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Godeps changes for kube-dns

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This commit is contained in:
Abhishek Shah
2016-05-04 16:22:06 -07:00
parent ae7809d71a
commit d2dd4911ca
39 changed files with 4162 additions and 2703 deletions
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311
vendor/github.com/miekg/dns/server.go generated vendored
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@@ -4,12 +4,17 @@ package dns
import (
"bytes"
"crypto/tls"
"io"
"net"
"sync"
"time"
)
// Maximum number of TCP queries before we close the socket.
const maxTCPQueries = 128
// Handler is implemented by any value that implements ServeDNS.
type Handler interface {
ServeDNS(w ResponseWriter, r *Msg)
}
@@ -43,9 +48,10 @@ type response struct {
tsigRequestMAC string
tsigSecret map[string]string // the tsig secrets
udp *net.UDPConn // i/o connection if UDP was used
tcp *net.TCPConn // i/o connection if TCP was used
udpSession *sessionUDP // oob data to get egress interface right
tcp net.Conn // i/o connection if TCP was used
udpSession *SessionUDP // oob data to get egress interface right
remoteAddr net.Addr // address of the client
writer Writer // writer to output the raw DNS bits
}
// ServeMux is an DNS request multiplexer. It matches the
@@ -72,12 +78,12 @@ var DefaultServeMux = NewServeMux()
// Handler object that calls f.
type HandlerFunc func(ResponseWriter, *Msg)
// ServerDNS calls f(w, r)
// ServeDNS calls f(w, r).
func (f HandlerFunc) ServeDNS(w ResponseWriter, r *Msg) {
f(w, r)
}
// FailedHandler returns a HandlerFunc that returns SERVFAIL for every request it gets.
// HandleFailed returns a HandlerFunc that returns SERVFAIL for every request it gets.
func HandleFailed(w ResponseWriter, r *Msg) {
m := new(Msg)
m.SetRcode(r, RcodeServerFailure)
@@ -87,13 +93,35 @@ func HandleFailed(w ResponseWriter, r *Msg) {
func failedHandler() Handler { return HandlerFunc(HandleFailed) }
// ListenAndServe Starts a server on addresss and network speficied. Invoke handler
// ListenAndServe Starts a server on address and network specified Invoke handler
// for incoming queries.
func ListenAndServe(addr string, network string, handler Handler) error {
server := &Server{Addr: addr, Net: network, Handler: handler}
return server.ListenAndServe()
}
// ListenAndServeTLS acts like http.ListenAndServeTLS, more information in
// http://golang.org/pkg/net/http/#ListenAndServeTLS
func ListenAndServeTLS(addr, certFile, keyFile string, handler Handler) error {
cert, err := tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
return err
}
config := tls.Config{
Certificates: []tls.Certificate{cert},
}
server := &Server{
Addr: addr,
Net: "tcp-tls",
TLSConfig: &config,
Handler: handler,
}
return server.ListenAndServe()
}
// ActivateAndServe activates a server with a listener from systemd,
// l and p should not both be non-nil.
// If both l and p are not nil only p will be used.
@@ -121,10 +149,9 @@ func (mux *ServeMux) match(q string, t uint16) Handler {
if h, ok := mux.z[string(b[:l])]; ok { // 'causes garbage, might want to change the map key
if t != TypeDS {
return h
} else {
// Continue for DS to see if we have a parent too, if so delegeate to the parent
handler = h
}
// Continue for DS to see if we have a parent too, if so delegeate to the parent
handler = h
}
off, end = NextLabel(q, off)
if end {
@@ -148,7 +175,7 @@ func (mux *ServeMux) Handle(pattern string, handler Handler) {
mux.m.Unlock()
}
// Handle adds a handler to the ServeMux for pattern.
// HandleFunc adds a handler function to the ServeMux for pattern.
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
mux.Handle(pattern, HandlerFunc(handler))
}
@@ -158,9 +185,9 @@ func (mux *ServeMux) HandleRemove(pattern string) {
if pattern == "" {
panic("dns: invalid pattern " + pattern)
}
// don't need a mutex here, because deleting is OK, even if the
// entry is note there.
mux.m.Lock()
delete(mux.z, Fqdn(pattern))
mux.m.Unlock()
}
// ServeDNS dispatches the request to the handler whose
@@ -197,14 +224,53 @@ func HandleFunc(pattern string, handler func(ResponseWriter, *Msg)) {
DefaultServeMux.HandleFunc(pattern, handler)
}
// Writer writes raw DNS messages; each call to Write should send an entire message.
type Writer interface {
io.Writer
}
// Reader reads raw DNS messages; each call to ReadTCP or ReadUDP should return an entire message.
type Reader interface {
// ReadTCP reads a raw message from a TCP connection. Implementations may alter
// connection properties, for example the read-deadline.
