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/error.h"
  16 #include "qapi/qmp/qerror.h"
  17 #include "qemu/module.h"
  18 #include "qom/object_interfaces.h"
  19
  20 void rng_backend_request_entropy(RngBackend *s, size_t size,
  21                                  EntropyReceiveFunc *receive_entropy,
  22                                  void *opaque)
  23 {
  24     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  25     RngRequest *req;
  26
  27     if (k->request_entropy) {
  28         req = g_malloc(sizeof(*req));
  29
  30         req->offset = 0;
  31         req->size = size;
  32         req->receive_entropy = receive_entropy;
  33         req->opaque = opaque;
  34         req->data = g_malloc(req->size);
  35
  36         k->request_entropy(s, req);
  37
  38         QSIMPLEQ_INSERT_TAIL(&s->requests, req, next);
  39     }
  40 }
  41
  42 static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  43 {
  44     RngBackend *s = RNG_BACKEND(obj);
  45
  46     return s->opened;
  47 }
  48
  49 static void rng_backend_complete(UserCreatable *uc, Error **errp)
  50 {
  51     RngBackend *s = RNG_BACKEND(uc);
  52     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  53     Error *local_err = NULL;
  54
  55     if (k->opened) {
  56         k->opened(s, &local_err);
  57         if (local_err) {
  58             error_propagate(errp, local_err);
  59             return;
  60         }
  61     }
  62
  63     s->opened = true;
  64 }
  65
  66 static void rng_backend_free_request(RngRequest *req)
  67 {
  68     g_free(req->data);
  69     g_free(req);
  70 }
  71
  72 static void rng_backend_free_requests(RngBackend *s)
  73 {
  74     RngRequest *req, *next;
  75
  76     QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) {
  77         rng_backend_free_request(req);
  78     }
  79
  80     QSIMPLEQ_INIT(&s->requests);
  81 }
  82
  83 void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
  84 {
  85     QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next);
  86     rng_backend_free_request(req);
  87 }
  88
  89 static void rng_backend_init(Object *obj)
  90 {
  91     RngBackend *s = RNG_BACKEND(obj);
  92
  93     QSIMPLEQ_INIT(&s->requests);
  94 }
  95
  96 static void rng_backend_finalize(Object *obj)
  97 {
  98     RngBackend *s = RNG_BACKEND(obj);
  99
 100     rng_backend_free_requests(s);
 101 }
 102
 103 static void rng_backend_class_init(ObjectClass *oc, void *data)
 104 {
 105     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 106
 107     ucc->complete = rng_backend_complete;
 108
 109     object_class_property_add_bool(oc, "opened",
 110                                    rng_backend_prop_get_opened,
 111                                    NULL);
 112 }
 113
 114 static const TypeInfo rng_backend_info = {
 115     .name = TYPE_RNG_BACKEND,
 116     .parent = TYPE_OBJECT,
 117     .instance_size = sizeof(RngBackend),
 118     .instance_init = rng_backend_init,
 119     .instance_finalize = rng_backend_finalize,
 120     .class_size = sizeof(RngBackendClass),
 121     .class_init = rng_backend_class_init,
 122     .abstract = true,
 123     .interfaces = (InterfaceInfo[]) {
 124         { TYPE_USER_CREATABLE },
 125         { }
 126     }
 127 };
 128
 129 static void register_types(void)
 130 {
 131     type_register_static(&rng_backend_info);
 132 }
 133
 134 type_init(register_types);