qemu/include/sysemu/rng.h

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/*
* QEMU Random Number Generator Backend
*
* Copyright IBM, Corp. 2012
*
* Authors:
* Anthony Liguori <aliguori@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 QEMU_RNG_H
#define QEMU_RNG_H
#include "qom/object.h"
#include "qemu-common.h"
#define TYPE_RNG_BACKEND "rng-backend"
#define RNG_BACKEND(obj) \
OBJECT_CHECK(RngBackend, (obj), TYPE_RNG_BACKEND)
#define RNG_BACKEND_GET_CLASS(obj) \
OBJECT_GET_CLASS(RngBackendClass, (obj), TYPE_RNG_BACKEND)
#define RNG_BACKEND_CLASS(klass) \
OBJECT_CLASS_CHECK(RngBackendClass, (klass), TYPE_RNG_BACKEND)
typedef struct RngRequest RngRequest;
typedef struct RngBackendClass RngBackendClass;
typedef struct RngBackend RngBackend;
typedef void (EntropyReceiveFunc)(void *opaque,
const void *data,
size_t size);
struct RngRequest
{
EntropyReceiveFunc *receive_entropy;
uint8_t *data;
void *opaque;
size_t offset;
size_t size;
QSIMPLEQ_ENTRY(RngRequest) next;
};
struct RngBackendClass
{
ObjectClass parent_class;
void (*request_entropy)(RngBackend *s, RngRequest *req);
void (*opened)(RngBackend *s, Error **errp);
};
struct RngBackend
{
Object parent;
/*< protected >*/
bool opened;
QSIMPLEQ_HEAD(requests, RngRequest) requests;
};
/**
* rng_backend_request_entropy:
* @s: the backend to request entropy from
* @size: the number of bytes of data to request
* @receive_entropy: a function to be invoked when entropy is available
* @opaque: data that should be passed to @receive_entropy
*
* This function is used by the front-end to request entropy from an entropy
* source. This function can be called multiple times before @receive_entropy
* is invoked with different values of @receive_entropy and @opaque. The
* backend will queue each request and handle appropriately.
*
* The backend does not need to pass the full amount of data to @receive_entropy
* but will pass a value greater than 0.
*/
void rng_backend_request_entropy(RngBackend *s, size_t size,
EntropyReceiveFunc *receive_entropy,
void *opaque);
/**
* rng_backend_free_request:
* @s: the backend that created the request
* @req: the request to finalize
*
* Used by child rng backend classes to finalize requests once they've been
* processed. The request is removed from the list of active requests and
* deleted.
*/
void rng_backend_finalize_request(RngBackend *s, RngRequest *req);
#endif