diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/BUILD | 12 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/segment.go | 9 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/segment_test.go | 67 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/snd.go | 11 |
4 files changed, 91 insertions, 8 deletions
diff --git a/pkg/tcpip/transport/tcp/BUILD b/pkg/tcpip/transport/tcp/BUILD index 48417f192..0f20d3856 100644 --- a/pkg/tcpip/transport/tcp/BUILD +++ b/pkg/tcpip/transport/tcp/BUILD @@ -126,7 +126,15 @@ go_test( go_test( name = "tcp_test", size = "small", - srcs = ["timer_test.go"], + srcs = [ + "segment_test.go", + "timer_test.go", + ], library = ":tcp", - deps = ["//pkg/sleep"], + deps = [ + "//pkg/sleep", + "//pkg/tcpip/buffer", + "//pkg/tcpip/stack", + "@com_github_google_go_cmp//cmp:go_default_library", + ], ) diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go index c28641be3..7e5ba6ef7 100644 --- a/pkg/tcpip/transport/tcp/segment.go +++ b/pkg/tcpip/transport/tcp/segment.go @@ -140,6 +140,15 @@ func (s *segment) clone() *segment { return t } +// merge merges data in oth and clears oth. +func (s *segment) merge(oth *segment) { + s.data.Append(oth.data) + s.dataMemSize = s.data.Size() + + oth.data = buffer.VectorisedView{} + oth.dataMemSize = oth.data.Size() +} + // flagIsSet checks if at least one flag in flags is set in s.flags. func (s *segment) flagIsSet(flags header.TCPFlags) bool { return s.flags&flags != 0 diff --git a/pkg/tcpip/transport/tcp/segment_test.go b/pkg/tcpip/transport/tcp/segment_test.go new file mode 100644 index 000000000..486016fc0 --- /dev/null +++ b/pkg/tcpip/transport/tcp/segment_test.go @@ -0,0 +1,67 @@ +// Copyright 2021 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package tcp + +import ( + "testing" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/stack" +) + +type segmentSizeWants struct { + DataSize int + SegMemSize int +} + +func checkSegmentSize(t *testing.T, name string, seg *segment, want segmentSizeWants) { + t.Helper() + got := segmentSizeWants{ + DataSize: seg.data.Size(), + SegMemSize: seg.segMemSize(), + } + if diff := cmp.Diff(got, want); diff != "" { + t.Errorf("%s differs (-want +got):\n%s", name, diff) + } +} + +func TestSegmentMerge(t *testing.T) { + id := stack.TransportEndpointID{} + seg1 := newOutgoingSegment(id, buffer.NewView(10)) + defer seg1.decRef() + seg2 := newOutgoingSegment(id, buffer.NewView(20)) + defer seg2.decRef() + + checkSegmentSize(t, "seg1", seg1, segmentSizeWants{ + DataSize: 10, + SegMemSize: SegSize + 10, + }) + checkSegmentSize(t, "seg2", seg2, segmentSizeWants{ + DataSize: 20, + SegMemSize: SegSize + 20, + }) + + seg1.merge(seg2) + + checkSegmentSize(t, "seg1", seg1, segmentSizeWants{ + DataSize: 30, + SegMemSize: SegSize + 30, + }) + checkSegmentSize(t, "seg2", seg2, segmentSizeWants{ + DataSize: 0, + SegMemSize: SegSize, + }) +} diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go index 2b32cb7b2..f43e86677 100644 --- a/pkg/tcpip/transport/tcp/snd.go +++ b/pkg/tcpip/transport/tcp/snd.go @@ -716,15 +716,14 @@ func (s *sender) maybeSendSegment(seg *segment, limit int, end seqnum.Value) (se // triggering bugs in poorly written DNS // implementations. var nextTooBig bool - for seg.Next() != nil && seg.Next().data.Size() != 0 { - if seg.data.Size()+seg.Next().data.Size() > available { + for nSeg := seg.Next(); nSeg != nil && nSeg.data.Size() != 0; nSeg = seg.Next() { + if seg.data.Size()+nSeg.data.Size() > available { nextTooBig = true break } - seg.data.Append(seg.Next().data) - - // Consume the segment that we just merged in. - s.writeList.Remove(seg.Next()) + seg.merge(nSeg) + s.writeList.Remove(nSeg) + nSeg.decRef() } if !nextTooBig && seg.data.Size() < available { // Segment is not full. |