Refactor SLAAC address state into SLAAC prefix state

Previously, SLAAC related state was stored on a per-address basis. This was
sufficient for the simple case of a single SLAAC address per prefix, but
future CLs will introduce temporary addresses which will result in multiple
SLAAC addresses for a prefix. This refactor allows storing multiple addresses
for a prefix in a single SLAAC prefix state.

No behaviour changes - existing tests continue to pass.

PiperOrigin-RevId: 300832812

1 files changed, 11 insertions, 9 deletions

diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 11eaa6a2c..9dcb1d52c 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -126,12 +126,12 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC
 	nic.mu.mcastJoins = make(map[NetworkEndpointID]uint32)
 	nic.mu.packetEPs = make(map[tcpip.NetworkProtocolNumber][]PacketEndpoint)
 	nic.mu.ndp = ndpState{
-		nic:              nic,
-		configs:          stack.ndpConfigs,
-		dad:              make(map[tcpip.Address]dadState),
-		defaultRouters:   make(map[tcpip.Address]defaultRouterState),
-		onLinkPrefixes:   make(map[tcpip.Subnet]onLinkPrefixState),
-		autoGenAddresses: make(map[tcpip.Address]autoGenAddressState),
+		nic:            nic,
+		configs:        stack.ndpConfigs,
+		dad:            make(map[tcpip.Address]dadState),
+		defaultRouters: make(map[tcpip.Address]defaultRouterState),
+		onLinkPrefixes: make(map[tcpip.Subnet]onLinkPrefixState),
+		slaacPrefixes:  make(map[tcpip.Subnet]slaacPrefixState),
 	}
 
 	// Register supported packet endpoint protocols.
@@ -1017,8 +1017,7 @@ func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error {
 	isIPv6Unicast := r.protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(addr)
 
 	if isIPv6Unicast {
-		// If we are removing a tentative IPv6 unicast address, stop
-		// DAD.
+		// If we are removing a tentative IPv6 unicast address, stop DAD.
 		if kind == permanentTentative {
 			n.mu.ndp.stopDuplicateAddressDetection(addr)
 		}
@@ -1026,7 +1025,10 @@ func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error {
 		// If we are removing an address generated via SLAAC, cleanup
 		// its SLAAC resources and notify the integrator.
 		if r.configType == slaac {
-			n.mu.ndp.cleanupAutoGenAddrResourcesAndNotify(addr)
+			n.mu.ndp.cleanupSLAACAddrResourcesAndNotify(tcpip.AddressWithPrefix{
+				Address:   addr,
+				PrefixLen: r.ep.PrefixLen(),
+			})
 		}
 	}