ReadTCP(conn net.Conn, timeout time.Duration) ([]byte, error)
// ReadUDP reads a raw message from a UDP connection. Implementations may alter
// connection properties, for example the read-deadline.
ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error)
}
// defaultReader is an adapter for the Server struct that implements the Reader interface
// using the readTCP and readUDP func of the embedded Server.
type defaultReader struct {
*Server
}
func (dr *defaultReader) ReadTCP(conn net.Conn, timeout time.Duration) ([]byte, error) {
return dr.readTCP(conn, timeout)
}
func (dr *defaultReader) ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error) {
return dr.readUDP(conn, timeout)
}
// DecorateReader is a decorator hook for extending or supplanting the functionality of a Reader.
// Implementations should never return a nil Reader.
type DecorateReader func(Reader) Reader
// DecorateWriter is a decorator hook for extending or supplanting the functionality of a Writer.
// Implementations should never return a nil Writer.
type DecorateWriter func(Writer) Writer
// A Server defines parameters for running an DNS server.
type Server struct {
// Address to listen on, ":dns" if empty.
Addr string
// if "tcp" it will invoke a TCP listener, otherwise an UDP one.
// if "tcp" or "tcp-tls" (DNS over TLS) it will invoke a TCP listener, otherwise an UDP one
Net string
// TCP Listener to use, this is to aid in systemd's socket activation.
Listener net.Listener
// TLS connection configuration
TLSConfig *tls.Config
// UDP "Listener" to use, this is to aid in systemd's socket activation.
PacketConn net.PacketConn
// Handler to invoke, dns.DefaultServeMux if nil.
@@ -221,31 +287,30 @@ type Server struct {
// Secret(s) for Tsig map[<zonename>]<base64 secret>.
TsigSecret map[string]string
// Unsafe instructs the server to disregard any sanity checks and directly hand the message to
// the handler. It will specfically not check if the query has the QR bit not set.
// the handler. It will specifically not check if the query has the QR bit not set.
Unsafe bool
// If NotifyStartedFunc is set is is called, once the server has started listening.
// If NotifyStartedFunc is set it is called once the server has started listening.
NotifyStartedFunc func()
// DecorateReader is optional, allows customization of the process that reads raw DNS messages.
DecorateReader DecorateReader
// DecorateWriter is optional, allows customization of the process that writes raw DNS messages.
DecorateWriter DecorateWriter
// For graceful shutdown.
stopUDP chan bool
stopTCP chan bool
wgUDP sync.WaitGroup
wgTCP sync.WaitGroup
// Graceful shutdown handling
// make start/shutdown not racy
lock sync.Mutex
inFlight sync.WaitGroup
lock sync.RWMutex
started bool
}
// ListenAndServe starts a nameserver on the configured address in *Server.
func (srv *Server) ListenAndServe() error {
srv.lock.Lock()
defer srv.lock.Unlock()
if srv.started {
return &Error{err: "server already started"}
}
srv.stopUDP, srv.stopTCP = make(chan bool), make(chan bool)
srv.started = true
srv.lock.Unlock()
addr := srv.Addr
if addr == "" {
addr = ":domain"
@@ -263,7 +328,30 @@ func (srv *Server) ListenAndServe() error {
if e != nil {
return e
}
return srv.serveTCP(l)
srv.Listener = l
srv.started = true
srv.lock.Unlock()
e = srv.serveTCP(l)
srv.lock.Lock() // to satisfy the defer at the top
return e
case "tcp-tls", "tcp4-tls", "tcp6-tls":
network := "tcp"
if srv.Net == "tcp4-tls" {
network = "tcp4"
} else if srv.Net == "tcp6" {
network = "tcp6"
}
l, e := tls.Listen(network, addr, srv.TLSConfig)
if e != nil {
return e
}
srv.Listener = l
srv.started = true
srv.lock.Unlock()
e = srv.serveTCP(l)
srv.lock.Lock() // to satisfy the defer at the top
return e
case "udp", "udp4", "udp6":
a, e := net.ResolveUDPAddr(srv.Net, addr)
if e != nil {
@@ -276,7 +364,12 @@ func (srv *Server) ListenAndServe() error {
if e := setUDPSocketOptions(l); e != nil {
return e
}
return srv.serveUDP(l)
srv.PacketConn = l
srv.started = true
srv.lock.Unlock()
e = srv.serveUDP(l)
srv.lock.Lock() // to satisfy the defer at the top
return e
}
return &Error{err: "bad network"}
}
@@ -285,71 +378,62 @@ func (srv *Server) ListenAndServe() error {
// configured in *Server. Its main use is to start a server from systemd.
