| // Copyright 2019 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 header provides the implementation of the encoding and decoding of |
| // network protocol headers. |
| package header_test |
| |
| import ( |
| "bytes" |
| "fmt" |
| "math/rand" |
| "sync" |
| "testing" |
| |
| "gvisor.dev/gvisor/pkg/tcpip/buffer" |
| "gvisor.dev/gvisor/pkg/tcpip/header" |
| ) |
| |
| func TestChecksumer(t *testing.T) { |
| testCases := []struct { |
| name string |
| data [][]byte |
| want uint16 |
| }{ |
| { |
| name: "empty", |
| want: 0, |
| }, |
| { |
| name: "OneOddView", |
| data: [][]byte{ |
| []byte{1, 9, 0, 5, 4}, |
| }, |
| want: 1294, |
| }, |
| { |
| name: "TwoOddViews", |
| data: [][]byte{ |
| []byte{1, 9, 0, 5, 4}, |
| []byte{4, 3, 7, 1, 2, 123}, |
| }, |
| want: 33819, |
| }, |
| { |
| name: "OneEvenView", |
| data: [][]byte{ |
| []byte{1, 9, 0, 5}, |
| }, |
| want: 270, |
| }, |
| { |
| name: "TwoEvenViews", |
| data: [][]byte{ |
| buffer.NewViewFromBytes([]byte{98, 1, 9, 0}), |
| buffer.NewViewFromBytes([]byte{9, 0, 5, 4}), |
| }, |
| want: 30981, |
| }, |
| { |
| name: "ThreeViews", |
| data: [][]byte{ |
| []byte{77, 11, 33, 0, 55, 44}, |
| []byte{98, 1, 9, 0, 5, 4}, |
| []byte{4, 3, 7, 1, 2, 123, 99}, |
| }, |
| want: 34236, |
| }, |
| } |
| for _, tc := range testCases { |
| t.Run(tc.name, func(t *testing.T) { |
| var all bytes.Buffer |
| var c header.Checksumer |
| for _, b := range tc.data { |
| c.Add(b) |
| // Append to the buffer. We will check the checksum as a whole later. |
| if _, err := all.Write(b); err != nil { |
| t.Fatalf("all.Write(b) = _, %s; want _, nil", err) |
| } |
| } |
| if got, want := c.Checksum(), tc.want; got != want { |
| t.Errorf("c.Checksum() = %d, want %d", got, want) |
| } |
| if got, want := header.Checksum(all.Bytes(), 0 /* initial */), tc.want; got != want { |
| t.Errorf("Checksum(flatten tc.data) = %d, want %d", got, want) |
| } |
| }) |
| } |
| } |
| |
| func TestChecksum(t *testing.T) { |
| var bufSizes = []int{0, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128, 255, 256, 257, 1023, 1024} |
| type testCase struct { |
| buf []byte |
| initial uint16 |
| csumOrig uint16 |
| csumNew uint16 |
| } |
| testCases := make([]testCase, 100000) |
| // Ensure same buffer generation for test consistency. |
| rnd := rand.New(rand.NewSource(42)) |
| for i := range testCases { |
| testCases[i].buf = make([]byte, bufSizes[i%len(bufSizes)]) |
| testCases[i].initial = uint16(rnd.Intn(65536)) |
| rnd.Read(testCases[i].buf) |
| } |
| |
| for i := range testCases { |
| testCases[i].csumOrig = header.ChecksumOld(testCases[i].buf, testCases[i].initial) |
| testCases[i].csumNew = header.Checksum(testCases[i].buf, testCases[i].initial) |
| if got, want := testCases[i].csumNew, testCases[i].csumOrig; got != want { |
| t.Fatalf("new checksum for (buf = %x, initial = %d) does not match old got: %d, want: %d", testCases[i].buf, testCases[i].initial, got, want) |
| } |
| } |
| } |
| |
| func BenchmarkChecksum(b *testing.B) { |
| var bufSizes = []int{64, 128, 256, 512, 1024, 1500, 2048, 4096, 8192, 16384, 32767, 32768, 65535, 65536} |
| |
| checkSumImpls := []struct { |
| fn func([]byte, uint16) uint16 |
| name string |
| }{ |
| {header.ChecksumOld, fmt.Sprintf("checksum_old")}, |
| {header.Checksum, fmt.Sprintf("checksum")}, |
| } |
| |
| for _, csumImpl := range checkSumImpls { |
| // Ensure same buffer generation for test consistency. |
| rnd := rand.New(rand.NewSource(42)) |
