From: Matt Joiner <anacrolix@gmail.com>
Date: Wed, 3 May 2023 06:40:00 +0000 (+1000)
Subject: Add many more extension bit definitions
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=c202126a62ff9c321fcb9f7bb037bb5f1b52e216;p=btrtrc.git

Add many more extension bit definitions
---

diff --git a/global.go b/global.go
index dfb6bd4c..5a5bddba 100644
--- a/global.go
+++ b/global.go
@@ -28,7 +28,7 @@ const (
 )
 
 func defaultPeerExtensionBytes() PeerExtensionBits {
-	return pp.NewPeerExtensionBytes(pp.ExtensionBitDHT, pp.ExtensionBitExtended, pp.ExtensionBitFast)
+	return pp.NewPeerExtensionBytes(pp.ExtensionBitDht, pp.ExtensionBitLtep, pp.ExtensionBitFast)
 }
 
 func init() {
diff --git a/peer_protocol/handshake.go b/peer_protocol/handshake.go
index 76dc2b05..454cc246 100644
--- a/peer_protocol/handshake.go
+++ b/peer_protocol/handshake.go
@@ -15,10 +15,20 @@ import (
 
 type ExtensionBit uint
 
+// https://www.bittorrent.org/beps/bep_0004.html
+// https://wiki.theory.org/BitTorrentSpecification.html#Reserved_Bytes
 const (
-	ExtensionBitDHT      = 0  // http://www.bittorrent.org/beps/bep_0005.html
-	ExtensionBitExtended = 20 // http://www.bittorrent.org/beps/bep_0010.html
-	ExtensionBitFast     = 2  // http://www.bittorrent.org/beps/bep_0006.html
+	ExtensionBitDht                          = 0 // http://www.bittorrent.org/beps/bep_0005.html
+	ExtensionBitFast                         = 2 // http://www.bittorrent.org/beps/bep_0006.html
+	ExtensionBitV2                           = 7 // "Hybrid torrent legacy to v2 upgrade"
+	ExtensionBitAzureusExtensionNegotiation1 = 16
+	ExtensionBitAzureusExtensionNegotiation2 = 17
+	// LibTorrent Extension Protocol, http://www.bittorrent.org/beps/bep_0010.html
+	ExtensionBitLtep = 20
+	// https://wiki.theory.org/BitTorrent_Location-aware_Protocol_1
+	ExtensionBitLocationAwareProtocol    = 43
+	ExtensionBitAzureusMessagingProtocol = 63 // https://www.bittorrent.org/beps/bep_0004.html
+
 )
 
 func handshakeWriter(w io.Writer, bb <-chan []byte, done chan<- error) {
@@ -40,10 +50,15 @@ var bitTags = []struct {
 	bit ExtensionBit
 	tag string
 }{
-	// Ordered by their base protocol type values (PORT, fast.., EXTENDED)
-	{ExtensionBitDHT, "dht"},
+	// Ordered by their bit position left to right.
+	{ExtensionBitAzureusMessagingProtocol, "amp"},
+	{ExtensionBitLocationAwareProtocol, "loc"},
+	{ExtensionBitLtep, "ltep"},
+	{ExtensionBitAzureusExtensionNegotiation2, "azen2"},
+	{ExtensionBitAzureusExtensionNegotiation1, "azen1"},
+	{ExtensionBitV2, "v2"},
 	{ExtensionBitFast, "fast"},
-	{ExtensionBitExtended, "ext"},
+	{ExtensionBitDht, "dht"},
 }
 
 func (pex PeerExtensionBits) String() string {
@@ -71,11 +86,11 @@ func NewPeerExtensionBytes(bits ...ExtensionBit) (ret PeerExtensionBits) {
 }
 
 func (pex PeerExtensionBits) SupportsExtended() bool {
-	return pex.GetBit(ExtensionBitExtended)
+	return pex.GetBit(ExtensionBitLtep)
 }
 
 func (pex PeerExtensionBits) SupportsDHT() bool {
-	return pex.GetBit(ExtensionBitDHT)
+	return pex.GetBit(ExtensionBitDht)
 }
 
 func (pex PeerExtensionBits) SupportsFast() bool {
diff --git a/peerconn.go b/peerconn.go
index d85d0d51..1443a7b9 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -69,7 +69,7 @@ type PeerConn struct {
 }
 
 func (cn *PeerConn) pexStatus() string {
-	if !cn.bitExtensionEnabled(pp.ExtensionBitExtended) {
+	if !cn.bitExtensionEnabled(pp.ExtensionBitLtep) {
 		return "extended protocol disabled"
 	}
 	if cn.PeerExtensionIDs == nil {
diff --git a/torrent_test.go b/torrent_test.go
index b62be706..808947e9 100644
--- a/torrent_test.go
+++ b/torrent_test.go
@@ -184,10 +184,10 @@ func TestTorrentMetainfoIncompleteMetadata(t *testing.T) {
 	defer nc.Close()
 
 	var pex PeerExtensionBits
-	pex.SetBit(pp.ExtensionBitExtended, true)
+	pex.SetBit(pp.ExtensionBitLtep, true)
 	hr, err := pp.Handshake(nc, &ih, [20]byte{}, pex)
 	require.NoError(t, err)
-	assert.True(t, hr.PeerExtensionBits.GetBit(pp.ExtensionBitExtended))
+	assert.True(t, hr.PeerExtensionBits.GetBit(pp.ExtensionBitLtep))
 	assert.EqualValues(t, cl.PeerID(), hr.PeerID)
 	assert.EqualValues(t, ih, hr.Hash)