path_converter.cpp

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#include "path_converter.h"
 
#include <windows.h>
 
#include "ntddk.h"
#pragma comment(lib, "Ntdll.lib")
 
#include <shlwapi.h>
#pragma comment (lib, "shlwapi.lib")
 
#include <iostream>
#include <string>
#include <locale>
#include <codecvt>
 
#include "path_util.h"
 
#define LONG_PATH_PREFIX "\\\\?\\"
#define GLOBALROOT_NAME "GLOBALROOT"
 
char g_System32Path[MAX_PATH] = { 0 }; //= "C:\\Windows\\system32";
char g_Syswow64Path[MAX_PATH] = { 0 }; //= "C:\\Windows\\SysWOW64";
 
namespace pesieve {
    namespace util {
 
        void init_syspaths()
        {
            if (!g_System32Path[0]) {
                memset(g_System32Path, 0, MAX_PATH);
                ExpandEnvironmentStringsA("%SystemRoot%\\system32", g_System32Path, MAX_PATH);
            }
            if (!g_Syswow64Path[0]) {
                memset(g_Syswow64Path, 0, MAX_PATH);
                ExpandEnvironmentStringsA("%SystemRoot%\\SysWoW64", g_Syswow64Path, MAX_PATH);
            }
        }
 
        HANDLE nt_create_file(PCWSTR filePath)
        {
            HANDLE hFile;
            OBJECT_ATTRIBUTES objAttribs = { 0 };
 
            UNICODE_STRING unicodeString;
            RtlInitUnicodeString(&unicodeString, filePath);
 
            InitializeObjectAttributes(&objAttribs, &unicodeString, OBJ_CASE_INSENSITIVE, NULL, NULL);
 
            const int allocSize = 2048;
            LARGE_INTEGER largeInteger;
            largeInteger.QuadPart = allocSize;
 
            IO_STATUS_BLOCK ioStatusBlock = { 0 };
            NTSTATUS status = NtCreateFile(&hFile,
                STANDARD_RIGHTS_READ,
                &objAttribs,
                &ioStatusBlock,
                &largeInteger,
                FILE_ATTRIBUTE_NORMAL,
                FILE_SHARE_READ,
                FILE_OPEN,
                FILE_NON_DIRECTORY_FILE,
                NULL,
                0
            );
            if (status != STATUS_SUCCESS) {
                std::wcerr << "Cannot open file: " << filePath << ". Error: " << std::hex << status << std::endl;
                return nullptr;
            }
            return hFile;
        }
 
        std::string nt_retrieve_file_path(HANDLE hFile)
        {
            IO_STATUS_BLOCK status_block = { 0 };
 
            struct MY_FILE_NAME_INFORMATION {
                ULONG FileNameLength;
                WCHAR FileName[MAX_PATH];
            } name_info;
 
            memset(&name_info, 0, sizeof(MY_FILE_NAME_INFORMATION));
 
            NTSTATUS status = ZwQueryInformationFile(hFile, &status_block, &name_info, sizeof(MY_FILE_NAME_INFORMATION), FileNameInformation);
            if (status != STATUS_SUCCESS) {
                return "";
            }
            std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
            std::string my_string = converter.to_bytes(name_info.FileName);
 
            my_string = get_system_drive() + my_string;
            return my_string;
        }
 
        bool is_relative(const char *path, size_t path_len)
        {
            if (path_len < 2) {
                return true;
            }
            // i.e. "c:\"
            if (path[1] == ':') {
                return false;
            }
            // i.e. "\\path1\" or "\\?\UNC\"
            if (path[0] == '\\' && path[1] == '\\') {
                return false;
            }
            return true;
        }
 
        bool is_disk_relative(const char *path, size_t path_len)
        {
            if (path_len < 2) {
                return true;
            }
            //check format:
            if ((path[0] >= 'a' && path[0] <= 'z')
                || (path[0] >= 'A' && path[0] <= 'Z'))
            {
                if (path[1] == ':') {
                    // format i.e: C:\...
                    return true;
                }
            }
            return false;
        }
 
        std::string remap_to_drive_letter(const std::string &full_path)
        {
            size_t full_path_size = full_path.length();
            if (full_path_size == 0) {
                return full_path;
            }
 
