af_iucv: allow retrieval of maximum message size

For HS transport the maximum message size depends on the MTU-size
of the HS-device bound to the AF_IUCV socket. This patch adds a
getsockopt option MSGSIZE returning the maximum message size that
can be handled for this AF_IUCV socket.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
index a1517887aeac..2e1d5ecc2d1b 100644
--- a/include/net/iucv/af_iucv.h
+++ b/include/net/iucv/af_iucv.h
@@ -132,6 +132,7 @@ struct iucv_sock {
 /* iucv socket options (SOL_IUCV) */
 #define SO_IPRMDATA_MSG 0x0080          /* send/recv IPRM_DATA msgs */
 #define SO_MSGLIMIT     0x1000          /* get/set IUCV MSGLIMIT */
+#define SO_MSGSIZE      0x0800          /* get maximum msgsize */
 
 /* iucv related control messages (scm) */
 #define SCM_IUCV_TRGCLS 0x0001          /* target class control message */