| /* |
| * 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 android.net.Credentials; |
| import android.net.LocalSocket; |
| import android.os.Build; |
| import android.os.Process; |
| import android.os.SystemProperties; |
| import android.util.Log; |
| |
| import dalvik.system.PathClassLoader; |
| import dalvik.system.Zygote; |
| |
| import java.io.BufferedReader; |
| import java.io.DataInputStream; |
| import java.io.DataOutputStream; |
| import java.io.FileDescriptor; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.io.PrintStream; |
| import java.util.ArrayList; |
| |
| import libcore.io.ErrnoException; |
| import libcore.io.IoUtils; |
| import libcore.io.Libcore; |
| |
| /** |
| * A connection that can make spawn requests. |
| */ |
| class ZygoteConnection { |
| private static final String TAG = "Zygote"; |
| |
| /** a prototype instance for a future List.toArray() */ |
| private static final int[][] intArray2d = new int[0][0]; |
| |
| /** |
| * {@link android.net.LocalSocket#setSoTimeout} value for connections. |
| * Effectively, the amount of time a requestor has between the start of |
| * the request and the completed request. The select-loop mode Zygote |
| * doesn't have the logic to return to the select loop in the middle of |
| * a request, so we need to time out here to avoid being denial-of-serviced. |
| */ |
| private static final int CONNECTION_TIMEOUT_MILLIS = 1000; |
| |
| /** max number of arguments that a connection can specify */ |
| private static final int MAX_ZYGOTE_ARGC=1024; |
| |
| /** |
| * 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. |
| */ |
| private final LocalSocket mSocket; |
| private final DataOutputStream mSocketOutStream; |
| private final BufferedReader mSocketReader; |
| private final Credentials peer; |
| |
| /** |
| * A long-lived reference to the original command socket used to launch |
| * this peer. If "peer wait" mode is specified, the process that requested |
| * the new VM instance intends to track the lifetime of the spawned instance |
| * via the command socket. In this case, the command socket is closed |
| * in the Zygote and placed here in the spawned instance so that it will |
| * not be collected and finalized. This field remains null at all times |
| * in the original Zygote process, and in all spawned processes where |
| * "peer-wait" mode was not requested. |
| */ |
| private static LocalSocket sPeerWaitSocket = null; |
| |
| /** |
| * Constructs instance from connected socket. |
| * |
| * @param socket non-null; connected socket |
| * @throws IOException |
| */ |
| ZygoteConnection(LocalSocket socket) throws IOException { |
| mSocket = socket; |
| |
| mSocketOutStream |
| = new DataOutputStream(socket.getOutputStream()); |
| |
| mSocketReader = new BufferedReader( |
| new InputStreamReader(socket.getInputStream()), 256); |
| |
| mSocket.setSoTimeout(CONNECTION_TIMEOUT_MILLIS); |
| |
| try { |
| peer = mSocket.getPeerCredentials(); |
| } catch (IOException ex) { |
| Log.e(TAG, "Cannot read peer credentials", ex); |
| throw ex; |
| } |
| } |
| |
| /** |
| * Returns the file descriptor of the associated socket. |
| * |
| * @return null-ok; file descriptor |
| */ |
| FileDescriptor getFileDesciptor() { |
| return mSocket.getFileDescriptor(); |
| } |
| |
| /** |
| * Reads start commands from an open command socket. |
| * Start commands are presently a pair of newline-delimited lines |
| * indicating a) class to invoke main() on b) nice name to set argv[0] to. |
| * Continues to read commands and forkAndSpecialize children until |
| * the socket is closed. This method is used in ZYGOTE_FORK_MODE |
| * |
