8245194: Unix domain socket channel implementation

Reviewed-by: erikj, dfuchs, alanb, chegar

src/java.base/windows/classes/sun/nio/ch/PipeImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2020, 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
@@ -31,8 +31,14 @@ package sun.nio.ch;
 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
+import java.net.SocketAddress;
+import java.net.UnixDomainSocketAddress;
+import java.net.StandardProtocolFamily;
+import java.net.StandardSocketOptions;
 import java.nio.*;
 import java.nio.channels.*;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.channels.spi.*;
 import java.security.AccessController;
 import java.security.PrivilegedExceptionAction;
@@ -55,16 +61,17 @@ class PipeImpl
     private static final Random RANDOM_NUMBER_GENERATOR = new SecureRandom();
 
     // Source and sink channels
-    private SourceChannel source;
-    private SinkChannel sink;
+    private final SourceChannel source;
+    private final SinkChannel sink;
 
     private class Initializer
         implements PrivilegedExceptionAction<Void>
     {
 
         private final SelectorProvider sp;
-
-        private IOException ioe = null;
+        private IOException ioe;
+        SourceChannelImpl source;
+        SinkChannelImpl sink;
 
         private Initializer(SelectorProvider sp) {
             this.sp = sp;
@@ -103,23 +110,20 @@ class PipeImpl
                 ServerSocketChannel ssc = null;
                 SocketChannel sc1 = null;
                 SocketChannel sc2 = null;
+                // Loopback address
+                SocketAddress sa = null;
 
                 try {
                     // Create secret with a backing array.
                     ByteBuffer secret = ByteBuffer.allocate(NUM_SECRET_BYTES);
                     ByteBuffer bb = ByteBuffer.allocate(NUM_SECRET_BYTES);
 
-                    // Loopback address
-                    InetAddress lb = InetAddress.getLoopbackAddress();
-                    assert(lb.isLoopbackAddress());
-                    InetSocketAddress sa = null;
                     for(;;) {
                         // Bind ServerSocketChannel to a port on the loopback
                         // address
                         if (ssc == null || !ssc.isOpen()) {
-                            ssc = ServerSocketChannel.open();
-                            ssc.socket().bind(new InetSocketAddress(lb, 0));
-                            sa = new InetSocketAddress(lb, ssc.socket().getLocalPort());
+                            ssc = createListener();
+                            sa = ssc.getLocalAddress();
                         }
 
                         // Establish connection (assume connections are eagerly
@@ -160,18 +164,43 @@ class PipeImpl
                     try {
                         if (ssc != null)
                             ssc.close();
+                        if (sa instanceof UnixDomainSocketAddress) {
+                            Path path = ((UnixDomainSocketAddress) sa).getPath();
+                            Files.deleteIfExists(path);
+                        }
                     } catch (IOException e2) {}
                 }
             }
         }
     }
 
-    PipeImpl(final SelectorProvider sp) throws IOException {
+    /**
+     * Creates a Pipe implementation that supports buffering.
+     */
+    PipeImpl(SelectorProvider sp) throws IOException {
+        this(sp, true);
+    }
+
+    /**
+     * Creates Pipe implementation that supports optionally buffering.
+     *
+     * @implNote The pipe uses Unix domain sockets where possible. It uses a
+     * loopback connection on older editions of Windows. When buffering is
+     * disabled then it sets TCP_NODELAY on the sink channel.
+     */
+    PipeImpl(SelectorProvider sp, boolean buffering) throws IOException {
+        Initializer initializer = new Initializer(sp);
         try {
-            AccessController.doPrivileged(new Initializer(sp));
-        } catch (PrivilegedActionException x) {
-            throw (IOException)x.getCause();
+            AccessController.doPrivileged(initializer);
+            SinkChannelImpl sink = initializer.sink;
+            if (sink.isNetSocket() && !buffering) {
+                sink.setOption(StandardSocketOptions.TCP_NODELAY, true);
+            }
+        } catch (PrivilegedActionException pae) {
+            throw (IOException) pae.getCause();
         }
+        this.source = initializer.source;
+        this.sink = initializer.sink;
     }
 
     public SourceChannel source() {
@@ -182,4 +211,25 @@ class PipeImpl
         return sink;
     }
 
