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