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fuchsia / third_party / glib / 7c909697db0f636692edc60954694187ffbd7260 / . / gio / gsocket.c
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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2008 Christian Kellner, Samuel Cormier-Iijima
* Copyright © 2009 Codethink Limited
* Copyright © 2009 Red Hat, Inc
* Copyright © 2015 Collabora, Ltd.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Authors: Christian Kellner <gicmo@gnome.org>
* Samuel Cormier-Iijima <sciyoshi@gmail.com>
* Ryan Lortie <desrt@desrt.ca>
* Alexander Larsson <alexl@redhat.com>
* Philip Withnall <philip.withnall@collabora.co.uk>
*/
#include "config.h"
#include "gsocket.h"
#ifdef G_OS_UNIX
#include "glib-unix.h"
#endif
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#ifndef G_OS_WIN32
# include <fcntl.h>
# include <unistd.h>
# include <sys/ioctl.h>
#endif
#ifdef HAVE_SIOCGIFADDR
#include <net/if.h>
#endif
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif
#ifdef G_OS_UNIX
#include <sys/uio.h>
#endif
#define GOBJECT_COMPILATION
#include "gobject/gtype-private.h" /* For _PRELUDE type define */
#undef GOBJECT_COMPILATION
#include "gcancellable.h"
#include "gdatagrambased.h"
#include "gioenumtypes.h"
#include "ginetaddress.h"
#include "ginetsocketaddress.h"
#include "ginitable.h"
#include "gioerror.h"
#include "gioenums.h"
#include "gioerror.h"
#include "gnetworkingprivate.h"
#include "gsocketaddress.h"
#include "gsocketcontrolmessage.h"
#include "gcredentials.h"
#include "gcredentialsprivate.h"
#include "glibintl.h"
#include "gioprivate.h"
#ifdef G_OS_WIN32
#include "giowin32-afunix.h"
#endif
/**
* GSocket:
*
* A `GSocket` is a low-level networking primitive. It is a more or less
* direct mapping of the BSD socket API in a portable GObject based API.
* It supports both the UNIX socket implementations and winsock2 on Windows.
*
* `GSocket` is the platform independent base upon which the higher level
* network primitives are based. Applications are not typically meant to
* use it directly, but rather through classes like [class@Gio.SocketClient],
* [class@Gio.SocketService] and [class@Gio.SocketConnection]. However there may
* be cases where direct use of `GSocket` is useful.
*
* `GSocket` implements the [iface@Gio.Initable] interface, so if it is manually
* constructed by e.g. [ctor@GObject.Object.new] you must call
* [method@Gio.Initable.init] and check the results before using the object.
* This is done automatically in [ctor@Gio.Socket.new] and
* [ctor@Gio.Socket.new_from_fd], so these functions can return `NULL`.
*
* Sockets operate in two general modes, blocking or non-blocking. When
* in blocking mode all operations (which don’t take an explicit blocking
* parameter) block until the requested operation
* is finished or there is an error. In non-blocking mode all calls that
* would block return immediately with a `G_IO_ERROR_WOULD_BLOCK` error.
* To know when a call would successfully run you can call
* [method@Gio.Socket.condition_check], or [method@Gio.Socket.condition_wait].
* You can also use [method@Gio.Socket.create_source] and attach it to a
* [type@GLib.MainContext] to get callbacks when I/O is possible.
* Note that all sockets are always set to non blocking mode in the system, and
* blocking mode is emulated in `GSocket`.
*
* When working in non-blocking mode applications should always be able to
* handle getting a `G_IO_ERROR_WOULD_BLOCK` error even when some other
* function said that I/O was possible. This can easily happen in case
* of a race condition in the application, but it can also happen for other
* reasons. For instance, on Windows a socket is always seen as writable
* until a write returns `G_IO_ERROR_WOULD_BLOCK`.
*
* `GSocket`s can be either connection oriented or datagram based.
* For connection oriented types you must first establish a connection by
* either connecting to an address or accepting a connection from another
* address. For connectionless socket types the target/source address is
* specified or received in each I/O operation.
*
* All socket file descriptors are set to be close-on-exec.
*
* Note that creating a `GSocket` causes the signal `SIGPIPE` to be
* ignored for the remainder of the program. If you are writing a
* command-line utility that uses `GSocket`, you may need to take into
* account the fact that your program will not automatically be killed
* if it tries to write to `stdout` after it has been closed.
*
* Like most other APIs in GLib, `GSocket` is not inherently thread safe. To use
* a `GSocket` concurrently from multiple threads, you must implement your own
* locking.
*
* ## Nagle’s algorithm
*
* Since GLib 2.80, `GSocket` will automatically set the `TCP_NODELAY` option on
* all `G_SOCKET_TYPE_STREAM` sockets. This disables
* [Nagle’s algorithm](https://en.wikipedia.org/wiki/Nagle%27s_algorithm) as it
* typically does more harm than good on modern networks.
*
* If your application needs Nagle’s algorithm enabled, call
* [method@Gio.Socket.set_option] after constructing a `GSocket` to enable it:
* ```c
* socket = g_socket_new (…, G_SOCKET_TYPE_STREAM, …);
* if (socket != NULL)
* {
* g_socket_set_option (socket, IPPROTO_TCP, TCP_NODELAY, FALSE, &local_error);
* // handle error if needed
* }
* ```
*
* Since: 2.22
*/
static void g_socket_initable_iface_init (GInitableIface *iface);
static gboolean g_socket_initable_init (GInitable *initable,
GCancellable *cancellable,
GError **error);
static void g_socket_datagram_based_iface_init (GDatagramBasedInterface *iface);
static gint g_socket_datagram_based_receive_messages (GDatagramBased *self,
GInputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
static gint g_socket_datagram_based_send_messages (GDatagramBased *self,
GOutputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
static GSource *g_socket_datagram_based_create_source (GDatagramBased *self,
GIOCondition condition,
GCancellable *cancellable);
static GIOCondition g_socket_datagram_based_condition_check (GDatagramBased *datagram_based,
GIOCondition condition);
static gboolean g_socket_datagram_based_condition_wait (GDatagramBased *datagram_based,
GIOCondition condition,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
static GSocketAddress *
cache_recv_address (GSocket *socket, struct sockaddr *native, size_t native_len);
static gssize
g_socket_receive_message_with_timeout (GSocket *socket,
GSocketAddress **address,
GInputVector *vectors,
gint num_vectors,
GSocketControlMessage ***messages,
gint *num_messages,
gint *flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
static gint
g_socket_receive_messages_with_timeout (GSocket *socket,
GInputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
static gint
g_socket_send_messages_with_timeout (GSocket *socket,
GOutputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error);
enum
{
PROP_0,
PROP_FAMILY,
PROP_TYPE,
PROP_PROTOCOL,
PROP_FD,
PROP_BLOCKING,
PROP_LISTEN_BACKLOG,
PROP_KEEPALIVE,
PROP_LOCAL_ADDRESS,
PROP_REMOTE_ADDRESS,
PROP_TIMEOUT,
PROP_TTL,
PROP_BROADCAST,
PROP_MULTICAST_LOOPBACK,
PROP_MULTICAST_TTL
};
/* Size of the receiver cache for g_socket_receive_from() */
#define RECV_ADDR_CACHE_SIZE 8
struct _GSocketPrivate
{
GSocketFamily family;
GSocketType type;
GSocketProtocol protocol;
gint fd;
gint listen_backlog;
guint timeout;
GError *construct_error;
GSocketAddress *remote_address;
guint inited : 1;
guint blocking : 1;
guint keepalive : 1;
guint closed : 1;
guint connected_read : 1;
guint connected_write : 1;
guint listening : 1;
guint timed_out : 1;
guint connect_pending : 1;
#ifdef G_OS_WIN32
WSAEVENT event;
gboolean waiting;
DWORD waiting_result;
int current_events;
int current_errors;
int selected_events;
GList *requested_conditions; /* list of requested GIOCondition * */
GMutex win32_source_lock;
GCond win32_source_cond;
#endif
struct {
GSocketAddress *addr;
struct sockaddr *native;
gsize native_len;
guint64 last_used;
} recv_addr_cache[RECV_ADDR_CACHE_SIZE];
};
_G_DEFINE_TYPE_EXTENDED_WITH_PRELUDE (GSocket, g_socket, G_TYPE_OBJECT, 0,
/* Need a prelude for https://bugzilla.gnome.org/show_bug.cgi?id=674885 */
g_type_ensure (G_TYPE_SOCKET_FAMILY);
g_type_ensure (G_TYPE_SOCKET_TYPE);
g_type_ensure (G_TYPE_SOCKET_PROTOCOL);
g_type_ensure (G_TYPE_SOCKET_ADDRESS);
/* And networking init is appropriate for the prelude */
g_networking_init ();
, /* And now the regular type init code */
G_ADD_PRIVATE (GSocket)
G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
g_socket_initable_iface_init);
G_IMPLEMENT_INTERFACE (G_TYPE_DATAGRAM_BASED,
g_socket_datagram_based_iface_init));
static int
get_socket_errno (void)
{
#ifndef G_OS_WIN32
return errno;
#else
return WSAGetLastError ();
#endif
}
static GIOErrorEnum
socket_io_error_from_errno (int err)
{
#ifdef G_OS_WIN32
return g_io_error_from_win32_error (err);
#else
return g_io_error_from_errno (err);
#endif
}
static const char *
socket_strerror (int err)
{
#ifndef G_OS_WIN32
return g_strerror (err);
#else
const char *msg_ret;
char *msg;
msg = g_win32_error_message (err);
msg_ret = g_intern_string (msg);
g_free (msg);
return msg_ret;
#endif
}
/* Wrapper around g_set_error() to avoid doing excess work */
#define socket_set_error_lazy(err, errsv, fmt) \
G_STMT_START { \
GError **__err = (err); \
int __errsv = (errsv); \
\
if (__err) \
{ \
int __code = socket_io_error_from_errno (__errsv); \
const char *__strerr = socket_strerror (__errsv); \
\
if (__code == G_IO_ERROR_WOULD_BLOCK) \
g_set_error_literal (__err, G_IO_ERROR, __code, __strerr); \
else \
g_set_error (__err, G_IO_ERROR, __code, fmt, __strerr); \
} \
} G_STMT_END
#ifdef G_OS_WIN32
#define win32_unset_event_mask(_socket, _mask) _win32_unset_event_mask (_socket, _mask)
static void
_win32_unset_event_mask (GSocket *socket, int mask)
{
g_mutex_lock (&socket->priv->win32_source_lock);
socket->priv->current_events &= ~mask;
socket->priv->current_errors &= ~mask;
g_mutex_unlock (&socket->priv->win32_source_lock);
}
#else
#define win32_unset_event_mask(_socket, _mask)
#endif
/* Windows has broken prototypes... */
#ifdef G_OS_WIN32
#define getsockopt(sockfd, level, optname, optval, optlen) \
getsockopt (sockfd, level, optname, (gpointer) optval, (int*) optlen)
#define setsockopt(sockfd, level, optname, optval, optlen) \
setsockopt (sockfd, level, optname, (gpointer) optval, optlen)
#define getsockname(sockfd, addr, addrlen) \
getsockname (sockfd, addr, (int *)addrlen)
#define getpeername(sockfd, addr, addrlen) \
getpeername (sockfd, addr, (int *)addrlen)
#define recv(sockfd, buf, len, flags) \
recv (sockfd, (gpointer)buf, len, flags)
#endif
static gchar *
address_to_string (GSocketAddress *address)
{
GString *ret = g_string_new ("");
if (G_IS_INET_SOCKET_ADDRESS (address))
{
GInetSocketAddress *isa = G_INET_SOCKET_ADDRESS (address);
GInetAddress *ia = g_inet_socket_address_get_address (isa);
GSocketFamily family = g_inet_address_get_family (ia);
gchar *tmp;
/* Represent IPv6 addresses in URL style:
* ::1 port 12345 -> [::1]:12345 */
if (family == G_SOCKET_FAMILY_IPV6)
g_string_append_c (ret, '[');
tmp = g_inet_address_to_string (ia);
g_string_append (ret, tmp);
g_free (tmp);
if (family == G_SOCKET_FAMILY_IPV6)
{
guint32 scope = g_inet_socket_address_get_scope_id (isa);
if (scope != 0)