| * @throws ZygoteInit.MethodAndArgsCaller trampoline to invoke main() |
| * method in child process |
| */ |
| void run() throws ZygoteInit.MethodAndArgsCaller { |
| |
| int loopCount = ZygoteInit.GC_LOOP_COUNT; |
| |
| while (true) { |
| /* |
| * Call gc() before we block in readArgumentList(). |
| * It's work that has to be done anyway, and it's better |
| * to avoid making every child do it. It will also |
| * madvise() any free memory as a side-effect. |
| * |
| * Don't call it every time, because walking the entire |
| * heap is a lot of overhead to free a few hundred bytes. |
| */ |
| if (loopCount <= 0) { |
| ZygoteInit.gc(); |
| loopCount = ZygoteInit.GC_LOOP_COUNT; |
| } else { |
| loopCount--; |
| } |
| |
| if (runOnce()) { |
| break; |
| } |
| } |
| } |
| |
| /** |
| * Reads one start command from the command socket. If successful, |
| * a child is forked and a {@link ZygoteInit.MethodAndArgsCaller} |
| * exception is thrown in that child while in the parent process, |
| * the method returns normally. On failure, the child is not |
| * spawned and messages are printed to the log and stderr. Returns |
| * a boolean status value indicating whether an end-of-file on the command |
| * socket has been encountered. |
| * |
| * @return false if command socket should continue to be read from, or |
| * true if an end-of-file has been encountered. |
| * @throws ZygoteInit.MethodAndArgsCaller trampoline to invoke main() |
| * method in child process |
| */ |
| boolean runOnce() throws ZygoteInit.MethodAndArgsCaller { |
| |
| String args[]; |
| Arguments parsedArgs = null; |
| FileDescriptor[] descriptors; |
| |
| try { |
| args = readArgumentList(); |
| descriptors = mSocket.getAncillaryFileDescriptors(); |
| } catch (IOException ex) { |
| Log.w(TAG, "IOException on command socket " + ex.getMessage()); |
| closeSocket(); |
| return true; |
| } |
| |
| if (args == null) { |
| // EOF reached. |
| closeSocket(); |
| return true; |
| } |
| |
| /** the stderr of the most recent request, if avail */ |
| PrintStream newStderr = null; |
| |
| if (descriptors != null && descriptors.length >= 3) { |
| newStderr = new PrintStream( |
| new FileOutputStream(descriptors[2])); |
| } |
| |
| int pid = -1; |
| FileDescriptor childPipeFd = null; |
| FileDescriptor serverPipeFd = null; |
| |
| try { |
| parsedArgs = new Arguments(args); |
| |
| applyUidSecurityPolicy(parsedArgs, peer); |
| applyRlimitSecurityPolicy(parsedArgs, peer); |
| applyCapabilitiesSecurityPolicy(parsedArgs, peer); |
| applyInvokeWithSecurityPolicy(parsedArgs, peer); |
| |
| applyDebuggerSystemProperty(parsedArgs); |
| applyInvokeWithSystemProperty(parsedArgs); |
| |
| int[][] rlimits = null; |
| |
| if (parsedArgs.rlimits != null) { |
| rlimits = parsedArgs.rlimits.toArray(intArray2d); |
| } |
| |
| if (parsedArgs.runtimeInit && parsedArgs.invokeWith != null) { |
| FileDescriptor[] pipeFds = Libcore.os.pipe(); |
| childPipeFd = pipeFds[1]; |
| serverPipeFd = pipeFds[0]; |
| ZygoteInit.setCloseOnExec(serverPipeFd, true); |
| } |
| |
| pid = Zygote.forkAndSpecialize(parsedArgs.uid, parsedArgs.gid, |
| parsedArgs.gids, parsedArgs.debugFlags, rlimits); |
| } catch (IOException ex) { |
| logAndPrintError(newStderr, "Exception creating pipe", ex); |
| } catch (ErrnoException ex) { |
| logAndPrintError(newStderr, "Exception creating pipe", ex); |
| } catch (IllegalArgumentException ex) { |
| logAndPrintError(newStderr, "Invalid zygote arguments", ex); |
| } catch (ZygoteSecurityException ex) { |
| logAndPrintError(newStderr, |
| "Zygote security policy prevents request: ", ex); |
| } |
| |
| try { |
| if (pid == 0) { |
| // in child |
| IoUtils.closeQuietly(serverPipeFd); |
