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>
This commit is contained in:
Ursula Braun 2012-02-08 00:19:48 +00:00 committed by David S. Miller
parent 800c5eb7b5
commit 51363b8751
2 changed files with 10 additions and 1 deletions

View File

@ -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 */

View File

@ -1633,7 +1633,8 @@ static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
{
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 @@ static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
: 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;
}