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 struct iscsi_conn {
 139         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 140         void                    *dd_data;       /* iscsi_transport data */
 141         struct iscsi_session    *session;       /* parent session */
 142         /*
 143          * LLDs should set this lock. It protects the transport recv
 144          * code
 145          */
 146         rwlock_t                *recv_lock;
 147         /*
 148          * conn_stop() flag: stop to recover, stop to terminate
 149          */
 150         int                     stop_stage;
 151         struct timer_list       transport_timer;
 152         unsigned long           last_recv;
 153         unsigned long           last_ping;
 154         int                     ping_timeout;
 155         int                     recv_timeout;
 156         struct iscsi_mgmt_task  *ping_mtask;
 157
 158         /* iSCSI connection-wide sequencing */
 159         uint32_t                exp_statsn;
 160
 161         /* control data */
 162         int                     id;             /* CID */
 163         int                     c_stage;        /* connection state */
 164         /*
 165          * Preallocated buffer for pdus that have data but do not
 166          * originate from scsi-ml. We never have two pdus using the
 167          * buffer at the same time. It is only allocated to
 168          * the default max recv size because the pdus we support
 169          * should always fit in this buffer
 170          */
 171         char                    *data;
 172         struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
 173         struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
 174         struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
 175
 176         /* xmit */
 177         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 178         struct list_head        mgmt_run_list;  /* list of control tasks */
 179         struct list_head        xmitqueue;      /* data-path cmd queue */
 180         struct list_head        run_list;       /* list of cmds in progress */
 181         struct list_head        requeue;        /* tasks needing another run */
 182         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 183         unsigned long           suspend_tx;     /* suspend Tx */
 184         unsigned long           suspend_rx;     /* suspend Rx */
 185
 186         /* abort */
 187         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 188         struct iscsi_tm         tmhdr;
 189         struct timer_list       tmf_timer;
 190         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 191
 192         /* negotiated params */
 193         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 194         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 195         int                     hdrdgst_en;
 196         int                     datadgst_en;
 197         int                     ifmarker_en;
 198         int                     ofmarker_en;
 199         /* values userspace uses to id a conn */
 200         int                     persistent_port;
 201         char                    *persistent_address;
 202         /* remote portal currently connected to */
 203         int                     portal_port;
 204         char                    portal_address[ISCSI_ADDRESS_BUF_LEN];
 205         /* local address */
 206         int                     local_port;
 207         char                    local_address[ISCSI_ADDRESS_BUF_LEN];
 208
 209         /* MIB-statistics */
 210         uint64_t                txdata_octets;
 211         uint64_t                rxdata_octets;
 212         uint32_t                scsicmd_pdus_cnt;
 213         uint32_t                dataout_pdus_cnt;
 214         uint32_t                scsirsp_pdus_cnt;
 215         uint32_t                datain_pdus_cnt;
 216         uint32_t                r2t_pdus_cnt;
 217         uint32_t                tmfcmd_pdus_cnt;
 218         int32_t                 tmfrsp_pdus_cnt;
 219
 220         /* custom statistics */
 221         uint32_t                eh_abort_cnt;
 222 };
 223
 224 struct iscsi_pool {
 225         struct kfifo            *queue;         /* FIFO Queue */
 226         void                    **pool;         /* Pool of elements */
 227         int                     max;            /* Max number of elements */
 228 };
 229
 230 struct iscsi_session {
 231         /*
 232          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 233          * task management functions. This must be taken before the session
 234          * and recv lock.
