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author | Anthony Liguori <aliguori@us.ibm.com> | 2012-06-25 10:03:47 -0500 |
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committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-11-16 08:36:12 -0600 |
commit | a9b7b2ad7b075dba5495271706670e5c6b1304bc (patch) | |
tree | afb6265b0527f4c88aae906c69e079d97303d052 /include | |
parent | 0e5588438d921b8686bbf455f400f727b2ff7b62 (diff) | |
download | qemu-a9b7b2ad7b075dba5495271706670e5c6b1304bc.zip qemu-a9b7b2ad7b075dba5495271706670e5c6b1304bc.tar.gz qemu-a9b7b2ad7b075dba5495271706670e5c6b1304bc.tar.bz2 |
rng: add RndBackend abstract object class
This is the backend used by devices that need to request entropy.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/qemu/rng.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/include/qemu/rng.h b/include/qemu/rng.h new file mode 100644 index 0000000..7e9d672 --- /dev/null +++ b/include/qemu/rng.h @@ -0,0 +1,93 @@ +/* + * 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 "qemu/object.h" +#include "qemu-common.h" +#include "error.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 RngBackendClass RngBackendClass; +typedef struct RngBackend RngBackend; + +typedef void (EntropyReceiveFunc)(void *opaque, + const void *data, + size_t size); + +struct RngBackendClass +{ + ObjectClass parent_class; + + void (*request_entropy)(RngBackend *s, size_t size, + EntropyReceiveFunc *recieve_entropy, void *opaque); + void (*cancel_requests)(RngBackend *s); + + void (*opened)(RngBackend *s, Error **errp); +}; + +struct RngBackend +{ + Object parent; + + /*< protected >*/ + bool opened; +}; + +/** + * 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 appropriate. + * + * The backend does not need to pass the full amount of data to @receive_entropy + * but will pass at a value greater than 0. + */ +void rng_backend_request_entropy(RngBackend *s, size_t size, + EntropyReceiveFunc *receive_entropy, + void *opaque); + +/** + * rng_backend_cancel_requests: + * @s: the backend to cancel all pending requests in + * + * Cancels all pending requests submitted by @rng_backend_request_entropy. This + * should be used by a device during reset or in preparation for live migration + * to stop tracking any request. + */ +void rng_backend_cancel_requests(RngBackend *s); + +/** + * rng_backend_open: + * @s: the backend to open + * @errp: a pointer to return the #Error object if an error occurs. + * + * This function will open the backend if it is not already open. Calling this + * function on an already opened backend will not result in an error. + */ +void rng_backend_open(RngBackend *s, Error **errp); + +#endif |