Moved most files of the client into a subdirectory, to reduce need for patching for use in IPtProxy.

dnstt-client/lib/dns.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"bytes"
@@ -16,8 +16,8 @@ import (
 )
 
 const (
-	// How many bytes of random padding to insert into queries.
-	numPadding = 3
+	// NumPadding How many bytes of random padding to insert into queries.
+	NumPadding = 3
 	// In an otherwise empty polling query, insert even more random padding,
 	// to reduce the chance of a cache hit. Cannot be greater than 31,
 	// because the prefix codes indicating padding start at 224.
@@ -39,8 +39,8 @@ const (
 	pollLimit = 16
 )
 
-// base32Encoding is a base32 encoding without padding.
-var base32Encoding = base32.StdEncoding.WithPadding(base32.NoPadding)
+// Base32Encoding is a base32 encoding without padding.
+var Base32Encoding = base32.StdEncoding.WithPadding(base32.NoPadding)
 
 // DNSPacketConn provides a packet-sending and -receiving interface over various
 // forms of DNS. It handles the details of how packets and padding are encoded
@@ -187,6 +187,7 @@ func (c *DNSPacketConn) recvLoop(transport net.PacketConn) error {
 		var buf [4096]byte
 		n, addr, err := transport.ReadFrom(buf[:])
 		if err != nil {
+			//goland:noinspection GoDeprecation
 			if err, ok := err.(net.Error); ok && err.Temporary() {
 				log.Printf("ReadFrom temporary error: %v", err)
 				continue
@@ -205,13 +206,13 @@ func (c *DNSPacketConn) recvLoop(transport net.PacketConn) error {
 
 		// Pull out the packets contained in the payload.
 		r := bytes.NewReader(payload)
-		any := false
+		anyPacket := false
 		for {
 			p, err := nextPacket(r)
 			if err != nil {
 				break
 			}
-			any = true
+			anyPacket = true
 			c.QueuePacketConn.QueueIncoming(p, addr)
 		}
 
@@ -219,7 +220,7 @@ func (c *DNSPacketConn) recvLoop(transport net.PacketConn) error {
 		// to poll immediately. ACKs on received data will effectively
 		// serve as another stream of polls whose rate is proportional
 		// to the rate of incoming packets.
-		if any {
+		if anyPacket {
 			select {
 			case c.pollChan <- struct{}{}:
 			default:
@@ -228,9 +229,9 @@ func (c *DNSPacketConn) recvLoop(transport net.PacketConn) error {
 	}
 }
 
-// chunks breaks p into non-empty subslices of at most n bytes, greedily so that
+// Chunks breaks p into non-empty subslices of at most n bytes, greedily so that
 // only final subslice has length < n.
-func chunks(p []byte, n int) [][]byte {
+func Chunks(p []byte, n int) [][]byte {
 	var result [][]byte
 	for len(p) > 0 {
 		sz := len(p)
@@ -274,13 +275,13 @@ func (c *DNSPacketConn) send(transport net.PacketConn, p []byte, addr net.Addr)
 		var buf bytes.Buffer
 		// ClientID
 		buf.Write(c.clientID[:])
-		n := numPadding
+		n := NumPadding
 		if len(p) == 0 {
 			n = numPaddingForPoll
 		}
 		// Padding / cache inhibition
 		buf.WriteByte(byte(224 + n))
-		io.CopyN(&buf, rand.Reader, int64(n))
+		_, _ = io.CopyN(&buf, rand.Reader, int64(n))
 		// Packet contents
 		if len(p) > 0 {
 			buf.WriteByte(byte(len(p)))
@@ -289,10 +290,10 @@ func (c *DNSPacketConn) send(transport net.PacketConn, p []byte, addr net.Addr)
 		decoded = buf.Bytes()
 	}
 
-	encoded := make([]byte, base32Encoding.EncodedLen(len(decoded)))
-	base32Encoding.Encode(encoded, decoded)
+	encoded := make([]byte, Base32Encoding.EncodedLen(len(decoded)))
+	Base32Encoding.Encode(encoded, decoded)
 	encoded = bytes.ToLower(encoded)
-	labels := chunks(encoded, 63)
+	labels := Chunks(encoded, 63)
 	labels = append(labels, c.domain...)
 	name, err := dns.NewName(labels)
 	if err != nil {
@@ -300,7 +301,7 @@ func (c *DNSPacketConn) send(transport net.PacketConn, p []byte, addr net.Addr)
 	}
 
 	var id uint16
-	binary.Read(rand.Reader, binary.BigEndian, &id)
+	_ = binary.Read(rand.Reader, binary.BigEndian, &id)
 	query := &dns.Message{
 		ID:    id,
 		Flags: 0x0100, // QR = 0, RD = 1