| serverPipeFd = null; |
| handleChildProc(parsedArgs, descriptors, childPipeFd, newStderr); |
| |
| // should never get here, the child is expected to either |
| // throw ZygoteInit.MethodAndArgsCaller or exec(). |
| return true; |
| } else { |
| // in parent...pid of < 0 means failure |
| IoUtils.closeQuietly(childPipeFd); |
| childPipeFd = null; |
| return handleParentProc(pid, descriptors, serverPipeFd, parsedArgs); |
| } |
| } finally { |
| IoUtils.closeQuietly(childPipeFd); |
| IoUtils.closeQuietly(serverPipeFd); |
| } |
| } |
| |
| /** |
| * Closes socket associated with this connection. |
| */ |
| void closeSocket() { |
| try { |
| mSocket.close(); |
| } catch (IOException ex) { |
| Log.e(TAG, "Exception while closing command " |
| + "socket in parent", ex); |
| } |
| } |
| |
| /** |
| * Handles argument parsing for args related to the zygote spawner. |
| * |
| * Current recognized args: |
| * <ul> |
| * <li> --setuid=<i>uid of child process, defaults to 0</i> |
| * <li> --setgid=<i>gid of child process, defaults to 0</i> |
| * <li> --setgroups=<i>comma-separated list of supplimentary gid's</i> |
| * <li> --capabilities=<i>a pair of comma-separated integer strings |
| * indicating Linux capabilities(2) set for child. The first string |
| * represents the <code>permitted</code> set, and the second the |
| * <code>effective</code> set. Precede each with 0 or |
| * 0x for octal or hexidecimal value. If unspecified, both default to 0. |
| * This parameter is only applied if the uid of the new process will |
| * be non-0. </i> |
| * <li> --rlimit=r,c,m<i>tuple of values for setrlimit() call. |
| * <code>r</code> is the resource, <code>c</code> and <code>m</code> |
| * are the settings for current and max value.</i> |
| * <li> --peer-wait indicates that the command socket should |
| * be inherited by (and set to close-on-exec in) the spawned process |
| * and used to track the lifetime of that process. The spawning process |
| * then exits. Without this flag, it is retained by the spawning process |
| * (and closed in the child) in expectation of a new spawn request. |
| * <li> --classpath=<i>colon-separated classpath</i> indicates |
| * that the specified class (which must b first non-flag argument) should |
| * be loaded from jar files in the specified classpath. Incompatible with |
| * --runtime-init |
| * <li> --runtime-init indicates that the remaining arg list should |
| * be handed off to com.android.internal.os.RuntimeInit, rather than |
| * processed directly |
| * Android runtime startup (eg, Binder initialization) is also eschewed. |
| * <li> --nice-name=<i>nice name to appear in ps</i> |
| * <li> If <code>--runtime-init</code> is present: |
| * [--] <args for RuntimeInit > |
| * <li> If <code>--runtime-init</code> is absent: |
| * [--] <classname> [args...] |
| * </ul> |
| */ |
| static class Arguments { |
| /** from --setuid */ |
| int uid = 0; |
| boolean uidSpecified; |
| |
| /** from --setgid */ |
| int gid = 0; |
| boolean gidSpecified; |
| |
| /** from --setgroups */ |
| int[] gids; |
| |
| /** from --peer-wait */ |
| boolean peerWait; |
| |
| /** |
| * From --enable-debugger, --enable-checkjni, --enable-assert, |
| * --enable-safemode, and --enable-jni-logging. |
| */ |
| int debugFlags; |
| |
| /** from --target-sdk-version. */ |
| int targetSdkVersion; |
| boolean targetSdkVersionSpecified; |
| |
| /** from --classpath */ |
| String classpath; |
| |
| /** from --runtime-init */ |
| boolean runtimeInit; |
| |
| /** from --nice-name */ |
| String niceName; |
| |
| /** from --capabilities */ |
| boolean capabilitiesSpecified; |
| long permittedCapabilities; |
