xref: /openbmc/qemu/io/channel-tls.c (revision d1fd31f8) 
1 /*
2  * QEMU I/O channels TLS driver
3  *
4  * Copyright (c) 2015 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 "qapi/error.h"
23 #include "io/channel-tls.h"
24 #include "trace.h"
25 
26 
27 static ssize_t qio_channel_tls_write_handler(const char *buf,
28                                              size_t len,
29                                              void *opaque)
30 {
31     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
32     ssize_t ret;
33 
34     ret = qio_channel_write(tioc->master, buf, len, NULL);
35     if (ret == QIO_CHANNEL_ERR_BLOCK) {
36         errno = EAGAIN;
37         return -1;
38     } else if (ret < 0) {
39         errno = EIO;
40         return -1;
41     }
42     return ret;
43 }
44 
45 static ssize_t qio_channel_tls_read_handler(char *buf,
46                                             size_t len,
47                                             void *opaque)
48 {
49     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
50     ssize_t ret;
51 
52     ret = qio_channel_read(tioc->master, buf, len, NULL);
53     if (ret == QIO_CHANNEL_ERR_BLOCK) {
54         errno = EAGAIN;
55         return -1;
56     } else if (ret < 0) {
57         errno = EIO;
58         return -1;
59     }
60     return ret;
61 }
62 
63 
64 QIOChannelTLS *
65 qio_channel_tls_new_server(QIOChannel *master,
66                            QCryptoTLSCreds *creds,
67                            const char *aclname,
68                            Error **errp)
69 {
70     QIOChannelTLS *ioc;
71 
72     ioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
73 
74     ioc->master = master;
75     object_ref(OBJECT(master));
76 
77     ioc->session = qcrypto_tls_session_new(
78         creds,
79         NULL,
80         aclname,
81         QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
82         errp);
83     if (!ioc->session) {
84         goto error;
85     }
86 
87     qcrypto_tls_session_set_callbacks(
88         ioc->session,
89         qio_channel_tls_write_handler,
90         qio_channel_tls_read_handler,
91         ioc);
92 
93     trace_qio_channel_tls_new_server(ioc, master, creds, aclname);
94     return ioc;
95 
96  error:
97     object_unref(OBJECT(ioc));
98     return NULL;
99 }
100 
101 QIOChannelTLS *
102 qio_channel_tls_new_client(QIOChannel *master,
103                            QCryptoTLSCreds *creds,
104                            const char *hostname,
105                            Error **errp)
106 {
107     QIOChannelTLS *tioc;
108     QIOChannel *ioc;
109 
110     tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
111     ioc = QIO_CHANNEL(tioc);
112 
113     tioc->master = master;
114     if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
115         qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
116     }
117     object_ref(OBJECT(master));
118 
119     tioc->session = qcrypto_tls_session_new(
120         creds,
121         hostname,
122         NULL,
123         QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
124         errp);
125     if (!tioc->session) {
126         goto error;
127     }
128 
129     qcrypto_tls_session_set_callbacks(
130         tioc->session,
131         qio_channel_tls_write_handler,
132         qio_channel_tls_read_handler,
133         tioc);
134 
135     trace_qio_channel_tls_new_client(tioc, master, creds, hostname);
136     return tioc;
137 
138  error:
139     object_unref(OBJECT(tioc));
140     return NULL;
141 }
142 
143 struct QIOChannelTLSData {
144     QIOTask *task;
145     GMainContext *context;
146 };
147 typedef struct QIOChannelTLSData QIOChannelTLSData;
148 
149 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
150                                              GIOCondition condition,
151                                              gpointer user_data);
152 
153 static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
154                                            QIOTask *task,
155                                            GMainContext *context)
156 {
157     Error *err = NULL;
158     QCryptoTLSSessionHandshakeStatus status;
159 
160     if (qcrypto_tls_session_handshake(ioc->session, &err) < 0) {
161         trace_qio_channel_tls_handshake_fail(ioc);
162         qio_task_set_error(task, err);
163         qio_task_complete(task);
164         return;
165     }
166 
167     status = qcrypto_tls_session_get_handshake_status(ioc->session);
168     if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
169         trace_qio_channel_tls_handshake_complete(ioc);
170         if (qcrypto_tls_session_check_credentials(ioc->session,
171                                                   &err) < 0) {
172             trace_qio_channel_tls_credentials_deny(ioc);
173             qio_task_set_error(task, err);
174         } else {
175             trace_qio_channel_tls_credentials_allow(ioc);
176         }
177         qio_task_complete(task);
178     } else {
179         GIOCondition condition;
180         QIOChannelTLSData *data = g_new0(typeof(*data), 1);
181 
182         data->task = task;
183         data->context = context;
184 
185         if (context) {
186             g_main_context_ref(context);
187         }
188 
189         if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
190             condition = G_IO_OUT;
191         } else {
192             condition = G_IO_IN;
193         }
194 
195         trace_qio_channel_tls_handshake_pending(ioc, status);
196         qio_channel_add_watch_full(ioc->master,
197                                    condition,
198                                    qio_channel_tls_handshake_io,
199                                    data,
200                                    NULL,
201                                    context);
202     }
203 }
204 
205 
206 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
207                                              GIOCondition condition,
208                                              gpointer user_data)
209 {
210     QIOChannelTLSData *data = user_data;
211     QIOTask *task = data->task;
212     GMainContext *context = data->context;
213     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
214         qio_task_get_source(task));
215 
216     g_free(data);
217     qio_channel_tls_handshake_task(tioc, task, context);
218 
219     if (context) {
220         g_main_context_unref(context);
221     }
222 
223     return FALSE;
224 }
225 
226 void qio_channel_tls_handshake(QIOChannelTLS *ioc,
227                                QIOTaskFunc func,
228                                gpointer opaque,
229                                GDestroyNotify destroy,
