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Support ALPN for TCP + TLS routers

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This commit is contained in:
Dmitry Sharshakov 2022-07-07 17:58:09 +03:00 • committed by GitHub
parent aff334ffb4
commit 4dc379c601
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GPG key ID: 4AEE18F83AFDEB23
4 changed files with 228 additions and 34 deletions
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77
pkg/server/router/tcp/router.go
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@ -83,10 +83,10 @@ func (r *Router) ServeTCP(conn tcp.WriteCloser) {
// Handling Non-TLS TCP connection early if there is neither HTTP(S) nor TLS
// routers on the entryPoint, and if there is at least one non-TLS TCP router.
// In the case of a non-TLS TCP client (that does not "send" first), we would
// block forever on clientHelloServerName, which is why we want to detect and
// block forever on clientHelloInfo, which is why we want to detect and
// handle that case first and foremost.
if r.muxerTCP.HasRoutes() && !r.muxerTCPTLS.HasRoutes() && !r.muxerHTTPS.HasRoutes() {
connData, err := tcpmuxer.NewConnData("", conn)
connData, err := tcpmuxer.NewConnData("", conn, nil)
if err != nil {
log.WithoutContext().Errorf("Error while reading TCP connection data: %v", err)
conn.Close()
@ -108,7 +108,7 @@ func (r *Router) ServeTCP(conn tcp.WriteCloser) {
// FIXME -- Check if ProxyProtocol changes the first bytes of the request
br := bufio.NewReader(conn)
serverName, tls, peeked, err := clientHelloServerName(br)
hello, err := clientHelloInfo(br)
if err != nil {
conn.Close()
return
@ -125,20 +125,20 @@ func (r *Router) ServeTCP(conn tcp.WriteCloser) {
log.WithoutContext().Errorf("Error while setting write deadline: %v", err)
}
connData, err := tcpmuxer.NewConnData(serverName, conn)
connData, err := tcpmuxer.NewConnData(hello.serverName, conn, hello.protos)
if err != nil {
log.WithoutContext().Errorf("Error while reading TCP connection data: %v", err)
conn.Close()
return
}
if !tls {
if !hello.isTLS {
handler, _ := r.muxerTCP.Match(connData)
switch {
case handler != nil:
handler.ServeTCP(r.GetConn(conn, peeked))
handler.ServeTCP(r.GetConn(conn, hello.peeked))
case r.httpForwarder != nil:
r.httpForwarder.ServeTCP(r.GetConn(conn, peeked))
r.httpForwarder.ServeTCP(r.GetConn(conn, hello.peeked))
default:
conn.Close()
}
@ -155,14 +155,14 @@ func (r *Router) ServeTCP(conn tcp.WriteCloser) {
// In order not to depart from the behavior in 2.6, we only allow an HTTPS router
// to take precedence over a TCP-TLS router if it is _not_ an HostSNI(*) router (so
// basically any router that has a specific HostSNI based rule).
handlerHTTPS.ServeTCP(r.GetConn(conn, peeked))
handlerHTTPS.ServeTCP(r.GetConn(conn, hello.peeked))
return
}
// Contains also TCP TLS passthrough routes.
handlerTCPTLS, catchAllTCPTLS := r.muxerTCPTLS.Match(connData)
if handlerTCPTLS != nil && !catchAllTCPTLS {
handlerTCPTLS.ServeTCP(r.GetConn(conn, peeked))
handlerTCPTLS.ServeTCP(r.GetConn(conn, hello.peeked))
return
}
@ -170,19 +170,19 @@ func (r *Router) ServeTCP(conn tcp.WriteCloser) {
// We end up here for e.g. an HTTPS router that only has a PathPrefix rule,
// which under the scenes is counted as an HostSNI(*) rule.
if handlerHTTPS != nil {
handlerHTTPS.ServeTCP(r.GetConn(conn, peeked))
handlerHTTPS.ServeTCP(r.GetConn(conn, hello.peeked))
return
}
// Fallback on TCP TLS catchAll.
if handlerTCPTLS != nil {
handlerTCPTLS.ServeTCP(r.GetConn(conn, peeked))
handlerTCPTLS.ServeTCP(r.GetConn(conn, hello.peeked))
return
}
// needed to handle 404s for HTTPS, as well as all non-Host (e.g. PathPrefix) matches.
