Merge branch 'client'

go-rvpn-client/main.go

@@ -0,0 +1,208 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	jwt "github.com/dgrijalva/jwt-go"
+	flag "github.com/spf13/pflag"
+	"github.com/spf13/viper"
+
+	"git.daplie.com/Daplie/go-rvpn-server/rvpn/client"
+)
+
+var httpRegexp = regexp.MustCompile(`(?i)^http`)
+
+func init() {
+	flag.StringSlice("locals", []string{}, "comma separated list of <proto>:<port> or "+
+		"<proto>:<hostname>:<port> to which matching incoming connections should forward. "+
+		"Ex: smtps:8465,https:example.com:8443")
+	flag.StringSlice("domains", []string{}, "comma separated list of domain names to set to the tunnel")
+	viper.BindPFlag("locals", flag.Lookup("locals"))
+	viper.BindPFlag("domains", flag.Lookup("domains"))
+
+	flag.BoolP("insecure", "k", false, "Allow TLS connections to stunneld without valid certs")
+	flag.String("stunneld", "", "the domain (or ip address) at which the RVPN server is running")
+	flag.String("secret", "", "the same secret used by stunneld (used for JWT authentication)")
+	flag.String("token", "", "a pre-generated token to give the server (instead of generating one with --secret)")
+	viper.BindPFlag("raw.insecure", flag.Lookup("insecure"))
+	viper.BindPFlag("raw.stunneld", flag.Lookup("stunneld"))
+	viper.BindPFlag("raw.secret", flag.Lookup("secret"))
+	viper.BindPFlag("raw.token", flag.Lookup("token"))
+}
+
+type proxy struct {
+	protocol string
+	hostname string
+	port     int
+}
+
+func addLocals(proxies []proxy, location string) []proxy {
+	parts := strings.Split(location, ":")
+	if len(parts) > 3 {
+		panic(fmt.Sprintf("provided invalid location %q", location))
+	}
+
+	// If all that was provided as a "local" is the domain name we assume that domain
+	// has HTTP and HTTPS handlers on the default ports.
+	if len(parts) == 1 {
+		proxies = append(proxies, proxy{"http", parts[0], 80})
+		proxies = append(proxies, proxy{"https", parts[0], 443})
+		return proxies
+	}
+
+	// Make everything lower case and trim any slashes in something like https://john.example.com
+	parts[0] = strings.ToLower(parts[0])
+	parts[1] = strings.ToLower(strings.Trim(parts[1], "/"))
+
+	if len(parts) == 2 {
+		if strings.Contains(parts[1], ".") {
+			if parts[0] == "http" {
+				parts = append(parts, "80")
+			} else if parts[0] == "https" {
+				parts = append(parts, "443")
+			} else {
+				panic(fmt.Sprintf("port must be specified for %q", location))
+			}
+		} else {
+			// https:3443 -> https:*:3443
+			parts = []string{parts[0], "*", parts[1]}
+		}
+	}
+
+	if port, err := strconv.Atoi(parts[2]); err != nil {
+		panic(fmt.Sprintf("port must be a valid number, not %q: %v", parts[2], err))
+	} else if port <= 0 || port > 65535 {
+		panic(fmt.Sprintf("%d is an invalid port for local services", port))
+	} else {
+		proxies = append(proxies, proxy{parts[0], parts[1], port})
+	}
+	return proxies
+}
+
+func addDomains(proxies []proxy, location string) []proxy {
+	parts := strings.Split(location, ":")
+	if len(parts) > 3 {
+		panic(fmt.Sprintf("provided invalid location %q", location))
+	} else if len(parts) == 2 {
+		panic("invalid argument for --domains, use format <domainname> or <scheme>:<domainname>:<local-port>")
+	}
+
