win32_dirent.c

/*
MIT License
Copyright (c) 2019 win32ports
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
// Source: https://github.com/win32ports/dirent_h
 
#ifdef _WIN32
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
 
#include <ctype.h>  // for isdigit
#include <errno.h>
#include <shlwapi.h>  // for PathIsRelativeW
#include <stdint.h>
#include <stdlib.h>  // for malloc, free
#include <string.h>  // for memcpy, memset
#include <sys/types.h>
#include <windows.h>   // for Windows API
#include <winioctl.h>  // for FSCTL_GET_REPARSE_POINT
 
#ifdef _MSC_VER
#pragma comment(lib, "Shlwapi.lib")
#endif
 
#include <wincrypt.h>                 // For HCRYPTPROV, CryptAcquireContextW, CryptGenRandom, etc.
#pragma comment(lib, "advapi32.lib")  // Link against the Crypto API library
 
/*
 * Constants and Macros
 */
 
#ifndef NAME_MAX
#define NAME_MAX 260
#endif /* NAME_MAX */
 
#ifndef DT_UNKNOWN
#define DT_UNKNOWN 0
#endif /* DT_UNKNOWN */
 
#ifndef DT_FIFO
#define DT_FIFO 1
#endif /* DT_FIFO */
 
#ifndef DT_CHR
#define DT_CHR 2
#endif /* DT_CHR */
 
#ifndef DT_DIR
#define DT_DIR 4
#endif /* DT_DIR */
 
#ifndef DT_BLK
#define DT_BLK 6
#endif /* DT_BLK */
 
#ifndef DT_REG
#define DT_REG 8
#endif /* DT_REG */
 
#ifndef DT_LNK
#define DT_LNK 10
#endif /* DT_LNK */
 
#ifndef DT_SOCK
#define DT_SOCK 12
#endif /* DT_SOCK */
 
#ifndef DT_WHT
#define DT_WHT 14
#endif /* DT_WHT */
 
#ifndef NTFS_MAX_PATH
#define NTFS_MAX_PATH 32768
#endif /* NTFS_MAX_PATH */
 
#ifndef MAXIMUM_REPARSE_DATA_BUFFER_SIZE
#define MAXIMUM_REPARSE_DATA_BUFFER_SIZE 16384
#endif /* MAXIMUM_REPARSE_DATA_BUFFER_SIZE */
 
#ifndef IO_REPARSE_TAG_SYMLINK
#define IO_REPARSE_TAG_SYMLINK 0xA000000C
#endif /* IO_REPARSE_TAG_SYMLINK */
 
#ifndef FILE_NAME_NORMALIZED
#define FILE_NAME_NORMALIZED 0
#endif /* FILE_NAME_NORMALIZED */
 
typedef void* DIR;
 
typedef struct ino_t {
    unsigned long long serial;
    unsigned char fileid[16];
} __ino_t;
 
struct dirent {
    __ino_t d_ino;           /* File serial number */
    off_t d_off;             /* Offset to the next dirent */
    unsigned short d_reclen; /* Length of this record */
    unsigned char d_namelen; /* Length of the name */
    unsigned char d_type;    /* Type of file (DT_*) */
    char d_name[NAME_MAX];   /* Null-terminated filename */
};
 
struct __dir {
    struct dirent* entries;
    intptr_t fd;
    long int count;
    long int index;
};
 
int closedir(DIR* dirp) {
    struct __dir* data = NULL;
    if (!dirp) {
        errno = EBADF;
        return -1;
    }
    data = (struct __dir*)dirp;
    CloseHandle((HANDLE)data->fd);
    free(data->entries);
    free(data);
    return 0;
}
 
static void __seterrno(int value) {
#ifdef _MSC_VER
    _set_errno(value);
#else  /* _MSC_VER */
    errno = value;
#endif /* _MSC_VER */
}
 
static int __islink(const wchar_t* name, char* buffer) {
    DWORD io_result = 0;
    DWORD bytes_returned = 0;
    HANDLE hFile =
        CreateFileW(name, 0, 0, NULL, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, 0);
    if (hFile == INVALID_HANDLE_VALUE) return 0;
 
    io_result = (DWORD)DeviceIoControl(hFile, FSCTL_GET_REPARSE_POINT, NULL, 0, buffer,
                                       MAXIMUM_REPARSE_DATA_BUFFER_SIZE, &bytes_returned, NULL);
 
