| /* |
| * Copyright (C) 2007 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.internal.os; |
| |
| import static android.system.OsConstants.F_SETFD; |
| import static android.system.OsConstants.O_CLOEXEC; |
| import static android.system.OsConstants.POLLIN; |
| |
| import static com.android.internal.os.ZygoteConnectionConstants.CONNECTION_TIMEOUT_MILLIS; |
| import static com.android.internal.os.ZygoteConnectionConstants.WRAPPED_PID_TIMEOUT_MILLIS; |
| |
| import android.annotation.UnsupportedAppUsage; |
| import android.content.pm.ApplicationInfo; |
| import android.net.Credentials; |
| import android.net.LocalSocket; |
| import android.os.Parcel; |
| import android.os.Process; |
| import android.os.Trace; |
| import android.system.ErrnoException; |
| import android.system.Os; |
| import android.system.StructPollfd; |
| import android.util.Log; |
| |
| import dalvik.system.VMRuntime; |
| |
| import libcore.io.IoUtils; |
| |
| import java.io.BufferedReader; |
| import java.io.ByteArrayInputStream; |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.nio.charset.StandardCharsets; |
| import java.util.Base64; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * A connection that can make spawn requests. |
| */ |
| class ZygoteConnection { |
| private static final String TAG = "Zygote"; |
| |
| /** |
| * The command socket. |
| * |
| * mSocket is retained in the child process in "peer wait" mode, so |
| * that it closes when the child process terminates. In other cases, |
| * it is closed in the peer. |
| */ |
| @UnsupportedAppUsage |
| private final LocalSocket mSocket; |
| @UnsupportedAppUsage |
| private final DataOutputStream mSocketOutStream; |
| private final BufferedReader mSocketReader; |
| @UnsupportedAppUsage |
| private final Credentials peer; |
| private final String abiList; |
| private boolean isEof; |
| |
| /** |
| * Constructs instance from connected socket. |
| * |
| * @param socket non-null; connected socket |
| * @param abiList non-null; a list of ABIs this zygote supports. |
| * @throws IOException If obtaining the peer credentials fails |
| */ |
| ZygoteConnection(LocalSocket socket, String abiList) throws IOException { |
| mSocket = socket; |
| this.abiList = abiList; |
| |
| mSocketOutStream = new DataOutputStream(socket.getOutputStream()); |
| mSocketReader = |
| new BufferedReader( |
| new InputStreamReader(socket.getInputStream()), Zygote.SOCKET_BUFFER_SIZE); |
| |
| mSocket.setSoTimeout(CONNECTION_TIMEOUT_MILLIS); |
| |
| try { |
| peer = mSocket.getPeerCredentials(); |
| } catch (IOException ex) { |
| Log.e(TAG, "Cannot read peer credentials", ex); |
| throw ex; |
| } |
| |
| isEof = false; |
| } |
| |
| /** |
| * Returns the file descriptor of the associated socket. |
| * |
| * @return null-ok; file descriptor |
| */ |
| FileDescriptor getFileDescriptor() { |
| return mSocket.getFileDescriptor(); |
| } |
| |
| /** |
| * Reads one start command from the command socket. If successful, a child is forked and a |
| * {@code Runnable} that calls the childs main method (or equivalent) is returned in the child |
| * process. {@code null} is always returned in the parent process (the zygote). |
| * |
| * If the client closes the socket, an {@code EOF} condition is set, which callers can test |
| * for by calling {@code ZygoteConnection.isClosedByPeer}. |
| */ |
| Runnable processOneCommand(ZygoteServer zygoteServer) { |
| String[] args; |
| |
| try { |
| args = Zygote.readArgumentList(mSocketReader); |
| } catch (IOException ex) { |
| throw new IllegalStateException("IOException on command socket", ex); |
| } |
| |
| // readArgumentList returns null only when it has reached EOF with no available |
| // data to read. This will only happen when the remote socket has disconnected. |
| if (args == null) { |
| isEof = true; |
| return null; |
| } |
| |
| int pid; |
| FileDescriptor childPipeFd = null; |
| FileDescriptor serverPipeFd = null; |
| |
| ZygoteArguments parsedArgs = new ZygoteArguments(args); |
| |
