JDK14/Java14源码在线阅读
/*
* Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.lang;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.ProcessBuilder.Redirect;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Locale;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import jdk.internal.access.JavaIOFileDescriptorAccess;
import jdk.internal.access.SharedSecrets;
import jdk.internal.ref.CleanerFactory;
import sun.security.action.GetBooleanAction;
import sun.security.action.GetPropertyAction;
/* This class is for the exclusive use of ProcessBuilder.start() to
* create new processes.
*
* @author Martin Buchholz
* @since 1.5
*/
final class ProcessImpl extends Process {
private static final JavaIOFileDescriptorAccess fdAccess
= SharedSecrets.getJavaIOFileDescriptorAccess();
// Windows platforms support a forcible kill signal.
static final boolean SUPPORTS_NORMAL_TERMINATION = false;
/**
* Open a file for writing. If {@code append} is {@code true} then the file
* is opened for atomic append directly and a FileOutputStream constructed
* with the resulting handle. This is because a FileOutputStream created
* to append to a file does not open the file in a manner that guarantees
* that writes by the child process will be atomic.
*/
private static FileOutputStream newFileOutputStream(File f, boolean append)
throws IOException
{
if (append) {
String path = f.getPath();
SecurityManager sm = System.getSecurityManager();
if (sm != null)
sm.checkWrite(path);
long handle = openForAtomicAppend(path);
final FileDescriptor fd = new FileDescriptor();
fdAccess.setHandle(fd, handle);
return AccessController.doPrivileged(
new PrivilegedAction<FileOutputStream>() {
public FileOutputStream run() {
return new FileOutputStream(fd);
}
}
);
} else {
return new FileOutputStream(f);
}
}
// System-dependent portion of ProcessBuilder.start()
static Process start(String cmdarray[],
java.util.Map<String,String> environment,
String dir,
ProcessBuilder.Redirect[] redirects,
boolean redirectErrorStream)
throws IOException
{
String envblock = ProcessEnvironment.toEnvironmentBlock(environment);
FileInputStream f0 = null;
FileOutputStream f1 = null;
FileOutputStream f2 = null;
try {
boolean forceNullOutputStream = false;
long[] stdHandles;
if (redirects == null) {
stdHandles = new long[] { -1L, -1L, -1L };
} else {
stdHandles = new long[3];
if (redirects[0] == Redirect.PIPE) {
stdHandles[0] = -1L;
} else if (redirects[0] == Redirect.INHERIT) {
stdHandles[0] = fdAccess.getHandle(FileDescriptor.in);
} else if (redirects[0] instanceof ProcessBuilder.RedirectPipeImpl) {
stdHandles[0] = fdAccess.getHandle(((ProcessBuilder.RedirectPipeImpl) redirects[0]).getFd());
} else {
f0 = new FileInputStream(redirects[0].file());
stdHandles[0] = fdAccess.getHandle(f0.getFD());
}
if (redirects[1] == Redirect.PIPE) {
stdHandles[1] = -1L;
} else if (redirects[1] == Redirect.INHERIT) {
stdHandles[1] = fdAccess.getHandle(FileDescriptor.out);
} else if (redirects[1] instanceof ProcessBuilder.RedirectPipeImpl) {
stdHandles[1] = fdAccess.getHandle(((ProcessBuilder.RedirectPipeImpl) redirects[1]).getFd());
// Force getInputStream to return a null stream,
// the handle is directly assigned to the next process.
forceNullOutputStream = true;
} else {
f1 = newFileOutputStream(redirects[1].file(),
redirects[1].append());
stdHandles[1] = fdAccess.getHandle(f1.getFD());
}
if (redirects[2] == Redirect.PIPE) {
stdHandles[2] = -1L;
} else if (redirects[2] == Redirect.INHERIT) {
stdHandles[2] = fdAccess.getHandle(FileDescriptor.err);
} else if (redirects[2] instanceof ProcessBuilder.RedirectPipeImpl) {
stdHandles[2] = fdAccess.getHandle(((ProcessBuilder.RedirectPipeImpl) redirects[2]).getFd());
} else {
f2 = newFileOutputStream(redirects[2].file(),
redirects[2].append());
stdHandles[2] = fdAccess.getHandle(f2.getFD());
}
}
Process p = new ProcessImpl(cmdarray, envblock, dir,
stdHandles, forceNullOutputStream, redirectErrorStream);
if (redirects != null) {
// Copy the handles's if they are to be redirected to another process
if (stdHandles[0] >= 0
&& redirects[0] instanceof ProcessBuilder.RedirectPipeImpl) {
fdAccess.setHandle(((ProcessBuilder.RedirectPipeImpl) redirects[0]).getFd(),
stdHandles[0]);
}
if (stdHandles[1] >= 0
&& redirects[1] instanceof ProcessBuilder.RedirectPipeImpl) {
fdAccess.setHandle(((ProcessBuilder.RedirectPipeImpl) redirects[1]).getFd(),
stdHandles[1]);
}
if (stdHandles[2] >= 0
&& redirects[2] instanceof ProcessBuilder.RedirectPipeImpl) {
fdAccess.setHandle(((ProcessBuilder.RedirectPipeImpl) redirects[2]).getFd(),
stdHandles[2]);
}
}
return p;
} finally {
// In theory, close() can throw IOException
// (although it is rather unlikely to happen here)
try { if (f0 != null) f0.close(); }
finally {
try { if (f1 != null) f1.close(); }
finally { if (f2 != null) f2.close(); }
}
}
}
private static class LazyPattern {
// Escape-support version:
// "(\")((?:\\\\\\1|.)+?)\\1|([^\\s\"]+)";
private static final Pattern PATTERN =
Pattern.compile("[^\\s\"]+|\"[^\"]*\"");
};
/* Parses the command string parameter into the executable name and
* program arguments.
