/* $Id: init.cpp $ */
/** @file
 * IPRT - Init Ring-3.
 */

/*
 * Copyright (C) 2006-2020 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 *
 * The contents of this file may alternatively be used under the terms
 * of the Common Development and Distribution License Version 1.0
 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
 * VirtualBox OSE distribution, in which case the provisions of the
 * CDDL are applicable instead of those of the GPL.
 *
 * You may elect to license modified versions of this file under the
 * terms and conditions of either the GPL or the CDDL or both.
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#define LOG_GROUP RTLOGGROUP_DEFAULT
#include <iprt/types.h>                 /* darwin: UINT32_C and others. */

#ifdef RT_OS_WINDOWS
# include <process.h>
# include <iprt/win/windows.h>
#else
# include <unistd.h>
# ifndef RT_OS_OS2
#  include <pthread.h>
#  include <signal.h>
#  include <errno.h>
#  define IPRT_USE_SIG_CHILD_DUMMY
# endif
#endif
#ifdef RT_OS_OS2
# include <InnoTekLIBC/fork.h>
# define INCL_DOSMISC
# include <os2.h>
#endif
#include <locale.h>

#include <iprt/initterm.h>
#include <iprt/asm.h>
#include <iprt/assert.h>
#include <iprt/errcore.h>
#include <iprt/log.h>
#include <iprt/mem.h>
#include <iprt/path.h>
#include <iprt/time.h>
#include <iprt/string.h>
#include <iprt/param.h>
#ifdef RT_OS_WINDOWS
# include <iprt/utf16.h>
#endif
#if !defined(IN_GUEST) && !defined(RT_NO_GIP)
# include <iprt/file.h>
# include <VBox/sup.h>
#endif
#include <stdlib.h>

#include "init.h"
#include "internal/alignmentchecks.h"
#include "internal/path.h"
#include "internal/process.h"
#include "internal/thread.h"
#include "internal/time.h"


/*********************************************************************************************************************************
*   Global Variables                                                                                                             *
*********************************************************************************************************************************/
/** The number of calls to RTR3Init*. */
static int32_t volatile     g_cUsers = 0;
/** Whether we're currently initializing the IPRT. */
static bool volatile        g_fInitializing = false;

/** The process path.
 * This is used by RTPathExecDir and RTProcGetExecutablePath and set by rtProcInitName. */
DECLHIDDEN(char)            g_szrtProcExePath[RTPATH_MAX];
/** The length of g_szrtProcExePath. */
DECLHIDDEN(size_t)          g_cchrtProcExePath;
/** The length of directory path component of g_szrtProcExePath. */
DECLHIDDEN(size_t)          g_cchrtProcDir;
/** The offset of the process name into g_szrtProcExePath. */
DECLHIDDEN(size_t)          g_offrtProcName;

/** The IPRT init flags. */
static uint32_t             g_fInitFlags;

/** The argument count of the program.  */
static int                  g_crtArgs = -1;
/** The arguments of the program (UTF-8).  This is "leaked". */
static char **              g_papszrtArgs;
/** The original argument vector of the program. */
static char **              g_papszrtOrgArgs;

/**
 * Program start nanosecond TS.
 */
DECLHIDDEN(uint64_t)        g_u64ProgramStartNanoTS;

/**
 * The process identifier of the running process.
 */
DECLHIDDEN(RTPROCESS)       g_ProcessSelf = NIL_RTPROCESS;

/**
 * The current process priority.
 */
DECLHIDDEN(RTPROCPRIORITY)  g_enmProcessPriority = RTPROCPRIORITY_DEFAULT;

/**
 * Set if the atexit callback has been called, i.e. indicating
 * that the process is terminating.
 */
DECLHIDDEN(bool volatile)   g_frtAtExitCalled = false;

#ifdef IPRT_WITH_ALIGNMENT_CHECKS
/**
 * Whether alignment checks are enabled.
 * This is set if the environment variable IPRT_ALIGNMENT_CHECKS is 1.
 */
RTDATADECL(bool) g_fRTAlignmentChecks = false;
#endif


