xref: /openbmc/qemu/io/channel-tls.c (revision b2580720) 
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 2.1 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 "qemu/module.h"
24 #include "io/channel-tls.h"
25 #include "trace.h"
26 #include "qemu/atomic.h"
27 
28 
29 static ssize_t qio_channel_tls_write_handler(const char *buf,
30                                              size_t len,
31                                              void *opaque)
32 {
33     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
34     ssize_t ret;
35 
36     ret = qio_channel_write(tioc->master, buf, len, NULL);
37     if (ret == QIO_CHANNEL_ERR_BLOCK) {
38         errno = EAGAIN;
39         return -1;
40     } else if (ret < 0) {
41         errno = EIO;
42         return -1;
43     }
44     return ret;
45 }
46 
47 static ssize_t qio_channel_tls_read_handler(char *buf,
48                                             size_t len,
49                                             void *opaque)
50 {
51     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(opaque);
52     ssize_t ret;
53 
54     ret = qio_channel_read(tioc->master, buf, len, NULL);
55     if (ret == QIO_CHANNEL_ERR_BLOCK) {
56         errno = EAGAIN;
57         return -1;
58     } else if (ret < 0) {
59         errno = EIO;
60         return -1;
61     }
62     return ret;
63 }
64 
65 
66 QIOChannelTLS *
67 qio_channel_tls_new_server(QIOChannel *master,
68                            QCryptoTLSCreds *creds,
69                            const char *aclname,
70                            Error **errp)
71 {
72     QIOChannelTLS *tioc;
73     QIOChannel *ioc;
74 
75     tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
76     ioc = QIO_CHANNEL(tioc);
77 
78     tioc->master = master;
79     ioc->follow_coroutine_ctx = master->follow_coroutine_ctx;
80     if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
81         qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
82     }
83     object_ref(OBJECT(master));
84 
85     tioc->session = qcrypto_tls_session_new(
86         creds,
87         NULL,
88         aclname,
89         QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
90         errp);
91     if (!tioc->session) {
92         goto error;
93     }
94 
95     qcrypto_tls_session_set_callbacks(
96         tioc->session,
97         qio_channel_tls_write_handler,
98         qio_channel_tls_read_handler,
99         tioc);
100 
101     trace_qio_channel_tls_new_server(tioc, master, creds, aclname);
102     return tioc;
103 
104  error:
105     object_unref(OBJECT(tioc));
106     return NULL;
107 }
108 
109 QIOChannelTLS *
110 qio_channel_tls_new_client(QIOChannel *master,
111                            QCryptoTLSCreds *creds,
112                            const char *hostname,
113                            Error **errp)
114 {
115     QIOChannelTLS *tioc;
116     QIOChannel *ioc;
117 
118     tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
119     ioc = QIO_CHANNEL(tioc);
120 
121     tioc->master = master;
122     ioc->follow_coroutine_ctx = master->follow_coroutine_ctx;
123     if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
124         qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
125     }
126     object_ref(OBJECT(master));
127 
128     tioc->session = qcrypto_tls_session_new(
129         creds,
130         hostname,
131         NULL,
132         QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
133         errp);
134     if (!tioc->session) {
135         goto error;
136     }
137 
138     qcrypto_tls_session_set_callbacks(
139         tioc->session,
140         qio_channel_tls_write_handler,
141         qio_channel_tls_read_handler,
142         tioc);
143 
144     trace_qio_channel_tls_new_client(tioc, master, creds, hostname);
145     return tioc;
146 
147  error:
148     object_unref(OBJECT(tioc));
149     return NULL;
150 }
151 
152 struct QIOChannelTLSData {
153     QIOTask *task;
154     GMainContext *context;
155 };
156 typedef struct QIOChannelTLSData QIOChannelTLSData;
157 
158 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
159                                              GIOCondition condition,
160                                              gpointer user_data);
161 
162 static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
163                                            QIOTask *task,
164                                            GMainContext *context)
165 {
166     Error *err = NULL;
167     QCryptoTLSSessionHandshakeStatus status;
168 
169     if (qcrypto_tls_session_handshake(ioc->session, &err) < 0) {
170         trace_qio_channel_tls_handshake_fail(ioc);
171         qio_task_set_error(task, err);
172         qio_task_complete(task);
173         return;
174     }
175 
176     status = qcrypto_tls_session_get_handshake_status(ioc->session);
177     if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
178         trace_qio_channel_tls_handshake_complete(ioc);
179         if (qcrypto_tls_session_check_credentials(ioc->session,
180                                                   &err) < 0) {
181             trace_qio_channel_tls_credentials_deny(ioc);
182             qio_task_set_error(task, err);
183         } else {
184             trace_qio_channel_tls_credentials_allow(ioc);
185         }
186         qio_task_complete(task);
187     } else {
188         GIOCondition condition;
189         QIOChannelTLSData *data = g_new0(typeof(*data), 1);
190 
