1 /* 2 * QEMU Random Number Generator Backend 3 * 4 * Copyright IBM, Corp. 2012 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 13 #ifndef QEMU_RNG_H 14 #define QEMU_RNG_H 15 16 #include "qom/object.h" 17 #include "qemu-common.h" 18 19 #define TYPE_RNG_BACKEND "rng-backend" 20 #define RNG_BACKEND(obj) \ 21 OBJECT_CHECK(RngBackend, (obj), TYPE_RNG_BACKEND) 22 #define RNG_BACKEND_GET_CLASS(obj) \ 23 OBJECT_GET_CLASS(RngBackendClass, (obj), TYPE_RNG_BACKEND) 24 #define RNG_BACKEND_CLASS(klass) \ 25 OBJECT_CLASS_CHECK(RngBackendClass, (klass), TYPE_RNG_BACKEND) 26 27 typedef struct RngBackendClass RngBackendClass; 28 typedef struct RngBackend RngBackend; 29 30 typedef void (EntropyReceiveFunc)(void *opaque, 31 const void *data, 32 size_t size); 33 34 struct RngBackendClass 35 { 36 ObjectClass parent_class; 37 38 void (*request_entropy)(RngBackend *s, size_t size, 39 EntropyReceiveFunc *receive_entropy, void *opaque); 40 41 void (*opened)(RngBackend *s, Error **errp); 42 }; 43 44 struct RngBackend 45 { 46 Object parent; 47 48 /*< protected >*/ 49 bool opened; 50 }; 51 52 /** 53 * rng_backend_request_entropy: 54 * @s: the backend to request entropy from 55 * @size: the number of bytes of data to request 56 * @receive_entropy: a function to be invoked when entropy is available 57 * @opaque: data that should be passed to @receive_entropy 58 * 59 * This function is used by the front-end to request entropy from an entropy 60 * source. This function can be called multiple times before @receive_entropy 61 * is invoked with different values of @receive_entropy and @opaque. The 62 * backend will queue each request and handle appropriately. 63 * 64 * The backend does not need to pass the full amount of data to @receive_entropy 65 * but will pass a value greater than 0. 66 */ 67 void rng_backend_request_entropy(RngBackend *s, size_t size, 68 EntropyReceiveFunc *receive_entropy, 69 void *opaque); 70 #endif 71