  95         uint32_t                itt;            /* this ITT */
  96         void                    *dd_data;       /* driver/transport data */
  97         struct list_head        running;
  98 };
  99
 100 enum {
 101         ISCSI_TASK_COMPLETED,
 102         ISCSI_TASK_PENDING,
 103         ISCSI_TASK_RUNNING,
 104 };
 105
 106 struct iscsi_cmd_task {
 107         /*
 108          * Because LLDs allocate their hdr differently, this is a pointer
 109          * and length to that storage. It must be setup at session
 110          * creation time.
 111          */
 112         struct iscsi_cmd        *hdr;
 113         unsigned short          hdr_max;
 114         unsigned short          hdr_len;        /* accumulated size of hdr used */
 115         int                     itt;            /* this ITT */
 116
 117         uint32_t                unsol_datasn;
 118         unsigned                imm_count;      /* imm-data (bytes)   */
 119         unsigned                unsol_count;    /* unsolicited (bytes)*/
 120         /* offset in unsolicited stream (bytes); */
 121         unsigned                unsol_offset;
 122         unsigned                data_count;     /* remaining Data-Out */
 123         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 124         struct iscsi_conn       *conn;          /* used connection    */
 125
 126         /* state set/tested under session->lock */
 127         int                     state;
 128         atomic_t                refcount;
 129         struct list_head        running;        /* running cmd list */
 130         void                    *dd_data;       /* driver/transport data */
 131 };
 132
 133 static inline void* iscsi_next_hdr(struct iscsi_cmd_task *ctask)
 134 {
 135         return (void*)ctask->hdr + ctask->hdr_len;
 136 }
 137
 138 /* Connection's states */
 139 enum {
 140         ISCSI_CONN_INITIAL_STAGE,
 141         ISCSI_CONN_STARTED,
 142         ISCSI_CONN_STOPPED,
 143         ISCSI_CONN_CLEANUP_WAIT,
 144 };
 145
 146 struct iscsi_conn {
 147         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 148         void                    *dd_data;       /* iscsi_transport data */
 149         struct iscsi_session    *session;       /* parent session */
 150         /*
 151          * LLDs should set this lock. It protects the transport recv
 152          * code
 153          */
 154         rwlock_t                *recv_lock;
 155         /*
 156          * conn_stop() flag: stop to recover, stop to terminate
 157          */
 158         int                     stop_stage;
 159         struct timer_list       transport_timer;
 160         unsigned long           last_recv;
 161         unsigned long           last_ping;
 162         int                     ping_timeout;
 163         int                     recv_timeout;
 164         struct iscsi_mgmt_task  *ping_mtask;
 165
 166         /* iSCSI connection-wide sequencing */
 167         uint32_t                exp_statsn;
 168
 169         /* control data */
 170         int                     id;             /* CID */
 171         int                     c_stage;        /* connection state */
 172         /*
 173          * Preallocated buffer for pdus that have data but do not
 174          * originate from scsi-ml. We never have two pdus using the
 175          * buffer at the same time. It is only allocated to
 176          * the default max recv size because the pdus we support
 177          * should always fit in this buffer
 178          */
 179         char                    *data;
 180         struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
 181         struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
 182         struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
 183
 184         /* xmit */
 185         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 186         struct list_head        mgmt_run_list;  /* list of control tasks */
 187         struct list_head        xmitqueue;      /* data-path cmd queue */
 188         struct list_head        run_list;       /* list of cmds in progress */
 189         struct list_head        requeue;        /* tasks needing another run */
 190         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 191         unsigned long           suspend_tx;     /* suspend Tx */
 192         unsigned long           suspend_rx;     /* suspend Rx */
 193
 194         /* abort */
 195         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 196         struct iscsi_tm         tmhdr;
 197         struct timer_list       tmf_timer;
 198         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 199
 200         /* negotiated params */
 201         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 202         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 203         int                     hdrdgst_en;
 204         int                     datadgst_en;
 205         int                     ifmarker_en;
 206         int                     ofmarker_en;
 207         /* values userspace uses to id a conn */
 208         int                     persistent_port;
 209         char                    *persistent_address;
 210         /* remote portal currently connected to */
 211         int                     portal_port;
 212         char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 213         /* local address */
 214         int                     local_port;
 215         char                    local_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 };
 231
 232 struct iscsi_pool {
 233         struct kfifo            *queue;         /* FIFO Queue */
 234         void                    **pool;         /* Pool of elements */
 235         int                     max;            /* Max number of elements */
 236 };
 237
 238 /* Session's states */
 239 enum {
 240         ISCSI_STATE_FREE = 1,
 241         ISCSI_STATE_LOGGED_IN,
 242         ISCSI_STATE_FAILED,
 243         ISCSI_STATE_TERMINATE,
 244         ISCSI_STATE_IN_RECOVERY,
 245         ISCSI_STATE_RECOVERY_FAILED,
 246         ISCSI_STATE_LOGGING_OUT,
 247 };
 248
 249 struct iscsi_session {
 250         /*
 251          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 252          * task management functions. This must be taken before the session
 253          * and recv lock.
