You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: os_linux.go
    path of file: ./repos/AdGuardHome/internal/aghos
    
    the code of the file until where you have to start completion: //go:build linux

package aghos

import (
	"io"
	"os"
	"syscall"

	"github.com/AdguardTeam/golibs/osutil"
	"github.com/AdguardTeam/golibs/stringutil"
)

func setRlimit(val uint64) (err error) {
	var rlim syscall.Rlimit
	rlim.Max = val
	rlim.Cur = val

	return syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlim)
}

func haveAdminRight
    
func isOpenWrt() (ok bool) {
	const etcReleasePattern = "etc/*release*"

	var err error
	ok, err = FileWalker(func(r io.Reader) (_ []string, cont bool, err error) {
		const osNameData = "openwrt"

		// This use of ReadAll is now safe, because FileWalker's Walk()
		// have limited r.
		var data []byte
		data, err = io.ReadAll(r)
		if err != nil {
			return nil, false, err
		}

		return nil, !stringutil.ContainsFold(string(data), osNameData), nil
	}).Walk(osutil.RootDirFS(), etcReleasePattern)

	return err == nil && ok
}