net/rds Add getsockopt support for SO_RDS_TRANSPORT
The currently attached transport for a PF_RDS socket may be obtained
from user space by invoking getsockopt(2) using the SO_RDS_TRANSPORT
option at the SOL_RDS level. The integer optval returned will be one
of the RDS_TRANS_* constants defined in linux/rds.h.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index 0487744..2ad9032 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -339,6 +339,7 @@
{
struct rds_sock *rs = rds_sk_to_rs(sock->sk);
int ret = -ENOPROTOOPT, len;
+ int trans;
if (level != SOL_RDS)
goto out;
@@ -364,6 +365,19 @@
else
ret = 0;
break;
+ case SO_RDS_TRANSPORT:
+ if (len < sizeof(int)) {
+ ret = -EINVAL;
+ break;
+ }
+ trans = (rs->rs_transport ? rs->rs_transport->t_type :
+ RDS_TRANS_NONE); /* unbound */
+ if (put_user(trans, (int __user *)optval) ||
+ put_user(sizeof(int), optlen))
+ ret = -EFAULT;
+ else
+ ret = 0;
+ break;
default:
break;
}