win32.c: Misc. fixes
authorEric Biggers <ebiggers3@gmail.com>
Fri, 22 Mar 2013 04:25:12 +0000 (23:25 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Fri, 22 Mar 2013 04:25:12 +0000 (23:25 -0500)
- Fix comments
- Document parameters to DeviceIOControl in win32_capture_reparse_point()
- win32_capture_stream(): Avoid ambiguity between drive letters and paths to
  alternate data streams
- win32_extract_stream(): Don't treat paths beginning with drive letter as
  relative

src/win32.c

index f094656..ba3dc58 100644 (file)
@@ -236,9 +236,10 @@ win32_recurse_directory(struct wim_dentry *root,
        ret = 0;
        do {
                /* Skip . and .. entries */
-               if (!(dat.cFileName[0] == L'.' &&
-                     (dat.cFileName[1] == L'\0' ||
-                      (dat.cFileName[1] == L'.' && dat.cFileName[2] == L'\0'))))
+               if (!(dat.cFileName[0] == cpu_to_le16(L'.') &&
+                     (dat.cFileName[1] == cpu_to_le16(L'\0') ||
+                      (dat.cFileName[1] == cpu_to_le16(L'.') &&
+                       dat.cFileName[2] == cpu_to_le16(L'\0')))))
                {
                        struct wim_dentry *child;
 
@@ -286,8 +287,7 @@ out_find_close:
  *                 for the reparse point unless an entry already exists for
  *                 the exact same data stream.
  *
- * @path:  External path to the parse point (UTF-8).  Used for error messages
- *         only.
+ * @path:  External path to the reparse point.  Used for error messages only.
  *
  * Returns 0 on success; nonzero on failure. */
 static int
@@ -302,8 +302,14 @@ win32_capture_reparse_point(HANDLE hFile,
        DWORD bytesReturned;
 
        if (!DeviceIoControl(hFile, FSCTL_GET_REPARSE_POINT,
-                            NULL, 0, reparse_point_buf,
-                            sizeof(reparse_point_buf), &bytesReturned, NULL))
+                            NULL, /* "Not used with this operation; set to NULL" */
+                            0, /* "Not used with this operation; set to 0" */
+                            reparse_point_buf, /* "A pointer to a buffer that
+                                                  receives the reparse point data */
+                            sizeof(reparse_point_buf), /* "The size of the output
+                                                          buffer, in bytes */
+                            &bytesReturned,
+                            NULL))
        {
                DWORD err = GetLastError();
                ERROR("Win32 API: Failed to get reparse data of \"%s\"", path);
@@ -316,7 +322,7 @@ win32_capture_reparse_point(HANDLE hFile,
        }
        inode->i_reparse_tag = le32_to_cpu(*(u32*)reparse_point_buf);
        return inode_add_ads_with_data(inode, "",
-                                      (const u8*)reparse_point_buf + 8,
+                                      reparse_point_buf + 8,
                                       bytesReturned - 8, lookup_table);
 }
 
@@ -390,18 +396,22 @@ win32_capture_stream(const wchar_t *path_utf16,
        u8 hash[SHA1_HASH_SIZE];
        struct wim_lookup_table_entry *lte;
        int ret;
-       wchar_t *p, *colon;
+       wchar_t *stream_name, *colon;
+       size_t stream_name_nchars;
        bool is_named_stream;
        wchar_t *spath;
        size_t spath_nchars;
        DWORD err;
+       size_t spath_buf_nbytes;
+       const wchar_t *relpath_prefix;
+       const wchar_t *colonchar;
 
        /* The stream name should be returned as :NAME:TYPE */
-       p = dat->cStreamName;
-       if (*p != L':')
+       stream_name = dat->cStreamName;
+       if (*stream_name != L':')
                goto out_invalid_stream_name;
-       p += 1;
-       colon = wcschr(p, L':');
+       stream_name += 1;
+       colon = wcschr(stream_name, L':');
        if (colon == NULL)
                goto out_invalid_stream_name;
 
@@ -411,47 +421,56 @@ win32_capture_stream(const wchar_t *path_utf16,
                goto out;
        }
 
