include/scsi/libiscsi.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * iSCSI lib definitions
   4  *
   5  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   6  * Copyright (C) 2004 - 2006 Mike Christie
   7  * Copyright (C) 2004 - 2005 Dmitry Yusupov
   8  * Copyright (C) 2004 - 2005 Alex Aizman
   9  */
  10 #ifndef LIBISCSI_H
  11 #define LIBISCSI_H
  12
  13 #include <linux/types.h>
  14 #include <linux/wait.h>
  15 #include <linux/mutex.h>
  16 #include <linux/timer.h>
  17 #include <linux/workqueue.h>
  18 #include <linux/kfifo.h>
  19 #include <linux/refcount.h>
  20 #include <scsi/iscsi_proto.h>
  21 #include <scsi/iscsi_if.h>
  22 #include <scsi/scsi_transport_iscsi.h>
  23
  24 struct scsi_transport_template;
  25 struct scsi_host_template;
  26 struct scsi_device;
  27 struct Scsi_Host;
  28 struct scsi_target;
  29 struct scsi_cmnd;
  30 struct socket;
  31 struct iscsi_transport;
  32 struct iscsi_cls_session;
  33 struct iscsi_cls_conn;
  34 struct iscsi_session;
  35 struct iscsi_nopin;
  36 struct device;
  37
  38 #define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  39 #define ISCSI_MGMT_CMDS_MAX     15
  40
  41 #define ISCSI_DEF_CMD_PER_LUN   32
  42
  43 /* Task Mgmt states */
  44 enum {
  45         TMF_INITIAL,
  46         TMF_QUEUED,
  47         TMF_SUCCESS,
  48         TMF_FAILED,
  49         TMF_TIMEDOUT,
  50         TMF_NOT_FOUND,
  51 };
  52
  53 #define ISID_SIZE                       6
  54
  55 /* Connection suspend "bit" */
  56 #define ISCSI_SUSPEND_BIT               1
  57
  58 #define ISCSI_ITT_MASK                  0x1fff
  59 #define ISCSI_TOTAL_CMDS_MAX            4096
  60 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  61 #define ISCSI_TOTAL_CMDS_MIN            16
  62 #define ISCSI_AGE_SHIFT                 28
  63 #define ISCSI_AGE_MASK                  0xf
  64
  65 #define ISCSI_ADDRESS_BUF_LEN           64
  66
  67 enum {
  68         /* this is the maximum possible storage for AHSs */
  69         ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  70                                 sizeof(struct iscsi_rlength_ahdr),
  71         ISCSI_DIGEST_SIZE = sizeof(__u32),
  72 };
  73
  74
  75 enum {
  76         ISCSI_TASK_FREE,
  77         ISCSI_TASK_COMPLETED,
  78         ISCSI_TASK_PENDING,
  79         ISCSI_TASK_RUNNING,
  80         ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
  81         ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
  82         ISCSI_TASK_REQUEUE_SCSIQ,       /* qcmd requeueing to scsi-ml */
  83 };
  84
  85 struct iscsi_r2t_info {
  86         __be32                  ttt;            /* copied from R2T */
  87         __be32                  exp_statsn;     /* copied from R2T */
  88         uint32_t                data_length;    /* copied from R2T */
  89         uint32_t                data_offset;    /* copied from R2T */
  90         int                     data_count;     /* DATA-Out payload progress */
  91         int                     datasn;
  92         /* LLDs should set/update these values */
  93         int                     sent;           /* R2T sequence progress */
  94 };
  95
  96 struct iscsi_task {
  97         /*
  98          * Because LLDs allocate their hdr differently, this is a pointer
  99          * and length to that storage. It must be setup at session
 100          * creation time.
