Include headroom calculations (#106)

* add space in buffer to prevent overflow

* add upstream to conns

Author: thomasjib

go.mod

@@ -54,7 +54,7 @@ require (
 	github.com/oschwald/geoip2-golang v1.9.0 // indirect
 	github.com/oschwald/maxminddb-golang v1.13.1 // indirect
 	github.com/oxtoacart/bpool v0.0.0-20190530202638-03653db5a59c // indirect
-	github.com/ulikunitz/xz v0.5.10 // indirect
+	github.com/ulikunitz/xz v0.5.11 // indirect
 	github.com/xi2/xz v0.0.0-20171230120015-48954b6210f8 // indirect
 	go.opentelemetry.io/proto/otlp v1.7.1 // indirect
 	go4.org/netipx v0.0.0-20231129151722-fdeea329fbba // indirect
@@ -100,7 +100,7 @@ require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/dblohm7/wingoes v0.0.0-20240119213807-a09d6be7affa // indirect
 	github.com/digitalocean/go-smbios v0.0.0-20180907143718-390a4f403a8e // indirect
-	github.com/dustin/go-humanize v1.0.0 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/edsrzf/mmap-go v1.1.0 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
@@ -156,23 +156,22 @@ require (
 	github.com/mitchellh/go-ps v1.0.0 // indirect
 	github.com/mschoch/smat v0.2.0 // indirect
 	github.com/pierrec/lz4/v4 v4.1.21 // indirect
-	github.com/pion/datachannel v1.5.2 // indirect
+	github.com/pion/datachannel v1.5.5 // indirect
 	github.com/pion/dtls/v2 v2.2.7 // indirect
-	github.com/pion/ice/v2 v2.2.6 // indirect
-	github.com/pion/interceptor v0.1.11 // indirect
+	github.com/pion/ice/v2 v2.3.5 // indirect
+	github.com/pion/interceptor v0.1.17 // indirect
 	github.com/pion/logging v0.2.2 // indirect
-	github.com/pion/mdns v0.0.5 // indirect
+	github.com/pion/mdns v0.0.7 // indirect
 	github.com/pion/randutil v0.1.0 // indirect
-	github.com/pion/rtcp v1.2.9 // indirect
+	github.com/pion/rtcp v1.2.10 // indirect
 	github.com/pion/rtp v1.7.13 // indirect
 	github.com/pion/sctp v1.8.8 // indirect
-	github.com/pion/sdp/v3 v3.0.5 // indirect
-	github.com/pion/srtp/v2 v2.0.9 // indirect
+	github.com/pion/sdp/v3 v3.0.6 // indirect
+	github.com/pion/srtp/v2 v2.0.15 // indirect
 	github.com/pion/stun v0.6.1 // indirect
-	github.com/pion/transport v0.13.1 // indirect
 	github.com/pion/transport/v2 v2.2.3 // indirect
-	github.com/pion/turn/v2 v2.0.8 // indirect
-	github.com/pion/webrtc/v3 v3.1.42 // indirect
+	github.com/pion/turn/v2 v2.1.0 // indirect
+	github.com/pion/webrtc/v3 v3.2.6 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus-community/pro-bing v0.4.0 // indirect

go.sum

@@ -166,6 +166,10 @@ func (c *writeConn) sendInfo(conn net.Conn) error {
 	return nil
 }
 
+func (c *writeConn) Upstream() any {
+	return c.Conn
+}
+
 type writePacketConn struct {
 	N.PacketConn
 	metadata      adapter.InboundContext
@@ -246,3 +250,7 @@ func (c *writePacketConn) sendInfo(conn net.PacketConn) error {
 	}
 	return nil
 }
+
+func (c *writePacketConn) Upstream() any {
+	return c.PacketConn
+}

tracker/clientcontext/injector.go

@@ -174,6 +174,10 @@ func (c *readConn) readInfo() (*ClientInfo, error) {
 	return &info, nil
 }
 
+func (c *readConn) Upstream() any {
+	return c.Conn
+}
+
 type readPacketConn struct {
 	N.PacketConn
 	mgr         *Manager
@@ -214,11 +218,22 @@ func (c *readPacketConn) readInfo() (*ClientInfo, error) {
 	// CRITICAL: Use a new buffer for the response to ensure we have enough headroom
 	// for the packet headers (e.g. VMess). Reusing the old buffer with Reset()
 	// discards the headroom and causes 'buffer overflow' panics.
+	// advance buffer start, and reserve end, to leave room for headers/trailers on various protocols
 	respBuffer := buf.NewPacket()
 	defer respBuffer.Release()
+
+	headroom := N.CalculateFrontHeadroom(c)
+	rearHeadroom := N.CalculateRearHeadroom(c)
+	respBuffer.Advance(headroom)
+	respBuffer.Reserve(rearHeadroom)
+
 	respBuffer.WriteString("OK")
 	if err := c.WritePacket(respBuffer, destination); err != nil {
 		return nil, fmt.Errorf("writing OK response: %w", err)
 	}
 	return &info, nil
 }
+
+func (c *readPacketConn) Upstream() any {
+	return c.PacketConn
+}

tracker/clientcontext/manager.go

@@ -241,3 +241,7 @@ func (c *Conn) GetStatus() (*DataCapStatus, error) {
 func (c *Conn) GetBytesConsumed() int64 {
 	return c.bytesSent.Load() + c.bytesReceived.Load()
 }
+
+func (c *Conn) Upstream() any {
+	return c.Conn
+}

tracker/datacap/conn.go

@@ -238,3 +238,7 @@ func (c *PacketConn) GetStatus() (*DataCapStatus, error) {
 func (c *PacketConn) GetBytesConsumed() int64 {
 	return c.bytesSent.Load() + c.bytesReceived.Load()
 }
+
+func (c *PacketConn) Upstream() any {
+	return c.PacketConn
+}

tracker/datacap/packet_conn.go

@@ -55,3 +55,7 @@ func (c *Conn) Close() error {
 	metrics.conns.Add(context.Background(), -1, metric.WithAttributes(c.attributes...))
 	return c.Conn.Close()
 }
+
+func (c *Conn) Upstream() any {
+	return c.Conn
+}

tracker/metrics/conn.go

@@ -18,11 +18,12 @@ import (
 )
 
 type metricsManager struct {
-	meter         metric.Meter
-	ProxyIO       metric.Int64Counter
-	Connections   metric.Int64Counter
-	conns         metric.Int64UpDownCounter
-	duration      metric.Int64Histogram
+	meter       metric.Meter
+	ProxyIO     metric.Int64Counter
+	Connections metric.Int64Counter
+	conns       metric.Int64UpDownCounter
+	duration    metric.Int64Histogram
+
 	countryLookup geo.CountryLookup
 }
 

tracker/metrics/metrics.go

@@ -60,3 +60,7 @@ func (c *PacketConn) Close() error {
 	metrics.conns.Add(context.Background(), -1, metric.WithAttributes(c.attributes...))
 	return c.PacketConn.Close()
 }
+
+func (c *PacketConn) Upstream() any {
+	return c.PacketConn
+}

tracker/metrics/packet_conn.go

@@ -82,7 +82,6 @@ func TestTracker(t *testing.T) {
 	if results["receive"] != int64(serverReceive) {
 		t.Errorf("receive bytes did not match, got %d, want %d", results["receive"], serverReceive)
 	}
-
 }
 
 func extractCountersByAttribute(rm metricdata.ResourceMetrics, name string) map[string]int64 {