Merge changes I6e6b40b0,I6a0d93e0,Ie26f6e52

* changes:
  Revert "[CTT-5] Stop update TCP conntrack entry timeout"
  Revert "[CTT-6] Update TCP conntrack entry timeout while adding rules"
  Revert "[CTT-7] Delete the rules while half-closing tcp state entered"
This commit is contained in:
Treehugger Robot
2021-07-20 10:49:18 +00:00
committed by Gerrit Code Review
4 changed files with 49 additions and 173 deletions

View File

@@ -371,7 +371,6 @@ public class BpfCoordinatorShimImpl
} catch (IllegalStateException e) {
// Silent if the rule already exists. Note that the errno EEXIST was rethrown as
// IllegalStateException. See BpfMap#insertEntry.
return false;
}
return true;
}

View File

@@ -141,11 +141,6 @@ public abstract class BpfCoordinatorShim {
/**
* Adds a tethering IPv4 offload rule to appropriate BPF map.
*
* @param downstream true if downstream, false if upstream.
* @param key the key to add.
* @param value the value to add.
* @return true iff the map was modified, false if the key exists or there was an error.
*/
public abstract boolean tetherOffloadRuleAdd(boolean downstream, @NonNull Tether4Key key,
@NonNull Tether4Value value);

View File

@@ -124,21 +124,10 @@ public class BpfCoordinator {
return makeMapPath((downstream ? "downstream" : "upstream") + ipVersion);
}
// TODO: probably to remember what the timeout updated things to last is. But that requires
// either r/w map entries (which seems bad/racy) or a separate map to keep track of all flows
// and remember when they were updated and with what timeout.
@VisibleForTesting
static final int CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS = 60_000;
@VisibleForTesting
static final int CONNTRACK_TIMEOUT_UPDATE_SLACK_MS = 20_000;
// Default timeouts sync from /proc/sys/net/netfilter/nf_conntrack_*
// See also kernel document nf_conntrack-sysctl.txt.
@VisibleForTesting
static final int NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED = 432_000;
static final int NF_CONNTRACK_TCP_TIMEOUT_UNACKNOWLEDGED = 300;
// The default value is 120 for 5.10 and that thus the periodicity of the updates of 60s is
// low enough to support all ACK kernels.
@VisibleForTesting
static final int NF_CONNTRACK_UDP_TIMEOUT_STREAM = 180;
@@ -1578,34 +1567,8 @@ public class BpfCoordinator {
final Tether4Key downstream4Key = makeTetherDownstream4Key(e, tetherClient,
upstreamIndex);
final boolean isConntrackEventDelete =
e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
| NetlinkConstants.IPCTNL_MSG_CT_DELETE);
// Using the timeout to distinguish tcp state is not a decent way. Need to fix.
// The received IPCTNL_MSG_CT_NEW must pass ConntrackMonitor#isEstablishedNatSession
// which checks CTA_STATUS. It implies that this entry has at least reached tcp
// state "established". For safety, treat any timeout which is equal or larger than 300
// seconds (UNACKNOWLEDGED, ESTABLISHED, ..) to be "established".
// TODO: parse tcp state in conntrack monitor.
final boolean isTcpEstablished =
e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
| NetlinkConstants.IPCTNL_MSG_CT_NEW)
&& e.tupleOrig.protoNum == OsConstants.IPPROTO_TCP
&& (e.timeoutSec >= NF_CONNTRACK_TCP_TIMEOUT_UNACKNOWLEDGED);
final boolean isTcpNonEstablished =
e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
| NetlinkConstants.IPCTNL_MSG_CT_NEW)
&& e.tupleOrig.protoNum == OsConstants.IPPROTO_TCP
&& (e.timeoutSec < NF_CONNTRACK_TCP_TIMEOUT_UNACKNOWLEDGED);
// Delete the BPF rules:
// 1. Contrack event IPCTNL_MSG_CT_DELETE received.
// 2. For TCP conntrack entry, the tcp state has left "established" and going to be
// closed.
// TODO: continue to offload half-closed tcp connections.
if (isConntrackEventDelete || isTcpNonEstablished) {
if (e.msgType == (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8
| NetlinkConstants.IPCTNL_MSG_CT_DELETE)) {
final boolean deletedUpstream = mBpfCoordinatorShim.tetherOffloadRuleRemove(
UPSTREAM, upstream4Key);
final boolean deletedDownstream = mBpfCoordinatorShim.tetherOffloadRuleRemove(
@@ -1620,7 +1583,6 @@ public class BpfCoordinator {
Log.wtf(TAG, "The bidirectional rules should be removed concurrently ("
+ "upstream: " + deletedUpstream
+ ", downstream: " + deletedDownstream + ")");
// TODO: consider better error handling for the stubs {rule, limit, ..}.
return;
}
@@ -1631,41 +1593,11 @@ public class BpfCoordinator {
final Tether4Value upstream4Value = makeTetherUpstream4Value(e, upstreamIndex);
final Tether4Value downstream4Value = makeTetherDownstream4Value(e, tetherClient,
upstreamIndex);
maybeAddDevMap(upstreamIndex, tetherClient.downstreamIfindex);
maybeSetLimit(upstreamIndex);
