/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * iSCSI transport class definitions
 *
 * Copyright (C) IBM Corporation, 2004
 * Copyright (C) Mike Christie, 2004 - 2006
 * Copyright (C) Dmitry Yusupov, 2004 - 2005
 * Copyright (C) Alex Aizman, 2004 - 2005
 */
#ifndef SCSI_TRANSPORT_ISCSI_H
#define SCSI_TRANSPORT_ISCSI_H

#include <linux/device.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <scsi/iscsi_if.h>

struct scsi_transport_template;
struct iscsi_transport;
struct iscsi_endpoint;
struct Scsi_Host;
struct scsi_cmnd;
struct iscsi_cls_conn;
struct iscsi_conn;
struct iscsi_task;
struct sockaddr;
struct iscsi_iface;
struct bsg_job;
struct iscsi_bus_flash_session;
struct iscsi_bus_flash_conn;

/**
 * struct iscsi_transport - iSCSI Transport template
 *
 * @name:               transport name
 * @caps:               iSCSI Data-Path capabilities
 * @create_session:     create new iSCSI session object
 * @destroy_session:    destroy existing iSCSI session object
 * @create_conn:        create new iSCSI connection
 * @bind_conn:          associate this connection with existing iSCSI session
 *                      and specified transport descriptor
 * @destroy_conn:       destroy inactive iSCSI connection
 * @set_param:          set iSCSI parameter. Return 0 on success, -ENODATA
 *                      when param is not supported, and a -Exx value on other
 *                      error.
 * @get_param           get iSCSI parameter. Must return number of bytes
 *                      copied to buffer on success, -ENODATA when param
 *                      is not supported, and a -Exx value on other error
 * @start_conn:         set connection to be operational
 * @stop_conn:          suspend/recover/terminate connection
 * @send_pdu:           send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
 * @session_recovery_timedout: notify LLD a block during recovery timed out
 * @init_task:          Initialize a iscsi_task and any internal structs.
 *                      When offloading the data path, this is called from
 *                      queuecommand with the session lock, or from the
 *                      iscsi_conn_send_pdu context with the session lock.
 *                      When not offloading the data path, this is called
 *                      from the scsi work queue without the session lock.
 * @xmit_task           Requests LLD to transfer cmd task. Returns 0 or the
 *                      number of bytes transferred on success, and -Exyz
 *                      value on error. When offloading the data path, this
 *                      is called from queuecommand with the session lock, or
 *                      from the iscsi_conn_send_pdu context with the session
 *                      lock. When not offloading the data path, this is called
 *                      from the scsi work queue without the session lock.
 * @cleanup_task:       requests LLD to fail task. Called with session lock
 *                      and after the connection has been suspended and
 *                      terminated during recovery. If called
 *                      from abort task then connection is not suspended
 *                      or terminated but sk_callback_lock is held
 *
 * Template API provided by iSCSI Transport
 */
struct iscsi_transport {
        struct module *owner;
        char *name;
        unsigned int caps;

        struct iscsi_cls_session *(*create_session) (struct iscsi_endpoint *ep,
                                        uint16_t cmds_max, uint16_t qdepth,
                                        uint32_t sn);
        void (*destroy_session) (struct iscsi_cls_session *session);
        struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
                                uint32_t cid);
        int (*bind_conn) (struct iscsi_cls_session *session,
                          struct iscsi_cls_conn *cls_conn,
                          uint64_t transport_eph, int is_leading);
        int (*start_conn) (struct iscsi_cls_conn *conn);
        void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
        void (*destroy_conn) (struct iscsi_cls_conn *conn);
        int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
                          char *buf, int buflen);
        int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
                             char *buf);
        int (*get_conn_param) (struct iscsi_cls_conn *conn,
                               enum iscsi_param param, char *buf);
        int (*get_session_param) (struct iscsi_cls_session *session,
                                  enum iscsi_param param, char *buf);
        int (*get_host_param) (struct Scsi_Host *shost,
                                enum iscsi_host_param param, char *buf);
        int (*set_host_param) (struct Scsi_Host *shost,
                               enum iscsi_host_param param, char *buf,
                               int buflen);
        int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
                         char *data, uint32_t data_size);
        void (*get_stats) (struct iscsi_cls_conn *conn,
                           struct iscsi_stats *stats);

