Honour the link's MaxHeaderLength when forwarding

This change also updates where the IP packet buffer is held in an
outbound tcpip.PacketBuffer from Header to Data. This change removes
unncessary copying of the IP packet buffer when forwarding.

Test: stack_test.TestNICForwarding
PiperOrigin-RevId: 300217972

1 files changed, 4 insertions, 4 deletions

diff --git a/pkg/tcpip/stack/forwarder_test.go b/pkg/tcpip/stack/forwarder_test.go
index 321b7524d..5a04590d5 100644
--- a/pkg/tcpip/stack/forwarder_test.go
+++ b/pkg/tcpip/stack/forwarder_test.go
@@ -473,7 +473,7 @@ func TestForwardingWithFakeResolverPartialTimeout(t *testing.T) {
 		t.Fatal("packet not forwarded")
 	}
 
-	b := p.Pkt.Header.View()
+	b := p.Pkt.Data.First()
 	if b[0] != 3 {
 		t.Fatalf("got b[0] = %d, want = 3", b[0])
 	}
@@ -517,7 +517,7 @@ func TestForwardingWithFakeResolverTwoPackets(t *testing.T) {
 			t.Fatal("packet not forwarded")
 		}
 
-		b := p.Pkt.Header.View()
+		b := p.Pkt.Data.First()
 		if b[0] != 3 {
 			t.Fatalf("got b[0] = %d, want = 3", b[0])
 		}
@@ -564,7 +564,7 @@ func TestForwardingWithFakeResolverManyPackets(t *testing.T) {
 			t.Fatal("packet not forwarded")
 		}
 
-		b := p.Pkt.Header.View()
+		b := p.Pkt.Data.First()
 		if b[0] != 3 {
 			t.Fatalf("got b[0] = %d, want = 3", b[0])
 		}
@@ -619,7 +619,7 @@ func TestForwardingWithFakeResolverManyResolutions(t *testing.T) {
 
 		// The first 5 packets (address 3 to 7) should not be forwarded
 		// because their address resolutions are interrupted.
-		b := p.Pkt.Header.View()
+		b := p.Pkt.Data.First()
 		if b[0] < 8 {
 			t.Fatalf("got b[0] = %d, want b[0] >= 8", b[0])
 		}