final boolean upstreamAdded = mBpfCoordinatorShim.tetherOffloadRuleAdd(UPSTREAM,
upstream4Key, upstream4Value);
final boolean downstreamAdded = mBpfCoordinatorShim.tetherOffloadRuleAdd(DOWNSTREAM,
downstream4Key, downstream4Value);
if (upstreamAdded != downstreamAdded) {
mLog.e("The bidirectional rules should be added or not added concurrently ("
+ "upstream: " + upstreamAdded
+ ", downstream: " + downstreamAdded + "). "
+ "Remove the added rules.");
if (upstreamAdded) {
mBpfCoordinatorShim.tetherOffloadRuleRemove(UPSTREAM, upstream4Key);
}
if (downstreamAdded) {
mBpfCoordinatorShim.tetherOffloadRuleRemove(DOWNSTREAM, downstream4Key);
}
return;
}
// Update TCP timeout iif it is first time we're adding the rules. Needed because a
// payload data packet may have gone through non-offload path, before we added offload
// rules, and that this may result in in-kernel conntrack state being in ESTABLISHED
// but pending ACK (ie. UNACKED) state. But the in-kernel conntrack might never see the
// ACK because we just added offload rules. As such after adding the rules we need to
// force the timeout back to the normal ESTABLISHED timeout of 5 days. Note that
// updating the timeout will trigger another netlink event with the updated timeout.
// TODO: Remove this once the tcp state is parsed.
if (isTcpEstablished && upstreamAdded && downstreamAdded) {
updateConntrackTimeout((byte) upstream4Key.l4proto,
parseIPv4Address(upstream4Key.src4), (short) upstream4Key.srcPort,
parseIPv4Address(upstream4Key.dst4), (short) upstream4Key.dstPort);
}
mBpfCoordinatorShim.tetherOffloadRuleAdd(UPSTREAM, upstream4Key, upstream4Value);
mBpfCoordinatorShim.tetherOffloadRuleAdd(DOWNSTREAM, downstream4Key, downstream4Value);
}
}
@@ -1948,7 +1880,6 @@ public class BpfCoordinator {
// - proc/sys/net/netfilter/nf_conntrack_tcp_timeout_established
// - proc/sys/net/netfilter/nf_conntrack_udp_timeout_stream
// See kernel document nf_conntrack-sysctl.txt.
// TODO: we should account for the fact that lastUsed is in the past and not exactly now.
final int timeoutSec = (proto == OsConstants.IPPROTO_TCP)
? NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED
: NF_CONNTRACK_UDP_TIMEOUT_STREAM;
@@ -1979,23 +1910,6 @@ public class BpfCoordinator {
}
}
boolean requireConntrackTimeoutUpdate(long nowNs, long lastUsedNs, int proto) {
// Refreshing tcp timeout without checking tcp state may make the conntrack entry live
// 5 days (432000s) even while the session is being closed. Its BPF rule may not be
// deleted for 5 days because the tcp state gets stuck and conntrack delete message is
// not sent. Note that both the conntrack monitor and refreshing timeout updater are
// in the same thread. Beware while the tcp status may be changed running in refreshing
// timeout updater and may read out-of-date tcp stats.
// See nf_conntrack_tcp_timeout_established in kernel document.
// TODO: support refreshing TCP conntrack timeout.
if (proto == OsConstants.IPPROTO_TCP) return false;
// The timeout requirement check needs the slack time because the scheduled timer may
// be not precise. The timeout update has a chance to be missed.
return (nowNs - lastUsedNs) < (long) (CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS
+ CONNTRACK_TIMEOUT_UPDATE_SLACK_MS) * 1_000_000;
}
private void refreshAllConntrackTimeouts() {
final long now = mDeps.elapsedRealtimeNanos();
@@ -2003,7 +1917,7 @@ public class BpfCoordinator {
// because TCP is a bidirectional traffic. Probably don't need to extend timeout by
// both directions for TCP.
mBpfCoordinatorShim.tetherOffloadRuleForEach(UPSTREAM, (k, v) -> {
if (requireConntrackTimeoutUpdate(now, v.lastUsed, k.l4proto)) {
if ((now - v.lastUsed) / 1_000_000 < CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS) {
updateConntrackTimeout((byte) k.l4proto,
parseIPv4Address(k.src4), (short) k.srcPort,
parseIPv4Address(k.dst4), (short) k.dstPort);
@@ -2011,10 +1925,10 @@ public class BpfCoordinator {
});
// Reverse the source and destination {address, port} from downstream value because
// #updateConntrackTimeout refreshes the timeout of netlink attribute CTA_TUPLE_ORIG
// #updateConntrackTimeout refresh the timeout of netlink attribute CTA_TUPLE_ORIG
// which is opposite direction for downstream map value.
mBpfCoordinatorShim.tetherOffloadRuleForEach(DOWNSTREAM, (k, v) -> {
if (requireConntrackTimeoutUpdate(now, v.lastUsed, k.l4proto)) {
if ((now - v.lastUsed) / 1_000_000 < CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS) {
updateConntrackTimeout((byte) k.l4proto,
parseIPv4Address(v.dst46), (short) v.dstPort,
parseIPv4Address(v.src46), (short) v.srcPort);