+    private static volatile boolean noUnixDomainSockets;
+
+    private static ServerSocketChannel createListener() throws IOException {
+        ServerSocketChannel listener = null;
+        if (!noUnixDomainSockets) {
+            try {
+                listener = ServerSocketChannel.open(StandardProtocolFamily.UNIX);
+                return listener.bind(null);
+            } catch (UnsupportedOperationException | IOException e) {
+                // IOException is most likely to be caused by the temporary directory
+                // name being too long. Possibly should log this.
+                noUnixDomainSockets = true;
+                if (listener != null)
+                    listener.close();
+            }
+        }
+        listener = ServerSocketChannel.open();
+        InetAddress lb = InetAddress.getLoopbackAddress();
+        listener.bind(new InetSocketAddress(lb, 0));
+        return listener;
+    }
 }

src/java.base/windows/classes/sun/nio/ch/SinkChannelImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2020, 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
@@ -30,6 +30,7 @@ package sun.nio.ch;
 
 import java.io.IOException;
 import java.io.FileDescriptor;
+import java.net.SocketOption;
 import java.nio.ByteBuffer;
 import java.nio.channels.*;
 import java.nio.channels.spi.*;
@@ -44,19 +45,27 @@ class SinkChannelImpl
     implements SelChImpl
 {
     // The SocketChannel assoicated with this pipe
-    final SocketChannel sc;
+    private final SocketChannelImpl sc;
 
     public FileDescriptor getFD() {
-        return ((SocketChannelImpl)sc).getFD();
+        return sc.getFD();
     }
 
     public int getFDVal() {
-        return ((SocketChannelImpl)sc).getFDVal();
+        return sc.getFDVal();
     }
 
     SinkChannelImpl(SelectorProvider sp, SocketChannel sc) {
         super(sp);
-        this.sc = sc;
+        this.sc = (SocketChannelImpl) sc;
+    }
+
+    boolean isNetSocket() {
+        return sc.isNetSocket();
+    }
+
+    <T> void setOption(SocketOption<T> name, T value) throws IOException {
+        sc.setOption(name, value);
     }
 
     protected void implCloseSelectableChannel() throws IOException {

src/java.base/windows/classes/sun/nio/ch/UnixDomainSocketsUtil.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2002, 2018, 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.nio.ch;
+
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import sun.net.NetProperties;
+import jdk.internal.util.StaticProperty;
+
+class UnixDomainSocketsUtil {
+    private UnixDomainSocketsUtil() { }
+
+    static Charset getCharset() {
+        return StandardCharsets.UTF_8;
+    }
+
+    /**
+     * Return the temp directory for storing automatically bound
+     * server sockets.
+     *
+     * On Windows we search the following directories in sequence:
+     *
+     * 1. ${jdk.net.unixdomain.tmpdir} if set as system property
+     * 2. ${jdk.net.unixdomain.tmpdir} if set as net property
+     * 3. %TEMP%
+     * 4. ${java.io.tmpdir}
+     */
+    static String getTempDir() {
+        PrivilegedAction<String> action = () -> {
+            String s = NetProperties.get("jdk.net.unixdomain.tmpdir");
+            if (s != null) {
+                return s;
+            }
+            String temp = System.getenv("TEMP");
+            if (temp != null) {
+                return temp;
+            }
+            return StaticProperty.javaIoTmpDir();
+        };
+        return AccessController.doPrivileged(action);
+    }
+}
+