191         data->task = task;
192         data->context = context;
193 
194         if (context) {
195             g_main_context_ref(context);
196         }
197 
198         if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
199             condition = G_IO_OUT;
200         } else {
201             condition = G_IO_IN;
202         }
203 
204         trace_qio_channel_tls_handshake_pending(ioc, status);
205         ioc->hs_ioc_tag =
206             qio_channel_add_watch_full(ioc->master,
207                                        condition,
208                                        qio_channel_tls_handshake_io,
209                                        data,
210                                        NULL,
211                                        context);
212     }
213 }
214 
215 
216 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
217                                              GIOCondition condition,
218                                              gpointer user_data)
219 {
220     QIOChannelTLSData *data = user_data;
221     QIOTask *task = data->task;
222     GMainContext *context = data->context;
223     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
224         qio_task_get_source(task));
225 
226     tioc->hs_ioc_tag = 0;
227     g_free(data);
228     qio_channel_tls_handshake_task(tioc, task, context);
229 
230     if (context) {
231         g_main_context_unref(context);
232     }
233 
234     return FALSE;
235 }
236 
237 void qio_channel_tls_handshake(QIOChannelTLS *ioc,
238                                QIOTaskFunc func,
239                                gpointer opaque,
240                                GDestroyNotify destroy,
241                                GMainContext *context)
242 {
243     QIOTask *task;
244 
245     task = qio_task_new(OBJECT(ioc),
246                         func, opaque, destroy);
247 
248     trace_qio_channel_tls_handshake_start(ioc);
249     qio_channel_tls_handshake_task(ioc, task, context);
250 }
251 
252 
253 static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
254 {
255 }
256 
257 
258 static void qio_channel_tls_finalize(Object *obj)
259 {
260     QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
261 
262     object_unref(OBJECT(ioc->master));
263     qcrypto_tls_session_free(ioc->session);
264 }
265 
266 
267 static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
268                                      const struct iovec *iov,
269                                      size_t niov,
270                                      int **fds,
271                                      size_t *nfds,
272                                      int flags,
273                                      Error **errp)
274 {
275     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
276     size_t i;
277     ssize_t got = 0;
278 
279     for (i = 0 ; i < niov ; i++) {
280         ssize_t ret = qcrypto_tls_session_read(tioc->session,
281                                                iov[i].iov_base,
282                                                iov[i].iov_len);
283         if (ret < 0) {
284             if (errno == EAGAIN) {
285                 if (got) {
286                     return got;
287                 } else {
288                     return QIO_CHANNEL_ERR_BLOCK;
289                 }
290             } else if (errno == ECONNABORTED &&
291                        (qatomic_load_acquire(&tioc->shutdown) &
292                         QIO_CHANNEL_SHUTDOWN_READ)) {
293                 return 0;
294             }
295 
296             error_setg_errno(errp, errno,
297                              "Cannot read from TLS channel");
298             return -1;
299         }
300         got += ret;
301         if (ret < iov[i].iov_len) {
302             break;
303         }
304     }
305     return got;
306 }
307 
308 
309 static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
310                                       const struct iovec *iov,
311                                       size_t niov,
312                                       int *fds,
313                                       size_t nfds,
314                                       int flags,
315                                       Error **errp)
316 {
317     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
318     size_t i;
319     ssize_t done = 0;
320 
321     for (i = 0 ; i < niov ; i++) {
322         ssize_t ret = qcrypto_tls_session_write(tioc->session,
323                                                 iov[i].iov_base,
324                                                 iov[i].iov_len);
325         if (ret <= 0) {
326             if (errno == EAGAIN) {
327                 if (done) {
328                     return done;
329                 } else {
330                     return QIO_CHANNEL_ERR_BLOCK;
331                 }
332             }
333 
334             error_setg_errno(errp, errno,
335                              "Cannot write to TLS channel");
336             return -1;
337         }
338         done += ret;
339         if (ret < iov[i].iov_len) {
340             break;
341         }
342     }
343     return done;
344 }
345 
346 static int qio_channel_tls_set_blocking(QIOChannel *ioc,
347                                         bool enabled,
348                                         Error **errp)
349 {
350     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
351 
352     return qio_channel_set_blocking(tioc->master, enabled, errp);
