goldberg_emulator/dll/wrap.cpp
2020-07-16 11:56:24 +02:00

567 lines
18 KiB
C++

/* Copyright (C) 2019 Mr Goldberg
This file is part of the Goldberg Emulator
The Goldberg Emulator 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 3 of the License, or (at your option) any later version.
The Goldberg Emulator 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 the Goldberg Emulator; if not, see
<http://www.gnu.org/licenses/>. */
#if defined(WIN64) || defined(_WIN64) || defined(__MINGW64__)
#define __WINDOWS_64__
#elif defined(WIN32) || defined(_WIN32) || defined(__MINGW32__)
#define __WINDOWS_32__
#endif
#if defined(__WINDOWS_32__) || defined(__WINDOWS_64__)
// Nothing to be done here
#else
#define STEAM_API_FUNCTIONS_IMPL
#include "base.h"
#include "dll.h"
#define PATH_SEPARATOR_CHAR '/'
#define STEAM_PATH_CACHE_SIZE 4096
const char *STEAM_PATH;
size_t STEAM_PATH_SIZE;
// Returns a '/' terminated absolute path to the steam folder in user's home,
// root is returned if env home is not set
const char *get_steam_path()
{
char *home_path = getenv("HOME");
char steam_path[STEAM_PATH_CACHE_SIZE];
char *steam_realpath = nullptr;
// Build steam_path from home
int required_size = snprintf(steam_path, STEAM_PATH_CACHE_SIZE, "%s/.steam/steam", home_path);
// Allocate more space for steam_path if needed (required_size does not count terminator)
if (required_size > 0 && required_size >= STEAM_PATH_CACHE_SIZE) {
char *large_steam_path = (char *)malloc(sizeof(char) * (required_size + 1));
int check_size = snprintf(large_steam_path, required_size + 1, "%s/.steam/steam", home_path);
// Check that path fits this time
if (check_size == required_size) {
steam_realpath = realpath(large_steam_path, nullptr);
}
free(large_steam_path);
} else {
steam_realpath = realpath(steam_path, nullptr);
}
// Terminate path with a file separator
if (steam_realpath && *steam_realpath) {
size_t path_size = strlen(steam_realpath);
if (steam_realpath[path_size - 1] != PATH_SEPARATOR_CHAR) {
steam_realpath = (char *)realloc(steam_realpath, path_size + 2);
steam_realpath[path_size] = PATH_SEPARATOR_CHAR;
steam_realpath[path_size + 1] = 0;
}
} else {
// Failsafe to root
steam_realpath = strdup("/");
}
return steam_realpath;
}
// Fixes given path by navigating filesystem and lowering case to match
// existing entries on disk
bool match_path(char *path, int start, bool accept_same_case)
{
if (!path[start + 1]) {
return true;
}
// Snap to the next separator in path
int separator = start + 1;
while (path[separator] != PATH_SEPARATOR_CHAR && path[separator]) {
separator++;
}
bool is_last_component = path[separator] != PATH_SEPARATOR_CHAR;
char stored_char = path[separator];
path[separator] = 0;
bool path_accessible = access(path, F_OK) == 0;
path[separator] = stored_char;
if (!path_accessible || (!is_last_component && !match_path(path, separator, accept_same_case))) {
DIR *current_directory = nullptr;
int component = start + 1;
if (start) {
stored_char = path[start];
path[start] = 0;
current_directory = opendir(path);
path[start] = stored_char;
component = start + 1;
} else {
if (*path == PATH_SEPARATOR_CHAR) {
component = start + 1;
current_directory = opendir("/");
} else {
component = start;
current_directory = opendir(".");
}
}
// 0123456789012345678901234567890123456789
// path = /this/is/a/sample/path/to/file.txt
// ^^ ^
// ab c
// a. start = 10
// b. component = 11
// c. separator = 17
// current_directory = /this/is/a/
if (current_directory) {
dirent64 *entry = (dirent64 *)readdir64(current_directory);
while (entry) {
const char *entry_name = entry->d_name;
stored_char = path[separator];
path[separator] = 0;
// Fix current component if entry with similar name exists
if (!strcasecmp(&path[component], entry_name)) {
bool case_differs = strcmp(&path[component], entry_name) != 0;
path[separator] = stored_char;
if (case_differs) {
char *iterator = &path[component];
// Replace with entry name
while (*entry_name != PATH_SEPARATOR_CHAR && *entry_name) {
*(iterator++) = *(entry_name++);
}
// Fix next component
if (is_last_component || match_path(path, separator, accept_same_case)) {
closedir(current_directory);
return true;
}
}
} else {
path[separator] = stored_char;
}
entry = (dirent64 *)readdir64(current_directory);
}
}
if (current_directory) {
closedir(current_directory);
}
return accept_same_case && is_last_component;
}
return true;
}
// Tries to convert the given path to the preferred lower-cased version
const char *lowercase_path(const char *path, bool accept_same_case, bool stop_at_separator)
{
std::locale loc;
char *path_lowercased = nullptr;
if (path && *path) {
// If file does not exist
if (access(path, F_OK)) {
