/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/bitfield.h>
#include <net/pkt_cls.h>

#include "cmsg.h"
#include "main.h"

static void
nfp_flower_compile_meta_tci(struct nfp_flower_meta_two *frame,
			    struct tc_cls_flower_offload *flow, u8 key_type,
			    bool mask_version)
{
	struct flow_dissector_key_vlan *flow_vlan;
	u16 tmp_tci;

	/* Populate the metadata frame. */
	frame->nfp_flow_key_layer = key_type;
	frame->mask_id = ~0;

	if (mask_version) {
		frame->tci = cpu_to_be16(~0);
		return;
	}

	flow_vlan = skb_flow_dissector_target(flow->dissector,
					      FLOW_DISSECTOR_KEY_VLAN,
					      flow->key);

	/* Populate the tci field. */
	if (!flow_vlan->vlan_id) {
		tmp_tci = 0;
	} else {
		tmp_tci = FIELD_PREP(NFP_FLOWER_MASK_VLAN_PRIO,
				     flow_vlan->vlan_priority) |
			  FIELD_PREP(NFP_FLOWER_MASK_VLAN_VID,
				     flow_vlan->vlan_id) |
			  NFP_FLOWER_MASK_VLAN_CFI;
	}
	frame->tci = cpu_to_be16(tmp_tci);
}

static void
nfp_flower_compile_meta(struct nfp_flower_meta_one *frame, u8 key_type)
{
	frame->nfp_flow_key_layer = key_type;
	frame->mask_id = 0;
	frame->reserved = 0;
}

static int
nfp_flower_compile_port(struct nfp_flower_in_port *frame, u32 cmsg_port,
			bool mask_version)
{
	if (mask_version) {
		frame->in_port = cpu_to_be32(~0);
		return 0;
	}

	frame->in_port = cpu_to_be32(cmsg_port);

	return 0;
}

static void
nfp_flower_compile_mac(struct nfp_flower_mac_mpls *frame,
		       struct tc_cls_flower_offload *flow,
		       bool mask_version)
{
	struct fl_flow_key *target = mask_version ? flow->mask : flow->key;
	struct flow_dissector_key_eth_addrs *flow_mac;

	flow_mac = skb_flow_dissector_target(flow->dissector,
					     FLOW_DISSECTOR_KEY_ETH_ADDRS,
					     target);

	memset(frame, 0, sizeof(struct nfp_flower_mac_mpls));

	/* Populate mac frame. */
	ether_addr_copy(frame->mac_dst, &flow_mac->dst[0]);
	ether_addr_copy(frame->mac_src, &flow_mac->src[0]);

	if (mask_version)
		frame->mpls_lse = cpu_to_be32(~0);
}

static void
nfp_flower_compile_tport(struct nfp_flower_tp_ports *frame,
			 struct tc_cls_flower_offload *flow,
			 bool mask_version)
{
	struct fl_flow_key *target = mask_version ? flow->mask : flow->key;
	struct flow_dissector_key_ports *flow_tp;

	flow_tp = skb_flow_dissector_target(flow->dissector,
					    FLOW_DISSECTOR_KEY_PORTS,
					    target);

	frame->port_src = flow_tp->src;
	frame->port_dst = flow_tp->dst;
}

static void
nfp_flower_compile_ipv4(struct nfp_flower_ipv4 *frame,
			struct tc_cls_flower_offload *flow,
			bool mask_version)
{
	struct fl_flow_key *target = mask_version ? flow->mask : flow->key;
	struct flow_dissector_key_ipv4_addrs *flow_ipv4;
	struct flow_dissector_key_basic *flow_basic;

	flow_ipv4 = skb_flow_dissector_target(flow->dissector,
					      FLOW_DISSECTOR_KEY_IPV4_ADDRS,
					      target);

	flow_basic = skb_flow_dissector_target(flow->dissector,
					       FLOW_DISSECTOR_KEY_BASIC,
					       target);

	/* Populate IPv4 frame. */
	frame->reserved = 0;
	frame->ipv4_src = flow_ipv4->src;
	frame->ipv4_dst = flow_ipv4->dst;
	frame->proto = flow_basic->ip_proto;
	/* Wildcard TOS/TTL for now. */
	frame->tos = 0;
	frame->ttl = 0;
}

static void
nfp_flower_compile_ipv6(struct nfp_flower_ipv6 *frame,
			struct tc_cls_flower_offload *flow,
			bool mask_version)
{
	struct fl_flow_key *target = mask_version ? flow->mask : flow->key;
	struct flow_dissector_key_ipv6_addrs *flow_ipv6;
	struct flow_dissector_key_basic *flow_basic;

	flow_ipv6 = skb_flow_dissector_target(flow->dissector,
					      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
					      target);

	flow_basic = skb_flow_dissector_target(flow->dissector,
					       FLOW_DISSECTOR_KEY_BASIC,
					       target);

