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 s->requests = g_slist_append(s->requests, req); 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 GSList *i; 87 88 for (i = s->requests; i; i = i->next) { 89 rng_backend_free_request(i->data); 90 } 91 92 g_slist_free(s->requests); 93 s->requests = NULL; 94 } 95 96 void rng_backend_finalize_request(RngBackend *s, RngRequest *req) 97 { 98 s->requests = g_slist_remove(s->requests, req); 99 rng_backend_free_request(req); 100 } 101 102 static void rng_backend_init(Object *obj) 103 { 104 object_property_add_bool(obj, "opened", 105 rng_backend_prop_get_opened, 106 rng_backend_prop_set_opened, 107 NULL); 108 } 109 110 static void rng_backend_finalize(Object *obj) 111 { 112 RngBackend *s = RNG_BACKEND(obj); 113 114 rng_backend_free_requests(s); 115 } 116 117 static void rng_backend_class_init(ObjectClass *oc, void *data) 118 { 119 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); 120 121 ucc->complete = rng_backend_complete; 122 } 123 124 static const TypeInfo rng_backend_info = { 125 .name = TYPE_RNG_BACKEND, 126 .parent = TYPE_OBJECT, 127 .instance_size = sizeof(RngBackend), 128 .instance_init = rng_backend_init, 129 .instance_finalize = rng_backend_finalize, 130 .class_size = sizeof(RngBackendClass), 131 .class_init = rng_backend_class_init, 132 .abstract = true, 133 .interfaces = (InterfaceInfo[]) { 134 { TYPE_USER_CREATABLE }, 135 { } 136 } 137 }; 138 139 static void register_types(void) 140 { 141 type_register_static(&rng_backend_info); 142 } 143 144 type_init(register_types); 145