Add many more extension bit definitions

anacrolix · May 9, 2023 · c202126 · c202126
1 parent e9e21b9
commit c202126
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Showing 4 changed files with 27 additions and 12 deletions.
diff --git 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
@@ -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
@@ -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
@@ -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)