/* XMRig
 * Copyright (c) 2018-2020 tevador     <tevador@gmail.com>
 * Copyright (c) 2018-2021 SChernykh   <https://github.com/SChernykh>
 * Copyright (c) 2016-2021 XMRig       <https://github.com/xmrig>, <support@xmrig.com>
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program. If not, see <http://www.gnu.org/licenses/>.
 */


#include <winsock2.h>
#include <windows.h>
#include <ntsecapi.h>
#include <tchar.h>


#include "crypto/common/VirtualMemory.h"
#include "base/io/log/Log.h"
#include "crypto/common/portable/mm_malloc.h"


#ifdef XMRIG_SECURE_JIT
#   define SECURE_PAGE_EXECUTE_READWRITE PAGE_READWRITE
#else
#   define SECURE_PAGE_EXECUTE_READWRITE PAGE_EXECUTE_READWRITE
#endif


namespace xmrig {


static bool hugepagesAvailable = false;


/*****************************************************************
SetLockPagesPrivilege: a function to obtain or
release the privilege of locking physical pages.

Inputs:

HANDLE hProcess: Handle for the process for which the
privilege is needed

BOOL bEnable: Enable (TRUE) or disable?

Return value: TRUE indicates success, FALSE failure.

*****************************************************************/
/**
 * AWE Example: https://msdn.microsoft.com/en-us/library/windows/desktop/aa366531(v=vs.85).aspx
 * Creating a File Mapping Using Large Pages: https://msdn.microsoft.com/en-us/library/aa366543(VS.85).aspx
 */
static BOOL SetLockPagesPrivilege() {
    HANDLE token;

    if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, &token)) {
        return FALSE;
    }

    TOKEN_PRIVILEGES tp;
    tp.PrivilegeCount = 1;
    tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

    if (!LookupPrivilegeValue(nullptr, SE_LOCK_MEMORY_NAME, &(tp.Privileges[0].Luid))) {
        return FALSE;
    }

    BOOL rc = AdjustTokenPrivileges(token, FALSE, (PTOKEN_PRIVILEGES) &tp, 0, nullptr, nullptr);
    if (!rc || GetLastError() != ERROR_SUCCESS) {
        return FALSE;
    }

    CloseHandle(token);

    return TRUE;
}


static LSA_UNICODE_STRING StringToLsaUnicodeString(LPCTSTR string) {
    LSA_UNICODE_STRING lsaString;

    const auto dwLen = (DWORD) wcslen(string);
    lsaString.Buffer = (LPWSTR) string;
    lsaString.Length = (USHORT)((dwLen) * sizeof(WCHAR));
    lsaString.MaximumLength = (USHORT)((dwLen + 1) * sizeof(WCHAR));
    return lsaString;
}


static BOOL ObtainLockPagesPrivilege() {
    HANDLE token;
    PTOKEN_USER user = nullptr;

    if (OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &token)) {
        DWORD size = 0;

        GetTokenInformation(token, TokenUser, nullptr, 0, &size);
        if (size) {
            user = (PTOKEN_USER) LocalAlloc(LPTR, size);
        }

        GetTokenInformation(token, TokenUser, user, size, &size);
        CloseHandle(token);
    }

    if (!user) {
        return FALSE;
    }

    LSA_HANDLE handle;
    LSA_OBJECT_ATTRIBUTES attributes;
    ZeroMemory(&attributes, sizeof(attributes));

    BOOL result = FALSE;
    if (LsaOpenPolicy(nullptr, &attributes, POLICY_ALL_ACCESS, &handle) == 0) {
        LSA_UNICODE_STRING str = StringToLsaUnicodeString(_T(SE_LOCK_MEMORY_NAME));

        if (LsaAddAccountRights(handle, user->User.Sid, &str, 1) == 0) {
            LOG_NOTICE("Huge pages support was successfully enabled, but reboot required to use it");
            result = TRUE;
        }

        LsaClose(handle);
    }

    LocalFree(user);
    return result;
}


static BOOL TrySetLockPagesPrivilege() {
    if (SetLockPagesPrivilege()) {
        return TRUE;
    }

    return ObtainLockPagesPrivilege() && SetLockPagesPrivilege();
}


} // namespace xmrig


bool xmrig::VirtualMemory::isHugepagesAvailable()
{
    return hugepagesAvailable;
}


bool xmrig::VirtualMemory::isOneGbPagesAvailable()
{
    return false;
}


bool xmrig::VirtualMemory::protectRW(void *p, size_t size)
{
    DWORD oldProtect;

    return VirtualProtect(p, size, PAGE_READWRITE, &oldProtect) != 0;
}


bool xmrig::VirtualMemory::protectRWX(void *p, size_t size)
{
    DWORD oldProtect;

    return VirtualProtect(p, size, PAGE_EXECUTE_READWRITE, &oldProtect) != 0;
}


bool xmrig::VirtualMemory::protectRX(void *p, size_t size)
{
    DWORD oldProtect;

    return VirtualProtect(p, size, PAGE_EXECUTE_READ, &oldProtect) != 0;
}


void *xmrig::VirtualMemory::allocateExecutableMemory(size_t size, bool hugePages)
{
    void* result = nullptr;

    if (hugePages) {
        result = VirtualAlloc(nullptr, align(size), MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, SECURE_PAGE_EXECUTE_READWRITE);
    }

    if (!result) {
        result = VirtualAlloc(nullptr, size, MEM_COMMIT | MEM_RESERVE, SECURE_PAGE_EXECUTE_READWRITE);
    }

    return result;
}


void *xmrig::VirtualMemory::allocateLargePagesMemory(size_t size)
{
    const size_t min = GetLargePageMinimum();
    void *mem        = nullptr;

    if (min > 0) {
        mem = VirtualAlloc(nullptr, align(size, min), MEM_COMMIT | MEM_RESERVE | MEM_LARGE_PAGES, PAGE_READWRITE);
    }

    return mem;
}


void *xmrig::VirtualMemory::allocateOneGbPagesMemory(size_t)
{
    return nullptr;
}


void xmrig::VirtualMemory::flushInstructionCache(void *p, size_t size)
{
    ::FlushInstructionCache(GetCurrentProcess(), p, size);
}


void xmrig::VirtualMemory::freeLargePagesMemory(void *p, size_t)
{
    VirtualFree(p, 0, MEM_RELEASE);
}


void xmrig::VirtualMemory::osInit(size_t hugePageSize)
{
    if (hugePageSize) {
        hugepagesAvailable = TrySetLockPagesPrivilege();
    }
}


bool xmrig::VirtualMemory::allocateLargePagesMemory()
{
    m_scratchpad = static_cast<uint8_t*>(allocateLargePagesMemory(m_size));
    if (m_scratchpad) {
        m_flags.set(FLAG_HUGEPAGES, true);

        return true;
    }

    return false;
}

bool xmrig::VirtualMemory::allocateOneGbPagesMemory()
{
    m_scratchpad = nullptr;
    return false;
}


void xmrig::VirtualMemory::freeLargePagesMemory()
{
    freeLargePagesMemory(m_scratchpad, m_size);
}