| if (parsedArgs.mBootCompleted) { |
| handleBootCompleted(); |
| return null; |
| } |
| |
| if (parsedArgs.mAbiListQuery) { |
| handleAbiListQuery(); |
| return null; |
| } |
| |
| if (parsedArgs.mPidQuery) { |
| handlePidQuery(); |
| return null; |
| } |
| |
| if (parsedArgs.mUsapPoolStatusSpecified) { |
| return handleUsapPoolStatusChange(zygoteServer, parsedArgs.mUsapPoolEnabled); |
| } |
| |
| if (parsedArgs.mPreloadDefault) { |
| handlePreload(); |
| return null; |
| } |
| |
| if (parsedArgs.mPreloadPackage != null) { |
| handlePreloadPackage(parsedArgs.mPreloadPackage, parsedArgs.mPreloadPackageLibs, |
| parsedArgs.mPreloadPackageLibFileName, parsedArgs.mPreloadPackageCacheKey); |
| return null; |
| } |
| |
| if (canPreloadApp() && parsedArgs.mPreloadApp != null) { |
| byte[] rawParcelData = Base64.getDecoder().decode(parsedArgs.mPreloadApp); |
| Parcel appInfoParcel = Parcel.obtain(); |
| appInfoParcel.unmarshall(rawParcelData, 0, rawParcelData.length); |
| appInfoParcel.setDataPosition(0); |
| ApplicationInfo appInfo = ApplicationInfo.CREATOR.createFromParcel(appInfoParcel); |
| appInfoParcel.recycle(); |
| if (appInfo != null) { |
| handlePreloadApp(appInfo); |
| } else { |
| throw new IllegalArgumentException("Failed to deserialize --preload-app"); |
| } |
| return null; |
| } |
| |
| if (parsedArgs.mApiBlacklistExemptions != null) { |
| return handleApiBlacklistExemptions(zygoteServer, parsedArgs.mApiBlacklistExemptions); |
| } |
| |
| if (parsedArgs.mHiddenApiAccessLogSampleRate != -1 |
| || parsedArgs.mHiddenApiAccessStatslogSampleRate != -1) { |
| return handleHiddenApiAccessLogSampleRate(zygoteServer, |
| parsedArgs.mHiddenApiAccessLogSampleRate, |
| parsedArgs.mHiddenApiAccessStatslogSampleRate); |
| } |
| |
| if (parsedArgs.mPermittedCapabilities != 0 || parsedArgs.mEffectiveCapabilities != 0) { |
| throw new ZygoteSecurityException("Client may not specify capabilities: " |
| + "permitted=0x" + Long.toHexString(parsedArgs.mPermittedCapabilities) |
| + ", effective=0x" + Long.toHexString(parsedArgs.mEffectiveCapabilities)); |
| } |
| |
| Zygote.applyUidSecurityPolicy(parsedArgs, peer); |
| Zygote.applyInvokeWithSecurityPolicy(parsedArgs, peer); |
| |
| Zygote.applyDebuggerSystemProperty(parsedArgs); |
| Zygote.applyInvokeWithSystemProperty(parsedArgs); |
| |
| int[][] rlimits = null; |
| |
| if (parsedArgs.mRLimits != null) { |
| rlimits = parsedArgs.mRLimits.toArray(Zygote.INT_ARRAY_2D); |
| } |
| |
| int[] fdsToIgnore = null; |
| |
| if (parsedArgs.mInvokeWith != null) { |
| try { |
| FileDescriptor[] pipeFds = Os.pipe2(O_CLOEXEC); |
| childPipeFd = pipeFds[1]; |
| serverPipeFd = pipeFds[0]; |
| Os.fcntlInt(childPipeFd, F_SETFD, 0); |
| fdsToIgnore = new int[]{childPipeFd.getInt$(), serverPipeFd.getInt$()}; |
| } catch (ErrnoException errnoEx) { |
| throw new IllegalStateException("Unable to set up pipe for invoke-with", errnoEx); |
| } |
| } |
| |
| /* |
| * In order to avoid leaking descriptors to the Zygote child, |
| * the native code must close the two Zygote socket descriptors |
| * in the child process before it switches from Zygote-root to |
| * the UID and privileges of the application being launched. |
| * |
| * In order to avoid "bad file descriptor" errors when the |
| * two LocalSocket objects are closed, the Posix file |
| * descriptors are released via a dup2() call which closes |
| * the socket and substitutes an open descriptor to /dev/null. |
| */ |
| |
| int [] fdsToClose = { -1, -1 }; |
| |
| FileDescriptor fd = mSocket.getFileDescriptor(); |
| |
| if (fd != null) { |
| fdsToClose[0] = fd.getInt$(); |
| } |
| |
| fd = zygoteServer.getZygoteSocketFileDescriptor(); |
| |
| if (fd != null) { |
| fdsToClose[1] = fd.getInt$(); |
| } |
| |
| pid = Zygote.forkAndSpecialize(parsedArgs.mUid, parsedArgs.mGid, parsedArgs.mGids, |
| parsedArgs.mRuntimeFlags, rlimits, parsedArgs.mMountExternal, parsedArgs.mSeInfo, |
| parsedArgs.mNiceName, fdsToClose, fdsToIgnore, parsedArgs.mStartChildZygote, |
