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 <unistd.h>
24#include <errno.h>
25#include <stdio.h>
26
27#include <glib.h>
28#include <glib/gstdio.h>
29#include <glib/glib-unix.h>
30#include "gioerror.h"
31#include "gunixinputstream.h"
32#include "gcancellable.h"
33#include "gasynchelper.h"
34#include "gfiledescriptorbased.h"
35#include "glibintl.h"
36#include "giounix-private.h"
37
38
39/**
40 * SECTION:gunixinputstream
41 * @short_description: Streaming input operations for UNIX file descriptors
42 * @include: gio/gunixinputstream.h
43 * @see_also: #GInputStream
44 *
45 * #GUnixInputStream implements #GInputStream for reading from a UNIX
46 * file descriptor, including asynchronous operations. (If the file
47 * descriptor refers to a socket or pipe, this will use poll() to do
48 * asynchronous I/O. If it refers to a regular file, it will fall back
49 * to doing asynchronous I/O in another thread.)
50 *
51 * Note that `<gio/gunixinputstream.h>` belongs to the UNIX-specific GIO
52 * interfaces, thus you have to use the `gio-unix-2.0.pc` pkg-config
53 * file when using it.
54 */
55
56enum {
57 PROP_0,
58 PROP_FD,
59 PROP_CLOSE_FD
60};
61
62struct _GUnixInputStreamPrivate {
63 int fd;
64 guint close_fd : 1;
65 guint can_poll : 1;
66};
67
68static void g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface);
69static void g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface);
70
71G_DEFINE_TYPE_WITH_CODE (GUnixInputStream, g_unix_input_stream, G_TYPE_INPUT_STREAM,
72 G_ADD_PRIVATE (GUnixInputStream)
73 G_IMPLEMENT_INTERFACE (G_TYPE_POLLABLE_INPUT_STREAM,
74 g_unix_input_stream_pollable_iface_init)
75 G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
76 g_unix_input_stream_file_descriptor_based_iface_init)
77 )
78
79static void g_unix_input_stream_set_property (GObject *object,
80 guint prop_id,
81 const GValue *value,
82 GParamSpec *pspec);
83static void g_unix_input_stream_get_property (GObject *object,
84 guint prop_id,
85 GValue *value,
86 GParamSpec *pspec);
87static gssize g_unix_input_stream_read (GInputStream *stream,
88 void *buffer,
89 gsize count,
90 GCancellable *cancellable,
91 GError **error);
92static gboolean g_unix_input_stream_close (GInputStream *stream,
93 GCancellable *cancellable,
94 GError **error);
95static void g_unix_input_stream_skip_async (GInputStream *stream,
96 gsize count,
97 int io_priority,
98 GCancellable *cancellable,
99 GAsyncReadyCallback callback,
100 gpointer data);
101static gssize g_unix_input_stream_skip_finish (GInputStream *stream,
102 GAsyncResult *result,
103 GError **error);
104
105static gboolean g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream);
106static gboolean g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream);
107static GSource *g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
108 GCancellable *cancellable);
109
110static void
111g_unix_input_stream_class_init (GUnixInputStreamClass *klass)
112{
113 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
114 GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
115
116 gobject_class->get_property = g_unix_input_stream_get_property;
117 gobject_class->set_property = g_unix_input_stream_set_property;
118
119 stream_class->read_fn = g_unix_input_stream_read;
120 stream_class->close_fn = g_unix_input_stream_close;
121 if (0)
122 {
123 /* TODO: Implement instead of using fallbacks */
124 stream_class->skip_async = g_unix_input_stream_skip_async;
125 stream_class->skip_finish = g_unix_input_stream_skip_finish;
126 }
127
128 /**
129 * GUnixInputStream:fd:
130 *
131 * The file descriptor that the stream reads from.
132 *
133 * Since: 2.20
134 */
135 g_object_class_install_property (oclass: gobject_class,
136 property_id: PROP_FD,
137 pspec: g_param_spec_int (name: "fd",
138 P_("File descriptor"),
139 P_("The file descriptor to read from"),
140 G_MININT, G_MAXINT, default_value: -1,
141 flags: G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
142
143 /**
144 * GUnixInputStream:close-fd:
145 *
146 * Whether to close the file descriptor when the stream is closed.