dnstt-client/lib/dns_test.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"bytes"

dnstt-client/lib/http.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"bytes"
@@ -88,7 +88,9 @@ func (c *HTTPPacketConn) send(p []byte) error {
 	if err != nil {
 		return err
 	}
-	defer resp.Body.Close()
+	defer func() {
+		_ = resp.Body.Close()
+	}()
 
 	switch resp.StatusCode {
 	case http.StatusOK:

dnstt-client/lib/http_test.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"testing"

dnstt-client/lib/tls.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"bufio"
@@ -54,7 +54,9 @@ func NewTLSPacketConn(addr string, dialTLSContext func(ctx context.Context, netw
 		QueuePacketConn: turbotunnel.NewQueuePacketConn(turbotunnel.DummyAddr{}, 0),
 	}
 	go func() {
-		defer c.Close()
+		defer func() {
+			_ = c.Close()
+		}()
 		for {
 			var wg sync.WaitGroup
 			wg.Add(2)
@@ -73,7 +75,7 @@ func NewTLSPacketConn(addr string, dialTLSContext func(ctx context.Context, netw
 				wg.Done()
 			}()
 			wg.Wait()
-			conn.Close()
+			_ = conn.Close()
 
 			// Whenever the TLS connection dies, redial a new one.
 			conn, err = dial()

dnstt-client/lib/utls.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 // Support code for TLS camouflage using uTLS.
 
@@ -16,9 +16,9 @@ import (
 	"golang.org/x/net/http2"
 )
 
-// utlsClientHelloIDMap is a correspondence between human-readable labels and
+// UtlsClientHelloIDMap is a correspondence between human-readable labels and
 // supported utls.ClientHelloIDs.
-var utlsClientHelloIDMap = []struct {
+var UtlsClientHelloIDMap = []struct {
 	Label string
 	ID    *utls.ClientHelloID
 }{
@@ -38,10 +38,10 @@ var utlsClientHelloIDMap = []struct {
 	{"iOS_12_1", &utls.HelloIOS_12_1},
 }
 
-// utlsLookup returns a *utls.ClientHelloID from utlsClientHelloIDMap by a
+// UtlsLookup returns a *utls.ClientHelloID from utlsClientHelloIDMap by a
 // case-insensitive label match, or nil if there is no match.
-func utlsLookup(label string) *utls.ClientHelloID {
-	for _, entry := range utlsClientHelloIDMap {
+func UtlsLookup(label string) *utls.ClientHelloID {
+	for _, entry := range UtlsClientHelloIDMap {
 		if strings.ToLower(label) == strings.ToLower(entry.Label) {
 			return entry.ID
 		}
@@ -49,10 +49,10 @@ func utlsLookup(label string) *utls.ClientHelloID {
 	return nil
 }
 
-// utlsDialContext connects to the given network address and initiates a TLS
+// UtlsDialContext connects to the given network address and initiates a TLS
 // handshake with the provided ClientHelloID, and returns the resulting TLS
 // connection.
-func utlsDialContext(ctx context.Context, network, addr string, config *utls.Config, id *utls.ClientHelloID) (*utls.UConn, error) {
+func UtlsDialContext(ctx context.Context, network, addr string, config *utls.Config, id *utls.ClientHelloID) (*utls.UConn, error) {
 	// Set the SNI from addr, if not already set.
 	if config == nil {
 		config = &utls.Config{}
@@ -76,7 +76,7 @@ func utlsDialContext(ctx context.Context, network, addr string, config *utls.Con
 	if net.ParseIP(config.ServerName) != nil {
 		err := uconn.RemoveSNIExtension()
 		if err != nil {
-			uconn.Close()
+			_ = uconn.Close()
 			return nil, err
 		}
 	}
@@ -88,7 +88,7 @@ func utlsDialContext(ctx context.Context, network, addr string, config *utls.Con
 	// https://github.com/refraction-networking/utls/issues/75
 	err = uconn.Handshake()
 	if err != nil {
-		uconn.Close()
+		_ = uconn.Close()
 		return nil, err
 	}
 	return uconn, nil
@@ -186,7 +186,7 @@ func makeRoundTripper(req *http.Request, config *utls.Config, id *utls.ClientHel
 		return nil, err
 	}
 
-	bootstrapConn, err := utlsDialContext(req.Context(), "tcp", addr, config, id)
+	bootstrapConn, err := UtlsDialContext(req.Context(), "tcp", addr, config, id)
 	if err != nil {
 		return nil, err
 	}
@@ -210,7 +210,7 @@ func makeRoundTripper(req *http.Request, config *utls.Config, id *utls.ClientHel
 		}
 
