RDMA/core: Fix ENODEV error for iWARP test over vlan

If traffic is over vlan, cma_validate_port() fails to match
net_device ifindex with bound_if_index and results in ENODEV error.
As iWARP gid table is static, it contains entry corresponding  to
only one net device which is either real netdev or vlan netdev for
cases like  siw attached to a vlan interface.
This patch fixes the issue by assigning bound_if_index with net
device index, if real net device obtained from bound if index matches
with net device retrieved from gid table

Fixes: f8ef1be ("RDMA/cma: Avoid GID lookups on iWARP devices")
Link: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Anumula Murali Mohan Reddy <[email protected]>
Signed-off-by: Potnuri Bharat Teja <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Leon Romanovsky <[email protected]>

Author: Anumula-Murali-Mohan-Reddy

drivers/infiniband/core/cma.c

@@ -690,6 +690,7 @@ cma_validate_port(struct ib_device *device, u32 port,
 	int bound_if_index = dev_addr->bound_dev_if;
 	int dev_type = dev_addr->dev_type;
 	struct net_device *ndev = NULL;
+	struct net_device *pdev = NULL;
 
 	if (!rdma_dev_access_netns(device, id_priv->id.route.addr.dev_addr.net))
 		goto out;
@@ -714,6 +715,21 @@ cma_validate_port(struct ib_device *device, u32 port,
 
 		rcu_read_lock();
 		ndev = rcu_dereference(sgid_attr->ndev);
+		if (ndev->ifindex != bound_if_index) {
+			pdev = dev_get_by_index_rcu(dev_addr->net, bound_if_index);
+			if (pdev) {
+				if (is_vlan_dev(pdev)) {
+					pdev = vlan_dev_real_dev(pdev);
+					if (ndev->ifindex == pdev->ifindex)
+						bound_if_index = pdev->ifindex;
+				}
+				if (is_vlan_dev(ndev)) {
+					pdev = vlan_dev_real_dev(ndev);
+					if (bound_if_index == pdev->ifindex)
+						bound_if_index = ndev->ifindex;
+				}
+			}
+		}
 		if (!net_eq(dev_net(ndev), dev_addr->net) ||
 		    ndev->ifindex != bound_if_index) {
 			rdma_put_gid_attr(sgid_attr);