+	// If the scheme and port weren't provided use the zero values
+	if len(parts) == 1 {
+		return append(proxies, proxy{"", parts[0], 0})
+	}
+
+	if port, err := strconv.Atoi(parts[2]); err != nil {
+		panic(fmt.Sprintf("port must be a valid number, not %q: %v", parts[2], err))
+	} else if port <= 0 || port > 65535 {
+		panic(fmt.Sprintf("%d is an invalid port for local services", port))
+	} else {
+		proxies = append(proxies, proxy{parts[0], parts[1], port})
+	}
+	return proxies
+}
+
+func extractServicePorts(proxies []proxy) map[string]map[string]int {
+	result := make(map[string]map[string]int, 2)
+
+	for _, p := range proxies {
+		if p.protocol != "" && p.port != 0 {
+			hostPorts := result[p.protocol]
+			if hostPorts == nil {
+				result[p.protocol] = make(map[string]int)
+				hostPorts = result[p.protocol]
+			}
+
+			// Only HTTP and HTTPS allow us to determine the hostname from the request, so only
+			// those protocols support different ports for the same service.
+			if !httpRegexp.MatchString(p.protocol) || p.hostname == "" {
+				p.hostname = "*"
+			}
+			if port, ok := hostPorts[p.hostname]; ok && port != p.port {
+				panic(fmt.Sprintf("duplicate ports for %s://%s", p.protocol, p.hostname))
+			}
+			hostPorts[p.hostname] = p.port
+		}
+	}
+
+	// Make sure we have defaults for HTTPS and HTTP.
+	if result["https"] == nil {
+		result["https"] = make(map[string]int, 1)
+	}
+	if result["https"]["*"] == 0 {
+		result["https"]["*"] = 8443
+	}
+
+	if result["http"] == nil {
+		result["http"] = make(map[string]int, 1)
+	}
+	if result["http"]["*"] == 0 {
+		result["http"]["*"] = result["https"]["*"]
+	}
+
+	return result
+}
+
+func main() {
+	flag.Parse()
+
+	proxies := make([]proxy, 0)
+	for _, option := range viper.GetStringSlice("locals") {
+		for _, location := range strings.Split(option, ",") {
+			proxies = addLocals(proxies, location)
+		}
+	}
+	for _, option := range viper.GetStringSlice("domains") {
+		for _, location := range strings.Split(option, ",") {
+			proxies = addDomains(proxies, location)
+		}
+	}
+
+	servicePorts := extractServicePorts(proxies)
+	domainMap := make(map[string]bool)
+	for _, p := range proxies {
+		if p.hostname != "" && p.hostname != "*" {
+			domainMap[p.hostname] = true
+		}
+	}
+
+	if viper.GetString("raw.stunneld") == "" {
+		panic("must provide remote RVPN server to connect to")
+	}
+
+	var token string
+	if viper.GetString("raw.token") != "" {
+		token = viper.GetString("raw.token")
+	} else if viper.GetString("raw.secret") != "" {
+		domains := make([]string, 0, len(domainMap))
+		for name := range domainMap {
+			domains = append(domains, name)
+		}
+		tokenData := jwt.MapClaims{"domains": domains}
+
+		secret := []byte(viper.GetString("raw.secret"))
+		jwtToken := jwt.NewWithClaims(jwt.SigningMethodHS256, tokenData)
+		if tokenStr, err := jwtToken.SignedString(secret); err != nil {
+			panic(err)
+		} else {
+			token = tokenStr
+		}
+	} else {
+		panic("must provide either token or secret")
+	}
+
+	ctx, quit := context.WithCancel(context.Background())
+	defer quit()
+
+	config := client.Config{
+		Insecure: viper.GetBool("raw.insecure"),
+		Server:   viper.GetString("raw.stunneld"),
+		Services: servicePorts,
+		Token:    token,
+	}
+	panic(client.Run(ctx, &config))
+}