        int (*init_task) (struct iscsi_task *task);
        int (*xmit_task) (struct iscsi_task *task);
        void (*cleanup_task) (struct iscsi_task *task);

        int (*alloc_pdu) (struct iscsi_task *task, uint8_t opcode);
        int (*xmit_pdu) (struct iscsi_task *task);
        int (*init_pdu) (struct iscsi_task *task, unsigned int offset,
                         unsigned int count);
        void (*parse_pdu_itt) (struct iscsi_conn *conn, itt_t itt,
                               int *index, int *age);

        void (*session_recovery_timedout) (struct iscsi_cls_session *session);
        struct iscsi_endpoint *(*ep_connect) (struct Scsi_Host *shost,
                                              struct sockaddr *dst_addr,
                                              int non_blocking);
        int (*ep_poll) (struct iscsi_endpoint *ep, int timeout_ms);
        void (*ep_disconnect) (struct iscsi_endpoint *ep);
        int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
                          uint32_t enable, struct sockaddr *dst_addr);
        int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
        int (*set_iface_param) (struct Scsi_Host *shost, void *data,
                                uint32_t len);
        int (*get_iface_param) (struct iscsi_iface *iface,
                                enum iscsi_param_type param_type,
                                int param, char *buf);
        umode_t (*attr_is_visible)(int param_type, int param);
        int (*bsg_request)(struct bsg_job *job);
        int (*send_ping) (struct Scsi_Host *shost, uint32_t iface_num,
                          uint32_t iface_type, uint32_t payload_size,
                          uint32_t pid, struct sockaddr *dst_addr);
        int (*get_chap) (struct Scsi_Host *shost, uint16_t chap_tbl_idx,
                         uint32_t *num_entries, char *buf);
        int (*delete_chap) (struct Scsi_Host *shost, uint16_t chap_tbl_idx);
        int (*set_chap) (struct Scsi_Host *shost, void *data, int len);
        int (*get_flashnode_param) (struct iscsi_bus_flash_session *fnode_sess,
                                    int param, char *buf);
        int (*set_flashnode_param) (struct iscsi_bus_flash_session *fnode_sess,
                                    struct iscsi_bus_flash_conn *fnode_conn,
                                    void *data, int len);
        int (*new_flashnode) (struct Scsi_Host *shost, const char *buf,
                              int len);
        int (*del_flashnode) (struct iscsi_bus_flash_session *fnode_sess);
        int (*login_flashnode) (struct iscsi_bus_flash_session *fnode_sess,
                                struct iscsi_bus_flash_conn *fnode_conn);
        int (*logout_flashnode) (struct iscsi_bus_flash_session *fnode_sess,
                                 struct iscsi_bus_flash_conn *fnode_conn);
        int (*logout_flashnode_sid) (struct iscsi_cls_session *cls_sess);
        int (*get_host_stats) (struct Scsi_Host *shost, char *buf, int len);
        u8 (*check_protection)(struct iscsi_task *task, sector_t *sector);
};

/*
 * transport registration upcalls
 */
extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
extern int iscsi_unregister_transport(struct iscsi_transport *tt);

