// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2017-2020 Mellanox Technologies. All rights reserved */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <net/net_namespace.h>

#include "spectrum.h"

struct mlxsw_sp_flow_block *
mlxsw_sp_flow_block_create(struct mlxsw_sp *mlxsw_sp, struct net *net)
{
	struct mlxsw_sp_flow_block *block;

	block = kzalloc(sizeof(*block), GFP_KERNEL);
	if (!block)
		return NULL;
	INIT_LIST_HEAD(&block->binding_list);
	INIT_LIST_HEAD(&block->mall.list);
	block->mlxsw_sp = mlxsw_sp;
	block->net = net;
	return block;
}

void mlxsw_sp_flow_block_destroy(struct mlxsw_sp_flow_block *block)
{
	WARN_ON(!list_empty(&block->binding_list));
	kfree(block);
}

static struct mlxsw_sp_flow_block_binding *
mlxsw_sp_flow_block_lookup(struct mlxsw_sp_flow_block *block,
			   struct mlxsw_sp_port *mlxsw_sp_port, bool ingress)
{
	struct mlxsw_sp_flow_block_binding *binding;

	list_for_each_entry(binding, &block->binding_list, list)
		if (binding->mlxsw_sp_port == mlxsw_sp_port &&
		    binding->ingress == ingress)
			return binding;
	return NULL;
}

static bool
mlxsw_sp_flow_block_ruleset_bound(const struct mlxsw_sp_flow_block *block)
{
	return block->ruleset_zero;
}

static int mlxsw_sp_flow_block_bind(struct mlxsw_sp *mlxsw_sp,
				    struct mlxsw_sp_flow_block *block,
				    struct mlxsw_sp_port *mlxsw_sp_port,
				    bool ingress,
				    struct netlink_ext_ack *extack)
{
	struct mlxsw_sp_flow_block_binding *binding;
	int err;

	if (WARN_ON(mlxsw_sp_flow_block_lookup(block, mlxsw_sp_port, ingress)))
		return -EEXIST;

	if (ingress && block->ingress_blocker_rule_count) {
		NL_SET_ERR_MSG_MOD(extack, "Block cannot be bound to ingress because it contains unsupported rules");
		return -EOPNOTSUPP;
	}

	if (!ingress && block->egress_blocker_rule_count) {
		NL_SET_ERR_MSG_MOD(extack, "Block cannot be bound to egress because it contains unsupported rules");
		return -EOPNOTSUPP;
	}

	err = mlxsw_sp_mall_port_bind(block, mlxsw_sp_port);
	if (err)
		return err;

	binding = kzalloc(sizeof(*binding), GFP_KERNEL);
	if (!binding) {
		err = -ENOMEM;
		goto err_binding_alloc;
	}
	binding->mlxsw_sp_port = mlxsw_sp_port;
	binding->ingress = ingress;

	if (mlxsw_sp_flow_block_ruleset_bound(block)) {
		err = mlxsw_sp_acl_ruleset_bind(mlxsw_sp, block, binding);
		if (err)
			goto err_ruleset_bind;
	}

	if (ingress)
		block->ingress_binding_count++;
	else
		block->egress_binding_count++;
	list_add(&binding->list, &block->binding_list);
	return 0;

err_ruleset_bind:
	kfree(binding);
err_binding_alloc:
	mlxsw_sp_mall_port_unbind(block, mlxsw_sp_port);

	return err;
}

static int mlxsw_sp_flow_block_unbind(struct mlxsw_sp *mlxsw_sp,
				      struct mlxsw_sp_flow_block *block,
				      struct mlxsw_sp_port *mlxsw_sp_port,
				      bool ingress)
{
	struct mlxsw_sp_flow_block_binding *binding;

	binding = mlxsw_sp_flow_block_lookup(block, mlxsw_sp_port, ingress);
	if (!binding)
		return -ENOENT;

	list_del(&binding->list);

	if (ingress)
		block->ingress_binding_count--;
	else
		block->egress_binding_count--;

	if (mlxsw_sp_flow_block_ruleset_bound(block))
		mlxsw_sp_acl_ruleset_unbind(mlxsw_sp, block, binding);

	kfree(binding);

	mlxsw_sp_mall_port_unbind(block, mlxsw_sp_port);

	return 0;
}

static int mlxsw_sp_flow_block_mall_cb(struct mlxsw_sp_flow_block *flow_block,
				       struct tc_cls_matchall_offload *f)
{
	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_flow_block_mlxsw_sp(flow_block);

	switch (f->command) {
	case TC_CLSMATCHALL_REPLACE:
		return mlxsw_sp_mall_replace(mlxsw_sp, flow_block, f);
	case TC_CLSMATCHALL_DESTROY:
		mlxsw_sp_mall_destroy(flow_block, f);
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int mlxsw_sp_flow_block_flower_cb(struct mlxsw_sp_flow_block *flow_block,
					 struct flow_cls_offload *f)
{
	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_flow_block_mlxsw_sp(flow_block);

