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 "qemu/module.h"
  17 #include "qom/object_interfaces.h"
  18
  19 void rng_backend_request_entropy(RngBackend *s, size_t size,
  20                                  EntropyReceiveFunc *receive_entropy,
  21                                  void *opaque)
  22 {
  23     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  24     RngRequest *req;
  25
  26     if (k->request_entropy) {
  27         req = g_malloc(sizeof(*req));
  28
  29         req->offset = 0;
  30         req->size = size;
  31         req->receive_entropy = receive_entropy;
  32         req->opaque = opaque;
  33         req->data = g_malloc(req->size);
  34
  35         k->request_entropy(s, req);
  36
  37         QSIMPLEQ_INSERT_TAIL(&s->requests, req, next);
  38     }
  39 }
  40
  41 static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
  42 {
  43     RngBackend *s = RNG_BACKEND(obj);
  44
  45     return s->opened;
  46 }
  47
  48 static void rng_backend_complete(UserCreatable *uc, Error **errp)
  49 {
  50     RngBackend *s = RNG_BACKEND(uc);
  51     RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
  52     Error *local_err = NULL;
  53
  54     if (k->opened) {
  55         k->opened(s, &local_err);
  56         if (local_err) {
  57             error_propagate(errp, local_err);
  58             return;
  59         }
  60     }
  61
  62     s->opened = true;
  63 }
  64
  65 static void rng_backend_free_request(RngRequest *req)
  66 {
  67     g_free(req->data);
  68     g_free(req);
  69 }
  70
  71 static void rng_backend_free_requests(RngBackend *s)
  72 {
  73     RngRequest *req, *next;
  74
  75     QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) {
  76         rng_backend_free_request(req);
  77     }
  78
  79     QSIMPLEQ_INIT(&s->requests);
  80 }
  81
  82 void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
  83 {
  84     QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next);
  85     rng_backend_free_request(req);
  86 }
  87
  88 static void rng_backend_init(Object *obj)
  89 {
  90     RngBackend *s = RNG_BACKEND(obj);
  91
  92     QSIMPLEQ_INIT(&s->requests);
  93 }
  94
  95 static void rng_backend_finalize(Object *obj)
  96 {
  97     RngBackend *s = RNG_BACKEND(obj);
  98
  99     rng_backend_free_requests(s);
 100 }
 101
 102 static void rng_backend_class_init(ObjectClass *oc, void *data)
 103 {
 104     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 105
 106     ucc->complete = rng_backend_complete;
 107
 108     object_class_property_add_bool(oc, "opened",
 109                                    rng_backend_prop_get_opened,
 110                                    NULL);
 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);