RACK: Create a new list for segments.

RACK requires the segments to be in the order of their transmission
or retransmission times. This cl creates a new list and moves the
retransmitted segments to the end of the list.

PiperOrigin-RevId: 327325153

1 files changed, 17 insertions, 6 deletions

diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index 94307d31a..a20755f78 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -30,12 +30,13 @@ import (
 //
 // +stateify savable
 type segment struct {
-	segmentEntry
-	refCnt int32
-	id     stack.TransportEndpointID `state:"manual"`
-	route  stack.Route               `state:"manual"`
-	data   buffer.VectorisedView     `state:".(buffer.VectorisedView)"`
-	hdr    header.TCP
+	segEntry     segmentEntry
+	rackSegEntry rackSegmentEntry
+	refCnt       int32
+	id           stack.TransportEndpointID `state:"manual"`
+	route        stack.Route               `state:"manual"`
+	data         buffer.VectorisedView     `state:".(buffer.VectorisedView)"`
+	hdr          header.TCP
 	// views is used as buffer for data when its length is large
 	// enough to store a VectorisedView.
 	views [8]buffer.View `state:"nosave"`
@@ -61,6 +62,16 @@ type segment struct {
 	xmitCount uint32
 }
 
+// segmentMapper is the ElementMapper for the writeList.
+type segmentMapper struct{}
+
+func (segmentMapper) linkerFor(seg *segment) *segmentEntry { return &seg.segEntry }
+
+// rackSegmentMapper is the ElementMapper for the rcList.
+type rackSegmentMapper struct{}
+
+func (rackSegmentMapper) linkerFor(seg *segment) *rackSegmentEntry { return &seg.rackSegEntry }
+
 func newSegment(r *stack.Route, id stack.TransportEndpointID, pkt *stack.PacketBuffer) *segment {
 	s := &segment{
 		refCnt: 1,