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>
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index fbce4a3..98d1f0b 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1633,7 +1633,8 @@
{
struct sock *sk = sock->sk;
struct iucv_sock *iucv = iucv_sk(sk);
- int val, len;
+ unsigned int val;
+ int len;
if (level != SOL_IUCV)
return -ENOPROTOOPT;
@@ -1656,6 +1657,13 @@
: iucv->msglimit; /* default */
release_sock(sk);
break;
+ case SO_MSGSIZE:
+ if (sk->sk_state == IUCV_OPEN)
+ return -EBADFD;
+ val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
+ sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
+ 0x7fffffff;
+ break;
default:
return -ENOPROTOOPT;
}