/*

 * Copyright 2001-2007 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

#include "jni.h"

#include "jni_util.h"

#include "jvm.h"

#include "jlong.h"

#include <io.h>

#include "sun_nio_ch_DatagramChannelImpl.h"

#include "nio.h"

#include "nio_util.h"

#include "net_util.h"

#include <winsock2.h>

static jfieldID isa_addrID;     /* address in java.net.InetSocketAddress */

static jfieldID isa_portID;     /* port in java.net.InetSocketAddress */

static jfieldID dci_senderID;   /* sender in sun.nio.ch.DatagramChannelImpl */

static jfieldID dci_senderAddrID; /* sender InetAddress in sun.nio.ch.DatagramChannelImpl */

static jfieldID dci_senderPortID; /* sender port in sun.nio.ch.DatagramChannelImpl */

static jfieldID ia_addrID;

static jfieldID ia_famID;

static jclass isa_class;        /* java.net.InetSocketAddress */

static jclass ia_class;

static jmethodID isa_ctorID;    /*   .InetSocketAddress(InetAddress, int) */

static jmethodID ia_ctorID;

/*

 * Returns JNI_TRUE if DatagramChannelImpl has already cached an

 * InetAddress/port corresponding to the socket address.

 */

static jboolean isSenderCached(JNIEnv *env, jobject this, struct sockaddr_in *sa) {

    jobject senderAddr;

    /* shouldn't happen until we have dual IPv4/IPv6 stack (post-XP ?) */

    if (sa->sin_family != AF_INET) {

        return JNI_FALSE;

    }

    /*

     * Compare source address to cached InetAddress

     */

    senderAddr = (*env)->GetObjectField(env, this, dci_senderAddrID);

    if (senderAddr == NULL) {

        return JNI_FALSE;

    }

    if ((jint)ntohl(sa->sin_addr.s_addr) !=

        (*env)->GetIntField(env, senderAddr, ia_addrID)) {

        return JNI_FALSE;

    }

    /*

     * Compare source port to cached port

     */

    if ((jint)ntohs(sa->sin_port) !=

        (*env)->GetIntField(env, this, dci_senderPortID)) {

        return JNI_FALSE;

    }

    return JNI_TRUE;

}

JNIEXPORT void JNICALL

Java_sun_nio_ch_DatagramChannelImpl_initIDs(JNIEnv *env, jclass clazz)

{

    clazz = (*env)->FindClass(env, "java/net/InetSocketAddress");

    isa_class = (*env)->NewGlobalRef(env, clazz);

    isa_ctorID = (*env)->GetMethodID(env, clazz, "<init>",

                                     "(Ljava/net/InetAddress;I)V");

    isa_addrID = (*env)->GetFieldID(env, clazz, "addr",

                                    "Ljava/net/InetAddress;");

    isa_portID = (*env)->GetFieldID(env, clazz, "port", "I");

    clazz = (*env)->FindClass(env, "sun/nio/ch/DatagramChannelImpl");

    dci_senderID = (*env)->GetFieldID(env, clazz, "sender",

                                      "Ljava/net/SocketAddress;");

    dci_senderAddrID = (*env)->GetFieldID(env, clazz,

                                          "cachedSenderInetAddress",

                                          "Ljava/net/InetAddress;");

    dci_senderPortID = (*env)->GetFieldID(env, clazz,

                                          "cachedSenderPort", "I");

    clazz = (*env)->FindClass(env, "java/net/Inet4Address");

    ia_class = (*env)->NewGlobalRef(env, clazz);

    ia_addrID = (*env)->GetFieldID(env, clazz, "address", "I");

    ia_famID = (*env)->GetFieldID(env, clazz, "family", "I");

    ia_ctorID = (*env)->GetMethodID(env, clazz, "<init>", "()V");

}

/*

 * Return JNI_TRUE if this Windows edition supports ICMP Port Unreachable

 */

__inline static jboolean supportPortUnreachable() {

    static jboolean initDone;

    static jboolean portUnreachableSupported;

    if (!initDone) {

        OSVERSIONINFO ver;

        ver.dwOSVersionInfoSize = sizeof(ver);

        GetVersionEx(&ver);

        if (ver.dwPlatformId == VER_PLATFORM_WIN32_NT && ver.dwMajorVersion >= 5) {

            portUnreachableSupported = JNI_TRUE;

        } else {

            portUnreachableSupported = JNI_FALSE;

        }

        initDone = JNI_TRUE;

    }

    return portUnreachableSupported;

}

/*

 * This function "purges" all outstanding ICMP port unreachable packets

 * outstanding on a socket and returns JNI_TRUE if any ICMP messages

 * have been purged. The rational for purging is to emulate normal BSD

 * behaviour whereby receiving a "connection reset" status resets the

 * socket.

 */

jboolean purgeOutstandingICMP(JNIEnv *env, jclass clazz, jint fd)

{

    jboolean got_icmp = JNI_FALSE;

    char buf[1];

    fd_set tbl;

    struct timeval t = { 0, 0 };

    struct sockaddr_in rmtaddr;

    int addrlen = sizeof(rmtaddr);

    /*

     * A no-op if this OS doesn't support it.