 235          */
 236         struct mutex            eh_mutex;
 237
 238         /* iSCSI session-wide sequencing */
 239         uint32_t                cmdsn;
 240         uint32_t                exp_cmdsn;
 241         uint32_t                max_cmdsn;
 242
 243         /* This tracks the reqs queued into the initiator */
 244         uint32_t                queued_cmdsn;
 245
 246         /* configuration */
 247         int                     abort_timeout;
 248         int                     lu_reset_timeout;
 249         int                     initial_r2t_en;
 250         unsigned                max_r2t;
 251         int                     imm_data_en;
 252         unsigned                first_burst;
 253         unsigned                max_burst;
 254         int                     time2wait;
 255         int                     time2retain;
 256         int                     pdu_inorder_en;
 257         int                     dataseq_inorder_en;
 258         int                     erl;
 259         int                     fast_abort;
 260         int                     tpgt;
 261         char                    *username;
 262         char                    *username_in;
 263         char                    *password;
 264         char                    *password_in;
 265         char                    *targetname;
 266         char                    *initiatorname;
 267         /* hw address or netdev iscsi connection is bound to */
 268         char                    *hwaddress;
 269         char                    *netdev;
 270         /* control data */
 271         struct iscsi_transport  *tt;
 272         struct Scsi_Host        *host;
 273         struct iscsi_conn       *leadconn;      /* leading connection */
 274         spinlock_t              lock;           /* protects session state, *
 275                                                  * sequence numbers,       *
 276                                                  * session resources:      *
 277                                                  * - cmdpool,              *
 278                                                  * - mgmtpool,             *
 279                                                  * - r2tpool               */
 280         int                     state;          /* session state           */
 281         int                     age;            /* counts session re-opens */
 282
 283         int                     cmds_max;       /* size of cmds array */
 284         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
 285         struct iscsi_pool       cmdpool;        /* PDU's pool */
 286         int                     mgmtpool_max;   /* size of mgmt array */
 287         struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
 288         struct iscsi_pool       mgmtpool;       /* Mgmt PDU's pool */
 289 };
 290
 291 /*
 292  * scsi host template
 293  */
 294 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
 295 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 296 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
 297 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 298 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
 299                               void (*done)(struct scsi_cmnd *));
 300
 301
 302 /*
 303  * iSCSI host helpers.
 304  */
 305 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 306                                 enum iscsi_host_param param, char *buf,
 307                                 int buflen);
 308 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 309                                 enum iscsi_host_param param, char *buf);
 310
 311 /*
 312  * session management
 313  */
 314 extern struct iscsi_cls_session *
 315 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
 316                     uint16_t, uint16_t, int, int, uint32_t, uint32_t *);
 317 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 318 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
 319 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 320 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 321                            enum iscsi_param param, char *buf, int buflen);
 322 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 323                                    enum iscsi_param param, char *buf);
 324
 325 #define session_to_cls(_sess) \
 326         hostdata_session(_sess->host->hostdata)
 327
 328 /*
 329  * connection management
 330  */
 331 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 332                                                uint32_t);
 333 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 334 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 335 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 336 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 337                            int);
 338 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 339 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 340                                 enum iscsi_param param, char *buf);
 341
 342 /*
 343  * pdu and task processing
 344  */
 345 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 346 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
 347                                         struct iscsi_data *hdr);
 348 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 349                                 char *, uint32_t);
 350 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 351                               char *, int);
 352 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 353                                 char *, int);
 354 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
 355                             uint32_t *);
 356 extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
 357 extern void iscsi_free_mgmt_task(struct iscsi_conn *conn,
 358                                  struct iscsi_mgmt_task *mtask);
 359
 360 /*
 361  * generic helpers
 362  */
 363 extern void iscsi_pool_free(struct iscsi_pool *);
 364 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 365
 366 /*
 367  * inline functions to deal with padding.
 368  */
 369 static inline unsigned int
 370 iscsi_padded(unsigned int len)
 371 {
 372         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 373 }
 374
 375 static inline unsigned int
 376 iscsi_padding(unsigned int len)
 377 {
 378         len &= (ISCSI_PAD_LEN - 1);
 379         if (len)
 380                 len = ISCSI_PAD_LEN - len;
 381         return len;
 382 }
 383
 384 #endif