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-rw-r--r--src/util/win32/path_w32.c642
1 files changed, 642 insertions, 0 deletions
diff --git a/src/util/win32/path_w32.c b/src/util/win32/path_w32.c
new file mode 100644
index 0000000..7a559e4
--- /dev/null
+++ b/src/util/win32/path_w32.c
@@ -0,0 +1,642 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "path_w32.h"
+
+#include "fs_path.h"
+#include "utf-conv.h"
+#include "posix.h"
+#include "reparse.h"
+#include "dir.h"
+
+#define PATH__NT_NAMESPACE L"\\\\?\\"
+#define PATH__NT_NAMESPACE_LEN 4
+
+#define PATH__ABSOLUTE_LEN 3
+
+#define path__is_nt_namespace(p) \
+ (((p)[0] == '\\' && (p)[1] == '\\' && (p)[2] == '?' && (p)[3] == '\\') || \
+ ((p)[0] == '/' && (p)[1] == '/' && (p)[2] == '?' && (p)[3] == '/'))
+
+#define path__is_unc(p) \
+ (((p)[0] == '\\' && (p)[1] == '\\') || ((p)[0] == '/' && (p)[1] == '/'))
+
+#define path__startswith_slash(p) \
+ ((p)[0] == '\\' || (p)[0] == '/')
+
+GIT_INLINE(int) path__cwd(wchar_t *path, int size)
+{
+ int len;
+
+ if ((len = GetCurrentDirectoryW(size, path)) == 0) {
+ errno = GetLastError() == ERROR_ACCESS_DENIED ? EACCES : ENOENT;
+ return -1;
+ } else if (len > size) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+
+ /* The Win32 APIs may return "\\?\" once you've used it first.
+ * But it may not. What a gloriously predictable API!
+ */
+ if (wcsncmp(path, PATH__NT_NAMESPACE, PATH__NT_NAMESPACE_LEN))
+ return len;
+
+ len -= PATH__NT_NAMESPACE_LEN;
+
+ memmove(path, path + PATH__NT_NAMESPACE_LEN, sizeof(wchar_t) * len);
+ return len;
+}
+
+static wchar_t *path__skip_server(wchar_t *path)
+{
+ wchar_t *c;
+
+ for (c = path; *c; c++) {
+ if (git_fs_path_is_dirsep(*c))
+ return c + 1;
+ }
+
+ return c;
+}
+
+static wchar_t *path__skip_prefix(wchar_t *path)
+{
+ if (path__is_nt_namespace(path)) {
+ path += PATH__NT_NAMESPACE_LEN;
+
+ if (wcsncmp(path, L"UNC\\", 4) == 0)
+ path = path__skip_server(path + 4);
+ else if (git_fs_path_is_absolute(path))
+ path += PATH__ABSOLUTE_LEN;
+ } else if (git_fs_path_is_absolute(path)) {
+ path += PATH__ABSOLUTE_LEN;
+ } else if (path__is_unc(path)) {
+ path = path__skip_server(path + 2);
+ }
+
+ return path;
+}
+
+int git_win32_path_canonicalize(git_win32_path path)
+{
+ wchar_t *base, *from, *to, *next;
+ size_t len;
+
+ base = to = path__skip_prefix(path);
+
+ /* Unposixify if the prefix */
+ for (from = path; from < to; from++) {
+ if (*from == L'/')
+ *from = L'\\';
+ }
+
+ while (*from) {
+ for (next = from; *next; ++next) {
+ if (*next == L'/') {
+ *next = L'\\';
+ break;
+ }
+
+ if (*next == L'\\')
+ break;
+ }
+
+ len = next - from;
+
+ if (len == 1 && from[0] == L'.')