            DWORD drives_bitmask = GetLogicalDrives();
            //std::cout << "Drives: " << std::hex << drives_bitmask << std::endl;
 
            for (DWORD i = 0; i < 32; i += 1, drives_bitmask >>= 1) {
                if ((drives_bitmask & 1) == 1) {
                    char letter[] = "?:";
                    letter[0] = 'A' + (char)i;
                    //std::cout << "Drive: " << letter << std::endl;
                    char out_path[MAX_PATH] = { 0 };
                    if (!QueryDosDeviceA(letter, out_path, MAX_PATH)) {
                        return full_path;
                    }
                    //QueryDosDeviceA returns all possible mappings pointing to this drive letter, divided by a delimiter: ";"
                    //sometimes one device letter is mapped to several paths
                    // i.e. "\Device\VBoxMiniRdr\;E:\vboxsrv\vm_shared"
                    const char delim[] = ";";
                    char *next_token = nullptr;
 
                    char * pch = strtok_s(out_path, delim, &next_token);
                    while (pch != nullptr) {
                        // check if the current path starts from any of the mapped paths
                        std::size_t found = full_path.find(pch);
                        if (found != std::string::npos && found == 0) {
                            size_t dir_len = strlen(pch);
                            //if so, cut out the mappining path/device path and replace it with a drive letter
                            std::string str2 = full_path.substr(dir_len, full_path_size);
                            if (str2[0] != '/' && str2[0] != '\\') {
                                str2 = "\\" + str2;
                            }
                            return letter + str2;
                        }
                        pch = strtok_s(nullptr, delim, &next_token);
                    }
                }
            }
            return full_path;
        }
 
        std::string relative_to_absolute_path(std::string path)
        {
            if (is_relative(path.c_str(), path.length())) {
                char current_dir[MAX_PATH] = { 0 };
                GetCurrentDirectoryA(MAX_PATH, current_dir);
                path = std::string(current_dir) + "\\" + path;
            }
            char out_path[MAX_PATH] = { 0 };
            PathCanonicalizeA(out_path, path.c_str());
            return std::string(out_path);
        }
 
        std::string replace_char(std::string &str, char ch1, char ch2) {
            for (size_t i = 0; i < str.length(); ++i) {
                if (str[i] == ch1)
                    str[i] = ch2;
            }
            return str;
        }
    };
};
 
bool pesieve::util::convert_to_wow64_path(char *szModName)
{
    init_syspaths();
    if (!get_subpath_ptr(szModName, g_System32Path)) {
        return false;
    }
    size_t sysPathLen = strlen(g_Syswow64Path);
    memcpy(szModName, g_Syswow64Path, sysPathLen);
    return true;
}
 
std::string pesieve::util::convert_to_win32_path(const std::string &path)
{
    std::string stripped_path = strip_prefix(path, LONG_PATH_PREFIX);
    if (stripped_path.length() < 3) {
        return "";
    }
    //check format:
    if (is_disk_relative(stripped_path.c_str(), stripped_path.length())) {
        return stripped_path;
    }
    stripped_path = strip_prefix(stripped_path, GLOBALROOT_NAME);
    const char *szModName = stripped_path.c_str();
    std::wstring unicode_name(szModName, szModName + strlen(szModName));
    HANDLE hFile = nt_create_file(unicode_name.c_str());
    if (hFile == nullptr) {
        return "";
    }
    std::string my_path = nt_retrieve_file_path(hFile);
    CloseHandle(hFile);
    return my_path;
}
 
std::string pesieve::util::device_path_to_win32_path(const std::string &full_path)
{
    std::string path = full_path;
    //sometimes mapping can be recursive, so resolve it till the root
    do {
        std::string remapped_path = remap_to_drive_letter(path);
        if (remapped_path == path) break;
        path = remapped_path;
    } while (true);
    return path;
}
 
bool is_device_path(const std::string &path)
{
    const std::string device_path = "\\Device\\";
    if (path.length() < device_path.length() || path[0] !='\\') {
        return false;
    }
    if (path.compare(0, device_path.length(), device_path) == 0){
        return true;
    }
    return false;
}
 
std::string pesieve::util::expand_path(const std::string &path)
{
    std::string basic_path = pesieve::util::device_path_to_win32_path(path);
    if (is_device_path(basic_path)) {
        // Could not normalize it: it is still a device path. Return as is.
        return path;
    }
    // normalize path sepators: use '/' not '\'
    replace_char(basic_path, '/', '\\');
 
    std::string abs_path = relative_to_absolute_path(basic_path);
    
    char filename[MAX_PATH] = { 0 };
    if (GetLongPathNameA(abs_path.c_str(), filename, MAX_PATH) == 0) {
        size_t len = abs_path.length();
        if (len > MAX_PATH) len = MAX_PATH;
        //if could not retrieve, process what you have:
        memcpy(filename, abs_path.c_str(), len);
    }
    return strip_prefix(filename, LONG_PATH_PREFIX);
}