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_cmnd.h>
  23 #include <scsi/scsi_transport_iscsi.h>
  24
  25 struct scsi_transport_template;
  26 struct scsi_host_template;
  27 struct scsi_device;
  28 struct Scsi_Host;
  29 struct scsi_target;
  30 struct scsi_cmnd;
  31 struct socket;
  32 struct iscsi_transport;
  33 struct iscsi_cls_session;
  34 struct iscsi_cls_conn;
  35 struct iscsi_session;
  36 struct iscsi_nopin;
  37 struct device;
  38
  39 #define ISCSI_DEF_XMIT_CMDS_MAX 128     /* must be power of 2 */
  40 #define ISCSI_MGMT_CMDS_MAX     15
  41
  42 #define ISCSI_DEF_CMD_PER_LUN   32
  43
  44 /* Task Mgmt states */
  45 enum {
  46         TMF_INITIAL,
  47         TMF_QUEUED,
  48         TMF_SUCCESS,
  49         TMF_FAILED,
  50         TMF_TIMEDOUT,
  51         TMF_NOT_FOUND,
  52 };
  53
  54 #define ISID_SIZE                       6
  55
  56 /* Connection flags */
  57 #define ISCSI_CONN_FLAG_SUSPEND_TX      0
  58 #define ISCSI_CONN_FLAG_SUSPEND_RX      1
  59 #define ISCSI_CONN_FLAG_BOUND           2
  60
  61 #define ISCSI_ITT_MASK                  0x1fff
  62 #define ISCSI_TOTAL_CMDS_MAX            4096
  63 /* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
  64 #define ISCSI_TOTAL_CMDS_MIN            16
  65 #define ISCSI_AGE_SHIFT                 28
  66 #define ISCSI_AGE_MASK                  0xf
  67
  68 #define ISCSI_ADDRESS_BUF_LEN           64
  69
  70 enum {
  71         /* this is the maximum possible storage for AHSs */
  72         ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
  73                                 sizeof(struct iscsi_rlength_ahdr),
  74         ISCSI_DIGEST_SIZE = sizeof(__u32),
  75 };
  76
  77
  78 enum {
  79         ISCSI_TASK_FREE,
  80         ISCSI_TASK_COMPLETED,
  81         ISCSI_TASK_PENDING,
  82         ISCSI_TASK_RUNNING,
  83         ISCSI_TASK_ABRT_TMF,            /* aborted due to TMF */
  84         ISCSI_TASK_ABRT_SESS_RECOV,     /* aborted due to session recovery */
  85         ISCSI_TASK_REQUEUE_SCSIQ,       /* qcmd requeueing to scsi-ml */
  86 };
  87
  88 struct iscsi_r2t_info {
  89         __be32                  ttt;            /* copied from R2T */
  90         __be32                  exp_statsn;     /* copied from R2T */
  91         uint32_t                data_length;    /* copied from R2T */
  92         uint32_t                data_offset;    /* copied from R2T */
  93         int                     data_count;     /* DATA-Out payload progress */
  94         int                     datasn;
  95         /* LLDs should set/update these values */
  96         int                     sent;           /* R2T sequence progress */
  97 };
  98
  99 struct iscsi_task {
 100         /*
 101          * Because LLDs allocate their hdr differently, this is a pointer
 102          * and length to that storage. It must be setup at session
 103          * creation time.
