59 lines
1.1 KiB
Go
59 lines
1.1 KiB
Go
// Binary dnsd answers DNS requests by forwarding or consulting DHCP leases.
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package main
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import (
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"encoding/json"
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"flag"
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"io/ioutil"
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"log"
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"os"
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"os/signal"
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"syscall"
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"router7/internal/dhcp4d"
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"router7/internal/dns"
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"router7/internal/netconfig"
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)
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func logic() error {
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// TODO: set correct upstream DNS resolver(s)
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ip, err := netconfig.LinkAddress("/perm", "lan0")
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if err != nil {
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return err
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}
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srv := dns.NewServer(ip.String()+":53", "lan")
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readLeases := func() error {
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b, err := ioutil.ReadFile("/perm/dhcp4d/leases.json")
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if err != nil {
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return err
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}
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var leases []dhcp4d.Lease
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if err := json.Unmarshal(b, &leases); err != nil {
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return err
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}
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srv.SetLeases(leases)
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return nil
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}
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if err := readLeases(); err != nil {
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log.Printf("cannot resolve DHCP hostnames: %v", err)
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}
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ch := make(chan os.Signal, 1)
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signal.Notify(ch, syscall.SIGUSR1)
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go func() {
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for range ch {
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if err := readLeases(); err != nil {
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log.Printf("readLeases: %v", err)
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}
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}
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}()
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return srv.ListenAndServe()
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}
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func main() {
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// TODO: drop privileges, run as separate uid?
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flag.Parse()
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if err := logic(); err != nil {
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log.Fatal(err)
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}
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}
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