#if defined(RT_OS_DARWIN) || defined(RT_OS_FREEBSD) || defined(RT_OS_NETBSD) || defined(RT_OS_HAIKU) \
 || defined(RT_OS_LINUX)  || defined(RT_OS_OS2)     || defined(RT_OS_SOLARIS) /** @todo add host init hooks everywhere. */
/* Stubs */
DECLHIDDEN(int)  rtR3InitNativeFirst(uint32_t fFlags)     { RT_NOREF_PV(fFlags); return VINF_SUCCESS; }
DECLHIDDEN(int)  rtR3InitNativeFinal(uint32_t fFlags)     { RT_NOREF_PV(fFlags); return VINF_SUCCESS; }
DECLHIDDEN(void) rtR3InitNativeObtrusive(uint32_t fFlags) { RT_NOREF_PV(fFlags); }
#endif


/**
 * atexit callback.
 *
 * This makes sure any loggers are flushed and will later also work the
 * termination callback chain.
 */
static void rtR3ExitCallback(void)
{
    ASMAtomicWriteBool(&g_frtAtExitCalled, true);

    if (g_cUsers > 0)
    {
        PRTLOGGER pLogger = RTLogGetDefaultInstance();
        if (pLogger)
            RTLogFlush(pLogger);

        pLogger = RTLogRelGetDefaultInstance();
        if (pLogger)
            RTLogFlush(pLogger);
    }
}


#ifndef RT_OS_WINDOWS
/**
 * Fork callback, child context.
 */
static void rtR3ForkChildCallback(void)
{
    g_ProcessSelf = getpid();
}
#endif /* RT_OS_WINDOWS */

#ifdef RT_OS_OS2
/** Fork completion callback for OS/2.  Only called in the child. */
static void rtR3ForkOs2ChildCompletionCallback(void *pvArg, int rc, __LIBC_FORKCTX enmCtx)
{
    Assert(enmCtx == __LIBC_FORK_CTX_CHILD); NOREF(enmCtx);
    NOREF(pvArg);

    if (!rc)
        rtR3ForkChildCallback();
}

/** Low-level fork callback for OS/2.  */
int rtR3ForkOs2Child(__LIBC_PFORKHANDLE pForkHandle, __LIBC_FORKOP enmOperation)
{
    if (enmOperation == __LIBC_FORK_OP_EXEC_CHILD)
        return pForkHandle->pfnCompletionCallback(pForkHandle, rtR3ForkOs2ChildCompletionCallback, NULL, __LIBC_FORK_CTX_CHILD);
    return 0;
}

# define static static volatile /** @todo _FORK_CHILD1 causes unresolved externals in optimized builds. Fix macro. */
_FORK_CHILD1(0, rtR3ForkOs2Child);
# undef static
#endif /* RT_OS_OS2 */



/**
 * Internal worker which initializes or re-initializes the
 * program path, name and directory globals.
 *
 * @returns IPRT status code.
 * @param   pszProgramPath  The program path, NULL if not specified.
 */
static int rtR3InitProgramPath(const char *pszProgramPath)
{
    /*
     * We're reserving 32 bytes here for file names as what not.
     */
    if (!pszProgramPath)
    {
        int rc = rtProcInitExePath(g_szrtProcExePath, sizeof(g_szrtProcExePath) - 32);
        if (RT_FAILURE(rc))
            return rc;
    }
    else
    {
        size_t cch = strlen(pszProgramPath);
        Assert(cch > 1);
        AssertMsgReturn(cch < sizeof(g_szrtProcExePath) - 32, ("%zu\n", cch), VERR_BUFFER_OVERFLOW);
        memcpy(g_szrtProcExePath, pszProgramPath, cch + 1);
    }

    /*
     * Parse the name.
     */
    ssize_t offName;
    g_cchrtProcExePath = RTPathParseSimple(g_szrtProcExePath, &g_cchrtProcDir, &offName, NULL);
    g_offrtProcName = offName;
    return VINF_SUCCESS;
}