 		// Later dials make a new connection.
-		uconn, err := utlsDialContext(ctx, "tcp", addr, config, id)
+		uconn, err := UtlsDialContext(ctx, "tcp", addr, config, id)
 		if err != nil {
 			return nil, err
 		}

dnstt-client/lib/weightedlist.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 // Random selection from weighted distributions, and strings for specifying such
 // distributions.
@@ -12,7 +12,7 @@ import (
 	"strings"
 )
 
-// parseWeightedList parses a list of text labels with optional numeric weights,
+// ParseWeightedList parses a list of text labels with optional numeric weights,
 // and returns parallel slices of weights and labels. If a weight is omitted for
 // a label, the weight is 1.
 //
@@ -22,7 +22,7 @@ import (
 //
 //   list ::= entry ("," entry)*
 //   entry ::= (weight "*")? label
-func parseWeightedList(s string) ([]uint32, []string, error) {
+func ParseWeightedList(s string) ([]uint32, []string, error) {
 	const (
 		kindEOF = iota
 		kindComma
@@ -176,10 +176,10 @@ func (s cryptoSource) Int63() int64 {
 	return n
 }
 
-// sampleWeighted returns the index of a randomly selected element of the
+// SampleWeighted returns the index of a randomly selected element of the
 // weights slice, weighted by the values stored in the slice. Panics if
 // the sum of the weights is zero or does not fit in an int64.
-func sampleWeighted(weights []uint32) int {
+func SampleWeighted(weights []uint32) int {
 	var sum int64 = 0
 	for _, w := range weights {
 		sum += int64(w)

dnstt-client/lib/weightedlist_test.go

@@ -1,4 +1,4 @@
-package main
+package dnstt_client
 
 import (
 	"testing"
@@ -20,7 +20,7 @@ func TestParseWeightedList(t *testing.T) {
 		{"\\,", []uint32{1}, []string{","}},
 		{"3\\*apple\\,car\\rot,100*orange", []uint32{1, 100}, []string{"3*apple,carrot", "orange"}},
 	} {
-		weights, labels, err := parseWeightedList(test.input)
+		weights, labels, err := ParseWeightedList(test.input)
 		if err != nil {
 			t.Errorf("%+q resulted in error: %v", test.input, err)
 			continue
@@ -55,7 +55,7 @@ func TestParseWeightedList(t *testing.T) {
 		"-5*apple",
 		"5.5*apple",
 	} {
-		_, _, err := parseWeightedList(input)
+		_, _, err := ParseWeightedList(input)
 		if err == nil {
 			t.Errorf("%+q resulted in no error", input)
 			continue
@@ -77,7 +77,7 @@ func TestSampleWeighted(t *testing.T) {
 					t.Errorf("%v: expected panic", weights)
 				}
 			}()
-			sampleWeighted(weights)
+			SampleWeighted(weights)
 		}()
 	}
 
@@ -92,7 +92,7 @@ func TestSampleWeighted(t *testing.T) {
 		{[]uint32{0, 0, 0xffffffff, 0, 1}, 2},
 	} {
 		for i := 0; i < 100; i++ {
-			index := sampleWeighted(test.weights)
+			index := SampleWeighted(test.weights)
 			if index != test.index {
 				t.Errorf("%v: expected %d, got %d", test.weights, test.index, index)
 			}

dnstt-client/main.go

@@ -48,6 +48,7 @@ import (
 	"sync"
 	"syscall"
 	"time"
+	dc "www.bamsoftware.com/git/dnstt.git/dnstt-client/lib"
 
 	utls "github.com/refraction-networking/utls"
 	"github.com/xtaci/kcp-go/v5"
@@ -99,7 +100,7 @@ func readKeyFromFile(filename string) ([]byte, error) {
 // utls.ClientHelloID from utlsClientHelloIDMap, and randomly samples one
 // utls.ClientHelloID from the distribution.
 func sampleUTLSDistribution(spec string) (*utls.ClientHelloID, error) {
-	weights, labels, err := parseWeightedList(spec)
+	weights, labels, err := dc.ParseWeightedList(spec)
 	if err != nil {
 		return nil, err
 	}
@@ -109,14 +110,14 @@ func sampleUTLSDistribution(spec string) (*utls.ClientHelloID, error) {
 		if label == "none" {
 			id = nil
 		} else {
-			id = utlsLookup(label)
+			id = dc.UtlsLookup(label)
 			if id == nil {
 				return nil, fmt.Errorf("unknown TLS fingerprint %q", label)
 			}
 		}
 		ids = append(ids, id)
 	}
-	return ids[sampleWeighted(weights)], nil
+	return ids[dc.SampleWeighted(weights)], nil
 }
 
 func handle(local *net.TCPConn, sess *smux.Session, conv uint32) error {
@@ -170,7 +171,7 @@ func listen(pubkey []byte, domain dns.Name, remoteAddr net.Addr, pconn net.Packe
 		return nil, nil, nil, fmt.Errorf("opening local listener: %v", err)
 	}
 
