/*
 * QEMU TPM Backend
 *
 * Copyright IBM, Corp. 2013
 *
 * Authors:
 *  Stefan Berger  <stefanb@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#ifndef TPM_BACKEND_H
#define TPM_BACKEND_H

#include "qom/object.h"
#include "qemu/option.h"
#include "sysemu/tpm.h"
#include "qapi/error.h"

#define TYPE_TPM_BACKEND "tpm-backend"
#define TPM_BACKEND(obj) \
    OBJECT_CHECK(TPMBackend, (obj), TYPE_TPM_BACKEND)
#define TPM_BACKEND_GET_CLASS(obj) \
    OBJECT_GET_CLASS(TPMBackendClass, (obj), TYPE_TPM_BACKEND)
#define TPM_BACKEND_CLASS(klass) \
    OBJECT_CLASS_CHECK(TPMBackendClass, (klass), TYPE_TPM_BACKEND)

typedef struct TPMBackendClass TPMBackendClass;
typedef struct TPMBackend TPMBackend;

typedef struct TPMBackendCmd {
    uint8_t locty;
    const uint8_t *in;
    uint32_t in_len;
    uint8_t *out;
    uint32_t out_len;
    bool selftest_done;
} TPMBackendCmd;

struct TPMBackend {
    Object parent;

    /*< protected >*/
    TPMIf *tpmif;
    bool opened;
    bool had_startup_error;
    TPMBackendCmd *cmd;

    /* <public> */
    char *id;

    QLIST_ENTRY(TPMBackend) list;
};

struct TPMBackendClass {
    ObjectClass parent_class;

    enum TpmType type;
    const QemuOptDesc *opts;
    /* get a descriptive text of the backend to display to the user */
    const char *desc;

    TPMBackend *(*create)(QemuOpts *opts);

    /* start up the TPM on the backend - optional */
    int (*startup_tpm)(TPMBackend *t, size_t buffersize);

    /* optional */
    void (*reset)(TPMBackend *t);

    void (*cancel_cmd)(TPMBackend *t);

    /* optional */
    bool (*get_tpm_established_flag)(TPMBackend *t);

    /* optional */
    int (*reset_tpm_established_flag)(TPMBackend *t, uint8_t locty);

    TPMVersion (*get_tpm_version)(TPMBackend *t);

    size_t (*get_buffer_size)(TPMBackend *t);

    TpmTypeOptions *(*get_tpm_options)(TPMBackend *t);

    void (*handle_request)(TPMBackend *s, TPMBackendCmd *cmd, Error **errp);
};

/**
 * tpm_backend_get_type:
 * @s: the backend
 *
 * Returns the TpmType of the backend.
 */
enum TpmType tpm_backend_get_type(TPMBackend *s);

/**
 * tpm_backend_init:
 * @s: the backend to initialized
 * @tpmif: TPM interface
 * @datacb: callback for sending data to frontend
 * @errp: a pointer to return the #Error object if an error occurs.
 *
 * Initialize the backend with the given variables.
 *
 * Returns 0 on success.
 */
int tpm_backend_init(TPMBackend *s, TPMIf *tpmif, Error **errp);

/**
 * tpm_backend_startup_tpm:
 * @s: the backend whose TPM support is to be started
 * @buffersize: the buffer size the TPM is supposed to use,
 *              0 to leave it as-is
 *
 * Returns 0 on success.
 */
int tpm_backend_startup_tpm(TPMBackend *s, size_t buffersize);

/**
 * tpm_backend_had_startup_error:
 * @s: the backend to query for a statup error
 *
 * Check whether the backend had an error during startup. Returns
 * false if no error occurred and the backend can be used, true
 * otherwise.
 */
bool tpm_backend_had_startup_error(TPMBackend *s);

/**
 * tpm_backend_deliver_request:
 * @s: the backend to send the request to
 * @cmd: the command to deliver
 *
 * Send a request to the backend. The backend will then send the request
 * to the TPM implementation.
 */
void tpm_backend_deliver_request(TPMBackend *s, TPMBackendCmd *cmd);

/**
 * tpm_backend_reset:
 * @s: the backend to reset
 *
 * Reset the backend into a well defined state with all previous errors
 * reset.
 */
void tpm_backend_reset(TPMBackend *s);

/**
 * tpm_backend_cancel_cmd:
 * @s: the backend
 *
 * Cancel any ongoing command being processed by the TPM implementation
 * on behalf of the QEMU guest.
 */
void tpm_backend_cancel_cmd(TPMBackend *s);

/**
 * tpm_backend_get_tpm_established_flag:
 * @s: the backend
 *
 * Get the TPM establishment flag. This function may be called very
 * frequently by the frontend since for example in the TIS implementation
 * this flag is part of a register.
 */
bool tpm_backend_get_tpm_established_flag(TPMBackend *s);

/**
 * tpm_backend_reset_tpm_established_flag:
 * @s: the backend
 * @locty: the locality number
 *
 * Reset the TPM establishment flag.
 */
int tpm_backend_reset_tpm_established_flag(TPMBackend *s, uint8_t locty);

/**
 * tpm_backend_get_tpm_version:
 * @s: the backend to call into
 *
 * Get the TPM Version that is emulated at the backend.
 *
 * Returns TPMVersion.
 */
TPMVersion tpm_backend_get_tpm_version(TPMBackend *s);

/**
 * tpm_backend_get_buffer_size:
 * @s: the backend to call into
 *
 * Get the TPM's buffer size.
 *
 * Returns buffer size.
 */
size_t tpm_backend_get_buffer_size(TPMBackend *s);

/**
 * tpm_backend_finish_sync:
 * @s: the backend to call into
 *
 * Finish the pending command synchronously (this will call aio_poll()
 * on qemu main AIOContext until it ends)
 */
void tpm_backend_finish_sync(TPMBackend *s);

/**
 * tpm_backend_query_tpm:
 * @s: the backend
 *
 * Query backend tpm info
 *
 * Returns newly allocated TPMInfo
 */
TPMInfo *tpm_backend_query_tpm(TPMBackend *s);

TPMBackend *qemu_find_tpm_be(const char *id);

#endif