xref: /openbmc/qemu/io/channel-tls.c (revision edf64786) 
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 *ioc;
73 
74     ioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
75 
76     ioc->master = master;
77     object_ref(OBJECT(master));
78 
79     ioc->session = qcrypto_tls_session_new(
80         creds,
81         NULL,
82         aclname,
83         QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
84         errp);
85     if (!ioc->session) {
86         goto error;
87     }
88 
89     qcrypto_tls_session_set_callbacks(
90         ioc->session,
91         qio_channel_tls_write_handler,
92         qio_channel_tls_read_handler,
93         ioc);
94 
95     trace_qio_channel_tls_new_server(ioc, master, creds, aclname);
96     return ioc;
97 
98  error:
99     object_unref(OBJECT(ioc));
100     return NULL;
101 }
102 
103 QIOChannelTLS *
104 qio_channel_tls_new_client(QIOChannel *master,
105                            QCryptoTLSCreds *creds,
106                            const char *hostname,
107                            Error **errp)
108 {
109     QIOChannelTLS *tioc;
110     QIOChannel *ioc;
111 
112     tioc = QIO_CHANNEL_TLS(object_new(TYPE_QIO_CHANNEL_TLS));
113     ioc = QIO_CHANNEL(tioc);
114 
115     tioc->master = master;
116     if (qio_channel_has_feature(master, QIO_CHANNEL_FEATURE_SHUTDOWN)) {
117         qio_channel_set_feature(ioc, QIO_CHANNEL_FEATURE_SHUTDOWN);
118     }
119     object_ref(OBJECT(master));
120 
121     tioc->session = qcrypto_tls_session_new(
122         creds,
123         hostname,
124         NULL,
125         QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT,
126         errp);
127     if (!tioc->session) {
128         goto error;
129     }
130 
131     qcrypto_tls_session_set_callbacks(
132         tioc->session,
133         qio_channel_tls_write_handler,
134         qio_channel_tls_read_handler,
135         tioc);
136 
137     trace_qio_channel_tls_new_client(tioc, master, creds, hostname);
138     return tioc;
139 
140  error:
141     object_unref(OBJECT(tioc));
142     return NULL;
143 }
144 
145 struct QIOChannelTLSData {
146     QIOTask *task;
147     GMainContext *context;
148 };
149 typedef struct QIOChannelTLSData QIOChannelTLSData;
150 
151 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
152                                              GIOCondition condition,
153                                              gpointer user_data);
154 
155 static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
156                                            QIOTask *task,
157                                            GMainContext *context)
158 {
159     Error *err = NULL;
160     QCryptoTLSSessionHandshakeStatus status;
161 
162     if (qcrypto_tls_session_handshake(ioc->session, &err) < 0) {
163         trace_qio_channel_tls_handshake_fail(ioc);
164         qio_task_set_error(task, err);
165         qio_task_complete(task);
166         return;
167     }
168 
169     status = qcrypto_tls_session_get_handshake_status(ioc->session);
170     if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
171         trace_qio_channel_tls_handshake_complete(ioc);
172         if (qcrypto_tls_session_check_credentials(ioc->session,
173                                                   &err) < 0) {
174             trace_qio_channel_tls_credentials_deny(ioc);
175             qio_task_set_error(task, err);
176         } else {
177             trace_qio_channel_tls_credentials_allow(ioc);
178         }
179         qio_task_complete(task);
180     } else {
181         GIOCondition condition;
182         QIOChannelTLSData *data = g_new0(typeof(*data), 1);
183 
184         data->task = task;
185         data->context = context;
186 
187         if (context) {
188             g_main_context_ref(context);
189         }
190 
191         if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
192             condition = G_IO_OUT;
193         } else {
194             condition = G_IO_IN;
195         }
196 
197         trace_qio_channel_tls_handshake_pending(ioc, status);
198         qio_channel_add_watch_full(ioc->master,
199                                    condition,
200                                    qio_channel_tls_handshake_io,
201                                    data,
202                                    NULL,
203                                    context);
204     }
205 }
206 
207 
208 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
209                                              GIOCondition condition,
210                                              gpointer user_data)
211 {
212     QIOChannelTLSData *data = user_data;
213     QIOTask *task = data->task;
214     GMainContext *context = data->context;
215     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
216         qio_task_get_source(task));
217 
218     g_free(data);
219     qio_channel_tls_handshake_task(tioc, task, context);
220 
221     if (context) {
222         g_main_context_unref(context);
223     }
224 
225     return FALSE;
226 }
227 
228 void qio_channel_tls_handshake(QIOChannelTLS *ioc,
229                                QIOTaskFunc func,
230                                gpointer opaque,
231                                GDestroyNotify destroy,
232                                GMainContext *context)
233 {
234     QIOTask *task;
235 
236     task = qio_task_new(OBJECT(ioc),
237                         func, opaque, destroy);
238 
239     trace_qio_channel_tls_handshake_start(ioc);
240     qio_channel_tls_handshake_task(ioc, task, context);
241 }
242 
243 
244 static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
245 {
246 }
247 
248 
249 static void qio_channel_tls_finalize(Object *obj)
250 {
251     QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
252 
253     object_unref(OBJECT(ioc->master));
254     qcrypto_tls_session_free(ioc->session);
255 }
256 
257 
258 static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
259                                      const struct iovec *iov,
260                                      size_t niov,
261                                      int **fds,
