LXR linux/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
  24struct scsi_transport_template;
  25struct scsi_host_template;
  26struct scsi_device;
  27struct Scsi_Host;
  28struct scsi_target;
  29struct scsi_cmnd;
  30struct socket;
  31struct iscsi_transport;
  32struct iscsi_cls_session;
  33struct iscsi_cls_conn;
  34struct iscsi_session;
  35struct iscsi_nopin;
  36struct 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 */
  44enum {
  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
  67enum {
  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
  75enum {
  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
  85struct 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
  96struct 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/* invalid scsi_task pointer */
 136#define INVALID_SCSI_TASK       (struct iscsi_task *)-1l
 137
 138static 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
 143static inline void* iscsi_next_hdr(struct iscsi_task *task)
 144{
 145        return (void*)task->hdr + task->hdr_len;
 146}
 147
 148static 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/* Connection's states */
 156enum {
 157        ISCSI_CONN_INITIAL_STAGE,
 158        ISCSI_CONN_STARTED,
 159        ISCSI_CONN_STOPPED,
 160        ISCSI_CONN_CLEANUP_WAIT,
 161};
 162
 163struct iscsi_conn {
 164        struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
 165        void                    *dd_data;       /* iscsi_transport data */
 166        struct iscsi_session    *session;       /* parent session */
 167        /*
 168         * conn_stop() flag: stop to recover, stop to terminate
 169         */
 170        int                     stop_stage;
 171        struct timer_list       transport_timer;
 172        unsigned long           last_recv;
 173        unsigned long           last_ping;
 174        int                     ping_timeout;
 175        int                     recv_timeout;
 176        struct iscsi_task       *ping_task;
 177
 178        /* iSCSI connection-wide sequencing */
 179        uint32_t                exp_statsn;
 180        uint32_t                statsn;
 181
 182        /* control data */
 183        int                     id;             /* CID */
 184        int                     c_stage;        /* connection state */
 185        /*
 186         * Preallocated buffer for pdus that have data but do not
 187         * originate from scsi-ml. We never have two pdus using the
 188         * buffer at the same time. It is only allocated to
 189         * the default max recv size because the pdus we support
 190         * should always fit in this buffer
 191         */
 192        char                    *data;
 193        struct iscsi_task       *login_task;    /* mtask used for login/text */
 194        struct iscsi_task       *task;          /* xmit task in progress */
 195
 196        /* xmit */
 197        /* items must be added/deleted under frwd lock */
 198        struct list_head        mgmtqueue;      /* mgmt (control) xmit queue */
 199        struct list_head        cmdqueue;       /* data-path cmd queue */
 200        struct list_head        requeue;        /* tasks needing another run */
 201        struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 202        unsigned long           suspend_tx;     /* suspend Tx */
 203        unsigned long           suspend_rx;     /* suspend Rx */
 204
 205        /* negotiated params */
 206        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
 207        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
 208        int                     hdrdgst_en;
 209        int                     datadgst_en;
 210        int                     ifmarker_en;
 211        int                     ofmarker_en;
 212        /* values userspace uses to id a conn */
 213        int                     persistent_port;
 214        char                    *persistent_address;
 215
 216        unsigned                max_segment_size;
 217        unsigned                tcp_xmit_wsf;
 218        unsigned                tcp_recv_wsf;
 219        uint16_t                keepalive_tmo;
 220        uint16_t                local_port;
 221        uint8_t                 tcp_timestamp_stat;
 222        uint8_t                 tcp_nagle_disable;
 223        uint8_t                 tcp_wsf_disable;
 224        uint8_t                 tcp_timer_scale;
 225        uint8_t                 tcp_timestamp_en;
 226        uint8_t                 fragment_disable;
 227        uint8_t                 ipv4_tos;
 228        uint8_t                 ipv6_traffic_class;
 229        uint8_t                 ipv6_flow_label;
 230        uint8_t                 is_fw_assigned_ipv6;
 231        char                    *local_ipaddr;
 232
 233        /* MIB-statistics */
 234        uint64_t                txdata_octets;
 235        uint64_t                rxdata_octets;
 236        uint32_t                scsicmd_pdus_cnt;
 237        uint32_t                dataout_pdus_cnt;
 238        uint32_t                scsirsp_pdus_cnt;
 239        uint32_t                datain_pdus_cnt;
 240        uint32_t                r2t_pdus_cnt;
 241        uint32_t                tmfcmd_pdus_cnt;
 242        int32_t                 tmfrsp_pdus_cnt;
 243
 244        /* custom statistics */
 245        uint32_t                eh_abort_cnt;
 246        uint32_t                fmr_unalign_cnt;
 247};
 248
 249struct iscsi_pool {
 250        struct kfifo            queue;          /* FIFO Queue */
 251        void                    **pool;         /* Pool of elements */
 252        int                     max;            /* Max number of elements */
 253};
 254
 255/* Session's states */
 256enum {
 257        ISCSI_STATE_FREE = 1,
 258        ISCSI_STATE_LOGGED_IN,
 259        ISCSI_STATE_FAILED,
 260        ISCSI_STATE_TERMINATE,
 261        ISCSI_STATE_IN_RECOVERY,
 262        ISCSI_STATE_RECOVERY_FAILED,
 263        ISCSI_STATE_LOGGING_OUT,
 264};
 265
 266struct iscsi_session {
 267        struct iscsi_cls_session *cls_session;
 268        /*
 269         * Syncs up the scsi eh thread with the iscsi eh thread when sending
 270         * task management functions. This must be taken before the session
 271         * and recv lock.