+ /* do nothing with singleton dot */;
+
+ else if (len == 2 && from[0] == L'.' && from[1] == L'.') {
+ if (to == base) {
+ /* no more path segments to strip, eat the "../" */
+ if (*next == L'\\')
+ len++;
+
+ base = to;
+ } else {
+ /* back up a path segment */
+ while (to > base && to[-1] == L'\\') to--;
+ while (to > base && to[-1] != L'\\') to--;
+ }
+ } else {
+ if (*next == L'\\' && *from != L'\\')
+ len++;
+
+ if (to != from)
+ memmove(to, from, sizeof(wchar_t) * len);
+
+ to += len;
+ }
+
+ from += len;
+
+ while (*from == L'\\') from++;
+ }
+
+ /* Strip trailing backslashes */
+ while (to > base && to[-1] == L'\\') to--;
+
+ *to = L'\0';
+
+ if ((to - path) > INT_MAX) {
+ SetLastError(ERROR_FILENAME_EXCED_RANGE);
+ return -1;
+ }
+
+ return (int)(to - path);
+}
+
+static int git_win32_path_join(
+ git_win32_path dest,
+ const wchar_t *one,
+ size_t one_len,
+ const wchar_t *two,
+ size_t two_len)
+{
+ size_t backslash = 0;
+
+ if (one_len && two_len && one[one_len - 1] != L'\\')
+ backslash = 1;
+
+ if (one_len + two_len + backslash > MAX_PATH) {
+ git_error_set(GIT_ERROR_INVALID, "path too long");
+ return -1;
+ }
+
+ memmove(dest, one, one_len * sizeof(wchar_t));
+
+ if (backslash)
+ dest[one_len] = L'\\';
+
+ memcpy(dest + one_len + backslash, two, two_len * sizeof(wchar_t));
+ dest[one_len + backslash + two_len] = L'\0';
+
+ return 0;
+}
+
+struct win32_path_iter {
+ wchar_t *env;
+ const wchar_t *current_dir;
+};
+
+static int win32_path_iter_init(struct win32_path_iter *iter)
+{
+ DWORD len = GetEnvironmentVariableW(L"PATH", NULL, 0);
+
+ if (!len && GetLastError() == ERROR_ENVVAR_NOT_FOUND) {
+ iter->env = NULL;
+ iter->current_dir = NULL;
+ return 0;
+ } else if (!len) {
+ git_error_set(GIT_ERROR_OS, "could not load PATH");
+ return -1;
+ }
+
+ iter->env = git__malloc(len * sizeof(wchar_t));
+ GIT_ERROR_CHECK_ALLOC(iter->env);
+
+ len = GetEnvironmentVariableW(L"PATH", iter->env, len);
+
+ if (len == 0) {
+ git_error_set(GIT_ERROR_OS, "could not load PATH");
+ return -1;
+ }
+
+ iter->current_dir = iter->env;
+ return 0;
+}
+
+static int win32_path_iter_next(
+ const wchar_t **out,
+ size_t *out_len,
+ struct win32_path_iter *iter)
+{
+ const wchar_t *start;
+ wchar_t term;
+ size_t len = 0;
+
+ if (!iter->current_dir || !*iter->current_dir)
+ return GIT_ITEROVER;
+
+ term = (*iter->current_dir == L'"') ? *iter->current_dir++ : L';';
+ start = iter->current_dir;
+
+ while (*iter->current_dir && *iter->current_dir != term) {
+ iter->current_dir++;
+ len++;
+ }
+
+ *out = start;
+ *out_len = len;
+
+ if (term == L'"' && *iter->current_dir)
+ iter->current_dir++;
+
+ while (*iter->current_dir == L';')
+ iter->current_dir++;
+
+ return 0;
+}
+
+static void win32_path_iter_dispose(struct win32_path_iter *iter)
+{
+ if (!iter)
+ return;
+
+ git__free(iter->env);
+ iter->env = NULL;
+ iter->current_dir = NULL;
+}
+
+int git_win32_path_find_executable(git_win32_path fullpath, wchar_t *exe)
+{
+ struct win32_path_iter path_iter;
+ const wchar_t *dir;
+ size_t dir_len, exe_len = wcslen(exe);
+ bool found = false;
+
+ if (win32_path_iter_init(&path_iter) < 0)
+ return -1;
+
+ while (win32_path_iter_next(&dir, &dir_len, &path_iter) != GIT_ITEROVER) {
+ if (git_win32_path_join(fullpath, dir, dir_len, exe, exe_len) < 0)
+ continue;
+
+ if (_waccess(fullpath, 0) == 0) {
+ found = true;
+ break;
+ }
+ }
+
+ win32_path_iter_dispose(&path_iter);
+
+ if (found)
+ return 0;
+
+ fullpath[0] = L'\0';
+ return GIT_ENOTFOUND;
+}
+
+static int win32_path_cwd(wchar_t *out, size_t len)
+{
+ int cwd_len;
+
+ if (len > INT_MAX) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+
+ if ((cwd_len = path__cwd(out, (int)len)) < 0)
+ return -1;
+
+ /* UNC paths */
+ if (wcsncmp(L"\\\\", out, 2) == 0) {
+ /* Our buffer must be at least 5 characters larger than the
+ * current working directory: we swallow one of the leading
+ * '\'s, but we we add a 'UNC' specifier to the path, plus
+ * a trailing directory separator, plus a NUL.
