diff options
| -rw-r--r-- | Makefile.objs | 2 | ||||
| -rw-r--r-- | backends/Makefile.objs | 1 | ||||
| -rw-r--r-- | backends/rng.c | 93 | ||||
| -rw-r--r-- | include/qemu/rng.h | 93 |
4 files changed, 189 insertions, 0 deletions
diff --git a/Makefile.objs b/Makefile.objs index 37be7e26f7..dc1e699914 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -100,6 +100,8 @@ common-obj-y += vl.o common-obj-$(CONFIG_SLIRP) += slirp/ +common-obj-y += backends/ + ###################################################################### # libseccomp ifeq ($(CONFIG_SECCOMP),y) diff --git a/backends/Makefile.objs b/backends/Makefile.objs new file mode 100644 index 0000000000..06e08c782d --- /dev/null +++ b/backends/Makefile.objs @@ -0,0 +1 @@ +common-obj-y += rng.o diff --git a/backends/rng.c b/backends/rng.c new file mode 100644 index 0000000000..06f261180c --- /dev/null +++ b/backends/rng.c @@ -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. + */ + +#include "qemu/rng.h" +#include "qerror.h" + +void rng_backend_request_entropy(RngBackend *s, size_t size, + EntropyReceiveFunc *receive_entropy, + void *opaque) +{ + RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); + + if (k->request_entropy) { + k->request_entropy(s, size, receive_entropy, opaque); + } +} + +void rng_backend_cancel_requests(RngBackend *s) +{ + RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); + + if (k->cancel_requests) { + k->cancel_requests(s); + } +} + +static bool rng_backend_prop_get_opened(Object *obj, Error **errp) +{ + RngBackend *s = RNG_BACKEND(obj); + + return s->opened; +} + +void rng_backend_open(RngBackend *s, Error **errp) +{ + object_property_set_bool(OBJECT(s), true, "opened", errp); +} + +static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp) +{ + RngBackend *s = RNG_BACKEND(obj); + RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); + + if (value == s->opened) { + return; + } + + if (!value && s->opened) { + error_set(errp, QERR_PERMISSION_DENIED); + return; + } + + if (k->opened) { + k->opened(s, errp); + } + + if (!error_is_set(errp)) { + s->opened = value; + } +} + +static void rng_backend_init(Object *obj) +{ + object_property_add_bool(obj, "opened", + rng_backend_prop_get_opened, + rng_backend_prop_set_opened, + NULL); +} + +static TypeInfo rng_backend_info = { + .name = TYPE_RNG_BACKEND, + .parent = TYPE_OBJECT, + .instance_size = sizeof(RngBackend), + .instance_init = rng_backend_init, + .class_size = sizeof(RngBackendClass), + .abstract = true, +}; + +static void register_types(void) +{ + type_register_static(&rng_backend_info); +} + +type_init(register_types); diff --git a/include/qemu/rng.h b/include/qemu/rng.h new file mode 100644 index 0000000000..7e9d6723ff --- /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 |