// Make a copy of the path on which to work on
path_lowercased = strdup(path);
if (!path_lowercased) {
return nullptr;
}
// Load steam path if not done already
if (!STEAM_PATH) {
STEAM_PATH = get_steam_path();
STEAM_PATH_SIZE = strlen(STEAM_PATH);
}
char *lowercase_iterator = path_lowercased;
// Lowercase whole steam path if possible
bool has_steam_root = false;
if (!strncasecmp(path_lowercased, STEAM_PATH, STEAM_PATH_SIZE)) {
memcpy(path_lowercased, STEAM_PATH, STEAM_PATH_SIZE);
lowercase_iterator = &path_lowercased[STEAM_PATH_SIZE - 1];
has_steam_root = true;
}
// Lowercase rest of the path
char *iterator = lowercase_iterator;
while ((!stop_at_separator || *iterator != PATH_SEPARATOR_CHAR) && *iterator) {
*iterator = std::tolower(*iterator, loc);
iterator++;
}
// Check if we can access the lowered-case path
int error = access(path_lowercased, F_OK);
if (!error) {
// The new path is valid
return path_lowercased;
} else {
if (accept_same_case) {
const char *name_iterator = &path[lowercase_iterator - path_lowercased];
while (*lowercase_iterator) {
*(lowercase_iterator++) = *(name_iterator++);
}
}
// Retry accesing the file again and tweak the path if needed
if (match_path(path_lowercased, has_steam_root? STEAM_PATH_SIZE - 1 : 0, accept_same_case)) {
return path_lowercased;
}
}
}
}
return path;
}
STEAMAPI_API FILE *__wrap_freopen(const char *path, const char *modes, FILE *stream)
{
bool is_writable = strpbrk(modes, "wa+") != 0;
const char *path_lowercased = lowercase_path(path, is_writable, true);
FILE *result = freopen(path_lowercased, modes, stream);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API FILE *__wrap_fopen(const char *path, const char *modes)
{
bool is_writable = strpbrk(modes, "wa+") != 0;
const char *path_lowercased = lowercase_path(path, is_writable, true);
FILE *result = fopen(path_lowercased, modes);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API FILE *__wrap_fopen64(const char *path, const char *modes)
{
bool is_writable = strpbrk(modes, "wa+") != 0;
const char *path_lowercased = lowercase_path(path, is_writable, true);
FILE *result = fopen64(path_lowercased, modes);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_open(const char *path, int flags, mode_t mode)
{
bool is_writable = flags & (X_OK | W_OK);
const char *path_lowercased = lowercase_path(path, is_writable, true);
int result = open(path_lowercased, flags, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_open64(const char *path, int flags, mode_t mode)
{
bool is_writable = flags & (X_OK | W_OK);
const char *path_lowercased = lowercase_path(path, is_writable, true);
int result = open64(path_lowercased, flags, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_access(const char *path, int mode)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = access(path_lowercased, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap___xstat(int ver, const char * path, struct stat * stat_buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = __xstat(ver, path_lowercased, stat_buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_stat(const char * path, struct stat * stat_buf)
{
return __wrap___xstat(3, path, stat_buf);
}
STEAMAPI_API int __wrap___lxstat(int ver, const char * path, struct stat * stat_buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = __lxstat(ver, path_lowercased, stat_buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_lstat(const char * path, struct stat * stat_buf)
{
return __wrap___lxstat(3, path, stat_buf);
}
STEAMAPI_API int __wrap_scandir(const char *path, struct dirent ***namelist, int (*sel)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **))
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = scandir(path_lowercased, namelist, sel, compar);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_scandir64(const char *path, struct dirent64 ***namelist, int (*sel)(const struct dirent64 *), int (*compar)(const struct dirent64 **, const struct dirent64 **))
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = scandir64(path_lowercased, namelist, sel, compar);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API DIR *__wrap_opendir(const char *path)
{
const char *path_lowercased = lowercase_path(path, false, false);
