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 "qom/object_interfaces.h" 18 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 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 48 static void rng_backend_complete(UserCreatable *uc, Error **errp) 49 { 50 object_property_set_bool(OBJECT(uc), true, "opened", errp); 51 } 52 53 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp) 54 { 55 RngBackend *s = RNG_BACKEND(obj); 56 RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); 57 Error *local_err = NULL; 58 59 if (value == s->opened) { 60 return; 61 } 62 63 if (!value && s->opened) { 64 error_setg(errp, QERR_PERMISSION_DENIED); 65 return; 66 } 67 68 if (k->opened) { 69 k->opened(s, &local_err); 70 if (local_err) { 71 error_propagate(errp, local_err); 72 return; 73 } 74 } 75 76 s->opened = true; 77 } 78 79 static void rng_backend_free_request(RngRequest *req) 80 { 81 g_free(req->data); 82 g_free(req); 83 } 84 85 static void rng_backend_free_requests(RngBackend *s) 86 { 87 RngRequest *req, *next; 88 89 QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) { 90 rng_backend_free_request(req); 91 } 92 93 QSIMPLEQ_INIT(&s->requests); 94 } 95 96 void rng_backend_finalize_request(RngBackend *s, RngRequest *req) 97 { 98 QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next); 99 rng_backend_free_request(req); 100 } 101 102 static void rng_backend_init(Object *obj) 103 { 104 RngBackend *s = RNG_BACKEND(obj); 105 106 QSIMPLEQ_INIT(&s->requests); 107 108 object_property_add_bool(obj, "opened", 109 rng_backend_prop_get_opened, 110 rng_backend_prop_set_opened, 111 NULL); 112 } 113 114 static void rng_backend_finalize(Object *obj) 115 { 116 RngBackend *s = RNG_BACKEND(obj); 117 118 rng_backend_free_requests(s); 119 } 120 121 static void rng_backend_class_init(ObjectClass *oc, void *data) 122 { 123 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); 124 125 ucc->complete = rng_backend_complete; 126 } 127 128 static const TypeInfo rng_backend_info = { 129 .name = TYPE_RNG_BACKEND, 130 .parent = TYPE_OBJECT, 131 .instance_size = sizeof(RngBackend), 132 .instance_init = rng_backend_init, 133 .instance_finalize = rng_backend_finalize, 134 .class_size = sizeof(RngBackendClass), 135 .class_init = rng_backend_class_init, 136 .abstract = true, 137 .interfaces = (InterfaceInfo[]) { 138 { TYPE_USER_CREATABLE }, 139 { } 140 } 141 }; 142 143 static void register_types(void) 144 { 145 type_register_static(&rng_backend_info); 146 } 147 148 type_init(register_types); 149