Use system property to detect if root is running the program
Motivation: We forked a new process to detect if the program is run by root. We should better just use user.name system property Modifications: - Change PlatformDependent.isRoot0() to read the user.name system property to detect if root runs the program and rename it to maybeSuperUser0(). - Rename PlatformDependent.isRoot() to maybeSuperUser() and let it init directly in the static block Result: Less heavy way to detect if the program is run by root.
This commit is contained in:
Norman Maurer
parent
c6a3cae269
commit
9ade81ab5b
@ -15,7 +15,6 @@
|
||||
*/
|
||||
package io.netty.util.internal;
|
||||
|
||||
import io.netty.util.CharsetUtil;
|
||||
import io.netty.util.internal.logging.InternalLogger;
|
||||
import io.netty.util.internal.logging.InternalLoggerFactory;
|
||||
import org.jctools.queues.MpscArrayQueue;
|
||||
@ -27,13 +26,8 @@ import org.jctools.queues.atomic.SpscLinkedAtomicQueue;
|
||||
import org.jctools.util.Pow2;
|
||||
import org.jctools.util.UnsafeAccess;
|
||||
|
||||
import java.io.BufferedReader;
|
||||
import java.io.File;
|
||||
import java.io.IOException;
|
||||
import java.io.InputStreamReader;
|
||||
import java.lang.reflect.Method;
|
||||
import java.net.InetSocketAddress;
|
||||
import java.net.ServerSocket;
|
||||
import java.nio.ByteBuffer;
|
||||
import java.nio.ByteOrder;
|
||||
import java.security.AccessController;
|
||||
@ -78,7 +72,7 @@ public final class PlatformDependent {
|
||||
|
||||
private static final boolean IS_ANDROID = isAndroid0();
|
||||
private static final boolean IS_WINDOWS = isWindows0();
|
||||
private static volatile Boolean IS_ROOT;
|
||||
private static final boolean MAYBE_SUPER_USER;
|
||||
|
||||
private static final int JAVA_VERSION = javaVersion0();
|
||||
|
||||
@ -162,6 +156,8 @@ public final class PlatformDependent {
|
||||
}
|
||||
DIRECT_MEMORY_LIMIT = maxDirectMemory;
|
||||
logger.debug("io.netty.maxDirectMemory: {} bytes", maxDirectMemory);
|
||||
|
||||
MAYBE_SUPER_USER = maybeSuperUser0();
|
||||
}
|
||||
|
||||
/**
|
||||
@ -179,18 +175,11 @@ public final class PlatformDependent {
|
||||
}
|
||||
|
||||
/**
|
||||
* Return {@code true} if the current user is root. Note that this method returns
|
||||
* {@code false} if on Windows.
|
||||
* Return {@code true} if the current user may be a super-user. Be aware that this is just an hint and so it may
|
||||
* return false-positives.
|
||||
*/
|
||||
public static boolean isRoot() {
|
||||
if (IS_ROOT == null) {
|
||||
synchronized (PlatformDependent.class) {
|
||||
if (IS_ROOT == null) {
|
||||
IS_ROOT = isRoot0();
|
||||
}
|
||||
}
|
||||
}
|
||||
return IS_ROOT;
|
||||
public static boolean maybeSuperUser() {
|
||||
return MAYBE_SUPER_USER;
|
||||
}
|
||||
|
||||
/**
|
||||
@ -902,97 +891,13 @@ public final class PlatformDependent {
|
||||
return windows;
|
||||
}
|
||||
|
||||
private static boolean isRoot0() {
|
||||
private static boolean maybeSuperUser0() {
|
||||
String username = SystemPropertyUtil.get("user.name");
|
||||
if (isWindows()) {
|
||||
return false;
|
||||
return "Administrator".equals(username);
|
||||
}
|
||||
|
||||
String[] ID_COMMANDS = { "/usr/bin/id", "/bin/id", "/usr/xpg4/bin/id", "id"};
|
||||
Pattern UID_PATTERN = Pattern.compile("^(?:0|[1-9][0-9]*)$");
|
||||
for (String idCmd: ID_COMMANDS) {
|
||||
Process p = null;
|
||||
BufferedReader in = null;
|
||||
String uid = null;
|
||||
try {
|
||||
p = Runtime.getRuntime().exec(new String[] { idCmd, "-u" });
|
||||
in = new BufferedReader(new InputStreamReader(p.getInputStream(), CharsetUtil.US_ASCII));
|
||||
uid = in.readLine();
|
||||
in.close();
|
||||
|
||||
for (;;) {
|
||||
try {
|
||||
int exitCode = p.waitFor();
|
||||
if (exitCode != 0) {
|
||||
uid = null;
|
||||
}
|
||||
break;
|
||||
} catch (InterruptedException e) {
|
||||
// Ignore
|
||||
}
|
||||
}
|
||||
} catch (Throwable ignored) {
|
||||
// Failed to run the command.
