RDMA/core: Fix corrupted SL on passive side

On RoCE systems, a CM REQ contains a Primary Hop Limit > 1 and Primary
Subnet Local is zero.

In cm_req_handler(), the cm_process_routed_req() function is called. Since
the Primary Subnet Local value is zero in the request, and since this is
RoCE (Primary Local LID is permissive), the following statement will be
executed:

      IBA_SET(CM_REQ_PRIMARY_SL, req_msg, wc->sl);

This corrupts SL in req_msg if it was different from zero. In other words,
a request to setup a connection using an SL != zero, will not be honored,
and a connection using SL zero will be created instead.

Fixed by not calling cm_process_routed_req() on RoCE systems, the
cm_process_route_req() is only for IB anyhow.

Fixes: 3971c9f6 ("IB/cm: Add interim support for routed paths")
Link: https://lore.kernel.org/r/1616420132-31005-1-git-send-email-haakon.bugge@oracle.comSigned-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/cm.c

@@ -2138,7 +2138,8 @@ static int cm_req_handler(struct cm_work *work)
 		goto destroy;
 	}
 
-	cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
+	if (cm_id_priv->av.ah_attr.type != RDMA_AH_ATTR_TYPE_ROCE)
+		cm_process_routed_req(req_msg, work->mad_recv_wc->wc);
 
 	memset(&work->path[0], 0, sizeof(work->path[0]));
 	if (cm_req_has_alt_path(req_msg))