Fix use of reachable DNS server logic
Move reachable DNS server computation out of ConnectivityService
and split it into LinkProperties#isReachable() and a companion
change in WifiStateMachine's makeLinkProperties().
Restore previous ConnectivityService#updateDnses() behaviour, as
the pruning is done in WifiStateMachine now.
Bug: 19470192
Bug: 20733156
Bug: 22098233
Change-Id: I810ef74d504e5dc1ca2017d435cdadd6b82171e6
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 47971a1..8fba98c 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -140,14 +140,12 @@
import java.io.IOException;
import java.io.PrintWriter;
import java.net.Inet4Address;
-import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
-import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
@@ -4014,51 +4012,10 @@
return !routeDiff.added.isEmpty() || !routeDiff.removed.isEmpty();
}
- // TODO: investigate moving this into LinkProperties, if only to make more accurate
- // the isProvisioned() checks.
- private static Collection<InetAddress> getLikelyReachableDnsServers(LinkProperties lp) {
- final ArrayList<InetAddress> dnsServers = new ArrayList<InetAddress>();
- final List<RouteInfo> allRoutes = lp.getAllRoutes();
- for (InetAddress nameserver : lp.getDnsServers()) {
- // If the LinkProperties doesn't include a route to the nameserver, ignore it.
- final RouteInfo bestRoute = RouteInfo.selectBestRoute(allRoutes, nameserver);
- if (bestRoute == null) {
- continue;
- }
-
- // TODO: better source address evaluation for destination addresses.
- if (nameserver instanceof Inet4Address) {
- if (!lp.hasIPv4Address()) {
- continue;
- }
- } else if (nameserver instanceof Inet6Address) {
- if (nameserver.isLinkLocalAddress()) {
- if (((Inet6Address)nameserver).getScopeId() == 0) {
- // For now, just make sure link-local DNS servers have
- // scopedIds set, since DNS lookups will fail otherwise.
- // TODO: verify the scopeId matches that of lp's interface.
- continue;
- }
- } else {
- if (bestRoute.isIPv6Default() && !lp.hasGlobalIPv6Address()) {
- // TODO: reconsider all corner cases (disconnected ULA networks, ...).
- continue;
- }
- }
- }
-
- dnsServers.add(nameserver);
- }
- return Collections.unmodifiableList(dnsServers);
- }
-
private void updateDnses(LinkProperties newLp, LinkProperties oldLp, int netId,
boolean flush, boolean useDefaultDns) {
- // TODO: consider comparing the getLikelyReachableDnsServers() lists, in case the
- // route to a DNS server has been removed (only really applicable in special cases
- // where there is no default route).
if (oldLp == null || (newLp.isIdenticalDnses(oldLp) == false)) {
- Collection<InetAddress> dnses = getLikelyReachableDnsServers(newLp);
+ Collection<InetAddress> dnses = newLp.getDnsServers();
if (dnses.size() == 0 && mDefaultDns != null && useDefaultDns) {
dnses = new ArrayList();
dnses.add(mDefaultDns);