1 /* GIO - GLib Input, Output and Streaming Library
2 *
3 * Copyright (C) 2006-2007 Red Hat, Inc.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: Alexander Larsson <alexl@redhat.com>
19 */
20
21 #include "config.h"
22
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26 #include <errno.h>
27 #include <stdio.h>
28 #include <fcntl.h>
29
30 #include <glib.h>
31 #include <glib/gstdio.h>
32 #include <glib/glib-unix.h>
33 #include "gioerror.h"
34 #include "gunixinputstream.h"
35 #include "gcancellable.h"
36 #include "gasynchelper.h"
37 #include "gfiledescriptorbased.h"
38 #include "glibintl.h"
39
40
41 /**
42 * SECTION:gunixinputstream
43 * @short_description: Streaming input operations for UNIX file descriptors
44 * @include: gio/gunixinputstream.h
45 * @see_also: #GInputStream
46 *
47 * #GUnixInputStream implements #GInputStream for reading from a UNIX
48 * file descriptor, including asynchronous operations. (If the file
49 * descriptor refers to a socket or pipe, this will use poll() to do
50 * asynchronous I/O. If it refers to a regular file, it will fall back
51 * to doing asynchronous I/O in another thread.)
52 *
53 * Note that `<gio/gunixinputstream.h>` belongs to the UNIX-specific GIO
54 * interfaces, thus you have to use the `gio-unix-2.0.pc` pkg-config
55 * file when using it.
56 */
57
58 enum {
59 PROP_0,
60 PROP_FD,
61 PROP_CLOSE_FD
62 };
63
64 struct _GUnixInputStreamPrivate {
65 int fd;
66 guint close_fd : 1;
67 guint is_pipe_or_socket : 1;
68 };
69
70 static void g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
71 static void g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
72
73 G_DEFINE_TYPE_WITH_CODE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM,
74 G_ADD_PRIVATE (GUnixInputStream)
75 G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
76 g_unix_input_stream_pollable_iface_init)
77 G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
78 g_unix_input_stream_file_descriptor_based_iface_init)
79 )
80
81 static void g_unix_input_stream_set_property (GObject *object,
82 guint prop_id,
83 const GValue *value,
84 GParamSpec *pspec);
85 static void g_unix_input_stream_get_property (GObject *object,
86 guint prop_id,
87 GValue *value,
88 GParamSpec *pspec);
89 static gssize g_unix_input_stream_read (GInputStream *stream,
90 void *buffer,
91 gsize count,
92 GCancellable *cancellable,
93 GError **error);
94 static gboolean g_unix_input_stream_close (GInputStream *stream,
95 GCancellable *cancellable,
96 GError **error);
97 static void g_unix_input_stream_skip_async (GInputStream *stream,
98 gsize count,
99 int io_priority,
100 GCancellable *cancellable,
101 GAsyncReadyCallback callback,
102 gpointer data);
103 static gssize g_unix_input_stream_skip_finish (GInputStream *stream,
104 GAsyncResult *result,
105 GError **error);
106 static void g_unix_input_stream_close_async (GInputStream *stream,
107 int io_priority,
108 GCancellable *cancellable,
109 GAsyncReadyCallback callback,
110 gpointer data);
111 static gboolean g_unix_input_stream_close_finish (GInputStream *stream,
112 GAsyncResult *result,
113 GError **error);
114
115 static gboolean g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream);
116 static gboolean g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream);
117 static GSource *g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
118 GCancellable *cancellable);
119
120 static void
g_unix_input_stream_class_init(GUnixInputStreamClass * klass)121 g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
122 {
123 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
124 GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
125
126 gobject_class->get_property = g_unix_input_stream_get_property;
127 gobject_class->set_property = g_unix_input_stream_set_property;
128
129 stream_class->read_fn = g_unix_input_stream_read;
130 stream_class->close_fn = g_unix_input_stream_close;
131 if (0)
132 {
133 /* TODO: Implement instead of using fallbacks */
134 stream_class->skip_async = g_unix_input_stream_skip_async;
135 stream_class->skip_finish = g_unix_input_stream_skip_finish;
136 }
137 stream_class->close_async = g_unix_input_stream_close_async;
138 stream_class->close_finish = g_unix_input_stream_close_finish;
139
140 /**
141 * GUnixInputStream:fd:
142 *
143 * The file descriptor that the stream reads from.
