mirror of https://github.com/k3s-io/k3s
475 lines
14 KiB
Go
475 lines
14 KiB
Go
// Copyright 2017 Google Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
// Package tcpproxy lets users build TCP proxies, optionally making
|
|
// routing decisions based on HTTP/1 Host headers and the SNI hostname
|
|
// in TLS connections.
|
|
//
|
|
// Typical usage:
|
|
//
|
|
// var p tcpproxy.Proxy
|
|
// p.AddHTTPHostRoute(":80", "foo.com", tcpproxy.To("10.0.0.1:8081"))
|
|
// p.AddHTTPHostRoute(":80", "bar.com", tcpproxy.To("10.0.0.2:8082"))
|
|
// p.AddRoute(":80", tcpproxy.To("10.0.0.1:8081")) // fallback
|
|
// p.AddSNIRoute(":443", "foo.com", tcpproxy.To("10.0.0.1:4431"))
|
|
// p.AddSNIRoute(":443", "bar.com", tcpproxy.To("10.0.0.2:4432"))
|
|
// p.AddRoute(":443", tcpproxy.To("10.0.0.1:4431")) // fallback
|
|
// log.Fatal(p.Run())
|
|
//
|
|
// Calling Run (or Start) on a proxy also starts all the necessary
|
|
// listeners.
|
|
//
|
|
// For each accepted connection, the rules for that ipPort are
|
|
// matched, in order. If one matches (currently HTTP Host, SNI, or
|
|
// always), then the connection is handed to the target.
|
|
//
|
|
// The two predefined Target implementations are:
|
|
//
|
|
// 1) DialProxy, proxying to another address (use the To func to return a
|
|
// DialProxy value),
|
|
//
|
|
// 2) TargetListener, making the matched connection available via a
|
|
// net.Listener.Accept call.
|
|
//
|
|
// But Target is an interface, so you can also write your own.
|
|
//
|
|
// Note that tcpproxy does not do any TLS encryption or decryption. It
|
|
// only (via DialProxy) copies bytes around. The SNI hostname in the TLS
|
|
// header is unencrypted, for better or worse.
|
|
//
|
|
// This package makes no API stability promises. If you depend on it,
|
|
// vendor it.
|
|
package tcpproxy
|
|
|
|
import (
|
|
"bufio"
|
|
"context"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"log"
|
|
"net"
|
|
"time"
|
|
)
|
|
|
|
// Proxy is a proxy. Its zero value is a valid proxy that does
|
|
// nothing. Call methods to add routes before calling Start or Run.
|
|
//
|
|
// The order that routes are added in matters; each is matched in the order
|
|
// registered.
|
|
type Proxy struct {
|
|
configs map[string]*config // ip:port => config
|
|
|
|
lns []net.Listener
|
|
donec chan struct{} // closed before err
|
|
err error // any error from listening
|
|
|
|
// ListenFunc optionally specifies an alternate listen
|
|
// function. If nil, net.Dial is used.
|
|
// The provided net is always "tcp".
|
|
ListenFunc func(net, laddr string) (net.Listener, error)
|
|
}
|
|
|
|
// Matcher reports whether hostname matches the Matcher's criteria.
|
|
type Matcher func(ctx context.Context, hostname string) bool
|
|
|
|
// equals is a trivial Matcher that implements string equality.
|
|
func equals(want string) Matcher {
|
|
return func(_ context.Context, got string) bool {
|
|
return want == got
|
|
}
|
|
}
|
|
|
|
// config contains the proxying state for one listener.
|
|
type config struct {
|
|
routes []route
|
|
acmeTargets []Target // accumulates targets that should be probed for acme.
|
|
stopACME bool // if true, AddSNIRoute doesn't add targets to acmeTargets.
|
|
}
|
|
|
|
// A route matches a connection to a target.
|
|
type route interface {
|
|
// match examines the initial bytes of a connection, looking for a
|
|
// match. If a match is found, match returns a non-nil Target to
|
|
// which the stream should be proxied. match returns nil if the
|
|
// connection doesn't match.
|
|
//
|
|
// match must not consume bytes from the given bufio.Reader, it
|
|
// can only Peek.
|
|
//
|
|
// If an sni or host header was parsed successfully, that will be
|
|
// returned as the second parameter.