+ */
+ if (cwd_len > GIT_WIN_PATH_MAX - 4) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+
+ memmove(out+2, out, sizeof(wchar_t) * cwd_len);
+ out[0] = L'U';
+ out[1] = L'N';
+ out[2] = L'C';
+
+ cwd_len += 2;
+ }
+
+ /* Our buffer must be at least 2 characters larger than the current
+ * working directory. (One character for the directory separator,
+ * one for the null.
+ */
+ else if (cwd_len > GIT_WIN_PATH_MAX - 2) {
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+
+ return cwd_len;
+}
+
+int git_win32_path_from_utf8(git_win32_path out, const char *src)
+{
+ wchar_t *dest = out;
+
+ /* All win32 paths are in NT-prefixed format, beginning with "\\?\". */
+ memcpy(dest, PATH__NT_NAMESPACE, sizeof(wchar_t) * PATH__NT_NAMESPACE_LEN);
+ dest += PATH__NT_NAMESPACE_LEN;
+
+ /* See if this is an absolute path (beginning with a drive letter) */
+ if (git_fs_path_is_absolute(src)) {
+ if (git_utf8_to_16(dest, GIT_WIN_PATH_MAX, src) < 0)
+ goto on_error;
+ }
+ /* File-prefixed NT-style paths beginning with \\?\ */
+ else if (path__is_nt_namespace(src)) {
+ /* Skip the NT prefix, the destination already contains it */
+ if (git_utf8_to_16(dest, GIT_WIN_PATH_MAX, src + PATH__NT_NAMESPACE_LEN) < 0)
+ goto on_error;
+ }
+ /* UNC paths */
+ else if (path__is_unc(src)) {
+ memcpy(dest, L"UNC\\", sizeof(wchar_t) * 4);
+ dest += 4;
+
+ /* Skip the leading "\\" */
+ if (git_utf8_to_16(dest, GIT_WIN_PATH_MAX - 2, src + 2) < 0)
+ goto on_error;
+ }
+ /* Absolute paths omitting the drive letter */
+ else if (path__startswith_slash(src)) {
+ if (path__cwd(dest, GIT_WIN_PATH_MAX) < 0)
+ goto on_error;
+
+ if (!git_fs_path_is_absolute(dest)) {
+ errno = ENOENT;
+ goto on_error;
+ }
+
+ /* Skip the drive letter specification ("C:") */
+ if (git_utf8_to_16(dest + 2, GIT_WIN_PATH_MAX - 2, src) < 0)
+ goto on_error;
+ }
+ /* Relative paths */
+ else {
+ int cwd_len;
+
+ if ((cwd_len = win32_path_cwd(dest, GIT_WIN_PATH_MAX)) < 0)
+ goto on_error;
+
+ dest[cwd_len++] = L'\\';
+
+ if (git_utf8_to_16(dest + cwd_len, GIT_WIN_PATH_MAX - cwd_len, src) < 0)
+ goto on_error;
+ }
+
+ return git_win32_path_canonicalize(out);
+
+on_error:
+ /* set windows error code so we can use its error message */
+ if (errno == ENAMETOOLONG)
+ SetLastError(ERROR_FILENAME_EXCED_RANGE);
+
+ return -1;
+}
+
+int git_win32_path_relative_from_utf8(git_win32_path out, const char *src)
+{
+ wchar_t *dest = out, *p;
+ int len;
+
+ /* Handle absolute paths */
+ if (git_fs_path_is_absolute(src) ||
+ path__is_nt_namespace(src) ||
+ path__is_unc(src) ||
+ path__startswith_slash(src)) {
+ return git_win32_path_from_utf8(out, src);
+ }
+
+ if ((len = git_utf8_to_16(dest, GIT_WIN_PATH_MAX, src)) < 0)
+ return -1;
+
+ for (p = dest; p < (dest + len); p++) {
+ if (*p == L'/')
+ *p = L'\\';
+ }
+
+ return len;
+}
+
+int git_win32_path_to_utf8(git_win32_utf8_path dest, const wchar_t *src)
+{
+ char *out = dest;
+ int len;
+
+ /* Strip NT namespacing "\\?\" */
+ if (path__is_nt_namespace(src)) {
+ src += 4;
+
+ /* "\\?\UNC\server\share" -> "\\server\share" */
