x/net/internal/icmp: add ParseIPv4Header
This CL adds ParseIPv4Header for parsing an IPv4 header in ICMP
error message. We cannot use ipv4.ParseHeader for it because they
are different things processed by either ip_input or icmp_input.
LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/184850043
diff --git a/internal/icmp/ipv4_test.go b/internal/icmp/ipv4_test.go
new file mode 100644
index 0000000..b05c697
--- /dev/null
+++ b/internal/icmp/ipv4_test.go
@@ -0,0 +1,71 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package icmp
+
+import (
+ "net"
+ "reflect"
+ "runtime"
+ "testing"
+
+ "golang.org/x/net/ipv4"
+)
+
+var (
+ wireHeaderFromKernel = [ipv4.HeaderLen]byte{
+ 0x45, 0x01, 0xbe, 0xef,
+ 0xca, 0xfe, 0x45, 0xdc,
+ 0xff, 0x01, 0xde, 0xad,
+ 172, 16, 254, 254,
+ 192, 168, 0, 1,
+ }
+ wireHeaderFromTradBSDKernel = [ipv4.HeaderLen]byte{
+ 0x45, 0x01, 0xef, 0xbe,
+ 0xca, 0xfe, 0x45, 0xdc,
+ 0xff, 0x01, 0xde, 0xad,
+ 172, 16, 254, 254,
+ 192, 168, 0, 1,
+ }
+ // TODO(mikio): Add platform dependent wire header formats when
+ // we support new platforms.
+
+ testHeader = &ipv4.Header{
+ Version: ipv4.Version,
+ Len: ipv4.HeaderLen,
+ TOS: 1,
+ TotalLen: 0xbeef,
+ ID: 0xcafe,
+ Flags: ipv4.DontFragment,
+ FragOff: 1500,
+ TTL: 255,
+ Protocol: 1,
+ Checksum: 0xdead,
+ Src: net.IPv4(172, 16, 254, 254),
+ Dst: net.IPv4(192, 168, 0, 1),
+ }
+)
+
+func TestParseIPv4Header(t *testing.T) {
+ var wh []byte
+ switch runtime.GOOS {
+ case "darwin":
+ wh = wireHeaderFromTradBSDKernel[:]
+ case "freebsd":
+ if freebsdVersion >= 1000000 {
+ wh = wireHeaderFromKernel[:]
+ } else {
+ wh = wireHeaderFromTradBSDKernel[:]
+ }
+ default:
+ wh = wireHeaderFromKernel[:]
+ }
+ h, err := ParseIPv4Header(wh)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if !reflect.DeepEqual(h, testHeader) {
+ t.Fatalf("got %#v; want %#v", h, testHeader)
+ }
+}
