/*
 * Copyright (c) 2020, 2024, 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"

/* The winsock provider ID of the Microsoft AF_UNIX implementation */
static GUID MS_PROVIDER_ID  = {0xA00943D9,0x9C2E,0x4633,{0x9B,0x59,0,0x57,0xA3,0x16,0x09,0x94}};

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)->ExceptionCheck(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;
}

static int cmpGuid(GUID *g1, GUID *g2) {
    if (g1->Data1 != g2->Data1)
        return JNI_FALSE;
    if (g1->Data2 != g2->Data2)
        return JNI_FALSE;
    if (g1->Data3 != g2->Data3)
        return JNI_FALSE;
    for (int i=0; i<8; i++) {
        if (g1->Data4[i] != g2->Data4[i])
            return JNI_FALSE;
    }
    return JNI_TRUE;
}

static WSAPROTOCOL_INFOW provider;

JNIEXPORT jboolean JNICALL
Java_sun_nio_ch_UnixDomainSockets_init(JNIEnv *env, jclass cl)
{
    WSAPROTOCOL_INFOW info[5]; // if not large enough, a buffer is malloc'd
    LPWSAPROTOCOL_INFOW infoPtr = &info[0];
    DWORD len = sizeof(info);
    jboolean found = JNI_FALSE;

    /*
     * First locate the Microsoft AF_UNIX Winsock provider
     */
    int result = WSAEnumProtocolsW(0, infoPtr, &len);
    if (result == SOCKET_ERROR) {
        if (GetLastError() == WSAENOBUFS) {
            infoPtr = (LPWSAPROTOCOL_INFOW)malloc(len);
            if (infoPtr == NULL) {
                return JNI_FALSE;
            }
            result = WSAEnumProtocolsW(0, infoPtr, &len);
            if (result == SOCKET_ERROR) {
                free(infoPtr);
                return JNI_FALSE;
            }
        } else {
            return JNI_FALSE;
        }
    }
    for (int i=0; i<result;  i++) {
        if (infoPtr[i].iAddressFamily == AF_UNIX) {
            GUID g = infoPtr[i].ProviderId;
            if (cmpGuid(&g, &MS_PROVIDER_ID)) {
                found = JNI_TRUE;
                provider = infoPtr[i];
                break;
            }
        }
    }
    if (infoPtr != &info[0]) {
        free(infoPtr);
    }
    /*
     * check we can create a socket
     */
    if (found) {
        SOCKET s = WSASocketW(PF_UNIX, SOCK_STREAM, 0, &provider, 0, WSA_FLAG_OVERLAPPED);
        if (s == INVALID_SOCKET) {
            return JNI_FALSE;
        }
        closesocket(s);
    }
    return found;
}

JNIEXPORT jint JNICALL
Java_sun_nio_ch_UnixDomainSockets_socket0(JNIEnv *env, jclass cl)
{
    SOCKET s = WSASocketW(PF_UNIX, SOCK_STREAM, 0, &provider, 0, WSA_FLAG_OVERLAPPED);
    if (s == INVALID_SOCKET) {
        NET_ThrowNew(env, WSAGetLastError(), "WSASocketW");
        return IOS_THROWN;
    }
    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);
}