+ if (wcsncmp(src, L"UNC\\", 4) == 0) {
+ src += 4;
+
+ memcpy(dest, "\\\\", 2);
+ out = dest + 2;
+ }
+ }
+
+ if ((len = git_utf8_from_16(out, GIT_WIN_PATH_UTF8, src)) < 0)
+ return len;
+
+ git_fs_path_mkposix(dest);
+
+ return len;
+}
+
+char *git_win32_path_8dot3_name(const char *path)
+{
+ git_win32_path longpath, shortpath;
+ wchar_t *start;
+ char *shortname;
+ int len, namelen = 1;
+
+ if (git_win32_path_from_utf8(longpath, path) < 0)
+ return NULL;
+
+ len = GetShortPathNameW(longpath, shortpath, GIT_WIN_PATH_UTF16);
+
+ while (len && shortpath[len-1] == L'\\')
+ shortpath[--len] = L'\0';
+
+ if (len == 0 || len >= GIT_WIN_PATH_UTF16)
+ return NULL;
+
+ for (start = shortpath + (len - 1);
+ start > shortpath && *(start-1) != '/' && *(start-1) != '\\';
+ start--)
+ namelen++;
+
+ /* We may not have actually been given a short name. But if we have,
+ * it will be in the ASCII byte range, so we don't need to worry about
+ * multi-byte sequences and can allocate naively.
+ */
+ if (namelen > 12 || (shortname = git__malloc(namelen + 1)) == NULL)
+ return NULL;
+
+ if ((len = git_utf8_from_16(shortname, namelen + 1, start)) < 0)
+ return NULL;
+
+ return shortname;
+}
+
+static bool path_is_volume(wchar_t *target, size_t target_len)
+{
+ return (target_len && wcsncmp(target, L"\\??\\Volume{", 11) == 0);
+}
+
+/* On success, returns the length, in characters, of the path stored in dest.
+ * On failure, returns a negative value. */
+int git_win32_path_readlink_w(git_win32_path dest, const git_win32_path path)
+{
+ BYTE buf[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+ GIT_REPARSE_DATA_BUFFER *reparse_buf = (GIT_REPARSE_DATA_BUFFER *)buf;
+ HANDLE handle = NULL;
+ DWORD ioctl_ret;
+ wchar_t *target;
+ size_t target_len;
+
+ int error = -1;
+
+ handle = CreateFileW(path, GENERIC_READ,
+ FILE_SHARE_READ | FILE_SHARE_DELETE, NULL, OPEN_EXISTING,
+ FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, NULL);
+
+ if (handle == INVALID_HANDLE_VALUE) {
+ errno = ENOENT;
+ return -1;
+ }
+
+ if (!DeviceIoControl(handle, FSCTL_GET_REPARSE_POINT, NULL, 0,
+ reparse_buf, sizeof(buf), &ioctl_ret, NULL)) {
+ errno = EINVAL;
+ goto on_error;
+ }
+
+ switch (reparse_buf->ReparseTag) {
+ case IO_REPARSE_TAG_SYMLINK:
+ target = reparse_buf->ReparseBuffer.SymbolicLink.PathBuffer +
+ (reparse_buf->ReparseBuffer.SymbolicLink.SubstituteNameOffset / sizeof(WCHAR));
+ target_len = reparse_buf->ReparseBuffer.SymbolicLink.SubstituteNameLength / sizeof(WCHAR);
+ break;
+ case IO_REPARSE_TAG_MOUNT_POINT:
+ target = reparse_buf->ReparseBuffer.MountPoint.PathBuffer +
+ (reparse_buf->ReparseBuffer.MountPoint.SubstituteNameOffset / sizeof(WCHAR));
+ target_len = reparse_buf->ReparseBuffer.MountPoint.SubstituteNameLength / sizeof(WCHAR);
+ break;
+ default:
+ errno = EINVAL;
+ goto on_error;
+ }
+
+ if (path_is_volume(target, target_len)) {
+ /* This path is a reparse point that represents another volume mounted
+ * at this location, it is not a symbolic link our input was canonical.
