Re: [PATCH openvswitch v2] netlink: Implement & enable memory mapped netlink i/o

[Ben Pfaff <blp@nicira.com>]

On Mon, Dec 02, 2013 at 11:16:31PM +0100, Thomas Graf wrote:
> >GCC reports:
> >
> >     ../lib/netlink-socket.c: In function 'nl_sock_send_mmap':
> >     ../lib/netlink-socket.c:369:5: error: implicit declaration of function '__ALIGN_KERNEL' [-Werror=implicit-function-declaration]
> >     cc1: all warnings being treated as errors
> 
> Just so we can simplify this process: what's the oldest environment you
> want the code to compile on?

FreeBSD.

This is not a Linux-specific header, it is included on all platforms.
As the comment at the top says:

/* Netlink protocol definitions.
 *
 * Netlink is a message framing format described in RFC 3549 and used heavily
 * in Linux to access the network stack.  Open vSwitch uses AF_NETLINK sockets
 * for this purpose on Linux.  But on all platforms, Open vSwitch uses Netlink
 * message framing internally for certain purposes.
 *
 * This header provides access to the Netlink message framing definitions
 * regardless of platform.  On Linux, it includes the proper headers directly;
 * on other platforms it directly defines the structures and macros itself.
 */