From 7bde7c544205bd389c0a327d86572586f13244e0 Mon Sep 17 00:00:00 2001
From: Amit Cohen <amitc@mellanox.com>
Date: Sun, 29 Dec 2019 13:40:22 +0200
Subject: [PATCH] mlxsw: spectrum_router: Skip loopback RIFs during MAC
 validation

commit 314bd842d98e1035cc40b671a71e07f48420e58f upstream.

When a router interface (RIF) is created the MAC address of the backing
netdev is verified to have the same MSBs as existing RIFs. This is
required in order to avoid changing existing RIF MAC addresses that all
share the same MSBs.

Loopback RIFs are special in this regard as they do not have a MAC
address, given they are only used to loop packets from the overlay to
the underlay.

Without this change, an error is returned when trying to create a RIF
after the creation of a GRE tunnel that is represented by a loopback
RIF. 'rif->dev->dev_addr' points to the GRE device's local IP, which
does not share the same MSBs as physical interfaces. Adding an IP
address to any physical interface results in:

Error: mlxsw_spectrum: All router interface MAC addresses must have the
same prefix.

Fix this by skipping loopback RIFs during MAC validation.

Fixes: 74bc99397438 ("mlxsw: spectrum_router: Veto unsupported RIF MAC addresses")
Signed-off-by: Amit Cohen <amitc@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 7f2d2857b5db..58c232647b36 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -6865,6 +6865,9 @@ static int mlxsw_sp_router_port_check_rif_addr(struct mlxsw_sp *mlxsw_sp,
 
 	for (i = 0; i < MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_RIFS); i++) {
 		rif = mlxsw_sp->router->rifs[i];
+		if (rif && rif->ops &&
+		    rif->ops->type == MLXSW_SP_RIF_TYPE_IPIP_LB)
+			continue;
 		if (rif && rif->dev && rif->dev != dev &&
 		    !ether_addr_equal_masked(rif->dev->dev_addr, dev_addr,
 					     mlxsw_sp->mac_mask)) {
-- 
2.7.4