func (srv *Server) ActivateAndServe() error {
srv.lock.Lock()
defer srv.lock.Unlock()
if srv.started {
return &Error{err: "server already started"}
}
srv.stopUDP, srv.stopTCP = make(chan bool), make(chan bool)
srv.started = true
srv.lock.Unlock()
if srv.PacketConn != nil {
pConn := srv.PacketConn
l := srv.Listener
if pConn != nil {
if srv.UDPSize == 0 {
srv.UDPSize = MinMsgSize
}
if t, ok := srv.PacketConn.(*net.UDPConn); ok {
if t, ok := pConn.(*net.UDPConn); ok {
if e := setUDPSocketOptions(t); e != nil {
return e
}
return srv.serveUDP(t)
srv.started = true
srv.lock.Unlock()
e := srv.serveUDP(t)
srv.lock.Lock() // to satisfy the defer at the top
return e
}
}
if srv.Listener != nil {
if t, ok := srv.Listener.(*net.TCPListener); ok {
return srv.serveTCP(t)
}
if l != nil {
srv.started = true
srv.lock.Unlock()
e := srv.serveTCP(l)
srv.lock.Lock() // to satisfy the defer at the top
return e
}
return &Error{err: "bad listeners"}
}
// Shutdown gracefully shuts down a server. After a call to Shutdown, ListenAndServe and
// ActivateAndServe will return. All in progress queries are completed before the server
// is taken down. If the Shutdown is taking longer than the reading timeout and error
// is taken down. If the Shutdown is taking longer than the reading timeout an error
// is returned.
func (srv *Server) Shutdown() error {
srv.lock.Lock()
if !srv.started {
srv.lock.Unlock()
return &Error{err: "server not started"}
}
srv.started = false
srv.lock.Unlock()
net, addr := srv.Net, srv.Addr
switch {
case srv.Listener != nil:
a := srv.Listener.Addr()
net, addr = a.Network(), a.String()
case srv.PacketConn != nil:
a := srv.PacketConn.LocalAddr()
net, addr = a.Network(), a.String()
if srv.PacketConn != nil {
srv.PacketConn.Close()
}
if srv.Listener != nil {
srv.Listener.Close()
}
fin := make(chan bool)
switch net {
case "tcp", "tcp4", "tcp6":
go func() {
srv.stopTCP <- true
srv.wgTCP.Wait()
fin <- true
}()
case "udp", "udp4", "udp6":
go func() {
srv.stopUDP <- true
srv.wgUDP.Wait()
fin <- true
}()
}
c := &Client{Net: net}
go c.Exchange(new(Msg), addr) // extra query to help ReadXXX loop to pass
go func() {
srv.inFlight.Wait()
fin <- true
}()
select {
case <-time.After(srv.getReadTimeout()):
@@ -369,14 +453,19 @@ func (srv *Server) getReadTimeout() time.Duration {
}
// serveTCP starts a TCP listener for the server.
// Each request is handled in a seperate goroutine.
func (srv *Server) serveTCP(l *net.TCPListener) error {
// Each request is handled in a separate goroutine.
func (srv *Server) serveTCP(l net.Listener) error {
defer l.Close()
if srv.NotifyStartedFunc != nil {
srv.NotifyStartedFunc()
}
reader := Reader(&defaultReader{srv})
if srv.DecorateReader != nil {
reader = srv.DecorateReader(reader)
}
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
@@ -384,27 +473,30 @@ func (srv *Server) serveTCP(l *net.TCPListener) error {
rtimeout := srv.getReadTimeout()
// deadline is not used here
for {
rw, e := l.AcceptTCP()
rw, e := l.Accept()
if e != nil {
continue
if neterr, ok := e.(net.Error); ok && neterr.Temporary() {
continue
}
return e
}
m, e := srv.readTCP(rw, rtimeout)
select {
case <-srv.stopTCP:
m, e := reader.ReadTCP(rw, rtimeout)
srv.lock.RLock()
if !srv.started {
srv.lock.RUnlock()
return nil
default:
}
srv.lock.RUnlock()
if e != nil {
continue
}
srv.wgTCP.Add(1)
srv.inFlight.Add(1)
go srv.serve(rw.RemoteAddr(), handler, m, nil, nil, rw)
}
panic("dns: not reached")
}
// serveUDP starts a UDP listener for the server.
// Each request is handled in a seperate goroutine.
