Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit cf37ca43 authored by Lorenzo Colitti's avatar Lorenzo Colitti
Browse files

Don't crash if the PREF64 expires when IpClient is stopped. 

Currently the code does not cancel the PREF64 alarm when IpClient
is stopped. If the alarm fires when IpClient has disconnected, it
will call updatePref64 with a null prefix, which will crash.

Ensure that the alarm is cancelled when IpClient is stopped.

Bug: 153694684
Bug: 155559286
Test: new unit tests
Change-Id: I397eb36c1a8ecf1324de33e720577fe2e4e07056
parent a4709152

src/android/net/ip/IpClientLinkObserver.java

+13 −4
Original line number Original line Diff line number Diff line
@@ -238,6 +238,7 @@ public class IpClientLinkObserver implements NetworkObserver { 
        // while interfaceDnsServerInfo() is being called, we'll end up with no DNS servers in

        // while interfaceDnsServerInfo() is being called, we'll end up with no DNS servers in

        // mLinkProperties, as desired.

        // mLinkProperties, as desired.

        mDnsServerRepository = new DnsServerRepository(mConfig.minRdnssLifetime);

        mDnsServerRepository = new DnsServerRepository(mConfig.minRdnssLifetime);

        mNetlinkMonitor.clearAlarms();

        mLinkProperties.clear();

        mLinkProperties.clear();

        mLinkProperties.setInterfaceName(mInterfaceName);

        mLinkProperties.setInterfaceName(mInterfaceName);

    }

    }
@@ -281,18 +282,27 @@ public class IpClientLinkObserver implements NetworkObserver { 
            mIfindex = ifindex;

            mIfindex = ifindex;

        }

        }





        void clearAlarms() {

            cancelPref64Alarm();

        }



        private final AlarmManager.OnAlarmListener mExpirePref64Alarm = () -> {

        private final AlarmManager.OnAlarmListener mExpirePref64Alarm = () -> {

            // Ignore the alarm if cancelPref64Alarm has already been called.

            //

            // TODO: in the rare case where the alarm fires and posts the lambda to the handler

            // TODO: in the rare case where the alarm fires and posts the lambda to the handler

            // thread while we are processing an RA that changes the lifetime of the same prefix,

            // thread while we are processing an RA that changes the lifetime of the same prefix,

            // this code will run anyway even if the alarm is rescheduled or cancelled. If the

            // this code will run anyway even if the alarm is rescheduled or cancelled. If the

            // lifetime in the RA is zero this doesn't matter (we just harmlessly cancel the alarm

            // lifetime in the RA is zero this code will correctly do nothing, but if the lifetime

            // one extra time) but if the lifetime is nonzero then the prefix will be added and

            // is nonzero then the prefix will be added and immediately removed by this code.

            // immediately removed by this code.

            if (mNat64PrefixExpiry == 0) return;

            updatePref64(mShim.getNat64Prefix(mLinkProperties),

            updatePref64(mShim.getNat64Prefix(mLinkProperties),

                    mNat64PrefixExpiry, mNat64PrefixExpiry);

                    mNat64PrefixExpiry, mNat64PrefixExpiry);

        };

        };





        private void cancelPref64Alarm() {

        private void cancelPref64Alarm() {

            // Clear the expiry in case the alarm just fired and has not been processed yet.

            if (mNat64PrefixExpiry == 0) return;

            mNat64PrefixExpiry = 0;

            mAlarmManager.cancel(mExpirePref64Alarm);

            mAlarmManager.cancel(mExpirePref64Alarm);

        }

        }
@@ -342,7 +352,6 @@ public class IpClientLinkObserver implements NetworkObserver { 
                schedulePref64Alarm();

                schedulePref64Alarm();

            } else {

            } else {

                mShim.setNat64Prefix(mLinkProperties, null);

                mShim.setNat64Prefix(mLinkProperties, null);

                mNat64PrefixExpiry = 0;

                cancelPref64Alarm();

                cancelPref64Alarm();

            }

            }

tests/integration/src/android/net/ip/IpClientIntegrationTest.java

+19 −0
Original line number Original line Diff line number Diff line
@@ -1527,6 +1527,25 @@ public class IpClientIntegrationTest { 
        mIpc.getHandler().post(() -> lastAlarm.onAlarm());

        mIpc.getHandler().post(() -> lastAlarm.onAlarm());

        expectAlarmCancelled(inOrder, pref64Alarm);

        expectAlarmCancelled(inOrder, pref64Alarm);

        expectNat64PrefixUpdate(inOrder, null);

        expectNat64PrefixUpdate(inOrder, null);



        // Re-announce the prefix.

        pref64 = new StructNdOptPref64(prefix, 600).toByteBuffer();

        ra = buildRaPacket(pio, rdnss, pref64);

        mPacketReader.sendResponse(ra);

        final OnAlarmListener clearAlarm = expectAlarmSet(inOrder, "PREF64", 600);

        expectNat64PrefixUpdate(inOrder, prefix);

        reset(mCb, mAlarm);



        // Check that the alarm is cancelled when IpClient is stopped.

        mIpc.stop();

        HandlerUtilsKt.waitForIdle(mIpc.getHandler(), TEST_TIMEOUT_MS);

        expectAlarmCancelled(inOrder, clearAlarm);

        expectNat64PrefixUpdate(inOrder, null);



        // Check that even if the alarm was already in the message queue while it was cancelled, it

        // is safely ignored.

        mIpc.getHandler().post(() -> clearAlarm.onAlarm());

        HandlerUtilsKt.waitForIdle(mIpc.getHandler(), TEST_TIMEOUT_MS);

    }

    }





    private void addIpAddressAndWaitForIt(final String iface) throws Exception {

    private void addIpAddressAndWaitForIt(final String iface) throws Exception {