rvpn/client/client.go

@@ -0,0 +1,71 @@
+package client
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+// The Config struct holds all of the information needed to establish and handle a connection
+// with the RVPN server.
+type Config struct {
+	Server   string
+	Token    string
+	Insecure bool
+	Services map[string]map[string]int
+}
+
+// Run establishes a connection with the RVPN server specified in the config. If the first attempt
+// to connect fails it is assumed that something is wrong with the authentication and it will
+// return an error. Otherwise it will continuously attempt to reconnect whenever the connection
+// is broken.
+func Run(ctx context.Context, config *Config) error {
+	serverURL, err := url.Parse(config.Server)
+	if err != nil {
+		return fmt.Errorf("Invalid server URL: %v", err)
+	}
+	if serverURL.Scheme == "" {
+		serverURL.Scheme = "wss"
+	}
+	serverURL.Path = ""
+
+	query := make(url.Values)
+	query.Set("access_token", config.Token)
+	serverURL.RawQuery = query.Encode()
+
+	dialer := websocket.Dialer{}
+	if config.Insecure {
+		dialer.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+	}
+
+	for name, portList := range config.Services {
+		if _, ok := portList["*"]; !ok {
+			return fmt.Errorf(`service %s missing port for "*"`, name)
+		}
+	}
+	handler := NewWsHandler(config.Services)
+
+	authenticated := false
+	for {
+		if conn, _, err := dialer.Dial(serverURL.String(), nil); err == nil {
+			loginfo.Println("connected to remote server")
+			authenticated = true
+			handler.HandleConn(ctx, conn)
+		} else if !authenticated {
+			return fmt.Errorf("First connection to server failed - check auth: %v", err)
+		}
+		loginfo.Println("disconnected from remote server")
+
+		// Sleep for a few seconds before trying again, but only if the context is still active
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-time.After(5 * time.Second):
+		}
+		loginfo.Println("attempting reconnect to remote server")
+	}
+}

rvpn/client/setup.go

@@ -0,0 +1,15 @@
+package client
+
+import (
+	"log"
+	"os"
+)
+
+const (
+	logFlags = log.Ldate | log.Lmicroseconds | log.Lshortfile
+)
+
+var (
+	loginfo  = log.New(os.Stdout, "INFO: client: ", logFlags)
+	logdebug = log.New(os.Stdout, "DEBUG: client:", logFlags)
+)