// Each request is handled in a separate goroutine.
func (srv *Server) serveUDP(l *net.UDPConn) error {
defer l.Close()
@@ -412,6 +504,11 @@ func (srv *Server) serveUDP(l *net.UDPConn) error {
srv.NotifyStartedFunc()
}
reader := Reader(&defaultReader{srv})
if srv.DecorateReader != nil {
reader = srv.DecorateReader(reader)
}
handler := srv.Handler
if handler == nil {
handler = DefaultServeMux
@@ -419,35 +516,39 @@ func (srv *Server) serveUDP(l *net.UDPConn) error {
rtimeout := srv.getReadTimeout()
// deadline is not used here
for {
m, s, e := srv.readUDP(l, rtimeout)
select {
case <-srv.stopUDP:
m, s, e := reader.ReadUDP(l, rtimeout)
srv.lock.RLock()
if !srv.started {
srv.lock.RUnlock()
return nil
default:
}
srv.lock.RUnlock()
if e != nil {
continue
}
srv.wgUDP.Add(1)
srv.inFlight.Add(1)
go srv.serve(s.RemoteAddr(), handler, m, l, s, nil)
}
panic("dns: not reached")
}
// Serve a new connection.
func (srv *Server) serve(a net.Addr, h Handler, m []byte, u *net.UDPConn, s *sessionUDP, t *net.TCPConn) {
func (srv *Server) serve(a net.Addr, h Handler, m []byte, u *net.UDPConn, s *SessionUDP, t net.Conn) {
defer srv.inFlight.Done()
w := &response{tsigSecret: srv.TsigSecret, udp: u, tcp: t, remoteAddr: a, udpSession: s}
q := 0
defer func() {
if u != nil {
srv.wgUDP.Done()
}
if t != nil {
srv.wgTCP.Done()
}
}()
if srv.DecorateWriter != nil {
w.writer = srv.DecorateWriter(w)
} else {
w.writer = w
}
q := 0 // counter for the amount of TCP queries we get
reader := Reader(&defaultReader{srv})
if srv.DecorateReader != nil {
reader = srv.DecorateReader(reader)
}
Redo:
// Ideally we want use isMsg here before we allocate memory to actually parse the packet.
req := new(Msg)
err := req.Unpack(m)
if err != nil { // Send a FormatError back
@@ -475,6 +576,15 @@ Redo:
h.ServeDNS(w, req) // Writes back to the client
Exit:
if w.tcp == nil {
return
}
// TODO(miek): make this number configurable?
if q > maxTCPQueries { // close socket after this many queries
w.Close()
return
}
if w.hijacked {
return // client calls Close()
}
@@ -486,21 +596,16 @@ Exit:
if srv.IdleTimeout != nil {
idleTimeout = srv.IdleTimeout()
}
m, e := srv.readTCP(w.tcp, idleTimeout)
m, e := reader.ReadTCP(w.tcp, idleTimeout)
if e == nil {
q++
// TODO(miek): make this number configurable?
if q > 128 { // close socket after this many queries
w.Close()
return
}
goto Redo
}
w.Close()
return
}
func (srv *Server) readTCP(conn *net.TCPConn, timeout time.Duration) ([]byte, error) {
func (srv *Server) readTCP(conn net.Conn, timeout time.Duration) ([]byte, error) {
conn.SetReadDeadline(time.Now().Add(timeout))
l := make([]byte, 2)
n, err := conn.Read(l)
@@ -535,10 +640,10 @@ func (srv *Server) readTCP(conn *net.TCPConn, timeout time.Duration) ([]byte, er
return m, nil
}
func (srv *Server) readUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *sessionUDP, error) {
func (srv *Server) readUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error) {
conn.SetReadDeadline(time.Now().Add(timeout))
m := make([]byte, srv.UDPSize)
n, s, e := readFromSessionUDP(conn, m)
n, s, e := ReadFromSessionUDP(conn, m)
if e != nil || n == 0 {
if e != nil {
return nil, nil, e
@@ -558,7 +663,7 @@ func (w *response) WriteMsg(m *Msg) (err error) {
if err != nil {
return err
}
_, err = w.Write(data)
_, err = w.writer.Write(data)
return err
}
}
@@ -566,7 +671,7 @@ func (w *response) WriteMsg(m *Msg) (err error) {
if err != nil {
return err
}
_, err = w.Write(data)
_, err = w.writer.Write(data)
return err
}
@@ -574,7 +679,7 @@ func (w *response) WriteMsg(m *Msg) (err error) {
func (w *response) Write(m []byte) (int, error) {
switch {
case w.udp != nil:
n, err := writeToSessionUDP(w.udp, m, w.udpSession)
n, err := WriteToSessionUDP(w.udp, m, w.udpSession)
return n, err
case w.tcp != nil:
lm := len(m)