| long effectiveCapabilities; |
| |
| /** from all --rlimit=r,c,m */ |
| ArrayList<int[]> rlimits; |
| |
| /** from --invoke-with */ |
| String invokeWith; |
| |
| /** |
| * Any args after and including the first non-option arg |
| * (or after a '--') |
| */ |
| String remainingArgs[]; |
| |
| /** |
| * Constructs instance and parses args |
| * @param args zygote command-line args |
| * @throws IllegalArgumentException |
| */ |
| Arguments(String args[]) throws IllegalArgumentException { |
| parseArgs(args); |
| } |
| |
| /** |
| * Parses the commandline arguments intended for the Zygote spawner |
| * (such as "--setuid=" and "--setgid=") and creates an array |
| * containing the remaining args. |
| * |
| * Per security review bug #1112214, duplicate args are disallowed in |
| * critical cases to make injection harder. |
| */ |
| private void parseArgs(String args[]) |
| throws IllegalArgumentException { |
| int curArg = 0; |
| |
| for ( /* curArg */ ; curArg < args.length; curArg++) { |
| String arg = args[curArg]; |
| |
| if (arg.equals("--")) { |
| curArg++; |
| break; |
| } else if (arg.startsWith("--setuid=")) { |
| if (uidSpecified) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| uidSpecified = true; |
| uid = Integer.parseInt( |
| arg.substring(arg.indexOf('=') + 1)); |
| } else if (arg.startsWith("--setgid=")) { |
| if (gidSpecified) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| gidSpecified = true; |
| gid = Integer.parseInt( |
| arg.substring(arg.indexOf('=') + 1)); |
| } else if (arg.startsWith("--target-sdk-version=")) { |
| if (targetSdkVersionSpecified) { |
| throw new IllegalArgumentException( |
| "Duplicate target-sdk-version specified"); |
| } |
| targetSdkVersionSpecified = true; |
| targetSdkVersion = Integer.parseInt( |
| arg.substring(arg.indexOf('=') + 1)); |
| } else if (arg.equals("--enable-debugger")) { |
| debugFlags |= Zygote.DEBUG_ENABLE_DEBUGGER; |
| } else if (arg.equals("--enable-safemode")) { |
| debugFlags |= Zygote.DEBUG_ENABLE_SAFEMODE; |
| } else if (arg.equals("--enable-checkjni")) { |
| debugFlags |= Zygote.DEBUG_ENABLE_CHECKJNI; |
| } else if (arg.equals("--enable-jni-logging")) { |
| debugFlags |= Zygote.DEBUG_ENABLE_JNI_LOGGING; |
| } else if (arg.equals("--enable-assert")) { |
| debugFlags |= Zygote.DEBUG_ENABLE_ASSERT; |
| } else if (arg.equals("--peer-wait")) { |
| peerWait = true; |
| } else if (arg.equals("--runtime-init")) { |
| runtimeInit = true; |
| } else if (arg.startsWith("--capabilities=")) { |
| if (capabilitiesSpecified) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| capabilitiesSpecified = true; |
| String capString = arg.substring(arg.indexOf('=')+1); |
| |
| String[] capStrings = capString.split(",", 2); |
| |
| if (capStrings.length == 1) { |
| effectiveCapabilities = Long.decode(capStrings[0]); |
| permittedCapabilities = effectiveCapabilities; |
| } else { |
| permittedCapabilities = Long.decode(capStrings[0]); |
| effectiveCapabilities = Long.decode(capStrings[1]); |
| } |
| } else if (arg.startsWith("--rlimit=")) { |
| // Duplicate --rlimit arguments are specifically allowed. |
| String[] limitStrings |
| = arg.substring(arg.indexOf('=')+1).split(","); |
| |
| if (limitStrings.length != 3) { |
| throw new IllegalArgumentException( |
| "--rlimit= should have 3 comma-delimited ints"); |
| } |
| int[] rlimitTuple = new int[limitStrings.length]; |
| |
| for(int i=0; i < limitStrings.length; i++) { |
| rlimitTuple[i] = Integer.parseInt(limitStrings[i]); |
| } |
| |
| if (rlimits == null) { |
| rlimits = new ArrayList(); |
| } |
| |
| rlimits.add(rlimitTuple); |
| } else if (arg.equals("-classpath")) { |