rvpn/client/ws_handler.go

@@ -0,0 +1,233 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/gorilla/websocket"
+
+	"git.daplie.com/Daplie/go-rvpn-server/rvpn/packer"
+	"git.daplie.com/Daplie/go-rvpn-server/rvpn/sni"
+)
+
+var hostRegexp = regexp.MustCompile(`(?im)(?:^|[\r\n])Host: *([^\r\n]+)[\r\n]`)
+
+// WsHandler handles all of reading and writing for the websocket connection to the RVPN server
+// and the TCP connections to the local servers.
+type WsHandler struct {
+	lock       sync.Mutex
+	localConns map[string]net.Conn
+
+	servicePorts map[string]map[string]int
+
+	ctx      context.Context
+	dataChan chan *packer.Packer
+}
+
+// NewWsHandler creates a new handler ready to be given a websocket connection. The services
+// argument specifies what port each service type should be directed to on the local interface.
+func NewWsHandler(services map[string]map[string]int) *WsHandler {
+	h := new(WsHandler)
+	h.servicePorts = services
+	h.localConns = make(map[string]net.Conn)
+	return h
+}
+
+// HandleConn handles all of the traffic on the provided websocket connection. The function
+// will not return until the connection ends.
+//
+// The WsHandler is designed to handle exactly one connection at a time. If HandleConn is called
+// again while the instance is still handling another connection (or if the previous connection
+// failed to fully cleanup) calling HandleConn again will panic.
+func (h *WsHandler) HandleConn(ctx context.Context, conn *websocket.Conn) {
+	if h.dataChan != nil {
+		panic("WsHandler.HandleConn called while handling a previous connection")
+	}
+	if len(h.localConns) > 0 {
+		panic(fmt.Sprintf("WsHandler has lingering local connections: %v", h.localConns))
+	}
+	h.dataChan = make(chan *packer.Packer)
+
+	// The sub context allows us to clean up all of the goroutines associated with this websocket
+	// if it closes at any point for any reason.
+	subCtx, socketQuit := context.WithCancel(ctx)
+	defer socketQuit()
+	h.ctx = subCtx
+
+	// Start the routine that will write all of the data from the local connection to the
+	// remote websocket connection.
+	go h.writeRemote(conn)
+
+	for {
+		_, message, err := conn.ReadMessage()
+		if err != nil {
+			loginfo.Println("failed to read message from websocket", err)
+			return
+		}
+
+		p, err := packer.ReadMessage(message)
+		if err != nil {
+			loginfo.Println("failed to parse message from websocket", err)
+			return
+		}
+
+		h.writeLocal(p)
+	}
+}
+
+func (h *WsHandler) writeRemote(conn *websocket.Conn) {
+	defer h.closeConnections()
+	defer func() { h.dataChan = nil }()
+
+	for {
+		select {
+		case <-h.ctx.Done():
+			// We can't tell if this happened because the websocket is already closed/errored or
+			// if it happened because the main context closed (in which case it would be preferable
+			// to properly close the connection). As such we try to close the connection and ignore
+			// all errors if it doesn't work.
+			message := websocket.FormatCloseMessage(websocket.CloseGoingAway, "closing connection")
+			deadline := time.Now().Add(10 * time.Second)
+			conn.WriteControl(websocket.CloseMessage, message, deadline)
+			conn.Close()
+			return
+
+		case p := <-h.dataChan:
+			packed := p.PackV1()
+			conn.WriteMessage(websocket.BinaryMessage, packed.Bytes())
+		}
+	}
+}
+
+func (h *WsHandler) sendPackedMessage(header *packer.Header, data []byte, service string) {
+	p := packer.NewPacker(header)
+	if len(data) > 0 {
+		p.Data.AppendBytes(data)
+	}
+	if service != "" {
+		p.SetService(service)
+	}
+
+	// Avoid blocking on the data channel if the websocket closes or is already closed
+	select {
+	case h.dataChan <- p:
+	case <-h.ctx.Done():
+	}
+}
+
+func (h *WsHandler) getLocalConn(p *packer.Packer) net.Conn {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	key := fmt.Sprintf("%s:%d", p.Address(), p.Port())
+	// Simplest case: it's already open, just return it.
+	if conn := h.localConns[key]; conn != nil {
+		return conn
+	}
+
+	service := strings.ToLower(p.Service())
+	portList := h.servicePorts[service]
+	if portList == nil {
+		loginfo.Println("cannot open connection for invalid service", service)
+		return nil
+	}
+
+	var hostname string
+	if service == "http" {
+		if match := hostRegexp.FindSubmatch(p.Data.Data()); match != nil {
+			hostname = strings.Split(string(match[1]), ":")[0]
+		}
+	} else if service == "https" {
+		hostname, _ = sni.GetHostname(p.Data.Data())
+	} else {
+		hostname = "*"
+	}
+	if hostname == "" {
+		loginfo.Println("missing servername for", service, key)
+		return nil
+	}
+	hostname = strings.ToLower(hostname)
+
+	port := portList[hostname]
+	if port == 0 {
+		port = portList["*"]
+	}
+	if port == 0 {
+		loginfo.Println("unable to determine local port for", service, hostname)
+		return nil
+	}
+
+	conn, err := net.Dial("tcp", fmt.Sprintf("127.0.0.1:%d", port))
+	if err != nil {
+		loginfo.Println("unable to open local connection on port", port, err)
+		return nil
+	}
+
+	h.localConns[key] = conn
+	loginfo.Printf("new client %q for %s:%d (%d clients)\n", key, hostname, port, len(h.localConns))
+	go h.readLocal(key, &p.Header)
+	return conn
+}
+
+func (h *WsHandler) writeLocal(p *packer.Packer) {
+	conn := h.getLocalConn(p)
+	if conn == nil {
+		h.sendPackedMessage(&p.Header, nil, "error")
+		return
+	}
+
+	if p.Service() == "error" || p.Service() == "end" {
+		conn.Close()
+		return
+	}
+
+	if _, err := conn.Write(p.Data.Data()); err != nil {
+		h.sendPackedMessage(&p.Header, nil, "error")
+		loginfo.Println("failed to write to local connection", err)
+	}
+}
+
+func (h *WsHandler) readLocal(key string, header *packer.Header) {
+	h.lock.Lock()
+	conn := h.localConns[key]
+	h.lock.Unlock()
+
+	defer conn.Close()
+	defer func() {
+		h.lock.Lock()
+		delete(h.localConns, key)
+		loginfo.Printf("closing client %q: (%d clients)\n", key, len(h.localConns))
+		h.lock.Unlock()
+	}()
+
+	buf := make([]byte, 4096)
+	for {
+		size, err := conn.Read(buf)
+		if err != nil {
+			if err == io.EOF || strings.Contains(err.Error(), "use of closed network connection") {
+				h.sendPackedMessage(header, nil, "end")
+			} else {
+				loginfo.Println("failed to read from local connection for", key, err)
+				h.sendPackedMessage(header, nil, "error")
+			}
+			return
+		}
+
+		h.sendPackedMessage(header, buf[:size], "")
+	}
+}
+
+func (h *WsHandler) closeConnections() {
+	h.lock.Lock()
+	defer h.lock.Unlock()
+
+	for _, conn := range h.localConns {
+		conn.Close()
+	}
+}