/**
 * Internal worker which initializes or re-initializes the
 * program path, name and directory globals.
 *
 * @returns IPRT status code.
 * @param   fFlags          Flags, see RTR3INIT_XXX.
 * @param   cArgs           Pointer to the argument count.
 * @param   ppapszArgs      Pointer to the argument vector pointer. NULL
 *                          allowed if @a cArgs is 0.
 */
static int rtR3InitArgv(uint32_t fFlags, int cArgs, char ***ppapszArgs)
{
    NOREF(fFlags);
    if (cArgs)
    {
        AssertPtr(ppapszArgs);
        AssertPtr(*ppapszArgs);
        char **papszOrgArgs = *ppapszArgs;

        /*
         * Normally we should only be asked to convert arguments once.  If we
         * are though, it should be the already convered arguments.
         */
        if (g_crtArgs != -1)
        {
            AssertReturn(   g_crtArgs == cArgs
                         && g_papszrtArgs == papszOrgArgs,
                         VERR_WRONG_ORDER); /* only init once! */
            return VINF_SUCCESS;
        }

        if (!(fFlags & RTR3INIT_FLAGS_UTF8_ARGV))
        {
            /*
             * Convert the arguments.
             */
            char **papszArgs = (char **)RTMemAllocZ((cArgs + 1) * sizeof(char *));
            if (!papszArgs)
                return VERR_NO_MEMORY;

#ifdef RT_OS_WINDOWS
            /* HACK ALERT! Try convert from unicode versions if possible.
               Unfortunately for us, __wargv is only initialized if we have a
               unicode main function.  So, we have to use CommandLineToArgvW to get
               something similar. It should do the same conversion... :-) */
            /** @todo Replace this CommandLineToArgvW call with a call into
             *        getoptargv.cpp so we don't depend on shell32 and an API not present
             *        in NT 3.1.  */
            int    cArgsW     = -1;
            PWSTR *papwszArgs = NULL;
            if (   papszOrgArgs == __argv
                && cArgs        == __argc
                && (papwszArgs = CommandLineToArgvW(GetCommandLineW(), &cArgsW)) != NULL )
            {
                AssertMsg(cArgsW == cArgs, ("%d vs %d\n", cArgsW, cArgs));
                for (int i = 0; i < RT_MIN(cArgs, cArgsW); i++)
                {
                    int rc = papwszArgs[i] != NULL ? RTUtf16ToUtf8Tag(papwszArgs[i], &papszArgs[i], "will-leak:rtR3InitArgv") :
                                                     VERR_GENERAL_FAILURE;
                    if (RT_FAILURE(rc))
                    {
                        while (i--)
                            RTStrFree(papszArgs[i]);
                        RTMemFree(papszArgs);
                        LocalFree(papwszArgs);
                        return rc;
                    }
                }
                LocalFree(papwszArgs);
            }
            else
#endif
            {
                for (int i = 0; i < cArgs; i++)
                {
                    int rc = RTStrCurrentCPToUtf8(&papszArgs[i], papszOrgArgs[i]);
                    if (RT_FAILURE(rc))
                    {
                        while (i--)
                            RTStrFree(papszArgs[i]);
                        RTMemFree(papszArgs);
                        return rc;
                    }
                }
            }

            papszArgs[cArgs] = NULL;

            g_papszrtOrgArgs = papszOrgArgs;
            g_papszrtArgs    = papszArgs;
            g_crtArgs        = cArgs;

            *ppapszArgs = papszArgs;
        }
        else
        {
            /*
             * The arguments are already UTF-8, no conversion needed.
             */
            g_papszrtOrgArgs = papszOrgArgs;
            g_papszrtArgs    = papszOrgArgs;
            g_crtArgs        = cArgs;
        }
    }

    return VINF_SUCCESS;
}


#ifdef IPRT_USE_SIG_CHILD_DUMMY
/**
 * Dummy SIGCHILD handler.
 *
 * Assigned on rtR3Init only when SIGCHILD handler is set SIGIGN or SIGDEF to
 * ensure waitpid works properly for the terminated processes.
 */
static void rtR3SigChildHandler(int iSignal)
{
    NOREF(iSignal);
}
#endif /* IPRT_USE_SIG_CHILD_DUMMY */


