package mplexy import ( "bufio" "bytes" "context" "crypto/tls" "encoding/hex" "fmt" "net" "net/http" "strconv" "strings" "time" telebit "git.coolaj86.com/coolaj86/go-telebitd" "git.coolaj86.com/coolaj86/go-telebitd/packer" "git.coolaj86.com/coolaj86/go-telebitd/relay/api" "git.coolaj86.com/coolaj86/go-telebitd/sni" "git.coolaj86.com/coolaj86/go-telebitd/tunnel" ) type contextKey string //CtxConnectionTrack const ( ctxServerStatus contextKey = "serverstatus" ctxConfig contextKey = "tlsConfig" ctxListenerRegistration contextKey = "listenerRegistration" ctxConnectionTrack contextKey = "connectionTrack" ctxWssHostName contextKey = "wsshostname" ctxAdminHostName contextKey = "adminHostName" ctxCancelCheck contextKey = "cancelcheck" ctxLoadbalanceDefaultMethod contextKey = "lbdefaultmethod" //ctxConnectionTable contextKey = "connectionTable" ) // TODO isn't this restriction in the TLS lib? // or are we just pre-checking for remote hosts? type tlsScheme int const ( encryptNone tlsScheme = iota encryptSSLV2 encryptSSLV3 encryptTLS10 encryptTLS11 encryptTLS12 encryptTLS13 ) // multiListenAndServe -- used to lisen for any https traffic on 443 (8443) // - setup generic TCP listener, unencrypted TCP, with a Deadtime out // - leaverage the wedgeConn to peek into the buffer. // - if TLS, consume connection with TLS certbundle, pass to request identifier // - else, just pass to the request identififer func (mx *MPlexy) multiListenAndServe(ctx context.Context, listenerRegistration *ListenerRegistration) { Loginfo.Println(":" + string(listenerRegistration.port)) cancelCheck := ctx.Value(ctxCancelCheck).(int) listenAddr, err := net.ResolveTCPAddr("tcp", ":"+strconv.Itoa(listenerRegistration.port)) if nil != err { Loginfo.Println(err) return } ln, err := net.ListenTCP("tcp", listenAddr) if err != nil { Loginfo.Println("unable to bind", err) listenerRegistration.status = listenerFault listenerRegistration.err = err listenerRegistration.commCh <- listenerRegistration return } listenerRegistration.status = listenerAdded listenerRegistration.commCh <- listenerRegistration for { select { case <-ctx.Done(): Loginfo.Println("Cancel signal hit") return default: ln.SetDeadline(time.Now().Add(time.Duration(cancelCheck) * time.Second)) conn, err := ln.Accept() if nil != err { if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() { continue } Loginfo.Println(err) return } fmt.Println("New connection from %v on %v", conn.LocalAddr(), conn.RemoteAddr()) // TODO maybe put these into something like mx.newConnCh and have an mx.Accept()? wedgeConn := tunnel.NewWedgeConn(conn) go mx.accept(ctx, wedgeConn) } } } //accept - // - accept a wedgeConnection along with all the other required attritvues // - peek into the buffer, determine TLS or unencrypted // - if TSL, then terminate with a TLS endpoint, pass to acceptEcryptedStream // - if clearText, pass to acceptPlainStream func (mx *MPlexy) accept(ctx context.Context, wConn *tunnel.WedgeConn) { peekCnt := 10 encryptMode := encryptNone Loginfo.Println("new conn", wConn, wConn.LocalAddr().String(), wConn.RemoteAddr().String()) peek, err := wConn.Peek(peekCnt) if err != nil { Loginfo.Println("error while peeking") wConn.Close() return } //take a look for a TLS header. if bytes.Contains(peek[0:0], []byte{0x80}) && bytes.Contains(peek[2:4], []byte{0x01, 0x03}) { encryptMode = encryptSSLV2 } else if bytes.Contains(peek[0:3], []byte{0x16, 0x03, 0x00}) { encryptMode = encryptSSLV3 } else if bytes.Contains(peek[0:3], []byte{0x16, 0x03, 0x01}) { encryptMode = encryptTLS10 Loginfo.Println("TLS10") } else if bytes.Contains(peek[0:3], []byte{0x16, 0x03, 0x02}) { encryptMode = encryptTLS11 } else if bytes.Contains(peek[0:3], []byte{0x16, 0x03, 0x03}) { encryptMode = encryptTLS12 } else if bytes.Contains(peek[0:3], []byte{0x16, 0x03, 0x04}) { encryptMode = encryptTLS13 } if encryptMode == encryptSSLV2 { Loginfo.Println("<= SSLv2 is not accepted") wConn.Close() return } if encryptMode == encryptNone { Loginfo.Println("Handle Unencrypted") mx.acceptPlainStream(ctx, wConn, false) return } Loginfo.Println("Handle Encryption") mx.acceptEncryptedStream(ctx, wConn) } func (mx *MPlexy) acceptEncryptedStream(ctx context.Context, wConn *tunnel.WedgeConn) { // Peek at SNI (ServerName) from TLS Hello header peek, err := wConn.PeekAll() if err != nil { Loginfo.Println("Bad socket: read error from", wConn.RemoteAddr(), err) Loginfo.Println(hex.Dump(peek[0:])) wConn.Close() return } sniHostName, err := sni.GetHostname(peek) if err != nil { Loginfo.Println("Bad socket: no SNI from", wConn.RemoteAddr(), err) Loginfo.Println(err) wConn.Close() return } Loginfo.Println("SNI:", sniHostName) if sniHostName == mx.wssHostName || sniHostName == mx.adminHostName { // The TLS should be terminated and handled internally tlsConfig := ctx.Value(ctxConfig).