|
||||
uid = null;
|
||||
} finally {
|
||||
if (in != null) {
|
||||
try {
|
||||
in.close();
|
||||
} catch (IOException e) {
|
||||
// Ignore
|
||||
}
|
||||
}
|
||||
if (p != null) {
|
||||
try {
|
||||
p.destroy();
|
||||
} catch (Exception e) {
|
||||
// Android sometimes triggers an ErrnoException.
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (uid != null && UID_PATTERN.matcher(uid).matches()) {
|
||||
logger.debug("UID: {}", uid);
|
||||
return "0".equals(uid);
|
||||
}
|
||||
}
|
||||
|
||||
logger.debug("Could not determine the current UID using /usr/bin/id; attempting to bind at privileged ports.");
|
||||
|
||||
Pattern PERMISSION_DENIED = Pattern.compile(".*(?:denied|not.*permitted).*");
|
||||
for (int i = 1023; i > 0; i --) {
|
||||
ServerSocket ss = null;
|
||||
try {
|
||||
ss = new ServerSocket();
|
||||
ss.setReuseAddress(true);
|
||||
ss.bind(new InetSocketAddress(i));
|
||||
if (logger.isDebugEnabled()) {
|
||||
logger.debug("UID: 0 (succeded to bind at port {})", i);
|
||||
}
|
||||
return true;
|
||||
} catch (Exception e) {
|
||||
// Failed to bind.
|
||||
// Check the error message so that we don't always need to bind 1023 times.
|
||||
String message = e.getMessage();
|
||||
if (message == null) {
|
||||
message = "";
|
||||
}
|
||||
message = message.toLowerCase();
|
||||
if (PERMISSION_DENIED.matcher(message).matches()) {
|
||||
break;
|
||||
}
|
||||
} finally {
|
||||
if (ss != null) {
|
||||
try {
|
||||
ss.close();
|
||||
} catch (Exception e) {
|
||||
// Ignore.
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
logger.debug("UID: non-root (failed to bind at any privileged ports)");
|
||||
return false;
|
||||
// Check for root and toor as some BSDs have a toor user that is basically the same as root.
|
||||
return "root".equals(username) || "toor".equals(username);
|
||||
}
|
||||
|
||||
private static int javaVersion0() {
|
||||
|
||||
@ -540,7 +540,7 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
|
||||
if (Boolean.TRUE.equals(config().getOption(ChannelOption.SO_BROADCAST)) &&
|
||||
localAddress instanceof InetSocketAddress &&
|
||||
!((InetSocketAddress) localAddress).getAddress().isAnyLocalAddress() &&
|
||||
!PlatformDependent.isWindows() && !PlatformDependent.isRoot()) {
|
||||
!PlatformDependent.isWindows() && !PlatformDependent.maybeSuperUser()) {
|
||||
// Warn a user about the fact that a non-root user can't receive a
|
||||
// broadcast packet on *nix if the socket is bound on non-wildcard address.
|
||||
logger.warn(
|
||||
|
||||
@ -157,7 +157,7 @@ public class DefaultDatagramChannelConfig extends DefaultChannelConfig implement
|
||||
// See: https://github.com/netty/netty/issues/576
|
||||
if (broadcast &&
|
||||
!javaSocket.getLocalAddress().isAnyLocalAddress() &&
|
||||
!PlatformDependent.isWindows() && !PlatformDependent.isRoot()) {
|
||||
!PlatformDependent.isWindows() && !PlatformDependent.maybeSuperUser()) {
|
||||
// Warn a user about the fact that a non-root user can't receive a
|
||||
// broadcast packet on *nix if the socket is bound on non-wildcard address.
|
||||
logger.warn(
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user