 272         */
 273        struct mutex            eh_mutex;
 274        /* abort */
 275        wait_queue_head_t       ehwait;         /* used in eh_abort() */
 276        struct iscsi_tm         tmhdr;
 277        struct timer_list       tmf_timer;
 278        int                     tmf_state;      /* see TMF_INITIAL, etc.*/
 279        struct iscsi_task       *running_aborted_task;
 280
 281        /* iSCSI session-wide sequencing */
 282        uint32_t                cmdsn;
 283        uint32_t                exp_cmdsn;
 284        uint32_t                max_cmdsn;
 285
 286        /* This tracks the reqs queued into the initiator */
 287        uint32_t                queued_cmdsn;
 288
 289        /* configuration */
 290        int                     abort_timeout;
 291        int                     lu_reset_timeout;
 292        int                     tgt_reset_timeout;
 293        int                     initial_r2t_en;
 294        unsigned short          max_r2t;
 295        int                     imm_data_en;
 296        unsigned                first_burst;
 297        unsigned                max_burst;
 298        int                     time2wait;
 299        int                     time2retain;
 300        int                     pdu_inorder_en;
 301        int                     dataseq_inorder_en;
 302        int                     erl;
 303        int                     fast_abort;
 304        int                     tpgt;
 305        char                    *username;
 306        char                    *username_in;
 307        char                    *password;
 308        char                    *password_in;
 309        char                    *targetname;
 310        char                    *targetalias;
 311        char                    *ifacename;
 312        char                    *initiatorname;
 313        char                    *boot_root;
 314        char                    *boot_nic;
 315        char                    *boot_target;
 316        char                    *portal_type;
 317        char                    *discovery_parent_type;
 318        uint16_t                discovery_parent_idx;
 319        uint16_t                def_taskmgmt_tmo;
 320        uint16_t                tsid;
 321        uint8_t                 auto_snd_tgt_disable;
 322        uint8_t                 discovery_sess;
 323        uint8_t                 chap_auth_en;
 324        uint8_t                 discovery_logout_en;
 325        uint8_t                 bidi_chap_en;
 326        uint8_t                 discovery_auth_optional;
 327        uint8_t                 isid[ISID_SIZE];
 328
 329        /* control data */
 330        struct iscsi_transport  *tt;
 331        struct Scsi_Host        *host;
 332        struct iscsi_conn       *leadconn;      /* leading connection */
 333        /* Between the forward and the backward locks exists a strict locking
 334         * hierarchy. The mutual exclusion zone protected by the forward lock
 335         * can enclose the mutual exclusion zone protected by the backward lock
 336         * but not vice versa.
