[NET]: allow 32 bit socket ioctl in 64 bit kernel

Since the register_ioctl32_conversion() patch in the kernel is now obsolete,
provide another method to allow 32 bit user space ioctls to reach the kernel.
Signed-off-by: Shaun Pereira <spereira@tusc.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/net.h

@@ -143,6 +143,8 @@ struct proto_ops {
 				      struct poll_table_struct *wait);
 	int		(*ioctl)     (struct socket *sock, unsigned int cmd,
 				      unsigned long arg);
+	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
+				      unsigned long arg);
 	int		(*listen)    (struct socket *sock, int len);
 	int		(*shutdown)  (struct socket *sock, int flags);
 	int		(*setsockopt)(struct socket *sock, int level,
@@ -251,6 +253,8 @@ SOCKCALL_UWRAP(name, poll, (struct file *file, struct socket *sock, struct poll_
 	      (file, sock, wait)) \
 SOCKCALL_WRAP(name, ioctl, (struct socket *sock, unsigned int cmd, \
 			 unsigned long arg), (sock, cmd, arg)) \
+SOCKCALL_WRAP(name, compat_ioctl, (struct socket *sock, unsigned int cmd, \
+			 unsigned long arg), (sock, cmd, arg)) \
 SOCKCALL_WRAP(name, listen, (struct socket *sock, int len), (sock, len)) \
 SOCKCALL_WRAP(name, shutdown, (struct socket *sock, int flags), (sock, flags)) \
 SOCKCALL_WRAP(name, setsockopt, (struct socket *sock, int level, int optname, \
@@ -275,6 +279,7 @@ static const struct proto_ops name##_ops = {			\
 	.getname	= __lock_##name##_getname,	\
 	.poll		= __lock_##name##_poll,		\
 	.ioctl		= __lock_##name##_ioctl,	\
+	.compat_ioctl	= __lock_##name##_compat_ioctl,	\
 	.listen		= __lock_##name##_listen,	\
 	.shutdown	= __lock_##name##_shutdown,	\
 	.setsockopt	= __lock_##name##_setsockopt,	\
@@ -283,6 +288,7 @@ static const struct proto_ops name##_ops = {			\
 	.recvmsg	= __lock_##name##_recvmsg,	\
 	.mmap		= __lock_##name##_mmap,		\
 };
+
 #endif
 
 #define MODULE_ALIAS_NETPROTO(proto) \

net/socket.c

@@ -107,6 +107,10 @@ static unsigned int sock_poll(struct file *file,
 			      struct poll_table_struct *wait);
 static long sock_ioctl(struct file *file,
 		      unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long compat_sock_ioctl(struct file *file,
+		      unsigned int cmd, unsigned long arg);
+#endif
 static int sock_fasync(int fd, struct file *filp, int on);
 static ssize_t sock_readv(struct file *file, const struct iovec *vector,
 			  unsigned long count, loff_t *ppos);
@@ -128,6 +132,9 @@ static struct file_operations socket_file_ops = {
 	.aio_write =	sock_aio_write,
 	.poll =		sock_poll,
 	.unlocked_ioctl = sock_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = compat_sock_ioctl,
+#endif
 	.mmap =		sock_mmap,
 	.open =		sock_no_open,	/* special open code to disallow open via /proc */
 	.release =	sock_close,
@@ -2136,6 +2143,20 @@ void socket_seq_show(struct seq_file *seq)
 }
 #endif /* CONFIG_PROC_FS */
 
+#ifdef CONFIG_COMPAT
+static long compat_sock_ioctl(struct file *file, unsigned cmd,
+				unsigned long arg)
+{
+	struct socket *sock = file->private_data;
+	int ret = -ENOIOCTLCMD;
+
+	if (sock->ops->compat_ioctl)
+		ret = sock->ops->compat_ioctl(sock, cmd, arg);
+
+	return ret;
+}
+#endif
+
 /* ABI emulation layers need these two */
 EXPORT_SYMBOL(move_addr_to_kernel);
 EXPORT_SYMBOL(move_addr_to_user);