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     fauthz->list = qauthz_list_file_load(fauthz, errp);
 126
 127     if (!fauthz->refresh) {
 128         return;
 129     }
 130
 131     fauthz->file_monitor = qemu_file_monitor_new(errp);
 132     if (!fauthz->file_monitor) {
 133         return;
 134     }
 135
 136     dir = g_path_get_dirname(fauthz->filename);
 137     if (g_str_equal(dir, ".")) {
 138         error_setg(errp, "Filename must be an absolute path");
 139         goto cleanup;
 140     }
 141     file = g_path_get_basename(fauthz->filename);
 142     if (g_str_equal(file, ".")) {
 143         error_setg(errp, "Path has no trailing filename component");
 144         goto cleanup;
 145     }
 146
 147     fauthz->file_watch = qemu_file_monitor_add_watch(
 148         fauthz->file_monitor, dir, file,
 149         qauthz_list_file_event, fauthz, errp);
 150     if (fauthz->file_watch < 0) {
 151         goto cleanup;
 152     }
 153
 154  cleanup:
 155     g_free(file);
 156     g_free(dir);
 157 }
 158
 159
 160 static void
 161 qauthz_list_file_prop_set_filename(Object *obj,
 162                                    const char *value,
 163                                    Error **errp G_GNUC_UNUSED)
 164 {
 165     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 166
 167     g_free(fauthz->filename);
 168     fauthz->filename = g_strdup(value);
 169 }
 170
 171
 172 static char *
 173 qauthz_list_file_prop_get_filename(Object *obj,
 174                                    Error **errp G_GNUC_UNUSED)
 175 {
 176     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 177
 178     return g_strdup(fauthz->filename);
 179 }
 180
 181
 182 static void
 183 qauthz_list_file_prop_set_refresh(Object *obj,
 184                                   bool value,
 185                                   Error **errp G_GNUC_UNUSED)
 186 {
 187     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 188
 189     fauthz->refresh = value;
 190 }
 191
 192
 193 static bool
 194 qauthz_list_file_prop_get_refresh(Object *obj,
 195                                   Error **errp G_GNUC_UNUSED)
 196 {
 197     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 198
 199     return fauthz->refresh;
 200 }
 201
 202
 203 static void
 204 qauthz_list_file_finalize(Object *obj)
 205 {
 206     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
 207
 208     object_unref(OBJECT(fauthz->list));
 209     g_free(fauthz->filename);
 210     qemu_file_monitor_free(fauthz->file_monitor);
 211 }
 212
 213
 214 static void
 215 qauthz_list_file_class_init(ObjectClass *oc, void *data)
 216 {
 217     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 218     QAuthZClass *authz = QAUTHZ_CLASS(oc);
 219
 220     ucc->complete = qauthz_list_file_complete;
 221
 222     object_class_property_add_str(oc, "filename",
 223                                   qauthz_list_file_prop_get_filename,
 224                                   qauthz_list_file_prop_set_filename);
 225     object_class_property_add_bool(oc, "refresh",
 226                                    qauthz_list_file_prop_get_refresh,
 227                                    qauthz_list_file_prop_set_refresh);
 228
 229     authz->is_allowed = qauthz_list_file_is_allowed;
 230 }
 231
 232
 233 static void
 234 qauthz_list_file_init(Object *obj)
 235 {
 236     QAuthZListFile *authz = QAUTHZ_LIST_FILE(obj);
 237
 238     authz->file_watch = -1;
 239 #ifdef CONFIG_INOTIFY1
 240     authz->refresh = true;
 241 #endif
 242 }
 243
 244
 245 QAuthZListFile *qauthz_list_file_new(const char *id,
 246                                      const char *filename,
 247                                      bool refresh,
 248                                      Error **errp)
 249 {
 250     return QAUTHZ_LIST_FILE(
 251         object_new_with_props(TYPE_QAUTHZ_LIST_FILE,
 252                               object_get_objects_root(),
 253                               id, errp,
 254                               "filename", filename,
 255                               "refresh", refresh ? "yes" : "no",
 256                               NULL));
 257 }
 258
 259
 260 static const TypeInfo qauthz_list_file_info = {
 261     .parent = TYPE_QAUTHZ,
 262     .name = TYPE_QAUTHZ_LIST_FILE,
 263     .instance_init = qauthz_list_file_init,
 264     .instance_size = sizeof(QAuthZListFile),
 265     .instance_finalize = qauthz_list_file_finalize,
 266     .class_size = sizeof(QAuthZListFileClass),
 267     .class_init = qauthz_list_file_class_init,
 268     .interfaces = (InterfaceInfo[]) {
 269         { TYPE_USER_CREATABLE },
 270         { }
 271     }
 272 };
 273
 274
 275 static void
 276 qauthz_list_file_register_types(void)
 277 {
 278     type_register_static(&qauthz_list_file_info);
 279 }
 280
 281
 282 type_init(qauthz_list_file_register_types);