 254          */
 255         struct mutex            eh_mutex;
 256
 257         /* iSCSI session-wide sequencing */
 258         uint32_t                cmdsn;
 259         uint32_t                exp_cmdsn;
 260         uint32_t                max_cmdsn;
 261
 262         /* This tracks the reqs queued into the initiator */
 263         uint32_t                queued_cmdsn;
 264
 265         /* configuration */
 266         int                     abort_timeout;
 267         int                     lu_reset_timeout;
 268         int                     initial_r2t_en;
 269         unsigned                max_r2t;
 270         int                     imm_data_en;
 271         unsigned                first_burst;
 272         unsigned                max_burst;
 273         int                     time2wait;
 274         int                     time2retain;
 275         int                     pdu_inorder_en;
 276         int                     dataseq_inorder_en;
 277         int                     erl;
 278         int                     fast_abort;
 279         int                     tpgt;
 280         char                    *username;
 281         char                    *username_in;
 282         char                    *password;
 283         char                    *password_in;
 284         char                    *targetname;
 285         char                    *initiatorname;
 286         /* hw address or netdev iscsi connection is bound to */
 287         char                    *hwaddress;
 288         char                    *netdev;
 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                     cmds_max;       /* size of cmds array */
 303         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
 304         struct iscsi_pool       cmdpool;        /* PDU's pool */
 305         int                     mgmtpool_max;   /* size of mgmt array */
 306         struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
 307         struct iscsi_pool       mgmtpool;       /* Mgmt PDU's pool */
 308 };
 309
 310 /*
 311  * scsi host template
 312  */
 313 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 314 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 315 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
 316 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 317 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 318                               void (*done)(struct scsi_cmnd *));
 319
 320
 321 /*
 322  * iSCSI host helpers.
 323  */
 324 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 325                                 enum iscsi_host_param param, char *buf,
 326                                 int buflen);
 327 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 328                                 enum iscsi_host_param param, char *buf);
 329
 330 /*
 331  * session management
 332  */
 333 extern struct iscsi_cls_session *
 334 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
 335                     uint16_t, uint16_t, int, int, uint32_t, uint32_t *);
 336 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 337 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
 338 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 339 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 340                            enum iscsi_param param, char *buf, int buflen);
 341 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 342                                    enum iscsi_param param, char *buf);
 343
 344 #define session_to_cls(_sess) \
 345         hostdata_session(_sess->host->hostdata)
 346
 347 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 348         iscsi_cls_session_printk(prefix,                \
 349                 (struct iscsi_cls_session *)session_to_cls(_sess), fmt, ##a)
 350
 351 /*
 352  * connection management
 353  */
 354 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 355                                                uint32_t);
 356 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 357 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 358 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 359 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 360                            int);
 361 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 362 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 363                                 enum iscsi_param param, char *buf);
 364
 365 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 366         iscsi_cls_conn_printk(prefix, _c->cls_conn, fmt, ##a)
 367
 368 /*
 369  * pdu and task processing
 370  */
 371 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 372 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
 373                                         struct iscsi_data *hdr);
 374 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 375                                 char *, uint32_t);
 376 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 377                               char *, int);
 378 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
 379                             uint32_t *);
 380 extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
 381 extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
 382                                  struct iscsi_mgmt_task *mtask);
 383
 384 /*
 385  * generic helpers
 386  */
 387 extern void iscsi_pool_free(struct iscsi_pool *);
 388 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 389
 390 /*
 391  * inline functions to deal with padding.
 392  */
 393 static inline unsigned int
 394 iscsi_padded(unsigned int len)
 395 {
 396         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 397 }
 398
 399 static inline unsigned int
 400 iscsi_padding(unsigned int len)
 401 {
 402         len &= (ISCSI_PAD_LEN - 1);
 403         if (len)
 404                 len = ISCSI_PAD_LEN - len;
 405         return len;
 406 }
 407
 408 #endif