g_string_append_printf (ret, "%%%u", scope);
g_string_append_c (ret, ']');
}
g_string_append_c (ret, ':');
g_string_append_printf (ret, "%u", g_inet_socket_address_get_port (isa));
}
else
{
/* For unknown address types, just show the type */
g_string_append_printf (ret, "(%s)", G_OBJECT_TYPE_NAME (address));
}
return g_string_free (ret, FALSE);
}
static gboolean
check_socket (GSocket *socket,
GError **error)
{
if (!socket->priv->inited)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_INITIALIZED,
_("Invalid socket, not initialized"));
return FALSE;
}
if (socket->priv->construct_error)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_INITIALIZED,
_("Invalid socket, initialization failed due to: %s"),
socket->priv->construct_error->message);
return FALSE;
}
if (socket->priv->closed)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
_("Socket is already closed"));
return FALSE;
}
return TRUE;
}
static gboolean
check_timeout (GSocket *socket,
GError **error)
{
if (socket->priv->timed_out)
{
socket->priv->timed_out = FALSE;
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_TIMED_OUT,
_("Socket I/O timed out"));
return FALSE;
}
return TRUE;
}
static void
g_socket_details_from_fd (GSocket *socket)
{
union {
struct sockaddr_storage storage;
struct sockaddr sa;
} address;
gint fd;
socklen_t addrlen;
int value, family;
int errsv;
memset (&address, 0, sizeof (address));
fd = socket->priv->fd;
if (!g_socket_get_option (socket, SOL_SOCKET, SO_TYPE, &value, NULL))
{
errsv = get_socket_errno ();
goto err;
}
switch (value)
{
case SOCK_STREAM:
socket->priv->type = G_SOCKET_TYPE_STREAM;
break;
case SOCK_DGRAM:
socket->priv->type = G_SOCKET_TYPE_DATAGRAM;
break;
case SOCK_SEQPACKET:
socket->priv->type = G_SOCKET_TYPE_SEQPACKET;
break;
default:
socket->priv->type = G_SOCKET_TYPE_INVALID;
break;
}
addrlen = sizeof address;
if (getsockname (fd, &address.sa, &addrlen) != 0)
{
errsv = get_socket_errno ();
goto err;
}
if (addrlen > 0)
{
g_assert (G_STRUCT_OFFSET (struct sockaddr, sa_family) +
(socklen_t) sizeof address.storage.ss_family <= addrlen);
family = address.storage.ss_family;
}
else
{
/* On Solaris, this happens if the socket is not yet connected.
* But we can use SO_DOMAIN as a workaround there.
*/
#ifdef SO_DOMAIN
if (!g_socket_get_option (socket, SOL_SOCKET, SO_DOMAIN, &family, NULL))
{
errsv = get_socket_errno ();
goto err;
}
#else
/* This will translate to G_IO_ERROR_FAILED on either unix or windows */
errsv = -1;
goto err;
#endif
}
switch (family)
{
case G_SOCKET_FAMILY_IPV4:
case G_SOCKET_FAMILY_IPV6:
socket->priv->family = address.storage.ss_family;
switch (socket->priv->type)
{
case G_SOCKET_TYPE_STREAM:
socket->priv->protocol = G_SOCKET_PROTOCOL_TCP;
break;
case G_SOCKET_TYPE_DATAGRAM:
socket->priv->protocol = G_SOCKET_PROTOCOL_UDP;
break;
case G_SOCKET_TYPE_SEQPACKET:
socket->priv->protocol = G_SOCKET_PROTOCOL_SCTP;
break;
default:
break;
}
break;
case G_SOCKET_FAMILY_UNIX:
socket->priv->family = G_SOCKET_FAMILY_UNIX;
socket->priv->protocol = G_SOCKET_PROTOCOL_DEFAULT;
break;
default:
socket->priv->family = G_SOCKET_FAMILY_INVALID;
break;
}
if (socket->priv->family != G_SOCKET_FAMILY_INVALID)
{
addrlen = sizeof address;
if (getpeername (fd, &address.sa, &addrlen) >= 0)
{
socket->priv->connected_read = TRUE;
socket->priv->connected_write = TRUE;
}
}
if (g_socket_get_option (socket, SOL_SOCKET, SO_KEEPALIVE, &value, NULL))
{
socket->priv->keepalive = !!value;
}
else
{
/* Can't read, maybe not supported, assume FALSE */
socket->priv->keepalive = FALSE;
}
return;
err:
g_set_error (&socket->priv->construct_error, G_IO_ERROR,
socket_io_error_from_errno (errsv),
_("creating GSocket from fd: %s"),
socket_strerror (errsv));
}
static void
socket_set_nonblock (int fd)
{
#ifndef G_OS_WIN32
GError *error = NULL;
#else
gulong arg;
#endif
/* Always use native nonblocking sockets, as Windows sets sockets to
* nonblocking automatically in certain operations. This way we make
* things work the same on all platforms.
*/
#ifndef G_OS_WIN32
if (!g_unix_set_fd_nonblocking (fd, TRUE, &error))
{
g_warning ("Error setting socket to nonblocking mode: %s", error->message);
g_clear_error (&error);
}
#else
arg = TRUE;
if (ioctlsocket (fd, FIONBIO, &arg) == SOCKET_ERROR)
{
int errsv = get_socket_errno ();
g_warning ("Error setting socket status flags: %s", socket_strerror (errsv));
}
#endif
}
/* Wrapper around socket() that is shared with gnetworkmonitornetlink.c.
* It always sets SOCK_CLOEXEC | SOCK_NONBLOCK. */
gint
g_socket (gint domain,
gint type,
gint protocol,
GError **error)
{
int fd, errsv;
#if defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
fd = socket (domain, type | SOCK_CLOEXEC | SOCK_NONBLOCK, protocol);
errsv = errno;
if (fd != -1)
return fd;
/* It's possible that libc has SOCK_CLOEXEC and/or SOCK_NONBLOCK but the kernel does not */
if (fd < 0 && (errsv == EINVAL || errsv == EPROTOTYPE))
#endif
fd = socket (domain, type, protocol);
if (fd < 0)
{
errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
_("Unable to create socket: %s"), socket_strerror (errsv));
errno = errsv;
return -1;
}
#ifndef G_OS_WIN32
{
int flags;
/* We always want to set close-on-exec to protect users. If you
need to so some weird inheritance to exec you can re-enable this
using lower level hacks with g_socket_get_fd(). */
flags = fcntl (fd, F_GETFD, 0);
if (flags != -1 &&
(flags & FD_CLOEXEC) == 0)
{
flags |= FD_CLOEXEC;
(void) fcntl (fd, F_SETFD, flags);
}
}
#else
if ((domain == AF_INET || domain == AF_INET6) && type == SOCK_DGRAM)
{
BOOL new_behavior = FALSE;
DWORD bytes_returned = 0;
/* Disable connection reset error on ICMP port unreachable. */
WSAIoctl (fd, SIO_UDP_CONNRESET, &new_behavior, sizeof (new_behavior),
NULL, 0, &bytes_returned, NULL, NULL);
}
#endif
/* Ensure the socket is non-blocking. */
socket_set_nonblock (fd);
return fd;
}
/* Returned socket has SOCK_CLOEXEC | SOCK_NONBLOCK set. */
static gint
g_socket_create_socket (GSocketFamily family,
GSocketType type,
int protocol,
GError **error)
{
gint native_type;
switch (type)
{
case G_SOCKET_TYPE_STREAM:
native_type = SOCK_STREAM;
break;
case G_SOCKET_TYPE_DATAGRAM:
native_type = SOCK_DGRAM;
break;
case G_SOCKET_TYPE_SEQPACKET:
native_type = SOCK_SEQPACKET;
break;
default:
g_assert_not_reached ();
}
if (family <= 0)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
_("Unable to create socket: %s"), _("Unknown family was specified"));
return -1;
}
if (protocol == -1)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
_("Unable to create socket: %s"), _("Unknown protocol was specified"));
return -1;
}
return g_socket (family, native_type, protocol, error);
}
static void
g_socket_constructed (GObject *object)
{
GSocket *socket = G_SOCKET (object);
if (socket->priv->fd >= 0)
{
/* create socket->priv info from the fd and ensure it’s non-blocking */
g_socket_details_from_fd (socket);
socket_set_nonblock (socket->priv->fd);
}
else
{
/* create the fd from socket->priv info; this sets it non-blocking by construction */
socket->priv->fd = g_socket_create_socket (socket->priv->family,
socket->priv->type,
socket->priv->protocol,
&socket->priv->construct_error);
}
if (socket->priv->fd != -1)
{
#ifdef SO_NOSIGPIPE
/* See note about SIGPIPE below. */
g_socket_set_option (socket, SOL_SOCKET, SO_NOSIGPIPE, TRUE, NULL);
#endif
if (socket->priv->type == G_SOCKET_TYPE_STREAM)
g_socket_set_option (socket, IPPROTO_TCP, TCP_NODELAY, TRUE, NULL);
}
}
static void
g_socket_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GSocket *socket = G_SOCKET (object);
GSocketAddress *address;
switch (prop_id)
{
case PROP_FAMILY:
g_value_set_enum (value, socket->priv->family);
break;
case PROP_TYPE:
g_value_set_enum (value, socket->priv->type);
break;
case PROP_PROTOCOL:
g_value_set_enum (value, socket->priv->protocol);
break;
case PROP_FD:
g_value_set_int (value, socket->priv->fd);
break;
case PROP_BLOCKING:
g_value_set_boolean (value, socket->priv->blocking);
break;
case PROP_LISTEN_BACKLOG:
g_value_set_int (value, socket->priv->listen_backlog);
break;
case PROP_KEEPALIVE:
g_value_set_boolean (value, socket->priv->keepalive);
break;
case PROP_LOCAL_ADDRESS:
address = g_socket_get_local_address (socket, NULL);
g_value_take_object (value, address);
break;
case PROP_REMOTE_ADDRESS:
address = g_socket_get_remote_address (socket, NULL);
g_value_take_object (value, address);
break;
case PROP_TIMEOUT:
g_value_set_uint (value, socket->priv->timeout);
break;
case PROP_TTL:
g_value_set_uint (value, g_socket_get_ttl (socket));
break;
case PROP_BROADCAST:
g_value_set_boolean (value, g_socket_get_broadcast (socket));
break;
case PROP_MULTICAST_LOOPBACK:
g_value_set_boolean (value, g_socket_get_multicast_loopback (socket));
break;
case PROP_MULTICAST_TTL:
g_value_set_uint (value, g_socket_get_multicast_ttl (socket));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
g_socket_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GSocket *socket = G_SOCKET (object);
switch (prop_id)
{
case PROP_FAMILY:
socket->priv->family = g_value_get_enum (value);
break;
case PROP_TYPE:
socket->priv->type = g_value_get_enum (value);
break;
case PROP_PROTOCOL:
socket->priv->protocol = g_value_get_enum (value);
break;
case PROP_FD:
socket->priv->fd = g_value_get_int (value);
break;
case PROP_BLOCKING:
g_socket_set_blocking (socket, g_value_get_boolean (value));
break;
case PROP_LISTEN_BACKLOG:
g_socket_set_listen_backlog (socket, g_value_get_int (value));
break;
case PROP_KEEPALIVE:
g_socket_set_keepalive (socket, g_value_get_boolean (value));
break;
case PROP_TIMEOUT:
g_socket_set_timeout (socket, g_value_get_uint (value));
break;
case PROP_TTL:
g_socket_set_ttl (socket, g_value_get_uint (value));
break;
case PROP_BROADCAST:
g_socket_set_broadcast (socket, g_value_get_boolean (value));
break;
case PROP_MULTICAST_LOOPBACK:
g_socket_set_multicast_loopback (socket, g_value_get_boolean (value));
break;
case PROP_MULTICAST_TTL:
g_socket_set_multicast_ttl (socket, g_value_get_uint (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
g_socket_finalize (GObject *object)
{
GSocket *socket = G_SOCKET (object);
gint i;
g_clear_error (&socket->priv->construct_error);
if (socket->priv->fd != -1 &&
!socket->priv->closed)
g_socket_close (socket, NULL);
if (socket->priv->remote_address)
g_object_unref (socket->priv->remote_address);
#ifdef G_OS_WIN32
if (socket->priv->event != WSA_INVALID_EVENT)
{
WSACloseEvent (socket->priv->event);
socket->priv->event = WSA_INVALID_EVENT;
}
g_assert (socket->priv->requested_conditions == NULL);
g_mutex_clear (&socket->priv->win32_source_lock);
g_cond_clear (&socket->priv->win32_source_cond);
#endif
for (i = 0; i < RECV_ADDR_CACHE_SIZE; i++)
{
if (socket->priv->recv_addr_cache[i].addr)
{
g_object_unref (socket->priv->recv_addr_cache[i].addr);
g_free (socket->priv->recv_addr_cache[i].native);
}
}
if (G_OBJECT_CLASS (g_socket_parent_class)->finalize)
(*G_OBJECT_CLASS (g_socket_parent_class)->finalize) (object);
}
static void
g_socket_class_init (GSocketClass *klass)
{
GObjectClass *gobject_class G_GNUC_UNUSED = G_OBJECT_CLASS (klass);
#ifdef SIGPIPE
/* There is no portable, thread-safe way to avoid having the process
* be killed by SIGPIPE when calling send() or sendmsg(), so we are
* forced to simply ignore the signal process-wide.
