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     Error *local_err = NULL;
  54
  55     if (value == s->opened) {
  56         return;
  57     }
  58
  59     if (!value && s->opened) {
  60         error_set(errp, QERR_PERMISSION_DENIED);
  61         return;
  62     }
  63
  64     if (k->opened) {
  65         k->opened(s, &local_err);
  66         if (local_err) {
  67             error_propagate(errp, local_err);
  68             return;
  69         }
  70     }
  71
  72     s->opened = true;
  73 }
  74
  75 static void rng_backend_init(Object *obj)
  76 {
  77     object_property_add_bool(obj, "opened",
  78                              rng_backend_prop_get_opened,
  79                              rng_backend_prop_set_opened,
  80                              NULL);
  81 }
  82
  83 static void rng_backend_class_init(ObjectClass *oc, void *data)
  84 {
  85     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
  86
  87     ucc->complete = rng_backend_complete;
  88 }
  89
  90 static const TypeInfo rng_backend_info = {
  91     .name = TYPE_RNG_BACKEND,
  92     .parent = TYPE_OBJECT,
  93     .instance_size = sizeof(RngBackend),
  94     .instance_init = rng_backend_init,
  95     .class_size = sizeof(RngBackendClass),
  96     .class_init = rng_backend_class_init,
  97     .abstract = true,
  98     .interfaces = (InterfaceInfo[]) {
  99         { TYPE_USER_CREATABLE },
 100         { }
 101     }
 102 };
 103
 104 static void register_types(void)
 105 {
 106     type_register_static(&rng_backend_info);
 107 }
 108
 109 type_init(register_types);