/*
 * control plane upcalls
 */
extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
                                   enum iscsi_err error);
extern void iscsi_conn_login_event(struct iscsi_cls_conn *conn,
                                   enum iscsi_conn_state state);
extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
                          char *data, uint32_t data_size);

extern int iscsi_offload_mesg(struct Scsi_Host *shost,
                              struct iscsi_transport *transport, uint32_t type,
                              char *data, uint16_t data_size);

extern void iscsi_post_host_event(uint32_t host_no,
                                  struct iscsi_transport *transport,
                                  enum iscsi_host_event_code code,
                                  uint32_t data_size,
                                  uint8_t *data);

extern void iscsi_ping_comp_event(uint32_t host_no,
                                  struct iscsi_transport *transport,
                                  uint32_t status, uint32_t pid,
                                  uint32_t data_size, uint8_t *data);

/* iscsi class connection state */
enum iscsi_connection_state {
        ISCSI_CONN_UP = 0,
        ISCSI_CONN_DOWN,
        ISCSI_CONN_FAILED,
        ISCSI_CONN_BOUND,
};

struct iscsi_cls_conn {
        struct list_head conn_list;     /* item in connlist */
        struct list_head conn_list_err; /* item in connlist_err */
        void *dd_data;                  /* LLD private data */
        struct iscsi_transport *transport;
        uint32_t cid;                   /* connection id */
        struct mutex ep_mutex;
        struct iscsi_endpoint *ep;

        struct device dev;              /* sysfs transport/container device */
        enum iscsi_connection_state state;
};

#define iscsi_dev_to_conn(_dev) \
        container_of(_dev, struct iscsi_cls_conn, dev)

#define transport_class_to_conn(_cdev) \
        iscsi_dev_to_conn(_cdev->parent)

#define iscsi_conn_to_session(_conn) \
        iscsi_dev_to_session(_conn->dev.parent)

/* iscsi class session state */
enum {
        ISCSI_SESSION_LOGGED_IN,
        ISCSI_SESSION_FAILED,
        ISCSI_SESSION_FREE,
};

#define ISCSI_MAX_TARGET -1

struct iscsi_cls_session {
        struct list_head sess_list;             /* item in session_list */
        struct iscsi_transport *transport;
        spinlock_t lock;
        struct work_struct block_work;
        struct work_struct unblock_work;
        struct work_struct scan_work;
        struct work_struct unbind_work;
        struct work_struct destroy_work;

        /* recovery fields */
        int recovery_tmo;
        bool recovery_tmo_sysfs_override;
        struct delayed_work recovery_work;

        unsigned int target_id;
        bool ida_used;

        /*
         * pid of userspace process that created session or -1 if
         * created by the kernel.
         */
        pid_t creator;
        int state;
        int sid;                                /* session id */
        void *dd_data;                          /* LLD private data */
        struct device dev;      /* sysfs transport/container device */
};

#define iscsi_dev_to_session(_dev) \
        container_of(_dev, struct iscsi_cls_session, dev)

#define transport_class_to_session(_cdev) \
        iscsi_dev_to_session(_cdev->parent)

#define iscsi_session_to_shost(_session) \
        dev_to_shost(_session->dev.parent)

#define starget_to_session(_stgt) \
        iscsi_dev_to_session(_stgt->dev.parent)

struct iscsi_cls_host {
        atomic_t nr_scans;
        struct mutex mutex;
        struct request_queue *bsg_q;
        uint32_t port_speed;
        uint32_t port_state;
};

#define iscsi_job_to_shost(_job) \
        dev_to_shost(_job->dev)

extern void iscsi_host_for_each_session(struct Scsi_Host *shost,
                                void (*fn)(struct iscsi_cls_session *));

struct iscsi_endpoint {
        void *dd_data;                  /* LLD private data */
        struct device dev;
        uint64_t id;
        struct iscsi_cls_conn *conn;
};

struct iscsi_iface {
        struct device dev;
        struct iscsi_transport *transport;
        uint32_t iface_type;    /* IPv4 or IPv6 */
        uint32_t iface_num;     /* iface number, 0 - n */
        void *dd_data;          /* LLD private data */
};

#define iscsi_dev_to_iface(_dev) \
        container_of(_dev, struct iscsi_iface, dev)