147 *
148 * Since: 2.20
149 */
150 g_object_class_install_property (oclass: gobject_class,
151 property_id: PROP_CLOSE_FD,
152 pspec: g_param_spec_boolean (name: "close-fd",
153 P_("Close file descriptor"),
154 P_("Whether to close the file descriptor when the stream is closed"),
155 TRUE,
156 flags: G_PARAM_READABLE | G_PARAM_WRITABLE | G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB));
157}
158
159static void
160g_unix_input_stream_pollable_iface_init (GPollableInputStreamInterface *iface)
161{
162 iface->can_poll = g_unix_input_stream_pollable_can_poll;
163 iface->is_readable = g_unix_input_stream_pollable_is_readable;
164 iface->create_source = g_unix_input_stream_pollable_create_source;
165}
166
167static void
168g_unix_input_stream_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
169{
170 iface->get_fd = (int (*) (GFileDescriptorBased *))g_unix_input_stream_get_fd;
171}
172
173static void
174g_unix_input_stream_set_property (GObject *object,
175 guint prop_id,
176 const GValue *value,
177 GParamSpec *pspec)
178{
179 GUnixInputStream *unix_stream;
180
181 unix_stream = G_UNIX_INPUT_STREAM (object);
182
183 switch (prop_id)
184 {
185 case PROP_FD:
186 unix_stream->priv->fd = g_value_get_int (value);
187 unix_stream->priv->can_poll = _g_fd_is_pollable (fd: unix_stream->priv->fd);
188 break;
189 case PROP_CLOSE_FD:
190 unix_stream->priv->close_fd = g_value_get_boolean (value);
191 break;
192 default:
193 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
194 break;
195 }
196}
197
198static void
199g_unix_input_stream_get_property (GObject *object,
200 guint prop_id,
201 GValue *value,
202 GParamSpec *pspec)
203{
204 GUnixInputStream *unix_stream;
205
206 unix_stream = G_UNIX_INPUT_STREAM (object);
207
208 switch (prop_id)
209 {
210 case PROP_FD:
211 g_value_set_int (value, v_int: unix_stream->priv->fd);
212 break;
213 case PROP_CLOSE_FD:
214 g_value_set_boolean (value, v_boolean: unix_stream->priv->close_fd);
215 break;
216 default:
217 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
218 }
219}
220
221static void
222g_unix_input_stream_init (GUnixInputStream *unix_stream)
223{
224 unix_stream->priv = g_unix_input_stream_get_instance_private (self: unix_stream);
225 unix_stream->priv->fd = -1;
226 unix_stream->priv->close_fd = TRUE;
227}
228
229/**
230 * g_unix_input_stream_new:
231 * @fd: a UNIX file descriptor
232 * @close_fd: %TRUE to close the file descriptor when done
233 *
234 * Creates a new #GUnixInputStream for the given @fd.
235 *
236 * If @close_fd is %TRUE, the file descriptor will be closed
237 * when the stream is closed.
238 *
239 * Returns: a new #GUnixInputStream
240 **/
241GInputStream *
242g_unix_input_stream_new (gint fd,
243 gboolean close_fd)
244{
245 GUnixInputStream *stream;
246
247 g_return_val_if_fail (fd != -1, NULL);
248
249 stream = g_object_new (G_TYPE_UNIX_INPUT_STREAM,
250 first_property_name: "fd", fd,
251 "close-fd", close_fd,
252 NULL);
253
254 return G_INPUT_STREAM (stream);
255}
256
257/**
258 * g_unix_input_stream_set_close_fd:
259 * @stream: a #GUnixInputStream
260 * @close_fd: %TRUE to close the file descriptor when done
261 *
262 * Sets whether the file descriptor of @stream shall be closed
263 * when the stream is closed.
264 *
265 * Since: 2.20
266 */
267void
268g_unix_input_stream_set_close_fd (GUnixInputStream *stream,
269 gboolean close_fd)
270{
271 g_return_if_fail (G_IS_UNIX_INPUT_STREAM (stream));
272
273 close_fd = close_fd != FALSE;
274 if (stream->priv->close_fd != close_fd)
275 {
276 stream->priv->close_fd = close_fd;
277 g_object_notify (G_OBJECT (stream), property_name: "close-fd");
278 }
279}
280
281/**
282 * g_unix_input_stream_get_close_fd:
283 * @stream: a #GUnixInputStream
284 *
285 * Returns whether the file descriptor of @stream will be
286 * closed when the stream is closed.
287 *
288 * Returns: %TRUE if the file descriptor is closed when done
289 *
290 * Since: 2.20
291 */
292gboolean
293g_unix_input_stream_get_close_fd (GUnixInputStream *stream)
294{
295 g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), FALSE);
296
297 return stream->priv->close_fd;
298}
299
300/**
301 * g_unix_input_stream_get_fd:
302 * @stream: a #GUnixInputStream
303 *
304 * Return the UNIX file descriptor that the stream reads from.
