authz/listfile.c

   1 /*
   2  * QEMU access control list file authorization driver
   3  *
   4  * Copyright (c) 2018 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "authz/listfile.h"
  23 #include "trace.h"
  24 #include "qemu/error-report.h"
  25 #include "qemu/main-loop.h"
  26 #include "qemu/module.h"
  27 #include "qemu/sockets.h"
  28 #include "qemu/filemonitor.h"
  29 #include "qom/object_interfaces.h"
  30 #include "qapi/qapi-visit-authz.h"
  31 #include "qapi/qmp/qjson.h"
  32 #include "qapi/qmp/qobject.h"
  33 #include "qapi/qmp/qerror.h"
  34 #include "qapi/qobject-input-visitor.h"
  35
  36
  37 static bool
  38 qauthz_list_file_is_allowed(QAuthZ *authz,
  39                             const char *identity,
  40                             Error **errp)
  41 {
  42     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(authz);
  43     if (fauthz->list) {
  44         return qauthz_is_allowed(fauthz->list, identity, errp);
  45     }
  46
  47     return false;
  48 }
  49
  50
  51 static QAuthZ *
  52 qauthz_list_file_load(QAuthZListFile *fauthz, Error **errp)
  53 {
  54     GError *err = NULL;
  55     gchar *content = NULL;
  56     gsize len;
  57     QObject *obj = NULL;
  58     QDict *pdict;
  59     Visitor *v = NULL;
  60     QAuthZ *ret = NULL;
  61
  62     trace_qauthz_list_file_load(fauthz, fauthz->filename);
  63     if (!g_file_get_contents(fauthz->filename, &content, &len, &err)) {
  64         error_setg(errp, "Unable to read '%s': %s",
  65                    fauthz->filename, err->message);
  66         goto cleanup;
  67     }
  68
  69     obj = qobject_from_json(content, errp);
  70     if (!obj) {
  71         goto cleanup;
  72     }
  73
  74     pdict = qobject_to(QDict, obj);
  75     if (!pdict) {
  76         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, "obj", "dict");
  77         goto cleanup;
  78     }
  79
  80     v = qobject_input_visitor_new(obj);
  81
  82     ret = (QAuthZ *)user_creatable_add_type(TYPE_QAUTHZ_LIST,
  83                                             NULL, pdict, v, errp);
  84
  85  cleanup:
  86     visit_free(v);
  87     qobject_unref(obj);
  88     if (err) {
  89         g_error_free(err);
  90     }
  91     g_free(content);
  92     return ret;
  93 }
  94
  95
  96 static void
  97 qauthz_list_file_event(int64_t wd G_GNUC_UNUSED,
  98                        QFileMonitorEvent ev G_GNUC_UNUSED,
  99                        const char *name G_GNUC_UNUSED,
 100                        void *opaque)
 101 {
 102     QAuthZListFile *fauthz = opaque;
 103     Error *err = NULL;
 104
 105     if (ev != QFILE_MONITOR_EVENT_MODIFIED &&
 106         ev != QFILE_MONITOR_EVENT_CREATED) {
 107         return;
 108     }
 109
 110     object_unref(OBJECT(fauthz->list));
 111     fauthz->list = qauthz_list_file_load(fauthz, &err);
 112     trace_qauthz_list_file_refresh(fauthz,
 113                                    fauthz->filename, fauthz->list ? 1 : 0);
 114     if (!fauthz->list) {
 115         error_report_err(err);
 116     }
 117 }
 118
 119 static void
 120 qauthz_list_file_complete(UserCreatable *uc, Error **errp)
 121 {
 122     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(uc);
 123     gchar *dir = NULL, *file = NULL;
 124
 125     if (!fauthz->filename) {
 126         error_setg(errp, "filename not provided");
 127         return;
 128     }
 129
 130     fauthz->list = qauthz_list_file_load(fauthz, errp);
 131
 132     if (!fauthz->refresh) {
 133         return;
 134     }
 135
 136     fauthz->file_monitor = qemu_file_monitor_new(errp);
 137     if (!fauthz->file_monitor) {
 138         return;
 139     }
 140
 141     dir = g_path_get_dirname(fauthz->filename);
 142     if (g_str_equal(dir, ".")) {
 143         error_setg(errp, "Filename must be an absolute path");
 144         goto cleanup;
 145     }
 146     file = g_path_get_basename(fauthz->filename);
 147     if (g_str_equal(file, ".")) {
 148         error_setg(errp, "Path has no trailing filename component");
 149         goto cleanup;
 150     }
 151
