1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright © 2009 Codethink Limited
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License as published
7 * by the Free Software Foundation; either version 2 of the licence or (at
8 * your option) any later version.
10 * See the included COPYING file for more information.
12 * Authors: Ryan Lortie <desrt@desrt.ca>
16 * SECTION: gunixfdmessage
17 * @title: GUnixFDMessage
18 * @short_description: A GSocketControlMessage containing a GUnixFDList
19 * @include: gio/gunixfdmessage.h
20 * @see_also: #GUnixConnection, #GUnixFDList, #GSocketControlMessage
22 * This #GSocketControlMessage contains a #GUnixFDList.
23 * It may be sent using g_socket_send_message() and received using
24 * g_socket_receive_message() over UNIX sockets (ie: sockets in the
25 * %G_SOCKET_ADDRESS_UNIX family). The file descriptors are copied
26 * between processes by the kernel.
28 * For an easier way to send and receive file descriptors over
29 * stream-oriented UNIX sockets, see g_unix_connection_send_fd() and
30 * g_unix_connection_receive_fd().
32 * Note that <filename><gio/gunixfdmessage.h></filename> belongs to
33 * the UNIX-specific GIO interfaces, thus you have to use the
34 * <filename>gio-unix-2.0.pc</filename> pkg-config file when using it.
39 #include <sys/types.h>
40 #include <sys/socket.h>
46 #include "gunixfdmessage.h"
47 #include "gunixfdlist.h"
53 G_DEFINE_TYPE (GUnixFDMessage, g_unix_fd_message,
54 G_TYPE_SOCKET_CONTROL_MESSAGE);
56 struct _GUnixFDMessagePrivate
62 g_unix_fd_message_get_size (GSocketControlMessage *message)
64 GUnixFDMessage *fd_message = G_UNIX_FD_MESSAGE (message);
66 return g_unix_fd_list_get_length (fd_message->priv->list) * sizeof (gint);
70 g_unix_fd_message_get_level (GSocketControlMessage *message)
76 g_unix_fd_message_get_msg_type (GSocketControlMessage *message)
81 static GSocketControlMessage *
82 g_unix_fd_message_deserialize (int level,
87 GSocketControlMessage *message;
92 if (level != SOL_SOCKET ||
98 g_warning ("Kernel returned non-integral number of fds");
103 n = size / sizeof (gint);
105 for (i = 0; i < n; i++)
108 s = fcntl (fds[i], F_SETFD, FD_CLOEXEC);
109 while (s < 0 && errno == EINTR);
113 g_warning ("Error setting close-on-exec flag on incoming fd: %s",
119 list = g_unix_fd_list_new_from_array (fds, n);
120 message = g_unix_fd_message_new_with_fd_list (list);
121 g_object_unref (list);
127 g_unix_fd_message_serialize (GSocketControlMessage *message,
130 GUnixFDMessage *fd_message = G_UNIX_FD_MESSAGE (message);
134 fds = g_unix_fd_list_peek_fds (fd_message->priv->list, &n_fds);
135 memcpy (data, fds, sizeof (gint) * n_fds);
139 g_unix_fd_message_set_property (GObject *object, guint prop_id,
140 const GValue *value, GParamSpec *pspec)
142 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
144 g_assert (message->priv->list == NULL);
145 g_assert_cmpint (prop_id, ==, 1);
147 message->priv->list = g_value_dup_object (value);
149 if (message->priv->list == NULL)
150 message->priv->list = g_unix_fd_list_new ();
154 * g_unix_fd_message_get_fd_list:
155 * @message: a #GUnixFDMessage
157 * Gets the #GUnixFDList contained in @message. This function does not
158 * return a reference to the caller, but the returned list is valid for
159 * the lifetime of @message.
