all: sync with master, upd chlog

internal/dnsforward/clientscontainer.go

@@ -0,0 +1,46 @@
+package dnsforward
+
+import (
+	"net/netip"
+
+	"github.com/AdguardTeam/AdGuardHome/internal/client"
+	"github.com/AdguardTeam/dnsproxy/proxy"
+)
+
+// ClientsContainer provides information about preconfigured DNS clients.
+type ClientsContainer interface {
+	// CustomUpstreamConfig returns the custom client upstream configuration, if
+	// any.  It prioritizes ClientID over client IP address to identify the
+	// client.
+	CustomUpstreamConfig(clientID string, cliAddr netip.Addr) (conf *proxy.CustomUpstreamConfig)
+
+	// UpdateCommonUpstreamConfig updates the common upstream configuration.
+	UpdateCommonUpstreamConfig(conf *client.CommonUpstreamConfig)
+
+	// ClearUpstreamCache clears the upstream cache for each stored custom
+	// client upstream configuration.
+	ClearUpstreamCache()
+}
+
+// EmptyClientsContainer is an [ClientsContainer] implementation that does nothing.
+type EmptyClientsContainer struct{}
+
+// type check
+var _ ClientsContainer = EmptyClientsContainer{}
+
+// CustomUpstreamConfig implements the [ClientsContainer] interface for
+// EmptyClientsContainer.
+func (EmptyClientsContainer) CustomUpstreamConfig(
+	clientID string,
+	cliAddr netip.Addr,
+) (conf *proxy.CustomUpstreamConfig) {
+	return nil
+}
+
+// UpdateCommonUpstreamConfig implements the [ClientsContainer] interface for
+// EmptyClientsContainer.
+func (EmptyClientsContainer) UpdateCommonUpstreamConfig(conf *client.CommonUpstreamConfig) {}
+
+// ClearUpstreamCache implements the [ClientsContainer] interface for
+// EmptyClientsContainer.
+func (EmptyClientsContainer) ClearUpstreamCache() {}