    CloseHandle(hFile);
 
    if (io_result == 0) return 0;
 
    return ((REPARSE_GUID_DATA_BUFFER*)buffer)->ReparseTag == IO_REPARSE_TAG_SYMLINK;
}
 
#pragma pack(push, 1)
 
typedef struct dirent_FILE_ID_128 {
    BYTE Identifier[16];
} dirent_FILE_ID_128;
 
typedef struct _dirent_FILE_ID_INFO {
    ULONGLONG VolumeSerialNumber;
    dirent_FILE_ID_128 FileId;
} dirent_FILE_ID_INFO;
 
#pragma pack(pop)
 
typedef enum dirent_FILE_INFO_BY_HANDLE_CLASS { dirent_FileIdInfo = 18 } dirent_FILE_INFO_BY_HANDLE_CLASS;
 
static __ino_t __inode(const wchar_t* name) {
    __ino_t value = {0};
    BOOL result;
    dirent_FILE_ID_INFO fileid;
    BY_HANDLE_FILE_INFORMATION info;
    typedef BOOL(__stdcall * pfnGetFileInformationByHandleEx)(HANDLE hFile,
                                                              dirent_FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
                                                              LPVOID lpFileInformation, DWORD dwBufferSize);
 
    HANDLE hKernel32 = GetModuleHandleW(L"kernel32.dll");
    if (!hKernel32) return value;
 
    pfnGetFileInformationByHandleEx fnGetFileInformationByHandleEx =
        (pfnGetFileInformationByHandleEx)(void*)GetProcAddress(hKernel32, "GetFileInformationByHandleEx");
 
    if (!fnGetFileInformationByHandleEx) return value;
 
    HANDLE hFile = CreateFileW(name, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, 0);
    if (hFile == INVALID_HANDLE_VALUE) return value;
 
    result = fnGetFileInformationByHandleEx(hFile, dirent_FileIdInfo, &fileid, sizeof(fileid));
    if (result) {
        value.serial = fileid.VolumeSerialNumber;
        memcpy(value.fileid, fileid.FileId.Identifier, 16);
    } else {
        result = GetFileInformationByHandle(hFile, &info);
        if (result) {
            value.serial = info.dwVolumeSerialNumber;
            memcpy(value.fileid + 8, &info.nFileIndexHigh, 4);
            memcpy(value.fileid + 12, &info.nFileIndexLow, 4);
        }
    }
    CloseHandle(hFile);
    return value;
}
 
static DIR* __internal_opendir(wchar_t* wname, int size) {
    struct __dir* data = NULL;
    struct dirent* tmp_entries = NULL;
    static char default_char = '?';
    static wchar_t* suffix = L"\\*.*";
    static int extra_prefix = 4; /* use prefix "\\?\" to handle long file names */
    static int extra_suffix = 4; /* use suffix "\*.*" to find everything */
    WIN32_FIND_DATAW w32fd = {0};
    HANDLE hFindFile = INVALID_HANDLE_VALUE;
    static size_t grow_factor = 2;
    char* buffer = NULL;
 
    BOOL relative = PathIsRelativeW(wname + extra_prefix);
 
    memcpy(wname + size - 1, suffix, sizeof(wchar_t) * (size_t)extra_suffix);
    wname[size + extra_suffix - 1] = 0;
 
    if (relative) {
        wname += extra_prefix;
        size -= extra_prefix;
    }
    hFindFile = FindFirstFileW(wname, &w32fd);
    if (INVALID_HANDLE_VALUE == hFindFile) {
        __seterrno(ENOENT);
        return NULL;
    }
 
    data = (struct __dir*)malloc(sizeof(struct __dir));
    if (!data) goto out_of_memory;
    wname[size - 1] = 0;
    data->fd = (intptr_t)CreateFileW(wname, 0, 0, NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0);
    wname[size - 1] = L'\\';
    data->count = 16;
    data->index = 0;
    data->entries = (struct dirent*)malloc(sizeof(struct dirent) * (size_t)data->count);
    if (!data->entries) goto out_of_memory;
    buffer = malloc(MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
    if (!buffer) goto out_of_memory;
    do {
        WideCharToMultiByte(CP_UTF8, 0, w32fd.cFileName, -1, data->entries[data->index].d_name, NAME_MAX, &default_char,
                            NULL);
 
        memcpy(wname + size, w32fd.cFileName, sizeof(wchar_t) * NAME_MAX);
 