| parsedArgs.mInstructionSet, parsedArgs.mAppDataDir, parsedArgs.mTargetSdkVersion, |
| parsedArgs.mIsTopApp); |
| |
| try { |
| if (pid == 0) { |
| // in child |
| zygoteServer.setForkChild(); |
| |
| zygoteServer.closeServerSocket(); |
| IoUtils.closeQuietly(serverPipeFd); |
| serverPipeFd = null; |
| |
| return handleChildProc(parsedArgs, childPipeFd, parsedArgs.mStartChildZygote); |
| } else { |
| // In the parent. A pid < 0 indicates a failure and will be handled in |
| // handleParentProc. |
| IoUtils.closeQuietly(childPipeFd); |
| childPipeFd = null; |
| handleParentProc(pid, serverPipeFd); |
| return null; |
| } |
| } finally { |
| IoUtils.closeQuietly(childPipeFd); |
| IoUtils.closeQuietly(serverPipeFd); |
| } |
| } |
| |
| private void handleAbiListQuery() { |
| try { |
| final byte[] abiListBytes = abiList.getBytes(StandardCharsets.US_ASCII); |
| mSocketOutStream.writeInt(abiListBytes.length); |
| mSocketOutStream.write(abiListBytes); |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| } |
| |
| private void handlePidQuery() { |
| try { |
| String pidString = String.valueOf(Process.myPid()); |
| final byte[] pidStringBytes = pidString.getBytes(StandardCharsets.US_ASCII); |
| mSocketOutStream.writeInt(pidStringBytes.length); |
| mSocketOutStream.write(pidStringBytes); |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| } |
| |
| private void handleBootCompleted() { |
| try { |
| mSocketOutStream.writeInt(0); |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| |
| VMRuntime.bootCompleted(); |
| } |
| |
| /** |
| * Preloads resources if the zygote is in lazily preload mode. Writes the result of the |
| * preload operation; {@code 0} when a preload was initiated due to this request and {@code 1} |
| * if no preload was initiated. The latter implies that the zygote is not configured to load |
| * resources lazy or that the zygote has already handled a previous request to handlePreload. |
| */ |
| private void handlePreload() { |
| try { |
| if (isPreloadComplete()) { |
| mSocketOutStream.writeInt(1); |
| } else { |
| preload(); |
| mSocketOutStream.writeInt(0); |
| } |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| } |
| |
| private Runnable stateChangeWithUsapPoolReset(ZygoteServer zygoteServer, |
| Runnable stateChangeCode) { |
| try { |
| if (zygoteServer.isUsapPoolEnabled()) { |
| Log.i(TAG, "Emptying USAP Pool due to state change."); |
| Zygote.emptyUsapPool(); |
| } |
| |
| stateChangeCode.run(); |
| |
| if (zygoteServer.isUsapPoolEnabled()) { |
| Runnable fpResult = |
| zygoteServer.fillUsapPool( |
| new int[]{mSocket.getFileDescriptor().getInt$()}, false); |
| |
| if (fpResult != null) { |
| zygoteServer.setForkChild(); |
| return fpResult; |
| } else { |
| Log.i(TAG, "Finished refilling USAP Pool after state change."); |
| } |
| } |
| |
| mSocketOutStream.writeInt(0); |
| |
| return null; |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| } |
| |
| /** |
| * Makes the necessary changes to implement a new API blacklist exemption policy, and then |
| * responds to the system server, letting it know that the task has been completed. |
| * |
| * This necessitates a change to the internal state of the Zygote. As such, if the USAP |
| * pool is enabled all existing USAPs have an incorrect API blacklist exemption list. To |
| * properly handle this request the pool must be emptied and refilled. This process can return |
| * a Runnable object that must be returned to ZygoteServer.runSelectLoop to be invoked. |
| * |
| * @param zygoteServer The server object that received the request |
| * @param exemptions The new exemption list. |
| * @return A Runnable object representing a new app in any USAPs spawned from here; the |
| * zygote process will always receive a null value from this function. |
| */ |
| private Runnable handleApiBlacklistExemptions(ZygoteServer zygoteServer, String[] exemptions) { |
| return stateChangeWithUsapPoolReset(zygoteServer, |
| () -> ZygoteInit.setApiBlacklistExemptions(exemptions)); |
| } |
| |
