// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */

#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/random.h>
#include <net/vxlan.h>

#include "reg.h"
#include "spectrum_nve.h"

/* Eth (18B) | IPv6 (40B) | UDP (8B) | VxLAN (8B) | Eth (14B) | IPv6 (40B)
 *
 * In the worst case - where we have a VLAN tag on the outer Ethernet
 * header and IPv6 in overlay and underlay - we need to parse 128 bytes
 */
#define MLXSW_SP_NVE_VXLAN_PARSING_DEPTH 128
#define MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH 96

#define MLXSW_SP_NVE_VXLAN_SUPPORTED_FLAGS	VXLAN_F_UDP_ZERO_CSUM_TX

static bool mlxsw_sp1_nve_vxlan_can_offload(const struct mlxsw_sp_nve *nve,
					    const struct net_device *dev,
					    struct netlink_ext_ack *extack)
{
	struct vxlan_dev *vxlan = netdev_priv(dev);
	struct vxlan_config *cfg = &vxlan->cfg;

	if (cfg->saddr.sa.sa_family != AF_INET) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Only IPv4 underlay is supported");
		return false;
	}

	if (vxlan_addr_multicast(&cfg->remote_ip)) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Multicast destination IP is not supported");
		return false;
	}

	if (vxlan_addr_any(&cfg->saddr)) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Source address must be specified");
		return false;
	}

	if (cfg->remote_ifindex) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Local interface is not supported");
		return false;
	}

	if (cfg->port_min || cfg->port_max) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Only default UDP source port range is supported");
		return false;
	}

	if (cfg->tos != 1) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: TOS must be configured to inherit");
		return false;
	}

	if (cfg->flags & VXLAN_F_TTL_INHERIT) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: TTL must not be configured to inherit");
		return false;
	}

	if (cfg->flags & VXLAN_F_LEARN) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Learning is not supported");
		return false;
	}

	if (!(cfg->flags & VXLAN_F_UDP_ZERO_CSUM_TX)) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: UDP checksum is not supported");
		return false;
	}

	if (cfg->flags & ~MLXSW_SP_NVE_VXLAN_SUPPORTED_FLAGS) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Unsupported flag");
		return false;
	}

	if (cfg->ttl == 0) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: TTL must not be configured to 0");
		return false;
	}

	if (cfg->label != 0) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Flow label must be configured to 0");
		return false;
	}

	return true;
}

static void mlxsw_sp_nve_vxlan_config(const struct mlxsw_sp_nve *nve,
				      const struct net_device *dev,
				      struct mlxsw_sp_nve_config *config)
{
	struct vxlan_dev *vxlan = netdev_priv(dev);
	struct vxlan_config *cfg = &vxlan->cfg;

	config->type = MLXSW_SP_NVE_TYPE_VXLAN;
	config->ttl = cfg->ttl;
	config->flowlabel = cfg->label;
	config->learning_en = cfg->flags & VXLAN_F_LEARN ? 1 : 0;
	config->ul_tb_id = RT_TABLE_MAIN;
	config->ul_proto = MLXSW_SP_L3_PROTO_IPV4;
	config->ul_sip.addr4 = cfg->saddr.sin.sin_addr.s_addr;
	config->udp_dport = cfg->dst_port;
}

static int mlxsw_sp_nve_parsing_set(struct mlxsw_sp *mlxsw_sp,
				    unsigned int parsing_depth,
				    __be16 udp_dport)
{
	char mprs_pl[MLXSW_REG_MPRS_LEN];

	mlxsw_reg_mprs_pack(mprs_pl, parsing_depth, be16_to_cpu(udp_dport));
	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mprs), mprs_pl);
}

static int
mlxsw_sp1_nve_vxlan_config_set(struct mlxsw_sp *mlxsw_sp,
			       const struct mlxsw_sp_nve_config *config)
{
	char tngcr_pl[MLXSW_REG_TNGCR_LEN];
	u16 ul_vr_id;
	u8 udp_sport;
	int err;

	err = mlxsw_sp_router_tb_id_vr_id(mlxsw_sp, config->ul_tb_id,
					  &ul_vr_id);
	if (err)
		return err;

	mlxsw_reg_tngcr_pack(tngcr_pl, MLXSW_REG_TNGCR_TYPE_VXLAN, true,
			     config->ttl);
	/* VxLAN driver's default UDP source port range is 32768 (0x8000)
	 * to 60999 (0xee47). Set the upper 8 bits of the UDP source port
	 * to a random number between 0x80 and 0xee
	 */
	get_random_bytes(&udp_sport, sizeof(udp_sport));
	udp_sport = (udp_sport % (0xee - 0x80 + 1)) + 0x80;
	mlxsw_reg_tngcr_nve_udp_sport_prefix_set(tngcr_pl, udp_sport);
	mlxsw_reg_tngcr_learn_enable_set(tngcr_pl, config->learning_en);
	mlxsw_reg_tngcr_underlay_virtual_router_set(tngcr_pl, ul_vr_id);
	mlxsw_reg_tngcr_usipv4_set(tngcr_pl, be32_to_cpu(config->ul_sip.addr4));