| if (classpath != null) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| try { |
| classpath = args[++curArg]; |
| } catch (IndexOutOfBoundsException ex) { |
| throw new IllegalArgumentException( |
| "-classpath requires argument"); |
| } |
| } else if (arg.startsWith("--setgroups=")) { |
| if (gids != null) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| |
| String[] params |
| = arg.substring(arg.indexOf('=') + 1).split(","); |
| |
| gids = new int[params.length]; |
| |
| for (int i = params.length - 1; i >= 0 ; i--) { |
| gids[i] = Integer.parseInt(params[i]); |
| } |
| } else if (arg.equals("--invoke-with")) { |
| if (invokeWith != null) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| try { |
| invokeWith = args[++curArg]; |
| } catch (IndexOutOfBoundsException ex) { |
| throw new IllegalArgumentException( |
| "--invoke-with requires argument"); |
| } |
| } else if (arg.startsWith("--nice-name=")) { |
| if (niceName != null) { |
| throw new IllegalArgumentException( |
| "Duplicate arg specified"); |
| } |
| niceName = arg.substring(arg.indexOf('=') + 1); |
| } else { |
| break; |
| } |
| } |
| |
| if (runtimeInit && classpath != null) { |
| throw new IllegalArgumentException( |
| "--runtime-init and -classpath are incompatible"); |
| } |
| |
| remainingArgs = new String[args.length - curArg]; |
| |
| System.arraycopy(args, curArg, remainingArgs, 0, |
| remainingArgs.length); |
| } |
| } |
| |
| /** |
| * Reads an argument list from the command socket/ |
| * @return Argument list or null if EOF is reached |
| * @throws IOException passed straight through |
| */ |
| private String[] readArgumentList() |
| throws IOException { |
| |
| /** |
| * See android.os.Process.zygoteSendArgsAndGetPid() |
| * Presently the wire format to the zygote process is: |
| * a) a count of arguments (argc, in essence) |
| * b) a number of newline-separated argument strings equal to count |
| * |
| * After the zygote process reads these it will write the pid of |
| * the child or -1 on failure. |
| */ |
| |
| int argc; |
| |
| try { |
| String s = mSocketReader.readLine(); |
| |
| if (s == null) { |
| // EOF reached. |
| return null; |
| } |
| argc = Integer.parseInt(s); |
| } catch (NumberFormatException ex) { |
| Log.e(TAG, "invalid Zygote wire format: non-int at argc"); |
| throw new IOException("invalid wire format"); |
| } |
| |
| // See bug 1092107: large argc can be used for a DOS attack |
| if (argc > MAX_ZYGOTE_ARGC) { |
| throw new IOException("max arg count exceeded"); |
| } |
| |
| String[] result = new String[argc]; |
| for (int i = 0; i < argc; i++) { |
| result[i] = mSocketReader.readLine(); |
| if (result[i] == null) { |
| // We got an unexpected EOF. |
| throw new IOException("truncated request"); |
| } |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Applies zygote security policy per bugs #875058 and #1082165. |
| * Based on the credentials of the process issuing a zygote command: |
| * <ol> |
| * <li> uid 0 (root) may specify any uid, gid, and setgroups() list |
| * <li> uid 1000 (Process.SYSTEM_UID) may specify any uid > 1000 in normal |
| * operation. It may also specify any gid and setgroups() list it chooses. |
| * In factory test mode, it may specify any UID. |
| * <li> Any other uid may not specify any uid, gid, or setgroups list. The |
| * uid and gid will be inherited from the requesting process. |
| * </ul> |
| * |
| * @param args non-null; zygote spawner arguments |
| * @param peer non-null; peer credentials |
| * @throws ZygoteSecurityException |
| */ |
| private static void applyUidSecurityPolicy(Arguments args, Credentials peer) |
| throws ZygoteSecurityException { |