if r.httpsForwarder != nil {
r.httpsForwarder.ServeTCP(r.GetConn(conn, peeked))
r.httpsForwarder.ServeTCP(r.GetConn(conn, hello.peeked))
return
}
@ -300,18 +300,24 @@ func (c *Conn) Read(p []byte) (n int, err error) {
return c.WriteCloser.Read(p)
}
// clientHelloServerName returns the SNI server name inside the TLS ClientHello,
type clientHello struct {
serverName string // SNI server name
protos []string // ALPN protocols list
isTLS bool // whether we are a TLS handshake
peeked string // the bytes peeked from the hello while getting the info
}
// clientHelloInfo returns various data from the clientHello handshake,
// without consuming any bytes from br.
// On any error, the empty string is returned.
func clientHelloServerName(br *bufio.Reader) (string, bool, string, error) {
// It returns an error if it can't peek the first byte from the connection.
func clientHelloInfo(br *bufio.Reader) (*clientHello, error) {
hdr, err := br.Peek(1)
if err != nil {
var opErr *net.OpError
if !errors.Is(err, io.EOF) && (!errors.As(err, &opErr) || opErr.Timeout()) {
log.WithoutContext().Errorf("Error while Peeking first byte: %s", err)
}
return "", false, "", err
return nil, err
}
// No valid TLS record has a type of 0x80, however SSLv2 handshakes
@ -323,16 +329,23 @@ func clientHelloServerName(br *bufio.Reader) (string, bool, string, error) {
if hdr[0] != recordTypeHandshake {
if hdr[0] == recordTypeSSLv2 {
// we consider SSLv2 as TLS and it will be refused by real TLS handshake.
return "", true, getPeeked(br), nil
return &clientHello{
isTLS: true,
peeked: getPeeked(br),
}, nil
}
return "", false, getPeeked(br), nil // Not TLS.
return &clientHello{
peeked: getPeeked(br),
}, nil // Not TLS.
}
const recordHeaderLen = 5
hdr, err = br.Peek(recordHeaderLen)
if err != nil {
log.Errorf("Error while Peeking hello: %s", err)
return "", false, getPeeked(br), nil
return &clientHello{
peeked: getPeeked(br),
}, nil
}
recLen := int(hdr[3])<<8 | int(hdr[4]) // ignoring version in hdr[1:3]
@ -344,19 +357,29 @@ func clientHelloServerName(br *bufio.Reader) (string, bool, string, error) {
helloBytes, err := br.Peek(recordHeaderLen + recLen)
if err != nil {
log.Errorf("Error while Hello: %s", err)
return "", true, getPeeked(br), nil
return &clientHello{
isTLS: true,
peeked: getPeeked(br),
}, nil
}
sni := ""
server := tls.Server(sniSniffConn{r: bytes.NewReader(helloBytes)}, &tls.Config{
var protos []string
server := tls.Server(helloSniffConn{r: bytes.NewReader(helloBytes)}, &tls.Config{
GetConfigForClient: func(hello *tls.ClientHelloInfo) (*tls.Config, error) {
sni = hello.ServerName
protos = hello.SupportedProtos
return nil, nil
},
})
_ = server.Handshake()
return sni, true, getPeeked(br), nil
return &clientHello{
serverName: sni,
isTLS: true,
peeked: getPeeked(br),
protos: protos,
}, nil
}
func getPeeked(br *bufio.Reader) string {
@ -368,15 +391,15 @@ func getPeeked(br *bufio.Reader) string {
return string(peeked)
}
// sniSniffConn is a net.Conn that reads from r, fails on Writes,
// helloSniffConn is a net.Conn that reads from r, fails on Writes,
// and crashes otherwise.
type sniSniffConn struct {
type helloSniffConn struct {
r io.Reader
net.Conn // nil; crash on any unexpected use
}
// Read reads from the underlying reader.
func (c sniSniffConn) Read(p []byte) (int, error) { return c.r.Read(p) }
func (c helloSniffConn) Read(p []byte) (int, error) { return c.r.Read(p) }
// Write crashes all the time.
func (sniSniffConn) Write(p []byte) (int, error) { return 0, io.EOF }
func (helloSniffConn) Write(p []byte) (int, error) { return 0, io.EOF }