View File

@@ -41,7 +41,6 @@ import static android.system.OsConstants.NETLINK_NETFILTER;
import static com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn;
import static com.android.dx.mockito.inline.extended.ExtendedMockito.staticMockMarker;
import static com.android.networkstack.tethering.BpfCoordinator.CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS;
import static com.android.networkstack.tethering.BpfCoordinator.CONNTRACK_TIMEOUT_UPDATE_SLACK_MS;
import static com.android.networkstack.tethering.BpfCoordinator.NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED;
import static com.android.networkstack.tethering.BpfCoordinator.NF_CONNTRACK_UDP_TIMEOUT_STREAM;
import static com.android.networkstack.tethering.BpfCoordinator.StatsType;
@@ -1379,14 +1378,8 @@ public class BpfCoordinatorTest {
}
final int status = (msgType == IPCTNL_MSG_CT_NEW) ? ESTABLISHED_MASK : DYING_MASK;
int timeoutSec;
if (msgType == IPCTNL_MSG_CT_NEW) {
timeoutSec = (proto == IPPROTO_TCP)
? NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED
: NF_CONNTRACK_UDP_TIMEOUT_STREAM;
} else {
timeoutSec = 0; /* unused, CT_DELETE */
}
final int timeoutSec = (msgType == IPCTNL_MSG_CT_NEW) ? 100 /* nonzero, new */
: 0 /* unused, delete */;
return new ConntrackEvent(
(short) (NetlinkConstants.NFNL_SUBSYS_CTNETLINK << 8 | msgType),
new Tuple(new TupleIpv4(PRIVATE_ADDR, REMOTE_ADDR),
@@ -1542,27 +1535,23 @@ public class BpfCoordinatorTest {
}
private void checkRefreshConntrackTimeout(final TestBpfMap<Tether4Key, Tether4Value> bpfMap,
int proto, final Tether4Key key, final Tether4Value value) throws Exception {
if (proto != IPPROTO_TCP && proto != IPPROTO_UDP) {
fail("Not support protocol " + proto);
}
final Tether4Key tcpKey, final Tether4Value tcpValue, final Tether4Key udpKey,
final Tether4Value udpValue) throws Exception {
// Both system elapsed time since boot and the rule last used time are used to measure
// the rule expiration. In this test, all test rules are fixed the last used time to 0.
// Set the different testing elapsed time to make the rule to be valid or expired.
//
// Timeline:
// CONNTRACK_TIMEOUT_UPDATE_SLACK_MS
// ->| |<-
// +---+---+---+---+---+--...--+---+---+---+---+---+-..-+---+-- ..
// | CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS |
// +---+---+---+---+---+--...--+---+---+---+---+---+-..-+---+-- ..
// |<- valid diff ->|
// |<- expired diff ->|
// ^ ^ ^
// last used time elapsed time (valid) elapsed time (expired)
final long validTimeNs = CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS * 1_000_000L;
final long expiredTimeNs = (CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS
+ CONNTRACK_TIMEOUT_UPDATE_SLACK_MS + 1) * 1_000_000L;
// 0 60 (seconds)
// +---+---+---+---+--...--+---+---+---+---+---+- ..
// | CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS |
// +---+---+---+---+--...--+---+---+---+---+---+- ..
// |<- valid diff ->|
// |<- expired diff ->|
// ^ ^ ^
// last used time elapsed time (valid) elapsed time (expired)
final long validTime = (CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS - 1) * 1_000_000L;
final long expiredTime = (CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS + 1) * 1_000_000L;
// Static mocking for NetlinkSocket.
MockitoSession mockSession = ExtendedMockito.mockitoSession()
@@ -1571,27 +1560,30 @@ public class BpfCoordinatorTest {
try {
final BpfCoordinator coordinator = makeBpfCoordinator();
coordinator.startPolling();
bpfMap.insertEntry(key, value);
bpfMap.insertEntry(tcpKey, tcpValue);
bpfMap.insertEntry(udpKey, udpValue);
// [1] Don't refresh contrack timeout.
setElapsedRealtimeNanos(expiredTimeNs);
setElapsedRealtimeNanos(expiredTime);
mTestLooper.moveTimeForward(CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS);
waitForIdle();
ExtendedMockito.verifyNoMoreInteractions(staticMockMarker(NetlinkSocket.class));
ExtendedMockito.clearInvocations(staticMockMarker(NetlinkSocket.class));
// [2] Refresh contrack timeout. UDP Only.
setElapsedRealtimeNanos(validTimeNs);
// [2] Refresh contrack timeout.
setElapsedRealtimeNanos(validTime);
mTestLooper.moveTimeForward(CONNTRACK_TIMEOUT_UPDATE_INTERVAL_MS);
waitForIdle();
if (proto == IPPROTO_UDP) {
final byte[] expectedNetlinkUdp = ConntrackMessage.newIPv4TimeoutUpdateRequest(
IPPROTO_UDP, PRIVATE_ADDR, (int) PRIVATE_PORT, REMOTE_ADDR,
(int) REMOTE_PORT, NF_CONNTRACK_UDP_TIMEOUT_STREAM);
ExtendedMockito.verify(() -> NetlinkSocket.sendOneShotKernelMessage(
eq(NETLINK_NETFILTER), eq(expectedNetlinkUdp)));
}
final byte[] expectedNetlinkTcp = ConntrackMessage.newIPv4TimeoutUpdateRequest(
IPPROTO_TCP, PRIVATE_ADDR, (int) PRIVATE_PORT, REMOTE_ADDR,
(int) REMOTE_PORT, NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED);
final byte[] expectedNetlinkUdp = ConntrackMessage.newIPv4TimeoutUpdateRequest(
IPPROTO_UDP, PRIVATE_ADDR, (int) PRIVATE_PORT, REMOTE_ADDR,
(int) REMOTE_PORT, NF_CONNTRACK_UDP_TIMEOUT_STREAM);
ExtendedMockito.verify(() -> NetlinkSocket.sendOneShotKernelMessage(
eq(NETLINK_NETFILTER), eq(expectedNetlinkTcp)));
ExtendedMockito.verify(() -> NetlinkSocket.sendOneShotKernelMessage(
eq(NETLINK_NETFILTER), eq(expectedNetlinkUdp)));
ExtendedMockito.verifyNoMoreInteractions(staticMockMarker(NetlinkSocket.class));
ExtendedMockito.clearInvocations(staticMockMarker(NetlinkSocket.class));
@@ -1608,57 +1600,33 @@ public class BpfCoordinatorTest {
@Test
@IgnoreUpTo(Build.VERSION_CODES.R)
public void testRefreshConntrackTimeout_Upstream4MapTcp() throws Exception {
public void testRefreshConntrackTimeout_Upstream4Map() throws Exception {