rvpn/packer/packer.go

@@ -16,16 +16,19 @@ const (
 
 //Packer -- contains both header and data
 type Packer struct {
-	Header *packerHeader
-	Data   *packerData
+	Header
+	Data packerData
 }
 
-//NewPacker -- Structre
-func NewPacker() (p *Packer) {
-	p = new(Packer)
-	p.Header = newPackerHeader()
-	p.Data = newPackerData()
-	return
+// NewPacker creates a new Packer struct using the information from the provided header as
+// its own header. (Because the header is stored directly and not as a pointer/reference
+// it should be safe to override items like the service without affecting the template header.)
+func NewPacker(header *Header) *Packer {
+	p := new(Packer)
+	if header != nil {
+		p.Header = *header
+	}
+	return p
 }
 
 func splitHeader(header []byte, names []string) (map[string]string, error) {
@@ -48,7 +51,7 @@ func ReadMessage(b []byte) (*Packer, error) {
 	// Detect protocol in use
 	if b[0] == packerV1 {
 		// Separate the header and body using the header length in the second byte.
-		p := NewPacker()
+		p := NewPacker(nil)
 		header := b[2 : b[1]+2]
 		data := b[b[1]+2:]
 
@@ -69,8 +72,8 @@ func ReadMessage(b []byte) (*Packer, error) {
 		p.Header.address = net.ParseIP(parts["address"])
 		if p.Header.address == nil {
 			return nil, fmt.Errorf("Invalid network address %q", parts["address"])
-		} else if p.Header.Family() == FamilyIPv4 && p.Header.address.To4() == nil {
-			return nil, fmt.Errorf("Address %q is not in address family %s", parts["address"], p.Header.FamilyText())
+		} else if p.Header.family == FamilyIPv4 && p.Header.address.To4() == nil {
+			return nil, fmt.Errorf("Address %q is not in address family %s", parts["address"], p.Header.Family())
 		}
 
 		//handle port
@@ -79,7 +82,7 @@ func ReadMessage(b []byte) (*Packer, error) {
 		} else if port <= 0 || port > 65535 {
 			return nil, fmt.Errorf("Port %d out of range", port)
 		} else {
-			p.Header.Port = port
+			p.Header.port = port
 		}
 
 		//handle data length
@@ -90,7 +93,7 @@ func ReadMessage(b []byte) (*Packer, error) {
 		}
 
 		//handle Service
-		p.Header.Service = parts["service"]
+		p.Header.service = parts["service"]
 
