1 files changed, 89 insertions, 0 deletions
diff --git a/include/system/rng.h b/include/system/rng.h
new file mode 100644
index 0000000..e383f87
--- /dev/null
+++ b/include/system/rng.h
@@ -0,0 +1,89 @@
+/*
+ * 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/queue.h"
+#include "qom/object.h"
+
+#define TYPE_RNG_BACKEND "rng-backend"
+OBJECT_DECLARE_TYPE(RngBackend, RngBackendClass,
+                    RNG_BACKEND)
+
+#define TYPE_RNG_BUILTIN "rng-builtin"
+
+typedef struct RngRequest RngRequest;
+
+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(, 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