*
* Even if we ignore it though, gdb will still stop if the app
* receives a SIGPIPE, which can be confusing and annoying. So when
* possible, we also use MSG_NOSIGNAL / SO_NOSIGPIPE elsewhere to
* prevent the signal from occurring at all.
*/
signal (SIGPIPE, SIG_IGN);
#endif
gobject_class->finalize = g_socket_finalize;
gobject_class->constructed = g_socket_constructed;
gobject_class->set_property = g_socket_set_property;
gobject_class->get_property = g_socket_get_property;
/**
* GSocket:family:
*
* The socket’s address family.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_FAMILY,
g_param_spec_enum ("family", NULL, NULL,
G_TYPE_SOCKET_FAMILY,
G_SOCKET_FAMILY_INVALID,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:type:
*
* The socket’s type.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_TYPE,
g_param_spec_enum ("type", NULL, NULL,
G_TYPE_SOCKET_TYPE,
G_SOCKET_TYPE_STREAM,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:protocol:
*
* The ID of the protocol to use, or `-1` for unknown.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_PROTOCOL,
g_param_spec_enum ("protocol", NULL, NULL,
G_TYPE_SOCKET_PROTOCOL,
G_SOCKET_PROTOCOL_UNKNOWN,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:fd:
*
* The socket’s file descriptor.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_FD,
g_param_spec_int ("fd", NULL, NULL,
G_MININT,
G_MAXINT,
-1,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:blocking:
*
* Whether I/O on this socket is blocking.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_BLOCKING,
g_param_spec_boolean ("blocking", NULL, NULL,
TRUE,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:listen-backlog:
*
* The number of outstanding connections in the listen queue.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_LISTEN_BACKLOG,
g_param_spec_int ("listen-backlog", NULL, NULL,
0,
SOMAXCONN,
10,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:keepalive:
*
* Whether to keep the connection alive by sending periodic pings.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_KEEPALIVE,
g_param_spec_boolean ("keepalive", NULL, NULL,
FALSE,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:local-address:
*
* The local address the socket is bound to.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_LOCAL_ADDRESS,
g_param_spec_object ("local-address", NULL, NULL,
G_TYPE_SOCKET_ADDRESS,
G_PARAM_READABLE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:remote-address:
*
* The remote address the socket is connected to.
*
* Since: 2.22
*/
g_object_class_install_property (gobject_class, PROP_REMOTE_ADDRESS,
g_param_spec_object ("remote-address", NULL, NULL,
G_TYPE_SOCKET_ADDRESS,
G_PARAM_READABLE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:timeout:
*
* The timeout in seconds on socket I/O
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_TIMEOUT,
g_param_spec_uint ("timeout", NULL, NULL,
0,
G_MAXUINT,
0,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:broadcast:
*
* Whether the socket should allow sending to broadcast addresses.
*
* Since: 2.32
*/
g_object_class_install_property (gobject_class, PROP_BROADCAST,
g_param_spec_boolean ("broadcast", NULL, NULL,
FALSE,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:ttl:
*
* Time-to-live for outgoing unicast packets
*
* Since: 2.32
*/
g_object_class_install_property (gobject_class, PROP_TTL,
g_param_spec_uint ("ttl", NULL, NULL,
0, G_MAXUINT, 0,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:multicast-loopback:
*
* Whether outgoing multicast packets loop back to the local host.
*
* Since: 2.32
*/
g_object_class_install_property (gobject_class, PROP_MULTICAST_LOOPBACK,
g_param_spec_boolean ("multicast-loopback", NULL, NULL,
TRUE,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GSocket:multicast-ttl:
*
* Time-to-live out outgoing multicast packets
*
* Since: 2.32
*/
g_object_class_install_property (gobject_class, PROP_MULTICAST_TTL,
g_param_spec_uint ("multicast-ttl", NULL, NULL,
0, G_MAXUINT, 1,
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
}
static void
g_socket_initable_iface_init (GInitableIface *iface)
{
iface->init = g_socket_initable_init;
}
static void
g_socket_datagram_based_iface_init (GDatagramBasedInterface *iface)
{
iface->receive_messages = g_socket_datagram_based_receive_messages;
iface->send_messages = g_socket_datagram_based_send_messages;
iface->create_source = g_socket_datagram_based_create_source;
iface->condition_check = g_socket_datagram_based_condition_check;
iface->condition_wait = g_socket_datagram_based_condition_wait;
}
static void
g_socket_init (GSocket *socket)
{
socket->priv = g_socket_get_instance_private (socket);
socket->priv->fd = -1;
socket->priv->blocking = TRUE;
socket->priv->listen_backlog = 10;
socket->priv->construct_error = NULL;
#ifdef G_OS_WIN32
socket->priv->event = WSA_INVALID_EVENT;
g_mutex_init (&socket->priv->win32_source_lock);
g_cond_init (&socket->priv->win32_source_cond);
#endif
}
static gboolean
g_socket_initable_init (GInitable *initable,
GCancellable *cancellable,
GError **error)
{
GSocket *socket;
g_return_val_if_fail (G_IS_SOCKET (initable), FALSE);
socket = G_SOCKET (initable);
if (cancellable != NULL)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
_("Cancellable initialization not supported"));
return FALSE;
}
socket->priv->inited = TRUE;
if (socket->priv->construct_error)
{
if (error)
*error = g_error_copy (socket->priv->construct_error);
return FALSE;
}
return TRUE;
}
static gboolean
check_datagram_based (GDatagramBased *self,
GError **error)
{
switch (g_socket_get_socket_type (G_SOCKET (self)))
{
case G_SOCKET_TYPE_INVALID:
case G_SOCKET_TYPE_STREAM:
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
_("Cannot use datagram operations on a non-datagram "
"socket."));
return FALSE;
case G_SOCKET_TYPE_DATAGRAM:
case G_SOCKET_TYPE_SEQPACKET:
/* Fall through. */
break;
}
/* Due to us sharing #GSocketSource with the #GSocket implementation, it is
* pretty tricky to split out #GSocket:timeout so that it does not affect
* #GDatagramBased operations (but still affects #GSocket operations). It is
* not worth that effort — just disallow it and require the user to specify
* timeouts on a per-operation basis. */
if (g_socket_get_timeout (G_SOCKET (self)) != 0)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
_("Cannot use datagram operations on a socket with a "
"timeout set."));
return FALSE;
}
return TRUE;
}
static gint
g_socket_datagram_based_receive_messages (GDatagramBased *self,
GInputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error)
{
if (!check_datagram_based (self, error))
return FALSE;
return g_socket_receive_messages_with_timeout (G_SOCKET (self), messages,
num_messages, flags, timeout_us,
cancellable, error);
}
static gint
g_socket_datagram_based_send_messages (GDatagramBased *self,
GOutputMessage *messages,
guint num_messages,
gint flags,
gint64 timeout_us,
GCancellable *cancellable,
GError **error)
{
if (!check_datagram_based (self, error))
return FALSE;
return g_socket_send_messages_with_timeout (G_SOCKET (self), messages,
num_messages, flags, timeout_us,
cancellable, error);
}
static GSource *
g_socket_datagram_based_create_source (GDatagramBased *self,
GIOCondition condition,
GCancellable *cancellable)
{
if (!check_datagram_based (self, NULL))
return NULL;
return g_socket_create_source (G_SOCKET (self), condition, cancellable);
}
static GIOCondition
g_socket_datagram_based_condition_check (GDatagramBased *datagram_based,
GIOCondition condition)
{
if (!check_datagram_based (datagram_based, NULL))
return G_IO_ERR;
return g_socket_condition_check (G_SOCKET (datagram_based), condition);
}
static gboolean
g_socket_datagram_based_condition_wait (GDatagramBased *datagram_based,
GIOCondition condition,
gint64 timeout_us,
GCancellable *cancellable,
GError **error)
{
if (!check_datagram_based (datagram_based, error))
return FALSE;
return g_socket_condition_timed_wait (G_SOCKET (datagram_based), condition,
timeout_us, cancellable, error);
}
/**
* g_socket_new:
* @family: the socket family to use, e.g. %G_SOCKET_FAMILY_IPV4.
* @type: the socket type to use.
* @protocol: the id of the protocol to use, or 0 for default.
