all: imp code, docs

internal/aghtest/upstream.go

@@ -71,7 +71,7 @@ func RespondTo(t testing.TB, req *dns.Msg, cl, qt uint16, targ, answer string) (
 	return resp
 }
 
-// Exchange implements the upstream.Upstream interface for *Upstream.
+// Exchange implements the [upstream.Upstream] interface for *Upstream.
 //
 // TODO(a.garipov): Split further into handlers.
 func (u *Upstream) Exchange(m *dns.Msg) (resp *dns.Msg, err error) {
@@ -117,11 +117,12 @@ func (u *Upstream) Exchange(m *dns.Msg) (resp *dns.Msg, err error) {
 	return resp, nil
 }
 
-// Address implements upstream.Upstream interface for *Upstream.
+// Address implements [upstream.Upstream] interface for *Upstream.
 func (u *Upstream) Address() string {
 	return u.Addr
 }
 
+// Close implements [upstream.Upstream] interface for *Upstream.
 func (u *Upstream) Close() (err error) {
 	return nil
 }

internal/home/clients.go

@@ -21,6 +21,8 @@ import (
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/AdguardTeam/golibs/netutil"
 	"github.com/AdguardTeam/golibs/stringutil"
+	"golang.org/x/exp/maps"
+	"golang.org/x/exp/slices"
 )
 
 const clientsUpdatePeriod = 10 * time.Minute
@@ -50,6 +52,18 @@ type Client struct {
 	UseOwnBlockedServices bool
 }
 
+// closeUpstreams closes the client-specific upstream config of c if any.
+func (c *Client) closeUpstreams() (err error) {
+	if c.upstreamConfig != nil {
+		err = c.upstreamConfig.Close()
+		if err != nil {
+			return fmt.Errorf("closing upstreams of client %q: %w", c.Name, err)
+		}
+	}
+
+	return nil
+}
+
 type clientSource uint
 
 // Client sources.  The order determines the priority.
@@ -651,6 +665,10 @@ func (clients *clientsContainer) Del(name string) (ok bool) {
 		return false
 	}
 
+	if err := c.closeUpstreams(); err != nil {
+		log.Error("client container: removing client %s: %s", name, err)
+	}
+
 	// update Name index
 	delete(clients.list, name)
 
@@ -910,3 +928,23 @@ func (clients *clientsContainer) updateFromDHCP(add bool) {
 
 	log.Debug("clients: added %d client aliases from dhcp", n)
 }
+
+// Close implements the [io.Closer] interface for *clientsContainer.
+func (clients *clientsContainer) Close() (err error) {
+	persistent := maps.Values(clients.list)
+	slices.SortFunc(persistent, func(a, b *Client) bool { return a.Name < b.Name })
+
+	var errs []error
+
+	for _, cli := range persistent {
+		if err = cli.closeUpstreams(); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	if len(errs) > 0 {
+		return errors.List("closing client specific upstreams", errs...)
+	}
+
+	return nil
+}

internal/home/dns.go

@@ -431,17 +431,23 @@ func reconfigureDNSServer() (err error) {
 	return nil
 }
 
-func stopDNSServer() error {
+func stopDNSServer() (err error) {
 	if !isRunning() {
 		return nil
 	}
 
-	err := Context.dnsServer.Stop()
+	err = Context.dnsServer.Stop()
 	if err != nil {
-		return fmt.Errorf("couldn't stop forwarding DNS server: %w", err)
+		return fmt.Errorf("stopping forwarding dns server: %w", err)
+	}
+
+	err = Context.clients.Close()
+	if err != nil {
+		return fmt.Errorf("closing clients container: %w", err)
 	}
 
 	closeDNSServer()
+
 	return nil
 }
 

internal/home/home.go

@@ -122,7 +122,6 @@ func Main(clientBuildFS fs.FS) {
 			case syscall.SIGHUP:
 				Context.clients.Reload()
 				Context.tls.reload()
-
 			default:
 				cleanup(context.Background())
 				cleanupAlways()