*
* The command string is broken into tokens. The token separator is a space
* or quota character. The space inside quotation is not a token separator.
* There are no escape sequences.
*/
private static String[] getTokensFromCommand(String command) {
ArrayList<String> matchList = new ArrayList<>(8);
Matcher regexMatcher = LazyPattern.PATTERN.matcher(command);
while (regexMatcher.find())
matchList.add(regexMatcher.group());
return matchList.toArray(new String[matchList.size()]);
}
private static final int VERIFICATION_CMD_BAT = 0;
private static final int VERIFICATION_WIN32 = 1;
private static final int VERIFICATION_WIN32_SAFE = 2; // inside quotes not allowed
private static final int VERIFICATION_LEGACY = 3;
// See Command shell overview for documentation of special characters.
// https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-xp/bb490954(v=technet.10)
private static final char ESCAPE_VERIFICATION[][] = {
// We guarantee the only command file execution for implicit [cmd.exe] run.
// http://technet.microsoft.com/en-us/library/bb490954.aspx
{' ', '\t', '<', '>', '&', '|', '^'},
{' ', '\t', '<', '>'},
{' ', '\t', '<', '>'},
{' ', '\t'}
};
private static String createCommandLine(int verificationType,
final String executablePath,
final String cmd[])
{
StringBuilder cmdbuf = new StringBuilder(80);
cmdbuf.append(executablePath);
for (int i = 1; i < cmd.length; ++i) {
cmdbuf.append(' ');
String s = cmd[i];
if (needsEscaping(verificationType, s)) {
cmdbuf.append('"');
if (verificationType == VERIFICATION_WIN32_SAFE) {
// Insert the argument, adding '\' to quote any interior quotes
int length = s.length();
for (int j = 0; j < length; j++) {
char c = s.charAt(j);
if (c == DOUBLEQUOTE) {
int count = countLeadingBackslash(verificationType, s, j);
while (count-- > 0) {
cmdbuf.append(BACKSLASH); // double the number of backslashes
}
cmdbuf.append(BACKSLASH); // backslash to quote the quote
}
cmdbuf.append(c);
}
} else {
cmdbuf.append(s);
}
// The code protects the [java.exe] and console command line
// parser, that interprets the [\"] combination as an escape
// sequence for the ["] char.
// http://msdn.microsoft.com/en-us/library/17w5ykft.aspx
//
// If the argument is an FS path, doubling of the tail [\]
// char is not a problem for non-console applications.
//
// The [\"] sequence is not an escape sequence for the [cmd.exe]
// command line parser. The case of the [""] tail escape
// sequence could not be realized due to the argument validation
// procedure.
int count = countLeadingBackslash(verificationType, s, s.length());
while (count-- > 0) {
cmdbuf.append(BACKSLASH); // double the number of backslashes
}
cmdbuf.append('"');
} else {
cmdbuf.append(s);
}
}
return cmdbuf.toString();
}
/**
* Return the argument without quotes (1st and last) if present, else the arg.
* @param str a string
* @return the string without 1st and last quotes
*/
private static String unQuote(String str) {
int len = str.length();
return (len >= 2 && str.charAt(0) == DOUBLEQUOTE && str.charAt(len - 1) == DOUBLEQUOTE)
? str.substring(1, len - 1)
: str;
}
private static boolean needsEscaping(int verificationType, String arg) {
// Switch off MS heuristic for internal ["].
// Please, use the explicit [cmd.exe] call
// if you need the internal ["].
// Example: "cmd.exe", "/C", "Extended_MS_Syntax"
// For [.exe] or [.com] file the unpaired/internal ["]
// in the argument is not a problem.
