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-rw-r--r--pkg/tcpip/header/BUILD7
-rw-r--r--pkg/tcpip/header/checksum.go133
-rw-r--r--pkg/tcpip/header/checksum_test.go62
-rw-r--r--pkg/tcpip/header/ipv6.go7
-rw-r--r--pkg/tcpip/header/ndp_router_solicit.go36
5 files changed, 238 insertions, 7 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD
index f2061c778..9da0d71f8 100644
--- a/pkg/tcpip/header/BUILD
+++ b/pkg/tcpip/header/BUILD
@@ -1,5 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_test")
-load("//tools/go_stateify:defs.bzl", "go_library")
+load("//tools:defs.bzl", "go_library", "go_test")
package(licenses = ["notice"])
@@ -20,10 +19,10 @@ go_library(
"ndp_neighbor_solicit.go",
"ndp_options.go",
"ndp_router_advert.go",
+ "ndp_router_solicit.go",
"tcp.go",
"udp.go",
],
- importpath = "gvisor.dev/gvisor/pkg/tcpip/header",
visibility = ["//visibility:public"],
deps = [
"//pkg/tcpip",
@@ -58,7 +57,7 @@ go_test(
"eth_test.go",
"ndp_test.go",
],
- embed = [":header"],
+ library = ":header",
deps = [
"//pkg/tcpip",
"@com_github_google_go-cmp//cmp:go_default_library",
diff --git a/pkg/tcpip/header/checksum.go b/pkg/tcpip/header/checksum.go
index 9749c7f4d..14a4b2b44 100644
--- a/pkg/tcpip/header/checksum.go
+++ b/pkg/tcpip/header/checksum.go
@@ -45,12 +45,139 @@ func calculateChecksum(buf []byte, odd bool, initial uint32) (uint16, bool) {
return ChecksumCombine(uint16(v), uint16(v>>16)), odd
}
+func unrolledCalculateChecksum(buf []byte, odd bool, initial uint32) (uint16, bool) {
+ v := initial
+
+ if odd {
+ v += uint32(buf[0])
+ buf = buf[1:]
+ }
+
+ l := len(buf)
+ odd = l&1 != 0
+ if odd {
+ l--
+ v += uint32(buf[l]) << 8
+ }
+ for (l - 64) >= 0 {
+ i := 0
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ i += 16
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ i += 16
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ i += 16
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ buf = buf[64:]
+ l = l - 64
+ }
+ if (l - 32) >= 0 {
+ i := 0
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ i += 16
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ buf = buf[32:]
+ l = l - 32
+ }
+ if (l - 16) >= 0 {
+ i := 0
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9])
+ v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11])
+ v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13])
+ v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15])
+ buf = buf[16:]
+ l = l - 16
+ }
+ if (l - 8) >= 0 {
+ i := 0
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5])
+ v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7])
+ buf = buf[8:]
+ l = l - 8
+ }
+ if (l - 4) >= 0 {
+ i := 0
+ v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
+ v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3])
+ buf = buf[4:]
+ l = l - 4
+ }
+
+ // At this point since l was even before we started unrolling
+ // there can be only two bytes left to add.
+ if l != 0 {
+ v += (uint32(buf[0]) << 8) + uint32(buf[1])
+ }
+
+ return ChecksumCombine(uint16(v), uint16(v>>16)), odd
+}
+
+// ChecksumOld calculates the checksum (as defined in RFC 1071) of the bytes in
+// the given byte array. This function uses a non-optimized implementation. Its
+// only retained for reference and to use as a benchmark/test. Most code should
+// use the header.Checksum function.
+//
+// The initial checksum must have been computed on an even number of bytes.
+func ChecksumOld(buf []byte, initial uint16) uint16 {
+ s, _ := calculateChecksum(buf, false, uint32(initial))
+ return s
+}
+
// Checksum calculates the checksum (as defined in RFC 1071) of the bytes in the
-// given byte array.
+// given byte array. This function uses an optimized unrolled version of the
+// checksum algorithm.
//
// The initial checksum must have been computed on an even number of bytes.
func Checksum(buf []byte, initial uint16) uint16 {
- s, _ := calculateChecksum(buf, false, uint32(initial))
+ s, _ := unrolledCalculateChecksum(buf, false, uint32(initial))
return s
}
@@ -86,7 +213,7 @@ func ChecksumVVWithOffset(vv buffer.VectorisedView, initial uint16, off int, siz
}
v = v[:l]
- sum, odd = calculateChecksum(v, odd, uint32(sum))
+ sum, odd = unrolledCalculateChecksum(v, odd, uint32(sum))
size -= len(v)
if size == 0 {
diff --git a/pkg/tcpip/header/checksum_test.go b/pkg/tcpip/header/checksum_test.go
index 86b466c1c..309403482 100644
--- a/pkg/tcpip/header/checksum_test.go
+++ b/pkg/tcpip/header/checksum_test.go
@@ -17,6 +17,8 @@
package header_test
import (
+ "fmt"
+ "math/rand"
"testing"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
@@ -107,3 +109,63 @@ func TestChecksumVVWithOffset(t *testing.T) {
})
}
}
+
+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)
+ }
+ })
+ }
+ }
+}
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index 83425c614..70e6ce095 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -84,6 +84,13 @@ const (
// The address is ff02::1.
IPv6AllNodesMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"
+ // IPv6AllRoutersMulticastAddress is a link-local multicast group that
+ // all IPv6 routers MUST join, as per RFC 4291, section 2.8. Packets
+ // destined to this address will reach all routers on a link.
+ //
+ // The address is ff02::2.
+ IPv6AllRoutersMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02"
+
// IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460,
// section 5.
IPv6MinimumMTU = 1280
diff --git a/pkg/tcpip/header/ndp_router_solicit.go b/pkg/tcpip/header/ndp_router_solicit.go
new file mode 100644
index 000000000..9e67ba95d
--- /dev/null
+++ b/pkg/tcpip/header/ndp_router_solicit.go
@@ -0,0 +1,36 @@
+// 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
+
+// NDPRouterSolicit is an NDP Router Solicitation message. It will only contain
+// the body of an ICMPv6 packet.
+//
+// See RFC 4861 section 4.1 for more details.
+type NDPRouterSolicit []byte
+
+const (
+ // NDPRSMinimumSize is the minimum size of a valid NDP Router
+ // Solicitation message (body of an ICMPv6 packet).
+ NDPRSMinimumSize = 4
+
+ // ndpRSOptionsOffset is the start of the NDP options in an
+ // NDPRouterSolicit.
+ ndpRSOptionsOffset = 4
+)
+
+// Options returns an NDPOptions of the the options body.
+func (b NDPRouterSolicit) Options() NDPOptions {
+ return NDPOptions(b[ndpRSOptionsOffset:])
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-24 12:24:06 +0000