* @error: #GError for error reporting, or %NULL to ignore.
*
* Creates a new #GSocket with the defined family, type and protocol.
* If @protocol is 0 (%G_SOCKET_PROTOCOL_DEFAULT) the default protocol type
* for the family and type is used.
*
* The @protocol is a family and type specific int that specifies what
* kind of protocol to use. #GSocketProtocol lists several common ones.
* Many families only support one protocol, and use 0 for this, others
* support several and using 0 means to use the default protocol for
* the family and type.
*
* The protocol id is passed directly to the operating
* system, so you can use protocols not listed in #GSocketProtocol if you
* know the protocol number used for it.
*
* Returns: a #GSocket or %NULL on error.
* Free the returned object with g_object_unref().
*
* Since: 2.22
*/
GSocket *
g_socket_new (GSocketFamily family,
GSocketType type,
GSocketProtocol protocol,
GError **error)
{
return G_SOCKET (g_initable_new (G_TYPE_SOCKET,
NULL, error,
"family", family,
"type", type,
"protocol", protocol,
NULL));
}
/**
* g_socket_new_from_fd:
* @fd: a native socket file descriptor.
* @error: #GError for error reporting, or %NULL to ignore.
*
* Creates a new #GSocket from a native file descriptor
* or winsock SOCKET handle.
*
* This reads all the settings from the file descriptor so that
* all properties should work. Note that the file descriptor
* will be set to non-blocking mode, independent on the blocking
* mode of the #GSocket.
*
* On success, the returned #GSocket takes ownership of @fd. On failure, the
* caller must close @fd themselves.
*
* Since GLib 2.46, it is no longer a fatal error to call this on a non-socket
* descriptor. Instead, a GError will be set with code %G_IO_ERROR_FAILED
*
* Returns: a #GSocket or %NULL on error.
* Free the returned object with g_object_unref().
*
* Since: 2.22
*/
GSocket *
g_socket_new_from_fd (gint fd,
GError **error)
{
return G_SOCKET (g_initable_new (G_TYPE_SOCKET,
NULL, error,
"fd", fd,
NULL));
}
/**
* g_socket_set_blocking:
* @socket: a #GSocket.
* @blocking: Whether to use blocking I/O or not.
*
* Sets the blocking mode of the socket. In blocking mode
* all operations (which don’t take an explicit blocking parameter) block until
* they succeed or there is an error. In
* non-blocking mode all functions return results immediately or
* with a %G_IO_ERROR_WOULD_BLOCK error.
*
* All sockets are created in blocking mode. However, note that the
* platform level socket is always non-blocking, and blocking mode
* is a GSocket level feature.
*
* Since: 2.22
*/
void
g_socket_set_blocking (GSocket *socket,
gboolean blocking)
{
g_return_if_fail (G_IS_SOCKET (socket));
blocking = !!blocking;
if (socket->priv->blocking == blocking)
return;
socket->priv->blocking = blocking;
g_object_notify (G_OBJECT (socket), "blocking");
}
/**
* g_socket_get_blocking:
* @socket: a #GSocket.
*
* Gets the blocking mode of the socket. For details on blocking I/O,
* see g_socket_set_blocking().
*
* Returns: %TRUE if blocking I/O is used, %FALSE otherwise.
*
* Since: 2.22
*/
gboolean
g_socket_get_blocking (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
return socket->priv->blocking;
}
/**
* g_socket_set_keepalive:
* @socket: a #GSocket.
* @keepalive: Value for the keepalive flag
*
* Sets or unsets the %SO_KEEPALIVE flag on the underlying socket. When
* this flag is set on a socket, the system will attempt to verify that the
* remote socket endpoint is still present if a sufficiently long period of
* time passes with no data being exchanged. If the system is unable to
* verify the presence of the remote endpoint, it will automatically close
* the connection.
*
* This option is only functional on certain kinds of sockets. (Notably,
* %G_SOCKET_PROTOCOL_TCP sockets.)
*
* The exact time between pings is system- and protocol-dependent, but will
* normally be at least two hours. Most commonly, you would set this flag
* on a server socket if you want to allow clients to remain idle for long
* periods of time, but also want to ensure that connections are eventually
* garbage-collected if clients crash or become unreachable.
*
* Since: 2.22
*/
void
g_socket_set_keepalive (GSocket *socket,
gboolean keepalive)
{
GError *error = NULL;
g_return_if_fail (G_IS_SOCKET (socket));
keepalive = !!keepalive;
if (socket->priv->keepalive == keepalive)
return;
if (!g_socket_set_option (socket, SOL_SOCKET, SO_KEEPALIVE,
keepalive, &error))
{
g_warning ("error setting keepalive: %s", error->message);
g_error_free (error);
return;
}
socket->priv->keepalive = keepalive;
g_object_notify (G_OBJECT (socket), "keepalive");
}
/**
* g_socket_get_keepalive:
* @socket: a #GSocket.
*
* Gets the keepalive mode of the socket. For details on this,
* see g_socket_set_keepalive().
*
* Returns: %TRUE if keepalive is active, %FALSE otherwise.
*
* Since: 2.22
*/
gboolean
g_socket_get_keepalive (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
return socket->priv->keepalive;
}
/**
* g_socket_get_listen_backlog:
* @socket: a #GSocket.
*
* Gets the listen backlog setting of the socket. For details on this,
* see g_socket_set_listen_backlog().
*
* Returns: the maximum number of pending connections.
*
* Since: 2.22
*/
gint
g_socket_get_listen_backlog (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), 0);
return socket->priv->listen_backlog;
}
/**
* g_socket_set_listen_backlog:
* @socket: a #GSocket.
* @backlog: the maximum number of pending connections.
*
* Sets the maximum number of outstanding connections allowed
* when listening on this socket. If more clients than this are
* connecting to the socket and the application is not handling them
* on time then the new connections will be refused.
*
* Note that this must be called before g_socket_listen() and has no
* effect if called after that.
*
* Since: 2.22
*/
void
g_socket_set_listen_backlog (GSocket *socket,
gint backlog)
{
g_return_if_fail (G_IS_SOCKET (socket));
g_return_if_fail (!socket->priv->listening);
if (backlog != socket->priv->listen_backlog)
{
socket->priv->listen_backlog = backlog;
g_object_notify (G_OBJECT (socket), "listen-backlog");
}
}
/**
* g_socket_get_timeout:
* @socket: a #GSocket.
*
* Gets the timeout setting of the socket. For details on this, see
* g_socket_set_timeout().
*
* Returns: the timeout in seconds
*
* Since: 2.26
*/
guint
g_socket_get_timeout (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), 0);
return socket->priv->timeout;
}
/**
* g_socket_set_timeout:
* @socket: a #GSocket.
* @timeout: the timeout for @socket, in seconds, or 0 for none
*
* Sets the time in seconds after which I/O operations on @socket will
* time out if they have not yet completed.
*
* On a blocking socket, this means that any blocking #GSocket
* operation will time out after @timeout seconds of inactivity,
* returning %G_IO_ERROR_TIMED_OUT.
*
* On a non-blocking socket, calls to g_socket_condition_wait() will
* also fail with %G_IO_ERROR_TIMED_OUT after the given time. Sources
* created with g_socket_create_source() will trigger after
* @timeout seconds of inactivity, with the requested condition
* set, at which point calling g_socket_receive(), g_socket_send(),
* g_socket_check_connect_result(), etc, will fail with
* %G_IO_ERROR_TIMED_OUT.
*
* If @timeout is 0 (the default), operations will never time out
* on their own.
*
* Note that if an I/O operation is interrupted by a signal, this may
* cause the timeout to be reset.
*
* Since: 2.26
*/
void
g_socket_set_timeout (GSocket *socket,
guint timeout)
{
g_return_if_fail (G_IS_SOCKET (socket));
if (timeout != socket->priv->timeout)
{
socket->priv->timeout = timeout;
g_object_notify (G_OBJECT (socket), "timeout");
}
}
/**
* g_socket_get_ttl:
* @socket: a #GSocket.
*
* Gets the unicast time-to-live setting on @socket; see
* g_socket_set_ttl() for more details.
*
* Returns: the time-to-live setting on @socket
*
* Since: 2.32
*/
guint
g_socket_get_ttl (GSocket *socket)
{
GError *error = NULL;
gint value;
g_return_val_if_fail (G_IS_SOCKET (socket), 0);
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_get_option (socket, IPPROTO_IP, IP_TTL,
&value, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_get_option (socket, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
&value, &error);
}
else
g_return_val_if_reached (0);
if (error)
{
g_warning ("error getting unicast ttl: %s", error->message);
g_error_free (error);
return 0;
}
return value;
}
/**
* g_socket_set_ttl:
* @socket: a #GSocket.
* @ttl: the time-to-live value for all unicast packets on @socket
*
* Sets the time-to-live for outgoing unicast packets on @socket.
* By default the platform-specific default value is used.
*
* Since: 2.32
*/
void
g_socket_set_ttl (GSocket *socket,
guint ttl)
{
GError *error = NULL;
g_return_if_fail (G_IS_SOCKET (socket));
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_set_option (socket, IPPROTO_IP, IP_TTL,
ttl, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_set_option (socket, IPPROTO_IP, IP_TTL,
ttl, NULL);
g_socket_set_option (socket, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
ttl, &error);
}
else
g_return_if_reached ();
if (error)
{
g_warning ("error setting unicast ttl: %s", error->message);
g_error_free (error);
return;
}
g_object_notify (G_OBJECT (socket), "ttl");
}
/**
* g_socket_get_broadcast:
* @socket: a #GSocket.
*
* Gets the broadcast setting on @socket; if %TRUE,
* it is possible to send packets to broadcast
* addresses.
*
* Returns: the broadcast setting on @socket
*
* Since: 2.32
*/
gboolean
g_socket_get_broadcast (GSocket *socket)
{
GError *error = NULL;
gint value;
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
if (!g_socket_get_option (socket, SOL_SOCKET, SO_BROADCAST,
&value, &error))
{
g_warning ("error getting broadcast: %s", error->message);
g_error_free (error);
return FALSE;
}
return !!value;
}
/**
* g_socket_set_broadcast:
* @socket: a #GSocket.
* @broadcast: whether @socket should allow sending to broadcast
* addresses
*
* Sets whether @socket should allow sending to broadcast addresses.
* This is %FALSE by default.
*
* Since: 2.32
*/
void
g_socket_set_broadcast (GSocket *socket,
gboolean broadcast)
{
GError *error = NULL;
g_return_if_fail (G_IS_SOCKET (socket));
broadcast = !!broadcast;
if (!g_socket_set_option (socket, SOL_SOCKET, SO_BROADCAST,
broadcast, &error))
{
g_warning ("error setting broadcast: %s", error->message);
g_error_free (error);
return;
}
g_object_notify (G_OBJECT (socket), "broadcast");
}
/**
* g_socket_get_multicast_loopback:
* @socket: a #GSocket.
*
* Gets the multicast loopback setting on @socket; if %TRUE (the
* default), outgoing multicast packets will be looped back to
* multicast listeners on the same host.
