LineageOS/android_packages_modules_Connectivity
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Implement ConnectivityService TODO and fix many race conditions

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This patch implements an outstanding TODO in ConnectivityService to add
synchronization over the map of network request ids to network agent
info objects.

This structure is accessed from multiple threads:
 - Binder thread on public aidl methods, most notably via
   getDefaultNetwork().
 - Internal handler.

This leads to many race conditions that can crash the system server and
reboot the phone if getDefaultNetwork() is called on a Binder thread to
service a public ConnectivityManager api while the default network state
is being updated on the internal handler after losing the default
network.

Bug: 65911184
Test: runtest frameworks-net
Merged-In: I86c830ebd559e31d4576a7606705a056afb064ac
Merged-In: I2011e23c9f894c079ab66cd7cc5c14af572a956d
Merged-In: Ic70901a6aa22a03e97f494e793920ab07a0fd612
Merged-In: I4a7658e1fa6946063ab86a251269413903841ee8
Merged-In: Ia59d45f4e95a536d7982f61ac9c9a1bfc5e8ebb8

(cherry picked from commit cd95278e55bd0e4935f42214d964f8c6aa52b4ea)

Change-Id: I2e26bef9eddd342f51c02b991632c7ea04fe7e66
This commit is contained in:
Hugo Benichi
2017-09-20 11:20:14 +09:00
parent b3dec17660
commit f15fc752c5
1 changed files with 32 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
services/core/java/com/android/server/ConnectivityService.java
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@@ -2201,7 +2201,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
// A network factory has connected. Send it all current NetworkRequests.
for (NetworkRequestInfo nri : mNetworkRequests.values()) {
if (nri.request.isListen()) continue;
NetworkAgentInfo nai = mNetworkForRequestId.get(nri.request.requestId);
NetworkAgentInfo nai = getNetworkForRequest(nri.request.requestId);
ac.sendMessage(android.net.NetworkFactory.CMD_REQUEST_NETWORK,
(nai != null ? nai.getCurrentScore() : 0), 0, nri.request);
}
@@ -2278,9 +2278,9 @@ public class ConnectivityService extends IConnectivityManager.Stub
// Remove all previously satisfied requests.
for (int i = 0; i < nai.numNetworkRequests(); i++) {
NetworkRequest request = nai.requestAt(i);
NetworkAgentInfo currentNetwork = mNetworkForRequestId.get(request.requestId);
NetworkAgentInfo currentNetwork = getNetworkForRequest(request.requestId);
if (currentNetwork != null && currentNetwork.network.netId == nai.network.netId) {
mNetworkForRequestId.remove(request.requestId);
clearNetworkForRequest(request.requestId);
sendUpdatedScoreToFactories(request, 0);
}
}
@@ -2356,7 +2356,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
}
}
rematchAllNetworksAndRequests(null, 0);
if (nri.request.isRequest() && mNetworkForRequestId.get(nri.request.requestId) == null) {
if (nri.request.isRequest() && getNetworkForRequest(nri.request.requestId) == null) {
sendUpdatedScoreToFactories(nri.request, 0);
}
}
@@ -2411,7 +2411,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
// 2. Unvalidated WiFi will not be reaped when validated cellular
// is currently satisfying the request. This is desirable when
// WiFi ends up validating and out scoring cellular.
mNetworkForRequestId.get(nri.request.requestId).getCurrentScore() <
getNetworkForRequest(nri.request.requestId).getCurrentScore() <
nai.getCurrentScoreAsValidated())) {
return false;
}
@@ -2438,7 +2438,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
if (mNetworkRequests.get(nri.request) == null) {
return;
}
if (mNetworkForRequestId.get(nri.request.requestId) != null) {
if (getNetworkForRequest(nri.request.requestId) != null) {
return;
}
if (VDBG || (DBG && nri.request.isRequest())) {
@@ -2478,7 +2478,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
mNetworkRequestInfoLogs.log("RELEASE " + nri);
if (nri.request.isRequest()) {
boolean wasKept = false;
NetworkAgentInfo nai = mNetworkForRequestId.get(nri.request.requestId);
NetworkAgentInfo nai = getNetworkForRequest(nri.request.requestId);
if (nai != null) {
boolean wasBackgroundNetwork = nai.isBackgroundNetwork();
nai.removeRequest(nri.request.requestId);
@@ -2495,7 +2495,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
} else {
wasKept = true;
}
mNetworkForRequestId.remove(nri.request.requestId);
clearNetworkForRequest(nri.request.requestId);
if (!wasBackgroundNetwork && nai.isBackgroundNetwork()) {
// Went from foreground to background.
updateCapabilities(nai.getCurrentScore(), nai, nai.networkCapabilities);
@@ -4286,7 +4286,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
* and the are the highest scored network available.
* the are keyed off the Requests requestId.
*/
// TODO: Yikes, this is accessed on multiple threads: add synchronization.
// NOTE: Accessed on multiple threads, must be synchronized on itself.
@GuardedBy("mNetworkForRequestId")
private final SparseArray<NetworkAgentInfo> mNetworkForRequestId =
new SparseArray<NetworkAgentInfo>();
@@ -4316,8 +4317,26 @@ public class ConnectivityService extends IConnectivityManager.Stub
// priority networks like Wi-Fi are active.
private final NetworkRequest mDefaultMobileDataRequest;
private NetworkAgentInfo getNetworkForRequest(int requestId) {
synchronized (mNetworkForRequestId) {
return mNetworkForRequestId.get(requestId);
}
}
private void clearNetworkForRequest(int requestId) {
synchronized (mNetworkForRequestId) {
mNetworkForRequestId.remove(requestId);
}
}
private void setNetworkForRequest(int requestId, NetworkAgentInfo nai) {
synchronized (mNetworkForRequestId) {
mNetworkForRequestId.put(requestId, nai);
}
}
private NetworkAgentInfo getDefaultNetwork() {
return mNetworkForRequestId.get(mDefaultRequest.requestId);
return getNetworkForRequest(mDefaultRequest.requestId);
}
private boolean isDefaultNetwork(NetworkAgentInfo nai) {
@@ -4879,7 +4898,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
// requests or not, and doesn't affect the network's score.
if (nri.request.isListen()) continue;
final NetworkAgentInfo currentNetwork = mNetworkForRequestId.get(nri.request.requestId);
final NetworkAgentInfo currentNetwork = getNetworkForRequest(nri.request.requestId);
final boolean satisfies = newNetwork.satisfies(nri.request);
if (newNetwork == currentNetwork && satisfies) {
if (VDBG) {
@@ -4911,7 +4930,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
if (VDBG) log(" accepting network in place of null");
}
newNetwork.unlingerRequest(nri.request);
mNetworkForRequestId.put(nri.request.requestId, newNetwork);
setNetworkForRequest(nri.request.requestId, newNetwork);
if (!newNetwork.addRequest(nri.request)) {
Slog.wtf(TAG, "BUG: " + newNetwork.name() + " already has " + nri.request);
}
@@ -4945,7 +4964,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
}
newNetwork.removeRequest(nri.request.requestId);
if (currentNetwork == newNetwork) {
mNetworkForRequestId.remove(nri.request.requestId);
clearNetworkForRequest(nri.request.requestId);
sendUpdatedScoreToFactories(nri.request, 0);
} else {
Slog.wtf(TAG, "BUG: Removing request " + nri.request.requestId + " from " +