src/java.base/windows/classes/sun/nio/ch/WindowsSelectorImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2020, 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
@@ -30,6 +30,7 @@ import java.nio.channels.ClosedSelectorException;
 import java.nio.channels.Pipe;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.Selector;
+import java.nio.channels.SelectableChannel;
 import java.nio.channels.spi.SelectorProvider;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
@@ -139,14 +140,9 @@ class WindowsSelectorImpl extends SelectorImpl {
     WindowsSelectorImpl(SelectorProvider sp) throws IOException {
         super(sp);
         pollWrapper = new PollArrayWrapper(INIT_CAP);
-        wakeupPipe = Pipe.open();
+        wakeupPipe = new PipeImpl(sp, false);
         wakeupSourceFd = ((SelChImpl)wakeupPipe.source()).getFDVal();
-
-        // Disable the Nagle algorithm so that the wakeup is more immediate
-        SinkChannelImpl sink = (SinkChannelImpl)wakeupPipe.sink();
-        (sink.sc).socket().setTcpNoDelay(true);
-        wakeupSinkFd = ((SelChImpl)sink).getFDVal();
-
+        wakeupSinkFd = ((SelChImpl)wakeupPipe.sink()).getFDVal();
         pollWrapper.addWakeupSocket(wakeupSourceFd, 0);
     }
 
@@ -413,19 +409,19 @@ class WindowsSelectorImpl extends SelectorImpl {
                 // processDeregisterQueue.
                 if (me == null)
                     continue;
-                SelectionKeyImpl sk = me.ski;
+                SelectionKeyImpl ski = me.ski;
 
                 // The descriptor may be in the exceptfds set because there is
                 // OOB data queued to the socket. If there is OOB data then it
                 // is discarded and the key is not added to the selected set.
-                if (isExceptFds &&
-                    (sk.channel() instanceof SocketChannelImpl) &&
-                    discardUrgentData(desc))
-                {
+                SelectableChannel sc = ski.channel();
+                if (isExceptFds && (sc instanceof SocketChannelImpl)
+                        && ((SocketChannelImpl) sc).isNetSocket()
+                        && discardUrgentData(desc)) {
                     continue;
                 }
 
-                int updated = processReadyEvents(rOps, sk, action);
+                int updated = processReadyEvents(rOps, ski, action);
                 if (updated > 0 && me.updateCount != updateCount) {
                     me.updateCount = updateCount;
                     numKeysUpdated++;

src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2020, 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
@@ -28,6 +28,7 @@ package sun.nio.fs;
 import java.nio.file.*;
 import java.nio.file.attribute.*;
 import java.nio.channels.*;
+import java.nio.charset.StandardCharsets;
 import java.net.URI;
 import java.util.concurrent.ExecutorService;
 import java.io.*;
@@ -622,4 +623,12 @@ class WindowsFileSystemProvider
         String target = WindowsLinkSupport.readLink(link);
         return WindowsPath.createFromNormalizedPath(fs, target);
     }
+
+    @Override
+    public byte[] getSunPathForSocketFile(Path obj) {
+        WindowsPath file = WindowsPath.toWindowsPath(obj);
+        String s = file.toString();
+        return s.getBytes(StandardCharsets.UTF_8);
+    }
+
 }

src/java.base/windows/conf/net.properties

@@ -0,0 +1,19 @@
+#
+# Default directory where automatically bound Unix domain server
+# sockets are stored. Sockets are automatically bound when bound
+# with a null address.
+#
+# The search order for the directory on Windows is:
+#
+# 1. System property "jdk.net.unixdomain.tmpdir"
+#
+# 2. Networking property "jdk.net.unixdomain.tmpdir" specified
+#    in this file (not set by default)
+#
+# 3. The TEMP environment variable (the effective default)
+#
+# 4. The java.io.tmpdir system property
+#
+#jdk.net.unixdomain.tmpdir=
+#
+

