Re: [PATCH net-next v2 05/10] headers, net: Define struct __kernel_sockaddr, replacing struct sockaddr

On Fri, Aug 26, 2011 at 11:08:20AM -0400, David Miller wrote:

From: Ben Hutchings <redacted>
Date: Thu, 25 Aug 2011 05:44:15 +0100

quoted

Commit 9c501935a3cdcf6b1d35aaee3aa11c7a7051a305 ('net: Support
inclusion of <linux/socket.h> before <sys/socket.h>') removed the
definition of struct sockaddr for userland.

But we still have several headers using struct sockaddr, and we
shouldn't make them include <sys/socket.h> as that risks recursive
inclusion in future.  Define and use an identical struct
__kernel_sockaddr instead.

Signed-off-by: Ben Hutchings <redacted>

 ...

quoted

 
-/*
- *	1003.1g requires sa_family_t and that sa_data is char.
- */
+#define sockaddr __kernel_sockaddr

This cure is worse than the disease.

Now any application that includes sys/socket.h one way or another is
now going to get a real hard build failure since __kernel_sockaddr
will effectively get redefined.

[...]
 
This #define is in the #ifdef __KERNEL__ section.  I don't want t
change all the in-kernel users to say __kernel_sockaddr.  This is
just the same as the preceding 'typedef __kernel_sa_family_t
sa_family_t' except that you can't create struct aliases that way.

Ben.

-- 
Ben Hutchings
We get into the habit of living before acquiring the habit of thinking.
                                                              - Albert Camus