root/drivers/net/ethernet/mellanox/mlx5/core/en/tc/act/mpls.c
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
// Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.

#include <net/bareudp.h>
#include "act.h"
#include "en/tc_priv.h"

static bool
tc_act_can_offload_mpls_push(struct mlx5e_tc_act_parse_state *parse_state,
                             const struct flow_action_entry *act,
                             int act_index,
                             struct mlx5_flow_attr *attr)
{
        struct netlink_ext_ack *extack = parse_state->extack;
        struct mlx5e_priv *priv = parse_state->flow->priv;

        if (!MLX5_CAP_ESW_FLOWTABLE_FDB(priv->mdev, reformat_l2_to_l3_tunnel) ||
            act->mpls_push.proto != htons(ETH_P_MPLS_UC)) {
                NL_SET_ERR_MSG_MOD(extack, "mpls push is supported only for mpls_uc protocol");
                return false;
        }

        return true;
}

static void
copy_mpls_info(struct mlx5e_mpls_info *mpls_info,
               const struct flow_action_entry *act)
{
        mpls_info->label = act->mpls_push.label;
        mpls_info->tc = act->mpls_push.tc;
        mpls_info->bos = act->mpls_push.bos;
        mpls_info->ttl = act->mpls_push.ttl;
}

static int
tc_act_parse_mpls_push(struct mlx5e_tc_act_parse_state *parse_state,
                       const struct flow_action_entry *act,
                       struct mlx5e_priv *priv,
                       struct mlx5_flow_attr *attr)
{
        parse_state->mpls_push = true;
        copy_mpls_info(&parse_state->mpls_info, act);

        return 0;
}

static bool
tc_act_can_offload_mpls_pop(struct mlx5e_tc_act_parse_state *parse_state,
                            const struct flow_action_entry *act,
                            int act_index,
                            struct mlx5_flow_attr *attr)
{
        struct netlink_ext_ack *extack = parse_state->extack;
        struct net_device *filter_dev;

        filter_dev = attr->parse_attr->filter_dev;

        /* we only support mpls pop if it is the first action
         * or it is second action after tunnel key unset
         * and the filter net device is bareudp. Subsequent
         * actions can be pedit and the last can be mirred
         * egress redirect.
         */
        if ((act_index == 1 && !parse_state->decap) || act_index > 1) {
                NL_SET_ERR_MSG_MOD(extack, "mpls pop supported only as first action or with decap");
                return false;
        }

        if (!netif_is_bareudp(filter_dev)) {
                NL_SET_ERR_MSG_MOD(extack, "mpls pop supported only on bareudp devices");
                return false;
        }

        return true;
}

static int
tc_act_parse_mpls_pop(struct mlx5e_tc_act_parse_state *parse_state,
                      const struct flow_action_entry *act,
                      struct mlx5e_priv *priv,
                      struct mlx5_flow_attr *attr)
{
        attr->esw_attr->eth.h_proto = act->mpls_pop.proto;
        attr->action |= MLX5_FLOW_CONTEXT_ACTION_PACKET_REFORMAT;
        flow_flag_set(parse_state->flow, L3_TO_L2_DECAP);

        return 0;
}

struct mlx5e_tc_act mlx5e_tc_act_mpls_push = {
        .can_offload = tc_act_can_offload_mpls_push,
        .parse_action = tc_act_parse_mpls_push,
};

struct mlx5e_tc_act mlx5e_tc_act_mpls_pop = {
        .can_offload = tc_act_can_offload_mpls_pop,
        .parse_action = tc_act_parse_mpls_pop,
};