	switch (f->command) {
	case FLOW_CLS_REPLACE:
		return mlxsw_sp_flower_replace(mlxsw_sp, flow_block, f);
	case FLOW_CLS_DESTROY:
		mlxsw_sp_flower_destroy(mlxsw_sp, flow_block, f);
		return 0;
	case FLOW_CLS_STATS:
		return mlxsw_sp_flower_stats(mlxsw_sp, flow_block, f);
	case FLOW_CLS_TMPLT_CREATE:
		return mlxsw_sp_flower_tmplt_create(mlxsw_sp, flow_block, f);
	case FLOW_CLS_TMPLT_DESTROY:
		mlxsw_sp_flower_tmplt_destroy(mlxsw_sp, flow_block, f);
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static int mlxsw_sp_flow_block_cb(enum tc_setup_type type,
				  void *type_data, void *cb_priv)
{
	struct mlxsw_sp_flow_block *flow_block = cb_priv;

	if (mlxsw_sp_flow_block_disabled(flow_block))
		return -EOPNOTSUPP;

	switch (type) {
	case TC_SETUP_CLSMATCHALL:
		return mlxsw_sp_flow_block_mall_cb(flow_block, type_data);
	case TC_SETUP_CLSFLOWER:
		return mlxsw_sp_flow_block_flower_cb(flow_block, type_data);
	default:
		return -EOPNOTSUPP;
	}
}

static void mlxsw_sp_tc_block_release(void *cb_priv)
{
	struct mlxsw_sp_flow_block *flow_block = cb_priv;

	mlxsw_sp_flow_block_destroy(flow_block);
}

static LIST_HEAD(mlxsw_sp_block_cb_list);

static int mlxsw_sp_setup_tc_block_bind(struct mlxsw_sp_port *mlxsw_sp_port,
					struct flow_block_offload *f,
					bool ingress)
{
	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
	struct mlxsw_sp_flow_block *flow_block;
	struct flow_block_cb *block_cb;
	bool register_block = false;
	int err;

	block_cb = flow_block_cb_lookup(f->block, mlxsw_sp_flow_block_cb,
					mlxsw_sp);
	if (!block_cb) {
		flow_block = mlxsw_sp_flow_block_create(mlxsw_sp, f->net);
		if (!flow_block)
			return -ENOMEM;
		block_cb = flow_block_cb_alloc(mlxsw_sp_flow_block_cb,
					       mlxsw_sp, flow_block,
					       mlxsw_sp_tc_block_release);
		if (IS_ERR(block_cb)) {
			mlxsw_sp_flow_block_destroy(flow_block);
			return PTR_ERR(block_cb);
		}
		register_block = true;
	} else {
		flow_block = flow_block_cb_priv(block_cb);
	}
	flow_block_cb_incref(block_cb);
	err = mlxsw_sp_flow_block_bind(mlxsw_sp, flow_block,
				       mlxsw_sp_port, ingress, f->extack);
	if (err)
		goto err_block_bind;

	if (ingress)
		mlxsw_sp_port->ing_flow_block = flow_block;
	else
		mlxsw_sp_port->eg_flow_block = flow_block;

	if (register_block) {
		flow_block_cb_add(block_cb, f);
		list_add_tail(&block_cb->driver_list, &mlxsw_sp_block_cb_list);
	}

	return 0;

err_block_bind:
	if (!flow_block_cb_decref(block_cb))
		flow_block_cb_free(block_cb);
	return err;
}

static void mlxsw_sp_setup_tc_block_unbind(struct mlxsw_sp_port *mlxsw_sp_port,
					   struct flow_block_offload *f,
					   bool ingress)
{
	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
	struct mlxsw_sp_flow_block *flow_block;
	struct flow_block_cb *block_cb;
	int err;

	block_cb = flow_block_cb_lookup(f->block, mlxsw_sp_flow_block_cb,
					mlxsw_sp);
	if (!block_cb)
		return;

	if (ingress)
		mlxsw_sp_port->ing_flow_block = NULL;
	else
		mlxsw_sp_port->eg_flow_block = NULL;

	flow_block = flow_block_cb_priv(block_cb);
	err = mlxsw_sp_flow_block_unbind(mlxsw_sp, flow_block,
					 mlxsw_sp_port, ingress);
	if (!err && !flow_block_cb_decref(block_cb)) {
		flow_block_cb_remove(block_cb, f);
		list_del(&block_cb->driver_list);
	}
}

int mlxsw_sp_setup_tc_block_clsact(struct mlxsw_sp_port *mlxsw_sp_port,
				   struct flow_block_offload *f,
				   bool ingress)
{
	f->driver_block_list = &mlxsw_sp_block_cb_list;

	switch (f->command) {
	case FLOW_BLOCK_BIND:
		return mlxsw_sp_setup_tc_block_bind(mlxsw_sp_port, f, ingress);
	case FLOW_BLOCK_UNBIND:
		mlxsw_sp_setup_tc_block_unbind(mlxsw_sp_port, f, ingress);
		return 0;
	default:
		return -EOPNOTSUPP;
	}
}