/*

 * Copyright (c) 2000, 2019, 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 <sys/mman.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <sys/types.h>

#include <unistd.h>

#if defined(__linux__) || defined(__solaris__)

#include <sys/sendfile.h>

#elif defined(_AIX)

#include <string.h>

#include <sys/socket.h>

#elif defined(_ALLBSD_SOURCE)

#include <sys/socket.h>

#include <sys/uio.h>

#define lseek64 lseek

#define mmap64 mmap

#endif

#include "jni.h"

#include "jni_util.h"

#include "jlong.h"

#include "nio.h"

#include "nio_util.h"

#include "sun_nio_ch_FileChannelImpl.h"

#include "java_lang_Integer.h"

#include <assert.h>

static jfieldID chan_fd;        /* jobject 'fd' in sun.nio.ch.FileChannelImpl */

JNIEXPORT jlong JNICALL

Java_sun_nio_ch_FileChannelImpl_initIDs(JNIEnv *env, jclass clazz)

{

    jlong pageSize = sysconf(_SC_PAGESIZE);

    chan_fd = (*env)->GetFieldID(env, clazz, "fd", "Ljava/io/FileDescriptor;");

    return pageSize;

}

static jlong

handle(JNIEnv *env, jlong rv, char *msg)

{

    if (rv >= 0)

        return rv;

    if (errno == EINTR)

        return IOS_INTERRUPTED;

    JNU_ThrowIOExceptionWithLastError(env, msg);

    return IOS_THROWN;

}

JNIEXPORT jlong JNICALL

Java_sun_nio_ch_FileChannelImpl_map0(JNIEnv *env, jobject this,

                                     jint prot, jlong off, jlong len, jboolean map_sync)

{

    void *mapAddress = 0;

    jobject fdo = (*env)->GetObjectField(env, this, chan_fd);

    jint fd = fdval(env, fdo);

    int protections = 0;

    int flags = 0;

    // should never be called with map_sync and prot == PRIVATE

    assert((prot != sun_nio_ch_FileChannelImpl_MAP_PV) || !map_sync);

    if (prot == sun_nio_ch_FileChannelImpl_MAP_RO) {

        protections = PROT_READ;

        flags = MAP_SHARED;

    } else if (prot == sun_nio_ch_FileChannelImpl_MAP_RW) {

        protections = PROT_WRITE | PROT_READ;

        flags = MAP_SHARED;

    } else if (prot == sun_nio_ch_FileChannelImpl_MAP_PV) {

        protections =  PROT_WRITE | PROT_READ;

        flags = MAP_PRIVATE;

    }

    // if MAP_SYNC and MAP_SHARED_VALIDATE are not defined then it is

    // best to define them here. This ensures the code compiles on old

    // OS releases which do not provide the relevant headers. If run

    // on the same machine then it will work if the kernel contains

    // the necessary support otherwise mmap should fail with an

    // invalid argument error

#ifndef MAP_SYNC

#define MAP_SYNC 0x80000

#endif

#ifndef MAP_SHARED_VALIDATE

#define MAP_SHARED_VALIDATE 0x03

#endif

    if (map_sync) {

        // ensure

        //  1) this is Linux on AArch64 or x86_64

        //  2) the mmap APIs are available/ at compile time

#if !defined(LINUX) || ! (defined(aarch64) || (defined(amd64) && defined(_LP64)))

        // TODO - implement for solaris/AIX/BSD/WINDOWS and for 32 bit

        JNU_ThrowInternalError(env, "should never call map on platform where MAP_SYNC is unimplemented");

        return IOS_THROWN;

#else

        flags |= MAP_SYNC | MAP_SHARED_VALIDATE;

#endif

    }

    mapAddress = mmap64(

        0,                    /* Let OS decide location */

        len,                  /* Number of bytes to map */

        protections,          /* File permissions */

        flags,                /* Changes are shared */

        fd,                   /* File descriptor of mapped file */

        off);                 /* Offset into file */

    if (mapAddress == MAP_FAILED) {

        if (map_sync && errno == ENOTSUP) {

            JNU_ThrowIOExceptionWithLastError(env, "map with mode MAP_SYNC unsupported");

            return IOS_THROWN;

        }

        if (errno == ENOMEM) {

            JNU_ThrowOutOfMemoryError(env, "Map failed");

            return IOS_THROWN;

        }

        return handle(env, -1, "Map failed");

    }

    return ((jlong) (unsigned long) mapAddress);

