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/qmp/qerror.h"
  16 #include "qom/object_interfaces.h"
  17
  18 void rng_backend_request_entropy(RngBackend *s, size_t size,
  19                                  EntropyReceiveFunc *receive_entropy,
  20                                  void *opaque)
  21 {
  22     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  23
  24     if (k->request_entropy) {
  25         k->request_entropy(s, size, receive_entropy, opaque);
  26     }
  27 }
  28
  29 void rng_backend_cancel_requests(RngBackend *s)
  30 {
  31     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  32
  33     if (k->cancel_requests) {
  34         k->cancel_requests(s);
  35     }
  36 }
  37
  38 static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  39 {
  40     RngBackend *s = RNG_BACKEND(obj);
  41
  42     return s->opened;
  43 }
  44
  45 static void rng_backend_complete(UserCreatable *uc, Error **errp)
  46 {
  47     object_property_set_bool(OBJECT(uc), true, "opened", errp);
  48 }
  49
  50 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
  51 {
  52     RngBackend *s = RNG_BACKEND(obj);
  53     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  54     Error *local_err = NULL;
  55
  56     if (value == s->opened) {
  57         return;
  58     }
  59
  60     if (!value && s->opened) {
  61         error_setg(errp, QERR_PERMISSION_DENIED);
  62         return;
  63     }
  64
  65     if (k->opened) {
  66         k->opened(s, &local_err);
  67         if (local_err) {
  68             error_propagate(errp, local_err);
  69             return;
  70         }
  71     }
  72
  73     s->opened = true;
  74 }
  75
  76 static void rng_backend_init(Object *obj)
  77 {
  78     object_property_add_bool(obj, "opened",
  79                              rng_backend_prop_get_opened,
  80                              rng_backend_prop_set_opened,
  81                              NULL);
  82 }
  83
  84 static void rng_backend_class_init(ObjectClass *oc, void *data)
  85 {
  86     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
  87
  88     ucc->complete = rng_backend_complete;
  89 }
  90
  91 static const TypeInfo rng_backend_info = {
  92     .name = TYPE_RNG_BACKEND,
  93     .parent = TYPE_OBJECT,
  94     .instance_size = sizeof(RngBackend),
  95     .instance_init = rng_backend_init,
  96     .class_size = sizeof(RngBackendClass),
  97     .class_init = rng_backend_class_init,
  98     .abstract = true,
  99     .interfaces = (InterfaceInfo[]) {
 100         { TYPE_USER_CREATABLE },
 101         { }
 102     }
 103 };
 104
 105 static void register_types(void)
 106 {
 107     type_register_static(&rng_backend_info);
 108 }
 109
 110 type_init(register_types);