*
* Returns: the multicast loopback setting on @socket
*
* Since: 2.32
*/
gboolean
g_socket_get_multicast_loopback (GSocket *socket)
{
GError *error = NULL;
gint value;
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_get_option (socket, IPPROTO_IP, IP_MULTICAST_LOOP,
&value, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_get_option (socket, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&value, &error);
}
else
g_return_val_if_reached (FALSE);
if (error)
{
g_warning ("error getting multicast loopback: %s", error->message);
g_error_free (error);
return FALSE;
}
return !!value;
}
/**
* g_socket_set_multicast_loopback:
* @socket: a #GSocket.
* @loopback: whether @socket should receive messages sent to its
* multicast groups from the local host
*
* Sets whether outgoing multicast packets will be received by sockets
* listening on that multicast address on the same host. This is %TRUE
* by default.
*
* Since: 2.32
*/
void
g_socket_set_multicast_loopback (GSocket *socket,
gboolean loopback)
{
GError *error = NULL;
g_return_if_fail (G_IS_SOCKET (socket));
loopback = !!loopback;
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_set_option (socket, IPPROTO_IP, IP_MULTICAST_LOOP,
loopback, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_set_option (socket, IPPROTO_IP, IP_MULTICAST_LOOP,
loopback, NULL);
g_socket_set_option (socket, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
loopback, &error);
}
else
g_return_if_reached ();
if (error)
{
g_warning ("error setting multicast loopback: %s", error->message);
g_error_free (error);
return;
}
g_object_notify (G_OBJECT (socket), "multicast-loopback");
}
/**
* g_socket_get_multicast_ttl:
* @socket: a #GSocket.
*
* Gets the multicast time-to-live setting on @socket; see
* g_socket_set_multicast_ttl() for more details.
*
* Returns: the multicast time-to-live setting on @socket
*
* Since: 2.32
*/
guint
g_socket_get_multicast_ttl (GSocket *socket)
{
GError *error = NULL;
gint value;
g_return_val_if_fail (G_IS_SOCKET (socket), 0);
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_get_option (socket, IPPROTO_IP, IP_MULTICAST_TTL,
&value, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_get_option (socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&value, &error);
}
else
g_return_val_if_reached (FALSE);
if (error)
{
g_warning ("error getting multicast ttl: %s", error->message);
g_error_free (error);
return FALSE;
}
return value;
}
/**
* g_socket_set_multicast_ttl:
* @socket: a #GSocket.
* @ttl: the time-to-live value for all multicast datagrams on @socket
*
* Sets the time-to-live for outgoing multicast datagrams on @socket.
* By default, this is 1, meaning that multicast packets will not leave
* the local network.
*
* Since: 2.32
*/
void
g_socket_set_multicast_ttl (GSocket *socket,
guint ttl)
{
GError *error = NULL;
g_return_if_fail (G_IS_SOCKET (socket));
if (socket->priv->family == G_SOCKET_FAMILY_IPV4)
{
g_socket_set_option (socket, IPPROTO_IP, IP_MULTICAST_TTL,
ttl, &error);
}
else if (socket->priv->family == G_SOCKET_FAMILY_IPV6)
{
g_socket_set_option (socket, IPPROTO_IP, IP_MULTICAST_TTL,
ttl, NULL);
g_socket_set_option (socket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
ttl, &error);
}
else
g_return_if_reached ();
if (error)
{
g_warning ("error setting multicast ttl: %s", error->message);
g_error_free (error);
return;
}
g_object_notify (G_OBJECT (socket), "multicast-ttl");
}
/**
* g_socket_get_family:
* @socket: a #GSocket.
*
* Gets the socket family of the socket.
*
* Returns: a #GSocketFamily
*
* Since: 2.22
*/
GSocketFamily
g_socket_get_family (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), G_SOCKET_FAMILY_INVALID);
return socket->priv->family;
}
/**
* g_socket_get_socket_type:
* @socket: a #GSocket.
*
* Gets the socket type of the socket.
*
* Returns: a #GSocketType
*
* Since: 2.22
*/
GSocketType
g_socket_get_socket_type (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), G_SOCKET_TYPE_INVALID);
return socket->priv->type;
}
/**
* g_socket_get_protocol:
* @socket: a #GSocket.
*
* Gets the socket protocol id the socket was created with.
* In case the protocol is unknown, -1 is returned.
*
* Returns: a protocol id, or -1 if unknown
*
* Since: 2.22
*/
GSocketProtocol
g_socket_get_protocol (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), -1);
return socket->priv->protocol;
}
/**
* g_socket_get_fd:
* @socket: a #GSocket.
*
* Returns the underlying OS socket object. On unix this
* is a socket file descriptor, and on Windows this is
* a Winsock2 SOCKET handle. This may be useful for
* doing platform specific or otherwise unusual operations
* on the socket.
*
* Returns: the file descriptor of the socket.
*
* Since: 2.22
*/
int
g_socket_get_fd (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), -1);
return socket->priv->fd;
}
/**
* g_socket_get_local_address:
* @socket: a #GSocket.
* @error: #GError for error reporting, or %NULL to ignore.
*
* Try to get the local address of a bound socket. This is only
* useful if the socket has been bound to a local address,
* either explicitly or implicitly when connecting.
*
* Returns: (transfer full): a #GSocketAddress or %NULL on error.
* Free the returned object with g_object_unref().
*
* Since: 2.22
*/
GSocketAddress *
g_socket_get_local_address (GSocket *socket,
GError **error)
{
union {
struct sockaddr_storage storage;
struct sockaddr sa;
} buffer;
socklen_t len = sizeof (buffer);
g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
if (getsockname (socket->priv->fd, &buffer.sa, &len) < 0)
{
int errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
_("could not get local address: %s"), socket_strerror (errsv));
return NULL;
}
return g_socket_address_new_from_native (&buffer.storage, len);
}
/**
* g_socket_get_remote_address:
* @socket: a #GSocket.
* @error: #GError for error reporting, or %NULL to ignore.
*
* Try to get the remote address of a connected socket. This is only
* useful for connection oriented sockets that have been connected.
*
* Returns: (transfer full): a #GSocketAddress or %NULL on error.
* Free the returned object with g_object_unref().
*
* Since: 2.22
*/
GSocketAddress *
g_socket_get_remote_address (GSocket *socket,
GError **error)
{
union {
struct sockaddr_storage storage;
struct sockaddr sa;
} buffer;
socklen_t len = sizeof (buffer);
g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
if (socket->priv->connect_pending)
{
if (!g_socket_check_connect_result (socket, error))
return NULL;
else
socket->priv->connect_pending = FALSE;
}
if (!socket->priv->remote_address)
{
if (getpeername (socket->priv->fd, &buffer.sa, &len) < 0)
{
int errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
_("could not get remote address: %s"), socket_strerror (errsv));
return NULL;
}
socket->priv->remote_address = g_socket_address_new_from_native (&buffer.storage, len);
}
return g_object_ref (socket->priv->remote_address);
}
/**
* g_socket_is_connected:
* @socket: a #GSocket.
*
* Check whether the socket is connected. This is only useful for
* connection-oriented sockets.
*
* If using g_socket_shutdown(), this function will return %TRUE until the
* socket has been shut down for reading and writing. If you do a non-blocking
* connect, this function will not return %TRUE until after you call
* g_socket_check_connect_result().
*
* Returns: %TRUE if socket is connected, %FALSE otherwise.
*
* Since: 2.22
*/
gboolean
g_socket_is_connected (GSocket *socket)
{
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
return (socket->priv->connected_read || socket->priv->connected_write);
}
/**
* g_socket_listen:
* @socket: a #GSocket.
* @error: #GError for error reporting, or %NULL to ignore.
*
* Marks the socket as a server socket, i.e. a socket that is used
* to accept incoming requests using g_socket_accept().
*
* Before calling this the socket must be bound to a local address using
* g_socket_bind().
*
* To set the maximum amount of outstanding clients, use
* g_socket_set_listen_backlog().
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.22
*/
gboolean
g_socket_listen (GSocket *socket,
GError **error)
{
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
if (!check_socket (socket, error))
return FALSE;
if (listen (socket->priv->fd, socket->priv->listen_backlog) < 0)
{
int errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
_("could not listen: %s"), socket_strerror (errsv));
return FALSE;
}
socket->priv->listening = TRUE;
return TRUE;
}
/**
* g_socket_bind:
* @socket: a #GSocket.
* @address: a #GSocketAddress specifying the local address.
* @allow_reuse: whether to allow reusing this address
* @error: #GError for error reporting, or %NULL to ignore.
*
* When a socket is created it is attached to an address family, but it
* doesn't have an address in this family. g_socket_bind() assigns the
* address (sometimes called name) of the socket.
*
* It is generally required to bind to a local address before you can
* receive connections. (See g_socket_listen() and g_socket_accept() ).
* In certain situations, you may also want to bind a socket that will be
* used to initiate connections, though this is not normally required.
*
* If @socket is a TCP socket, then @allow_reuse controls the setting
* of the `SO_REUSEADDR` socket option; normally it should be %TRUE for
* server sockets (sockets that you will eventually call
* g_socket_accept() on), and %FALSE for client sockets. (Failing to
* set this flag on a server socket may cause g_socket_bind() to return
* %G_IO_ERROR_ADDRESS_IN_USE if the server program is stopped and then
* immediately restarted.)
*
* If @socket is a UDP socket, then @allow_reuse determines whether or
* not other UDP sockets can be bound to the same address at the same
* time. In particular, you can have several UDP sockets bound to the
* same address, and they will all receive all of the multicast and
* broadcast packets sent to that address. (The behavior of unicast
* UDP packets to an address with multiple listeners is not defined.)
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.22
*/
gboolean
g_socket_bind (GSocket *socket,
GSocketAddress *address,
gboolean reuse_address,
GError **error)
{
union {
struct sockaddr_storage storage;
struct sockaddr sa;
} addr;
gboolean so_reuseaddr;
#ifdef SO_REUSEPORT
gboolean so_reuseport;
#endif
g_return_val_if_fail (G_IS_SOCKET (socket) && G_IS_SOCKET_ADDRESS (address), FALSE);
if (!check_socket (socket, error))
return FALSE;
if (!g_socket_address_to_native (address, &addr.storage, sizeof addr, error))
return FALSE;
/* On Windows, SO_REUSEADDR has the semantics we want for UDP
* sockets, but has nasty side effects we don't want for TCP
* sockets.
*
* On other platforms, we set SO_REUSEPORT, if it exists, for
* UDP sockets, and SO_REUSEADDR for all sockets, hoping that
* if SO_REUSEPORT doesn't exist, then SO_REUSEADDR will have
* the desired semantics on UDP (as it does on Linux, although
* Linux has SO_REUSEPORT too as of 3.9).
*/
#ifdef G_OS_WIN32
so_reuseaddr = reuse_address && (socket->priv->type == G_SOCKET_TYPE_DATAGRAM);
#else
so_reuseaddr = !!reuse_address;
#endif
#ifdef SO_REUSEPORT
so_reuseport = reuse_address && (socket->priv->type == G_SOCKET_TYPE_DATAGRAM);
#endif
/* Ignore errors here, the only likely error is "not supported", and
* this is a "best effort" thing mainly.