| |
| int peerUid = peer.getUid(); |
| |
| if (peerUid == 0) { |
| // Root can do what it wants |
| } else if (peerUid == Process.SYSTEM_UID ) { |
| // System UID is restricted, except in factory test mode |
| String factoryTest = SystemProperties.get("ro.factorytest"); |
| boolean uidRestricted; |
| |
| /* In normal operation, SYSTEM_UID can only specify a restricted |
| * set of UIDs. In factory test mode, SYSTEM_UID may specify any uid. |
| */ |
| uidRestricted |
| = !(factoryTest.equals("1") || factoryTest.equals("2")); |
| |
| if (uidRestricted |
| && args.uidSpecified && (args.uid < Process.SYSTEM_UID)) { |
| throw new ZygoteSecurityException( |
| "System UID may not launch process with UID < " |
| + Process.SYSTEM_UID); |
| } |
| } else { |
| // Everything else |
| if (args.uidSpecified || args.gidSpecified |
| || args.gids != null) { |
| throw new ZygoteSecurityException( |
| "App UIDs may not specify uid's or gid's"); |
| } |
| } |
| |
| // If not otherwise specified, uid and gid are inherited from peer |
| if (!args.uidSpecified) { |
| args.uid = peer.getUid(); |
| args.uidSpecified = true; |
| } |
| if (!args.gidSpecified) { |
| args.gid = peer.getGid(); |
| args.gidSpecified = true; |
| } |
| } |
| |
| |
| /** |
| * Applies debugger system properties to the zygote arguments. |
| * |
| * If "ro.debuggable" is "1", all apps are debuggable. Otherwise, |
| * the debugger state is specified via the "--enable-debugger" flag |
| * in the spawn request. |
| * |
| * @param args non-null; zygote spawner args |
| */ |
| public static void applyDebuggerSystemProperty(Arguments args) { |
| if ("1".equals(SystemProperties.get("ro.debuggable"))) { |
| args.debugFlags |= Zygote.DEBUG_ENABLE_DEBUGGER; |
| } |
| } |
| |
| /** |
| * Applies zygote security policy per bug #1042973. Based on the credentials |
| * of the process issuing a zygote command: |
| * <ol> |
| * <li> peers of uid 0 (root) and uid 1000 (Process.SYSTEM_UID) |
| * may specify any rlimits. |
| * <li> All other uids may not specify rlimits. |
| * </ul> |
| * @param args non-null; zygote spawner arguments |
| * @param peer non-null; peer credentials |
| * @throws ZygoteSecurityException |
| */ |
| private static void applyRlimitSecurityPolicy( |
| Arguments args, Credentials peer) |
| throws ZygoteSecurityException { |
| |
| int peerUid = peer.getUid(); |
| |
| if (!(peerUid == 0 || peerUid == Process.SYSTEM_UID)) { |
| // All peers with UID other than root or SYSTEM_UID |
| if (args.rlimits != null) { |
| throw new ZygoteSecurityException( |
| "This UID may not specify rlimits."); |
| } |
| } |
| } |
| |
| /** |
| * Applies zygote security policy per bug #1042973. A root peer may |
| * spawn an instance with any capabilities. All other uids may spawn |
| * instances with any of the capabilities in the peer's permitted set |
| * but no more. |
| * |
| * @param args non-null; zygote spawner arguments |
| * @param peer non-null; peer credentials |
| * @throws ZygoteSecurityException |
| */ |
| private static void applyCapabilitiesSecurityPolicy( |
| Arguments args, Credentials peer) |
| throws ZygoteSecurityException { |
| |
| if (args.permittedCapabilities == 0 |
| && args.effectiveCapabilities == 0) { |
| // nothing to check |
| return; |
| } |
| |
| if (peer.getUid() == 0) { |
| // root may specify anything |
| return; |
| } |
| |
| long permittedCaps; |
| |
| try { |
| permittedCaps = ZygoteInit.capgetPermitted(peer.getPid()); |
| } catch (IOException ex) { |
| throw new ZygoteSecurityException( |
| "Error retrieving peer's capabilities."); |
| } |
| |
| /* |
| * Ensure that the client did not specify an effective set larger |