 101          */
 102         struct iscsi_hdr        *hdr;
 103         unsigned short          hdr_max;
 104         unsigned short          hdr_len;        /* accumulated size of hdr used */
 105         /* copied values in case we need to send tmfs */
 106         itt_t                   hdr_itt;
 107         __be32                  cmdsn;
 108         struct scsi_lun         lun;
 109
 110         int                     itt;            /* this ITT */
 111
 112         unsigned                imm_count;      /* imm-data (bytes)   */
 113         /* offset in unsolicited stream (bytes); */
 114         struct iscsi_r2t_info   unsol_r2t;
 115         char                    *data;          /* mgmt payload */
 116         unsigned                data_count;
 117         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 118         struct iscsi_conn       *conn;          /* used connection    */
 119
 120         /* data processing tracking */
 121         unsigned long           last_xfer;
 122         unsigned long           last_timeout;
 123         bool                    have_checked_conn;
 124
 125         /* T10 protection information */
 126         bool                    protected;
 127
 128         /* state set/tested under session->lock */
 129         int                     state;
 130         refcount_t              refcount;
 131         struct list_head        running;        /* running cmd list */
 132         void                    *dd_data;       /* driver/transport data */
 133 };
 134
 135 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 136 {
 137         return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 138 }
 139
 140 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 141 {
 142         return (void*)task->hdr + task->hdr_len;
 143 }
 144
 145 /* Connection's states */
 146 enum {
 147         ISCSI_CONN_INITIAL_STAGE,
 148         ISCSI_CONN_STARTED,
 149         ISCSI_CONN_STOPPED,
 150         ISCSI_CONN_CLEANUP_WAIT,
 151 };
 152
 153 struct iscsi_conn {
 154         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 155         void                    *dd_data;       /* iscsi_transport data */
 156         struct iscsi_session    *session;       /* parent session */
 157         /*
 158          * conn_stop() flag: stop to recover, stop to terminate
 159          */
 160         int                     stop_stage;
 161         struct timer_list       transport_timer;
 162         unsigned long           last_recv;
 163         unsigned long           last_ping;
 164         int                     ping_timeout;
 165         int                     recv_timeout;
 166         struct iscsi_task       *ping_task;
 167
 168         /* iSCSI connection-wide sequencing */
 169         uint32_t                exp_statsn;
 170         uint32_t                statsn;
 171
 172         /* control data */
 173         int                     id;             /* CID */
 174         int                     c_stage;        /* connection state */
 175         /*
 176          * Preallocated buffer for pdus that have data but do not
 177          * originate from scsi-ml. We never have two pdus using the
 178          * buffer at the same time. It is only allocated to
 179          * the default max recv size because the pdus we support
 180          * should always fit in this buffer
 181          */
 182         char                    *data;
 183         struct iscsi_task       *login_task;    /* mtask used for login/text */
 184         struct iscsi_task       *task;          /* xmit task in progress */
 185
 186         /* xmit */
 187         spinlock_t              taskqueuelock;  /* protects the next three lists */
 188         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 189         struct list_head        cmdqueue;       /* data-path cmd queue */
 190         struct list_head        requeue;        /* tasks needing another run */
 191         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 192         unsigned long           suspend_tx;     /* suspend Tx */
 193         unsigned long           suspend_rx;     /* suspend Rx */
 194
 195         /* abort */
 196         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 197         struct iscsi_tm         tmhdr;
 198         struct timer_list       tmf_timer;
 199         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 200
 201         /* negotiated params */
 202         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 203         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 204         int                     hdrdgst_en;
 205         int                     datadgst_en;
 206         int                     ifmarker_en;
 207         int                     ofmarker_en;
 208         /* values userspace uses to id a conn */
 209         int                     persistent_port;
 210         char                    *persistent_address;
 211
 212         unsigned                max_segment_size;
 213         unsigned                tcp_xmit_wsf;
 214         unsigned                tcp_recv_wsf;