144 *
145 * Since: 2.20
146 */
147 g_object_class_install_property (gobject_class,
148 PROP_FD,
149 g_param_spec_int ("fd",
150 P_("File descriptor"),
151 P_("The file descriptor to read from"),
152 G_MININT, G_MAXINT, -1,
153 G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
154
155 /**
156 * GUnixInputStream:close-fd:
157 *
158 * Whether to close the file descriptor when the stream is closed.
159 *
160 * Since: 2.20
161 */
162 g_object_class_install_property (gobject_class,
163 PROP_CLOSE_FD,
164 g_param_spec_boolean ("close-fd",
165 P_("Close file descriptor"),
166 P_("Whether to close the file descriptor when the stream is closed"),
167 TRUE,
168 G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
169 }
170
171 static void
g_unix_input_stream_pollable_iface_init(GPollableInputStreamInterface * iface)172 g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
173 {
174 iface->can_poll = g_unix_input_stream_pollable_can_poll;
175 iface->is_readable = g_unix_input_stream_pollable_is_readable;
176 iface->create_source = g_unix_input_stream_pollable_create_source;
177 }
178
179 static void
g_unix_input_stream_file_descriptor_based_iface_init(GFileDescriptorBasedIface * iface)180 g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
181 {
182 iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_input_stream_get_fd;
183 }
184
185 static void
g_unix_input_stream_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)186 g_unix_input_stream_set_property (GObject *object,
187 guint prop_id,
188 const GValue *value,
189 GParamSpec *pspec)
190 {
191 GUnixInputStream *unix_stream;
192
193 unix_stream = G_UNIX_INPUT_STREAM (object);
194
195 switch (prop_id)
196 {
197 case PROP_FD:
198 unix_stream->priv->fd = g_value_get_int (value);
199 if (lseek (unix_stream->priv->fd, 0, SEEK_CUR) == -1 && errno == ESPIPE)
200 unix_stream->priv->is_pipe_or_socket = TRUE;
201 else
202 unix_stream->priv->is_pipe_or_socket = FALSE;
203 break;
204 case PROP_CLOSE_FD:
205 unix_stream->priv->close_fd = g_value_get_boolean (value);
206 break;
207 default:
208 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
209 break;
210 }
211 }
212
213 static void
g_unix_input_stream_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)214 g_unix_input_stream_get_property (GObject *object,
215 guint prop_id,
216 GValue *value,
217 GParamSpec *pspec)
218 {
219 GUnixInputStream *unix_stream;
220
221 unix_stream = G_UNIX_INPUT_STREAM (object);
222
223 switch (prop_id)
224 {
225 case PROP_FD:
226 g_value_set_int (value, unix_stream->priv->fd);
227 break;
228 case PROP_CLOSE_FD:
229 g_value_set_boolean (value, unix_stream->priv->close_fd);
230 break;
231 default:
232 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
233 }
234 }
235
236 static void
g_unix_input_stream_init(GUnixInputStream * unix_stream)237 g_unix_input_stream_init (GUnixInputStream *unix_stream)
238 {
239 unix_stream->priv = g_unix_input_stream_get_instance_private (unix_stream);
240 unix_stream->priv->fd = -1;
241 unix_stream->priv->close_fd = TRUE;
242 }
243
244 /**
245 * g_unix_input_stream_new:
246 * @fd: a UNIX file descriptor
247 * @close_fd: %TRUE to close the file descriptor when done
248 *
249 * Creates a new #GUnixInputStream for the given @fd.
250 *
251 * If @close_fd is %TRUE, the file descriptor will be closed
252 * when the stream is closed.
253 *
254 * Returns: a new #GUnixInputStream
255 **/
256 GInputStream *
g_unix_input_stream_new(gint fd,gboolean close_fd)257 g_unix_input_stream_new (gint fd,
258 gboolean close_fd)
259 {
260 GUnixInputStream *stream;
261
262 g_return_val_if_fail (fd != -1, NULL);
263
264 stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
265 "fd", fd,
266 "close-fd", close_fd,
267 NULL);
268
269 return G_INPUT_STREAM (stream);
270 }
271
272 /**
273 * g_unix_input_stream_set_close_fd:
274 * @stream: a #GUnixInputStream
275 * @close_fd: %TRUE to close the file descriptor when done
276 *
277 * Sets whether the file descriptor of @stream shall be closed
278 * when the stream is closed.