| * than the permitted set. The kernel will enforce this too, but we |
| * do it here to make the following check easier. |
| */ |
| if (((~args.permittedCapabilities) & args.effectiveCapabilities) != 0) { |
| throw new ZygoteSecurityException( |
| "Effective capabilities cannot be superset of " |
| + " permitted capabilities" ); |
| } |
| |
| /* |
| * Ensure that the new permitted (and thus the new effective) set is |
| * a subset of the peer process's permitted set |
| */ |
| |
| if (((~permittedCaps) & args.permittedCapabilities) != 0) { |
| throw new ZygoteSecurityException( |
| "Peer specified unpermitted capabilities" ); |
| } |
| } |
| |
| /** |
| * Applies zygote security policy. |
| * Based on the credentials of the process issuing a zygote command: |
| * <ol> |
| * <li> uid 0 (root) may specify --invoke-with to launch Zygote with a |
| * wrapper command. |
| * <li> Any other uid may not specify any invoke-with argument. |
| * </ul> |
| * |
| * @param args non-null; zygote spawner arguments |
| * @param peer non-null; peer credentials |
| * @throws ZygoteSecurityException |
| */ |
| private static void applyInvokeWithSecurityPolicy(Arguments args, Credentials peer) |
| throws ZygoteSecurityException { |
| int peerUid = peer.getUid(); |
| |
| if (args.invokeWith != null && peerUid != 0) { |
| throw new ZygoteSecurityException("Peer is not permitted to specify " |
| + "an explicit invoke-with wrapper command"); |
| } |
| } |
| |
| /** |
| * Applies invoke-with system properties to the zygote arguments. |
| * |
| * @param parsedArgs non-null; zygote args |
| */ |
| public static void applyInvokeWithSystemProperty(Arguments args) { |
| if (args.invokeWith == null && args.niceName != null) { |
| if (args.niceName != null) { |
| String property = "wrap." + args.niceName; |
| if (property.length() > 31) { |
| property = property.substring(0, 31); |
| } |
| args.invokeWith = SystemProperties.get(property); |
| if (args.invokeWith != null && args.invokeWith.length() == 0) { |
| args.invokeWith = null; |
| } |
| } |
| } |
| } |
| |
| /** |
| * 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 descriptors null-ok; new file descriptors for stdio if available. |
| * @param pipeFd null-ok; pipe for communication back to Zygote. |
| * @param newStderr null-ok; stream to use for stderr until stdio |
| * is reopened. |
| * |
| * @throws ZygoteInit.MethodAndArgsCaller on success to |
| * trampoline to code that invokes static main. |
| */ |
| private void handleChildProc(Arguments parsedArgs, |
| FileDescriptor[] descriptors, FileDescriptor pipeFd, PrintStream newStderr) |
| throws ZygoteInit.MethodAndArgsCaller { |
| |
| /* |
| * Close the socket, unless we're in "peer wait" mode, in which |
| * case it's used to track the liveness of this process. |
| */ |
| |
| if (parsedArgs.peerWait) { |
| try { |
| ZygoteInit.setCloseOnExec(mSocket.getFileDescriptor(), true); |
| sPeerWaitSocket = mSocket; |
| } catch (IOException ex) { |
| Log.e(TAG, "Zygote Child: error setting peer wait " |
| + "socket to be close-on-exec", ex); |
| } |
| } else { |
| closeSocket(); |
| ZygoteInit.closeServerSocket(); |
| } |
| |
| if (descriptors != null) { |
| try { |
| ZygoteInit.reopenStdio(descriptors[0], |
| descriptors[1], descriptors[2]); |
| |
| for (FileDescriptor fd: descriptors) { |
| IoUtils.closeQuietly(fd); |
| } |
| newStderr = System.err; |
| } catch (IOException ex) { |
| Log.e(TAG, "Error reopening stdio", ex); |
| } |
| } |
| |
| if (parsedArgs.niceName != null) { |
| Process.setArgV0(parsedArgs.niceName); |
| } |
| |
| if (parsedArgs.runtimeInit) { |
| if (parsedArgs.invokeWith != null) { |