/**
 * rtR3Init worker.
 */
static int rtR3InitBody(uint32_t fFlags, int cArgs, char ***ppapszArgs, const char *pszProgramPath)
{
    /*
     * Early native initialization.
     */
    int rc = rtR3InitNativeFirst(fFlags);
    AssertMsgRCReturn(rc, ("rtR3InitNativeFirst failed with %Rrc\n", rc), rc);

    /*
     * Disable error popups.
     */
#if defined(RT_OS_OS2) /** @todo move to private code. */
    DosError(FERR_DISABLEHARDERR);
#endif

    /*
     * Init C runtime locale before we do anything that may end up converting
     * paths or we'll end up using the "C" locale for path conversion.
     */
    setlocale(LC_CTYPE, "");

    /*
     * The Process ID.
     */
#ifdef _MSC_VER
    g_ProcessSelf = _getpid(); /* crappy ansi compiler */
#else
    g_ProcessSelf = getpid();
#endif

    /*
     * Save the init flags.
     */
    g_fInitFlags |= fFlags;

#if !defined(IN_GUEST) && !defined(RT_NO_GIP)
# ifdef VBOX
    /*
     * This MUST be done as the very first thing, before any file is opened.
     * The log is opened on demand, but the first log entries may be caused
     * by rtThreadInit() below.
     */
    const char *pszDisableHostCache = getenv("VBOX_DISABLE_HOST_DISK_CACHE");
    if (    pszDisableHostCache != NULL
        &&  *pszDisableHostCache
        &&  strcmp(pszDisableHostCache, "0") != 0)
    {
        RTFileSetForceFlags(RTFILE_O_WRITE, RTFILE_O_WRITE_THROUGH, 0);
        RTFileSetForceFlags(RTFILE_O_READWRITE, RTFILE_O_WRITE_THROUGH, 0);
    }
# endif  /* VBOX */
#endif /* !IN_GUEST && !RT_NO_GIP */

    /*
     * Thread Thread database and adopt the caller thread as 'main'.
     * This must be done before everything else or else we'll call into threading
     * without having initialized TLS entries and suchlike.
     */
    rc = rtThreadInit();
    AssertMsgRCReturn(rc, ("Failed to initialize threads, rc=%Rrc!\n", rc), rc);

    /*
     * The executable path before SUPLib (windows requirement).
     */
    rc = rtR3InitProgramPath(pszProgramPath);
    AssertLogRelMsgRCReturn(rc, ("Failed to get executable directory path, rc=%Rrc!\n", rc), rc);

#if !defined(IN_GUEST) && !defined(RT_NO_GIP)
    /*
     * Initialize SUPLib here so the GIP can get going as early as possible
     * (improves accuracy for the first client).
     */
    if (fFlags & RTR3INIT_FLAGS_SUPLIB)
    {
        rc = SUPR3Init(NULL);
        AssertMsgRCReturn(rc, ("Failed to initialize the support library, rc=%Rrc!\n", rc), rc);
    }
#endif

    /*
     * Convert arguments.
     */
    rc = rtR3InitArgv(fFlags, cArgs, ppapszArgs);
    AssertLogRelMsgRCReturn(rc, ("Failed to convert the arguments, rc=%Rrc!\n", rc), rc);

#if !defined(IN_GUEST) && !defined(RT_NO_GIP)
    /*
     * The threading is initialized we can safely sleep a bit if GIP
     * needs some time to update itself updating.
     */
    if ((fFlags & RTR3INIT_FLAGS_SUPLIB) && g_pSUPGlobalInfoPage)
    {
        RTThreadSleep(20);
        RTTimeNanoTS();
    }
#endif

    /*
     * Init the program start timestamp TS.
     * Do that here to be sure that the GIP time was properly updated the 1st time.
     */
    g_u64ProgramStartNanoTS = RTTimeNanoTS();

