xref: /qemu/io/channel-tls.c (revision 20daa90a) 
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 
144 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
145                                              GIOCondition condition,
146                                              gpointer user_data);
147 
148 static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc,
149                                            QIOTask *task)
150 {
151     Error *err = NULL;
152     QCryptoTLSSessionHandshakeStatus status;
153 
154     if (qcrypto_tls_session_handshake(ioc->session, &err) < 0) {
155         trace_qio_channel_tls_handshake_fail(ioc);
156         qio_task_set_error(task, err);
157         qio_task_complete(task);
158         return;
159     }
160 
161     status = qcrypto_tls_session_get_handshake_status(ioc->session);
162     if (status == QCRYPTO_TLS_HANDSHAKE_COMPLETE) {
163         trace_qio_channel_tls_handshake_complete(ioc);
164         if (qcrypto_tls_session_check_credentials(ioc->session,
165                                                   &err) < 0) {
166             trace_qio_channel_tls_credentials_deny(ioc);
167             qio_task_set_error(task, err);
168         } else {
169             trace_qio_channel_tls_credentials_allow(ioc);
170         }
171         qio_task_complete(task);
172     } else {
173         GIOCondition condition;
174         if (status == QCRYPTO_TLS_HANDSHAKE_SENDING) {
175             condition = G_IO_OUT;
176         } else {
177             condition = G_IO_IN;
178         }
179 
180         trace_qio_channel_tls_handshake_pending(ioc, status);
181         qio_channel_add_watch(ioc->master,
182                               condition,
183                               qio_channel_tls_handshake_io,
184                               task,
185                               NULL);
186     }
187 }
188 
189 
190 static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc,
191                                              GIOCondition condition,
192                                              gpointer user_data)
193 {
194     QIOTask *task = user_data;
195     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(
196         qio_task_get_source(task));
197 
198     qio_channel_tls_handshake_task(
199        tioc, task);
200 
201     return FALSE;
202 }
203 
204 void qio_channel_tls_handshake(QIOChannelTLS *ioc,
205                                QIOTaskFunc func,
206                                gpointer opaque,
207                                GDestroyNotify destroy)
208 {
209     QIOTask *task;
210 
211     task = qio_task_new(OBJECT(ioc),
212                         func, opaque, destroy);
213 
214     trace_qio_channel_tls_handshake_start(ioc);
215     qio_channel_tls_handshake_task(ioc, task);
216 }
217 
218 
219 static void qio_channel_tls_init(Object *obj G_GNUC_UNUSED)
220 {
221 }
222 
223 
224 static void qio_channel_tls_finalize(Object *obj)
225 {
226     QIOChannelTLS *ioc = QIO_CHANNEL_TLS(obj);
227 
228     object_unref(OBJECT(ioc->master));
229     qcrypto_tls_session_free(ioc->session);
230 }
231 
232 
233 static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
234                                      const struct iovec *iov,
235                                      size_t niov,
236                                      int **fds,
237                                      size_t *nfds,
238                                      Error **errp)
239 {
240     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
241     size_t i;
242     ssize_t got = 0;
243 
244     for (i = 0 ; i < niov ; i++) {
245         ssize_t ret = qcrypto_tls_session_read(tioc->session,
246                                                iov[i].iov_base,
247                                                iov[i].iov_len);
248         if (ret < 0) {
249             if (errno == EAGAIN) {
250                 if (got) {
251                     return got;
252                 } else {
253                     return QIO_CHANNEL_ERR_BLOCK;
254                 }
255             }
256 
257             error_setg_errno(errp, errno,
258                              "Cannot read from TLS channel");
259             return -1;
260         }
261         got += ret;
262         if (ret < iov[i].iov_len) {
263             break;
264         }
265     }
266     return got;
267 }
268 
269 
270 static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
271                                       const struct iovec *iov,
272                                       size_t niov,
273                                       int *fds,
274                                       size_t nfds,
275                                       Error **errp)
276 {
277     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
278     size_t i;
279     ssize_t done = 0;
280 
281     for (i = 0 ; i < niov ; i++) {
282         ssize_t ret = qcrypto_tls_session_write(tioc->session,
283                                                 iov[i].iov_base,
284                                                 iov[i].iov_len);
285         if (ret <= 0) {
286             if (errno == EAGAIN) {
287                 if (done) {
288                     return done;
289                 } else {
290                     return QIO_CHANNEL_ERR_BLOCK;
291                 }
292             }
293 
294             error_setg_errno(errp, errno,
295                              "Cannot write to TLS channel");
296             return -1;
297         }
298         done += ret;
299         if (ret < iov[i].iov_len) {
300             break;
301         }
302     }
303     return done;
304 }
305 
306 static int qio_channel_tls_set_blocking(QIOChannel *ioc,
307                                         bool enabled,
308                                         Error **errp)
309 {
310     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
311 
312     return qio_channel_set_blocking(tioc->master, enabled, errp);
313 }
314 
315 static void qio_channel_tls_set_delay(QIOChannel *ioc,
316                                       bool enabled)
317 {
318     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
319 
320     qio_channel_set_delay(tioc->master, enabled);
321 }
322 
323 static void qio_channel_tls_set_cork(QIOChannel *ioc,
324                                      bool enabled)
325 {
326     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
327 
328     qio_channel_set_cork(tioc->master, enabled);
329 }
330 
331 static int qio_channel_tls_shutdown(QIOChannel *ioc,
332                                     QIOChannelShutdown how,
333                                     Error **errp)
334 {
335     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
336 
337     return qio_channel_shutdown(tioc->master, how, errp);
338 }
339 
340 static int qio_channel_tls_close(QIOChannel *ioc,
341                                  Error **errp)
342 {
343     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
344 
345     return qio_channel_close(tioc->master, errp);
346 }
347 
348 static GSource *qio_channel_tls_create_watch(QIOChannel *ioc,
349                                              GIOCondition condition)
350 {
351     QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc);
352 
353     return qio_channel_create_watch(tioc->master, condition);
354 }
355 
356 QCryptoTLSSession *
357 qio_channel_tls_get_session(QIOChannelTLS *ioc)
358 {
359     return ioc->session;
360 }
361 
362 static void qio_channel_tls_class_init(ObjectClass *klass,
363                                        void *class_data G_GNUC_UNUSED)
364 {
365     QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
366 
367     ioc_klass->io_writev = qio_channel_tls_writev;
368     ioc_klass->io_readv = qio_channel_tls_readv;
369     ioc_klass->io_set_blocking = qio_channel_tls_set_blocking;
370     ioc_klass->io_set_delay = qio_channel_tls_set_delay;
371     ioc_klass->io_set_cork = qio_channel_tls_set_cork;
372     ioc_klass->io_close = qio_channel_tls_close;
373     ioc_klass->io_shutdown = qio_channel_tls_shutdown;
374     ioc_klass->io_create_watch = qio_channel_tls_create_watch;
375 }
376 
377 static const TypeInfo qio_channel_tls_info = {
378     .parent = TYPE_QIO_CHANNEL,
379     .name = TYPE_QIO_CHANNEL_TLS,
380     .instance_size = sizeof(QIOChannelTLS),
381     .instance_init = qio_channel_tls_init,
382     .instance_finalize = qio_channel_tls_finalize,
383     .class_init = qio_channel_tls_class_init,
384 };
385 
386 static void qio_channel_tls_register_types(void)
387 {
388     type_register_static(&qio_channel_tls_info);
389 }
390 
391 type_init(qio_channel_tls_register_types);
392