-       is_named_stream = (p != colon);
+       *colon = '\0';
+
+       stream_name_nchars = colon - stream_name;
+       is_named_stream = (stream_name_nchars != 0);
+
        if (is_named_stream) {
                /* Allocate an ADS entry for the named stream. */
-               mbchar *mbs_stream_name;
-               size_t mbs_stream_name_nbytes;
-               ret = utf16le_to_mbs(p,
-                                    (colon - p) * sizeof(wchar_t),
-                                    &mbs_stream_name,
-                                    &mbs_stream_name_nbytes);
-               if (ret)
-                       goto out;
-               ads_entry = inode_add_ads(inode, mbs_stream_name);
-               FREE(mbs_stream_name);
+               ads_entry = inode_add_ads_utf16le(inode, stream_name,
+                                                 stream_name_nchars * 2);
                if (!ads_entry) {
                        ret = WIMLIB_ERR_NOMEM;
                        goto out;
                }
        }
 
-       /* Create a UTF-16 string @spath that gives the filename, then a colon,
-        * then the stream name.  Or, if it's an unnamed stream, just the
+       /* Create a UTF-16LE string @spath that gives the filename, then a
+        * colon, then the stream name.  Or, if it's an unnamed stream, just the
         * filename.  It is MALLOC()'ed so that it can be saved in the
-        * wim_lookup_table_entry if needed. */
-       *colon = '\0';
+        * wim_lookup_table_entry if needed.
+        *
+        * As yet another special case, relative paths need to be changed to
+        * begin with an explicit "./" so that, for example, a file t:ads, where
+        * :ads is the part we added, is not interpreted as a file on the t:
+        * drive. */
        spath_nchars = path_utf16_nchars;
-       if (is_named_stream)
-               spath_nchars += colon - p + 1;
-
-       spath = MALLOC((spath_nchars + 1) * sizeof(wchar_t));
-       memcpy(spath, path_utf16, path_utf16_nchars * sizeof(wchar_t));
+       relpath_prefix = L"";
+       colonchar = L"";
        if (is_named_stream) {
-               spath[path_utf16_nchars] = L':';
-               memcpy(&spath[path_utf16_nchars + 1], p, (colon - p) * sizeof(wchar_t));
+               spath_nchars += 1 + stream_name_nchars;
+               colonchar = L":";
+               if (path_utf16_nchars == 1 &&
+                   path_utf16[0] != cpu_to_le16('/') &&
+                   path_utf16[0] != cpu_to_le16('\\'))
+               {
+                       spath_nchars += 2;
+                       relpath_prefix = L"./";
+               }
        }
-       spath[spath_nchars] = L'\0';
+
+       spath_buf_nbytes = (spath_nchars + 1) * sizeof(wchar_t);
+       spath = MALLOC(spath_buf_nbytes);
+
+       swprintf(spath, spath_buf_nbytes, L"%ls%ls%ls%ls",
+                relpath_prefix, path_utf16, colonchar, stream_name);
 
        ret = win32_sha1sum(spath, hash);
        if (ret) {
                err = GetLastError();
                ERROR("Win32 API: Failed to read \"%ls\" to calculate SHA1sum",
-                     path_utf16);
+                     spath);
                win32_error(err);
                goto out_free_spath;
        }
@@ -833,7 +852,7 @@ win32_extract_stream(const struct wim_inode *inode,
 
        if (stream_name_utf16) {
                /* Named stream.  Create a buffer that contains the UTF-16LE
-                * string [./]@path:@stream_name_utf16.  This is needed to
+                * string [.\]@path:@stream_name_utf16.  This is needed to
                 * create and open the stream using CreateFileW().  I'm not
                 * aware of any other APIs to do this.  Note: the '$DATA' suffix
                 * seems to be unneeded.  Additional note: a "./" prefix needs
@@ -847,7 +866,11 @@ win32_extract_stream(const struct wim_inode *inode,
                path_nchars = wcslen(path);
                stream_name_nchars = wcslen(stream_name_utf16);
                stream_path_nchars = path_nchars + 1 + stream_name_nchars;
-               if (path[0] != L'/' && path[0] != L'\\') {
+               if (path[0] != cpu_to_le16(L'\0') &&
+                   path[0] != cpu_to_le16(L'/') &&
+                   path[0] != cpu_to_le16(L'\\') &&
+                   path[1] != cpu_to_le16(L':'))
+               {
                        prefix = L"./";
                        stream_path_nchars += 2;
                } else {