// Copyright (c) 2022 Tigera, Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package bpfutils

import (
	"os"
	"sync"

	log "github.com/sirupsen/logrus"
	"golang.org/x/sys/unix"
)

var memLockOnce sync.Once
var BTFEnabled bool

func init() {
	BTFEnabled = SupportsBTF()
}

func SupportsBTF() bool {
	_, err := os.Stat("/sys/kernel/btf/vmlinux")
	if err != nil {
		log.WithError(err).Debug("BTF not supported")
		return false
	}
	return true
}

func IncreaseLockedMemoryQuota() {
	memLockOnce.Do(func() {
		err := unix.Setrlimit(unix.RLIMIT_MEMLOCK, &unix.Rlimit{Cur: unix.RLIM_INFINITY, Max: unix.RLIM_INFINITY})
		if err != nil {
			log.WithError(err).Error("Failed to increase RLIMIT_MEMLOCK, loading BPF programs may fail")
		}
	})
}