| private Runnable handleUsapPoolStatusChange(ZygoteServer zygoteServer, boolean newStatus) { |
| try { |
| Runnable fpResult = zygoteServer.setUsapPoolStatus(newStatus, mSocket); |
| |
| if (fpResult == null) { |
| mSocketOutStream.writeInt(0); |
| } else { |
| zygoteServer.setForkChild(); |
| } |
| |
| return fpResult; |
| } catch (IOException ioe) { |
| throw new IllegalStateException("Error writing to command socket", ioe); |
| } |
| } |
| |
| /** |
| * Changes the API access log sample rate for the Zygote and processes spawned from it. |
| * |
| * This necessitates a change to the internal state of the Zygote. As such, if the USAP |
| * pool is enabled all existing USAPs have an incorrect API access log sample rate. To |
| * properly handle this request the pool must be emptied and refilled. This process can return |
| * a Runnable object that must be returned to ZygoteServer.runSelectLoop to be invoked. |
| * |
| * @param zygoteServer The server object that received the request |
| * @param samplingRate The new sample rate for regular logging |
| * @param statsdSamplingRate The new sample rate for statslog logging |
| * @return A Runnable object representing a new app in any blastulas spawned from here; the |
| * zygote process will always receive a null value from this function. |
| */ |
| private Runnable handleHiddenApiAccessLogSampleRate(ZygoteServer zygoteServer, |
| int samplingRate, int statsdSamplingRate) { |
| return stateChangeWithUsapPoolReset(zygoteServer, () -> { |
| int maxSamplingRate = Math.max(samplingRate, statsdSamplingRate); |
| ZygoteInit.setHiddenApiAccessLogSampleRate(maxSamplingRate); |
| StatsdHiddenApiUsageLogger.setHiddenApiAccessLogSampleRates( |
| samplingRate, statsdSamplingRate); |
| ZygoteInit.setHiddenApiUsageLogger(StatsdHiddenApiUsageLogger.getInstance()); |
| }); |
| } |
| |
| protected void preload() { |
| ZygoteInit.lazyPreload(); |
| } |
| |
| protected boolean isPreloadComplete() { |
| return ZygoteInit.isPreloadComplete(); |
| } |
| |
| protected DataOutputStream getSocketOutputStream() { |
| return mSocketOutStream; |
| } |
| |
| protected void handlePreloadPackage(String packagePath, String libsPath, String libFileName, |
| String cacheKey) { |
| throw new RuntimeException("Zygote does not support package preloading"); |
| } |
| |
| protected boolean canPreloadApp() { |
| return false; |
| } |
| |
| protected void handlePreloadApp(ApplicationInfo aInfo) { |
| throw new RuntimeException("Zygote does not support app preloading"); |
| } |
| |
| /** |
| * Closes socket associated with this connection. |
| */ |
| @UnsupportedAppUsage |
| void closeSocket() { |
| try { |
| mSocket.close(); |
| } catch (IOException ex) { |
| Log.e(TAG, "Exception while closing command " |
| + "socket in parent", ex); |
| } |
| } |
| |
| boolean isClosedByPeer() { |
| return isEof; |
| } |
| |
| /** |
| * Handles post-fork setup of child proc, closing sockets as appropriate, |
| * reopen stdio as appropriate, and ultimately throwing MethodAndArgsCaller |
| * if successful or returning if failed. |
| * |
| * @param parsedArgs non-null; zygote args |
| * @param pipeFd null-ok; pipe for communication back to Zygote. |
| * @param isZygote whether this new child process is itself a new Zygote. |
| */ |
| private Runnable handleChildProc(ZygoteArguments parsedArgs, |
| FileDescriptor pipeFd, boolean isZygote) { |
| /* |
| * By the time we get here, the native code has closed the two actual Zygote |
| * socket connections, and substituted /dev/null in their place. The LocalSocket |
| * objects still need to be closed properly. |
| */ |
| |
| closeSocket(); |
| |
| Zygote.setAppProcessName(parsedArgs, TAG); |
| |
| // End of the postFork event. |
| Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); |
| if (parsedArgs.mInvokeWith != null) { |
| WrapperInit.execApplication(parsedArgs.mInvokeWith, |
| parsedArgs.mNiceName, parsedArgs.mTargetSdkVersion, |
| VMRuntime.getCurrentInstructionSet(), |
| pipeFd, parsedArgs.mRemainingArgs); |
