Pull request 1729: upd-go

Merge in DNS/adguard-home from upd-go to master

Squashed commit of the following:

commit 0e13d6863a3d463289823a27414b427cb76be88c
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Feb 7 20:20:14 2023 +0300

    scripts: try increasing test timeout

commit 8e7d230e40de8f49a2b74a6d32a7fc78a361edab
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Feb 7 20:00:17 2023 +0300

    all: upd quic-go; imp atomic values

commit fae2b75b6990f2bd77e5c019a35a72322bac85f7
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Feb 7 17:36:33 2023 +0300

    all: upd go, deps; imp atomic values

internal/home/rdns.go

@@ -16,10 +16,6 @@ type RDNS struct {
 	exchanger dnsforward.RDNSExchanger
 	clients   *clientsContainer
 
-	// usePrivate is used to store the state of current private RDNS resolving
-	// settings and to react to it's changes.
-	usePrivate uint32
-
 	// ipCh used to pass client's IP to rDNS workerLoop.
 	ipCh chan netip.Addr
 
@@ -28,6 +24,10 @@ type RDNS struct {
 	// address will be resolved once again.  If the address couldn't be
 	// resolved, cache prevents further attempts to resolve it for some time.
 	ipCache cache.Cache
+
+	// usePrivate stores the state of current private reverse-DNS resolving
+	// settings.
+	usePrivate atomic.Bool
 }
 
 // Default rDNS values.
@@ -52,9 +52,8 @@ func NewRDNS(
 		}),
 		ipCh: make(chan netip.Addr, defaultRDNSIPChSize),
 	}
-	if usePrivate {
-		rDNS.usePrivate = 1
-	}
+
+	rDNS.usePrivate.Store(usePrivate)
 
 	go rDNS.workerLoop()
 
@@ -68,12 +67,8 @@ func NewRDNS(
 // approach since only unresolved locally-served addresses should be removed.
 // Implement when improving the cache.
 func (r *RDNS) ensurePrivateCache() {
-	var usePrivate uint32
-	if r.exchanger.ResolvesPrivatePTR() {
-		usePrivate = 1
-	}
-
-	if atomic.CompareAndSwapUint32(&r.usePrivate, 1-usePrivate, usePrivate) {
+	usePrivate := r.exchanger.ResolvesPrivatePTR()
+	if r.usePrivate.CompareAndSwap(!usePrivate, usePrivate) {
 		r.ipCache.Clear()
 	}
 }