161 * Returns: the #GUnixFDList from @message
166 g_unix_fd_message_get_fd_list (GUnixFDMessage *message)
168 return message->priv->list;
172 g_unix_fd_message_get_property (GObject *object, guint prop_id,
173 GValue *value, GParamSpec *pspec)
175 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
177 g_assert_cmpint (prop_id, ==, 1);
179 g_value_set_object (value, g_unix_fd_message_get_fd_list (message));
183 g_unix_fd_message_init (GUnixFDMessage *message)
185 message->priv = G_TYPE_INSTANCE_GET_PRIVATE (message,
186 G_TYPE_UNIX_FD_MESSAGE,
187 GUnixFDMessagePrivate);
191 g_unix_fd_message_finalize (GObject *object)
193 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
195 g_object_unref (message->priv->list);
197 G_OBJECT_CLASS (g_unix_fd_message_parent_class)
202 g_unix_fd_message_class_init (GUnixFDMessageClass *class)
204 GSocketControlMessageClass *scm_class = G_SOCKET_CONTROL_MESSAGE_CLASS (class);
205 GObjectClass *object_class = G_OBJECT_CLASS (class);
207 g_type_class_add_private (class, sizeof (GUnixFDMessagePrivate));
208 scm_class->get_size = g_unix_fd_message_get_size;
209 scm_class->get_level = g_unix_fd_message_get_level;
210 scm_class->get_type = g_unix_fd_message_get_msg_type;
211 scm_class->serialize = g_unix_fd_message_serialize;
212 scm_class->deserialize = g_unix_fd_message_deserialize;
213 object_class->finalize = g_unix_fd_message_finalize;
214 object_class->set_property = g_unix_fd_message_set_property;
215 object_class->get_property = g_unix_fd_message_get_property;
217 g_object_class_install_property (object_class, 1,
218 g_param_spec_object ("fd-list", "file descriptor list",
219 "The GUnixFDList object to send with the message",
220 G_TYPE_UNIX_FD_LIST, G_PARAM_STATIC_STRINGS |
221 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
225 * g_unix_fd_message_new:
227 * Creates a new #GUnixFDMessage containing an empty file descriptor
230 * Returns: a new #GUnixFDMessage
234 GSocketControlMessage *
235 g_unix_fd_message_new (void)
237 return g_object_new (G_TYPE_UNIX_FD_MESSAGE, NULL);
241 * g_unix_fd_message_new_with_fd_list:
242 * @fd_list: a #GUnixFDList
244 * Creates a new #GUnixFDMessage containing @list.
246 * Returns: a new #GUnixFDMessage
250 GSocketControlMessage *
251 g_unix_fd_message_new_with_fd_list (GUnixFDList *fd_list)
253 return g_object_new (G_TYPE_UNIX_FD_MESSAGE,
259 * g_unix_fd_message_steal_fds:
260 * @message: a #GUnixFDMessage
261 * @length: pointer to the length of the returned array, or %NULL
263 * Returns the array of file descriptors that is contained in this
266 * After this call, the descriptors are no longer contained in
267 * @message. Further calls will return an empty list (unless more
268 * descriptors have been added).
270 * The return result of this function must be freed with g_free().
271 * The caller is also responsible for closing all of the file
274 * If @length is non-%NULL then it is set to the number of file
275 * descriptors in the returned array. The returned array is also
276 * terminated with -1.
278 * This function never returns %NULL. In case there are no file
279 * descriptors contained in @message, an empty array is returned.
281 * Returns: an array of file descriptors
286 g_unix_fd_message_steal_fds (GUnixFDMessage *message,
289 g_return_val_if_fail (G_UNIX_FD_MESSAGE (message), FALSE);
291 return g_unix_fd_list_steal_fds (message->priv->list, length);
295 * g_unix_fd_message_append_fd:
296 * @message: a #GUnixFDMessage
297 * @fd: a valid open file descriptor
298 * @error: a #GError pointer
300 * Adds a file descriptor to @message.
302 * The file descriptor is duplicated using dup(). You keep your copy
303 * of the descriptor and the copy contained in @message will be closed
304 * when @message is finalized.
306 * A possible cause of failure is exceeding the per-process or
307 * system-wide file descriptor limit.
309 * Returns: %TRUE in case of success, else %FALSE (and @error is set)
314 g_unix_fd_message_append_fd (GUnixFDMessage *message,
318 g_return_val_if_fail (G_UNIX_FD_MESSAGE (message), FALSE);
320 return g_unix_fd_list_append (message->priv->list, fd, error) > 0;
323 #define __G_UNIX_FD_MESSAGE_C__
324 #include "gioaliasdef.c"