iscsi_tcp: export port being used

This just has iscsi_tcp support ISCSI_PARAM_LOCAL_PORT which
exports the local port being used by the iscsi connection.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/iscsi_tcp.c

@@ -726,13 +726,18 @@ static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn,
 	switch(param) {
 	case ISCSI_PARAM_CONN_PORT:
 	case ISCSI_PARAM_CONN_ADDRESS:
+	case ISCSI_PARAM_LOCAL_PORT:
 		spin_lock_bh(&conn->session->frwd_lock);
 		if (!tcp_sw_conn || !tcp_sw_conn->sock) {
 			spin_unlock_bh(&conn->session->frwd_lock);
 			return -ENOTCONN;
 		}
-		rc = kernel_getpeername(tcp_sw_conn->sock,
-					(struct sockaddr *)&addr, &len);
+		if (param == ISCSI_PARAM_LOCAL_PORT)
+			rc = kernel_getsockname(tcp_sw_conn->sock,
+						(struct sockaddr *)&addr, &len);
+		else
+			rc = kernel_getpeername(tcp_sw_conn->sock,
+						(struct sockaddr *)&addr, &len);
 		spin_unlock_bh(&conn->session->frwd_lock);
 		if (rc)
 			return rc;
@@ -895,6 +900,7 @@ static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param)
 		case ISCSI_PARAM_DATADGST_EN:
 		case ISCSI_PARAM_CONN_ADDRESS:
 		case ISCSI_PARAM_CONN_PORT:
+		case ISCSI_PARAM_LOCAL_PORT:
 		case ISCSI_PARAM_EXP_STATSN:
 		case ISCSI_PARAM_PERSISTENT_ADDRESS:
 		case ISCSI_PARAM_PERSISTENT_PORT:

drivers/scsi/libiscsi.c

@@ -3505,6 +3505,7 @@ int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
 		break;
 	case ISCSI_PARAM_CONN_PORT:
+	case ISCSI_PARAM_LOCAL_PORT:
 		if (sin)
 			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
 		else