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/qmp/qerror.h" 16 #include "qom/object_interfaces.h" 17 18 void rng_backend_request_entropy(RngBackend *s, size_t size, 19 EntropyReceiveFunc *receive_entropy, 20 void *opaque) 21 { 22 RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); 23 RngRequest *req; 24 25 if (k->request_entropy) { 26 req = g_malloc(sizeof(*req)); 27 28 req->offset = 0; 29 req->size = size; 30 req->receive_entropy = receive_entropy; 31 req->opaque = opaque; 32 req->data = g_malloc(req->size); 33 34 k->request_entropy(s, req); 35 36 QSIMPLEQ_INSERT_TAIL(&s->requests, req, next); 37 } 38 } 39 40 static bool rng_backend_prop_get_opened(Object *obj, Error **errp) 41 { 42 RngBackend *s = RNG_BACKEND(obj); 43 44 return s->opened; 45 } 46 47 static void rng_backend_complete(UserCreatable *uc, Error **errp) 48 { 49 object_property_set_bool(OBJECT(uc), true, "opened", errp); 50 } 51 52 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp) 53 { 54 RngBackend *s = RNG_BACKEND(obj); 55 RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); 56 Error *local_err = NULL; 57 58 if (value == s->opened) { 59 return; 60 } 61 62 if (!value && s->opened) { 63 error_setg(errp, QERR_PERMISSION_DENIED); 64 return; 65 } 66 67 if (k->opened) { 68 k->opened(s, &local_err); 69 if (local_err) { 70 error_propagate(errp, local_err); 71 return; 72 } 73 } 74 75 s->opened = true; 76 } 77 78 static void rng_backend_free_request(RngRequest *req) 79 { 80 g_free(req->data); 81 g_free(req); 82 } 83 84 static void rng_backend_free_requests(RngBackend *s) 85 { 86 RngRequest *req, *next; 87 88 QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) { 89 rng_backend_free_request(req); 90 } 91 92 QSIMPLEQ_INIT(&s->requests); 93 } 94 95 void rng_backend_finalize_request(RngBackend *s, RngRequest *req) 96 { 97 QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next); 98 rng_backend_free_request(req); 99 } 100 101 static void rng_backend_init(Object *obj) 102 { 103 RngBackend *s = RNG_BACKEND(obj); 104 105 QSIMPLEQ_INIT(&s->requests); 106 107 object_property_add_bool(obj, "opened", 108 rng_backend_prop_get_opened, 109 rng_backend_prop_set_opened, 110 NULL); 111 } 112 113 static void rng_backend_finalize(Object *obj) 114 { 115 RngBackend *s = RNG_BACKEND(obj); 116 117 rng_backend_free_requests(s); 118 } 119 120 static void rng_backend_class_init(ObjectClass *oc, void *data) 121 { 122 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); 123 124 ucc->complete = rng_backend_complete; 125 } 126 127 static const TypeInfo rng_backend_info = { 128 .name = TYPE_RNG_BACKEND, 129 .parent = TYPE_OBJECT, 130 .instance_size = sizeof(RngBackend), 131 .instance_init = rng_backend_init, 132 .instance_finalize = rng_backend_finalize, 133 .class_size = sizeof(RngBackendClass), 134 .class_init = rng_backend_class_init, 135 .abstract = true, 136 .interfaces = (InterfaceInfo[]) { 137 { TYPE_USER_CREATABLE }, 138 { } 139 } 140 }; 141 142 static void register_types(void) 143 { 144 type_register_static(&rng_backend_info); 145 } 146 147 type_init(register_types); 148