+ */
+ errno = EINVAL;
+ error = -1;
+ } else if (target_len) {
+ /* The path may need to have a namespace prefix removed. */
+ target_len = git_win32_path_remove_namespace(target, target_len);
+
+ /* Need one additional character in the target buffer
+ * for the terminating NULL. */
+ if (GIT_WIN_PATH_UTF16 > target_len) {
+ wcscpy(dest, target);
+ error = (int)target_len;
+ }
+ }
+
+on_error:
+ CloseHandle(handle);
+ return error;
+}
+
+/**
+ * Removes any trailing backslashes from a path, except in the case of a drive
+ * letter path (C:\, D:\, etc.). This function cannot fail.
+ *
+ * @param path The path which should be trimmed.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32_path_trim_end(wchar_t *str, size_t len)
+{
+ while (1) {
+ if (!len || str[len - 1] != L'\\')
+ break;
+
+ /*
+ * Don't trim backslashes from drive letter paths, which
+ * are 3 characters long and of the form C:\, D:\, etc.
+ */
+ if (len == 3 && git_win32__isalpha(str[0]) && str[1] == ':')
+ break;
+
+ len--;
+ }
+
+ str[len] = L'\0';
+
+ return len;
+}
+
+/**
+ * Removes any of the following namespace prefixes from a path,
+ * if found: "\??\", "\\?\", "\\?\UNC\". This function cannot fail.
+ *
+ * @param path The path which should be converted.
+ * @return The length of the modified string (<= the input length)
+ */
+size_t git_win32_path_remove_namespace(wchar_t *str, size_t len)
+{
+ static const wchar_t dosdevices_namespace[] = L"\\\?\?\\";
+ static const wchar_t nt_namespace[] = L"\\\\?\\";
+ static const wchar_t unc_namespace_remainder[] = L"UNC\\";
+ static const wchar_t unc_prefix[] = L"\\\\";
+
+ const wchar_t *prefix = NULL, *remainder = NULL;
+ size_t prefix_len = 0, remainder_len = 0;
+
+ /* "\??\" -- DOS Devices prefix */
+ if (len >= CONST_STRLEN(dosdevices_namespace) &&
+ !wcsncmp(str, dosdevices_namespace, CONST_STRLEN(dosdevices_namespace))) {
+ remainder = str + CONST_STRLEN(dosdevices_namespace);
+ remainder_len = len - CONST_STRLEN(dosdevices_namespace);
+ }
+ /* "\\?\" -- NT namespace prefix */
+ else if (len >= CONST_STRLEN(nt_namespace) &&
+ !wcsncmp(str, nt_namespace, CONST_STRLEN(nt_namespace))) {
+ remainder = str + CONST_STRLEN(nt_namespace);
+ remainder_len = len - CONST_STRLEN(nt_namespace);
+ }
+
+ /* "\??\UNC\", "\\?\UNC\" -- UNC prefix */
+ if (remainder_len >= CONST_STRLEN(unc_namespace_remainder) &&
+ !wcsncmp(remainder, unc_namespace_remainder, CONST_STRLEN(unc_namespace_remainder))) {
+
+ /*
+ * The proper Win32 path for a UNC share has "\\" at beginning of it
+ * and looks like "\\server\share\<folderStructure>". So remove the
+ * UNC namespace and add a prefix of "\\" in its place.
+ */
+ remainder += CONST_STRLEN(unc_namespace_remainder);
+ remainder_len -= CONST_STRLEN(unc_namespace_remainder);
+
+ prefix = unc_prefix;
+ prefix_len = CONST_STRLEN(unc_prefix);
+ }
+
+ /*
+ * Sanity check that the new string isn't longer than the old one.
+ * (This could only happen due to programmer error introducing a
+ * prefix longer than the namespace it replaces.)
+ */
+ if (remainder && len >= remainder_len + prefix_len) {
+ if (prefix)
+ memmove(str, prefix, prefix_len * sizeof(wchar_t));
+
+ memmove(str + prefix_len, remainder, remainder_len * sizeof(wchar_t));
+
+ len = remainder_len + prefix_len;
+ str[len] = L'\0';
+ }
+
+ return git_win32_path_trim_end(str, len);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 22:10:54 +0000