xref: /openbmc/qemu/authz/listfile.c (revision b097ba37)
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 "authz/trace.h"
24 #include "qemu/error-report.h"
25 #include "qemu/main-loop.h"
26 #include "qemu/sockets.h"
27 #include "qemu/filemonitor.h"
28 #include "qom/object_interfaces.h"
29 #include "qapi/qapi-visit-authz.h"
30 #include "qapi/qmp/qjson.h"
31 #include "qapi/qmp/qobject.h"
32 #include "qapi/qmp/qerror.h"
33 #include "qapi/qobject-input-visitor.h"
34 
35 
36 static bool
37 qauthz_list_file_is_allowed(QAuthZ *authz,
38                             const char *identity,
39                             Error **errp)
40 {
41     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(authz);
42     if (fauthz->list) {
43         return qauthz_is_allowed(fauthz->list, identity, errp);
44     }
45 
46     return false;
47 }
48 
49 
50 static QAuthZ *
51 qauthz_list_file_load(QAuthZListFile *fauthz, Error **errp)
52 {
53     GError *err = NULL;
54     gchar *content = NULL;
55     gsize len;
56     QObject *obj = NULL;
57     QDict *pdict;
58     Visitor *v = NULL;
59     QAuthZ *ret = NULL;
60 
61     trace_qauthz_list_file_load(fauthz, fauthz->filename);
62     if (!g_file_get_contents(fauthz->filename, &content, &len, &err)) {
63         error_setg(errp, "Unable to read '%s': %s",
64                    fauthz->filename, err->message);
65         goto cleanup;
66     }
67 
68     obj = qobject_from_json(content, errp);
69     if (!obj) {
70         goto cleanup;
71     }
72 
73     pdict = qobject_to(QDict, obj);
74     if (!pdict) {
75         error_setg(errp, QERR_INVALID_PARAMETER_TYPE, "obj", "dict");
76         goto cleanup;
77     }
78 
79     v = qobject_input_visitor_new(obj);
80 
81     ret = (QAuthZ *)user_creatable_add_type(TYPE_QAUTHZ_LIST,
82                                             NULL, pdict, v, errp);
83 
84  cleanup:
85     visit_free(v);
86     qobject_unref(obj);
87     if (err) {
88         g_error_free(err);
89     }
90     g_free(content);
91     return ret;
92 }
93 
94 
95 static void
96 qauthz_list_file_event(int64_t wd G_GNUC_UNUSED,
97                        QFileMonitorEvent ev G_GNUC_UNUSED,
98                        const char *name G_GNUC_UNUSED,
99                        void *opaque)
100 {
101     QAuthZListFile *fauthz = opaque;
102     Error *err = NULL;
103 
104     if (ev != QFILE_MONITOR_EVENT_MODIFIED &&
105         ev != QFILE_MONITOR_EVENT_CREATED) {
106         return;
107     }
108 
109     object_unref(OBJECT(fauthz->list));
110     fauthz->list = qauthz_list_file_load(fauthz, &err);
111     trace_qauthz_list_file_refresh(fauthz,
112                                    fauthz->filename, fauthz->list ? 1 : 0);
113     if (!fauthz->list) {
114         error_report_err(err);
115     }
116 }
117 
118 static void
119 qauthz_list_file_complete(UserCreatable *uc, Error **errp)
120 {
121     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(uc);
122     gchar *dir = NULL, *file = NULL;
123 
124     fauthz->list = qauthz_list_file_load(fauthz, errp);
125 
126     if (!fauthz->refresh) {
127         return;
128     }
129 
130     fauthz->file_monitor = qemu_file_monitor_new(errp);
131     if (!fauthz->file_monitor) {
132         return;
133     }
134 
135     dir = g_path_get_dirname(fauthz->filename);
136     if (g_str_equal(dir, ".")) {
137         error_setg(errp, "Filename must be an absolute path");
138         goto cleanup;
139     }
140     file = g_path_get_basename(fauthz->filename);
141     if (g_str_equal(file, ".")) {
142         error_setg(errp, "Path has no trailing filename component");
143         goto cleanup;
144     }
145 
146     fauthz->file_watch = qemu_file_monitor_add_watch(
147         fauthz->file_monitor, dir, file,
148         qauthz_list_file_event, fauthz, errp);
149     if (fauthz->file_watch < 0) {
150         goto cleanup;
151     }
152 