| WrapperInit.execApplication(parsedArgs.invokeWith, |
| parsedArgs.niceName, parsedArgs.targetSdkVersion, |
| pipeFd, parsedArgs.remainingArgs); |
| } else { |
| RuntimeInit.zygoteInit(parsedArgs.targetSdkVersion, |
| parsedArgs.remainingArgs); |
| } |
| } else { |
| String className; |
| try { |
| className = parsedArgs.remainingArgs[0]; |
| } catch (ArrayIndexOutOfBoundsException ex) { |
| logAndPrintError(newStderr, |
| "Missing required class name argument", null); |
| return; |
| } |
| |
| String[] mainArgs = new String[parsedArgs.remainingArgs.length - 1]; |
| System.arraycopy(parsedArgs.remainingArgs, 1, |
| mainArgs, 0, mainArgs.length); |
| |
| if (parsedArgs.invokeWith != null) { |
| WrapperInit.execStandalone(parsedArgs.invokeWith, |
| parsedArgs.classpath, className, mainArgs); |
| } else { |
| ClassLoader cloader; |
| if (parsedArgs.classpath != null) { |
| cloader = new PathClassLoader(parsedArgs.classpath, |
| ClassLoader.getSystemClassLoader()); |
| } else { |
| cloader = ClassLoader.getSystemClassLoader(); |
| } |
| |
| try { |
| ZygoteInit.invokeStaticMain(cloader, className, mainArgs); |
| } catch (RuntimeException ex) { |
| logAndPrintError(newStderr, "Error starting.", ex); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Handles post-fork cleanup of parent proc |
| * |
| * @param pid != 0; pid of child if > 0 or indication of failed fork |
| * if < 0; |
| * @param descriptors null-ok; file descriptors for child's new stdio if |
| * specified. |
| * @param pipeFd null-ok; pipe for communication with child. |
| * @param parsedArgs non-null; zygote args |
| * @return true for "exit command loop" and false for "continue command |
| * loop" |
| */ |
| private boolean handleParentProc(int pid, |
| FileDescriptor[] descriptors, FileDescriptor pipeFd, Arguments parsedArgs) { |
| |
| if (pid > 0) { |
| setChildPgid(pid); |
| } |
| |
| if (descriptors != null) { |
| for (FileDescriptor fd: descriptors) { |
| IoUtils.closeQuietly(fd); |
| } |
| } |
| |
| if (pipeFd != null && pid > 0) { |
| DataInputStream is = new DataInputStream(new FileInputStream(pipeFd)); |
| int innerPid = -1; |
| try { |
| innerPid = is.readInt(); |
| } catch (IOException ex) { |
| Log.w(TAG, "Error reading pid from wrapped process, child may have died", ex); |
| } finally { |
| try { |
| is.close(); |
| } catch (IOException 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; |
| } 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); |
| } catch (IOException ex) { |
| Log.e(TAG, "Error reading from command socket", ex); |
| return true; |
| } |
| |
| /* |
| * If the peer wants to use the socket to wait on the |
| * newly spawned process, then we're all done. |
| */ |
| if (parsedArgs.peerWait) { |
| try { |
| mSocket.close(); |
| } catch (IOException ex) { |
| Log.e(TAG, "Zygote: error closing sockets", ex); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| private void setChildPgid(int pid) { |
| // Try to move the new child into the peer's process group. |
| try { |
| ZygoteInit.setpgid(pid, ZygoteInit.getpgid(peer.getPid())); |
| } catch (IOException 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"); |
| } |
| } |
| |
| /** |
| * Logs an error message and prints it to the specified stream, if |
| * provided |
| * |
| * @param newStderr null-ok; a standard error stream |
| * @param message non-null; error message |
| * @param ex null-ok an exception |
| */ |
| private static void logAndPrintError (PrintStream newStderr, |
| String message, Throwable ex) { |
| Log.e(TAG, message, ex); |
| if (newStderr != null) { |
| newStderr.println(message + (ex == null ? "" : ex)); |
| } |
| } |
| } |