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34 lines
642 B
Go
34 lines
642 B
Go
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// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package tcpinfo
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import (
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"net"
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"time"
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"golang.org/x/sys/unix"
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)
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func rttImpl(conn *net.TCPConn) (time.Duration, error) {
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rawConn, err := conn.SyscallConn()
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if err != nil {
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return 0, err
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}
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var (
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tcpInfo *unix.TCPConnectionInfo
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sysErr error
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)
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err = rawConn.Control(func(fd uintptr) {
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tcpInfo, sysErr = unix.GetsockoptTCPConnectionInfo(int(fd), unix.IPPROTO_TCP, unix.TCP_CONNECTION_INFO)
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})
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if err != nil {
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return 0, err
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} else if sysErr != nil {
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return 0, sysErr
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}
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return time.Duration(tcpInfo.Rttcur) * time.Millisecond, nil
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}
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