(*tls.Config) conn := tls.Client(wConn, tlsConfig) tlsWedgeConn := tunnel.NewWedgeConn(conn) mx.acceptPlainStream(ctx, tlsWedgeConn, true) return } //oneConn := &oneConnListener{wConn} // TLS remains intact and shall be routed downstream, wholesale Loginfo.Println("processing non terminating traffic", mx.wssHostName, sniHostName) go mx.routeToTarget(ctx, wConn, sniHostName, "https") } //acceptPlainStream -- // - we have an unencrypted stream connection with the ability to peek // - attempt to identify HTTP // - handle http // - attempt to identify as WSS session // - attempt to identify as ADMIN/API session // - else handle as raw http // - handle other? func (mx *MPlexy) acceptPlainStream(ctx context.Context, wConn *tunnel.WedgeConn, encrypted bool) { Loginfo.Println("Plain Conn", wConn.LocalAddr().String(), wConn.RemoteAddr().String()) // TODO couldn't reading everything be dangerous? Or is it limited to a single packet? peek, err := wConn.PeekAll() if err != nil { Loginfo.Println("error while peeking", err) Loginfo.Println(hex.Dump(peek[0:])) wConn.Close() return } // TODO handle by TCP port as well // (which needs a short read timeout since servers expect clients to say hello) // HTTP Identifcation // CRLF if !bytes.Contains(peek[:], []byte{0x0d, 0x0a}) { wConn.Close() return } //string protocol if !bytes.ContainsAny(peek[:], "HTTP/") { wConn.Close() return } Loginfo.Println("identified HTTP") r, err := http.ReadRequest(bufio.NewReader(bytes.NewReader(peek))) if err != nil { Loginfo.Println("identified as HTTP, failed request parsing", err) wConn.Close() return } if strings.Contains(r.Host, telebit.InvalidAdminDomain) { Loginfo.Println("admin") // TODO mx.Admin.CheckRemoteIP(conn) here // handle admin path mx.AcceptAdminClient(wConn) return } // TODO add newtypes // TODO check if this is a websocket _, err = mx.AuthorizeTarget(r) if err == nil { Loginfo.Println("Valid WSS dected...sending to handler") mx.AcceptTargetServer(wConn) return } // TODO sniHostName is the key to the route, which could also be a port or hostname //traffic not terminating on the rvpn do not decrypt Loginfo.Println("processing non terminating traffic", mx.wssHostName, r.Host) Loginfo.Println(hex.Dump(peek)) if !encrypted { // TODO request and cache http resources as a feature?? go mx.routeToTarget(ctx, wConn, r.Host, "http") return } // This is not presently possible Loginfo.Println("impossible condition: local decryption of routable client", mx.wssHostName, r.Host) go mx.routeToTarget(ctx, wConn, r.Host, "https") } //routeToTarget - // - get a wConn and start processing requests func (mx *MPlexy) routeToTarget(ctx context.Context, extConn *tunnel.WedgeConn, hostname, service string) { // TODO is this the right place to do this? defer extConn.Close() //connectionTracking := ctx.Value(ctxConnectionTrack).(*Tracking) serverStatus := ctx.Value(ctxServerStatus).(*api.Status) defer func() { serverStatus.ExtConnectionUnregister(extConn) extConn.Close() }() //find the connection by domain name conn, ok := serverStatus.ConnectionTable.ConnByDomain(hostname) if !ok { //matching connection can not be found based on ConnByDomain Loginfo.Println("unable to match ", hostname, " to an existing connection") //http.Error(, "Domain not supported", http.StatusBadRequest) return } track := api.NewTrack(extConn, hostname) serverStatus.ExtConnectionRegister(track) remoteStr := extConn.RemoteAddr().String() Loginfo.Println("Domain Accepted", hostname, remoteStr) var header *packer.Header if rAddr, rPort, err := net.SplitHostPort(remoteStr); err != nil { Loginfo.Println("unable to decode hostport", remoteStr, err) } else if port, err := strconv.Atoi(rPort); err != nil { Loginfo.Printf("unable to parse port string %q: %v\n", rPort, err) } else if header, err = packer.NewHeader(rAddr, port, service); err != nil { Loginfo.Println("unable to create packer header", err) } if header == nil { return } for { buffer, err := extConn.PeekAll() if err != nil { Loginfo.Println("unable to peekAll", err) return } Loginfo.Println("Before Packer", hex.Dump(buffer)) p := packer.NewPacker(header) p.Data.AppendBytes(buffer) buf := p.PackV1() //Loginfo.Println(hex.Dump(buf.Bytes())) //Bundle up the send request and dispatch sendTrack := api.NewSendTrack(buf.Bytes(), hostname) serverStatus.SendExtRequest(conn, sendTrack) cnt := len(buffer) if _, err = extConn.Discard(cnt); err != nil { Loginfo.Println("unable to discard", cnt, err) return } } }