xref: /openbmc/qemu/backends/rng.c (revision 6f1e91f7)
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 
rng_backend_request_entropy(RngBackend * s,size_t size,EntropyReceiveFunc * receive_entropy,void * opaque)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 
rng_backend_prop_get_opened(Object * obj,Error ** errp)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 
rng_backend_complete(UserCreatable * uc,Error ** errp)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 
rng_backend_free_request(RngRequest * req)65 static void rng_backend_free_request(RngRequest *req)
66 {
67     g_free(req->data);
68     g_free(req);
69 }
70 
rng_backend_free_requests(RngBackend * s)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 
rng_backend_finalize_request(RngBackend * s,RngRequest * req)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 
rng_backend_init(Object * obj)88 static void rng_backend_init(Object *obj)
89 {
90     RngBackend *s = RNG_BACKEND(obj);
91 
92     QSIMPLEQ_INIT(&s->requests);
93 }
94 
rng_backend_finalize(Object * obj)95 static void rng_backend_finalize(Object *obj)
96 {
97     RngBackend *s = RNG_BACKEND(obj);
98 
99     rng_backend_free_requests(s);
100 }
101 
rng_backend_class_init(ObjectClass * oc,void * data)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 
register_types(void)128 static void register_types(void)
129 {
130     type_register_static(&rng_backend_info);
131 }
132 
133 type_init(register_types);
134