#define iscsi_iface_to_shost(_iface) \
        dev_to_shost(_iface->dev.parent)


struct iscsi_bus_flash_conn {
        struct list_head conn_list;     /* item in connlist */
        void *dd_data;                  /* LLD private data */
        struct iscsi_transport *transport;
        struct device dev;              /* sysfs transport/container device */
        /* iscsi connection parameters */
        uint32_t                exp_statsn;
        uint32_t                statsn;
        unsigned                max_recv_dlength; /* initiator_max_recv_dsl*/
        unsigned                max_xmit_dlength; /* target_max_recv_dsl */
        unsigned                max_segment_size;
        unsigned                tcp_xmit_wsf;
        unsigned                tcp_recv_wsf;
        int                     hdrdgst_en;
        int                     datadgst_en;
        int                     port;
        char                    *ipaddress;
        char                    *link_local_ipv6_addr;
        char                    *redirect_ipaddr;
        uint16_t                keepalive_timeout;
        uint16_t                local_port;
        uint8_t                 snack_req_en;
        /* tcp timestamp negotiation status */
        uint8_t                 tcp_timestamp_stat;
        uint8_t                 tcp_nagle_disable;
        /* tcp window scale factor */
        uint8_t                 tcp_wsf_disable;
        uint8_t                 tcp_timer_scale;
        uint8_t                 tcp_timestamp_en;
        uint8_t                 ipv4_tos;
        uint8_t                 ipv6_traffic_class;
        uint8_t                 ipv6_flow_label;
        uint8_t                 fragment_disable;
        /* Link local IPv6 address is assigned by firmware or driver */
        uint8_t                 is_fw_assigned_ipv6;
};

#define iscsi_dev_to_flash_conn(_dev) \
        container_of(_dev, struct iscsi_bus_flash_conn, dev)

#define iscsi_flash_conn_to_flash_session(_conn) \
        iscsi_dev_to_flash_session(_conn->dev.parent)

#define ISID_SIZE 6

struct iscsi_bus_flash_session {
        struct list_head sess_list;             /* item in session_list */
        struct iscsi_transport *transport;
        unsigned int target_id;
        int flash_state;        /* persistent or non-persistent */
        void *dd_data;                          /* LLD private data */
        struct device dev;      /* sysfs transport/container device */
        /* iscsi session parameters */
        unsigned                first_burst;
        unsigned                max_burst;
        unsigned short          max_r2t;
        int                     default_taskmgmt_timeout;
        int                     initial_r2t_en;
        int                     imm_data_en;
        int                     time2wait;
        int                     time2retain;
        int                     pdu_inorder_en;
        int                     dataseq_inorder_en;
        int                     erl;
        int                     tpgt;
        char                    *username;
        char                    *username_in;
        char                    *password;
        char                    *password_in;
        char                    *targetname;
        char                    *targetalias;
        char                    *portal_type;
        uint16_t                tsid;
        uint16_t                chap_in_idx;
        uint16_t                chap_out_idx;
        /* index of iSCSI discovery session if the entry is
         * discovered by iSCSI discovery session
         */
        uint16_t                discovery_parent_idx;
        /* indicates if discovery was done through iSNS discovery service
         * or through sendTarget */
        uint16_t                discovery_parent_type;
        /* Firmware auto sendtarget discovery disable */
        uint8_t                 auto_snd_tgt_disable;
        uint8_t                 discovery_sess;
        /* indicates if this flashnode entry is enabled or disabled */
        uint8_t                 entry_state;
        uint8_t                 chap_auth_en;
        /* enables firmware to auto logout the discovery session on discovery
         * completion
         */
        uint8_t                 discovery_logout_en;
        uint8_t                 bidi_chap_en;
        /* makes authentication for discovery session optional */
        uint8_t                 discovery_auth_optional;
        uint8_t                 isid[ISID_SIZE];
        uint8_t                 is_boot_target;
};

