Commit 293c103a authored by Ting-Wei Lan's avatar Ting-Wei Lan

socket: Fix get_available_bytes on systems other than Linux and Windows

FIONREAD ioctl on Linux reports the size of payload on UDP sockets.
However, other systems usually add internal header size to the reported
size, which vary between different operating systems and socket types.
To make it work on more systems, we should follow what we do on Windows
instead of using this unreliable FIONREAD ioctl.

This fixes socket test on FreeBSD.
parent b4259dec
......@@ -2957,9 +2957,11 @@ g_socket_check_connect_result (GSocket *socket,
gssize
g_socket_get_available_bytes (GSocket *socket)
{
#ifdef G_OS_WIN32
#ifndef SO_NREAD
const gint bufsize = 64 * 1024;
static guchar *buf = NULL;
#endif
#ifdef G_OS_WIN32
u_long avail;
#else
gint avail;
......@@ -2967,25 +2969,37 @@ g_socket_get_available_bytes (GSocket *socket)
g_return_val_if_fail (G_IS_SOCKET (socket), -1);
#if defined (SO_NREAD)
#ifdef SO_NREAD
if (!g_socket_get_option (socket, SOL_SOCKET, SO_NREAD, &avail, NULL))
return -1;
#elif !defined (G_OS_WIN32)
if (ioctl (socket->priv->fd, FIONREAD, &avail) < 0)
avail = -1;
#else
if (socket->priv->type == G_SOCKET_TYPE_DATAGRAM)
{
if (G_UNLIKELY (g_once_init_enter (&buf)))
g_once_init_leave (&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 (avail == -1 && get_socket_errno () == WSAEWOULDBLOCK)
avail = 0;
if (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
......
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