From 0433670e136ad879d2d52b3e05ee342a9bb052d8 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Fri, 11 Aug 2023 17:13:56 +0200 Subject: [PATCH] mlxsw: spectrum_flower: Disable learning and security lookup when redirecting It is possible to add a filter that redirects traffic from the ingress of a bridge port that is locked (i.e., performs security / SMAC lookup) and has learning enabled. For example: # ip link add name br0 type bridge # ip link set dev swp1 master br0 # bridge link set dev swp1 learning on locked on mab on # tc qdisc add dev swp1 clsact # tc filter add dev swp1 ingress pref 1 proto ip flower skip_sw src_ip 192.0.2.1 action mirred egress redirect dev swp2 In the kernel's Rx path, this filter is evaluated before the Rx handler of the bridge, which means that redirected traffic should not be affected by bridge port configuration such as learning. However, the hardware data path is a bit different and the redirect action (FORWARDING_ACTION in hardware) merely attaches a pointer to the packet, which is later used by the L2 lookup stage to understand how to forward the packet. Between both stages - ingress ACL and L2 lookup - learning and security lookup are performed, which means that redirected traffic is affected by bridge port configuration, unlike in the kernel's data path. The learning discrepancy was handled in commit 577fa14d2100 ("mlxsw: spectrum: Do not process learned records with a dummy FID") by simply ignoring learning notifications generated by the redirected traffic. A similar solution is not possible for the security / SMAC lookup since - unlike learning - the CPU is not involved and packets that failed the lookup are dropped by the device. Instead, solve this by prepending the ignore action to the redirect action and use it to instruct the device to disable both learning and the security / SMAC lookup for redirected traffic. Signed-off-by: Ido Schimmel Reviewed-by: Petr Machata Signed-off-by: Petr Machata Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum.h | 3 +++ drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c | 9 +++++++++ drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c | 10 ++++++++++ 3 files changed, 22 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h index 8da7bb0..2fed55b 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h @@ -1050,6 +1050,9 @@ int mlxsw_sp_acl_rulei_act_count(struct mlxsw_sp *mlxsw_sp, int mlxsw_sp_acl_rulei_act_fid_set(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_acl_rule_info *rulei, u16 fid, struct netlink_ext_ack *extack); +int mlxsw_sp_acl_rulei_act_ignore(struct mlxsw_sp *mlxsw_sp, + struct mlxsw_sp_acl_rule_info *rulei, + bool disable_learning, bool disable_security); int mlxsw_sp_acl_rulei_act_sample(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_acl_rule_info *rulei, struct mlxsw_sp_flow_block *block, diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c index 186161a..7c59c8a 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl.c @@ -775,6 +775,15 @@ int mlxsw_sp_acl_rulei_act_fid_set(struct mlxsw_sp *mlxsw_sp, return mlxsw_afa_block_append_fid_set(rulei->act_block, fid, extack); } +int mlxsw_sp_acl_rulei_act_ignore(struct mlxsw_sp *mlxsw_sp, + struct mlxsw_sp_acl_rule_info *rulei, + bool disable_learning, bool disable_security) +{ + return mlxsw_afa_block_append_ignore(rulei->act_block, + disable_learning, + disable_security); +} + int mlxsw_sp_acl_rulei_act_sample(struct mlxsw_sp *mlxsw_sp, struct mlxsw_sp_acl_rule_info *rulei, struct mlxsw_sp_flow_block *block, diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c index af3f57d..9fd1ca0 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c @@ -160,6 +160,16 @@ static int mlxsw_sp_flower_parse_actions(struct mlxsw_sp *mlxsw_sp, */ rulei->egress_bind_blocker = 1; + /* Ignore learning and security lookup as redirection + * using ingress filters happens before the bridge. + */ + err = mlxsw_sp_acl_rulei_act_ignore(mlxsw_sp, rulei, + true, true); + if (err) { + NL_SET_ERR_MSG_MOD(extack, "Cannot append ignore action"); + return err; + } + fid = mlxsw_sp_acl_dummy_fid(mlxsw_sp); fid_index = mlxsw_sp_fid_index(fid); err = mlxsw_sp_acl_rulei_act_fid_set(mlxsw_sp, rulei, -- 2.7.4