    /*
     * The remainder cannot easily be undone, so it has to go last.
     */

    /* Fork and exit callbacks. */
#if !defined(RT_OS_WINDOWS) && !defined(RT_OS_OS2)
    rc = pthread_atfork(NULL, NULL, rtR3ForkChildCallback);
    AssertMsg(rc == 0, ("%d\n", rc));
#endif
    atexit(rtR3ExitCallback);

#ifdef IPRT_USE_SIG_CHILD_DUMMY
    /*
     * SIGCHLD must not be ignored (that's default), otherwise posix compliant waitpid
     * implementations won't work right.
     */
    for (;;)
    {
        struct sigaction saOld;
        rc = sigaction(SIGCHLD, 0, &saOld);         AssertMsg(rc == 0, ("%d/%d\n", rc, errno));
        if (    rc != 0
            ||  (saOld.sa_flags & SA_SIGINFO)
            || (   saOld.sa_handler != SIG_IGN
                && saOld.sa_handler != SIG_DFL)
           )
            break;

        /* Try install dummy handler. */
        struct sigaction saNew = saOld;
        saNew.sa_flags   = SA_NOCLDSTOP | SA_RESTART;
        saNew.sa_handler = rtR3SigChildHandler;
        rc = sigemptyset(&saNew.sa_mask);           AssertMsg(rc == 0, ("%d/%d\n", rc, errno));
        struct sigaction saOld2;
        rc = sigaction(SIGCHLD, &saNew, &saOld2);   AssertMsg(rc == 0, ("%d/%d\n", rc, errno));
        if (    rc != 0
            ||  (   saOld2.sa_handler == saOld.sa_handler
                 && !(saOld2.sa_flags & SA_SIGINFO))
           )
            break;

        /* Race during dynamic load, restore and try again... */
        sigaction(SIGCHLD, &saOld2, NULL);
        RTThreadYield();
    }
#endif /* IPRT_USE_SIG_CHILD_DUMMY */

#ifdef IPRT_WITH_ALIGNMENT_CHECKS
    /*
     * Enable alignment checks.
     */
    const char *pszAlignmentChecks = getenv("IPRT_ALIGNMENT_CHECKS");
    g_fRTAlignmentChecks = pszAlignmentChecks != NULL
                        && pszAlignmentChecks[0] == '1'
                        && pszAlignmentChecks[1] == '\0';
    if (g_fRTAlignmentChecks)
        IPRT_ALIGNMENT_CHECKS_ENABLE();
#endif

    /*
     * Final native initialization.
     */
    rc = rtR3InitNativeFinal(fFlags);
    AssertMsgRCReturn(rc, ("rtR3InitNativeFinal failed with %Rrc\n", rc), rc);

    return VINF_SUCCESS;
}


/**
 * Internal initialization worker.
 *
 * @returns IPRT status code.
 * @param   fFlags          Flags, see RTR3INIT_XXX.
 * @param   cArgs           Pointer to the argument count.
 * @param   ppapszArgs      Pointer to the argument vector pointer. NULL
 *                          allowed if @a cArgs is 0.
 * @param   pszProgramPath  The program path.  Pass NULL if we're to figure it
 *                          out ourselves.
 */
static int rtR3Init(uint32_t fFlags, int cArgs, char ***ppapszArgs, const char *pszProgramPath)
{
    /* no entry log flow, because prefixes and thread may freak out. */
    Assert(!(fFlags & ~(  RTR3INIT_FLAGS_DLL
                        | RTR3INIT_FLAGS_SUPLIB
                        | RTR3INIT_FLAGS_UNOBTRUSIVE
                        | RTR3INIT_FLAGS_UTF8_ARGV
                        | RTR3INIT_FLAGS_STANDALONE_APP)));
    Assert(!(fFlags & RTR3INIT_FLAGS_DLL) || cArgs == 0);

