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.
44 #include "gunixfdmessage.h"
45 #include "gunixfdlist.h"
46 #include "gnetworking.h"
51 G_DEFINE_TYPE (GUnixFDMessage, g_unix_fd_message,
52 G_TYPE_SOCKET_CONTROL_MESSAGE);
54 struct _GUnixFDMessagePrivate
60 g_unix_fd_message_get_size (GSocketControlMessage *message)
62 GUnixFDMessage *fd_message = G_UNIX_FD_MESSAGE (message);
64 return g_unix_fd_list_get_length (fd_message->priv->list) * sizeof (gint);
68 g_unix_fd_message_get_level (GSocketControlMessage *message)
74 g_unix_fd_message_get_msg_type (GSocketControlMessage *message)
79 static GSocketControlMessage *
80 g_unix_fd_message_deserialize (int level,
85 GSocketControlMessage *message;
90 if (level != SOL_SOCKET ||
96 g_warning ("Kernel returned non-integral number of fds");
101 n = size / sizeof (gint);
103 /* Note we probably handled this in gsocket.c already if we're on
104 * Linux and have MSG_CMSG_CLOEXEC, but this code remains as a fallback
105 * in case the kernel is too old for MSG_CMSG_CLOEXEC.
107 for (i = 0; i < n; i++)
110 s = fcntl (fds[i], F_SETFD, FD_CLOEXEC);
111 while (s < 0 && errno == EINTR);
115 g_warning ("Error setting close-on-exec flag on incoming fd: %s",
121 list = g_unix_fd_list_new_from_array (fds, n);
122 message = g_unix_fd_message_new_with_fd_list (list);
123 g_object_unref (list);
129 g_unix_fd_message_serialize (GSocketControlMessage *message,
132 GUnixFDMessage *fd_message = G_UNIX_FD_MESSAGE (message);
136 fds = g_unix_fd_list_peek_fds (fd_message->priv->list, &n_fds);
137 memcpy (data, fds, sizeof (gint) * n_fds);
141 g_unix_fd_message_set_property (GObject *object, guint prop_id,
142 const GValue *value, GParamSpec *pspec)
144 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
146 g_assert (message->priv->list == NULL);
147 g_assert_cmpint (prop_id, ==, 1);
149 message->priv->list = g_value_dup_object (value);
151 if (message->priv->list == NULL)
152 message->priv->list = g_unix_fd_list_new ();
156 * g_unix_fd_message_get_fd_list:
157 * @message: a #GUnixFDMessage
159 * Gets the #GUnixFDList contained in @message. This function does not
160 * return a reference to the caller, but the returned list is valid for
161 * the lifetime of @message.
163 * Returns: (transfer none): the #GUnixFDList from @message
168 g_unix_fd_message_get_fd_list (GUnixFDMessage *message)
170 return message->priv->list;
174 g_unix_fd_message_get_property (GObject *object, guint prop_id,
175 GValue *value, GParamSpec *pspec)
177 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
179 g_assert_cmpint (prop_id, ==, 1);
181 g_value_set_object (value, g_unix_fd_message_get_fd_list (message));
185 g_unix_fd_message_init (GUnixFDMessage *message)
187 message->priv = G_TYPE_INSTANCE_GET_PRIVATE (message,
188 G_TYPE_UNIX_FD_MESSAGE,
189 GUnixFDMessagePrivate);
193 g_unix_fd_message_finalize (GObject *object)
195 GUnixFDMessage *message = G_UNIX_FD_MESSAGE (object);
197 g_object_unref (message->priv->list);
199 G_OBJECT_CLASS (g_unix_fd_message_parent_class)
204 g_unix_fd_message_class_init (GUnixFDMessageClass *class)
206 GSocketControlMessageClass *scm_class = G_SOCKET_CONTROL_MESSAGE_CLASS (class);
207 GObjectClass *object_class = G_OBJECT_CLASS (class);
209 g_type_class_add_private (class, sizeof (GUnixFDMessagePrivate));
210 scm_class->get_size = g_unix_fd_message_get_size;
211 scm_class->get_level = g_unix_fd_message_get_level;
212 scm_class->get_type = g_unix_fd_message_get_msg_type;
213 scm_class->serialize = g_unix_fd_message_serialize;
214 scm_class->deserialize = g_unix_fd_message_deserialize;
215 object_class->finalize = g_unix_fd_message_finalize;
216 object_class->set_property = g_unix_fd_message_set_property;
217 object_class->get_property = g_unix_fd_message_get_property;
219 g_object_class_install_property (object_class, 1,
220 g_param_spec_object ("fd-list", "file descriptor list",
221 "The GUnixFDList object to send with the message",
222 G_TYPE_UNIX_FD_LIST, G_PARAM_STATIC_STRINGS |
223 G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
227 * g_unix_fd_message_new:
229 * Creates a new #GUnixFDMessage containing an empty file descriptor
232 * Returns: a new #GUnixFDMessage
236 GSocketControlMessage *
237 g_unix_fd_message_new (void)
239 return g_object_new (G_TYPE_UNIX_FD_MESSAGE, NULL);
243 * g_unix_fd_message_new_with_fd_list:
244 * @fd_list: a #GUnixFDList
246 * Creates a new #GUnixFDMessage containing @list.
248 * Returns: a new #GUnixFDMessage
252 GSocketControlMessage *
253 g_unix_fd_message_new_with_fd_list (GUnixFDList *fd_list)
255 return g_object_new (G_TYPE_UNIX_FD_MESSAGE,
261 * g_unix_fd_message_steal_fds:
262 * @message: a #GUnixFDMessage
263 * @length: (out) (allow-none): pointer to the length of the returned
266 * Returns the array of file descriptors that is contained in this
269 * After this call, the descriptors are no longer contained in
270 * @message. Further calls will return an empty list (unless more
271 * descriptors have been added).
273 * The return result of this function must be freed with g_free().
274 * The caller is also responsible for closing all of the file
277 * If @length is non-%NULL then it is set to the number of file
278 * descriptors in the returned array. The returned array is also
279 * terminated with -1.
281 * This function never returns %NULL. In case there are no file
282 * descriptors contained in @message, an empty array is returned.
284 * Returns: (array length=length) (transfer full): an array of file
290 g_unix_fd_message_steal_fds (GUnixFDMessage *message,
293 g_return_val_if_fail (G_UNIX_FD_MESSAGE (message), NULL);
295 return g_unix_fd_list_steal_fds (message->priv->list, length);
299 * g_unix_fd_message_append_fd:
300 * @message: a #GUnixFDMessage
301 * @fd: a valid open file descriptor
302 * @error: a #GError pointer
304 * Adds a file descriptor to @message.
306 * The file descriptor is duplicated using dup(). You keep your copy
307 * of the descriptor and the copy contained in @message will be closed
308 * when @message is finalized.
310 * A possible cause of failure is exceeding the per-process or
311 * system-wide file descriptor limit.
313 * Returns: %TRUE in case of success, else %FALSE (and @error is set)
318 g_unix_fd_message_append_fd (GUnixFDMessage *message,
322 g_return_val_if_fail (G_UNIX_FD_MESSAGE (message), FALSE);
324 return g_unix_fd_list_append (message->priv->list, fd, error) >= 0;