#define iscsi_dev_to_flash_session(_dev) \
        container_of(_dev, struct iscsi_bus_flash_session, dev)

#define iscsi_flash_session_to_shost(_session) \
        dev_to_shost(_session->dev.parent)

/*
 * session and connection functions that can be used by HW iSCSI LLDs
 */
#define iscsi_cls_session_printk(prefix, _cls_session, fmt, a...) \
        dev_printk(prefix, &(_cls_session)->dev, fmt, ##a)

#define iscsi_cls_conn_printk(prefix, _cls_conn, fmt, a...) \
        dev_printk(prefix, &(_cls_conn)->dev, fmt, ##a)

extern int iscsi_session_chkready(struct iscsi_cls_session *session);
extern int iscsi_is_session_online(struct iscsi_cls_session *session);
extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
                                struct iscsi_transport *transport, int dd_size);
extern int iscsi_add_session(struct iscsi_cls_session *session,
                             unsigned int target_id);
extern int iscsi_session_event(struct iscsi_cls_session *session,
                               enum iscsi_uevent_e event);
extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
                                                struct iscsi_transport *t,
                                                int dd_size,
                                                unsigned int target_id);
extern void iscsi_remove_session(struct iscsi_cls_session *session);
extern void iscsi_free_session(struct iscsi_cls_session *session);
extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
                                                int dd_size, uint32_t cid);
extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
extern void iscsi_unblock_session(struct iscsi_cls_session *session);
extern void iscsi_block_session(struct iscsi_cls_session *session);
extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);
extern struct iscsi_endpoint *iscsi_create_endpoint(int dd_size);
extern void iscsi_destroy_endpoint(struct iscsi_endpoint *ep);
extern struct iscsi_endpoint *iscsi_lookup_endpoint(u64 handle);
extern int iscsi_block_scsi_eh(struct scsi_cmnd *cmd);
extern struct iscsi_iface *iscsi_create_iface(struct Scsi_Host *shost,
                                              struct iscsi_transport *t,
                                              uint32_t iface_type,
                                              uint32_t iface_num, int dd_size);
extern void iscsi_destroy_iface(struct iscsi_iface *iface);
extern struct iscsi_iface *iscsi_lookup_iface(int handle);
extern char *iscsi_get_port_speed_name(struct Scsi_Host *shost);
extern char *iscsi_get_port_state_name(struct Scsi_Host *shost);
extern int iscsi_is_session_dev(const struct device *dev);

extern char *iscsi_get_discovery_parent_name(int parent_type);
extern struct device *
iscsi_find_flashnode(struct Scsi_Host *shost, void *data,
                     int (*fn)(struct device *dev, void *data));

extern struct iscsi_bus_flash_session *
iscsi_create_flashnode_sess(struct Scsi_Host *shost, int index,
                            struct iscsi_transport *transport, int dd_size);

extern struct iscsi_bus_flash_conn *
iscsi_create_flashnode_conn(struct Scsi_Host *shost,
                            struct iscsi_bus_flash_session *fnode_sess,
                            struct iscsi_transport *transport, int dd_size);

extern void
iscsi_destroy_flashnode_sess(struct iscsi_bus_flash_session *fnode_sess);

extern void iscsi_destroy_all_flashnode(struct Scsi_Host *shost);
extern int iscsi_flashnode_bus_match(struct device *dev,
                                     struct device_driver *drv);
extern struct device *
iscsi_find_flashnode_sess(struct Scsi_Host *shost, void *data,
                          int (*fn)(struct device *dev, void *data));
extern struct device *
iscsi_find_flashnode_conn(struct iscsi_bus_flash_session *fnode_sess);

extern char *
iscsi_get_ipaddress_state_name(enum iscsi_ipaddress_state port_state);
extern char *iscsi_get_router_state_name(enum iscsi_router_state router_state);
#endif