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 object_property_set_bool(OBJECT(uc), true, "opened", errp); 52 } 53 54 static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp) 55 { 56 RngBackend *s = RNG_BACKEND(obj); 57 RngBackendClass *k = RNG_BACKEND_GET_CLASS(s); 58 Error *local_err = NULL; 59 60 if (value == s->opened) { 61 return; 62 } 63 64 if (!value && s->opened) { 65 error_setg(errp, QERR_PERMISSION_DENIED); 66 return; 67 } 68 69 if (k->opened) { 70 k->opened(s, &local_err); 71 if (local_err) { 72 error_propagate(errp, local_err); 73 return; 74 } 75 } 76 77 s->opened = true; 78 } 79 80 static void rng_backend_free_request(RngRequest *req) 81 { 82 g_free(req->data); 83 g_free(req); 84 } 85 86 static void rng_backend_free_requests(RngBackend *s) 87 { 88 RngRequest *req, *next; 89 90 QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) { 91 rng_backend_free_request(req); 92 } 93 94 QSIMPLEQ_INIT(&s->requests); 95 } 96 97 void rng_backend_finalize_request(RngBackend *s, RngRequest *req) 98 { 99 QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next); 100 rng_backend_free_request(req); 101 } 102 103 static void rng_backend_init(Object *obj) 104 { 105 RngBackend *s = RNG_BACKEND(obj); 106 107 QSIMPLEQ_INIT(&s->requests); 108 109 object_property_add_bool(obj, "opened", 110 rng_backend_prop_get_opened, 111 rng_backend_prop_set_opened); 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