diff --git a/include/uapi/linux/rds.h b/include/uapi/linux/rds.h
index 9195095..0f9265c 100644
--- a/include/uapi/linux/rds.h
+++ b/include/uapi/linux/rds.h
@@ -38,6 +38,8 @@
 
 #define RDS_IB_ABI_VERSION		0x301
 
+#define	SOL_RDS		276
+
 /*
  * setsockopt/getsockopt for SOL_RDS
  */
@@ -48,6 +50,14 @@
 #define RDS_RECVERR			5
 #define RDS_CONG_MONITOR		6
 #define RDS_GET_MR_FOR_DEST		7
+#define SO_RDS_TRANSPORT		8
+
+/* supported values for SO_RDS_TRANSPORT */
+#define	RDS_TRANS_IB	0
+#define	RDS_TRANS_IWARP	1
+#define	RDS_TRANS_TCP	2
+#define RDS_TRANS_COUNT	3
+#define	RDS_TRANS_NONE	(~0)
 
 /*
  * Control message types for SOL_RDS.
diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index 3d83641..2ad9032 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -270,6 +270,28 @@
 	return ret;
 }
 
+static int rds_set_transport(struct rds_sock *rs, char __user *optval,
+			     int optlen)
+{
+	int t_type;
+
+	if (rs->rs_transport)
+		return -EOPNOTSUPP; /* previously attached to transport */
+
+	if (optlen != sizeof(int))
+		return -EINVAL;
+
+	if (copy_from_user(&t_type, (int __user *)optval, sizeof(t_type)))
+		return -EFAULT;
+
+	if (t_type < 0 || t_type >= RDS_TRANS_COUNT)
+		return -EINVAL;
+
+	rs->rs_transport = rds_trans_get(t_type);
+
+	return rs->rs_transport ? 0 : -ENOPROTOOPT;
+}
+
 static int rds_setsockopt(struct socket *sock, int level, int optname,
 			  char __user *optval, unsigned int optlen)
 {
@@ -300,6 +322,11 @@
 	case RDS_CONG_MONITOR:
 		ret = rds_cong_monitor(rs, optval, optlen);
 		break;
+	case SO_RDS_TRANSPORT:
+		lock_sock(sock->sk);
+		ret = rds_set_transport(rs, optval, optlen);
+		release_sock(sock->sk);
+		break;
 	default:
 		ret = -ENOPROTOOPT;
 	}
@@ -312,6 +339,7 @@
 {
 	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 	int ret = -ENOPROTOOPT, len;
+	int trans;
 
 	if (level != SOL_RDS)
 		goto out;
@@ -337,6 +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;
 	}
diff --git a/net/rds/bind.c b/net/rds/bind.c
index a2e6562..4ebd29c 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -181,6 +181,10 @@
 	if (ret)
 		goto out;
 
+	if (rs->rs_transport) { /* previously bound */
+		ret = 0;
+		goto out;
+	}
 	trans = rds_trans_get_preferred(sin->sin_addr.s_addr);
 	if (!trans) {
 		ret = -EADDRNOTAVAIL;
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 0d41155..a33fb4a 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -408,11 +408,6 @@
  *                 should try hard not to block.
  */
 
-#define RDS_TRANS_IB	0
-#define RDS_TRANS_IWARP	1
-#define RDS_TRANS_TCP	2
-#define RDS_TRANS_COUNT	3
-
 struct rds_transport {
 	char			t_name[TRANSNAMSIZ];
 	struct list_head	t_item;
@@ -803,6 +798,7 @@
 void rds_trans_put(struct rds_transport *trans);
 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
 				       unsigned int avail);
+struct rds_transport *rds_trans_get(int t_type);
 int rds_trans_init(void);
 void rds_trans_exit(void);
 
diff --git a/net/rds/transport.c b/net/rds/transport.c
index 7f2ac4f..8b4a6cd 100644
--- a/net/rds/transport.c
+++ b/net/rds/transport.c
@@ -101,6 +101,27 @@
 	return ret;
 }
 
+struct rds_transport *rds_trans_get(int t_type)
+{
+	struct rds_transport *ret = NULL;
+	struct rds_transport *trans;
+	unsigned int i;
+
+	down_read(&rds_trans_sem);
+	for (i = 0; i < RDS_TRANS_COUNT; i++) {
+		trans = transports[i];
+
+		if (trans && trans->t_type == t_type &&
+		    (!trans->t_owner || try_module_get(trans->t_owner))) {
+			ret = trans;
+			break;
+		}
+	}
+	up_read(&rds_trans_sem);
+
+	return ret;
+}
+
 /*
  * This returns the number of stats entries in the snapshot and only
  * copies them using the iter if there is enough space for them.  The