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/m32r/include/asm/socket.h b/arch/m32r/include/asm/socket.h
index d36f5928fb79..3390a864f224 100644
--- a/arch/m32r/include/asm/socket.h
+++ b/arch/m32r/include/asm/socket.h
@@ -58,5 +58,6 @@
 #define SCM_TIMESTAMPING        SO_TIMESTAMPING
 
 #define SO_PROTOCOL             38
+#define SO_DOMAIN               39
 
 #endif /* _ASM_M32R_SOCKET_H */