The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Thanks, Sasha

------------------ original commit in Linus's tree ------------------

From 66167c310deb4ac1725f81004fb4b504676ad0bf Mon Sep 17 00:00:00 2001

From: Ido Schimmel idosch@nvidia.com Date: Mon, 29 Mar 2021 11:29:23 +0300 Subject: [PATCH] mlxsw: spectrum: Fix ECN marking in tunnel decapsulation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

Cited commit changed the behavior of the software data path with regards to the ECN marking of decapsulated packets. However, the commit did not change other callers of __INET_ECN_decapsulate(), namely mlxsw. The driver is using the function in order to ensure that the hardware and software data paths act the same with regards to the ECN marking of decapsulated packets.

The discrepancy was uncovered by commit 5aa3c334a449 ("selftests: forwarding: vxlan_bridge_1d: Fix vxlan ecn decapsulate value") that aligned the selftest to the new behavior. Without this patch the selftest passes when used with veth pairs, but fails when used with mlxsw netdevs.

Fix this by instructing the device to propagate the ECT(1) mark from the outer header to the inner header when the inner header is ECT(0), for both NVE and IP-in-IP tunnels.

A helper is added in order not to duplicate the code between both tunnel types.

Fixes: b723748750ec ("tunnel: Propagate ECT(1) when decapsulating as recommended by RFC6040") Signed-off-by: Ido Schimmel idosch@nvidia.com Reviewed-by: Petr Machata petrm@nvidia.com Acked-by: Toke Høiland-Jørgensen toke@redhat.com Signed-off-by: David S. Miller davem@davemloft.net --- drivers/net/ethernet/mellanox/mlxsw/spectrum.h | 15 +++++++++++++++ .../net/ethernet/mellanox/mlxsw/spectrum_ipip.c | 7 +++---- .../net/ethernet/mellanox/mlxsw/spectrum_nve.c | 7 +++---- 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h index d9d9e1f488f9..ba28ac7e79bc 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h @@ -21,6 +21,7 @@ #include <net/red.h> #include <net/vxlan.h> #include <net/flow_offload.h> +#include <net/inet_ecn.h>

#include "port.h" #include "core.h" @@ -347,6 +348,20 @@ struct mlxsw_sp_port_type_speed_ops { u32 (*ptys_proto_cap_masked_get)(u32 eth_proto_cap); };

+static inline u8 mlxsw_sp_tunnel_ecn_decap(u8 outer_ecn, u8 inner_ecn, + bool *trap_en) +{ + bool set_ce = false; + + *trap_en = !!__INET_ECN_decapsulate(outer_ecn, inner_ecn, &set_ce); + if (set_ce) + return INET_ECN_CE; + else if (outer_ecn == INET_ECN_ECT_1 && inner_ecn == INET_ECN_ECT_0) + return INET_ECN_ECT_1; + else + return inner_ecn; +} + static inline struct net_device * mlxsw_sp_bridge_vxlan_dev_find(struct net_device *br_dev) { diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c index 6ccca39bae84..64a8f838eb53 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ipip.c @@ -335,12 +335,11 @@ static int mlxsw_sp_ipip_ecn_decap_init_one(struct mlxsw_sp *mlxsw_sp, u8 inner_ecn, u8 outer_ecn) { char tidem_pl[MLXSW_REG_TIDEM_LEN]; - bool trap_en, set_ce = false; u8 new_inner_ecn; + bool trap_en;

- trap_en = __INET_ECN_decapsulate(outer_ecn, inner_ecn, &set_ce); - new_inner_ecn = set_ce ? INET_ECN_CE : inner_ecn; - + new_inner_ecn = mlxsw_sp_tunnel_ecn_decap(outer_ecn, inner_ecn, + &trap_en); mlxsw_reg_tidem_pack(tidem_pl, outer_ecn, inner_ecn, new_inner_ecn, trap_en, trap_en ? MLXSW_TRAP_ID_DECAP_ECN0 : 0); return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(tidem), tidem_pl); diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c index e5ec595593f4..9eba8fa684ae 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve.c @@ -909,12 +909,11 @@ static int __mlxsw_sp_nve_ecn_decap_init(struct mlxsw_sp *mlxsw_sp, u8 inner_ecn, u8 outer_ecn) { char tndem_pl[MLXSW_REG_TNDEM_LEN]; - bool trap_en, set_ce = false; u8 new_inner_ecn; + bool trap_en;

- trap_en = !!__INET_ECN_decapsulate(outer_ecn, inner_ecn, &set_ce); - new_inner_ecn = set_ce ? INET_ECN_CE : inner_ecn; - + new_inner_ecn = mlxsw_sp_tunnel_ecn_decap(outer_ecn, inner_ecn, + &trap_en); mlxsw_reg_tndem_pack(tndem_pl, outer_ecn, inner_ecn, new_inner_ecn, trap_en, trap_en ? MLXSW_TRAP_ID_DECAP_ECN0 : 0); return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(tndem), tndem_pl);