}

JNIEXPORT jint JNICALL

Java_sun_nio_ch_FileChannelImpl_unmap0(JNIEnv *env, jobject this,

                                       jlong address, jlong len)

{

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

    return handle(env,

                  munmap(a, (size_t)len),

                  "Unmap failed");

}

JNIEXPORT jlong JNICALL

Java_sun_nio_ch_FileChannelImpl_transferTo0(JNIEnv *env, jobject this,

                                            jobject srcFDO,

                                            jlong position, jlong count,

                                            jobject dstFDO)

{

    jint srcFD = fdval(env, srcFDO);

    jint dstFD = fdval(env, dstFDO);

#if defined(__linux__)

    off64_t offset = (off64_t)position;

    jlong n = sendfile64(dstFD, srcFD, &offset, (size_t)count);

    if (n < 0) {

        if (errno == EAGAIN)

            return IOS_UNAVAILABLE;

        if ((errno == EINVAL) && ((ssize_t)count >= 0))

            return IOS_UNSUPPORTED_CASE;

        if (errno == EINTR) {

            return IOS_INTERRUPTED;

        }

        JNU_ThrowIOExceptionWithLastError(env, "Transfer failed");

        return IOS_THROWN;

    }

    return n;

#elif defined (__solaris__)

    sendfilevec64_t sfv;

    size_t numBytes = 0;

    jlong result;

    sfv.sfv_fd = srcFD;

    sfv.sfv_flag = 0;

    sfv.sfv_off = (off64_t)position;

    sfv.sfv_len = count;

    result = sendfilev64(dstFD, &sfv, 1, &numBytes);

    /* Solaris sendfilev() will return -1 even if some bytes have been

     * transferred, so we check numBytes first.

     */

    if (numBytes > 0)

        return numBytes;

    if (result < 0) {

        if (errno == EAGAIN)

            return IOS_UNAVAILABLE;

        if (errno == EOPNOTSUPP)

            return IOS_UNSUPPORTED_CASE;

        if ((errno == EINVAL) && ((ssize_t)count >= 0))

            return IOS_UNSUPPORTED_CASE;

        if (errno == EINTR)

            return IOS_INTERRUPTED;

        JNU_ThrowIOExceptionWithLastError(env, "Transfer failed");

        return IOS_THROWN;

    }

    return result;

#elif defined(__APPLE__)

    off_t numBytes;

    int result;

    numBytes = count;

    result = sendfile(srcFD, dstFD, position, &numBytes, NULL, 0);

    if (numBytes > 0)

        return numBytes;

    if (result == -1) {

        if (errno == EAGAIN)

            return IOS_UNAVAILABLE;

        if (errno == EOPNOTSUPP || errno == ENOTSOCK || errno == ENOTCONN)

            return IOS_UNSUPPORTED_CASE;

        if ((errno == EINVAL) && ((ssize_t)count >= 0))

            return IOS_UNSUPPORTED_CASE;

        if (errno == EINTR)

            return IOS_INTERRUPTED;

        JNU_ThrowIOExceptionWithLastError(env, "Transfer failed");

        return IOS_THROWN;

    }

    return result;

#elif defined(_AIX)

    jlong max = (jlong)java_lang_Integer_MAX_VALUE;

    struct sf_parms sf_iobuf;

    jlong result;

    if (position > max)

        return IOS_UNSUPPORTED_CASE;

    if (count > max)

        count = max;

    memset(&sf_iobuf, 0, sizeof(sf_iobuf));

    sf_iobuf.file_descriptor = srcFD;

    sf_iobuf.file_offset = (off_t)position;

    sf_iobuf.file_bytes = count;

    result = send_file(&dstFD, &sf_iobuf, SF_SYNC_CACHE);

    /* AIX send_file() will return 0 when this operation complete successfully,

     * return 1 when partial bytes transfered and return -1 when an error has

     * Occured.

     */

    if (result == -1) {

        if (errno == EWOULDBLOCK)

            return IOS_UNAVAILABLE;

        if ((errno == EINVAL) && ((ssize_t)count >= 0))

            return IOS_UNSUPPORTED_CASE;

        if (errno == EINTR)

            return IOS_INTERRUPTED;

        if (errno == ENOTSOCK)

            return IOS_UNSUPPORTED;

        JNU_ThrowIOExceptionWithLastError(env, "Transfer failed");

        return IOS_THROWN;

    }

    if (sf_iobuf.bytes_sent > 0)

        return (jlong)sf_iobuf.bytes_sent;

    return IOS_UNSUPPORTED_CASE;

#else

    return IOS_UNSUPPORTED_CASE;

#endif

}