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