1 /*

     2  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 #include <windows.h>

    27 #include <winsock2.h>

    28 

    29 #include "jvm.h"

    30 #include "jni_util.h"

    31 #include "net_util.h"

    32 

    33 #include "java_net_AbstractPlainDatagramSocketImpl.h"

    34 

    35 static jfieldID IO_fd_fdID = NULL;

    36 static jfieldID apdsi_fdID = NULL;

    37 

    38 static jfieldID apdsi_fd1ID = NULL;

    39 static jclass two_stacks_clazz = NULL;

    40 

    41 

    42 /*

    43  * Class:     java_net_AbstractPlainDatagramSocketImpl

    44  * Method:    init

    45  * Signature: ()V

    46  */

    47 JNIEXPORT void JNICALL

    48 Java_java_net_AbstractPlainDatagramSocketImpl_init(JNIEnv *env, jclass cls) {

    49 

    50     apdsi_fdID = (*env)->GetFieldID(env, cls, "fd",

    51                                    "Ljava/io/FileDescriptor;");

    52     CHECK_NULL(apdsi_fdID);

    53     IO_fd_fdID = NET_GetFileDescriptorID(env);

    54     CHECK_NULL(IO_fd_fdID);

    55 

    56     two_stacks_clazz = (*env)->FindClass(env, "java/net/TwoStacksPlainDatagramSocketImpl");

    57     CHECK_NULL(two_stacks_clazz);

    58 

    59     /* Handle both TwoStacks and DualStack here */

    60 

    61     if (JNU_Equals(env, cls, two_stacks_clazz)) {

    62         /* fd1 present only in TwoStack.. */

    63         apdsi_fd1ID = (*env)->GetFieldID(env, cls, "fd1",

    64                                    "Ljava/io/FileDescriptor;");

    65         CHECK_NULL(apdsi_fd1ID);

    66     }

    67 

    68     JNU_CHECK_EXCEPTION(env);

    69 }

    70 

    71 /*

    72  * Class:     java_net_AbstractPlainDatagramSocketImpl

    73  * Method:    dataAvailable

    74  * Signature: ()I

    75  */

    76 JNIEXPORT jint JNICALL Java_java_net_AbstractPlainDatagramSocketImpl_dataAvailable

    77 (JNIEnv *env, jobject this) {

    78     SOCKET fd;

    79     SOCKET fd1;

    80     int  rv = -1, rv1 = -1;

    81     jobject fdObj = (*env)->GetObjectField(env, this, apdsi_fdID);

    82 

    83     if (!IS_NULL(fdObj)) {

    84         int retval = 0;

    85         fd = (SOCKET)(*env)->GetIntField(env, fdObj, IO_fd_fdID);

    86         rv = ioctlsocket(fd, FIONREAD, &retval);

    87         if (retval > 0) {

    88             return retval;

    89         }

    90     }

    91 

    92     if (!IS_NULL(apdsi_fd1ID)) {

    93         /* TwoStacks */

    94         jobject fd1Obj = (*env)->GetObjectField(env, this, apdsi_fd1ID);

    95         if (!IS_NULL(fd1Obj)) {

    96             int retval = 0;

    97             fd1 = (SOCKET)(*env)->GetIntField(env, fd1Obj, IO_fd_fdID);

    98             rv1 = ioctlsocket(fd1, FIONREAD, &retval);

    99             if (retval > 0) {

   100                 return retval;

   101             }

   102         }

   103     }

   104 

   105     if (rv < 0 && rv1 < 0) {

   106         JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException",

   107                             "Socket closed");

   108         return -1;

   109     }

   110 

   111     return 0;

   112 }

   113