DIR *result = opendir(path_lowercased);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap___xstat64(int ver, const char *path, struct stat64 *stat_buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = __xstat64(ver, path_lowercased, stat_buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap___lxstat64(int ver, const char *path, struct stat64 *stat_buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = __lxstat64(ver, path_lowercased, stat_buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_statvfs(const char *path, struct statvfs *buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = statvfs(path_lowercased, buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_statvfs64(const char *path, struct statvfs64 *buf)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = statvfs64(path_lowercased, buf);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_chmod(const char *path, mode_t mode)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = chmod(path_lowercased, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_chown(const char *path, uid_t owner, gid_t group)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = chown(path_lowercased, owner, group);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_lchown(const char *path, uid_t owner, gid_t group)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = lchown(path_lowercased, owner, group);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_symlink(const char *path1, const char *path2)
{
const char *path_lowercased1 = lowercase_path(path1, true, true);
const char *path_lowercased2 = lowercase_path(path2, false, false);
int result = symlink(path_lowercased1, path_lowercased2);
if (path_lowercased1 != path1) {
free((void *)path_lowercased1);
}
if (path_lowercased2 != path2) {
free((void *)path_lowercased2);
}
return result;
}
STEAMAPI_API int __wrap_link(const char *path1, const char *path2)
{
const char *path_lowercased1 = lowercase_path(path1, true, true);
const char *path_lowercased2 = lowercase_path(path2, false, false);
int result = link(path_lowercased1, path_lowercased2);
if (path_lowercased1 != path1) {
free((void *)path_lowercased1);
}
if (path_lowercased2 != path2) {
free((void *)path_lowercased2);
}
return result;
}
STEAMAPI_API int __wrap_mknod(const char *path, mode_t mode, dev_t dev)
{
const char *path_lowercased = lowercase_path(path, true, true);
int result = __xmknod(1, path_lowercased, mode, &dev);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_mount(const char *source, const char *target, const char *filesystemtype, unsigned long mountflags, const void *data)
{
const char *source_lowercased = lowercase_path(source, false, false);
const char *target_lowercased = lowercase_path(target, false, false);
int result = mount(source_lowercased, target_lowercased, filesystemtype, mountflags, data);
if (source_lowercased != source) {
free((void *)source_lowercased);
}
if (target_lowercased != target) {
free((void *)target_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_unlink(const char *path)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = unlink(path);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_mkfifo(const char *path, mode_t mode)
{
const char *path_lowercased = lowercase_path(path, true, true);
int result = mkfifo(path, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_rename(const char *old_name, const char *new_name)
{
const char *old_name_lowercased = lowercase_path(old_name, true, true);
const char *new_name_lowercased = lowercase_path(new_name, false, false);
int result = rename(old_name_lowercased, new_name_lowercased);
if (old_name_lowercased != old_name) {
free((void *)old_name_lowercased);
}
if (new_name_lowercased != new_name) {
free((void *)new_name_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_utime(const char *path, const struct utimbuf *times)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = utime(path_lowercased, times);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_utimes(const char *path, const struct timeval times[2])
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = utimes(path_lowercased, times);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_mkdir(const char *path, mode_t mode)
{
const char *path_lowercased = lowercase_path(path, true, true);
int result = mkdir(path_lowercased, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API int __wrap_rmdir(const char *path)
{
const char *path_lowercased = lowercase_path(path, false, false);
int result = rmdir(path_lowercased);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API void *__wrap_dlopen(const char *path, int mode)
{
const char *path_lowercased = lowercase_path(path, false, false);
void * result = dlopen(path_lowercased, mode);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
STEAMAPI_API void *__wrap_dlmopen(Lmid_t lmid, const char *path, int flags)
{
const char *path_lowercased = lowercase_path(path, false, false);
void * result = dlmopen(lmid, path_lowercased, flags);
if (path_lowercased != path) {
free((void *)path_lowercased);
}
return result;
}
#endif