LXR qemu/backends/rng.c

   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#include "qemu/osdep.h"
  14#include "sysemu/rng.h"
  15#include "qapi/error.h"
  16#include "qapi/qmp/qerror.h"
  17#include "qemu/module.h"
  18#include "qom/object_interfaces.h"
  19
  20void rng_backend_request_entropy(RngBackend *s, size_t size,
  21                                 EntropyReceiveFunc *receive_entropy,
  22                                 void *opaque)
  23{
  24    RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  25    RngRequest *req;
  26
  27    if (k->request_entropy) {
  28        req = g_malloc(sizeof(*req));
  29
  30        req->offset = 0;
  31        req->size = size;
  32        req->receive_entropy = receive_entropy;
  33        req->opaque = opaque;
  34        req->data = g_malloc(req->size);
  35
  36        k->request_entropy(s, req);
  37
  38        QSIMPLEQ_INSERT_TAIL(&s->requests, req, next);
  39    }
  40}
  41
  42static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  43{
  44    RngBackend *s = RNG_BACKEND(obj);
  45
  46    return s->opened;
  47}
  48
  49static void rng_backend_complete(UserCreatable *uc, Error **errp)
  50{
  51    object_property_set_bool(OBJECT(uc), "opened", true, errp);
  52}
  53
  54static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
  55{
  56    RngBackend *s = RNG_BACKEND(obj);
  57    RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  58    Error *local_err = NULL;
  59
  60    if (value == s->opened) {
  61        return;
  62    }
  63
  64    if (!value && s->opened) {
  65        error_setg(errp, QERR_PERMISSION_DENIED);
  66        return;
  67    }
  68
  69    if (k->opened) {
  70        k->opened(s, &local_err);
  71        if (local_err) {
  72            error_propagate(errp, local_err);
  73            return;
  74        }
  75    }
  76
  77    s->opened = true;
  78}
  79
  80static void rng_backend_free_request(RngRequest *req)
  81{
  82    g_free(req->data);
  83    g_free(req);
  84}
  85
  86static void rng_backend_free_requests(RngBackend *s)
  87{
  88    RngRequest *req, *next;
  89
  90    QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) {
  91        rng_backend_free_request(req);
  92    }
  93
  94    QSIMPLEQ_INIT(&s->requests);
  95}
  96
  97void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
  98{
  99    QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next);
 100    rng_backend_free_request(req);
 101}
 102
 103static void rng_backend_init(Object *obj)
 104{
 105    RngBackend *s = RNG_BACKEND(obj);
 106
 107    QSIMPLEQ_INIT(&s->requests);
 108}
 109
 110static void rng_backend_finalize(Object *obj)
 111{
 112    RngBackend *s = RNG_BACKEND(obj);
 113
 114    rng_backend_free_requests(s);
 115}
 116
 117static void rng_backend_class_init(ObjectClass *oc, void *data)
 118{
 119    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 120
 121    ucc->complete = rng_backend_complete;
 122
 123    object_class_property_add_bool(oc, "opened",
 124                                   rng_backend_prop_get_opened,
 125                                   rng_backend_prop_set_opened);
 126}
 127
 128static const TypeInfo rng_backend_info = {
 129    .name = TYPE_RNG_BACKEND,
 130    .parent = TYPE_OBJECT,
 131    .instance_size = sizeof(RngBackend),
 132    .instance_init = rng_backend_init,
 133    .instance_finalize = rng_backend_finalize,
 134    .class_size = sizeof(RngBackendClass),
 135    .class_init = rng_backend_class_init,
 136    .abstract = true,
 137    .interfaces = (InterfaceInfo[]) {
 138        { TYPE_USER_CREATABLE },
 139        { }
 140    }
 141};
 142
 143static void register_types(void)
 144{
 145    type_register_static(&rng_backend_info);
 146}
 147
 148type_init(register_types);
 149