gsocket: Work around broken CMSG_FIRSTHDR()

As RFC 2292 points out, some platforms (e.g. Darwin 9.8.0) provide
CMSG_FIRSTHDR(msg) which just returns msg.msg_control without first
checking if msg.msg_controllen is non-zero. We need a workaround for
such platforms not to let g_socket_receive_message() segfault.

https://bugzilla.gnome.org/show_bug.cgi?id=690388
This commit is contained in:
PHO 2012-12-18 08:33:50 +09:00 committed by Dan Winship
parent 780871d273
commit f0f6c8d231

View File

@ -4154,33 +4154,36 @@ g_socket_receive_message (GSocket *socket,
GPtrArray *my_messages = NULL;
struct cmsghdr *cmsg;
for (cmsg = CMSG_FIRSTHDR (&msg); cmsg; cmsg = CMSG_NXTHDR (&msg, cmsg))
{
GSocketControlMessage *message;
if (msg.msg_controllen >= sizeof (struct cmsghdr))
{
for (cmsg = CMSG_FIRSTHDR (&msg); cmsg; cmsg = CMSG_NXTHDR (&msg, cmsg))
{
GSocketControlMessage *message;
message = g_socket_control_message_deserialize (cmsg->cmsg_level,
cmsg->cmsg_type,
cmsg->cmsg_len - ((char *)CMSG_DATA (cmsg) - (char *)cmsg),
CMSG_DATA (cmsg));
if (message == NULL)
/* We've already spewed about the problem in the
deserialization code, so just continue */
continue;
message = g_socket_control_message_deserialize (cmsg->cmsg_level,
cmsg->cmsg_type,
cmsg->cmsg_len - ((char *)CMSG_DATA (cmsg) - (char *)cmsg),
CMSG_DATA (cmsg));
if (message == NULL)
/* We've already spewed about the problem in the
deserialization code, so just continue */
continue;
if (messages == NULL)
{
/* we have to do it this way if the user ignores the
* messages so that we will close any received fds.
*/
g_object_unref (message);
}
else
{
if (my_messages == NULL)
my_messages = g_ptr_array_new ();
g_ptr_array_add (my_messages, message);
}
}
if (messages == NULL)
{
/* we have to do it this way if the user ignores the
* messages so that we will close any received fds.
*/
g_object_unref (message);
}
else
{
if (my_messages == NULL)
my_messages = g_ptr_array_new ();
g_ptr_array_add (my_messages, message);
}
}
}
if (num_messages)
*num_messages = my_messages != NULL ? my_messages->len : 0;