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 static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  30 {
  31     RngBackend *s = RNG_BACKEND(obj);
  32
  33     return s->opened;
  34 }
  35
  36 static void rng_backend_complete(UserCreatable *uc, Error **errp)
  37 {
  38     object_property_set_bool(OBJECT(uc), true, "opened", errp);
  39 }
  40
  41 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
  42 {
  43     RngBackend *s = RNG_BACKEND(obj);
  44     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  45     Error *local_err = NULL;
  46
  47     if (value == s->opened) {
  48         return;
  49     }
  50
  51     if (!value && s->opened) {
  52         error_setg(errp, QERR_PERMISSION_DENIED);
  53         return;
  54     }
  55
  56     if (k->opened) {
  57         k->opened(s, &local_err);
  58         if (local_err) {
  59             error_propagate(errp, local_err);
  60             return;
  61         }
  62     }
  63
  64     s->opened = true;
  65 }
  66
  67 static void rng_backend_free_request(RngRequest *req)
  68 {
  69     g_free(req->data);
  70     g_free(req);
  71 }
  72
  73 static void rng_backend_free_requests(RngBackend *s)
  74 {
  75     GSList *i;
  76
  77     for (i = s->requests; i; i = i->next) {
  78         rng_backend_free_request(i->data);
  79     }
  80
  81     g_slist_free(s->requests);
  82     s->requests = NULL;
  83 }
  84
  85 void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
  86 {
  87     s->requests = g_slist_remove(s->requests, req);
  88     rng_backend_free_request(req);
  89 }
  90
  91 static void rng_backend_init(Object *obj)
  92 {
  93     object_property_add_bool(obj, "opened",
  94                              rng_backend_prop_get_opened,
  95                              rng_backend_prop_set_opened,
  96                              NULL);
  97 }
  98
  99 static void rng_backend_finalize(Object *obj)
 100 {
 101     RngBackend *s = RNG_BACKEND(obj);
 102
 103     rng_backend_free_requests(s);
 104 }
 105
 106 static void rng_backend_class_init(ObjectClass *oc, void *data)
 107 {
 108     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 109
 110     ucc->complete = rng_backend_complete;
 111 }
 112
 113 static const TypeInfo rng_backend_info = {
 114     .name = TYPE_RNG_BACKEND,
 115     .parent = TYPE_OBJECT,
 116     .instance_size = sizeof(RngBackend),
 117     .instance_init = rng_backend_init,
 118     .instance_finalize = rng_backend_finalize,
 119     .class_size = sizeof(RngBackendClass),
 120     .class_init = rng_backend_class_init,
 121     .abstract = true,
 122     .interfaces = (InterfaceInfo[]) {
 123         { TYPE_USER_CREATABLE },
 124         { }
 125     }
 126 };
 127
 128 static void register_types(void)
 129 {
 130     type_register_static(&rng_backend_info);
 131 }
 132
 133 type_init(register_types);