xref: /openbmc/qemu/backends/rng.c (revision c4b8ffcb)
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);
135