mapper: compare peer routes against node

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

hscontrol/mapper/mapper.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/fs"
+	"net/netip"
 	"net/url"
 	"os"
 	"path"
@@ -308,9 +309,15 @@ func (m *Mapper) PeerChangedResponse(
 		resp.PeersChangedPatch = patches
 	}
 
+	_, matchers := m.polMan.Filter()
 	// Add the node itself, it might have changed, and particularly
 	// if there are no patches or changes, this is a self update.
-	tailnode, err := tailNode(node, mapRequest.Version, m.polMan, m.primary, m.cfg)
+	tailnode, err := tailNode(
+		node, mapRequest.Version, m.polMan,
+		func(id types.NodeID) []netip.Prefix {
+			return policy.ReduceRoutes(node, m.primary.PrimaryRoutes(id), matchers)
+		},
+		m.cfg)
 	if err != nil {
 		return nil, err
 	}
@@ -347,7 +354,7 @@ func (m *Mapper) marshalMapResponse(
 	}
 
 	if debugDumpMapResponsePath != "" {
-		data := map[string]interface{}{
+		data := map[string]any{
 			"Messages":    messages,
 			"MapRequest":  mapRequest,
 			"MapResponse": resp,
@@ -457,7 +464,13 @@ func (m *Mapper) baseWithConfigMapResponse(
 ) (*tailcfg.MapResponse, error) {
 	resp := m.baseMapResponse()
 
-	tailnode, err := tailNode(node, capVer, m.polMan, m.primary, m.cfg)
+	_, matchers := m.polMan.Filter()
+	tailnode, err := tailNode(
+		node, capVer, m.polMan,
+		func(id types.NodeID) []netip.Prefix {
+			return policy.ReduceRoutes(node, m.primary.PrimaryRoutes(id), matchers)
+		},
+		m.cfg)
 	if err != nil {
 		return nil, err
 	}
@@ -513,15 +526,10 @@ func (m *Mapper) ListNodes(nodeIDs ...types.NodeID) (types.Nodes, error) {
 	return nodes, nil
 }
 
-func nodeMapToList(nodes map[uint64]*types.Node) types.Nodes {
-	ret := make(types.Nodes, 0)
-
-	for _, node := range nodes {
-		ret = append(ret, node)
-	}
-
-	return ret
-}
+// routeFilterFunc is a function that takes a node ID and returns a list of
+// netip.Prefixes that are allowed for that node. It is used to filter routes
+// from the primary route manager to the node.
+type routeFilterFunc func(id types.NodeID) []netip.Prefix
 
 // appendPeerChanges mutates a tailcfg.MapResponse with all the
 // necessary changes when peers have changed.
@@ -553,7 +561,12 @@ func appendPeerChanges(
 
 	dnsConfig := generateDNSConfig(cfg, node)
 
-	tailPeers, err := tailNodes(changed, capVer, polMan, primary, cfg)
+	tailPeers, err := tailNodes(
+		changed, capVer, polMan,
+		func(id types.NodeID) []netip.Prefix {
+			return policy.ReduceRoutes(node, primary.PrimaryRoutes(id), matchers)
+		},
+		cfg)
 	if err != nil {
 		return err
 	}

hscontrol/mapper/tail.go

@@ -5,7 +5,6 @@ import (
 	"time"
 
 	"github.com/juanfont/headscale/hscontrol/policy"
-	"github.com/juanfont/headscale/hscontrol/routes"
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/samber/lo"
 	"tailscale.com/net/tsaddr"
@@ -16,7 +15,7 @@ func tailNodes(
 	nodes types.Nodes,
 	capVer tailcfg.CapabilityVersion,
 	polMan policy.PolicyManager,
-	primary *routes.PrimaryRoutes,
+	primaryRouteFunc routeFilterFunc,
 	cfg *types.Config,
 ) ([]*tailcfg.Node, error) {
 	tNodes := make([]*tailcfg.Node, len(nodes))
@@ -26,7 +25,7 @@ func tailNodes(
 			node,
 			capVer,
 			polMan,
-			primary,
+			primaryRouteFunc,
 			cfg,
 		)
 		if err != nil {
@@ -44,7 +43,7 @@ func tailNode(
 	node *types.Node,
 	capVer tailcfg.CapabilityVersion,
 	polMan policy.PolicyManager,
-	primary *routes.PrimaryRoutes,
+	primaryRouteFunc routeFilterFunc,
 	cfg *types.Config,
 ) (*tailcfg.Node, error) {
 	addrs := node.Prefixes()
@@ -81,8 +80,7 @@ func tailNode(
 	}
 	tags = lo.Uniq(append(tags, node.ForcedTags...))
 
-	_, matchers := polMan.Filter()
-	routes := policy.ReduceRoutes(node, primary.PrimaryRoutes(node.ID), matchers)
+	routes := primaryRouteFunc(node.ID)
 	allowed := append(node.Prefixes(), routes...)
 	allowed = append(allowed, node.ExitRoutes()...)
 	tsaddr.SortPrefixes(allowed)
@@ -101,7 +99,7 @@ func tailNode(
 		Machine:          node.MachineKey,
 		DiscoKey:         node.DiscoKey,
 		Addresses:        addrs,
-		PrimaryRoutes:    primary.PrimaryRoutes(node.ID),
+		PrimaryRoutes:    routes,
 		AllowedIPs:       allowed,
 		Endpoints:        node.Endpoints,
 		HomeDERP:         derp,

hscontrol/mapper/tail_test.go

@@ -219,7 +219,9 @@ func TestTailNode(t *testing.T) {
 				tt.node,
 				0,
 				polMan,
-				primary,
+				func(id types.NodeID) []netip.Prefix {
+					return primary.PrimaryRoutes(id)
+				},
 				cfg,
 			)
 
@@ -266,6 +268,7 @@ func TestNodeExpiry(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			node := &types.Node{
+				ID:        0,
 				GivenName: "test",
 				Expiry:    tt.exp,
 			}
@@ -276,7 +279,9 @@ func TestNodeExpiry(t *testing.T) {
 				node,
 				0,
 				polMan,
-				nil,
+				func(id types.NodeID) []netip.Prefix {
+					return []netip.Prefix{}
+				},
 				&types.Config{},
 			)
 			if err != nil {