        if (((w32fd.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) == FILE_ATTRIBUTE_REPARSE_POINT) &&
            __islink(wname, buffer))
            data->entries[data->index].d_type = DT_LNK;
        else if ((w32fd.dwFileAttributes & FILE_ATTRIBUTE_DEVICE) == FILE_ATTRIBUTE_DEVICE)
            data->entries[data->index].d_type = DT_CHR;
        else if ((w32fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == FILE_ATTRIBUTE_DIRECTORY)
            data->entries[data->index].d_type = DT_DIR;
        else
            data->entries[data->index].d_type = DT_REG;
 
        data->entries[data->index].d_ino = __inode(wname);
        data->entries[data->index].d_reclen = sizeof(struct dirent);
        data->entries[data->index].d_namelen = (unsigned char)wcslen(w32fd.cFileName);
        data->entries[data->index].d_off = data->index + 1;  // POSIX fix: offset to next entry
 
        if (++data->index == data->count) {
            tmp_entries =
                (struct dirent*)realloc(data->entries, sizeof(struct dirent) * (size_t)data->count * grow_factor);
            if (!tmp_entries) goto out_of_memory;
            data->entries = tmp_entries;
            data->count *= grow_factor;
        }
    } while (FindNextFileW(hFindFile, &w32fd) != 0);
 
    free(buffer);
    FindClose(hFindFile);
 
    data->count = data->index;
    data->index = 0;
    return (DIR*)data;
out_of_memory:
    if (data) {
        if (INVALID_HANDLE_VALUE != (HANDLE)data->fd) CloseHandle((HANDLE)data->fd);
        free(data->entries);
    }
    free(buffer);
    free(data);
    if (INVALID_HANDLE_VALUE != hFindFile) FindClose(hFindFile);
    __seterrno(ENOMEM);
    return NULL;
}
 
static wchar_t* __get_buffer(void) {
    wchar_t* name = malloc(sizeof(wchar_t) * (NTFS_MAX_PATH + NAME_MAX + 8));
    if (name) memcpy(name, L"\\\\?\\", sizeof(wchar_t) * 4);
    return name;
}
 
DIR* opendir(const char* name) {
    DIR* dirp = NULL;
    wchar_t* wname = __get_buffer();
    int size = 0;
    if (!wname) {
        errno = ENOMEM;
        return NULL;
    }
    size = MultiByteToWideChar(CP_UTF8, 0, name, -1, wname + 4, NTFS_MAX_PATH);
    if (0 == size) {
        free(wname);
        return NULL;
    }
    dirp = __internal_opendir(wname, size + 4);
    free(wname);
    return dirp;
}
 
DIR* _wopendir(const wchar_t* name) {
    DIR* dirp = NULL;
    wchar_t* wname = __get_buffer();
    int size = 0;
    if (!wname) {
        errno = ENOMEM;
        return NULL;
    }
    size = wcslen(name);
    if (size > NTFS_MAX_PATH) {
        free(wname);
        return NULL;
    }
    memcpy(wname + 4, name, sizeof(wchar_t) * ((size_t)size + 1));
    dirp = __internal_opendir(wname, size + 5);
    free(wname);
    return dirp;
}
 
DIR* fdopendir(intptr_t fd) {
    DIR* dirp = NULL;
    wchar_t* wname = __get_buffer();
    typedef DWORD(__stdcall * pfnGetFinalPathNameByHandleW)(HANDLE hFile, LPWSTR lpszFilePath, DWORD cchFilePath,
                                                            DWORD dwFlags);
 
    HANDLE hKernel32 = GetModuleHandleW(L"kernel32.dll");
    if (!hKernel32) {
        errno = EINVAL;
        return NULL;
    }
 
    pfnGetFinalPathNameByHandleW fnGetFinalPathNameByHandleW =
        (pfnGetFinalPathNameByHandleW)(void*)GetProcAddress(hKernel32, "GetFinalPathNameByHandleW");
    if (!fnGetFinalPathNameByHandleW) {
        errno = EINVAL;
        return NULL;
    }
 
    size_t size = 0;
    if (!wname) {
        errno = ENOMEM;
        return NULL;
    }
    size = fnGetFinalPathNameByHandleW((HANDLE)fd, wname + 4, NTFS_MAX_PATH, FILE_NAME_NORMALIZED);
    if (0 == size) {
        free(wname);
        errno = ENOTDIR;
        return NULL;
    }
    dirp = __internal_opendir(wname, size + 5);
    free(wname);
    return dirp;
}
 