262                                      size_t *nfds,
263                                      Error **errp)
264 {
265     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
266     size_t i;
267     ssize_t got = 0;
268 
269     for (i = 0 ; i < niov ; i++) {
270         ssize_t ret = qcrypto_tls_session_read(tioc->session,
271                                                iov[i].iov_base,
272                                                iov[i].iov_len);
273         if (ret < 0) {
274             if (errno == EAGAIN) {
275                 if (got) {
276                     return got;
277                 } else {
278                     return QIO_CHANNEL_ERR_BLOCK;
279                 }
280             } else if (errno == ECONNABORTED &&
281                        (qatomic_load_acquire(&tioc->shutdown) &
282                         QIO_CHANNEL_SHUTDOWN_READ)) {
283                 return 0;
284             }
285 
286             error_setg_errno(errp, errno,
287                              "Cannot read from TLS channel");
288             return -1;
289         }
290         got += ret;
291         if (ret < iov[i].iov_len) {
292             break;
293         }
294     }
295     return got;
296 }
297 
298 
299 static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
300                                       const struct iovec *iov,
301                                       size_t niov,
302                                       int *fds,
303                                       size_t nfds,
304                                       Error **errp)
305 {
306     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
307     size_t i;
308     ssize_t done = 0;
309 
310     for (i = 0 ; i < niov ; i++) {
311         ssize_t ret = qcrypto_tls_session_write(tioc->session,
312                                                 iov[i].iov_base,
313                                                 iov[i].iov_len);
314         if (ret <= 0) {
315             if (errno == EAGAIN) {
316                 if (done) {
317                     return done;
318                 } else {
319                     return QIO_CHANNEL_ERR_BLOCK;
320                 }
321             }
322 
323             error_setg_errno(errp, errno,
324                              "Cannot write to TLS channel");
325             return -1;
326         }
327         done += ret;
328         if (ret < iov[i].iov_len) {
329             break;
330         }
331     }
332     return done;
333 }
334 
335 static int qio_channel_tls_set_blocking(QIOChannel *ioc,
336                                         bool enabled,
337                                         Error **errp)
338 {
339     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
340 
341     return qio_channel_set_blocking(tioc->master, enabled, errp);
342 }
343 
344 static void qio_channel_tls_set_delay(QIOChannel *ioc,
345                                       bool enabled)
346 {
347     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
348 
349     qio_channel_set_delay(tioc->master, enabled);
350 }
351 
352 static void qio_channel_tls_set_cork(QIOChannel *ioc,
353                                      bool enabled)
354 {
355     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
356 
357     qio_channel_set_cork(tioc->master, enabled);
358 }
359 
360 static int qio_channel_tls_shutdown(QIOChannel *ioc,
361                                     QIOChannelShutdown how,
362                                     Error **errp)
363 {
364     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
365 
366     qatomic_or(&tioc->shutdown, how);
367 
368     return qio_channel_shutdown(tioc->master, how, errp);
369 }
370 
371 static int qio_channel_tls_close(QIOChannel *ioc,
372                                  Error **errp)
373 {
374     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
375 
376     return qio_channel_close(tioc->master, errp);
377 }
378 
379 static void qio_channel_tls_set_aio_fd_handler(QIOChannel *ioc,
380                                                AioContext *ctx,
381                                                IOHandler *io_read,
382                                                IOHandler *io_write,
383                                                void *opaque)
384 {
385     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
386 
387     qio_channel_set_aio_fd_handler(tioc->master, ctx, io_read, io_write, opaque);
388 }
389 
390 static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
391                                              GIOCondition condition)
392 {
393     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
394 
395     return qio_channel_create_watch(tioc->master, condition);
396 }
397 
398 QCryptoTLSSession *
399 qio_channel_tls_get_session(QIOChannelTLS *ioc)
400 {
401     return ioc->session;
402 }
403 
404 static void qio_channel_tls_class_init(ObjectClass *klass,
405                                        void *class_data G_GNUC_UNUSED)
406 {
407     QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
408 
409     ioc_klass->io_writev = qio_channel_tls_writev;
410     ioc_klass->io_readv = qio_channel_tls_readv;
411     ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
412     ioc_klass->io_set_delay = qio_channel_tls_set_delay;
413     ioc_klass->io_set_cork = qio_channel_tls_set_cork;
414     ioc_klass->io_close = qio_channel_tls_close;
415     ioc_klass->io_shutdown = qio_channel_tls_shutdown;
416     ioc_klass->io_create_watch = qio_channel_tls_create_watch;
417     ioc_klass->io_set_aio_fd_handler = qio_channel_tls_set_aio_fd_handler;
418 }
419 
420 static const TypeInfo qio_channel_tls_info = {
421     .parent = TYPE_QIO_CHANNEL,
422     .name = TYPE_QIO_CHANNEL_TLS,
423     .instance_size = sizeof(QIOChannelTLS),
424     .instance_init = qio_channel_tls_init,
425     .instance_finalize = qio_channel_tls_finalize,
426     .class_init = qio_channel_tls_class_init,
427 };
428 
429 static void qio_channel_tls_register_types(void)
430 {
431     type_register_static(&qio_channel_tls_info);
432 }
433 
434 type_init(qio_channel_tls_register_types);
435