279 *
280 * Since: 2.20
281 */
282 void
g_unix_input_stream_set_close_fd(GUnixInputStream * stream,gboolean close_fd)283 g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
284 gboolean close_fd)
285 {
286 g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
287
288 close_fd = close_fd != FALSE;
289 if (stream->priv->close_fd != close_fd)
290 {
291 stream->priv->close_fd = close_fd;
292 g_object_notify (G_OBJECT (stream), "close-fd");
293 }
294 }
295
296 /**
297 * g_unix_input_stream_get_close_fd:
298 * @stream: a #GUnixInputStream
299 *
300 * Returns whether the file descriptor of @stream will be
301 * closed when the stream is closed.
302 *
303 * Returns: %TRUE if the file descriptor is closed when done
304 *
305 * Since: 2.20
306 */
307 gboolean
g_unix_input_stream_get_close_fd(GUnixInputStream * stream)308 g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
309 {
310 g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
311
312 return stream->priv->close_fd;
313 }
314
315 /**
316 * g_unix_input_stream_get_fd:
317 * @stream: a #GUnixInputStream
318 *
319 * Return the UNIX file descriptor that the stream reads from.
320 *
321 * Returns: The file descriptor of @stream
322 *
323 * Since: 2.20
324 */
325 gint
g_unix_input_stream_get_fd(GUnixInputStream * stream)326 g_unix_input_stream_get_fd (GUnixInputStream *stream)
327 {
328 g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
329
330 return stream->priv->fd;
331 }
332
333 static gssize
g_unix_input_stream_read(GInputStream * stream,void * buffer,gsize count,GCancellable * cancellable,GError ** error)334 g_unix_input_stream_read (GInputStream *stream,
335 void *buffer,
336 gsize count,
337 GCancellable *cancellable,
338 GError **error)
339 {
340 GUnixInputStream *unix_stream;
341 gssize res = -1;
342 GPollFD poll_fds[2];
343 int nfds;
344 int poll_ret;
345
346 unix_stream = G_UNIX_INPUT_STREAM (stream);
347
348 poll_fds[0].fd = unix_stream->priv->fd;
349 poll_fds[0].events = G_IO_IN;
350 if (unix_stream->priv->is_pipe_or_socket &&
351 g_cancellable_make_pollfd (cancellable, &poll_fds[1]))
352 nfds = 2;
353 else
354 nfds = 1;
355
356 while (1)
357 {
358 int errsv;
359
360 poll_fds[0].revents = poll_fds[1].revents = 0;
361 do
362 {
363 poll_ret = g_poll (poll_fds, nfds, -1);
364 errsv = errno;
365 }
366 while (poll_ret == -1 && errsv == EINTR);
367
368 if (poll_ret == -1)
369 {
370 g_set_error (error, G_IO_ERROR,
371 g_io_error_from_errno (errsv),
372 _("Error reading from file descriptor: %s"),
373 g_strerror (errsv));
374 break;
375 }
376
377 if (g_cancellable_set_error_if_cancelled (cancellable, error))
378 break;
379
380 if (!poll_fds[0].revents)
381 continue;
382
383 res = read (unix_stream->priv->fd, buffer, count);
384 if (res == -1)
385 {
386 int errsv = errno;
387
388 if (errsv == EINTR || errsv == EAGAIN)
389 continue;
390
391 g_set_error (error, G_IO_ERROR,
392 g_io_error_from_errno (errsv),
393 _("Error reading from file descriptor: %s"),
394 g_strerror (errsv));
395 }
396
397 break;
398 }
399
400 if (nfds == 2)
401 g_cancellable_release_fd (cancellable);
402 return res;
403 }
404
405 static gboolean
g_unix_input_stream_close(GInputStream * stream,GCancellable * cancellable,GError ** error)406 g_unix_input_stream_close (GInputStream *stream,
407 GCancellable *cancellable,
408 GError **error)
409 {
410 GUnixInputStream *unix_stream;
411 int res;
412
413 unix_stream = G_UNIX_INPUT_STREAM (stream);
414
415 if (!unix_stream->priv->close_fd)
416 return TRUE;
417
418 /* This might block during the close. Doesn't seem to be a way to avoid it though. */
419 res = close (unix_stream->priv->fd);
420 if (res == -1)
421 {
422 int errsv = errno;
423
