net: implement a SO_DOMAIN getsockoption

This sockopt goes in line with SO_TYPE and SO_PROTOCOL. It makes it
possible for userspace programs to pass around file descriptors — I
am referring to arguments-to-functions, but it may even work for the
fd passing over UNIX sockets — without needing to also pass the
auxiliary information (PF_INET6/IPPROTO_TCP).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/alpha/include/asm/socket.h b/arch/alpha/include/asm/socket.h
index 2f8b4d377749..26773e3246e2 100644
--- a/arch/alpha/include/asm/socket.h
+++ b/arch/alpha/include/asm/socket.h
@@ -33,6 +33,7 @@
 #define SO_SNDTIMEO     0x1013
 #define SO_ACCEPTCONN   0x1014
 #define SO_PROTOCOL     0x1028
+#define SO_DOMAIN       0x1029
 
 /* linux-specific, might as well be the same as on i386 */
 #define SO_NO_CHECK     11