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 "sysemu/rng.h"
  14 #include "qapi/qmp/qerror.h"
  15 #include "qom/object_interfaces.h"
  16
  17 void rng_backend_request_entropy(RngBackend *s, size_t size,
  18                                  EntropyReceiveFunc *receive_entropy,
  19                                  void *opaque)
  20 {
  21     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  22
  23     if (k->request_entropy) {
  24         k->request_entropy(s, size, receive_entropy, opaque);
  25     }
  26 }
  27
  28 void rng_backend_cancel_requests(RngBackend *s)
  29 {
  30     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  31
  32     if (k->cancel_requests) {
  33         k->cancel_requests(s);
  34     }
  35 }
  36
  37 static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  38 {
  39     RngBackend *s = RNG_BACKEND(obj);
  40
  41     return s->opened;
  42 }
  43
  44 static void rng_backend_complete(UserCreatable *uc, Error **errp)
  45 {
  46     object_property_set_bool(OBJECT(uc), true, "opened", errp);
  47 }
  48
  49 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
  50 {
  51     RngBackend *s = RNG_BACKEND(obj);
  52     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  53
  54     if (value == s->opened) {
  55         return;
  56     }
  57
  58     if (!value && s->opened) {
  59         error_set(errp, QERR_PERMISSION_DENIED);
  60         return;
  61     }
  62
  63     if (k->opened) {
  64         k->opened(s, errp);
  65     }
  66
  67     if (!error_is_set(errp)) {
  68         s->opened = value;
  69     }
  70 }
  71
  72 static void rng_backend_init(Object *obj)
  73 {
  74     object_property_add_bool(obj, "opened",
  75                              rng_backend_prop_get_opened,
  76                              rng_backend_prop_set_opened,
  77                              NULL);
  78 }
  79
  80 static void rng_backend_class_init(ObjectClass *oc, void *data)
  81 {
  82     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
  83
  84     ucc->complete = rng_backend_complete;
  85 }
  86
  87 static const TypeInfo rng_backend_info = {
  88     .name = TYPE_RNG_BACKEND,
  89     .parent = TYPE_OBJECT,
  90     .instance_size = sizeof(RngBackend),
  91     .instance_init = rng_backend_init,
  92     .class_size = sizeof(RngBackendClass),
  93     .class_init = rng_backend_class_init,
  94     .abstract = true,
  95     .interfaces = (InterfaceInfo[]) {
  96         { TYPE_USER_CREATABLE },
  97         { }
  98     }
  99 };
 100
 101 static void register_types(void)
 102 {
 103     type_register_static(&rng_backend_info);
 104 }
 105
 106 type_init(register_types);