*/
g_socket_set_option (socket, SOL_SOCKET, SO_REUSEADDR, so_reuseaddr, NULL);
#ifdef SO_REUSEPORT
g_socket_set_option (socket, SOL_SOCKET, SO_REUSEPORT, so_reuseport, NULL);
#endif
if (bind (socket->priv->fd, &addr.sa,
g_socket_address_get_native_size (address)) < 0)
{
int errsv = get_socket_errno ();
gchar *address_string = address_to_string (address);
g_set_error (error,
G_IO_ERROR, socket_io_error_from_errno (errsv),
_("Error binding to address %s: %s"),
address_string, socket_strerror (errsv));
g_free (address_string);
return FALSE;
}
return TRUE;
}
#ifdef G_OS_WIN32
static gulong
g_socket_w32_get_adapter_ipv4_addr (const gchar *name_or_ip)
{
ULONG bufsize = 15000; /* MS-recommended initial bufsize */
DWORD ret = ERROR_BUFFER_OVERFLOW;
unsigned int malloc_iterations = 0;
PIP_ADAPTER_ADDRESSES addr_buf = NULL, eth_adapter;
wchar_t *wchar_name_or_ip = NULL;
gulong ip_result = 0;
NET_IFINDEX if_index;
/*
* For Windows OS only - return adapter IPv4 address in network byte order.
*
* Input string can be either friendly name of adapter, IP address of adapter,
* indextoname, or fullname of adapter.
* Example:
* 192.168.1.109 ===> IP address given directly,
* convert directly with inet_addr() function
* Wi-Fi ===> Adapter friendly name "Wi-Fi",
* scan with GetAdapterAddresses and adapter->FriendlyName
* ethernet_32774 ===> Adapter name as returned by if_indextoname
* {33E8F5CD-BAEA-4214-BE13-B79AB8080CAB} ===> Adaptername,
* as returned in GetAdapterAddresses and adapter->AdapterName
*/
/* Step 1: Check if string is an IP address: */
if (inet_pton (AF_INET, name_or_ip, &ip_result) == 1)
return ip_result; /* Success, IP address string was given directly */
/*
* Step 2: Check if name represents a valid Interface index (e.g. ethernet_75521)
* function if_nametoindex will return >=1 if a valid index, or 0=no match
* valid index will be used later in GetAdaptersAddress loop for lookup of adapter IP address
*/
if_index = if_nametoindex (name_or_ip);
/* Step 3: Prepare wchar string for friendly name comparison */
if (if_index == 0)
{
size_t if_name_len = strlen (name_or_ip);
if (if_name_len >= MAX_ADAPTER_NAME_LENGTH + 4)
return INADDR_NONE;
/* Name-check only needed if index=0... */
wchar_name_or_ip = (wchar_t *) g_try_malloc ((if_name_len + 1) * sizeof(wchar_t));
if (wchar_name_or_ip)
mbstowcs (wchar_name_or_ip, name_or_ip, if_name_len + 1);
/* NOTE: Even if malloc fails here, some comparisons can still be done later... so no exit here! */
}
/*
* Step 4: Allocate memory and get adapter addresses.
* Buffer allocation loop recommended by MS, since size can be dynamic
* https://docs.microsoft.com/en-us/windows/desktop/api/iphlpapi/nf-iphlpapi-getadaptersaddresses
*/
#define MAX_ALLOC_ITERATIONS 3
do
{
malloc_iterations++;
addr_buf = (PIP_ADAPTER_ADDRESSES) g_try_realloc (addr_buf, bufsize);
if (addr_buf)
ret = GetAdaptersAddresses (AF_UNSPEC, GAA_FLAG_INCLUDE_PREFIX, NULL, addr_buf, &bufsize);
}
while (addr_buf &&
ret == ERROR_BUFFER_OVERFLOW &&
malloc_iterations < MAX_ALLOC_ITERATIONS);
#undef MAX_ALLOC_ITERATIONS
if (addr_buf == 0 || ret != NO_ERROR)
{
g_free (addr_buf);
g_free (wchar_name_or_ip);
return INADDR_NONE;
}
/* Step 5: Loop through adapters and check match for index or name */
for (eth_adapter = addr_buf; eth_adapter != NULL; eth_adapter = eth_adapter->Next)
{
/* Check if match for interface index/name: */
gboolean any_match = (if_index > 0) && (eth_adapter->IfIndex == if_index);
/* Check if match for friendly name - but only if NO if_index! */
if (!any_match && if_index == 0 && eth_adapter->FriendlyName &&
eth_adapter->FriendlyName[0] != 0 && wchar_name_or_ip != NULL)
any_match = (_wcsicmp (eth_adapter->FriendlyName, wchar_name_or_ip) == 0);
/* Check if match for adapter low level name - but only if NO if_index: */
if (!any_match && if_index == 0 && eth_adapter->AdapterName &&
eth_adapter->AdapterName[0] != 0)
any_match = (stricmp (eth_adapter->AdapterName, name_or_ip) == 0);
if (any_match)
{
/* We have match for this adapter, lets get its local unicast IP address! */
PIP_ADAPTER_UNICAST_ADDRESS uni_addr;
for (uni_addr = eth_adapter->FirstUnicastAddress;
uni_addr != NULL; uni_addr = uni_addr->Next)
{
if (uni_addr->Address.lpSockaddr->sa_family == AF_INET)
{
ip_result = ((PSOCKADDR_IN) uni_addr->Address.lpSockaddr)->sin_addr.S_un.S_addr;
break; /* finished, exit unicast addr loop */
}
}
}
}
g_free (addr_buf);
g_free (wchar_name_or_ip);
return ip_result;
}
#endif
static gboolean
g_socket_multicast_group_operation (GSocket *socket,
GInetAddress *group,
gboolean source_specific,
const gchar *iface,
gboolean join_group,
GError **error)
{
const guint8 *native_addr;
gint optname, result;
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
g_return_val_if_fail (socket->priv->type == G_SOCKET_TYPE_DATAGRAM, FALSE);
g_return_val_if_fail (G_IS_INET_ADDRESS (group), FALSE);
if (!check_socket (socket, error))
return FALSE;
native_addr = g_inet_address_to_bytes (group);
if (g_inet_address_get_family (group) == G_SOCKET_FAMILY_IPV4)
{
#ifdef HAVE_IP_MREQN
struct ip_mreqn mc_req;
#else
struct ip_mreq mc_req;
#endif
memset (&mc_req, 0, sizeof (mc_req));
memcpy (&mc_req.imr_multiaddr, native_addr, sizeof (struct in_addr));
#ifdef HAVE_IP_MREQN
if (iface)
mc_req.imr_ifindex = if_nametoindex (iface);
else
mc_req.imr_ifindex = 0; /* Pick any. */
#elif defined(G_OS_WIN32)
if (iface)
mc_req.imr_interface.s_addr = g_socket_w32_get_adapter_ipv4_addr (iface);
else
mc_req.imr_interface.s_addr = g_htonl (INADDR_ANY);
#else
mc_req.imr_interface.s_addr = g_htonl (INADDR_ANY);
#endif
if (source_specific)
{
#ifdef IP_ADD_SOURCE_MEMBERSHIP
optname = join_group ? IP_ADD_SOURCE_MEMBERSHIP : IP_DROP_SOURCE_MEMBERSHIP;
#else
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
_("No support for source-specific multicast"));
return FALSE;
#endif
}
else
optname = join_group ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP;
result = setsockopt (socket->priv->fd, IPPROTO_IP, optname,
&mc_req, sizeof (mc_req));
}
else if (g_inet_address_get_family (group) == G_SOCKET_FAMILY_IPV6)
{
struct ipv6_mreq mc_req_ipv6;
memset (&mc_req_ipv6, 0, sizeof (mc_req_ipv6));
memcpy (&mc_req_ipv6.ipv6mr_multiaddr, native_addr, sizeof (struct in6_addr));
#ifdef HAVE_IF_NAMETOINDEX
if (iface)
mc_req_ipv6.ipv6mr_interface = if_nametoindex (iface);
else
#endif
mc_req_ipv6.ipv6mr_interface = 0;
optname = join_group ? IPV6_JOIN_GROUP : IPV6_LEAVE_GROUP;
result = setsockopt (socket->priv->fd, IPPROTO_IPV6, optname,
&mc_req_ipv6, sizeof (mc_req_ipv6));
}
else
g_return_val_if_reached (FALSE);
if (result < 0)
{
int errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
socket_strerror (errsv));
return FALSE;
}
return TRUE;
}
/**
* g_socket_join_multicast_group:
* @socket: a #GSocket.
* @group: a #GInetAddress specifying the group address to join.
* @iface: (nullable): Name of the interface to use, or %NULL
* @source_specific: %TRUE if source-specific multicast should be used
* @error: #GError for error reporting, or %NULL to ignore.
*
* Registers @socket to receive multicast messages sent to @group.
* @socket must be a %G_SOCKET_TYPE_DATAGRAM socket, and must have
* been bound to an appropriate interface and port with
* g_socket_bind().
*
* If @iface is %NULL, the system will automatically pick an interface
* to bind to based on @group.
*
* If @source_specific is %TRUE, source-specific multicast as defined
* in RFC 4604 is used. Note that on older platforms this may fail
* with a %G_IO_ERROR_NOT_SUPPORTED error.
*
* To bind to a given source-specific multicast address, use
* g_socket_join_multicast_group_ssm() instead.
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.32
*/
gboolean
g_socket_join_multicast_group (GSocket *socket,
GInetAddress *group,
gboolean source_specific,
const gchar *iface,
GError **error)
{
return g_socket_multicast_group_operation (socket, group, source_specific, iface, TRUE, error);
}
/**
* g_socket_leave_multicast_group:
* @socket: a #GSocket.
* @group: a #GInetAddress specifying the group address to leave.
* @iface: (nullable): Interface used
* @source_specific: %TRUE if source-specific multicast was used
* @error: #GError for error reporting, or %NULL to ignore.
*
* Removes @socket from the multicast group defined by @group, @iface,
* and @source_specific (which must all have the same values they had
* when you joined the group).
*
* @socket remains bound to its address and port, and can still receive
* unicast messages after calling this.
*
* To unbind to a given source-specific multicast address, use
* g_socket_leave_multicast_group_ssm() instead.
