Pull request: 2875 fix client filtering settings

Merge in DNS/adguard-home from 2875-client-filtering to master

Updates #2875.

Squashed commit of the following:

commit b3b9582b7dde826005ba79d499ed7e82af067e93
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon May 24 14:22:29 2021 +0300

    all: use atomic, log changes

commit 9304d8b96d0d064d7741c85165ab885f5547fd4c
Author: Eugene Burkov <e.burkov@adguard.com>
Date:   Mon May 24 13:43:22 2021 +0300

    all: fix client filtering settings

internal/home/control.go

@@ -134,7 +134,6 @@ func handleStatus(w http.ResponseWriter, _ *http.Request) {
 	}
 
 	var resp statusResponse
-
 	func() {
 		config.RLock()
 		defer config.RUnlock()

internal/home/controlfiltering.go

@@ -351,8 +351,14 @@ func (f *Filtering) handleFilteringConfig(w http.ResponseWriter, r *http.Request
 		return
 	}
 
-	config.DNS.FilteringEnabled = req.Enabled
-	config.DNS.FiltersUpdateIntervalHours = req.Interval
+	func() {
+		config.Lock()
+		defer config.Unlock()
+
+		config.DNS.FilteringEnabled = req.Enabled
+		config.DNS.FiltersUpdateIntervalHours = req.Interval
+	}()
+
 	onConfigModified()
 	enableFilters(true)
 }
@@ -364,7 +370,6 @@ type checkHostRespRule struct {
 
 type checkHostResp struct {
 	Reason string `json:"reason"`
-
 	// FilterID is the ID of the rule's filter list.
 	//
 	// Deprecated: Use Rules[*].FilterListID.

internal/home/dns.go

@@ -307,7 +307,6 @@ func applyAdditionalFiltering(clientAddr net.IP, clientID string, setts *filteri
 
 	setts.ClientName = c.Name
 	setts.ClientTags = c.Tags
-
 	if !c.UseOwnSettings {
 		return
 	}
@@ -319,14 +318,14 @@ func applyAdditionalFiltering(clientAddr net.IP, clientID string, setts *filteri
 }
 
 func startDNSServer() error {
-	config.Lock()
-	defer config.Unlock()
+	config.RLock()
+	defer config.RUnlock()
 
 	if isRunning() {
 		return fmt.Errorf("unable to start forwarding DNS server: Already running")
 	}
 
-	enableFilters(false)
+	enableFiltersLocked(false)
 
 	Context.clients.Start()
 

internal/home/filter.go

@@ -664,6 +664,13 @@ func (filter *filter) Path() string {
 }
 
 func enableFilters(async bool) {
+	config.RLock()
+	defer config.RUnlock()
+
+	enableFiltersLocked(async)
+}
+
+func enableFiltersLocked(async bool) {
 	var whiteFilters []filtering.Filter
 	filters := []filtering.Filter{{
 		Data: []byte(strings.Join(config.UserRules, "\n")),
@@ -693,4 +700,6 @@ func enableFilters(async bool) {
 	if err := Context.dnsFilter.SetFilters(filters, whiteFilters, async); err != nil {
 		log.Debug("enabling filters: %s", err)
 	}
+
+	Context.dnsFilter.SetEnabled(config.DNS.FilteringEnabled)
 }