Bug 1936996 - Use static pref getters instead of observer notification r=necko-reviewers,kershaw

Differential Revision: https://phabricator.services.mozilla.com/D232039

netwerk/dns/GetAddrInfo.cpp

@@ -387,7 +387,7 @@ nsresult GetAddrInfo(const nsACString& aHost, uint16_t aAddressFamily,
     host = aHost;
   }
 
-  if (gNativeIsLocalhost) {
+  if (StaticPrefs::network_dns_native_is_localhost()) {
     // pretend we use the given host but use IPv4 localhost instead!
     host = "localhost"_ns;
     aAddressFamily = PR_AF_INET;

netwerk/dns/nsDNSService2.cpp

@@ -56,10 +56,8 @@ static const char kPrefDnsCacheExpiration[] = "network.dnsCacheExpiration";
 static const char kPrefDnsCacheGrace[] =
     "network.dnsCacheExpirationGracePeriod";
 static const char kPrefIPv4OnlyDomains[] = "network.dns.ipv4OnlyDomains";
-static const char kPrefBlockDotOnion[] = "network.dns.blockDotOnion";
 static const char kPrefDnsLocalDomains[] = "network.dns.localDomains";
 static const char kPrefDnsForceResolve[] = "network.dns.forceResolve";
-static const char kPrefDnsOfflineLocalhost[] = "network.dns.offline-localhost";
 static const char kPrefDnsNotifyResolution[] = "network.dns.notifyResolution";
 static const char kPrefDnsMockHTTPSRRDomain[] =
     "network.dns.mock_HTTPS_RR_domain";
@@ -779,17 +777,6 @@ void nsDNSService::ReadPrefs(const char* name) {
   bool tmpbool;
 
   // DNSservice prefs
-  if (!name || !strcmp(name, kPrefDnsOfflineLocalhost)) {
-    if (NS_SUCCEEDED(
-            Preferences::GetBool(kPrefDnsOfflineLocalhost, &tmpbool))) {
-      mOfflineLocalhost = tmpbool;
-    }
-  }
-  if (!name || !strcmp(name, kPrefBlockDotOnion)) {
-    if (NS_SUCCEEDED(Preferences::GetBool(kPrefBlockDotOnion, &tmpbool))) {
-      mBlockDotOnion = tmpbool;
-    }
-  }
   if (!name || !strcmp(name, kPrefDnsNotifyResolution)) {
     if (NS_SUCCEEDED(
             Preferences::GetBool(kPrefDnsNotifyResolution, &tmpbool))) {
@@ -861,8 +848,6 @@ nsDNSService::Init() {
     prefs->AddObserver(kPrefIPv4OnlyDomains, this, false);
     prefs->AddObserver(kPrefDnsLocalDomains, this, false);
     prefs->AddObserver(kPrefDnsForceResolve, this, false);
-    prefs->AddObserver(kPrefDnsOfflineLocalhost, this, false);
-    prefs->AddObserver(kPrefBlockDotOnion, this, false);
     prefs->AddObserver(kPrefDnsNotifyResolution, this, false);
     prefs->AddObserver(kPrefDnsMockHTTPSRRDomain, this, false);
     AddPrefObserver(prefs);
@@ -940,7 +925,8 @@ nsresult nsDNSService::PreprocessHostname(bool aLocalDomain,
                                           const nsACString& aInput,
                                           nsACString& aACE) {
   // Enforce RFC 7686
-  if (mBlockDotOnion && StringEndsWith(aInput, ".onion"_ns)) {
+  if (StaticPrefs::network_dns_blockDotOnion() &&
+      StringEndsWith(aInput, ".onion"_ns)) {
     return NS_ERROR_UNKNOWN_HOST;
   }
 
@@ -1026,8 +1012,8 @@ nsresult nsDNSService::AsyncResolveInternal(
     return rv;
   }
 
-  if (GetOffline() &&
-      (!mOfflineLocalhost || !hostname.LowerCaseEqualsASCII("localhost"))) {
+  if (GetOffline() && (!StaticPrefs::network_dns_offline_localhost() ||
+                       !hostname.LowerCaseEqualsASCII("localhost"))) {
     flags |= RESOLVE_OFFLINE;
   }
 
@@ -1231,8 +1217,8 @@ nsresult nsDNSService::ResolveInternal(
     return rv;
   }
 
-  if (GetOffline() &&
-      (!mOfflineLocalhost || !hostname.LowerCaseEqualsASCII("localhost"))) {
+  if (GetOffline() && (!StaticPrefs::network_dns_offline_localhost() ||
+                       !hostname.LowerCaseEqualsASCII("localhost"))) {
     flags |= RESOLVE_OFFLINE;
   }
 

netwerk/dns/nsDNSService2.h

@@ -119,9 +119,7 @@ class nsDNSService final : public mozilla::net::DNSServiceBase,
   nsCString mForceResolve;
   nsCString mMockHTTPSRRDomain;
   mozilla::Atomic<bool, mozilla::Relaxed> mHasMockHTTPSRRDomainSet{false};
-  bool mBlockDotOnion = false;
   bool mNotifyResolution = false;
-  bool mOfflineLocalhost = false;
   bool mForceResolveOn = false;
   nsTHashSet<nsCString> mLocalDomains;
   RefPtr<mozilla::net::TRRService> mTrrService;

netwerk/dns/nsHostResolver.cpp

@@ -166,29 +166,8 @@ NS_IMPL_ISUPPORTS(DnsThreadListener, nsIThreadPoolListener)
 