	/* Populate IPv6 frame. */
	frame->reserved = 0;
	frame->ipv6_src = flow_ipv6->src;
	frame->ipv6_dst = flow_ipv6->dst;
	frame->proto = flow_basic->ip_proto;
	/* Wildcard LABEL/TOS/TTL for now. */
	frame->ipv6_flow_label_exthdr = 0;
	frame->tos = 0;
	frame->ttl = 0;
}

int nfp_flower_compile_flow_match(struct tc_cls_flower_offload *flow,
				  struct nfp_fl_key_ls *key_ls,
				  struct net_device *netdev,
				  struct nfp_fl_payload *nfp_flow)
{
	int err;
	u8 *ext;
	u8 *msk;

	memset(nfp_flow->unmasked_data, 0, key_ls->key_size);
	memset(nfp_flow->mask_data, 0, key_ls->key_size);

	ext = nfp_flow->unmasked_data;
	msk = nfp_flow->mask_data;
	if (NFP_FLOWER_LAYER_PORT & key_ls->key_layer) {
		/* Populate Exact Metadata. */
		nfp_flower_compile_meta_tci((struct nfp_flower_meta_two *)ext,
					    flow, key_ls->key_layer, false);
		/* Populate Mask Metadata. */
		nfp_flower_compile_meta_tci((struct nfp_flower_meta_two *)msk,
					    flow, key_ls->key_layer, true);
		ext += sizeof(struct nfp_flower_meta_two);
		msk += sizeof(struct nfp_flower_meta_two);

		/* Populate Exact Port data. */
		err = nfp_flower_compile_port((struct nfp_flower_in_port *)ext,
					      nfp_repr_get_port_id(netdev),
					      false);
		if (err)
			return err;

		/* Populate Mask Port Data. */
		err = nfp_flower_compile_port((struct nfp_flower_in_port *)msk,
					      nfp_repr_get_port_id(netdev),
					      true);
		if (err)
			return err;

		ext += sizeof(struct nfp_flower_in_port);
		msk += sizeof(struct nfp_flower_in_port);
	} else {
		/* Populate Exact Metadata. */
		nfp_flower_compile_meta((struct nfp_flower_meta_one *)ext,
					key_ls->key_layer);
		/* Populate Mask Metadata. */
		nfp_flower_compile_meta((struct nfp_flower_meta_one *)msk,
					key_ls->key_layer);
		ext += sizeof(struct nfp_flower_meta_one);
		msk += sizeof(struct nfp_flower_meta_one);
	}

	if (NFP_FLOWER_LAYER_META & key_ls->key_layer) {
		/* Additional Metadata Fields.
		 * Currently unsupported.
		 */
		return -EOPNOTSUPP;
	}

	if (NFP_FLOWER_LAYER_MAC & key_ls->key_layer) {
		/* Populate Exact MAC Data. */
		nfp_flower_compile_mac((struct nfp_flower_mac_mpls *)ext,
				       flow, false);
		/* Populate Mask MAC Data. */
		nfp_flower_compile_mac((struct nfp_flower_mac_mpls *)msk,
				       flow, true);
		ext += sizeof(struct nfp_flower_mac_mpls);
		msk += sizeof(struct nfp_flower_mac_mpls);
	}

	if (NFP_FLOWER_LAYER_TP & key_ls->key_layer) {
		/* Populate Exact TP Data. */
		nfp_flower_compile_tport((struct nfp_flower_tp_ports *)ext,
					 flow, false);
		/* Populate Mask TP Data. */
		nfp_flower_compile_tport((struct nfp_flower_tp_ports *)msk,
					 flow, true);
		ext += sizeof(struct nfp_flower_tp_ports);
		msk += sizeof(struct nfp_flower_tp_ports);
	}

	if (NFP_FLOWER_LAYER_IPV4 & key_ls->key_layer) {
		/* Populate Exact IPv4 Data. */
		nfp_flower_compile_ipv4((struct nfp_flower_ipv4 *)ext,
					flow, false);
		/* Populate Mask IPv4 Data. */
		nfp_flower_compile_ipv4((struct nfp_flower_ipv4 *)msk,
					flow, true);
		ext += sizeof(struct nfp_flower_ipv4);
		msk += sizeof(struct nfp_flower_ipv4);
	}

	if (NFP_FLOWER_LAYER_IPV6 & key_ls->key_layer) {
		/* Populate Exact IPv4 Data. */
		nfp_flower_compile_ipv6((struct nfp_flower_ipv6 *)ext,
					flow, false);
		/* Populate Mask IPv4 Data. */
		nfp_flower_compile_ipv6((struct nfp_flower_ipv6 *)msk,
					flow, true);
		ext += sizeof(struct nfp_flower_ipv6);
		msk += sizeof(struct nfp_flower_ipv6);
	}

	return 0;
}