31 lines
743 B
Go
31 lines
743 B
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build linux || freebsd || openbsd
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package dns
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import (
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"bytes"
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"os/exec"
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)
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func resolvconfStyle() string {
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if _, err := exec.LookPath("resolvconf"); err != nil {
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return ""
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}
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output, err := exec.Command("resolvconf", "--version").CombinedOutput()
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if err != nil {
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// Debian resolvconf doesn't understand --version, and
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// exits with a specific error code.
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if exitErr, ok := err.(*exec.ExitError); ok && exitErr.ExitCode() == 99 {
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return "debian"
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}
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}
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if bytes.HasPrefix(output, []byte("Debian resolvconf")) {
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return "debian"
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}
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// Treat everything else as openresolv, by far the more popular implementation.
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return "openresolv"
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}
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