|
|
match(*bufio.Reader) (Target, string)
|
|
}
|
|
|
|
func (p *Proxy) netListen() func(net, laddr string) (net.Listener, error) {
|
|
if p.ListenFunc != nil {
|
|
return p.ListenFunc
|
|
}
|
|
return net.Listen
|
|
}
|
|
|
|
func (p *Proxy) configFor(ipPort string) *config {
|
|
if p.configs == nil {
|
|
p.configs = make(map[string]*config)
|
|
}
|
|
if p.configs[ipPort] == nil {
|
|
p.configs[ipPort] = &config{}
|
|
}
|
|
return p.configs[ipPort]
|
|
}
|
|
|
|
func (p *Proxy) addRoute(ipPort string, r route) {
|
|
cfg := p.configFor(ipPort)
|
|
cfg.routes = append(cfg.routes, r)
|
|
}
|
|
|
|
// AddRoute appends an always-matching route to the ipPort listener,
|
|
// directing any connection to dest.
|
|
//
|
|
// This is generally used as either the only rule (for simple TCP
|
|
// proxies), or as the final fallback rule for an ipPort.
|
|
//
|
|
// The ipPort is any valid net.Listen TCP address.
|
|
func (p *Proxy) AddRoute(ipPort string, dest Target) {
|
|
p.addRoute(ipPort, fixedTarget{dest})
|
|
}
|
|
|
|
type fixedTarget struct {
|
|
t Target
|
|
}
|
|
|
|
func (m fixedTarget) match(*bufio.Reader) (Target, string) { return m.t, "" }
|
|
|
|
// Run is calls Start, and then Wait.
|
|
//
|
|
// It blocks until there's an error. The return value is always
|
|
// non-nil.
|
|
func (p *Proxy) Run() error {
|
|
if err := p.Start(); err != nil {
|
|
return err
|
|
}
|
|
return p.Wait()
|
|
}
|
|
|
|
// Wait waits for the Proxy to finish running. Currently this can only
|
|
// happen if a Listener is closed, or Close is called on the proxy.
|
|
//
|
|
// It is only valid to call Wait after a successful call to Start.
|
|
func (p *Proxy) Wait() error {
|
|
<-p.donec
|
|
return p.err
|
|
}
|
|
|
|
// Close closes all the proxy's self-opened listeners.
|
|
func (p *Proxy) Close() error {
|
|
for _, c := range p.lns {
|
|
c.Close()
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Start creates a TCP listener for each unique ipPort from the
|
|
// previously created routes and starts the proxy. It returns any
|
|
// error from starting listeners.
|
|
//
|
|
// If it returns a non-nil error, any successfully opened listeners
|
|
// are closed.
|
|
func (p *Proxy) Start() error {
|
|
if p.donec != nil {
|
|
return errors.New("already started")
|
|
}
|
|
p.donec = make(chan struct{})
|
|
errc := make(chan error, len(p.configs))
|
|
p.lns = make([]net.Listener, 0, len(p.configs))
|
|
for ipPort, config := range p.configs {
|
|
ln, err := p.netListen()("tcp", ipPort)
|
|
if err != nil {
|
|
p.Close()
|
|
return err
|
|
}
|
|
p.lns = append(p.lns, ln)
|
|
go p.serveListener(errc, ln, config.routes)
|
|
}
|
|
go p.awaitFirstError(errc)
|
|
return nil
|
|
}
|
|
|
|
func (p *Proxy) awaitFirstError(errc <-chan error) {
|
|
p.err = <-errc
|
|
close(p.donec)
|
|
}
|
|
|
|
func (p *Proxy) serveListener(ret chan<- error, ln net.Listener, routes []route) {
|
|
for {
|
|
c, err := ln.Accept()
|
|
if err != nil {
|
|
ret <- err
|
|
return
|
|
}
|
|
go p.serveConn(c, routes)
|
|
}
|
|
}
|
|
|
|
// serveConn runs in its own goroutine and matches c against routes.
|
|
// It returns whether it matched purely for testing.
|
|
func (p *Proxy) serveConn(c net.Conn, routes []route) bool {
|
|
br := bufio.NewReader(c)
|
|
for _, route := range routes {
|
|
if target, hostName := route.match(br); target != nil {
|
|
if n := br.Buffered(); n > 0 {
|
|
peeked, _ := br.Peek(br.Buffered())
|
|
c = &Conn{
|
|
HostName: hostName,
|
|
Peeked: peeked,
|
|
Conn: c,
|
|
}
|
|
}
|
|
target.HandleConn(c)
|
|
return true
|
|
}
|
|
}
|
|
// TODO: hook for this?
|
|
log.Printf("tcpproxy: no routes matched conn %v/%v; closing", c.RemoteAddr().String(), c.LocalAddr().String())
|
|
c.Close()
|
|
return false
|
|
}
|
|
|
|
// Conn is an incoming connection that has had some bytes read from it
|
|
// to determine how to route the connection. The Read method stitches
|
|
// the peeked bytes and unread bytes back together.
|
|
type Conn struct {
|
|
// HostName is the hostname field that was sent to the request router.
