/*
 * Emulator initialisation code
 *
 * Copyright 2000 Alexandre Julliard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include "config.h"
#include "wine/port.h"

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif
#ifdef HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include "wine/library.h"
#include "main.h"

extern char **environ;

/* the preloader will set this variable */
const struct wine_preload_info *wine_main_preload_info = NULL;

/***********************************************************************
 *           check_command_line
 *
 * Check if command line is one that needs to be handled specially.
 */
static void check_command_line( int argc, char *argv[] )
{
    static const char usage[] =
        "Usage: wine PROGRAM [ARGUMENTS...]   Run the specified program\n"
        "       wine --help                   Display this help and exit\n"
        "       wine --version                Output version information and exit";

    if (argc <= 1)
    {
        fprintf( stderr, "%s\n", usage );
        exit(1);
    }
    if (!strcmp( argv[1], "--help" ))
    {
        printf( "%s\n", usage );
        exit(0);
    }
    if (!strcmp( argv[1], "--version" ))
    {
        printf( "%s\n", wine_get_build_id() );
        exit(0);
    }
}


#ifdef __ANDROID__

static int pre_exec(void)
{
#if defined(__i386__) || defined(__x86_64__)
    return 1;  /* we have a preloader */
#else
    return 0;  /* no exec needed */
#endif
}

#elif defined(__linux__) && (defined(__i386__) || defined(__arm__))

static void check_vmsplit( void *stack )
{
    if (stack < (void *)0x80000000)
    {
        /* if the stack is below 0x80000000, assume we can safely try a munmap there */
        if (munmap( (void *)0x80000000, 1 ) == -1 && errno == EINVAL)
            fprintf( stderr,
                     "Warning: memory above 0x80000000 doesn't seem to be accessible.\n"
                     "Wine requires a 3G/1G user/kernel memory split to work properly.\n" );
    }
}

static void set_max_limit( int limit )
{
    struct rlimit rlimit;

    if (!getrlimit( limit, &rlimit ))
    {
        rlimit.rlim_cur = rlimit.rlim_max;
        setrlimit( limit, &rlimit );
    }
}

static int pre_exec(void)
{
    int temp;

    check_vmsplit( &temp );
    set_max_limit( RLIMIT_AS );
#ifdef __i386__
    return 1;  /* we have a preloader on x86 */
#else
    return 0;
#endif
}

#elif defined(__linux__) && (defined(__x86_64__) || defined(__aarch64__))

static int pre_exec(void)
{
    return 1;  /* we have a preloader on x86-64/arm64 */
}

#elif defined(__APPLE__) && (defined(__i386__) || defined(__x86_64__))

static int pre_exec(void)
{
    return 1;  /* we have a preloader */
}

#elif (defined(__FreeBSD__) || defined (__FreeBSD_kernel__) || defined(__DragonFly__))

static int pre_exec(void)
{
    struct rlimit rl;

    rl.rlim_cur = 0x02000000;
    rl.rlim_max = 0x02000000;
    setrlimit( RLIMIT_DATA, &rl );
    return 1;
}

#else

static int pre_exec(void)
{
    return 0;  /* no exec needed */
}

#endif


/* canonicalize path and return its directory name */
static char *realpath_dirname( const char *name )
{
    char *p, *fullpath = realpath( name, NULL );

    if (fullpath)
    {
        p = strrchr( fullpath, '/' );
        if (p == fullpath) p++;
        if (p) *p = 0;
    }
    return fullpath;
}

/* if string ends with tail, remove it */
static char *remove_tail( const char *str, const char *tail )
{
    size_t len = strlen( str );
    size_t tail_len = strlen( tail );
    char *ret;

    if (len < tail_len) return NULL;
    if (strcmp( str + len - tail_len, tail )) return NULL;
    ret = malloc( len - tail_len + 1 );
    memcpy( ret, str, len - tail_len );
    ret[len - tail_len] = 0;
    return ret;
}

/* build a path from the specified dir and name */
static char *build_path( const char *dir, const char *name )
{
    size_t len = strlen( dir );
    char *ret = malloc( len + strlen( name ) + 2 );

    memcpy( ret, dir, len );
    if (len && ret[len - 1] != '/') ret[len++] = '/';
    strcpy( ret + len, name );
    return ret;
}

static const char *get_self_exe( char *argv0 )
{
#if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__)
    return "/proc/self/exe";
#elif defined (__FreeBSD__) || defined(__DragonFly__)
    return "/proc/curproc/file";
#else
    if (!strchr( argv0, '/' )) /* search in PATH */
    {
        char *p, *path = getenv( "PATH" );

        if (!path || !(path = strdup(path))) return NULL;
        for (p = strtok( path, ":" ); p; p = strtok( NULL, ":" ))
        {
            char *name = build_path( p, argv0 );
            int found = !access( name, X_OK );
            free( name );
            if (found) break;
        }
        if (p) p = strdup( p );
        free( path );
        return p;
    }
    return argv0;
#endif
}

static void *try_dlopen( const char *dir, const char *name )
{
    char *path = build_path( dir, name );
    void *handle = dlopen( path, RTLD_NOW );
    free( path );
    return handle;
}

static void *load_ntdll( char *argv0 )
{
    const char *self = get_self_exe( argv0 );
    char *path, *p;
    void *handle = NULL;

    if (self && ((path = realpath_dirname( self ))))
    {
        if ((p = remove_tail( path, "/loader" )))
        {
            handle = try_dlopen( p, "dlls/ntdll/ntdll.so" );
            free( p );
        }
        else handle = try_dlopen( path, BIN_TO_DLLDIR "/ntdll.so" );
        free( path );
    }

    if (!handle && (path = getenv( "WINEDLLPATH" )))
    {
        path = strdup( path );
        for (p = strtok( path, ":" ); p; p = strtok( NULL, ":" ))
        {
            handle = try_dlopen( p, "ntdll.so" );
            if (handle) break;
        }
        free( path );
    }

    if (!handle && !self) handle = try_dlopen( DLLDIR, "ntdll.so" );

    return handle;
}


/**********************************************************************
 *           main
 */
int main( int argc, char *argv[] )
{
    char error[1024];
    int i;
    void *handle;

    if ((handle = load_ntdll( argv[0] )))
    {
        void (*init_func)(int, char **, char **) = dlsym( handle, "__wine_main" );
        if (init_func) init_func( argc, argv, environ );
        fprintf( stderr, "wine: __wine_main function not found in ntdll.so\n" );
        exit(1);
    }

    if (!getenv( "WINELOADERNOEXEC" ))  /* first time around */
    {
        static char noexec[] = "WINELOADERNOEXEC=1";

        putenv( noexec );
        check_command_line( argc, argv );
        if (pre_exec())
        {
            wine_init_argv0_path( argv[0] );
            wine_exec_wine_binary( NULL, argv, getenv( "WINELOADER" ));
            fprintf( stderr, "wine: could not exec the wine loader\n" );
            exit(1);
        }
    }

    if (wine_main_preload_info)
    {
        for (i = 0; wine_main_preload_info[i].size; i++)
            wine_mmap_add_reserved_area( wine_main_preload_info[i].addr, wine_main_preload_info[i].size );
    }

    wine_init( argc, argv, error, sizeof(error) );
    fprintf( stderr, "wine: failed to initialize: %s\n", error );
    exit(1);
}