57 lines
1007 B
Go
57 lines
1007 B
Go
// ntp is a minimal NTP client for gokrazy.
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package main
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import (
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"log"
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"math/rand"
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"os"
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"syscall"
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"time"
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"github.com/beevik/ntp"
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)
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func set(rtc *os.File) error {
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r, err := ntp.Query("0.gokrazy.pool.ntp.org")
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if err != nil {
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return err
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}
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tv := syscall.NsecToTimeval(r.Time.UnixNano())
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if err := syscall.Settimeofday(&tv); err != nil {
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return err
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}
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log.Printf("clock set to %v", r.Time)
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if rtc == nil {
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return nil
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}
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return setRTC(rtc, r.Time.UTC())
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}
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func main() {
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log.SetFlags(log.LstdFlags | log.Lshortfile)
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var rtc *os.File
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var err error
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if os.Getenv("NTP_PRIVILEGES_DROPPED") == "1" {
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if os.Getenv("NTP_RTC") == "1" {
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rtc = os.NewFile(3, "/dev/rtc0")
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}
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} else {
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rtc, err = os.Open("/dev/rtc0")
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if err != nil && !os.IsNotExist(err) {
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log.Fatal(err)
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}
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}
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mustDropPrivileges(rtc)
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for {
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if err := set(rtc); err != nil {
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log.Fatalf("setting time failed: %v", err)
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}
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time.Sleep(1*time.Hour + time.Duration(rand.Int63n(250))*time.Millisecond)
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}
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}
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