From db01cc62e0aea08dbaba3571fb04d71ce18a8e22 Mon Sep 17 00:00:00 2001
From: Kevin Liang <kevinliang@tailscale.com>
Date: Tue, 19 Mar 2024 20:45:06 +0000
Subject: [PATCH] add the ability to remove routes associated with domain

---
 appc/appconnector.go  | 17 +++++++++++++++++
 ipn/ipnlocal/local.go |  2 ++
 ipn/prefs.go          |  4 ++--
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/appc/appconnector.go b/appc/appconnector.go
index cb11eeafe..dcc56d989 100644
--- a/appc/appconnector.go
+++ b/appc/appconnector.go
@@ -111,6 +111,10 @@ func (e *AppConnector) updateDomains(domains []string) {
 	defer e.mu.Unlock()
 
 	var oldDomains map[string][]netip.Addr
+	var oldDiscovered map[string]ipn.DatedRoute
+	routeInfo := e.routeAdvertiser.ReadRouteInfoFromStore()
+
+	oldDiscovered, routeInfo.Discovered = routeInfo.Discovered, make(map[string]ipn.DatedRoute, len(domains))
 	oldDomains, e.domains = e.domains, make(map[string][]netip.Addr, len(domains))
 	e.wildcards = e.wildcards[:0]
 	for _, d := range domains {
@@ -123,7 +127,9 @@ func (e *AppConnector) updateDomains(domains []string) {
 			continue
 		}
 		e.domains[d] = oldDomains[d]
+		routeInfo.Discovered[d] = oldDiscovered[d]
 		delete(oldDomains, d)
+		delete(oldDiscovered, d)
 	}
 
 	// Ensure that still-live wildcards addresses are preserved as well.
@@ -135,6 +141,17 @@ func (e *AppConnector) updateDomains(domains []string) {
 			}
 		}
 	}
+
+	for d, dr := range oldDiscovered {
+		for _, wc := range e.wildcards {
+			if dnsname.HasSuffix(d, wc) {
+				routeInfo.Discovered[d] = dr
+				break
+			}
+		}
+	}
+
+	e.routeAdvertiser.UpdateRoutesInfoToStore(routeInfo)
 	e.logf("handling domains: %v and wildcards: %v", xmaps.Keys(e.domains), e.wildcards)
 }
 
diff --git a/ipn/ipnlocal/local.go b/ipn/ipnlocal/local.go
index b3fc22cae..8c18ec054 100644
--- a/ipn/ipnlocal/local.go
+++ b/ipn/ipnlocal/local.go
@@ -3562,6 +3562,8 @@ func (b *LocalBackend) reconfigAppConnectorLocked(nm *netmap.NetworkMap, prefs i
 	slices.SortFunc(routes, func(i, j netip.Prefix) int { return i.Addr().Compare(j.Addr()) })
 	domains = slices.Compact(domains)
 	routes = slices.Compact(routes)
+	fmt.Println("Connector Kevin: ", domains)
+	fmt.Println("Connector Kevin: ", routes)
 	b.appConnector.UpdateDomainsAndRoutes(domains, routes)
 }
 
diff --git a/ipn/prefs.go b/ipn/prefs.go
index 3a8566617..8bd667121 100644
--- a/ipn/prefs.go
+++ b/ipn/prefs.go
@@ -962,8 +962,8 @@ type RouteInfo struct {
 
 func (r RouteInfo) UpdateRoutesInDiscoveredForDomain(domain string, addrs []netip.Prefix) {
 	newDatedRoutes := make(DatedRoute)
-	_, hasKey := r.Discovered[domain]
-	if !hasKey {
+	val, hasKey := r.Discovered[domain]
+	if !hasKey || val == nil {
 		r.Discovered[domain] = addAddrsToDatedRoute(newDatedRoutes, addrs)
 		return
 	}