353 }
354 
355 static void qio_channel_tls_set_delay(QIOChannel *ioc,
356                                       bool enabled)
357 {
358     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
359 
360     qio_channel_set_delay(tioc->master, enabled);
361 }
362 
363 static void qio_channel_tls_set_cork(QIOChannel *ioc,
364                                      bool enabled)
365 {
366     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
367 
368     qio_channel_set_cork(tioc->master, enabled);
369 }
370 
371 static int qio_channel_tls_shutdown(QIOChannel *ioc,
372                                     QIOChannelShutdown how,
373                                     Error **errp)
374 {
375     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
376 
377     qatomic_or(&tioc->shutdown, how);
378 
379     return qio_channel_shutdown(tioc->master, how, errp);
380 }
381 
382 static int qio_channel_tls_close(QIOChannel *ioc,
383                                  Error **errp)
384 {
385     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
386 
387     if (tioc->hs_ioc_tag) {
388         trace_qio_channel_tls_handshake_cancel(ioc);
389         g_clear_handle_id(&tioc->hs_ioc_tag, g_source_remove);
390     }
391 
392     return qio_channel_close(tioc->master, errp);
393 }
394 
395 static void qio_channel_tls_set_aio_fd_handler(QIOChannel *ioc,
396                                                AioContext *read_ctx,
397                                                IOHandler *io_read,
398                                                AioContext *write_ctx,
399                                                IOHandler *io_write,
400                                                void *opaque)
401 {
402     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
403 
404     qio_channel_set_aio_fd_handler(tioc->master, read_ctx, io_read,
405             write_ctx, io_write, opaque);
406 }
407 
408 typedef struct QIOChannelTLSSource QIOChannelTLSSource;
409 struct QIOChannelTLSSource {
410     GSource parent;
411     QIOChannelTLS *tioc;
412 };
413 
414 static gboolean
415 qio_channel_tls_source_check(GSource *source)
416 {
417     QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source;
418 
419     return qcrypto_tls_session_check_pending(tsource->tioc->session) > 0;
420 }
421 
422 static gboolean
423 qio_channel_tls_source_prepare(GSource *source, gint *timeout)
424 {
425     *timeout = -1;
426     return qio_channel_tls_source_check(source);
427 }
428 
429 static gboolean
430 qio_channel_tls_source_dispatch(GSource *source, GSourceFunc callback,
431                                 gpointer user_data)
432 {
433     return G_SOURCE_CONTINUE;
434 }
435 
436 static void
437 qio_channel_tls_source_finalize(GSource *source)
438 {
439     QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source;
440 
441     object_unref(OBJECT(tsource->tioc));
442 }
443 
444 static GSourceFuncs qio_channel_tls_source_funcs = {
445     qio_channel_tls_source_prepare,
446     qio_channel_tls_source_check,
447     qio_channel_tls_source_dispatch,
448     qio_channel_tls_source_finalize
449 };
450 
451 static void
452 qio_channel_tls_read_watch(QIOChannelTLS *tioc, GSource *source)
453 {
454     GSource *child;
455     QIOChannelTLSSource *tlssource;
456 
457     child = g_source_new(&qio_channel_tls_source_funcs,
458                           sizeof(QIOChannelTLSSource));
459     tlssource = (QIOChannelTLSSource *)child;
460 
461     tlssource->tioc = tioc;
462     object_ref(OBJECT(tioc));
463 
464     g_source_add_child_source(source, child);
465     g_source_unref(child);
466 }
467 
468 static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
469                                              GIOCondition condition)
470 {
471     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
472     GSource *source = qio_channel_create_watch(tioc->master, condition);
473 
474     if (condition & G_IO_IN) {
475         qio_channel_tls_read_watch(tioc, source);
476     }
477 
478     return source;
479 }
480 
481 QCryptoTLSSession *
482 qio_channel_tls_get_session(QIOChannelTLS *ioc)
483 {
484     return ioc->session;
485 }
486 
487 static void qio_channel_tls_class_init(ObjectClass *klass,
488                                        void *class_data G_GNUC_UNUSED)
489 {
490     QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
491 
492     ioc_klass->io_writev = qio_channel_tls_writev;
493     ioc_klass->io_readv = qio_channel_tls_readv;
494     ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
495     ioc_klass->io_set_delay = qio_channel_tls_set_delay;
496     ioc_klass->io_set_cork = qio_channel_tls_set_cork;
497     ioc_klass->io_close = qio_channel_tls_close;
498     ioc_klass->io_shutdown = qio_channel_tls_shutdown;
499     ioc_klass->io_create_watch = qio_channel_tls_create_watch;
500     ioc_klass->io_set_aio_fd_handler = qio_channel_tls_set_aio_fd_handler;
501 }
502 
503 static const TypeInfo qio_channel_tls_info = {
504     .parent = TYPE_QIO_CHANNEL,
505     .name = TYPE_QIO_CHANNEL_TLS,
506     .instance_size = sizeof(QIOChannelTLS),
507     .instance_init = qio_channel_tls_init,
508     .instance_finalize = qio_channel_tls_finalize,
509     .class_init = qio_channel_tls_class_init,
510 };
511 
512 static void qio_channel_tls_register_types(void)
513 {
514     type_register_static(&qio_channel_tls_info);
515 }
516 
517 type_init(qio_channel_tls_register_types);
518