Support performing DAD for any address

...as long as the network protocol supports duplicate address detection.

This CL provides the facilities for a netstack integrator to perform
DAD.

DHCP recommends that clients effectively perform DAD before accepting an
offer. As per RFC 2131 section 4.4.1 pg 38,

  The client SHOULD perform a check on the suggested address to ensure
  that the address is not already in use.  For example, if the client
  is on a network that supports ARP, the client may issue an ARP request
  for the suggested request.

The implementation of ARP-based IPv4 DAD effectively operates the same
as IPv6's NDP DAD - using ARP requests and responses in place of
NDP neighbour solicitations and advertisements, respectively.

DAD performed by calls to (*Stack).CheckDuplicateAddress don't interfere
with DAD performed when a new IPv6 address is added. This is so that
integrator requests to check for duplicate addresses aren't unexpectedly
aborted when addresses are removed.

A network package internal package provides protocol agnostic DAD state
management that specific protocols that provide DAD can use.

Fixes #4550.

Tests:
  - internal/ip_test.*
  - integration_test.TestDAD
  - arp_test.TestDADARPRequestPacket
  - ipv6.TestCheckDuplicateAddress
PiperOrigin-RevId: 356405593

1 files changed, 5 insertions, 5 deletions

diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go
index 62066b3aa..92a0cb401 100644
--- a/pkg/tcpip/stack/stack_test.go
+++ b/pkg/tcpip/stack/stack_test.go
@@ -2573,16 +2573,16 @@ func TestNICAutoGenAddrDoesDAD(t *testing.T) {
 	ndpDisp := ndpDispatcher{
 		dadC: make(chan ndpDADEvent),
 	}
-	ndpConfigs := ipv6.DefaultNDPConfigurations()
+	dadConfigs := stack.DefaultDADConfigurations()
 	opts := stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
-			NDPConfigs:       ndpConfigs,
 			AutoGenLinkLocal: true,
 			NDPDisp:          &ndpDisp,
+			DADConfigs:       dadConfigs,
 		})},
 	}
 
-	e := channel.New(int(ndpConfigs.DupAddrDetectTransmits), 1280, linkAddr1)
+	e := channel.New(int(dadConfigs.DupAddrDetectTransmits), 1280, linkAddr1)
 	s := stack.New(opts)
 	if err := s.CreateNIC(nicID, e); err != nil {
 		t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
@@ -2598,7 +2598,7 @@ func TestNICAutoGenAddrDoesDAD(t *testing.T) {
 
 	// Wait for DAD to resolve.
 	select {
-	case <-time.After(time.Duration(ndpConfigs.DupAddrDetectTransmits)*ndpConfigs.RetransmitTimer + time.Second):
+	case <-time.After(time.Duration(dadConfigs.DupAddrDetectTransmits)*dadConfigs.RetransmitTimer + time.Second):
 		// We should get a resolution event after 1s (default time to
 		// resolve as per default NDP configurations). Waiting for that
 		// resolution time + an extra 1s without a resolution event
@@ -3235,7 +3235,7 @@ func TestDoDADWhenNICEnabled(t *testing.T) {
 	}
 	opts := stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
-			NDPConfigs: ipv6.NDPConfigurations{
+			DADConfigs: stack.DADConfigurations{
 				DupAddrDetectTransmits: dadTransmits,
 				RetransmitTimer:        retransmitTimer,
 			},