tailscale/util/linuxfw/helpers.go

38 lines
741 B
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux
package linuxfw
import (
"encoding/hex"
"fmt"
"strings"
"unicode"
)
func formatMaybePrintable(b []byte) string {
// Remove a single trailing null, if any
if len(b) > 0 && b[len(b)-1] == 0 {
b = b[:len(b)-1]
}
nonprintable := strings.IndexFunc(string(b), func(r rune) bool {
return r > unicode.MaxASCII || !unicode.IsPrint(r)
})
if nonprintable >= 0 {
return "<hex>" + hex.EncodeToString(b)
}
return string(b)
}
func formatPortRange(r [2]uint16) string {
if r == [2]uint16{0, 65535} {
return fmt.Sprintf(`any`)
} else if r[0] == r[1] {
return fmt.Sprintf(`%d`, r[0])
}
return fmt.Sprintf(`%d-%d`, r[0], r[1])
}