src/java.base/windows/native/libnio/ch/UnixDomainSockets.c

@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2020, 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
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include <windows.h>
+#include <winsock2.h>
+
+#include "jni.h"
+#include "jni_util.h"
+#include "jvm.h"
+#include "jlong.h"
+#include "nio.h"
+#include "nio_util.h"
+#include "net_util.h"
+
+#include "java_net_InetAddress.h"
+#include "sun_nio_ch_Net.h"
+#include "sun_nio_ch_PollArrayWrapper.h"
+
+jbyteArray sockaddrToUnixAddressBytes(JNIEnv *env, struct sockaddr_un *sa, socklen_t len)
+{
+    if (sa->sun_family == AF_UNIX) {
+        int namelen = (int)strlen(sa->sun_path);
+        jbyteArray name = (*env)->NewByteArray(env, namelen);
+        if (name != NULL) {
+            (*env)->SetByteArrayRegion(env, name, 0, namelen, (jbyte*)sa->sun_path);
+            if ((*env)->ExceptionOccurred(env)) {
+                return NULL;
+            }
+        }
+        return name;
+    }
+    return NULL;
+}
+
+jint unixSocketAddressToSockaddr(JNIEnv *env, jbyteArray addr, struct sockaddr_un *sa, int *len)
+{
+    memset(sa, 0, sizeof(struct sockaddr_un));
+    sa->sun_family = AF_UNIX;
+    if (addr == 0L) {
+        /* Do explicit bind on Windows */
+        *len = (int)(offsetof(struct sockaddr_un, sun_path));
+        return 0;
+    }
+    int ret;
+    jboolean isCopy;
+    char *pname = (*env)->GetByteArrayElements(env, addr, &isCopy);
+    if (pname == NULL) {
+        JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "Unix domain path not present");
+        return -1;
+    }
+
+    size_t name_len = (size_t)(*env)->GetArrayLength(env, addr);
+    if (name_len > MAX_UNIX_DOMAIN_PATH_LEN) {
+        JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException", "Unix domain path too long");
+        ret = -1;
+    } else {
+        strncpy(sa->sun_path, pname, name_len);
+        *len = (int)(offsetof(struct sockaddr_un, sun_path) + name_len);
+        ret = 0;
+    }
+    (*env)->ReleaseByteArrayElements(env, addr, pname, JNI_ABORT);
+    return ret;
+}
+
+JNIEXPORT jboolean JNICALL
+Java_sun_nio_ch_UnixDomainSockets_socketSupported(JNIEnv *env, jclass cl)
+{
+    SOCKET s = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (s == INVALID_SOCKET) {
+        return JNI_FALSE;
+    }
+    closesocket(s);
+    return JNI_TRUE;
+}
+
+JNIEXPORT jint JNICALL
+Java_sun_nio_ch_UnixDomainSockets_socket0(JNIEnv *env, jclass cl)
+{
+    SOCKET s = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (s == INVALID_SOCKET) {
+        return handleSocketError(env, WSAGetLastError());
+    }
+    SetHandleInformation((HANDLE)s, HANDLE_FLAG_INHERIT, 0);
+    return (int)s;
+}
+
+/**
+ * Windows does not support auto bind. So, the windows version of unixSocketAddressToSockaddr
+ * looks out for a null 'uaddr' and handles it specially
+ */
+JNIEXPORT void JNICALL
+Java_sun_nio_ch_UnixDomainSockets_bind0(JNIEnv *env, jclass clazz, jobject fdo, jbyteArray addr)
+{
+    struct sockaddr_un sa;
+    int sa_len = 0;
+    int rv = 0;
+
+    if (unixSocketAddressToSockaddr(env, addr, &sa, &sa_len) != 0)
+        return;
+
+    rv = bind(fdval(env, fdo), (struct sockaddr *)&sa, sa_len);
