87 lines
1.6 KiB
Go
87 lines
1.6 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package derp
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import (
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"context"
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"crypto/tls"
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"net"
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"time"
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"tailscale.com/net/tcpinfo"
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)
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func (c *sclient) statsLoop(ctx context.Context) error {
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// Get the RTT initially to verify it's supported.
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conn := c.tcpConn()
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if conn == nil {
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c.s.tcpRtt.Add("non-tcp", 1)
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return nil
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}
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if _, err := tcpinfo.RTT(conn); err != nil {
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c.logf("error fetching initial RTT: %v", err)
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c.s.tcpRtt.Add("error", 1)
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return nil
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}
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const statsInterval = 10 * time.Second
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ticker, tickerChannel := c.s.clock.NewTicker(statsInterval)
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defer ticker.Stop()
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statsLoop:
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for {
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select {
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case <-tickerChannel:
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rtt, err := tcpinfo.RTT(conn)
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if err != nil {
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continue statsLoop
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}
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// TODO(andrew): more metrics?
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c.s.tcpRtt.Add(durationToLabel(rtt), 1)
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case <-ctx.Done():
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return ctx.Err()
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}
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}
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}
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// tcpConn attempts to get the underlying *net.TCPConn from this client's
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// Conn; if it cannot, then it will return nil.
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func (c *sclient) tcpConn() *net.TCPConn {
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nc := c.nc
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for {
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switch v := nc.(type) {
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case *net.TCPConn:
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return v
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case *tls.Conn:
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nc = v.NetConn()
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default:
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return nil
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}
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}
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}
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func durationToLabel(dur time.Duration) string {
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switch {
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case dur <= 10*time.Millisecond:
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return "10ms"
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case dur <= 20*time.Millisecond:
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return "20ms"
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case dur <= 50*time.Millisecond:
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return "50ms"
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case dur <= 100*time.Millisecond:
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return "100ms"
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case dur <= 150*time.Millisecond:
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return "150ms"
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case dur <= 250*time.Millisecond:
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return "250ms"
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case dur <= 500*time.Millisecond:
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return "500ms"
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default:
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return "inf"
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}
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}
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