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
20void 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
42static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
43{
44 RngBackend *s = RNG_BACKEND(obj);
45
46 return s->opened;
47}
48
49static void rng_backend_complete(UserCreatable *uc, Error **errp)
50{
51 object_property_set_bool(OBJECT(uc), true, "opened", errp);
52}
53
54static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
55{
56 RngBackend *s = RNG_BACKEND(obj);
57 RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
58 Error *local_err = NULL;
59
60 if (value == s->opened) {
61 return;
62 }
63
64 if (!value && s->opened) {
65 error_setg(errp, QERR_PERMISSION_DENIED);
66 return;
67 }
68
69 if (k->opened) {
70 k->opened(s, &local_err);
71 if (local_err) {
72 error_propagate(errp, local_err);
73 return;
74 }
75 }
76
77 s->opened = true;
78}
79
80static void rng_backend_free_request(RngRequest *req)
81{
82 g_free(req->data);
83 g_free(req);
84}
85
86static void rng_backend_free_requests(RngBackend *s)
87{
88 RngRequest *req, *next;
89
90 QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) {
91 rng_backend_free_request(req);
92 }
93
94 QSIMPLEQ_INIT(&s->requests);
95}
96
97void rng_backend_finalize_request(RngBackend *s, RngRequest *req)
98{
99 QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next);
100 rng_backend_free_request(req);
101}
102
103static void rng_backend_init(Object *obj)
104{
105 RngBackend *s = RNG_BACKEND(obj);
106
107 QSIMPLEQ_INIT(&s->requests);
108
109 object_property_add_bool(obj, "opened",
110 rng_backend_prop_get_opened,
111 rng_backend_prop_set_opened,
112 NULL);
113}
114
115static void rng_backend_finalize(Object *obj)
116{
117 RngBackend *s = RNG_BACKEND(obj);
118
119 rng_backend_free_requests(s);
120}
121
122static void rng_backend_class_init(ObjectClass *oc, void *data)
123{
124 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
125
126 ucc->complete = rng_backend_complete;
127}
128
129static const TypeInfo rng_backend_info = {
130 .name = TYPE_RNG_BACKEND,
131 .parent = TYPE_OBJECT,
132 .instance_size = sizeof(RngBackend),
133 .instance_init = rng_backend_init,
134 .instance_finalize = rng_backend_finalize,
135 .class_size = sizeof(RngBackendClass),
136 .class_init = rng_backend_class_init,
137 .abstract = true,
138 .interfaces = (InterfaceInfo[]) {
139 { TYPE_USER_CREATABLE },
140 { }
141 }
142};
143
144static void register_types(void)
145{
146 type_register_static(&rng_backend_info);
147}
148
149type_init(register_types);
150