153  cleanup:
154     g_free(file);
155     g_free(dir);
156 }
157 
158 
159 static void
160 qauthz_list_file_prop_set_filename(Object *obj,
161                                    const char *value,
162                                    Error **errp G_GNUC_UNUSED)
163 {
164     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
165 
166     g_free(fauthz->filename);
167     fauthz->filename = g_strdup(value);
168 }
169 
170 
171 static char *
172 qauthz_list_file_prop_get_filename(Object *obj,
173                                    Error **errp G_GNUC_UNUSED)
174 {
175     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
176 
177     return g_strdup(fauthz->filename);
178 }
179 
180 
181 static void
182 qauthz_list_file_prop_set_refresh(Object *obj,
183                                   bool value,
184                                   Error **errp G_GNUC_UNUSED)
185 {
186     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
187 
188     fauthz->refresh = value;
189 }
190 
191 
192 static bool
193 qauthz_list_file_prop_get_refresh(Object *obj,
194                                   Error **errp G_GNUC_UNUSED)
195 {
196     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
197 
198     return fauthz->refresh;
199 }
200 
201 
202 static void
203 qauthz_list_file_finalize(Object *obj)
204 {
205     QAuthZListFile *fauthz = QAUTHZ_LIST_FILE(obj);
206 
207     object_unref(OBJECT(fauthz->list));
208     g_free(fauthz->filename);
209     qemu_file_monitor_free(fauthz->file_monitor);
210 }
211 
212 
213 static void
214 qauthz_list_file_class_init(ObjectClass *oc, void *data)
215 {
216     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
217     QAuthZClass *authz = QAUTHZ_CLASS(oc);
218 
219     ucc->complete = qauthz_list_file_complete;
220 
221     object_class_property_add_str(oc, "filename",
222                                   qauthz_list_file_prop_get_filename,
223                                   qauthz_list_file_prop_set_filename,
224                                   NULL);
225     object_class_property_add_bool(oc, "refresh",
226                                    qauthz_list_file_prop_get_refresh,
227                                    qauthz_list_file_prop_set_refresh,
228                                    NULL);
229 
230     authz->is_allowed = qauthz_list_file_is_allowed;
231 }
232 
233 
234 static void
235 qauthz_list_file_init(Object *obj)
236 {
237     QAuthZListFile *authz = QAUTHZ_LIST_FILE(obj);
238 
239     authz->file_watch = -1;
240 #ifdef CONFIG_INOTIFY1
241     authz->refresh = TRUE;
242 #endif
243 }
244 
245 
246 QAuthZListFile *qauthz_list_file_new(const char *id,
247                                      const char *filename,
248                                      bool refresh,
249                                      Error **errp)
250 {
251     return QAUTHZ_LIST_FILE(
252         object_new_with_props(TYPE_QAUTHZ_LIST_FILE,
253                               object_get_objects_root(),
254                               id, errp,
255                               "filename", filename,
256                               "refresh", refresh ? "yes" : "no",
257                               NULL));
258 }
259 
260 
261 static const TypeInfo qauthz_list_file_info = {
262     .parent = TYPE_QAUTHZ,
263     .name = TYPE_QAUTHZ_LIST_FILE,
264     .instance_init = qauthz_list_file_init,
265     .instance_size = sizeof(QAuthZListFile),
266     .instance_finalize = qauthz_list_file_finalize,
267     .class_size = sizeof(QAuthZListFileClass),
268     .class_init = qauthz_list_file_class_init,
269     .interfaces = (InterfaceInfo[]) {
270         { TYPE_USER_CREATABLE },
271         { }
272     }
273 };
274 
275 
276 static void
277 qauthz_list_file_register_types(void)
278 {
279     type_register_static(&qauthz_list_file_info);
280 }
281 
282 
283 type_init(qauthz_list_file_register_types);
284