// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
// Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES. All rights reserved.

#include <linux/if_vlan.h>
#include "act.h"
#include "pedit.h"
#include "en/tc_priv.h"
#include "en/mod_hdr.h"

static int pedit_header_offsets[] = {
        [FLOW_ACT_MANGLE_HDR_TYPE_ETH] = offsetof(struct pedit_headers, eth),
        [FLOW_ACT_MANGLE_HDR_TYPE_IP4] = offsetof(struct pedit_headers, ip4),
        [FLOW_ACT_MANGLE_HDR_TYPE_IP6] = offsetof(struct pedit_headers, ip6),
        [FLOW_ACT_MANGLE_HDR_TYPE_TCP] = offsetof(struct pedit_headers, tcp),
        [FLOW_ACT_MANGLE_HDR_TYPE_UDP] = offsetof(struct pedit_headers, udp),
};

#define pedit_header(_ph, _htype) ((void *)(_ph) + pedit_header_offsets[_htype])

static int
set_pedit_val(u8 hdr_type, u32 mask, u32 val, u32 offset,
              struct pedit_headers_action *hdrs,
              struct netlink_ext_ack *extack)
{
        u32 *curr_pmask, *curr_pval;

        curr_pmask = (u32 *)(pedit_header(&hdrs->masks, hdr_type) + offset);
        curr_pval  = (u32 *)(pedit_header(&hdrs->vals, hdr_type) + offset);

        if (*curr_pmask & mask) { /* disallow acting twice on the same location */
                NL_SET_ERR_MSG_MOD(extack,
                                   "curr_pmask and new mask same. Acting twice on same location");
                goto out_err;
        }

        *curr_pmask |= mask;
        *curr_pval  |= (val & mask);

        return 0;

out_err:
        return -EOPNOTSUPP;
}

int
mlx5e_tc_act_pedit_parse_action(struct mlx5e_priv *priv,
                                const struct flow_action_entry *act, int namespace,
                                struct pedit_headers_action *hdrs,
                                struct netlink_ext_ack *extack)
{
        u8 cmd = (act->id == FLOW_ACTION_MANGLE) ? TCA_PEDIT_KEY_EX_CMD_SET :
                                                   TCA_PEDIT_KEY_EX_CMD_ADD;
        u8 htype = act->mangle.htype;
        int err = -EOPNOTSUPP;
        u32 mask, val, offset;

        if (htype == FLOW_ACT_MANGLE_UNSPEC) {
                NL_SET_ERR_MSG_MOD(extack, "legacy pedit isn't offloaded");
                goto out_err;
        }

        if (!mlx5e_mod_hdr_max_actions(priv->mdev, namespace)) {
                NL_SET_ERR_MSG_MOD(extack, "The pedit offload action is not supported");
                goto out_err;
        }

        mask = act->mangle.mask;
        val = act->mangle.val;
        offset = act->mangle.offset;

        err = set_pedit_val(htype, ~mask, val, offset, &hdrs[cmd], extack);
        if (err)
                goto out_err;

        hdrs[cmd].pedits++;

        return 0;
out_err:
        return err;
}

static int
tc_act_parse_pedit(struct mlx5e_tc_act_parse_state *parse_state,
                   const struct flow_action_entry *act,
                   struct mlx5e_priv *priv,
                   struct mlx5_flow_attr *attr)
{
        struct mlx5_esw_flow_attr *esw_attr = attr->esw_attr;
        struct mlx5e_tc_flow *flow = parse_state->flow;
        enum mlx5_flow_namespace_type ns_type;
        int err;

        ns_type = mlx5e_get_flow_namespace(flow);

        err = mlx5e_tc_act_pedit_parse_action(flow->priv, act, ns_type, attr->parse_attr->hdrs,
                                              parse_state->extack);
        if (err)
                return err;

        attr->action |= MLX5_FLOW_CONTEXT_ACTION_MOD_HDR;

        if (ns_type == MLX5_FLOW_NAMESPACE_FDB) {
                esw_attr->split_count = esw_attr->out_count;
                parse_state->if_count = 0;
        }

        return 0;
}

struct mlx5e_tc_act mlx5e_tc_act_pedit = {
        .parse_action = tc_act_parse_pedit,
};