-	mtu := dnsNameCapacity(domain) - 8 - 1 - numPadding - 1 // clientid + padding length prefix + padding + data length prefix
+	mtu := dnsNameCapacity(domain) - 8 - 1 - dc.NumPadding - 1 // clientid + padding length prefix + padding + data length prefix
 	if mtu < 80 {
 		_ = pconn.Close()
 		_ = ln.Close()
@@ -244,6 +245,7 @@ func acceptLoop(ln *pt.SocksListener, pconn net.PacketConn, conn *kcp.UDPSession
 	for {
 		local, err := ln.AcceptSocks()
 		if err != nil {
+			//goland:noinspection GoDeprecation
 			if err, ok := err.(net.Error); ok && err.Temporary() {
 				continue
 			}
@@ -308,9 +310,9 @@ Examples:
 
 `, os.Args[0])
 		flag.PrintDefaults()
-		labels := make([]string, 0, len(utlsClientHelloIDMap))
+		labels := make([]string, 0, len(dc.UtlsClientHelloIDMap))
 		labels = append(labels, "none")
-		for _, entry := range utlsClientHelloIDMap {
+		for _, entry := range dc.UtlsClientHelloIDMap {
 			labels = append(labels, entry.Label)
 		}
 		_, _ = fmt.Fprintf(flag.CommandLine.Output(), `
@@ -407,9 +409,9 @@ Known TLS fingerprints for -utls are:
 				transport.Proxy = nil
 				rt = transport
 			} else {
-				rt = NewUTLSRoundTripper(nil, utlsClientHelloID)
+				rt = dc.NewUTLSRoundTripper(nil, utlsClientHelloID)
 			}
-			pconn, err := NewHTTPPacketConn(rt, dohURL, 32)
+			pconn, err := dc.NewHTTPPacketConn(rt, dohURL, 32)
 			return addr, pconn, err
 		}},
 		// -dot
@@ -420,10 +422,10 @@ Known TLS fingerprints for -utls are:
 				dialTLSContext = (&tls.Dialer{}).DialContext
 			} else {
 				dialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-					return utlsDialContext(ctx, network, addr, nil, utlsClientHelloID)
+					return dc.UtlsDialContext(ctx, network, addr, nil, utlsClientHelloID)
 				}
 			}
-			pconn, err := NewTLSPacketConn(dotAddr, dialTLSContext)
+			pconn, err := dc.NewTLSPacketConn(dotAddr, dialTLSContext)
 			return addr, pconn, err
 		}},
 		// -udp
@@ -473,7 +475,7 @@ Known TLS fingerprints for -utls are:
 	for _, methodName := range ptInfo.MethodNames {
 		switch methodName {
 		case "dnstt":
-			pconn = NewDNSPacketConn(pconn, remoteAddr, domain)
+			pconn = dc.NewDNSPacketConn(pconn, remoteAddr, domain)
 			ln, conn, sess, err := listen(pubkey, domain, remoteAddr, pconn)
 			if err != nil {
 				_ = pt.CmethodError(methodName, err.Error())

dnstt-client/main_test.go

@@ -3,13 +3,14 @@ package main
 import (
 	"bytes"
 	"testing"
+	dc "www.bamsoftware.com/git/dnstt.git/dnstt-client/lib"
 
 	"www.bamsoftware.com/git/dnstt.git/dns"
 )
 
 func TestDNSNameCapacity(t *testing.T) {
 	for domainLen := 0; domainLen < 255; domainLen++ {
-		domain, err := dns.NewName(chunks(bytes.Repeat([]byte{'x'}, domainLen), 63))
+		domain, err := dns.NewName(dc.Chunks(bytes.Repeat([]byte{'x'}, domainLen), 63))
 		if err != nil {
 			continue
 		}
@@ -17,8 +18,8 @@ func TestDNSNameCapacity(t *testing.T) {
 		if capacity <= 0 {
 			continue
 		}
-		prefix := []byte(base32Encoding.EncodeToString(bytes.Repeat([]byte{'y'}, capacity)))
-		labels := append(chunks(prefix, 63), domain...)
+		prefix := []byte(dc.Base32Encoding.EncodeToString(bytes.Repeat([]byte{'y'}, capacity)))
+		labels := append(dc.Chunks(prefix, 63), domain...)
 		_, err = dns.NewName(labels)
 		if err != nil {
 			t.Errorf("length %v  capacity %v  %v", domainLen, capacity, err)