 152     fauthz->file_watch = qemu_file_monitor_add_watch(
 153         fauthz->file_monitor, dir, file,
 154         qauthz_list_file_event, fauthz, errp);
 155     if (fauthz->file_watch < 0) {
 156         goto cleanup;
 157     }
 158
 159  cleanup:
 160     g_free(file);
 161     g_free(dir);
 162 }
 163
 164
 165 static void
 166 qauthz_list_file_prop_set_filename(Object *obj,
 167                                    const char *value,
 168                                    Error **errp G_GNUC_UNUSED)
 169 {
 170     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 171
 172     g_free(fauthz->filename);
 173     fauthz->filename = g_strdup(value);
 174 }
 175
 176
 177 static char *
 178 qauthz_list_file_prop_get_filename(Object *obj,
 179                                    Error **errp G_GNUC_UNUSED)
 180 {
 181     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 182
 183     return g_strdup(fauthz->filename);
 184 }
 185
 186
 187 static void
 188 qauthz_list_file_prop_set_refresh(Object *obj,
 189                                   bool value,
 190                                   Error **errp G_GNUC_UNUSED)
 191 {
 192     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 193
 194     fauthz->refresh = value;
 195 }
 196
 197
 198 static bool
 199 qauthz_list_file_prop_get_refresh(Object *obj,
 200                                   Error **errp G_GNUC_UNUSED)
 201 {
 202     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 203
 204     return fauthz->refresh;
 205 }
 206
 207
 208 static void
 209 qauthz_list_file_finalize(Object *obj)
 210 {
 211     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 212
 213     object_unref(OBJECT(fauthz->list));
 214     g_free(fauthz->filename);
 215     qemu_file_monitor_free(fauthz->file_monitor);
 216 }
 217
 218
 219 static void
 220 qauthz_list_file_class_init(ObjectClass *oc, void *data)
 221 {
 222     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 223     QAuthZClass *authz = QAUTHZ_CLASS(oc);
 224
 225     ucc->complete = qauthz_list_file_complete;
 226
 227     object_class_property_add_str(oc, "filename",
 228                                   qauthz_list_file_prop_get_filename,
 229                                   qauthz_list_file_prop_set_filename);
 230     object_class_property_add_bool(oc, "refresh",
 231                                    qauthz_list_file_prop_get_refresh,
 232                                    qauthz_list_file_prop_set_refresh);
 233
 234     authz->is_allowed = qauthz_list_file_is_allowed;
 235 }
 236
 237
 238 static void
 239 qauthz_list_file_init(Object *obj)
 240 {
 241     QAuthZListFile *authz = QAUTHZ_LIST_FILE(obj);
 242
 243     authz->file_watch = -1;
 244 #ifdef CONFIG_INOTIFY1
 245     authz->refresh = true;
 246 #endif
 247 }
 248
 249
 250 QAuthZListFile *qauthz_list_file_new(const char *id,
 251                                      const char *filename,
 252                                      bool refresh,
 253                                      Error **errp)
 254 {
 255     return QAUTHZ_LIST_FILE(
 256         object_new_with_props(TYPE_QAUTHZ_LIST_FILE,
 257                               object_get_objects_root(),
 258                               id, errp,
 259                               "filename", filename,
 260                               "refresh", refresh ? "yes" : "no",
 261                               NULL));
 262 }
 263
 264
 265 static const TypeInfo qauthz_list_file_info = {
 266     .parent = TYPE_QAUTHZ,
 267     .name = TYPE_QAUTHZ_LIST_FILE,
 268     .instance_init = qauthz_list_file_init,
 269     .instance_size = sizeof(QAuthZListFile),
 270     .instance_finalize = qauthz_list_file_finalize,
 271     .class_init = qauthz_list_file_class_init,
 272     .interfaces = (InterfaceInfo[]) {
 273         { TYPE_USER_CREATABLE },
 274         { }
 275     }
 276 };
 277
 278
 279 static void
 280 qauthz_list_file_register_types(void)
 281 {
 282     type_register_static(&qauthz_list_file_info);
 283 }
 284
 285
 286 type_init(qauthz_list_file_register_types);