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.32
*/
gboolean
g_socket_leave_multicast_group (GSocket *socket,
GInetAddress *group,
gboolean source_specific,
const gchar *iface,
GError **error)
{
return g_socket_multicast_group_operation (socket, group, source_specific, iface, FALSE, error);
}
static gboolean
g_socket_multicast_group_operation_ssm (GSocket *socket,
GInetAddress *group,
GInetAddress *source_specific,
const gchar *iface,
gboolean join_group,
GError **error)
{
gint result;
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
g_return_val_if_fail (socket->priv->type == G_SOCKET_TYPE_DATAGRAM, FALSE);
g_return_val_if_fail (G_IS_INET_ADDRESS (group), FALSE);
g_return_val_if_fail (iface == NULL || *iface != '\0', FALSE);
g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
if (!source_specific)
{
return g_socket_multicast_group_operation (socket, group, FALSE, iface,
join_group, error);
}
if (!check_socket (socket, error))
return FALSE;
switch (g_inet_address_get_family (group))
{
case G_SOCKET_FAMILY_INVALID:
case G_SOCKET_FAMILY_UNIX:
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
_("Unsupported socket family"));
return FALSE;
}
break;
case G_SOCKET_FAMILY_IPV4:
{
#ifdef IP_ADD_SOURCE_MEMBERSHIP
#ifdef BROKEN_IP_MREQ_SOURCE_STRUCT
#define S_ADDR_FIELD(src) src.imr_interface
#else
#define S_ADDR_FIELD(src) src.imr_interface.s_addr
#endif
gint optname;
struct ip_mreq_source mc_req_src;
if (g_inet_address_get_family (source_specific) !=
G_SOCKET_FAMILY_IPV4)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
_("source-specific not an IPv4 address"));
return FALSE;
}
memset (&mc_req_src, 0, sizeof (mc_req_src));
/* By default use the default IPv4 multicast interface. */
S_ADDR_FIELD(mc_req_src) = g_htonl (INADDR_ANY);
if (iface)
{
#if defined(G_OS_WIN32)
S_ADDR_FIELD(mc_req_src) = g_socket_w32_get_adapter_ipv4_addr (iface);
#elif defined (HAVE_SIOCGIFADDR)
int ret;
struct ifreq ifr;
struct sockaddr_in *iface_addr;
size_t if_name_len = strlen (iface);
memset (&ifr, 0, sizeof (ifr));
if (if_name_len >= sizeof (ifr.ifr_name))
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FILENAME_TOO_LONG,
_("Interface name too long"));
return FALSE;
}
memcpy (ifr.ifr_name, iface, if_name_len);
/* Get the IPv4 address of the given network interface name. */
ret = ioctl (socket->priv->fd, SIOCGIFADDR, &ifr);
if (ret < 0)
{
int errsv = errno;
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errsv),
_("Interface not found: %s"), g_strerror (errsv));
return FALSE;
}
iface_addr = (struct sockaddr_in *) &ifr.ifr_addr;
S_ADDR_FIELD(mc_req_src) = iface_addr->sin_addr.s_addr;
#endif /* defined(G_OS_WIN32) && defined (HAVE_IF_NAMETOINDEX) */
}
g_assert (g_inet_address_get_native_size (group) == sizeof (mc_req_src.imr_multiaddr));
memcpy (&mc_req_src.imr_multiaddr, g_inet_address_to_bytes (group),
g_inet_address_get_native_size (group));
g_assert (g_inet_address_get_native_size (source_specific) == sizeof (mc_req_src.imr_sourceaddr));
memcpy (&mc_req_src.imr_sourceaddr,
g_inet_address_to_bytes (source_specific),
g_inet_address_get_native_size (source_specific));
optname =
join_group ? IP_ADD_SOURCE_MEMBERSHIP : IP_DROP_SOURCE_MEMBERSHIP;
result = setsockopt (socket->priv->fd, IPPROTO_IP, optname,
&mc_req_src, sizeof (mc_req_src));
#undef S_ADDR_FIELD
#else
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
_("No support for IPv4 source-specific multicast"));
return FALSE;
#endif /* IP_ADD_SOURCE_MEMBERSHIP */
}
break;
case G_SOCKET_FAMILY_IPV6:
{
#ifdef MCAST_JOIN_SOURCE_GROUP
gboolean res;
gint optname;
struct group_source_req mc_req_src;
GSocketAddress *saddr_group, *saddr_source_specific;
guint iface_index = 0;
#if defined (HAVE_IF_NAMETOINDEX)
if (iface)
{
iface_index = if_nametoindex (iface);
if (iface_index == 0)
{
int errsv = errno;
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errsv),
_("Interface not found: %s"), g_strerror (errsv));
return FALSE;
}
}
#endif /* defined (HAVE_IF_NAMETOINDEX) */
mc_req_src.gsr_interface = iface_index;
saddr_group = g_inet_socket_address_new (group, 0);
res = g_socket_address_to_native (saddr_group, &mc_req_src.gsr_group,
sizeof (mc_req_src.gsr_group),
error);
g_object_unref (saddr_group);
if (!res)
return FALSE;
saddr_source_specific = g_inet_socket_address_new (source_specific, 0);
res = g_socket_address_to_native (saddr_source_specific,
&mc_req_src.gsr_source,
sizeof (mc_req_src.gsr_source),
error);
g_object_unref (saddr_source_specific);
if (!res)
return FALSE;
optname =
join_group ? MCAST_JOIN_SOURCE_GROUP : MCAST_LEAVE_SOURCE_GROUP;
result = setsockopt (socket->priv->fd, IPPROTO_IPV6, optname,
&mc_req_src, sizeof (mc_req_src));
#else
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
_("No support for IPv6 source-specific multicast"));
return FALSE;
#endif /* MCAST_JOIN_SOURCE_GROUP */
}
break;
default:
g_return_val_if_reached (FALSE);
}
if (result < 0)
{
int errsv = get_socket_errno ();
g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
join_group ?
_("Error joining multicast group: %s") :
_("Error leaving multicast group: %s"),
socket_strerror (errsv));
return FALSE;
}
return TRUE;
}
/**
* g_socket_join_multicast_group_ssm:
* @socket: a #GSocket.
* @group: a #GInetAddress specifying the group address to join.
* @source_specific: (nullable): a #GInetAddress specifying the
* source-specific multicast address or %NULL to ignore.
* @iface: (nullable): Name of the interface to use, or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Registers @socket to receive multicast messages sent to @group.
* @socket must be a %G_SOCKET_TYPE_DATAGRAM socket, and must have
* been bound to an appropriate interface and port with
* g_socket_bind().
*
* If @iface is %NULL, the system will automatically pick an interface
* to bind to based on @group.
*
* If @source_specific is not %NULL, use source-specific multicast as
* defined in RFC 4604. Note that on older platforms this may fail
* with a %G_IO_ERROR_NOT_SUPPORTED error.
*
* Note that this function can be called multiple times for the same
* @group with different @source_specific in order to receive multicast
* packets from more than one source.
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.56
*/
gboolean
g_socket_join_multicast_group_ssm (GSocket *socket,
GInetAddress *group,
GInetAddress *source_specific,
const gchar *iface,
GError **error)
{
return g_socket_multicast_group_operation_ssm (socket, group,
source_specific, iface, TRUE, error);
}
/**
* g_socket_leave_multicast_group_ssm:
* @socket: a #GSocket.
* @group: a #GInetAddress specifying the group address to leave.
* @source_specific: (nullable): a #GInetAddress specifying the
* source-specific multicast address or %NULL to ignore.
* @iface: (nullable): Name of the interface to use, or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Removes @socket from the multicast group defined by @group, @iface,
* and @source_specific (which must all have the same values they had
* when you joined the group).
*
* @socket remains bound to its address and port, and can still receive
* unicast messages after calling this.
*
* Returns: %TRUE on success, %FALSE on error.
*
* Since: 2.56
*/
gboolean
g_socket_leave_multicast_group_ssm (GSocket *socket,
GInetAddress *group,
GInetAddress *source_specific,
const gchar *iface,
GError **error)
{
return g_socket_multicast_group_operation_ssm (socket, group,
source_specific, iface, FALSE, error);
}
/**
* g_socket_speaks_ipv4:
* @socket: a #GSocket
*
* Checks if a socket is capable of speaking IPv4.
*
* IPv4 sockets are capable of speaking IPv4. On some operating systems
* and under some combinations of circumstances IPv6 sockets are also
* capable of speaking IPv4. See RFC 3493 section 3.7 for more
* information.
*
* No other types of sockets are currently considered as being capable
* of speaking IPv4.
*
* Returns: %TRUE if this socket can be used with IPv4.
*
* Since: 2.22
**/
gboolean
g_socket_speaks_ipv4 (GSocket *socket)
{
switch (socket->priv->family)
{
case G_SOCKET_FAMILY_IPV4:
return TRUE;
case G_SOCKET_FAMILY_IPV6:
#if defined (IPPROTO_IPV6) && defined (IPV6_V6ONLY)
{
gint v6_only;
if (!g_socket_get_option (socket,
IPPROTO_IPV6, IPV6_V6ONLY,
&v6_only, NULL))
return FALSE;
return !v6_only;
}
#else
return FALSE;
#endif
default:
return FALSE;
}
}
/**
* g_socket_accept:
* @socket: a #GSocket.
* @cancellable: (nullable): a %GCancellable or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Accept incoming connections on a connection-based socket. This removes
* the first outstanding connection request from the listening socket and
* creates a #GSocket object for it.
*
* The @socket must be bound to a local address with g_socket_bind() and
* must be listening for incoming connections (g_socket_listen()).
*
* If there are no outstanding connections then the operation will block
* or return %G_IO_ERROR_WOULD_BLOCK if non-blocking I/O is enabled.
* To be notified of an incoming connection, wait for the %G_IO_IN condition.
*
* Returns: (transfer full): a new #GSocket, or %NULL on error.
* Free the returned object with g_object_unref().
*
* Since: 2.22
*/
GSocket *
g_socket_accept (GSocket *socket,
GCancellable *cancellable,
GError **error)
{
#ifdef HAVE_ACCEPT4
gboolean try_accept4 = TRUE;
#endif
GSocket *new_socket;
gint ret;
g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
if (!check_socket (socket, error))
return NULL;
if (!check_timeout (socket, error))
return NULL;
while (TRUE)
{
gboolean try_accept = TRUE;
#ifdef HAVE_ACCEPT4
if (try_accept4)
{
ret = accept4 (socket->priv->fd, NULL, 0, SOCK_CLOEXEC);
if (ret < 0 && errno == ENOSYS)
{
try_accept4 = FALSE;
}
else
{
try_accept = FALSE;
}
}
g_assert (try_accept4 || try_accept);
#endif
if (try_accept)
ret = accept (socket->priv->fd, NULL, 0);
if (ret < 0)
{
int errsv = get_socket_errno ();
if (errsv == EINTR)
continue;
#ifdef WSAEWOULDBLOCK
if (errsv == WSAEWOULDBLOCK)
#else
if (errsv == EWOULDBLOCK ||
errsv == EAGAIN)
#endif
{
win32_unset_event_mask (socket, FD_ACCEPT);
if (socket->priv->blocking)
{
if (!g_socket_condition_wait (socket,
G_IO_IN, cancellable, error))
return NULL;
continue;
}
}
socket_set_error_lazy (error, errsv, _("Error accepting connection: %s"));
return NULL;
}
break;
}
win32_unset_event_mask (socket, FD_ACCEPT);
#ifdef G_OS_WIN32
{
/* The socket inherits the accepting sockets event mask and even object,
we need to remove that */
WSAEventSelect (ret, NULL, 0);
}
#else
{
int flags;
/* We always want to set close-on-exec to protect users. If you
need to so some weird inheritance to exec you can re-enable this
using lower level hacks with g_socket_get_fd(). */
flags = fcntl (ret, F_GETFD, 0);
if (flags != -1 &&
(flags & FD_CLOEXEC) == 0)
{
flags |= FD_CLOEXEC;
fcntl (ret, F_SETFD, flags);
}
}
#endif
new_socket = g_socket_new_from_fd (ret, error);
if (new_socket == NULL)
{
#ifdef G_OS_WIN32
closesocket (ret);
#else
close (ret);
#endif
}
else
new_socket->priv->protocol = socket->priv->protocol;
return new_socket;
}
/**
* g_socket_connect:
* @socket: a #GSocket.
* @address: a #GSocketAddress specifying the remote address.
* @cancellable: (nullable): a %GCancellable or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Connect the socket to the specified remote address.
*
* For connection oriented socket this generally means we attempt to make
* a connection to the @address. For a connection-less socket it sets
* the default address for g_socket_send() and discards all incoming datagrams
* from other sources.