    /*
     * Do reference counting, only initialize the first time around.
     *
     * We are ASSUMING that nobody will be able to race RTR3Init* calls when the
     * first one, the real init, is running (second assertion).
     */
    int32_t cUsers = ASMAtomicIncS32(&g_cUsers);
    if (cUsers != 1)
    {
        AssertMsg(cUsers > 1, ("%d\n", cUsers));
        Assert(!g_fInitializing);
#if !defined(IN_GUEST) && !defined(RT_NO_GIP)
        if (fFlags & RTR3INIT_FLAGS_SUPLIB)
        {
            SUPR3Init(NULL);
            g_fInitFlags |= RTR3INIT_FLAGS_SUPLIB;
        }
#endif
        g_fInitFlags |= fFlags & RTR3INIT_FLAGS_UTF8_ARGV;

        if (   !(fFlags      & RTR3INIT_FLAGS_UNOBTRUSIVE)
            && (g_fInitFlags & RTR3INIT_FLAGS_UNOBTRUSIVE))
        {
            g_fInitFlags &= ~RTR3INIT_FLAGS_UNOBTRUSIVE;
            g_fInitFlags |= fFlags & RTR3INIT_FLAGS_STANDALONE_APP;
            rtR3InitNativeObtrusive(g_fInitFlags | fFlags);
            rtThreadReInitObtrusive();
        }
        else
            Assert(!(fFlags & RTR3INIT_FLAGS_STANDALONE_APP) || (g_fInitFlags & RTR3INIT_FLAGS_STANDALONE_APP));

        int rc = VINF_SUCCESS;
        if (pszProgramPath)
            rc = rtR3InitProgramPath(pszProgramPath);
        if (RT_SUCCESS(rc))
            rc = rtR3InitArgv(fFlags, cArgs, ppapszArgs);
        return rc;
    }
    ASMAtomicWriteBool(&g_fInitializing, true);

    /*
     * Do the initialization.
     */
    int rc = rtR3InitBody(fFlags, cArgs, ppapszArgs, pszProgramPath);
    if (RT_FAILURE(rc))
    {
        /* failure */
        ASMAtomicWriteBool(&g_fInitializing, false);
        ASMAtomicDecS32(&g_cUsers);
        return rc;
    }

    /* success */
    LogFlow(("rtR3Init: returns VINF_SUCCESS\n"));
    ASMAtomicWriteBool(&g_fInitializing, false);
    return VINF_SUCCESS;
}


RTR3DECL(int) RTR3InitExe(int cArgs, char ***ppapszArgs, uint32_t fFlags)
{
    Assert(!(fFlags & RTR3INIT_FLAGS_DLL));
    return rtR3Init(fFlags, cArgs, ppapszArgs, NULL);
}


RTR3DECL(int) RTR3InitExeNoArguments(uint32_t fFlags)
{
    Assert(!(fFlags & RTR3INIT_FLAGS_DLL));
    return rtR3Init(fFlags, 0, NULL, NULL);
}


RTR3DECL(int) RTR3InitDll(uint32_t fFlags)
{
    Assert(!(fFlags & RTR3INIT_FLAGS_DLL));
    return rtR3Init(fFlags | RTR3INIT_FLAGS_DLL, 0, NULL, NULL);
}


RTR3DECL(int) RTR3InitEx(uint32_t iVersion, uint32_t fFlags, int cArgs, char ***ppapszArgs, const char *pszProgramPath)
{
    AssertReturn(iVersion == RTR3INIT_VER_CUR, VERR_NOT_SUPPORTED);
    return rtR3Init(fFlags, cArgs, ppapszArgs, pszProgramPath);
}


RTR3DECL(bool) RTR3InitIsInitialized(void)
{
    return g_cUsers >= 1 && !g_fInitializing;
}


RTR3DECL(bool) RTR3InitIsUnobtrusive(void)
{
    return RT_BOOL(g_fInitFlags & RTR3INIT_FLAGS_UNOBTRUSIVE);
}


#if 0 /** @todo implement RTR3Term. */
RTR3DECL(void) RTR3Term(void)
{
}
#endif