+    if (rv == SOCKET_ERROR) {
+        int err = WSAGetLastError();
+        NET_ThrowNew(env, err, "bind");
+    }
+}
+
+JNIEXPORT jint JNICALL
+Java_sun_nio_ch_UnixDomainSockets_connect0(JNIEnv *env, jclass clazz, jobject fdo, jbyteArray addr)
+{
+    struct sockaddr_un sa;
+    int sa_len = 0;
+    int rv;
+
+    if (unixSocketAddressToSockaddr(env, addr, &sa, &sa_len) != 0) {
+        return IOS_THROWN;
+    }
+
+    rv = connect(fdval(env, fdo), (const struct sockaddr *)&sa, sa_len);
+    if (rv != 0) {
+        int err = WSAGetLastError();
+        if (err == WSAEINPROGRESS || err == WSAEWOULDBLOCK) {
+            return IOS_UNAVAILABLE;
+        }
+        NET_ThrowNew(env, err, "connect");
+        return IOS_THROWN;
+    }
+    return 1;
+}
+
+JNIEXPORT jint JNICALL
+Java_sun_nio_ch_UnixDomainSockets_accept0(JNIEnv *env, jclass clazz, jobject fdo, jobject newfdo,
+                                          jobjectArray array)
+{
+    jint fd = fdval(env, fdo);
+    jint newfd;
+    struct sockaddr_un sa;
+    socklen_t sa_len = sizeof(sa);
+    jbyteArray address;
+
+    memset((char *)&sa, 0, sizeof(sa));
+    newfd = (jint) accept(fd, (struct sockaddr *)&sa, &sa_len);
+    if (newfd == INVALID_SOCKET) {
+        int theErr = (jint)WSAGetLastError();
+        if (theErr == WSAEWOULDBLOCK) {
+            return IOS_UNAVAILABLE;
+        }
+        JNU_ThrowIOExceptionWithLastError(env, "Accept failed");
+        return IOS_THROWN;
+    }
+
+    SetHandleInformation((HANDLE)(UINT_PTR)newfd, HANDLE_FLAG_INHERIT, 0);
+    setfdval(env, newfdo, newfd);
+
+    address = sockaddrToUnixAddressBytes(env, &sa, sa_len);
+    CHECK_NULL_RETURN(address, IOS_THROWN);
+    (*env)->SetObjectArrayElement(env, array, 0, address);
+
+    return 1;
+}
+
+JNIEXPORT jbyteArray JNICALL
+Java_sun_nio_ch_UnixDomainSockets_localAddress0(JNIEnv *env, jclass clazz, jobject fdo)
+{
+    struct sockaddr_un sa;
+    int sa_len = sizeof(sa);
+
+    if (getsockname(fdval(env, fdo), (struct sockaddr *)&sa, &sa_len) == SOCKET_ERROR) {
+        JNU_ThrowIOExceptionWithLastError(env, "getsockname");
+        return NULL;
+    }
+    return sockaddrToUnixAddressBytes(env, &sa, sa_len);
+}
+

src/java.base/windows/native/libnio/ch/nio_util.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, 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
@@ -24,6 +24,8 @@
  */
 
 #include <winsock2.h>
+#include <ws2tcpip.h>
+#include <afunix.h>
 
 #include "jni.h"
 
@@ -35,6 +37,9 @@
  */
 #define MAX_BUFFER_SIZE             ((128*1024)-1)
 
+#define MAX_UNIX_DOMAIN_PATH_LEN \
+        (int)(sizeof(((struct sockaddr_un *)0)->sun_path)-2)
+
 jint fdval(JNIEnv *env, jobject fdo);
 void setfdval(JNIEnv *env, jobject fdo, jint val);
 jlong handleval(JNIEnv *env, jobject fdo);
@@ -74,3 +79,11 @@ struct iovec {
     /* POLLCONN must not equal any of the other constants (see winsock2.h).   */
     #define POLLCONN     0x2000
 #endif
+
+/* Defined in UnixDomainSockets.c */
+
+jbyteArray sockaddrToUnixAddressBytes(JNIEnv *env, struct sockaddr_un *sa, socklen_t len);
+
+jint unixSocketAddressToSockaddr(JNIEnv *env, jbyteArray uaddr,
+                                struct sockaddr_un *sa, int *len);
+