*
* Generally connection oriented sockets can only connect once, but
* connection-less sockets can connect multiple times to change the
* default address.
*
* If the connect call needs to do network I/O it will block, unless
* non-blocking I/O is enabled. Then %G_IO_ERROR_PENDING is returned
* and the user can be notified of the connection finishing by waiting
* for the G_IO_OUT condition. The result of the connection must then be
* checked with g_socket_check_connect_result().
*
* Returns: %TRUE if connected, %FALSE on error.
*
* Since: 2.22
*/
gboolean
g_socket_connect (GSocket *socket,
GSocketAddress *address,
GCancellable *cancellable,
GError **error)
{
union {
struct sockaddr_storage storage;
struct sockaddr sa;
} buffer;
g_return_val_if_fail (G_IS_SOCKET (socket) && G_IS_SOCKET_ADDRESS (address), FALSE);
if (!check_socket (socket, error))
return FALSE;
if (!g_socket_address_to_native (address, &buffer.storage, sizeof buffer, error))
return FALSE;
if (socket->priv->remote_address)
g_object_unref (socket->priv->remote_address);
socket->priv->remote_address = g_object_ref (address);
while (1)
{
if (connect (socket->priv->fd, &buffer.sa,
g_socket_address_get_native_size (address)) < 0)
{
int errsv = get_socket_errno ();
if (errsv == EINTR)
continue;
#ifndef G_OS_WIN32
if (errsv == EINPROGRESS)
#else
if (errsv == WSAEWOULDBLOCK)
#endif
{
win32_unset_event_mask (socket, FD_CONNECT);
if (socket->priv->blocking)
{
if (g_socket_condition_wait (socket, G_IO_OUT, cancellable, error))
{
if (g_socket_check_connect_result (socket, error))
break;
}
}
else
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
_("Connection in progress"));
socket->priv->connect_pending = TRUE;
}
}
else
g_set_error_literal (error, G_IO_ERROR,
socket_io_error_from_errno (errsv),
socket_strerror (errsv));
return FALSE;
}
break;
}
win32_unset_event_mask (socket, FD_CONNECT);
socket->priv->connected_read = TRUE;
socket->priv->connected_write = TRUE;
return TRUE;
}
/**
* g_socket_check_connect_result:
* @socket: a #GSocket
* @error: #GError for error reporting, or %NULL to ignore.
*
* Checks and resets the pending connect error for the socket.
* This is used to check for errors when g_socket_connect() is
* used in non-blocking mode.
*
* Returns: %TRUE if no error, %FALSE otherwise, setting @error to the error
*
* Since: 2.22
*/
gboolean
g_socket_check_connect_result (GSocket *socket,
GError **error)
{
int value;
g_return_val_if_fail (G_IS_SOCKET (socket), FALSE);
if (!check_socket (socket, error))
return FALSE;
if (!check_timeout (socket, error))
return FALSE;
if (!g_socket_get_option (socket, SOL_SOCKET, SO_ERROR, &value, error))
{
g_prefix_error (error, _("Unable to get pending error: "));
return FALSE;
}
if (value != 0)
{
g_set_error_literal (error, G_IO_ERROR, socket_io_error_from_errno (value),
socket_strerror (value));
if (socket->priv->remote_address)
{
g_object_unref (socket->priv->remote_address);
socket->priv->remote_address = NULL;
}
return FALSE;
}
socket->priv->connected_read = TRUE;
socket->priv->connected_write = TRUE;
return TRUE;
}
/**
* g_socket_get_available_bytes:
* @socket: a #GSocket
*
* Get the amount of data pending in the OS input buffer, without blocking.
*
* If @socket is a UDP or SCTP socket, this will return the size of
* just the next packet, even if additional packets are buffered after
* that one.
*
* Note that on Windows, this function is rather inefficient in the
* UDP case, and so if you know any plausible upper bound on the size
* of the incoming packet, it is better to just do a
* g_socket_receive() with a buffer of that size, rather than calling
* g_socket_get_available_bytes() first and then doing a receive of
* exactly the right size.
*
* Returns: the number of bytes that can be read from the socket
* without blocking or truncating, or -1 on error.
*
* Since: 2.32
*/
gssize
g_socket_get_available_bytes (GSocket *socket)
{
#ifndef SO_NREAD
const gint bufsize = 64 * 1024;
static guchar *buf = NULL;
#endif
#ifdef G_OS_WIN32
u_long avail;
#else
gint avail;
#endif
g_return_val_if_fail (G_IS_SOCKET (socket), -1);
if (!check_socket (socket, NULL))
return -1;
#ifdef SO_NREAD
if (!g_socket_get_option (socket, SOL_SOCKET, SO_NREAD, &avail, NULL))
return -1;
#else
if (socket->priv->type == G_SOCKET_TYPE_DATAGRAM)
{
if (G_UNLIKELY (g_once_init_enter_pointer (&buf)))
g_once_init_leave_pointer (&buf, g_malloc (bufsize));
/* On datagram sockets, FIONREAD ioctl is not reliable because many
* systems add internal header size to the reported size, making it
* unusable for this function. */
avail = recv (socket->priv->fd, buf, bufsize, MSG_PEEK);
if ((gint) avail == -1)
{
int errsv = get_socket_errno ();
#ifdef G_OS_WIN32
if (errsv == WSAEWOULDBLOCK)
#else
if (errsv == EWOULDBLOCK || errsv == EAGAIN)
#endif
avail = 0;
}
}
else
{
#ifdef G_OS_WIN32
if (ioctlsocket (socket->priv->fd, FIONREAD, &avail) < 0)
#else
if (ioctl (socket->priv->fd, FIONREAD, &avail) < 0)
#endif
avail = -1;
}
#endif
return avail;
}
/* Block on a timed wait for @condition until (@start_time + @timeout).
* Return %G_IO_ERROR_TIMED_OUT if the timeout is reached; otherwise %TRUE.
*/
static gboolean
block_on_timeout (GSocket *socket,
GIOCondition condition,
gint64 timeout_us,
gint64 start_time,
GCancellable *cancellable,
GError **error)
{
gint64 wait_timeout = -1;
g_return_val_if_fail (timeout_us != 0, TRUE);
/* check if we've timed out or how much time to wait at most */
if (timeout_us >= 0)
{
gint64 elapsed = g_get_monotonic_time () - start_time;
if (elapsed >= timeout_us)
{
g_set_error_literal (error,
G_IO_ERROR, G_IO_ERROR_TIMED_OUT,
_("Socket I/O timed out"));
return FALSE;
}
wait_timeout = timeout_us - elapsed;
}
return g_socket_condition_timed_wait (socket, condition, wait_timeout,
cancellable, error);
}
static gssize
g_socket_receive_with_timeout (GSocket *socket,
guint8 *buffer,
gsize size,
gint64 timeout_us,
GCancellable *cancellable,
GError **error)
{
gssize ret;
gint64 start_time;
g_return_val_if_fail (G_IS_SOCKET (socket) && buffer != NULL, -1);
start_time = g_get_monotonic_time ();
if (!check_socket (socket, error))
return -1;
if (!check_timeout (socket, error))
return -1;
if (g_cancellable_set_error_if_cancelled (cancellable, error))
return -1;
while (1)
{
if ((ret = recv (socket->priv->fd, buffer, size, 0)) < 0)
{
int errsv = get_socket_errno ();
if (errsv == EINTR)
continue;
#ifdef WSAEWOULDBLOCK
if (errsv == WSAEWOULDBLOCK)
#else
if (errsv == EWOULDBLOCK ||
errsv == EAGAIN)
#endif
{
win32_unset_event_mask (socket, FD_READ);
if (timeout_us != 0)
{
if (!block_on_timeout (socket, G_IO_IN, timeout_us, start_time,
cancellable, error))
return -1;
continue;
}
}
win32_unset_event_mask (socket, FD_READ);
socket_set_error_lazy (error, errsv, _("Error receiving data: %s"));
return -1;
}
win32_unset_event_mask (socket, FD_READ);
break;
}
return ret;
}
/**
* g_socket_receive_bytes:
* @socket: a #GSocket
* @size: the number of bytes you want to read from the socket
* @timeout_us: the timeout to wait for, in microseconds, or `-1` to block
* indefinitely
* @cancellable: (nullable): a %GCancellable, or `NULL`
* @error: return location for a #GError, or `NULL`
*
* Receives data (up to @size bytes) from a socket.
*
* This function is a variant of [method@Gio.Socket.receive] which returns a
* [struct@GLib.Bytes] rather than a plain buffer.
*
* Pass `-1` to @timeout_us to block indefinitely until data is received (or
* the connection is closed, or there is an error). Pass `0` to use the default
* timeout from [property@Gio.Socket:timeout], or pass a positive number to wait
* for that many microseconds for data before returning `G_IO_ERROR_TIMED_OUT`.
*
* Returns: (transfer full): a bytes buffer containing the
* received bytes, or `NULL` on error
* Since: 2.80
*/
GBytes *
g_socket_receive_bytes (GSocket *socket,
gsize size,
gint64 timeout_us,
GCancellable *cancellable,
GError **error)
{
guint8 *data;
gssize res;
GBytes *buf;
g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
data = g_new0 (guint8, size);
res = g_socket_receive_with_timeout (socket, data, size, timeout_us, cancellable, error);
if (res < 0)
{
g_free (data);
return NULL;
}
if ((gsize) res == size)
{
buf = g_bytes_new_take (g_steal_pointer (&data), (gsize) res);
}
else
{
GBytes *sub_buf;
buf = g_bytes_new_take (g_steal_pointer (&data), size);
sub_buf = g_bytes_new_from_bytes (buf, 0, (gsize) res);
g_bytes_unref (buf);
buf = g_steal_pointer (&sub_buf);
}
return g_steal_pointer (&buf);
}
/**
* g_socket_receive:
* @socket: a #GSocket
* @buffer: (array length=size) (element-type guint8) (out caller-allocates):
* a buffer to read data into (which should be at least @size bytes long).
* @size: (in): the number of bytes you want to read from the socket
* @cancellable: (nullable): a %GCancellable or %NULL
* @error: #GError for error reporting, or %NULL to ignore.
*
* Receive data (up to @size bytes) from a socket. This is mainly used by
* connection-oriented sockets; it is identical to g_socket_receive_from()
* with @address set to %NULL.
*
* For %G_SOCKET_TYPE_DATAGRAM and %G_SOCKET_TYPE_SEQPACKET sockets,
* g_socket_receive() will always read either 0 or 1 complete messages from
* the socket. If the received message is too large to fit in @buffer, then
* the data beyond @size bytes will be discarded, without any explicit
* indication that this has occurred.
*
* For %G_SOCKET_TYPE_STREAM sockets, g_socket_receive() can return any
* number of bytes, up to @size. If more than @size bytes have been
* received, the additional data will be returned in future calls to
* g_socket_receive().
*
* If the socket is in blocking mode the call will block until there
* is some data to receive, the connection is closed, or there is an
* error. If there is no data available and the socket is in
* non-blocking mode, a %G_IO_ERROR_WOULD_BLOCK error will be
* returned. To be notified when data is available, wait for the
* %G_IO_IN condition.
*
* On error -1 is returned and @error is set accordingly.
*
* Returns: Number of bytes read, or 0 if the connection was closed b