|
|
// In the case of TLS, this is the SNI header, in the case of HTTPHost
|
|
// route, it will be the host header. In the case of a fixed
|
|
// route, i.e. those created with AddRoute(), this will always be
|
|
// empty. This can be useful in the case where further routing decisions
|
|
// need to be made in the Target impementation.
|
|
HostName string
|
|
|
|
// Peeked are the bytes that have been read from Conn for the
|
|
// purposes of route matching, but have not yet been consumed
|
|
// by Read calls. It set to nil by Read when fully consumed.
|
|
Peeked []byte
|
|
|
|
// Conn is the underlying connection.
|
|
// It can be type asserted against *net.TCPConn or other types
|
|
// as needed. It should not be read from directly unless
|
|
// Peeked is nil.
|
|
net.Conn
|
|
}
|
|
|
|
func (c *Conn) Read(p []byte) (n int, err error) {
|
|
if len(c.Peeked) > 0 {
|
|
n = copy(p, c.Peeked)
|
|
c.Peeked = c.Peeked[n:]
|
|
if len(c.Peeked) == 0 {
|
|
c.Peeked = nil
|
|
}
|
|
return n, nil
|
|
}
|
|
return c.Conn.Read(p)
|
|
}
|
|
|
|
// Target is what an incoming matched connection is sent to.
|
|
type Target interface {
|
|
// HandleConn is called when an incoming connection is
|
|
// matched. After the call to HandleConn, the tcpproxy
|
|
// package never touches the conn again. Implementations are
|
|
// responsible for closing the connection when needed.
|
|
//
|
|
// The concrete type of conn will be of type *Conn if any
|
|
// bytes have been consumed for the purposes of route
|
|
// matching.
|
|
HandleConn(net.Conn)
|
|
}
|
|
|
|
// To is shorthand way of writing &tlsproxy.DialProxy{Addr: addr}.
|
|
func To(addr string) *DialProxy {
|
|
return &DialProxy{Addr: addr}
|
|
}
|
|
|
|
// DialProxy implements Target by dialing a new connection to Addr
|
|
// and then proxying data back and forth.
|
|
//
|
|
// The To func is a shorthand way of creating a DialProxy.
|
|
type DialProxy struct {
|
|
// Addr is the TCP address to proxy to.
|
|
Addr string
|
|
|
|
// KeepAlivePeriod sets the period between TCP keep alives.
|
|
// If zero, a default is used. To disable, use a negative number.
|
|
// The keep-alive is used for both the client connection and
|
|
KeepAlivePeriod time.Duration
|
|
|
|
// DialTimeout optionally specifies a dial timeout.
|
|
// If zero, a default is used.
|
|
// If negative, the timeout is disabled.
|
|
DialTimeout time.Duration
|
|
|
|
// DialContext optionally specifies an alternate dial function
|
|
// for TCP targets. If nil, the standard
|
|
// net.Dialer.DialContext method is used.
|
|
DialContext func(ctx context.Context, network, address string) (net.Conn, error)
|
|
|
|
// OnDialError optionally specifies an alternate way to handle errors dialing Addr.
|
|
// If nil, the error is logged and src is closed.
|
|
// If non-nil, src is not closed automatically.
|
|
OnDialError func(src net.Conn, dstDialErr error)
|
|
|
|
// ProxyProtocolVersion optionally specifies the version of
|
|
// HAProxy's PROXY protocol to use. The PROXY protocol provides
|
|
// connection metadata to the DialProxy target, via a header
|
|
// inserted ahead of the client's traffic. The DialProxy target
|
|
// must explicitly support and expect the PROXY header; there is
|
|
// no graceful downgrade.
|
|
// If zero, no PROXY header is sent. Currently, version 1 is supported.
|
|
ProxyProtocolVersion int
|
|
}
|
|
|
|
// UnderlyingConn returns c.Conn if c of type *Conn,
|
|
// otherwise it returns c.
|
|
func UnderlyingConn(c net.Conn) net.Conn {
|
|
if wrap, ok := c.(*Conn); ok {
|
|
return wrap.Conn
|
|
}
|
|
return c
|
|
}
|
|
|
|
func goCloseConn(c net.Conn) { go c.Close() }
|
|
|
|
// HandleConn implements the Target interface.
