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13#include "qemu/osdep.h"
14#include "sysemu/rng-random.h"
15#include "sysemu/rng.h"
16#include "qapi/error.h"
17#include "qapi/qmp/qerror.h"
18#include "qemu/main-loop.h"
19#include "qemu/module.h"
20
21struct RngRandom
22{
23 RngBackend parent;
24
25 int fd;
26 char *filename;
27};
28
29
30
31
32
33
34
35
36static void entropy_available(void *opaque)
37{
38 RngRandom *s = RNG_RANDOM(opaque);
39
40 while (!QSIMPLEQ_EMPTY(&s->parent.requests)) {
41 RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);
42 ssize_t len;
43
44 len = read(s->fd, req->data, req->size);
45 if (len < 0 && errno == EAGAIN) {
46 return;
47 }
48 g_assert(len != -1);
49
50 req->receive_entropy(req->opaque, req->data, len);
51
52 rng_backend_finalize_request(&s->parent, req);
53 }
54
55
56 qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
57}
58
59static void rng_random_request_entropy(RngBackend *b, RngRequest *req)
60{
61 RngRandom *s = RNG_RANDOM(b);
62
63 if (QSIMPLEQ_EMPTY(&s->parent.requests)) {
64
65
66 qemu_set_fd_handler(s->fd, entropy_available, NULL, s);
67 }
68}
69
70static void rng_random_opened(RngBackend *b, Error **errp)
71{
72 RngRandom *s = RNG_RANDOM(b);
73
74 if (s->filename == NULL) {
75 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
76 "filename", "a valid filename");
77 } else {
78 s->fd = qemu_open_old(s->filename, O_RDONLY | O_NONBLOCK);
79 if (s->fd == -1) {
80 error_setg_file_open(errp, errno, s->filename);
81 }
82 }
83}
84
85static char *rng_random_get_filename(Object *obj, Error **errp)
86{
87 RngRandom *s = RNG_RANDOM(obj);
88
89 return g_strdup(s->filename);
90}
91
92static void rng_random_set_filename(Object *obj, const char *filename,
93 Error **errp)
94{
95 RngBackend *b = RNG_BACKEND(obj);
96 RngRandom *s = RNG_RANDOM(obj);
97
98 if (b->opened) {
99 error_setg(errp, QERR_PERMISSION_DENIED);
100 return;
101 }
102
103 g_free(s->filename);
104 s->filename = g_strdup(filename);
105}
106
107static void rng_random_init(Object *obj)
108{
109 RngRandom *s = RNG_RANDOM(obj);
110
111 s->filename = g_strdup("/dev/urandom");
112 s->fd = -1;
113}
114
115static void rng_random_finalize(Object *obj)
116{
117 RngRandom *s = RNG_RANDOM(obj);
118
119 if (s->fd != -1) {
120 qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
121 qemu_close(s->fd);
122 }
123
124 g_free(s->filename);
125}
126
127static void rng_random_class_init(ObjectClass *klass, void *data)
128{
129 RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
130
131 rbc->request_entropy = rng_random_request_entropy;
132 rbc->opened = rng_random_opened;
133 object_class_property_add_str(klass, "filename",
134 rng_random_get_filename,
135 rng_random_set_filename);
136
137}
138
139static const TypeInfo rng_random_info = {
140 .name = TYPE_RNG_RANDOM,
141 .parent = TYPE_RNG_BACKEND,
142 .instance_size = sizeof(RngRandom),
143 .class_init = rng_random_class_init,
144 .instance_init = rng_random_init,
145 .instance_finalize = rng_random_finalize,
146};
147
148static void register_types(void)
149{
150 type_register_static(&rng_random_info);
151}
152
153type_init(register_types);
154