xref: /openbmc/qemu/authz/listfile.c (revision e6546342)
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_init = qauthz_list_file_class_init,
267     .interfaces = (InterfaceInfo[]) {
268         { TYPE_USER_CREATABLE },
269         { }
270     }
271 };
272 
273 
274 static void
275 qauthz_list_file_register_types(void)
276 {
277     type_register_static(&qauthz_list_file_info);
278 }
279 
280 
281 type_init(qauthz_list_file_register_types);
282