 104          */
 105         struct iscsi_hdr        *hdr;
 106         unsigned short          hdr_max;
 107         unsigned short          hdr_len;        /* accumulated size of hdr used */
 108         /* copied values in case we need to send tmfs */
 109         itt_t                   hdr_itt;
 110         __be32                  cmdsn;
 111         struct scsi_lun         lun;
 112
 113         int                     itt;            /* this ITT */
 114
 115         unsigned                imm_count;      /* imm-data (bytes)   */
 116         /* offset in unsolicited stream (bytes); */
 117         struct iscsi_r2t_info   unsol_r2t;
 118         char                    *data;          /* mgmt payload */
 119         unsigned                data_count;
 120         struct scsi_cmnd        *sc;            /* associated SCSI cmd*/
 121         struct iscsi_conn       *conn;          /* used connection    */
 122
 123         /* data processing tracking */
 124         unsigned long           last_xfer;
 125         unsigned long           last_timeout;
 126         bool                    have_checked_conn;
 127
 128         /* T10 protection information */
 129         bool                    protected;
 130
 131         /* state set/tested under session->lock */
 132         int                     state;
 133         refcount_t              refcount;
 134         struct list_head        running;        /* running cmd list */
 135         void                    *dd_data;       /* driver/transport data */
 136 };
 137
 138 static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
 139 {
 140         return task->unsol_r2t.data_length > task->unsol_r2t.sent;
 141 }
 142
 143 static inline void* iscsi_next_hdr(struct iscsi_task *task)
 144 {
 145         return (void*)task->hdr + task->hdr_len;
 146 }
 147
 148 static inline bool iscsi_task_is_completed(struct iscsi_task *task)
 149 {
 150         return task->state == ISCSI_TASK_COMPLETED ||
 151                task->state == ISCSI_TASK_ABRT_TMF ||
 152                task->state == ISCSI_TASK_ABRT_SESS_RECOV;
 153 }
 154
 155 /* Private data associated with struct scsi_cmnd. */
 156 struct iscsi_cmd {
 157         struct iscsi_task       *task;
 158         int                     age;
 159 };
 160
 161 static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
 162 {
 163         return scsi_cmd_priv(cmd);
 164 }
 165
 166 /* Connection's states */
 167 enum {
 168         ISCSI_CONN_INITIAL_STAGE,
 169         ISCSI_CONN_STARTED,
 170         ISCSI_CONN_STOPPED,
 171         ISCSI_CONN_CLEANUP_WAIT,
 172 };
 173
 174 struct iscsi_conn {
 175         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 176         void                    *dd_data;       /* iscsi_transport data */
 177         struct iscsi_session    *session;       /* parent session */
 178         /*
 179          * conn_stop() flag: stop to recover, stop to terminate
 180          */
 181         int                     stop_stage;
 182         struct timer_list       transport_timer;
 183         unsigned long           last_recv;
 184         unsigned long           last_ping;
 185         int                     ping_timeout;
 186         int                     recv_timeout;
 187         struct iscsi_task       *ping_task;
 188
 189         /* iSCSI connection-wide sequencing */
 190         uint32_t                exp_statsn;
 191         uint32_t                statsn;
 192
 193         /* control data */
 194         int                     id;             /* CID */
 195         int                     c_stage;        /* connection state */
 196         /*
 197          * Preallocated buffer for pdus that have data but do not
 198          * originate from scsi-ml. We never have two pdus using the
 199          * buffer at the same time. It is only allocated to
 200          * the default max recv size because the pdus we support
 201          * should always fit in this buffer
 202          */
 203         char                    *data;
 204         struct iscsi_task       *login_task;    /* mtask used for login/text */
 205         struct iscsi_task       *task;          /* xmit task in progress */
 206
 207         /* xmit */
 208         /* items must be added/deleted under frwd lock */
 209         struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 210         struct list_head        cmdqueue;       /* data-path cmd queue */
 211         struct list_head        requeue;        /* tasks needing another run */
 212         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 213         /* recv */
 214         struct work_struct      recvwork;
 215         unsigned long           flags;          /* ISCSI_CONN_FLAGs */
 216
 217         /* negotiated params */
 218         unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 219         unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 220         int                     hdrdgst_en;
 221         int                     datadgst_en;
 222         int                     ifmarker_en;
 223         int                     ofmarker_en;
 224         /* values userspace uses to id a conn */
 225         int                     persistent_port;
 226         char                    *persistent_address;
 227
 228         unsigned                max_segment_size;
 229         unsigned                tcp_xmit_wsf;
 230         unsigned                tcp_recv_wsf;
 231         uint16_t                keepalive_tmo;
 232         uint16_t                local_port;
 233         uint8_t                 tcp_timestamp_stat;
 234         uint8_t                 tcp_nagle_disable;
 235         uint8_t                 tcp_wsf_disable;
 236         uint8_t                 tcp_timer_scale;
 237         uint8_t                 tcp_timestamp_en;
 238         uint8_t                 fragment_disable;
 239         uint8_t                 ipv4_tos;
 240         uint8_t                 ipv6_traffic_class;
 241         uint8_t                 ipv6_flow_label;
 242         uint8_t                 is_fw_assigned_ipv6;
 243         char                    *local_ipaddr;
 244
 245         /* MIB-statistics */
 246         uint64_t                txdata_octets;
 247         uint64_t                rxdata_octets;
 248         uint32_t                scsicmd_pdus_cnt;
 249         uint32_t                dataout_pdus_cnt;
 250         uint32_t                scsirsp_pdus_cnt;
 251         uint32_t                datain_pdus_cnt;
 252         uint32_t                r2t_pdus_cnt;
 253         uint32_t                tmfcmd_pdus_cnt;
 254         int32_t                 tmfrsp_pdus_cnt;
 255
 256         /* custom statistics */
 257         uint32_t                eh_abort_cnt;
 258         uint32_t                fmr_unalign_cnt;
 259 };
 260
 261 struct iscsi_pool {
 262         struct kfifo            queue;          /* FIFO Queue */
 263         void                    **pool;         /* Pool of elements */
 264         int                     max;            /* Max number of elements */
 265 };
 266
 267 /* Session's states */
 268 enum {
 269         ISCSI_STATE_FREE = 1,
 270         ISCSI_STATE_LOGGED_IN,
 271         ISCSI_STATE_FAILED,
 272         ISCSI_STATE_TERMINATE,
 273         ISCSI_STATE_IN_RECOVERY,
 274         ISCSI_STATE_RECOVERY_FAILED,
 275         ISCSI_STATE_LOGGING_OUT,
 276 };
 277
 278 struct iscsi_session {
 279         struct iscsi_cls_session *cls_session;
 280         /*
 281          * Syncs up the scsi eh thread with the iscsi eh thread when sending
 282          * task management functions. This must be taken before the session
 283          * and recv lock.