 		//handle payload
 		p.Data.AppendBytes(data)
@@ -103,11 +106,11 @@ func ReadMessage(b []byte) (*Packer, error) {
 //PackV1 -- Outputs version 1 of packer
 func (p *Packer) PackV1() bytes.Buffer {
 	header := strings.Join([]string{
-		p.Header.FamilyText(),
-		p.Header.AddressString(),
-		strconv.Itoa(p.Header.Port),
+		p.Header.Family(),
+		p.Header.Address(),
+		strconv.Itoa(p.Header.Port()),
 		strconv.Itoa(p.Data.DataLen()),
-		p.Header.Service,
+		p.Header.Service(),
 	}, ",")
 
 	var buf bytes.Buffer

rvpn/packer/packer_data.go

@@ -9,10 +9,6 @@ type packerData struct {
 	buffer bytes.Buffer
 }
 
-func newPackerData() *packerData {
-	return new(packerData)
-}
-
 func (p *packerData) AppendString(dataString string) (int, error) {
 	return p.buffer.WriteString(dataString)
 }

rvpn/packer/packer_header.go

@@ -7,12 +7,15 @@ import (
 
 type addressFamily int
 
-// packerHeader structure to hold our header information.
-type packerHeader struct {
+// The Header struct holds most of the information contained in the header for packets
+// between the client and the server (the length of the data is not included here). It
+// is used to uniquely identify remote connections on the servers end and to communicate
+// which service the remote client is trying to connect to.
+type Header struct {
 	family  addressFamily
 	address net.IP
-	Port    int
-	Service string
+	port    int
+	service string
 }
 
 //Family -- ENUM for Address Family
@@ -26,16 +29,19 @@ var addressFamilyText = [...]string{
 	"IPv6",
 }
 
-func newPackerHeader() (p *packerHeader) {
-	p = new(packerHeader)
-	p.SetAddress("127.0.0.1")
-	p.Port = 65535
-	p.Service = "na"
-	return
+// NewHeader create a new Header object.
+func NewHeader(address string, port int, service string) (*Header, error) {
+	h := new(Header)
+	if err := h.setAddress(address); err != nil {
+		return nil, err
+	}
+	h.port = port
+	h.service = service
+	return h, nil
 }
 
-//SetAddress -- Set Address. which sets address family automatically
-func (p *packerHeader) SetAddress(addr string) {
+// setAddress parses the provided address string and automatically sets the IP family.
+func (p *Header) setAddress(addr string) error {
 	p.address = net.ParseIP(addr)
 
 	if p.address.To4() != nil {
@@ -43,30 +49,33 @@ func (p *packerHeader) SetAddress(addr string) {
 	} else if p.address.To16() != nil {
 		p.family = FamilyIPv6
 	} else {
-		panic(fmt.Sprintf("setAddress does not support %q", addr))
+		return fmt.Errorf("invalid IP address %q", addr)
 	}
+	return nil
 }
 
-func (p *packerHeader) AddressBytes() []byte {
-	if ip4 := p.address.To4(); ip4 != nil {
-		p.address = ip4
-	}
-
-	return []byte(p.address)
+// Family returns the string corresponding to the address's IP family.
+func (p *Header) Family() string {
+	return addressFamilyText[p.family]
 }
 
-func (p *packerHeader) AddressString() string {
+// Address returns the string form of the header's remote address.
+func (p *Header) Address() string {
 	return p.address.String()
 }
 
-func (p *packerHeader) Address() net.IP {
-	return p.address
+// Port returns the connected port of the remote connection.
+func (p *Header) Port() int {
+	return p.port
 }
 
-func (p *packerHeader) Family() addressFamily {
-	return p.family
+// SetService overrides the header's original service. This is primarily useful
+// for sending 'error' and 'end' messages.
+func (p *Header) SetService(service string) {
+	p.service = service
 }
 