String unquotedArg = unQuote(arg);
boolean argIsQuoted = !arg.equals(unquotedArg);
boolean embeddedQuote = unquotedArg.indexOf(DOUBLEQUOTE) >= 0;
switch (verificationType) {
case VERIFICATION_CMD_BAT:
if (embeddedQuote) {
throw new IllegalArgumentException("Argument has embedded quote, " +
"use the explicit CMD.EXE call.");
}
break; // break determine whether to quote
case VERIFICATION_WIN32_SAFE:
if (argIsQuoted && embeddedQuote) {
throw new IllegalArgumentException("Malformed argument has embedded quote: "
+ unquotedArg);
}
break;
default:
break;
}
if (!argIsQuoted) {
char testEscape[] = ESCAPE_VERIFICATION[verificationType];
for (int i = 0; i < testEscape.length; ++i) {
if (arg.indexOf(testEscape[i]) >= 0) {
return true;
}
}
}
return false;
}
private static String getExecutablePath(String path)
throws IOException
{
String name = unQuote(path);
if (name.indexOf(DOUBLEQUOTE) >= 0) {
throw new IllegalArgumentException("Executable name has embedded quote, " +
"split the arguments: " + name);
}
// Win32 CreateProcess requires path to be normalized
File fileToRun = new File(name);
// From the [CreateProcess] function documentation:
//
// "If the file name does not contain an extension, .exe is appended.
// Therefore, if the file name extension is .com, this parameter
// must include the .com extension. If the file name ends in
// a period (.) with no extension, or if the file name contains a path,
// .exe is not appended."
//
// "If the file name !does not contain a directory path!,
// the system searches for the executable file in the following
// sequence:..."
//
// In practice ANY non-existent path is extended by [.exe] extension
// in the [CreateProcess] function with the only exception:
// the path ends by (.)
return fileToRun.getPath();
}
/**
* An executable is any program that is an EXE or does not have an extension
* and the Windows createProcess will be looking for .exe.
* The comparison is case insensitive based on the name.
* @param executablePath the executable file
* @return true if the path ends in .exe or does not have an extension.
*/
private boolean isExe(String executablePath) {
File file = new File(executablePath);
String upName = file.getName().toUpperCase(Locale.ROOT);
return (upName.endsWith(".EXE") || upName.indexOf('.') < 0);
}
// Old version that can be bypassed
private boolean isShellFile(String executablePath) {
String upPath = executablePath.toUpperCase();
return (upPath.endsWith(".CMD") || upPath.endsWith(".BAT"));
}
private String quoteString(String arg) {
StringBuilder argbuf = new StringBuilder(arg.length() + 2);
return argbuf.append('"').append(arg).append('"').toString();
}
// Count backslashes before start index of string.
// .bat files don't include backslashes as part of the quote
private static int countLeadingBackslash(int verificationType,
CharSequence input, int start) {
if (verificationType == VERIFICATION_CMD_BAT)
return 0;
int j;
for (j = start - 1; j >= 0 && input.charAt(j) == BACKSLASH; j--) {
// just scanning backwards
}
return (start - 1) - j; // number of BACKSLASHES
}
private static final char DOUBLEQUOTE = '\"';
private static final char BACKSLASH = '\\';
private final long handle;
private final ProcessHandle processHandle;
private OutputStream stdin_stream;
private InputStream stdout_stream;
private InputStream stderr_stream;
private ProcessImpl(String cmd[],
final String envblock,
final String path,
final long[] stdHandles,
boolean forceNullOutputStream,
final boolean redirectErrorStream)
throws IOException
{
String cmdstr;
final SecurityManager security = System.getSecurityManager();
final String value = GetPropertyAction.
privilegedGetProperty("jdk.lang.Process.allowAmbiguousCommands",
(security == null ? "true" : "false"));
final boolean allowAmbiguousCommands = !"false".equalsIgnoreCase(value);
if (allowAmbiguousCommands && security == null) {
// Legacy mode.
// Normalize path if possible.
String executablePath = new File(cmd[0]).getPath();
// No worry about internal, unpaired ["], and redirection/piping.
if (needsEscaping(VERIFICATION_LEGACY, executablePath) )
executablePath = quoteString(executablePath);
cmdstr = createCommandLine(
//legacy mode doesn't worry about extended verification
VERIFICATION_LEGACY,
executablePath,
cmd);
} else {
String executablePath;
try {
executablePath = getExecutablePath(cmd[0]);
} catch (IllegalArgumentException e) {
// Workaround for the calls like
// Runtime.getRuntime().exec("\"C:\\Program Files\\foo\" bar")
// No chance to avoid CMD/BAT injection, except to do the work
// right from the beginning. Otherwise we have too many corner
// cases from
// Runtime.getRuntime().exec(String[] cmd [, ...])
