116 lines
2.4 KiB
Go
116 lines
2.4 KiB
Go
package main
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import (
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"net"
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"os"
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"os/signal"
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"syscall"
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"time"
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"github.com/AdguardTeam/AdGuardHome/dhcpd"
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"github.com/AdguardTeam/golibs/log"
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"github.com/krolaw/dhcp4"
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)
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func main() {
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if len(os.Args) < 2 {
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log.Printf("Usage: %s <interface name>", os.Args[0])
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os.Exit(64)
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}
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ifaceName := os.Args[1]
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present, err := dhcpd.CheckIfOtherDHCPServersPresent(ifaceName)
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if err != nil {
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panic(err)
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}
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log.Printf("Found DHCP server? %v", present)
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if present {
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log.Printf("Will not start DHCP server because there's already running one on the network")
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os.Exit(1)
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}
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iface, err := net.InterfaceByName(ifaceName)
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if err != nil {
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panic(err)
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}
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// get ipv4 address of an interface
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ifaceIPNet := getIfaceIPv4(iface)
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if ifaceIPNet == nil {
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panic(err)
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}
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// append 10 to server's IP address as start
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start := dhcp4.IPAdd(ifaceIPNet.IP, 10)
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// lease range is 100 IP's, but TODO: don't go beyond end of subnet mask
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stop := dhcp4.IPAdd(start, 100)
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server := dhcpd.Server{}
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config := dhcpd.ServerConfig{
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InterfaceName: ifaceName,
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RangeStart: start.String(),
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RangeEnd: stop.String(),
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SubnetMask: "255.255.255.0",
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GatewayIP: "192.168.7.1",
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}
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log.Printf("Starting DHCP server")
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err = server.Init(config)
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if err != nil {
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panic(err)
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}
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err = server.Start()
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if err != nil {
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panic(err)
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}
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time.Sleep(time.Second)
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log.Printf("Stopping DHCP server")
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err = server.Stop()
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if err != nil {
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panic(err)
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}
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log.Printf("Starting DHCP server")
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err = server.Start()
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if err != nil {
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panic(err)
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}
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log.Printf("Starting DHCP server while it's already running")
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err = server.Start()
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if err != nil {
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panic(err)
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}
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log.Printf("Now serving DHCP")
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signalChannel := make(chan os.Signal, 1)
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signal.Notify(signalChannel, syscall.SIGINT, syscall.SIGTERM)
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<-signalChannel
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}
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// return first IPv4 address of an interface, if there is any
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func getIfaceIPv4(iface *net.Interface) *net.IPNet {
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ifaceAddrs, err := iface.Addrs()
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if err != nil {
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panic(err)
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}
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for _, addr := range ifaceAddrs {
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ipnet, ok := addr.(*net.IPNet)
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if !ok {
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// not an IPNet, should not happen
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log.Fatalf("SHOULD NOT HAPPEN: got iface.Addrs() element %s that is not net.IPNet", addr)
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}
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if ipnet.IP.To4() == nil {
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log.Printf("Got IP that is not IPv4: %v", ipnet.IP)
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continue
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}
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log.Printf("Got IP that is IPv4: %v", ipnet.IP)
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return &net.IPNet{
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IP: ipnet.IP.To4(),
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Mask: ipnet.Mask,
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}
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}
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return nil
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}
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