struct dirent* readdir(DIR* dirp) {
    struct __dir* data = (struct __dir*)dirp;
    if (!data) {
        errno = EBADF;
        return NULL;
    }
    if (data->index < data->count) {
        return &data->entries[data->index++];
    }
    return NULL;
}
 
int readdir_r(DIR* dirp, struct dirent* entry, struct dirent** result) {
    struct __dir* data = (struct __dir*)dirp;
    if (!data || !entry || !result) {
        return EINVAL;
    }
    if (data->index < data->count) {
        memcpy(entry, &data->entries[data->index++], sizeof(struct dirent));
        *result = entry;
    } else {
        *result = NULL;
    }
    return 0;
}
 
void seekdir(DIR* dirp, long int offset) {
    if (dirp) {
        struct __dir* data = (struct __dir*)dirp;
        if (offset >= 0 && offset <= data->count) {
            data->index = offset;
        }
    }
}
 
void rewinddir(DIR* dirp) { seekdir(dirp, 0); }
 
long int telldir(DIR* dirp) {
    if (!dirp) {
        errno = EBADF;
        return -1;
    }
    return ((struct __dir*)dirp)->index;
}
 
intptr_t dirfd(DIR* dirp) {
    if (!dirp) {
        errno = EINVAL;
        return -1;
    }
    return ((struct __dir*)dirp)->fd;
}
 
int scandir(const char* dirp, struct dirent*** namelist, int (*filter)(const struct dirent*),
            int (*compar)(const struct dirent**, const struct dirent**)) {
    struct dirent **entries = NULL, **tmp_entries = NULL;
    unsigned long int i = 0, index = 0, count = 16;
    DIR* d = opendir(dirp);
    struct __dir* data = (struct __dir*)d;
    if (!data) {
        closedir(d);
        __seterrno(ENOENT);
        return -1;
    }
    entries = (struct dirent**)malloc(sizeof(struct dirent*) * count);
    if (!entries) {
        closedir(d);
        __seterrno(ENOMEM);
        return -1;
    }
 
    for (i = 0; i < (size_t)data->count; ++i) {
        if (!filter || filter(&data->entries[i])) {
            entries[index] = (struct dirent*)malloc(sizeof(struct dirent));
            if (!entries[index]) {
                closedir(d);
                for (i = 0; i < index; ++i) free(entries[i]);
                free(entries);
                __seterrno(ENOMEM);
                return -1;
            }
            memcpy(entries[index], &data->entries[i], sizeof(struct dirent));
            if (++index == count) {
                tmp_entries = (struct dirent**)realloc(entries, sizeof(struct dirent*) * count * 2);
                if (!tmp_entries) {
                    closedir(d);
                    for (i = 0; i < index; ++i) free(entries[i]);
                    free(entries);
                    __seterrno(ENOMEM);
                    return -1;
                }
                entries = tmp_entries;
                count *= 2;
            }
        }
    }
    qsort(entries, index, sizeof(struct dirent*), (int (*)(const void*, const void*))compar);
    entries[index] = NULL;
    if (namelist) *namelist = entries;
    closedir(d);
    return (int)index;
}
 
int alphasort(const struct dirent** a, const struct dirent** b) {
    if (!a || !b || !*a || !*b) return 0;
    return strcoll((*a)->d_name, (*b)->d_name);
}
 
static int __strverscmp(const char* s1, const char* s2) {
    if (!s1 || !s2) return 0;
 
    while (*s1 && *s2) {
        if (isdigit((unsigned char)*s1) && isdigit((unsigned char)*s2)) {
            // Compare numeric parts
            unsigned long n1 = strtoul(s1, (char**)&s1, 10);
            unsigned long n2 = strtoul(s2, (char**)&s2, 10);
            if (n1 != n2) return (n1 < n2) ? -1 : 1;
        } else {
            if (*s1 != *s2) return ((unsigned char)*s1 < (unsigned char)*s2) ? -1 : 1;
            s1++;
            s2++;
        }
    }
    return *s1 ? 1 : (*s2 ? -1 : 0);
}
 
int versionsort(const struct dirent** a, const struct dirent** b) {
    if (!a || !b || !*a || !*b) return 0;
    return __strverscmp((*a)->d_name, (*b)->d_name);
}
 
#ifdef __cplusplus
}
#endif /* __cplusplus */
 
#endif /* _WIN32 */