424 g_set_error (error, G_IO_ERROR,
425 g_io_error_from_errno (errsv),
426 _("Error closing file descriptor: %s"),
427 g_strerror (errsv));
428 }
429
430 return res != -1;
431 }
432
433 static void
g_unix_input_stream_skip_async(GInputStream * stream,gsize count,int io_priority,GCancellable * cancellable,GAsyncReadyCallback callback,gpointer data)434 g_unix_input_stream_skip_async (GInputStream *stream,
435 gsize count,
436 int io_priority,
437 GCancellable *cancellable,
438 GAsyncReadyCallback callback,
439 gpointer data)
440 {
441 g_warn_if_reached ();
442 /* TODO: Not implemented */
443 }
444
445 static gssize
g_unix_input_stream_skip_finish(GInputStream * stream,GAsyncResult * result,GError ** error)446 g_unix_input_stream_skip_finish (GInputStream *stream,
447 GAsyncResult *result,
448 GError **error)
449 {
450 g_warn_if_reached ();
451 return 0;
452 /* TODO: Not implemented */
453 }
454
455 static void
g_unix_input_stream_close_async(GInputStream * stream,int io_priority,GCancellable * cancellable,GAsyncReadyCallback callback,gpointer user_data)456 g_unix_input_stream_close_async (GInputStream *stream,
457 int io_priority,
458 GCancellable *cancellable,
459 GAsyncReadyCallback callback,
460 gpointer user_data)
461 {
462 GTask *task;
463 GError *error = NULL;
464
465 task = g_task_new (stream, cancellable, callback, user_data);
466 g_task_set_source_tag (task, g_unix_input_stream_close_async);
467 g_task_set_priority (task, io_priority);
468
469 if (g_unix_input_stream_close (stream, cancellable, &error))
470 g_task_return_boolean (task, TRUE);
471 else
472 g_task_return_error (task, error);
473 g_object_unref (task);
474 }
475
476 static gboolean
g_unix_input_stream_close_finish(GInputStream * stream,GAsyncResult * result,GError ** error)477 g_unix_input_stream_close_finish (GInputStream *stream,
478 GAsyncResult *result,
479 GError **error)
480 {
481 g_return_val_if_fail (g_task_is_valid (result, stream), FALSE);
482
483 return g_task_propagate_boolean (G_TASK (result), error);
484 }
485
486 static gboolean
g_unix_input_stream_pollable_can_poll(GPollableInputStream * stream)487 g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream)
488 {
489 return G_UNIX_INPUT_STREAM (stream)->priv->is_pipe_or_socket;
490 }
491
492 static gboolean
g_unix_input_stream_pollable_is_readable(GPollableInputStream * stream)493 g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream)
494 {
495 GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
496 GPollFD poll_fd;
497 gint result;
498
499 poll_fd.fd = unix_stream->priv->fd;
500 poll_fd.events = G_IO_IN;
501 poll_fd.revents = 0;
502
503 do
504 result = g_poll (&poll_fd, 1, 0);
505 while (result == -1 && errno == EINTR);
506
507 return poll_fd.revents != 0;
508 }
509
510 static GSource *
g_unix_input_stream_pollable_create_source(GPollableInputStream * stream,GCancellable * cancellable)511 g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
512 GCancellable *cancellable)
513 {
514 GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
515 GSource *inner_source, *cancellable_source, *pollable_source;
516
517 pollable_source = g_pollable_source_new (G_OBJECT (stream));
518
519 inner_source = g_unix_fd_source_new (unix_stream->priv->fd, G_IO_IN);
520 g_source_set_dummy_callback (inner_source);
521 g_source_add_child_source (pollable_source, inner_source);
522 g_source_unref (inner_source);
523
524 if (cancellable)
525 {
526 cancellable_source = g_cancellable_source_new (cancellable);
527 g_source_set_dummy_callback (cancellable_source);
528 g_source_add_child_source (pollable_source, cancellable_source);
529 g_source_unref (cancellable_source);
530 }
531
532 return pollable_source;
533 }
534