230                                GMainContext *context)
231 {
232     QIOTask *task;
233 
234     task = qio_task_new(OBJECT(ioc),
235                         func, opaque, destroy);
236 
237     trace_qio_channel_tls_handshake_start(ioc);
238     qio_channel_tls_handshake_task(ioc, task, context);
239 }
240 
241 
242 static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
243 {
244 }
245 
246 
247 static void qio_channel_tls_finalize(Object *obj)
248 {
249     QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
250 
251     object_unref(OBJECT(ioc->master));
252     qcrypto_tls_session_free(ioc->session);
253 }
254 
255 
256 static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
257                                      const struct iovec *iov,
258                                      size_t niov,
259                                      int **fds,
260                                      size_t *nfds,
261                                      Error **errp)
262 {
263     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
264     size_t i;
265     ssize_t got = 0;
266 
267     for (i = 0 ; i < niov ; i++) {
268         ssize_t ret = qcrypto_tls_session_read(tioc->session,
269                                                iov[i].iov_base,
270                                                iov[i].iov_len);
271         if (ret < 0) {
272             if (errno == EAGAIN) {
273                 if (got) {
274                     return got;
275                 } else {
276                     return QIO_CHANNEL_ERR_BLOCK;
277                 }
278             }
279 
280             error_setg_errno(errp, errno,
281                              "Cannot read from TLS channel");
282             return -1;
283         }
284         got += ret;
285         if (ret < iov[i].iov_len) {
286             break;
287         }
288     }
289     return got;
290 }
291 
292 
293 static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
294                                       const struct iovec *iov,
295                                       size_t niov,
296                                       int *fds,
297                                       size_t nfds,
298                                       Error **errp)
299 {
300     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
301     size_t i;
302     ssize_t done = 0;
303 
304     for (i = 0 ; i < niov ; i++) {
305         ssize_t ret = qcrypto_tls_session_write(tioc->session,
306                                                 iov[i].iov_base,
307                                                 iov[i].iov_len);
308         if (ret <= 0) {
309             if (errno == EAGAIN) {
310                 if (done) {
311                     return done;
312                 } else {
313                     return QIO_CHANNEL_ERR_BLOCK;
314                 }
315             }
316 
317             error_setg_errno(errp, errno,
318                              "Cannot write to TLS channel");
319             return -1;
320         }
321         done += ret;
322         if (ret < iov[i].iov_len) {
323             break;
324         }
325     }
326     return done;
327 }
328 
329 static int qio_channel_tls_set_blocking(QIOChannel *ioc,
330                                         bool enabled,
331                                         Error **errp)
332 {
333     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
334 
335     return qio_channel_set_blocking(tioc->master, enabled, errp);
336 }
337 
338 static void qio_channel_tls_set_delay(QIOChannel *ioc,
339                                       bool enabled)
340 {
341     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
342 
343     qio_channel_set_delay(tioc->master, enabled);
344 }
345 
346 static void qio_channel_tls_set_cork(QIOChannel *ioc,
347                                      bool enabled)
348 {
349     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
350 
351     qio_channel_set_cork(tioc->master, enabled);
352 }
353 
354 static int qio_channel_tls_shutdown(QIOChannel *ioc,
355                                     QIOChannelShutdown how,
356                                     Error **errp)
357 {
358     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
359 
360     return qio_channel_shutdown(tioc->master, how, errp);
361 }
362 
363 static int qio_channel_tls_close(QIOChannel *ioc,
364                                  Error **errp)
365 {
366     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
367 
368     return qio_channel_close(tioc->master, errp);
369 }
370 
371 static void qio_channel_tls_set_aio_fd_handler(QIOChannel *ioc,
372                                                AioContext *ctx,
373                                                IOHandler *io_read,
374                                                IOHandler *io_write,
375                                                void *opaque)
376 {
377     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
378 
379     qio_channel_set_aio_fd_handler(tioc->master, ctx, io_read, io_write, opaque);
380 }
381 
382 static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
383                                              GIOCondition condition)
384 {
385     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
386 
387     return qio_channel_create_watch(tioc->master, condition);
388 }
389 
390 QCryptoTLSSession *
391 qio_channel_tls_get_session(QIOChannelTLS *ioc)
392 {
393     return ioc->session;
394 }
395 
396 static void qio_channel_tls_class_init(ObjectClass *klass,
397                                        void *class_data G_GNUC_UNUSED)
398 {
399     QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
400 
401     ioc_klass->io_writev = qio_channel_tls_writev;
402     ioc_klass->io_readv = qio_channel_tls_readv;
403     ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
404     ioc_klass->io_set_delay = qio_channel_tls_set_delay;
405     ioc_klass->io_set_cork = qio_channel_tls_set_cork;
406     ioc_klass->io_close = qio_channel_tls_close;
407     ioc_klass->io_shutdown = qio_channel_tls_shutdown;
408     ioc_klass->io_create_watch = qio_channel_tls_create_watch;
409     ioc_klass->io_set_aio_fd_handler = qio_channel_tls_set_aio_fd_handler;
410 }
411 
412 static const TypeInfo qio_channel_tls_info = {
413     .parent = TYPE_QIO_CHANNEL,
414     .name = TYPE_QIO_CHANNEL_TLS,
415     .instance_size = sizeof(QIOChannelTLS),
416     .instance_init = qio_channel_tls_init,
417     .instance_finalize = qio_channel_tls_finalize,
418     .class_init = qio_channel_tls_class_init,
419 };
420 
421 static void qio_channel_tls_register_types(void)
422 {
423     type_register_static(&qio_channel_tls_info);
424 }
425 
426 type_init(qio_channel_tls_register_types);
427