-func (p *packerHeader) FamilyText() string {
-	return addressFamilyText[p.family]
+// Service returns the service stored in the header.
+func (p *Header) Service() string {
+	return p.service
 }

rvpn/server/connection.go

@@ -2,8 +2,8 @@ package server
 
 import (
 	"context"
+	"fmt"
 	"io"
-	"strconv"
 	"sync"
 	"time"
 
@@ -252,7 +252,7 @@ func (c *Connection) Reader(ctx context.Context) {
 
 		// unpack the message.
 		p, err := packer.ReadMessage(message)
-		key := p.Header.Address().String() + ":" + strconv.Itoa(p.Header.Port)
+		key := fmt.Sprintf("%s:%d", p.Address(), p.Port())
 		track, err := connectionTrack.Lookup(key)
 
 		//loginfo.Println(hex.Dump(p.Data.Data()))

rvpn/server/listener_generic.go

@@ -18,6 +18,7 @@ import (
 	"github.com/gorilla/websocket"
 
 	"git.daplie.com/Daplie/go-rvpn-server/rvpn/packer"
+	"git.daplie.com/Daplie/go-rvpn-server/rvpn/sni"
 )
 
 type contextKey string
@@ -160,7 +161,7 @@ func handleConnection(ctx context.Context, wConn *WedgeConn) {
 		wssHostName := ctx.Value(ctxWssHostName).(string)
 		adminHostName := ctx.Value(ctxAdminHostName).(string)
 
-		sniHostName, err := getHello(peek)
+		sniHostName, err := sni.GetHostname(peek)
 		if err != nil {
 			loginfo.Println(err)
 			return
@@ -292,11 +293,19 @@ func handleExternalHTTPRequest(ctx context.Context, extConn *WedgeConn, hostname
 	track := NewTrack(extConn, hostname)
 	serverStatus.ExtConnectionRegister(track)
 
-	loginfo.Println("Domain Accepted", hostname, extConn.RemoteAddr().String())
+	remoteStr := extConn.RemoteAddr().String()
+	loginfo.Println("Domain Accepted", hostname, remoteStr)
 
-	rAddr, rPort, err := net.SplitHostPort(extConn.RemoteAddr().String())
-	if err != nil {
-		loginfo.Println("unable to decode hostport", extConn.RemoteAddr().String())
+	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
 	}
 
@@ -309,18 +318,8 @@ func handleExternalHTTPRequest(ctx context.Context, extConn *WedgeConn, hostname
 
 		loginfo.Println("Before Packer", hex.Dump(buffer))
 
-		cnt := len(buffer)
-
-		p := packer.NewPacker()
-		p.Header.SetAddress(rAddr)
-		p.Header.Port, err = strconv.Atoi(rPort)
-		if err != nil {
-			loginfo.Println("Unable to set Remote port", err)
-			return
-		}
-
-		p.Header.Service = service
-		p.Data.AppendBytes(buffer[0:cnt])
+		p := packer.NewPacker(header)
+		p.Data.AppendBytes(buffer)
 		buf := p.PackV1()
 
 		//loginfo.Println(hex.Dump(buf.Bytes()))
@@ -329,8 +328,8 @@ func handleExternalHTTPRequest(ctx context.Context, extConn *WedgeConn, hostname
 		sendTrack := NewSendTrack(buf.Bytes(), hostname)
 		serverStatus.SendExtRequest(conn, sendTrack)
 
-		_, err = extConn.Discard(cnt)
-		if err != nil {
+		cnt := len(buffer)
+		if _, err = extConn.Discard(cnt); err != nil {
 			loginfo.Println("unable to discard", cnt, err)
 			return
 		}

rvpn/sni/tls_get_hostname.go

@@ -1,10 +1,11 @@
-package server
+package sni
 
 import (
 	"errors"
 )
 
-func getHello(b []byte) (string, error) {
+// GetHostname uses SNI to determine the intended target of a new TLS connection.
+func GetHostname(b []byte) (string, error) {
 	rest := b[5:]
 	current := 0
 	handshakeType := rest[0]