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
 135static 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
 140static inline void* iscsi_next_hdr(struct iscsi_task *task)
 141{
 142        return (void*)task->hdr + task->hdr_len;
 143}
 144
 145/* Connection's states */
 146enum {
 147        ISCSI_CONN_INITIAL_STAGE,
 148        ISCSI_CONN_STARTED,
 149        ISCSI_CONN_STOPPED,
 150        ISCSI_CONN_CLEANUP_WAIT,
 151};
 152
 153struct 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
 245struct 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 */
 252enum {
 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
 262struct 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
 346enum {
 347        ISCSI_HOST_SETUP,
 348        ISCSI_HOST_REMOVED,
 349};
 350
 351struct 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 */
 370extern int iscsi_eh_abort(struct scsi_cmnd *sc);
 371extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
 372extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
 373extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
 374extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
 375extern 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
 383extern int iscsi_host_set_param(struct Scsi_Host *shost,
 384                                enum iscsi_host_param param, char *buf,
 385                                int buflen);
 386extern int iscsi_host_get_param(struct Scsi_Host *shost,
 387                                enum iscsi_host_param param, char *buf);
 388extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
 389extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 390                                          int dd_data_size,
 391                                          bool xmit_can_sleep);
 392extern void iscsi_host_remove(struct Scsi_Host *shost);
 393extern void iscsi_host_free(struct Scsi_Host *shost);
 394extern int iscsi_target_alloc(struct scsi_target *starget);
 395
 396/*
 397 * session management
 398 */
 399extern struct iscsi_cls_session *
 400iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
 401                    uint16_t, int, int, uint32_t, unsigned int);
 402extern void iscsi_session_teardown(struct iscsi_cls_session *);
 403extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 404extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
 405                           enum iscsi_param param, char *buf, int buflen);
 406extern 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 */
 415extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
 416                                               int, uint32_t);
 417extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
 418extern int iscsi_conn_start(struct iscsi_cls_conn *);
 419extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
 420extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
 421                           int);
 422extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
 423extern void iscsi_session_failure(struct iscsi_session *session,
 424                                  enum iscsi_err err);
 425extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 426                                enum iscsi_param param, char *buf);
 427extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 428                                     enum iscsi_param param, char *buf);
 429extern void iscsi_suspend_tx(struct iscsi_conn *conn);
 430extern void iscsi_suspend_queue(struct iscsi_conn *conn);
 431extern 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 */
 440extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
 441extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 442                                    struct iscsi_r2t_info *r2t,
 443                                    struct iscsi_data *hdr);
 444extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
 445                                char *, uint32_t);
 446extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 447                              char *, int);
 448extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
 449                                char *, int);
 450extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
 451extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
 452extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
 453extern void iscsi_requeue_task(struct iscsi_task *task);
 454extern void iscsi_put_task(struct iscsi_task *task);
 455extern void __iscsi_put_task(struct iscsi_task *task);
 456extern void __iscsi_get_task(struct iscsi_task *task);
 457extern void iscsi_complete_scsi_task(struct iscsi_task *task,
 458                                     uint32_t exp_cmdsn, uint32_t max_cmdsn);
 459
 460/*
 461 * generic helpers
 462 */
 463extern void iscsi_pool_free(struct iscsi_pool *);
 464extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
 465extern int iscsi_switch_str_param(char **, char *);
 466
 467/*
 468 * inline functions to deal with padding.
 469 */
 470static inline unsigned int
 471iscsi_padded(unsigned int len)
 472{
 473        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
 474}
 475
 476static inline unsigned int
 477iscsi_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
 486