305 *
306 * Returns: The file descriptor of @stream
307 *
308 * Since: 2.20
309 */
310gint
311g_unix_input_stream_get_fd (GUnixInputStream *stream)
312{
313 g_return_val_if_fail (G_IS_UNIX_INPUT_STREAM (stream), -1);
314
315 return stream->priv->fd;
316}
317
318static gssize
319g_unix_input_stream_read (GInputStream *stream,
320 void *buffer,
321 gsize count,
322 GCancellable *cancellable,
323 GError **error)
324{
325 GUnixInputStream *unix_stream;
326 gssize res = -1;
327 GPollFD poll_fds[2];
328 int nfds;
329 int poll_ret;
330
331 unix_stream = G_UNIX_INPUT_STREAM (stream);
332
333 poll_fds[0].fd = unix_stream->priv->fd;
334 poll_fds[0].events = G_IO_IN;
335 if (unix_stream->priv->can_poll &&
336 g_cancellable_make_pollfd (cancellable, pollfd: &poll_fds[1]))
337 nfds = 2;
338 else
339 nfds = 1;
340
341 while (1)
342 {
343 int errsv;
344
345 poll_fds[0].revents = poll_fds[1].revents = 0;
346 do
347 {
348 poll_ret = g_poll (fds: poll_fds, nfds, timeout: -1);
349 errsv = errno;
350 }
351 while (poll_ret == -1 && errsv == EINTR);
352
353 if (poll_ret == -1)
354 {
355 g_set_error (err: error, G_IO_ERROR,
356 code: g_io_error_from_errno (err_no: errsv),
357 _("Error reading from file descriptor: %s"),
358 g_strerror (errnum: errsv));
359 break;
360 }
361
362 if (g_cancellable_set_error_if_cancelled (cancellable, error))
363 break;
364
365 if (!poll_fds[0].revents)
366 continue;
367
368 res = read (fd: unix_stream->priv->fd, buf: buffer, nbytes: count);
369 if (res == -1)
370 {
371 int errsv = errno;
372
373 if (errsv == EINTR || errsv == EAGAIN)
374 continue;
375
376 g_set_error (err: error, G_IO_ERROR,
377 code: g_io_error_from_errno (err_no: errsv),
378 _("Error reading from file descriptor: %s"),
379 g_strerror (errnum: errsv));
380 }
381
382 break;
383 }
384
385 if (nfds == 2)
386 g_cancellable_release_fd (cancellable);
387 return res;
388}
389
390static gboolean
391g_unix_input_stream_close (GInputStream *stream,
392 GCancellable *cancellable,
393 GError **error)
394{
395 GUnixInputStream *unix_stream;
396 int res;
397
398 unix_stream = G_UNIX_INPUT_STREAM (stream);
399
400 if (!unix_stream->priv->close_fd)
401 return TRUE;
402
403 /* This might block during the close. Doesn't seem to be a way to avoid it though. */
404 res = close (fd: unix_stream->priv->fd);
405 if (res == -1)
406 {
407 int errsv = errno;
408
409 g_set_error (err: error, G_IO_ERROR,
410 code: g_io_error_from_errno (err_no: errsv),
411 _("Error closing file descriptor: %s"),
412 g_strerror (errnum: errsv));
413 }
414
415 return res != -1;
416}
417
418static void
419g_unix_input_stream_skip_async (GInputStream *stream,
420 gsize count,
421 int io_priority,
422 GCancellable *cancellable,
423 GAsyncReadyCallback callback,
424 gpointer data)
425{
426 g_warn_if_reached ();
427 /* TODO: Not implemented */
428}
429
430static gssize
431g_unix_input_stream_skip_finish (GInputStream *stream,
432 GAsyncResult *result,
433 GError **error)
434{
435 g_warn_if_reached ();
436 return 0;
437 /* TODO: Not implemented */
438}
439
440static gboolean
441g_unix_input_stream_pollable_can_poll (GPollableInputStream *stream)
442{
443 return G_UNIX_INPUT_STREAM (stream)->priv->can_poll;
444}
445
446static gboolean
447g_unix_input_stream_pollable_is_readable (GPollableInputStream *stream)
448{
449 GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
450 GPollFD poll_fd;
451 gint result;
452
453 poll_fd.fd = unix_stream->priv->fd;
454 poll_fd.events = G_IO_IN;
455 poll_fd.revents = 0;
456
457 do
458 result = g_poll (fds: &poll_fd, nfds: 1, timeout: 0);
459 while (result == -1 && errno == EINTR);
460
461 return poll_fd.revents != 0;
462}
463
464static GSource *
465g_unix_input_stream_pollable_create_source (GPollableInputStream *stream,
466 GCancellable *cancellable)
467{
468 GUnixInputStream *unix_stream = G_UNIX_INPUT_STREAM (stream);
469 GSource *inner_source, *cancellable_source, *pollable_source;
470
471 pollable_source = g_pollable_source_new (G_OBJECT (stream));
472
473 inner_source = g_unix_fd_source_new (fd: unix_stream->priv->fd, condition: G_IO_IN);
474 g_source_set_dummy_callback (source: inner_source);
475 g_source_add_child_source (source: pollable_source, child_source: inner_source);
476 g_source_unref (source: inner_source);
477
478 if (cancellable)
479 {
480 cancellable_source = g_cancellable_source_new (cancellable);
481 g_source_set_dummy_callback (source: cancellable_source);
482 g_source_add_child_source (source: pollable_source, child_source: cancellable_source);
483 g_source_unref (source: cancellable_source);
484 }
485
486 return pollable_source;
487}
488

source code of gtk/subprojects/glib/gio/gunixinputstream.c