 //----------------------------------------------------------------------------
 
-static const char kPrefGetTtl[] = "network.dns.get-ttl";
-static const char kPrefNativeIsLocalhost[] = "network.dns.native-is-localhost";
-static const char kPrefThreadIdleTime[] =
-    "network.dns.resolver-thread-extra-idle-time-seconds";
-static bool sGetTtlEnabled = false;
-mozilla::Atomic<bool, mozilla::Relaxed> gNativeIsLocalhost;
 mozilla::Atomic<bool, mozilla::Relaxed> sNativeHTTPSSupported{false};
 
-static void DnsPrefChanged(const char* aPref, void* aSelf) {
-  MOZ_ASSERT(NS_IsMainThread(),
-             "Should be getting pref changed notification on main thread!");
-
-  MOZ_ASSERT(aSelf);
-
-  if (!strcmp(aPref, kPrefGetTtl)) {
-#ifdef DNSQUERY_AVAILABLE
-    sGetTtlEnabled = Preferences::GetBool(kPrefGetTtl);
-#endif
-  } else if (!strcmp(aPref, kPrefNativeIsLocalhost)) {
-    gNativeIsLocalhost = Preferences::GetBool(kPrefNativeIsLocalhost);
-  }
-}
-
 NS_IMPL_ISUPPORTS0(nsHostResolver)
 
 nsHostResolver::nsHostResolver()
@@ -212,21 +191,6 @@ nsresult nsHostResolver::Init() MOZ_NO_THREAD_SAFETY_ANALYSIS {
   mShutdown = false;
   mNCS = NetworkConnectivityService::GetSingleton();
 
-  // The preferences probably haven't been loaded from the disk yet, so we
-  // need to register a callback that will set up the experiment once they
-  // are. We also need to explicitly set a value for the props otherwise the
-  // callback won't be called.
-  {
-    DebugOnly<nsresult> rv = Preferences::RegisterCallbackAndCall(
-        &DnsPrefChanged, kPrefGetTtl, this);
-    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
-                         "Could not register DNS TTL pref callback.");
-    rv = Preferences::RegisterCallbackAndCall(&DnsPrefChanged,
-                                              kPrefNativeIsLocalhost, this);
-    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
-                         "Could not register DNS pref callback.");
-  }
-
 #if defined(HAVE_RES_NINIT)
   // We want to make sure the system is using the correct resolver settings,
   // so we force it to reload those settings whenever we startup a subsequent
@@ -242,7 +206,8 @@ nsresult nsHostResolver::Init() MOZ_NO_THREAD_SAFETY_ANALYSIS {
 
   // We can configure the threadpool to keep threads alive for a while after
   // the last ThreadFunc task has been executed.
-  int32_t poolTimeoutSecs = Preferences::GetInt(kPrefThreadIdleTime, 60);
+  int32_t poolTimeoutSecs =
+      StaticPrefs::network_dns_resolver_thread_extra_idle_time_seconds();
   uint32_t poolTimeoutMs;
   if (poolTimeoutSecs < 0) {
     // This means never shut down the idle threads
@@ -348,13 +313,6 @@ void nsHostResolver::FlushCache(bool aTrrToo) {
 void nsHostResolver::Shutdown() {
   LOG(("Shutting down host resolver.\n"));
 
-  {
-    DebugOnly<nsresult> rv =
-        Preferences::UnregisterCallback(&DnsPrefChanged, kPrefGetTtl, this);
-    NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
-                         "Could not unregister DNS TTL pref callback.");
-  }
-
   LinkedList<RefPtr<nsHostRecord>> pendingQHigh, pendingQMed, pendingQLow,
       evictionQ;
 
@@ -1330,7 +1288,8 @@ bool nsHostResolver::GetHostToLookup(nsHostRecord** result) {
     // remove next record from Q; hand over owning reference. Check high, then
     // med, then low
 
-#define SET_GET_TTL(var, val) (var)->StoreGetTtl(sGetTtlEnabled && (val))
+#define SET_GET_TTL(var, val) \
+  (var)->StoreGetTtl(StaticPrefs::network_dns_get_ttl() && (val))
 
     RefPtr<nsHostRecord> rec = mQueue.Dequeue(true, lock);
     if (rec) {
@@ -1400,7 +1359,7 @@ void nsHostResolver::PrepareRecordExpirationAddrRecord(
   unsigned int grace = StaticPrefs::network_dnsCacheExpirationGracePeriod();
 
   unsigned int ttl = StaticPrefs::network_dnsCacheExpiration();
-  if (sGetTtlEnabled || rec->addr_info->IsTRR()) {
+  if (StaticPrefs::network_dns_get_ttl() || rec->addr_info->IsTRR()) {
     if (rec->addr_info && rec->addr_info->TTL() != AddrInfo::NO_TTL_DATA) {
       ttl = rec->addr_info->TTL();
     }
@@ -1733,7 +1692,7 @@ nsHostResolver::LookupStatus nsHostResolver::CompleteLookupLocked(
     }
   }
   if (hasNativeResult && !mShutdown && !addrRec->LoadGetTtl() &&
-      !rec->mResolving && sGetTtlEnabled) {
+      !rec->mResolving && StaticPrefs::network_dns_get_ttl()) {
     LOG(("Issuing second async lookup for TTL for host [%s].",
          addrRec->host.get()));
     addrRec->flags =

netwerk/dns/nsHostResolver.h

@@ -53,8 +53,6 @@ static inline uint32_t MaxResolverThreads() {
   (((x) == nsIDNSService::MODE_NATIVEONLY) || \
    ((x) == nsIDNSService::MODE_TRROFF))
 
-extern mozilla::Atomic<bool, mozilla::Relaxed> gNativeIsLocalhost;
-
 #define MAX_NON_PRIORITY_REQUESTS 150
 
 class AHostResolver {