func main() {
fixListenPid()
pc, _ := activation.PacketConns(false)
if len(pc) == 0 {
panic("No packetConns")
}
if os.Getenv("LISTEN_PID") == "" || os.Getenv("LISTEN_FDS") == "" {
panic("Should not unset envs")
}
pc, err := activation.PacketConns(true)
if err != nil {
panic(err)
}
if os.Getenv("LISTEN_PID") != "" || os.Getenv("LISTEN_FDS") != "" {
panic("Can not unset envs")
}
udp1, ok := pc[0].(*net.UDPConn)
if !ok {
panic("packetConn 1 not UDP")
}
udp2, ok := pc[1].(*net.UDPConn)
if !ok {
panic("packetConn 2 not UDP")
}
_, addr1, err := udp1.ReadFromUDP(nil)
if err != nil {
panic(err)
}
_, addr2, err := udp2.ReadFromUDP(nil)
if err != nil {
panic(err)
}
// Write out the expected strings to the two pipes
_, err = udp1.WriteToUDP([]byte("Hello world"), addr1)
if err != nil {
panic(err)
}
_, err = udp2.WriteToUDP([]byte("Goodbye world"), addr2)
if err != nil {
panic(err)
}
return
}
func (s *Server) systemdServe() {
// We will usually have at least one TCP socket and one UDP socket.
// PacketConns are UDP sockets, Listeners are TCP sockets.
// To make things more annoying, both can (and usually will) have nil
// entries for the file descriptors that don't match.
pconns, err := activation.PacketConns(false)
if err != nil {
glog.Fatalf("Error getting systemd packet conns: %v", err)
}
listeners, err := activation.Listeners(false)
if err != nil {
glog.Fatalf("Error getting systemd listeners: %v", err)
}
var wg sync.WaitGroup
for _, pconn := range pconns {
if pconn == nil {
continue
}
wg.Add(1)
go func(c net.PacketConn) {
defer wg.Done()
glog.Infof("Activate on packet connection (UDP)")
err := dns.ActivateAndServe(nil, c, dns.HandlerFunc(s.Handler))
glog.Fatalf("Exiting UDP listener: %v", err)
}(pconn)
}
for _, lis := range listeners {
if lis == nil {
continue
}
wg.Add(1)
go func(l net.Listener) {
defer wg.Done()
glog.Infof("Activate on listening socket (TCP)")
err := dns.ActivateAndServe(l, nil, dns.HandlerFunc(s.Handler))
glog.Fatalf("Exiting TCP listener: %v", err)
}(lis)
}
wg.Wait()
// We should only get here if there were no useful sockets.
glog.Fatalf("No systemd sockets, did you forget the .socket?")
}
// Run is a blocking operation that starts the server listening on the DNS ports.
func (s *server) Run() error {
mux := dns.NewServeMux()
mux.Handle(".", s)
dnsReadyMsg := func(addr, net string) {
if s.config.DNSSEC == "" {
log.Printf("skydns: ready for queries on %s for %s://%s [rcache %d]", s.config.Domain, net, addr, s.config.RCache)
} else {
log.Printf("skydns: ready for queries on %s for %s://%s [rcache %d], signing with %s [scache %d]", s.config.Domain, net, addr, s.config.RCache, s.config.DNSSEC, s.config.SCache)
}
}
if s.config.Systemd {
packetConns, err := activation.PacketConns(false)
if err != nil {
return err
}
listeners, err := activation.Listeners(true)
if err != nil {
return err
}
if len(packetConns) == 0 && len(listeners) == 0 {
return fmt.Errorf("no UDP or TCP sockets supplied by systemd")
}
for _, p := range packetConns {
if u, ok := p.(*net.UDPConn); ok {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ActivateAndServe(nil, u, mux); err != nil {
log.Fatalf("skydns: %s", err)
}
}()
dnsReadyMsg(u.LocalAddr().String(), "udp")
}
}
for _, l := range listeners {
if t, ok := l.(*net.TCPListener); ok {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ActivateAndServe(t, nil, mux); err != nil {
log.Fatalf("skydns: %s", err)
}
}()
dnsReadyMsg(t.Addr().String(), "tcp")
}
}
} else {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ListenAndServe(s.config.DnsAddr, "tcp", mux); err != nil {
log.Fatalf("skydns: %s", err)
}
}()
dnsReadyMsg(s.config.DnsAddr, "tcp")
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ListenAndServe(s.config.DnsAddr, "udp", mux); err != nil {
log.Fatalf("skydns: %s", err)
}
}()
dnsReadyMsg(s.config.DnsAddr, "udp")
}
s.group.Wait()
return nil
}
// Run is a blocking operation that starts the server listening on the DNS ports.
func (s *server) Run() error {
mux := dns.NewServeMux()
mux.Handle(".", s)
dnsReadyMsg := func(addr, net string) {
rCacheState := "disabled"
if s.config.RCache > 0 {
rCacheState = fmt.Sprintf("capacity: %d", s.config.RCache)
}
log.Infof("Ready for queries on %s://%s [cache: %s]", net, addr, rCacheState)
}
if s.config.Systemd {
packetConns, err := activation.PacketConns(false)
if err != nil {
return err
}
listeners, err := activation.Listeners(true)
if err != nil {
return err
}
if len(packetConns) == 0 && len(listeners) == 0 {
return fmt.Errorf("No UDP or TCP sockets supplied by systemd")
}
for _, p := range packetConns {
if u, ok := p.(*net.UDPConn); ok {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ActivateAndServe(nil, u, mux); err != nil {
log.Fatalf("%s", err)
}
}()
dnsReadyMsg(u.LocalAddr().String(), "udp")
}
}
for _, l := range listeners {
if t, ok := l.(*net.TCPListener); ok {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ActivateAndServe(t, nil, mux); err != nil {
log.Fatalf("%s", err)
}
}()
dnsReadyMsg(t.Addr().String(), "tcp")
}
}
} else {
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ListenAndServe(s.config.DnsAddr, "tcp", mux); err != nil {
log.Fatalf("%s", err)
}
}()
dnsReadyMsg(s.config.DnsAddr, "tcp")
s.group.Add(1)
go func() {
defer s.group.Done()
if err := dns.ListenAndServe(s.config.DnsAddr, "udp", mux); err != nil {
log.Fatalf("%s", err)
}
}()
dnsReadyMsg(s.config.DnsAddr, "udp")
}
s.group.Wait()
return nil
}