// TODO: Replace the dependencies BPF map with a non-mocked TestBpfMap object.
final TestBpfMap<Tether4Key, Tether4Value> bpfUpstream4Map =
new TestBpfMap<>(Tether4Key.class, Tether4Value.class);
doReturn(bpfUpstream4Map).when(mDeps).getBpfUpstream4Map();
final Tether4Key key = makeUpstream4Key(IPPROTO_TCP);
final Tether4Value value = makeUpstream4Value();
final Tether4Key tcpKey = makeUpstream4Key(IPPROTO_TCP);
final Tether4Key udpKey = makeUpstream4Key(IPPROTO_UDP);
final Tether4Value tcpValue = makeUpstream4Value();
final Tether4Value udpValue = makeUpstream4Value();
checkRefreshConntrackTimeout(bpfUpstream4Map, IPPROTO_TCP, key, value);
checkRefreshConntrackTimeout(bpfUpstream4Map, tcpKey, tcpValue, udpKey, udpValue);
}
@Test
@IgnoreUpTo(Build.VERSION_CODES.R)
public void testRefreshConntrackTimeout_Upstream4MapUdp() throws Exception {
// TODO: Replace the dependencies BPF map with a non-mocked TestBpfMap object.
final TestBpfMap<Tether4Key, Tether4Value> bpfUpstream4Map =
new TestBpfMap<>(Tether4Key.class, Tether4Value.class);
doReturn(bpfUpstream4Map).when(mDeps).getBpfUpstream4Map();
final Tether4Key key = makeUpstream4Key(IPPROTO_UDP);
final Tether4Value value = makeUpstream4Value();
checkRefreshConntrackTimeout(bpfUpstream4Map, IPPROTO_UDP, key, value);
}
@Test
@IgnoreUpTo(Build.VERSION_CODES.R)
public void testRefreshConntrackTimeout_Downstream4MapTcp() throws Exception {
public void testRefreshConntrackTimeout_Downstream4Map() throws Exception {
// TODO: Replace the dependencies BPF map with a non-mocked TestBpfMap object.
final TestBpfMap<Tether4Key, Tether4Value> bpfDownstream4Map =
new TestBpfMap<>(Tether4Key.class, Tether4Value.class);
doReturn(bpfDownstream4Map).when(mDeps).getBpfDownstream4Map();
final Tether4Key key = makeDownstream4Key(IPPROTO_TCP);
final Tether4Value value = makeDownstream4Value();
final Tether4Key tcpKey = makeDownstream4Key(IPPROTO_TCP);
final Tether4Key udpKey = makeDownstream4Key(IPPROTO_UDP);
final Tether4Value tcpValue = makeDownstream4Value();
final Tether4Value udpValue = makeDownstream4Value();
checkRefreshConntrackTimeout(bpfDownstream4Map, IPPROTO_TCP, key, value);
}
@Test
@IgnoreUpTo(Build.VERSION_CODES.R)
public void testRefreshConntrackTimeout_Downstream4MapUdp() throws Exception {
// TODO: Replace the dependencies BPF map with a non-mocked TestBpfMap object.
final TestBpfMap<Tether4Key, Tether4Value> bpfDownstream4Map =
new TestBpfMap<>(Tether4Key.class, Tether4Value.class);
doReturn(bpfDownstream4Map).when(mDeps).getBpfDownstream4Map();
final Tether4Key key = makeDownstream4Key(IPPROTO_UDP);
final Tether4Value value = makeDownstream4Value();
checkRefreshConntrackTimeout(bpfDownstream4Map, IPPROTO_UDP, key, value);
checkRefreshConntrackTimeout(bpfDownstream4Map, tcpKey, tcpValue, udpKey, udpValue);
}
}