 284          */
 285         struct mutex            eh_mutex;
 286         /* abort */
 287         wait_queue_head_t       ehwait;         /* used in eh_abort() */
 288         struct iscsi_tm         tmhdr;
 289         struct timer_list       tmf_timer;
 290         int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 291         struct iscsi_task       *running_aborted_task;
 292
 293         /* iSCSI session-wide sequencing */
 294         uint32_t                cmdsn;
 295         uint32_t                exp_cmdsn;
 296         uint32_t                max_cmdsn;
 297
 298         /* This tracks the reqs queued into the initiator */
 299         uint32_t                queued_cmdsn;
 300
 301         /* configuration */
 302         int                     abort_timeout;
 303         int                     lu_reset_timeout;
 304         int                     tgt_reset_timeout;
 305         int                     initial_r2t_en;
 306         unsigned short          max_r2t;
 307         int                     imm_data_en;
 308         unsigned                first_burst;
 309         unsigned                max_burst;
 310         int                     time2wait;
 311         int                     time2retain;
 312         int                     pdu_inorder_en;
 313         int                     dataseq_inorder_en;
 314         int                     erl;
 315         int                     fast_abort;
 316         int                     tpgt;
 317         char                    *username;
 318         char                    *username_in;
 319         char                    *password;
 320         char                    *password_in;
 321         char                    *targetname;
 322         char                    *targetalias;
 323         char                    *ifacename;
 324         char                    *initiatorname;
 325         char                    *boot_root;
 326         char                    *boot_nic;
 327         char                    *boot_target;
 328         char                    *portal_type;
 329         char                    *discovery_parent_type;
 330         uint16_t                discovery_parent_idx;
 331         uint16_t                def_taskmgmt_tmo;
 332         uint16_t                tsid;
 333         uint8_t                 auto_snd_tgt_disable;
 334         uint8_t                 discovery_sess;
 335         uint8_t                 chap_auth_en;
 336         uint8_t                 discovery_logout_en;
 337         uint8_t                 bidi_chap_en;
 338         uint8_t                 discovery_auth_optional;
 339         uint8_t                 isid[ISID_SIZE];
 340
 341         /* control data */
 342         struct iscsi_transport  *tt;
 343         struct Scsi_Host        *host;
 344         struct iscsi_conn       *leadconn;      /* leading connection */
 345         /* Between the forward and the backward locks exists a strict locking
 346          * hierarchy. The mutual exclusion zone protected by the forward lock
 347          * can enclose the mutual exclusion zone protected by the backward lock
 348          * but not vice versa.
