IB/core: Don't resolve passive side RoCE L2 address in CMA REQ handler

The code that resolves the passive side source MAC within the rdma_cm
connection request handler was both redundant and buggy, so remove it.

It was redundant since later, when an RC QP is modified to RTR state,
the resolution will take place in the ib_core module.  It was buggy
because this callback also deals with UD SIDR exchange, for which we
incorrectly looked at the REQ member of the CM event and dereferenced
a random value.

Fixes: dd5f03beb4f7 ("IB/core: Ethernet L2 attributes in verbs/cm structures")
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
				struct ib_cm_event *ib_event)
{
	struct rdma_id_private *id_priv = cm_id->context;
	struct rdma_cm_event event;
	struct ib_cm_sidr_rep_event_param *rep = &ib_event->param.sidr_rep_rcvd;
	int ret = 0;

	if (cma_disable_callback(id_priv, RDMA_CM_CONNECT))
		return 0;

	memset(&event, 0, sizeof event);
	switch (ib_event->event) {
	case IB_CM_SIDR_REQ_ERROR:
		event.event = RDMA_CM_EVENT_UNREACHABLE;
		event.status = -ETIMEDOUT;
		break;
	case IB_CM_SIDR_REP_RECEIVED:
		event.param.ud.private_data = ib_event->private_data;
		event.param.ud.private_data_len = IB_CM_SIDR_REP_PRIVATE_DATA_SIZE;
		if (rep->status != IB_SIDR_SUCCESS) {
			event.event = RDMA_CM_EVENT_UNREACHABLE;
			event.status = ib_event->param.sidr_rep_rcvd.status;
			break;
		}
		ret = cma_set_qkey(id_priv, rep->qkey);
		if (ret) {
			event.event = RDMA_CM_EVENT_ADDR_ERROR;
			event.status = ret;
			break;
		}
		ib_init_ah_from_path(id_priv->id.device, id_priv->id.port_num,
				     id_priv->id.route.path_rec,
				     &event.param.ud.ah_attr);
		event.param.ud.qp_num = rep->qpn;
		event.param.ud.qkey = rep->qkey;
		event.event = RDMA_CM_EVENT_ESTABLISHED;
		event.status = 0;
		break;
	default:
		printk(KERN_ERR "RDMA CMA: unexpected IB CM event: %d\n",
		       ib_event->event);
		goto out;
	}

	ret = id_priv->id.event_handler(&id_priv->id, &event);
	if (ret) {
		/* Destroy the CM ID by returning a non-zero value. */
		id_priv->cm_id.ib = NULL;
		cma_exch(id_priv, RDMA_CM_DESTROYING);
		mutex_unlock(&id_priv->handler_mutex);
		rdma_destroy_id(&id_priv->id);
		return ret;
	}
out:
	mutex_unlock(&id_priv->handler_mutex);
	return ret;
}

static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
				struct ib_cm_event *ib_event)
{
	struct rdma_id_private *id_priv = cm_id->context;
	struct rdma_cm_event event;
	struct ib_cm_sidr_rep_event_param *rep = &ib_event->param.sidr_rep_rcvd;
	int ret = 0;

	if (cma_disable_callback(id_priv, RDMA_CM_CONNECT))
		return 0;

	memset(&event, 0, sizeof event);
	switch (ib_event->event) {
	case IB_CM_SIDR_REQ_ERROR:
		event.event = RDMA_CM_EVENT_UNREACHABLE;
		event.status = -ETIMEDOUT;
		break;
	case IB_CM_SIDR_REP_RECEIVED:
		event.param.ud.private_data = ib_event->private_data;
		event.param.ud.private_data_len = IB_CM_SIDR_REP_PRIVATE_DATA_SIZE;
		if (rep->status != IB_SIDR_SUCCESS) {
			event.event = RDMA_CM_EVENT_UNREACHABLE;
			event.status = ib_event->param.sidr_rep_rcvd.status;
			break;
		}
		ret = cma_set_qkey(id_priv, rep->qkey);
		if (ret) {
			event.event = RDMA_CM_EVENT_ADDR_ERROR;
			event.status = ret;
			break;
		}
		ib_init_ah_from_path(id_priv->id.device, id_priv->id.port_num,
				     id_priv->id.route.path_rec,
				     &event.param.ud.ah_attr);
		event.param.ud.qp_num = rep->qpn;
		event.param.ud.qkey = rep->qkey;
		event.event = RDMA_CM_EVENT_ESTABLISHED;
		event.status = 0;
		break;
	default:
		printk(KERN_ERR "RDMA CMA: unexpected IB CM event: %d\n",
		       ib_event->event);
		goto out;
	}

	ret = id_priv->id.event_handler(&id_priv->id, &event);
	if (ret) {
		/* Destroy the CM ID by returning a non-zero value. */
		id_priv->cm_id.ib = NULL;
		cma_exch(id_priv, RDMA_CM_DESTROYING);
		mutex_unlock(&id_priv->handler_mutex);
		rdma_destroy_id(&id_priv->id);
		return ret;
	}
out:
	mutex_unlock(&id_priv->handler_mutex);
	return ret;
}