 215         uint16_t                keepalive_tmo;
 216         uint16_t                local_port;
 217         uint8_t                 tcp_timestamp_stat;
 218         uint8_t                 tcp_nagle_disable;
 219         uint8_t                 tcp_wsf_disable;
 220         uint8_t                 tcp_timer_scale;
 221         uint8_t                 tcp_timestamp_en;
 222         uint8_t                 fragment_disable;
 223         uint8_t                 ipv4_tos;
 224         uint8_t                 ipv6_traffic_class;
 225         uint8_t                 ipv6_flow_label;
 226         uint8_t                 is_fw_assigned_ipv6;
 227         char                    *local_ipaddr;
 228
 229         /* MIB-statistics */
 230         uint64_t                txdata_octets;
 231         uint64_t                rxdata_octets;
 232         uint32_t                scsicmd_pdus_cnt;
 233         uint32_t                dataout_pdus_cnt;
 234         uint32_t                scsirsp_pdus_cnt;
 235         uint32_t                datain_pdus_cnt;
 236         uint32_t                r2t_pdus_cnt;
 237         uint32_t                tmfcmd_pdus_cnt;
 238         int32_t                 tmfrsp_pdus_cnt;
 239
 240         /* custom statistics */
 241         uint32_t                eh_abort_cnt;
 242         uint32_t                fmr_unalign_cnt;
 243 };
 244
 245 struct iscsi_pool {
 246         struct kfifo            queue;          /* FIFO Queue */
 247         void                    **pool;         /* Pool of elements */
 248         int                     max;            /* Max number of elements */
 249 };
 250
 251 /* Session's states */
 252 enum {
 253         ISCSI_STATE_FREE = 1,
 254         ISCSI_STATE_LOGGED_IN,
 255         ISCSI_STATE_FAILED,
 256         ISCSI_STATE_TERMINATE,
 257         ISCSI_STATE_IN_RECOVERY,
 258         ISCSI_STATE_RECOVERY_FAILED,
 259         ISCSI_STATE_LOGGING_OUT,
 260 };
 261
 262 struct iscsi_session {
 263         struct iscsi_cls_session *cls_session;
 264         /*
 265          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 266          * task management functions. This must be taken before the session
 267          * and recv lock.
 268          */
 269         struct mutex            eh_mutex;
 270
 271         /* iSCSI session-wide sequencing */
 272         uint32_t                cmdsn;
 273         uint32_t                exp_cmdsn;
 274         uint32_t                max_cmdsn;
 275
 276         /* This tracks the reqs queued into the initiator */
 277         uint32_t                queued_cmdsn;
 278
 279         /* configuration */
 280         int                     abort_timeout;
 281         int                     lu_reset_timeout;
 282         int                     tgt_reset_timeout;
 283         int                     initial_r2t_en;
 284         unsigned short          max_r2t;
 285         int                     imm_data_en;
 286         unsigned                first_burst;
 287         unsigned                max_burst;
 288         int                     time2wait;
 289         int                     time2retain;
 290         int                     pdu_inorder_en;
 291         int                     dataseq_inorder_en;
 292         int                     erl;
 293         int                     fast_abort;
 294         int                     tpgt;
 295         char                    *username;
 296         char                    *username_in;
 297         char                    *password;
 298         char                    *password_in;
 299         char                    *targetname;
 300         char                    *targetalias;
 301         char                    *ifacename;
 302         char                    *initiatorname;
 303         char                    *boot_root;
 304         char                    *boot_nic;
 305         char                    *boot_target;
 306         char                    *portal_type;
 307         char                    *discovery_parent_type;
 308         uint16_t                discovery_parent_idx;
 309         uint16_t                def_taskmgmt_tmo;
 310         uint16_t                tsid;
 311         uint8_t                 auto_snd_tgt_disable;
 312         uint8_t                 discovery_sess;
 313         uint8_t                 chap_auth_en;
 314         uint8_t                 discovery_logout_en;
 315         uint8_t                 bidi_chap_en;
 316         uint8_t                 discovery_auth_optional;
 317         uint8_t                 isid[ISID_SIZE];
 318
 319         /* control data */
 320         struct iscsi_transport  *tt;
 321         struct Scsi_Host        *host;
 322         struct iscsi_conn       *leadconn;      /* leading connection */
 323         /* Between the forward and the backward locks exists a strict locking
 324          * hierarchy. The mutual exclusion zone protected by the forward lock
 325          * can enclose the mutual exclusion zone protected by the backward lock
 326          * but not vice versa.