	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(tngcr), tngcr_pl);
}

static void mlxsw_sp1_nve_vxlan_config_clear(struct mlxsw_sp *mlxsw_sp)
{
	char tngcr_pl[MLXSW_REG_TNGCR_LEN];

	mlxsw_reg_tngcr_pack(tngcr_pl, MLXSW_REG_TNGCR_TYPE_VXLAN, false, 0);

	mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(tngcr), tngcr_pl);
}

static int mlxsw_sp1_nve_vxlan_rtdp_set(struct mlxsw_sp *mlxsw_sp,
					unsigned int tunnel_index)
{
	char rtdp_pl[MLXSW_REG_RTDP_LEN];

	mlxsw_reg_rtdp_pack(rtdp_pl, MLXSW_REG_RTDP_TYPE_NVE, tunnel_index);

	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(rtdp), rtdp_pl);
}

static int mlxsw_sp1_nve_vxlan_init(struct mlxsw_sp_nve *nve,
				    const struct mlxsw_sp_nve_config *config)
{
	struct mlxsw_sp *mlxsw_sp = nve->mlxsw_sp;
	int err;

	err = mlxsw_sp_nve_parsing_set(mlxsw_sp,
				       MLXSW_SP_NVE_VXLAN_PARSING_DEPTH,
				       config->udp_dport);
	if (err)
		return err;

	err = mlxsw_sp1_nve_vxlan_config_set(mlxsw_sp, config);
	if (err)
		goto err_config_set;

	err = mlxsw_sp1_nve_vxlan_rtdp_set(mlxsw_sp, nve->tunnel_index);
	if (err)
		goto err_rtdp_set;

	err = mlxsw_sp_router_nve_promote_decap(mlxsw_sp, config->ul_tb_id,
						config->ul_proto,
						&config->ul_sip,
						nve->tunnel_index);
	if (err)
		goto err_promote_decap;

	return 0;

err_promote_decap:
err_rtdp_set:
	mlxsw_sp1_nve_vxlan_config_clear(mlxsw_sp);
err_config_set:
	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
				 config->udp_dport);
	return err;
}

static void mlxsw_sp1_nve_vxlan_fini(struct mlxsw_sp_nve *nve)
{
	struct mlxsw_sp_nve_config *config = &nve->config;
	struct mlxsw_sp *mlxsw_sp = nve->mlxsw_sp;

	mlxsw_sp_router_nve_demote_decap(mlxsw_sp, config->ul_tb_id,
					 config->ul_proto, &config->ul_sip);
	mlxsw_sp1_nve_vxlan_config_clear(mlxsw_sp);
	mlxsw_sp_nve_parsing_set(mlxsw_sp, MLXSW_SP_NVE_DEFAULT_PARSING_DEPTH,
				 config->udp_dport);
}

const struct mlxsw_sp_nve_ops mlxsw_sp1_nve_vxlan_ops = {
	.type		= MLXSW_SP_NVE_TYPE_VXLAN,
	.can_offload	= mlxsw_sp1_nve_vxlan_can_offload,
	.nve_config	= mlxsw_sp_nve_vxlan_config,
	.init		= mlxsw_sp1_nve_vxlan_init,
	.fini		= mlxsw_sp1_nve_vxlan_fini,
};

static bool mlxsw_sp2_nve_vxlan_can_offload(const struct mlxsw_sp_nve *nve,
					    const struct net_device *dev,
					    struct netlink_ext_ack *extack)
{
	return false;
}

static int mlxsw_sp2_nve_vxlan_init(struct mlxsw_sp_nve *nve,
				    const struct mlxsw_sp_nve_config *config)
{
	return -EOPNOTSUPP;
}

static void mlxsw_sp2_nve_vxlan_fini(struct mlxsw_sp_nve *nve)
{
}

const struct mlxsw_sp_nve_ops mlxsw_sp2_nve_vxlan_ops = {
	.type		= MLXSW_SP_NVE_TYPE_VXLAN,
	.can_offload	= mlxsw_sp2_nve_vxlan_can_offload,
	.nve_config	= mlxsw_sp_nve_vxlan_config,
	.init		= mlxsw_sp2_nve_vxlan_init,
	.fini		= mlxsw_sp2_nve_vxlan_fini,
};