     */

    if (!supportPortUnreachable()) {

        return JNI_FALSE;

    }

    /*

     * Peek at the queue to see if there is an ICMP port unreachable. If there

     * is then receive it.

     */

    FD_ZERO(&tbl);

    FD_SET((u_int)fd, &tbl);

    while(1) {

        if (select(/*ignored*/fd+1, &tbl, 0, 0, &t) <= 0) {

            break;

        }

        if (recvfrom(fd, buf, 1, MSG_PEEK,

                     (struct sockaddr *)&rmtaddr, &addrlen) != SOCKET_ERROR) {

            break;

        }

        if (WSAGetLastError() != WSAECONNRESET) {

            /* some other error - we don't care here */

            break;

        }

        recvfrom(fd, buf, 1, 0,  (struct sockaddr *)&rmtaddr, &addrlen);

        got_icmp = JNI_TRUE;

    }

    return got_icmp;

}

JNIEXPORT void JNICALL

Java_sun_nio_ch_DatagramChannelImpl_disconnect0(JNIEnv *env, jobject this,

                                                jobject fdo)

{

    jint fd = fdval(env, fdo);

    int rv = 0;

    struct sockaddr_in psa;

    int sa_len = sizeof(psa);

    memset(&psa, 0, sa_len);

    rv = connect((SOCKET)fd, (struct sockaddr *)&psa, sa_len);

    if (rv == SOCKET_ERROR) {

        handleSocketError(env, WSAGetLastError());

    }

}

JNIEXPORT jint JNICALL

Java_sun_nio_ch_DatagramChannelImpl_receive0(JNIEnv *env, jobject this,

                                            jobject fdo, jlong address,

                                            jint len, jboolean connected)

{

    jint fd = fdval(env, fdo);

    void *buf = (void *)jlong_to_ptr(address);

    struct sockaddr_in psa;

    int sa_len = sizeof(psa);

    BOOL retry = FALSE;

    jint n;

    do {

        retry = FALSE;

        n = recvfrom((SOCKET)fd,

                     (char *)buf,

                     len,

                     0,

                     (struct sockaddr *)&psa,

                     &sa_len);

        if (n == SOCKET_ERROR) {

            int theErr = (jint)WSAGetLastError();

            if (theErr == WSAEMSGSIZE) {

                /* Spec says the rest of the data will be discarded... */

                n = len;

            } else if (theErr == WSAECONNRESET) {

                purgeOutstandingICMP(env, this, fd);

                if (connected == JNI_FALSE) {

                    retry = TRUE;

                } else {

                    JNU_ThrowByName(env, JNU_JAVANETPKG "PortUnreachableException", 0);

                    return IOS_THROWN;

                }

            } else if (theErr == WSAEWOULDBLOCK) {

                return IOS_UNAVAILABLE;

            } else return handleSocketError(env, theErr);

        }

    } while (retry);

    if (!isSenderCached(env, this, &psa)) {

        int port = ntohs(psa.sin_port);

        jobject ia = (*env)->NewObject(env, ia_class, ia_ctorID);

        jobject isa = NULL;

        if (psa.sin_family != AF_INET) {

            JNU_ThrowByName(env, JNU_JAVANETPKG "SocketException",

                            "Protocol family unavailable");

        }

        if (ia != NULL) {

            // populate InetAddress (assumes AF_INET)

            (*env)->SetIntField(env, ia, ia_addrID, ntohl(psa.sin_addr.s_addr));

            // create InetSocketAddress

            isa = (*env)->NewObject(env, isa_class, isa_ctorID, ia, port);

        }

        if (isa == NULL) {

            JNU_ThrowOutOfMemoryError(env, "heap allocation failed");

            return IOS_THROWN;

        }

        // update cachedSenderInetAddress/cachedSenderPort

        (*env)->SetObjectField(env, this, dci_senderAddrID, ia);

        (*env)->SetIntField(env, this, dci_senderPortID, port);

        // update sender

        (*env)->SetObjectField(env, this, dci_senderID, isa);

    }

    return n;

}

JNIEXPORT jint JNICALL

Java_sun_nio_ch_DatagramChannelImpl_send0(JNIEnv *env, jobject this,

                                            jobject fdo, jlong address,

                                            jint len, jobject dest)

{

    jint fd = fdval(env, fdo);

    void *buf = (void *)jlong_to_ptr(address);

    SOCKETADDRESS psa;

    int sa_len = sizeof(psa);

    jint rv = 0;

    jobject destAddress = (*env)->GetObjectField(env, dest, isa_addrID);

    jint destPort = (*env)->GetIntField(env, dest, isa_portID);

    if (NET_InetAddressToSockaddr(env, destAddress, destPort,

                                  (struct sockaddr *)&psa,

                                   &sa_len, JNI_FALSE) != 0) {

      return IOS_THROWN;

    }

    rv = sendto((SOCKET)fd,

               buf,

               len,

               0,

               (struct sockaddr *)&psa,

               sa_len);

    if (rv == SOCKET_ERROR) {

        int theErr = (jint)WSAGetLastError();

        if (theErr == WSAEWOULDBLOCK) {

            return IOS_UNAVAILABLE;

        }

        return handleSocketError(env, (jint)WSAGetLastError());

    }

    return rv;

}