 327          */
 328         spinlock_t              frwd_lock;      /* protects session state, *
 329                                                  * cmdsn, queued_cmdsn     *
 330                                                  * session resources:      *
 331                                                  * - cmdpool kfifo_out ,   *
 332                                                  * - mgmtpool,             */
 333         spinlock_t              back_lock;      /* protects cmdsn_exp      *
 334                                                  * cmdsn_max,              *
 335                                                  * cmdpool kfifo_in        */
 336         int                     state;          /* session state           */
 337         int                     age;            /* counts session re-opens */
 338
 339         int                     scsi_cmds_max;  /* max scsi commands */
 340         int                     cmds_max;       /* size of cmds array */
 341         struct iscsi_task       **cmds;         /* Original Cmds arr */
 342         struct iscsi_pool       cmdpool;        /* PDU's pool */
 343         void                    *dd_data;       /* LLD private data */
 344 };
 345
 346 enum {
 347         ISCSI_HOST_SETUP,
 348         ISCSI_HOST_REMOVED,
 349 };
 350
 351 struct iscsi_host {
 352         char                    *initiatorname;
 353         /* hw address or netdev iscsi connection is bound to */
 354         char                    *hwaddress;
 355         char                    *netdev;
 356
 357         wait_queue_head_t       session_removal_wq;
 358         /* protects sessions and state */
 359         spinlock_t              lock;
 360         int                     num_sessions;
 361         int                     state;
 362
 363         struct workqueue_struct *workq;
 364         char                    workq_name[20];
 365 };
 366
 367 /*
 368  * scsi host template
 369  */
 370 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 371 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 372 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 373 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 374 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 375 extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
 376
 377 /*
 378  * iSCSI host helpers.
 379  */
 380 #define iscsi_host_priv(_shost) \
 381         (shost_priv(_shost) + sizeof(struct iscsi_host))
 382
 383 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 384                                 enum iscsi_host_param param, char *buf,
 385                                 int buflen);
 386 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 387                                 enum iscsi_host_param param, char *buf);
 388 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 389 extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 390                                           int dd_data_size,
 391                                           bool xmit_can_sleep);
 392 extern void iscsi_host_remove(struct Scsi_Host *shost);
 393 extern void iscsi_host_free(struct Scsi_Host *shost);
 394 extern int iscsi_target_alloc(struct scsi_target *starget);
 395
 396 /*
 397  * session management
 398  */
 399 extern struct iscsi_cls_session *
 400 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 401                     uint16_t, int, int, uint32_t, unsigned int);
 402 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 403 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 404 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 405                            enum iscsi_param param, char *buf, int buflen);
 406 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 407                                    enum iscsi_param param, char *buf);
 408
 409 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 410         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 411
 412 /*
 413  * connection management
 414  */
 415 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 416                                                int, uint32_t);
 417 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 418 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 419 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 420 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 421                            int);
 422 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 423 extern void iscsi_session_failure(struct iscsi_session *session,
 424                                   enum iscsi_err err);
 425 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 426                                 enum iscsi_param param, char *buf);
 427 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 428                                      enum iscsi_param param, char *buf);
 429 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 430 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 431 extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 432
 433 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 434         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 435                               fmt, ##a)
 436
 437 /*
 438  * pdu and task processing
 439  */
 440 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 441 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 442                                     struct iscsi_r2t_info *r2t,
 443                                     struct iscsi_data *hdr);
 444 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 445                                 char *, uint32_t);
 446 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 447                               char *, int);
 448 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 449                                 char *, int);
 450 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 451 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 452 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 453 extern void iscsi_requeue_task(struct iscsi_task *task);
 454 extern void iscsi_put_task(struct iscsi_task *task);
 455 extern void __iscsi_put_task(struct iscsi_task *task);
 456 extern void __iscsi_get_task(struct iscsi_task *task);
 457 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 458                                      uint32_t exp_cmdsn, uint32_t max_cmdsn);
 459
 460 /*
 461  * generic helpers
 462  */
 463 extern void iscsi_pool_free(struct iscsi_pool *);
 464 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 465 extern int iscsi_switch_str_param(char **, char *);
 466
 467 /*
 468  * inline functions to deal with padding.
 469  */
 470 static inline unsigned int
 471 iscsi_padded(unsigned int len)
 472 {
 473         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 474 }
 475
 476 static inline unsigned int
 477 iscsi_padding(unsigned int len)
 478 {
 479         len &= (ISCSI_PAD_LEN - 1);
 480         if (len)
 481                 len = ISCSI_PAD_LEN - len;
 482         return len;
 483 }
 484
 485 #endif