| |
| // Should not get here. |
| throw new IllegalStateException("WrapperInit.execApplication unexpectedly returned"); |
| } else { |
| if (!isZygote) { |
| return ZygoteInit.zygoteInit(parsedArgs.mTargetSdkVersion, |
| parsedArgs.mDisabledCompatChanges, |
| parsedArgs.mRemainingArgs, null /* classLoader */); |
| } else { |
| return ZygoteInit.childZygoteInit(parsedArgs.mTargetSdkVersion, |
| parsedArgs.mRemainingArgs, null /* classLoader */); |
| } |
| } |
| } |
| |
| /** |
| * Handles post-fork cleanup of parent proc |
| * |
| * @param pid != 0; pid of child if > 0 or indication of failed fork |
| * if < 0; |
| * @param pipeFd null-ok; pipe for communication with child. |
| */ |
| private void handleParentProc(int pid, FileDescriptor pipeFd) { |
| if (pid > 0) { |
| setChildPgid(pid); |
| } |
| |
| boolean usingWrapper = false; |
| if (pipeFd != null && pid > 0) { |
| int innerPid = -1; |
| try { |
| // Do a busy loop here. We can't guarantee that a failure (and thus an exception |
| // bail) happens in a timely manner. |
| final int BYTES_REQUIRED = 4; // Bytes in an int. |
| |
| StructPollfd[] fds = new StructPollfd[] { |
| new StructPollfd() |
| }; |
| |
| byte[] data = new byte[BYTES_REQUIRED]; |
| |
| int remainingSleepTime = WRAPPED_PID_TIMEOUT_MILLIS; |
| int dataIndex = 0; |
| long startTime = System.nanoTime(); |
| |
| while (dataIndex < data.length && remainingSleepTime > 0) { |
| fds[0].fd = pipeFd; |
| fds[0].events = (short) POLLIN; |
| fds[0].revents = 0; |
| fds[0].userData = null; |
| |
| int res = android.system.Os.poll(fds, remainingSleepTime); |
| long endTime = System.nanoTime(); |
| int elapsedTimeMs = |
| (int) TimeUnit.MILLISECONDS.convert( |
| endTime - startTime, |
| TimeUnit.NANOSECONDS); |
| remainingSleepTime = WRAPPED_PID_TIMEOUT_MILLIS - elapsedTimeMs; |
| |
| if (res > 0) { |
| if ((fds[0].revents & POLLIN) != 0) { |
| // Only read one byte, so as not to block. |
| int readBytes = android.system.Os.read(pipeFd, data, dataIndex, 1); |
| if (readBytes < 0) { |
| throw new RuntimeException("Some error"); |
| } |
| dataIndex += readBytes; |
| } else { |
| // Error case. revents should contain one of the error bits. |
| break; |
| } |
| } else if (res == 0) { |
| Log.w(TAG, "Timed out waiting for child."); |
| } |
| } |
| |
| if (dataIndex == data.length) { |
| DataInputStream is = new DataInputStream(new ByteArrayInputStream(data)); |
| innerPid = is.readInt(); |
| } |
| |
| if (innerPid == -1) { |
| Log.w(TAG, "Error reading pid from wrapped process, child may have died"); |
| } |
| } catch (Exception ex) { |
| Log.w(TAG, "Error reading pid from wrapped process, child may have died", ex); |
| } |
| |
| // Ensure that the pid reported by the wrapped process is either the |
| // child process that we forked, or a descendant of it. |
| if (innerPid > 0) { |
| int parentPid = innerPid; |
| while (parentPid > 0 && parentPid != pid) { |
| parentPid = Process.getParentPid(parentPid); |
| } |
| if (parentPid > 0) { |
| Log.i(TAG, "Wrapped process has pid " + innerPid); |
| pid = innerPid; |
| usingWrapper = true; |
| } else { |
| Log.w(TAG, "Wrapped process reported a pid that is not a child of " |
| + "the process that we forked: childPid=" + pid |
| + " innerPid=" + innerPid); |
| } |
| } |
| } |
| |
| try { |
| mSocketOutStream.writeInt(pid); |
| mSocketOutStream.writeBoolean(usingWrapper); |
| } catch (IOException ex) { |
| throw new IllegalStateException("Error writing to command socket", ex); |
| } |
| } |
| |
| private void setChildPgid(int pid) { |
| // Try to move the new child into the peer's process group. |
| try { |
| Os.setpgid(pid, Os.getpgid(peer.getPid())); |
| } catch (ErrnoException ex) { |
| // This exception is expected in the case where |
| // the peer is not in our session |
| // TODO get rid of this log message in the case where |
| // getsid(0) != getsid(peer.getPid()) |
| Log.i(TAG, "Zygote: setpgid failed. This is " |
| + "normal if peer is not in our session"); |
| } |
| } |
| } |