| for _, bufSz := range bufSizes { |
| b.Run(fmt.Sprintf("%s_%d", csumImpl.name, bufSz), func(b *testing.B) { |
| tc := struct { |
| buf []byte |
| initial uint16 |
| csum uint16 |
| }{ |
| buf: make([]byte, bufSz), |
| initial: uint16(rnd.Intn(65536)), |
| } |
| rnd.Read(tc.buf) |
| b.ResetTimer() |
| for i := 0; i < b.N; i++ { |
| tc.csum = csumImpl.fn(tc.buf, tc.initial) |
| } |
| }) |
| } |
| } |
| } |
| |
| func testICMPChecksum(t *testing.T, headerChecksum func() uint16, icmpChecksum func() uint16, want uint16, pktStr string) { |
| // icmpChecksum should not do any modifications of the header to |
| // calculate its checksum. Let's call it from a few go-routines and the |
| // race detector will trigger a warning if there are any concurrent |
| // read/write accesses. |
| |
| const concurrency = 5 |
| start := make(chan int) |
| ready := make(chan bool, concurrency) |
| var wg sync.WaitGroup |
| wg.Add(concurrency) |
| defer wg.Wait() |
| |
| for i := 0; i < concurrency; i++ { |
| go func() { |
| defer wg.Done() |
| |
| ready <- true |
| <-start |
| |
| if got := headerChecksum(); want != got { |
| t.Errorf("new checksum for %s does not match old got: %x, want: %x", pktStr, got, want) |
| } |
| if got := icmpChecksum(); want != got { |
| t.Errorf("new checksum for %s does not match old got: %x, want: %x", pktStr, got, want) |
| } |
| }() |
| } |
| for i := 0; i < concurrency; i++ { |
| <-ready |
| } |
| close(start) |
| } |
| |
| func TestICMPv4Checksum(t *testing.T) { |
| rnd := rand.New(rand.NewSource(42)) |
| |
| h := header.ICMPv4(make([]byte, header.ICMPv4MinimumSize)) |
| if _, err := rnd.Read(h); err != nil { |
| t.Fatalf("rnd.Read failed: %v", err) |
| } |
| h.SetChecksum(0) |
| |
| buf := make([]byte, 13) |
| if _, err := rnd.Read(buf); err != nil { |
| t.Fatalf("rnd.Read failed: %v", err) |
| } |
| vv := buffer.NewVectorisedView(len(buf), []buffer.View{ |
| buffer.NewViewFromBytes(buf[:5]), |
| buffer.NewViewFromBytes(buf[5:]), |
| }) |
| |
| want := header.Checksum(vv.ToView(), 0) |
| want = ^header.Checksum(h, want) |
| h.SetChecksum(want) |
| |
| testICMPChecksum(t, h.Checksum, func() uint16 { |
| return header.ICMPv4Checksum(h, header.ChecksumVV(vv, 0)) |
| }, want, fmt.Sprintf("header: {% x} data {% x}", h, vv.ToView())) |
| } |
| |
| func TestICMPv6Checksum(t *testing.T) { |
| rnd := rand.New(rand.NewSource(42)) |
| |
| h := header.ICMPv6(make([]byte, header.ICMPv6MinimumSize)) |
| if _, err := rnd.Read(h); err != nil { |
| t.Fatalf("rnd.Read failed: %v", err) |
| } |
| h.SetChecksum(0) |
| |
| buf := make([]byte, 13) |
| if _, err := rnd.Read(buf); err != nil { |
| t.Fatalf("rnd.Read failed: %v", err) |
| } |
| vv := buffer.NewVectorisedView(len(buf), []buffer.View{ |
| buffer.NewViewFromBytes(buf[:7]), |
| buffer.NewViewFromBytes(buf[7:10]), |
| buffer.NewViewFromBytes(buf[10:]), |
| }) |
| |
| dst := header.IPv6Loopback |
| src := header.IPv6Loopback |
| |
| want := header.PseudoHeaderChecksum(header.ICMPv6ProtocolNumber, src, dst, uint16(len(h)+vv.Size())) |
| want = header.Checksum(vv.ToView(), want) |
| want = ^header.Checksum(h, want) |
| h.SetChecksum(want) |
| |
| testICMPChecksum(t, h.Checksum, func() uint16 { |
| return header.ICMPv6Checksum(header.ICMPv6ChecksumParams{ |
| Header: h, |
| Src: src, |
| Dst: dst, |
| PayloadCsum: header.ChecksumVV(vv, 0), |
| PayloadLen: vv.Size(), |
| }) |
| }, want, fmt.Sprintf("header: {% x} data {% x}", h, vv.ToView())) |
| } |