 349          */
 350         spinlock_t              frwd_lock;      /* protects session state, *
 351                                                  * cmdsn, queued_cmdsn     *
 352                                                  * session resources:      *
 353                                                  * - cmdpool kfifo_out ,   *
 354                                                  * - mgmtpool, queues      */
 355         spinlock_t              back_lock;      /* protects cmdsn_exp      *
 356                                                  * cmdsn_max,              *
 357                                                  * cmdpool kfifo_in        */
 358         int                     state;          /* session state           */
 359         int                     age;            /* counts session re-opens */
 360
 361         int                     scsi_cmds_max;  /* max scsi commands */
 362         int                     cmds_max;       /* size of cmds array */
 363         struct iscsi_task       **cmds;         /* Original Cmds arr */
 364         struct iscsi_pool       cmdpool;        /* PDU's pool */
 365         void                    *dd_data;       /* LLD private data */
 366 };
 367
 368 enum {
 369         ISCSI_HOST_SETUP,
 370         ISCSI_HOST_REMOVED,
 371 };
 372
 373 struct iscsi_host {
 374         char                    *initiatorname;
 375         /* hw address or netdev iscsi connection is bound to */
 376         char                    *hwaddress;
 377         char                    *netdev;
 378
 379         wait_queue_head_t       session_removal_wq;
 380         /* protects sessions and state */
 381         spinlock_t              lock;
 382         int                     num_sessions;
 383         int                     state;
 384
 385         struct workqueue_struct *workq;
 386 };
 387
 388 /*
 389  * scsi host template
 390  */
 391 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 392 extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 393 extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 394 extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 395 extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 396 extern enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
 397
 398 /*
 399  * iSCSI host helpers.
 400  */
 401 #define iscsi_host_priv(_shost) \
 402         (shost_priv(_shost) + sizeof(struct iscsi_host))
 403
 404 extern int iscsi_host_set_param(struct Scsi_Host *shost,
 405                                 enum iscsi_host_param param, char *buf,
 406                                 int buflen);
 407 extern int iscsi_host_get_param(struct Scsi_Host *shost,
 408                                 enum iscsi_host_param param, char *buf);
 409 extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 410 extern struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
 411                                           int dd_data_size,
 412                                           bool xmit_can_sleep);
 413 extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
 414 extern void iscsi_host_free(struct Scsi_Host *shost);
 415 extern int iscsi_target_alloc(struct scsi_target *starget);
 416 extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
 417                                         uint16_t requested_cmds_max);
 418
 419 /*
 420  * session management
 421  */
 422 extern struct iscsi_cls_session *
 423 iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 424                     uint16_t, int, int, uint32_t, unsigned int);
 425 void iscsi_session_remove(struct iscsi_cls_session *cls_session);
 426 void iscsi_session_free(struct iscsi_cls_session *cls_session);
 427 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 428 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 429 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 430                            enum iscsi_param param, char *buf, int buflen);
 431 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 432                                    enum iscsi_param param, char *buf);
 433
 434 #define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 435         iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 436
 437 /*
 438  * connection management
 439  */
 440 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 441                                                int, uint32_t);
 442 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 443 extern int iscsi_conn_start(struct iscsi_cls_conn *);
 444 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 445 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 446                            int);
 447 extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
 448 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 449 extern void iscsi_session_failure(struct iscsi_session *session,
 450                                   enum iscsi_err err);
 451 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 452                                 enum iscsi_param param, char *buf);
 453 extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 454                                      enum iscsi_param param, char *buf);
 455 extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 456 extern void iscsi_suspend_rx(struct iscsi_conn *conn);
 457 extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 458 extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
 459 extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
 460
 461 #define iscsi_conn_printk(prefix, _c, fmt, a...) \
 462         iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 463                               fmt, ##a)
 464
 465 /*
 466  * pdu and task processing
 467  */
 468 extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 469 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 470                                     struct iscsi_r2t_info *r2t,
 471                                     struct iscsi_data *hdr);
 472 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 473                                 char *, uint32_t);
 474 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 475                               char *, int);
 476 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 477                                 char *, int);
 478 extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 479 extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 480 extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 481 extern void iscsi_requeue_task(struct iscsi_task *task);
 482 extern void iscsi_put_task(struct iscsi_task *task);
 483 extern void __iscsi_put_task(struct iscsi_task *task);
 484 extern bool iscsi_get_task(struct iscsi_task *task);
 485 extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 486                                      uint32_t exp_cmdsn, uint32_t max_cmdsn);
 487
 488 /*
 489  * generic helpers
 490  */
 491 extern void iscsi_pool_free(struct iscsi_pool *);
 492 extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 493 extern int iscsi_switch_str_param(char **, char *);
 494
 495 /*
 496  * inline functions to deal with padding.
 497  */
 498 static inline unsigned int
 499 iscsi_padded(unsigned int len)
 500 {
 501         return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 502 }
 503
 504 static inline unsigned int
 505 iscsi_padding(unsigned int len)
 506 {
 507         len &= (ISCSI_PAD_LEN - 1);
 508         if (len)
 509                 len = ISCSI_PAD_LEN - len;
 510         return len;
 511 }
 512
 513 #endif