// calls with internal ["] and escape sequences.
// Restore original command line.
StringBuilder join = new StringBuilder();
// terminal space in command line is ok
for (String s : cmd)
join.append(s).append(' ');
// Parse the command line again.
cmd = getTokensFromCommand(join.toString());
executablePath = getExecutablePath(cmd[0]);
// Check new executable name once more
if (security != null)
security.checkExec(executablePath);
}
// Quotation protects from interpretation of the [path] argument as
// start of longer path with spaces. Quotation has no influence to
// [.exe] extension heuristic.
boolean isShell = allowAmbiguousCommands ? isShellFile(executablePath)
: !isExe(executablePath);
cmdstr = createCommandLine(
// We need the extended verification procedures
isShell ? VERIFICATION_CMD_BAT
: (allowAmbiguousCommands ? VERIFICATION_WIN32 : VERIFICATION_WIN32_SAFE),
quoteString(executablePath),
cmd);
}
handle = create(cmdstr, envblock, path,
stdHandles, redirectErrorStream);
// Register a cleaning function to close the handle
final long local_handle = handle; // local to prevent capture of this
CleanerFactory.cleaner().register(this, () -> closeHandle(local_handle));
processHandle = ProcessHandleImpl.getInternal(getProcessId0(handle));
java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction<Void>() {
public Void run() {
if (stdHandles[0] == -1L)
stdin_stream = ProcessBuilder.NullOutputStream.INSTANCE;
else {
FileDescriptor stdin_fd = new FileDescriptor();
fdAccess.setHandle(stdin_fd, stdHandles[0]);
stdin_stream = new BufferedOutputStream(
new FileOutputStream(stdin_fd));
}
if (stdHandles[1] == -1L || forceNullOutputStream)
stdout_stream = ProcessBuilder.NullInputStream.INSTANCE;
else {
FileDescriptor stdout_fd = new FileDescriptor();
fdAccess.setHandle(stdout_fd, stdHandles[1]);
stdout_stream = new BufferedInputStream(
new PipeInputStream(stdout_fd));
}
if (stdHandles[2] == -1L)
stderr_stream = ProcessBuilder.NullInputStream.INSTANCE;
else {
FileDescriptor stderr_fd = new FileDescriptor();
fdAccess.setHandle(stderr_fd, stdHandles[2]);
stderr_stream = new PipeInputStream(stderr_fd);
}
return null; }});
}
public OutputStream getOutputStream() {
return stdin_stream;
}
public InputStream getInputStream() {
return stdout_stream;
}
public InputStream getErrorStream() {
return stderr_stream;
}
private static final int STILL_ACTIVE = getStillActive();
private static native int getStillActive();
public int exitValue() {
int exitCode = getExitCodeProcess(handle);
if (exitCode == STILL_ACTIVE)
throw new IllegalThreadStateException("process has not exited");
return exitCode;
}
private static native int getExitCodeProcess(long handle);
public int waitFor() throws InterruptedException {
waitForInterruptibly(handle);
if (Thread.interrupted())
throw new InterruptedException();
return exitValue();
}
private static native void waitForInterruptibly(long handle);
@Override
public boolean waitFor(long timeout, TimeUnit unit)
throws InterruptedException
{
long remainingNanos = unit.toNanos(timeout); // throw NPE before other conditions
if (getExitCodeProcess(handle) != STILL_ACTIVE) return true;
if (timeout <= 0) return false;
long deadline = System.nanoTime() + remainingNanos;
do {
// Round up to next millisecond
long msTimeout = TimeUnit.NANOSECONDS.toMillis(remainingNanos + 999_999L);
if (msTimeout < 0) {
// if wraps around then wait a long while
msTimeout = Integer.MAX_VALUE;
}
waitForTimeoutInterruptibly(handle, msTimeout);
if (Thread.interrupted())
throw new InterruptedException();
if (getExitCodeProcess(handle) != STILL_ACTIVE) {
return true;
}
remainingNanos = deadline - System.nanoTime();
} while (remainingNanos > 0);
return (getExitCodeProcess(handle) != STILL_ACTIVE);
}
private static native void waitForTimeoutInterruptibly(
long handle, long timeoutMillis);
@Override
public void destroy() {
terminateProcess(handle);
}
@Override
public CompletableFuture<Process> onExit() {
return ProcessHandleImpl.completion(pid(), false)
.handleAsync((exitStatus, unusedThrowable) -> this);
}
@Override
public ProcessHandle toHandle() {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkPermission(new RuntimePermission("manageProcess"));
}
return processHandle;
}
@Override
public boolean supportsNormalTermination() {
return ProcessImpl.SUPPORTS_NORMAL_TERMINATION;
}
@Override
public Process destroyForcibly() {
destroy();
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