/*

 * 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

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

 *

 * 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.

 *

 */

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

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

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");

}

/*

 * 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 };

    SOCKETADDRESS sa;

    int addrlen = sizeof(sa);

    /*

     * 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 *)&sa, &addrlen) != SOCKET_ERROR) {

            break;

        }

        if (WSAGetLastError() != WSAECONNRESET) {

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

            break;

        }

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

    SOCKETADDRESS sa;

    int sa_len = sizeof(sa);

    memset(&sa, 0, sa_len);

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

    SOCKETADDRESS sa;

    int sa_len = sizeof(sa);

    BOOL retry = FALSE;

    jint n;

    jobject senderAddr;

    do {

        retry = FALSE;

        n = recvfrom((SOCKET)fd,

                     (char *)buf,

                     len,

                     0,

                     (struct sockaddr *)&sa,

                     &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 the source address and port match the cached address

     * and port in DatagramChannelImpl then we don't need to

     * create InetAddress and InetSocketAddress objects.

     */

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

    if (senderAddr != NULL) {

        if (!NET_SockaddrEqualsInetAddress(env, (struct sockaddr *)&sa,

                                           senderAddr)) {

            senderAddr = NULL;

        } else {

            jint port = (*env)->GetIntField(env, this, dci_senderPortID);

            if (port != NET_GetPortFromSockaddr((struct sockaddr *)&sa)) {

                senderAddr = NULL;

            }

        }

    }

    if (senderAddr == NULL) {

        jobject isa = NULL;

        int port;

        jobject ia = NET_SockaddrToInetAddress(env, (struct sockaddr *)&sa,

                                               &port);

        if (ia != NULL) {

            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,

                            NET_GetPortFromSockaddr((struct sockaddr *)&sa));

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

    }

    return n;

}

JNIEXPORT jint JNICALL

Java_sun_nio_ch_DatagramChannelImpl_send0(JNIEnv *env, jobject this,

                                          jboolean preferIPv6, jobject fdo,

                                          jlong address, jint len, jobject dest)

{

    jint fd = fdval(env, fdo);

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

    SOCKETADDRESS sa;

    int sa_len;

    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 *)&sa,

                                   &sa_len, preferIPv6) != 0) {

      return IOS_THROWN;

    }

    rv = sendto((SOCKET)fd,

               buf,

               len,

               0,

               (struct sockaddr *)&sa,

               sa_len);

    if (rv == SOCKET_ERROR) {

        int theErr = (jint)WSAGetLastError();

        if (theErr == WSAEWOULDBLOCK) {

            return IOS_UNAVAILABLE;

        }

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

    }

    return rv;

}