|
|
func (dp *DialProxy) HandleConn(src net.Conn) {
|
|
ctx := context.Background()
|
|
var cancel context.CancelFunc
|
|
if dp.DialTimeout >= 0 {
|
|
ctx, cancel = context.WithTimeout(ctx, dp.dialTimeout())
|
|
}
|
|
dst, err := dp.dialContext()(ctx, "tcp", dp.Addr)
|
|
if cancel != nil {
|
|
cancel()
|
|
}
|
|
if err != nil {
|
|
dp.onDialError()(src, err)
|
|
return
|
|
}
|
|
defer goCloseConn(dst)
|
|
|
|
if err = dp.sendProxyHeader(dst, src); err != nil {
|
|
dp.onDialError()(src, err)
|
|
return
|
|
}
|
|
defer goCloseConn(src)
|
|
|
|
if ka := dp.keepAlivePeriod(); ka > 0 {
|
|
if c, ok := UnderlyingConn(src).(*net.TCPConn); ok {
|
|
c.SetKeepAlive(true)
|
|
c.SetKeepAlivePeriod(ka)
|
|
}
|
|
if c, ok := dst.(*net.TCPConn); ok {
|
|
c.SetKeepAlive(true)
|
|
c.SetKeepAlivePeriod(ka)
|
|
}
|
|
}
|
|
|
|
errc := make(chan error, 1)
|
|
go proxyCopy(errc, src, dst)
|
|
go proxyCopy(errc, dst, src)
|
|
<-errc
|
|
}
|
|
|
|
func (dp *DialProxy) sendProxyHeader(w io.Writer, src net.Conn) error {
|
|
switch dp.ProxyProtocolVersion {
|
|
case 0:
|
|
return nil
|
|
case 1:
|
|
var srcAddr, dstAddr *net.TCPAddr
|
|
if a, ok := src.RemoteAddr().(*net.TCPAddr); ok {
|
|
srcAddr = a
|
|
}
|
|
if a, ok := src.LocalAddr().(*net.TCPAddr); ok {
|
|
dstAddr = a
|
|
}
|
|
|
|
if srcAddr == nil || dstAddr == nil {
|
|
_, err := io.WriteString(w, "PROXY UNKNOWN\r\n")
|
|
return err
|
|
}
|
|
|
|
family := "TCP4"
|
|
if srcAddr.IP.To4() == nil {
|
|
family = "TCP6"
|
|
}
|
|
_, err := fmt.Fprintf(w, "PROXY %s %s %d %s %d\r\n", family, srcAddr.IP, srcAddr.Port, dstAddr.IP, dstAddr.Port)
|
|
return err
|
|
default:
|
|
return fmt.Errorf("PROXY protocol version %d not supported", dp.ProxyProtocolVersion)
|
|
}
|
|
}
|
|
|
|
// proxyCopy is the function that copies bytes around.
|
|
// It's a named function instead of a func literal so users get
|
|
// named goroutines in debug goroutine stack dumps.
|
|
func proxyCopy(errc chan<- error, dst, src net.Conn) {
|
|
// Before we unwrap src and/or dst, copy any buffered data.
|
|
if wc, ok := src.(*Conn); ok && len(wc.Peeked) > 0 {
|
|
if _, err := dst.Write(wc.Peeked); err != nil {
|
|
errc <- err
|
|
return
|
|
}
|
|
wc.Peeked = nil
|
|
}
|
|
|
|
// Unwrap the src and dst from *Conn to *net.TCPConn so Go
|
|
// 1.11's splice optimization kicks in.
|
|
src = UnderlyingConn(src)
|
|
dst = UnderlyingConn(dst)
|
|
|
|
_, err := io.Copy(dst, src)
|
|
errc <- err
|
|
}
|
|
|
|
func (dp *DialProxy) keepAlivePeriod() time.Duration {
|
|
if dp.KeepAlivePeriod != 0 {
|
|
return dp.KeepAlivePeriod
|
|
}
|
|
return time.Minute
|
|
}
|
|
|
|
func (dp *DialProxy) dialTimeout() time.Duration {
|
|
if dp.DialTimeout > 0 {
|
|
return dp.DialTimeout
|
|
}
|
|
return 10 * time.Second
|
|
}
|
|
|
|
var defaultDialer = new(net.Dialer)
|
|
|
|
func (dp *DialProxy) dialContext() func(ctx context.Context, network, address string) (net.Conn, error) {
|
|
if dp.DialContext != nil {
|
|
return dp.DialContext
|
|
}
|
|
return defaultDialer.DialContext
|
|
}
|
|
|
|
func (dp *DialProxy) onDialError() func(src net.Conn, dstDialErr error) {
|
|
if dp.OnDialError != nil {
|
|
return dp.OnDialError
|
|
}
|
|
return func(src net.Conn, dstDialErr error) {
|
|
log.Printf("tcpproxy: for incoming conn %v, error dialing %q: %v", src.RemoteAddr().String(), dp.Addr, dstDialErr)
|
|
src.Close()
|
|
}
|
|
}
|