Merge release-20200810.0-23-g47515f475 (automated)

3 files changed, 22 insertions, 27 deletions

diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 46702906b..290172ac9 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -746,11 +746,7 @@ func (e *endpoint) sendTCP(r *stack.Route, tf tcpFields, data buffer.VectorisedV
 
 func buildTCPHdr(r *stack.Route, tf tcpFields, pkt *stack.PacketBuffer, gso *stack.GSO) {
 	optLen := len(tf.opts)
-	hdr := &pkt.Header
-	packetSize := pkt.Data.Size()
-	// Initialize the header.
-	tcp := header.TCP(hdr.Prepend(header.TCPMinimumSize + optLen))
-	pkt.TransportHeader = buffer.View(tcp)
+	tcp := header.TCP(pkt.TransportHeader().Push(header.TCPMinimumSize + optLen))
 	tcp.Encode(&header.TCPFields{
 		SrcPort:    tf.id.LocalPort,
 		DstPort:    tf.id.RemotePort,
@@ -762,8 +758,7 @@ func buildTCPHdr(r *stack.Route, tf tcpFields, pkt *stack.PacketBuffer, gso *sta
 	})
 	copy(tcp[header.TCPMinimumSize:], tf.opts)
 
-	length := uint16(hdr.UsedLength() + packetSize)
-	xsum := r.PseudoHeaderChecksum(ProtocolNumber, length)
+	xsum := r.PseudoHeaderChecksum(ProtocolNumber, uint16(pkt.Size()))
 	// Only calculate the checksum if offloading isn't supported.
 	if gso != nil && gso.NeedsCsum {
 		// This is called CHECKSUM_PARTIAL in the Linux kernel. We
@@ -801,17 +796,18 @@ func sendTCPBatch(r *stack.Route, tf tcpFields, data buffer.VectorisedView, gso
 			packetSize = size
 		}
 		size -= packetSize
-		var pkt stack.PacketBuffer
-		pkt.Header = buffer.NewPrependable(hdrSize)
+		pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+			ReserveHeaderBytes: hdrSize,
+		})
 		pkt.Hash = tf.txHash
 		pkt.Owner = owner
 		pkt.EgressRoute = r
 		pkt.GSOOptions = gso
 		pkt.NetworkProtocolNumber = r.NetworkProtocolNumber()
 		data.ReadToVV(&pkt.Data, packetSize)
-		buildTCPHdr(r, tf, &pkt, gso)
+		buildTCPHdr(r, tf, pkt, gso)
 		tf.seq = tf.seq.Add(seqnum.Size(packetSize))
-		pkts.PushBack(&pkt)
+		pkts.PushBack(pkt)
 	}
 
 	if tf.ttl == 0 {
@@ -837,12 +833,12 @@ func sendTCP(r *stack.Route, tf tcpFields, data buffer.VectorisedView, gso *stac
 		return sendTCPBatch(r, tf, data, gso, owner)
 	}
 
-	pkt := &stack.PacketBuffer{
-		Header: buffer.NewPrependable(header.TCPMinimumSize + int(r.MaxHeaderLength()) + optLen),
-		Data:   data,
-		Hash:   tf.txHash,
-		Owner:  owner,
-	}
+	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
+		ReserveHeaderBytes: header.TCPMinimumSize + int(r.MaxHeaderLength()) + optLen,
+		Data:               data,
+	})
+	pkt.Hash = tf.txHash
+	pkt.Owner = owner
 	buildTCPHdr(r, tf, pkt, gso)
 
 	if tf.ttl == 0 {
diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index 49a673b42..c5afa2680 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -21,7 +21,6 @@
 package tcp
 
 import (
-	"fmt"
 	"runtime"
 	"strings"
 	"time"
@@ -547,22 +546,22 @@ func (p *protocol) SynRcvdCounter() *synRcvdCounter {
 
 // Parse implements stack.TransportProtocol.Parse.
 func (*protocol) Parse(pkt *stack.PacketBuffer) bool {
-	hdr, ok := pkt.Data.PullUp(header.TCPMinimumSize)
+	// TCP header is variable length, peek at it first.
+	hdrLen := header.TCPMinimumSize
+	hdr, ok := pkt.Data.PullUp(hdrLen)
 	if !ok {
 		return false
 	}
 
 	// If the header has options, pull those up as well.
 	if offset := int(header.TCP(hdr).DataOffset()); offset > header.TCPMinimumSize && offset <= pkt.Data.Size() {
-		hdr, ok = pkt.Data.PullUp(offset)
-		if !ok {
-			panic(fmt.Sprintf("There should be at least %d bytes in pkt.Data.", offset))
-		}
+		// TODO(gvisor.dev/issue/2404): Figure out whether to reject this kind of
+		// packets.
+		hdrLen = offset
 	}
 
-	pkt.TransportHeader = hdr
-	pkt.Data.TrimFront(len(hdr))
-	return true
+	_, ok = pkt.TransportHeader().Consume(hdrLen)
+	return ok
 }
 
 // NewProtocol returns a TCP transport protocol.
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index bb60dc29d..94307d31a 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -68,7 +68,7 @@ func newSegment(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketB
 		route:  r.Clone(),
 	}
 	s.data = pkt.Data.Clone(s.views[:])
-	s.hdr = header.TCP(pkt.TransportHeader)
+	s.hdr = header.TCP(pkt.TransportHeader().View())
 	s.rcvdTime = time.Now()
 	return s
 }