 337         */
 338        spinlock_t              frwd_lock;      /* protects session state, *
 339                                                 * cmdsn, queued_cmdsn     *
 340                                                 * session resources:      *
 341                                                 * - cmdpool kfifo_out ,   *
 342                                                 * - mgmtpool, queues      */
 343        spinlock_t              back_lock;      /* protects cmdsn_exp      *
 344                                                 * cmdsn_max,              *
 345                                                 * cmdpool kfifo_in        */
 346        int                     state;          /* session state           */
 347        int                     age;            /* counts session re-opens */
 348
 349        int                     scsi_cmds_max;  /* max scsi commands */
 350        int                     cmds_max;       /* size of cmds array */
 351        struct iscsi_task       **cmds;         /* Original Cmds arr */
 352        struct iscsi_pool       cmdpool;        /* PDU's pool */
 353        void                    *dd_data;       /* LLD private data */
 354};
 355
 356enum {
 357        ISCSI_HOST_SETUP,
 358        ISCSI_HOST_REMOVED,
 359};
 360
 361struct iscsi_host {
 362        char                    *initiatorname;
 363        /* hw address or netdev iscsi connection is bound to */
 364        char                    *hwaddress;
 365        char                    *netdev;
 366
 367        wait_queue_head_t       session_removal_wq;
 368        /* protects sessions and state */
 369        spinlock_t              lock;
 370        int                     num_sessions;
 371        int                     state;
 372
 373        struct workqueue_struct *workq;
 374        char                    workq_name[20];
 375};
 376
 377/*
 378 * scsi host template
 379 */
 380extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 381extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 382extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 383extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 384extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 385extern enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
 386
 387/*
 388 * iSCSI host helpers.
 389 */
 390#define iscsi_host_priv(_shost) \
 391        (shost_priv(_shost) + sizeof(struct iscsi_host))
 392
 393extern int iscsi_host_set_param(struct Scsi_Host *shost,
 394                                enum iscsi_host_param param, char *buf,
 395                                int buflen);
 396extern int iscsi_host_get_param(struct Scsi_Host *shost,
 397                                enum iscsi_host_param param, char *buf);
 398extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 399extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 400                                          int dd_data_size,
 401                                          bool xmit_can_sleep);
 402extern void iscsi_host_remove(struct Scsi_Host *shost);
 403extern void iscsi_host_free(struct Scsi_Host *shost);
 404extern int iscsi_target_alloc(struct scsi_target *starget);
 405extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
 406                                        uint16_t requested_cmds_max);
 407
 408/*
 409 * session management
 410 */
 411extern struct iscsi_cls_session *
 412iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 413                    uint16_t, int, int, uint32_t, unsigned int);
 414extern void iscsi_session_teardown(struct iscsi_cls_session *);
 415extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 416extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 417                           enum iscsi_param param, char *buf, int buflen);
 418extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 419                                   enum iscsi_param param, char *buf);
 420
 421#define iscsi_session_printk(prefix, _sess, fmt, a...)  \
 422        iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
 423
 424/*
 425 * connection management
 426 */
 427extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 428                                               int, uint32_t);
 429extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 430extern int iscsi_conn_start(struct iscsi_cls_conn *);
 431extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 432extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 433                           int);
 434extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
 435extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 436extern void iscsi_session_failure(struct iscsi_session *session,
 437                                  enum iscsi_err err);
 438extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 439                                enum iscsi_param param, char *buf);
 440extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 441                                     enum iscsi_param param, char *buf);
 442extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 443extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 444extern void iscsi_conn_queue_work(struct iscsi_conn *conn);
 445
 446#define iscsi_conn_printk(prefix, _c, fmt, a...) \
 447        iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
 448                              fmt, ##a)
 449
 450/*
 451 * pdu and task processing
 452 */
 453extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 454extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 455                                    struct iscsi_r2t_info *r2t,
 456                                    struct iscsi_data *hdr);
 457extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 458                                char *, uint32_t);
 459extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 460                              char *, int);
 461extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 462                                char *, int);
 463extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 464extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 465extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 466extern void iscsi_requeue_task(struct iscsi_task *task);
 467extern void iscsi_put_task(struct iscsi_task *task);
 468extern void __iscsi_put_task(struct iscsi_task *task);
 469extern void __iscsi_get_task(struct iscsi_task *task);
 470extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 471                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);
 472
 473/*
 474 * generic helpers
 475 */
 476extern void iscsi_pool_free(struct iscsi_pool *);
 477extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 478extern int iscsi_switch_str_param(char **, char *);
 479
 480/*
 481 * inline functions to deal with padding.
 482 */
 483static inline unsigned int
 484iscsi_padded(unsigned int len)
 485{
 486        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 487}
 488
 489static inline unsigned int
 490iscsi_padding(unsigned int len)
 491{
 492        len &= (ISCSI_PAD_LEN - 1);
 493        if (len)
 494                len = ISCSI_PAD_LEN - len;
 495        return len;
 496}
 497
 498#endif
 499