From 8f002964fbc9b49030630c5c0045b1254e3740da Mon Sep 17 00:00:00 2001 From: Luke Pulverenti Date: Tue, 1 Oct 2013 15:18:52 -0400 Subject: [PATCH] parse shortcuts without native code --- MediaBrowser.Controller/IO/FileSystem.cs | 144 +++++++++++++++++++++-- 1 file changed, 132 insertions(+), 12 deletions(-) diff --git a/MediaBrowser.Controller/IO/FileSystem.cs b/MediaBrowser.Controller/IO/FileSystem.cs index 30fdb8d39..0879ea8a4 100644 --- a/MediaBrowser.Controller/IO/FileSystem.cs +++ b/MediaBrowser.Controller/IO/FileSystem.cs @@ -108,7 +108,7 @@ namespace MediaBrowser.Controller.IO } var builder = new StringBuilder(filename); - + foreach (var c in InvalidFileNameChars) { builder = builder.Replace(c, SpaceChar); @@ -129,15 +129,17 @@ namespace MediaBrowser.Controller.IO { throw new ArgumentNullException("filename"); } - - var link = new ShellLink(); - ((IPersistFile)link).Load(filename, NativeMethods.STGM_READ); - // TODO: if I can get hold of the hwnd call resolve first. This handles moved and renamed files. - // ((IShellLinkW)link).Resolve(hwnd, 0) - var sb = new StringBuilder(NativeMethods.MAX_PATH); - WIN32_FIND_DATA data; - ((IShellLinkW)link).GetPath(sb, sb.Capacity, out data, 0); - return sb.ToString(); + + return new WindowsShortcut(filename).ResolvedPath; + + //var link = new ShellLink(); + //((IPersistFile)link).Load(filename, NativeMethods.STGM_READ); + //// TODO: if I can get hold of the hwnd call resolve first. This handles moved and renamed files. + //// ((IShellLinkW)link).Resolve(hwnd, 0) + //var sb = new StringBuilder(NativeMethods.MAX_PATH); + //WIN32_FIND_DATA data; + //((IShellLinkW)link).GetPath(sb, sb.Capacity, out data, 0); + //return sb.ToString(); } /// @@ -157,7 +159,7 @@ namespace MediaBrowser.Controller.IO { throw new ArgumentNullException("target"); } - + var link = new ShellLink(); ((IShellLinkW)link).SetPath(target); @@ -177,7 +179,7 @@ namespace MediaBrowser.Controller.IO { throw new ArgumentNullException("filename"); } - + return string.Equals(Path.GetExtension(filename), ".lnk", StringComparison.OrdinalIgnoreCase); } @@ -244,4 +246,122 @@ namespace MediaBrowser.Controller.IO return values; } } + + public class WindowsShortcut + { + public bool IsDirectory { get; private set; } + public bool IsLocal { get; private set; } + public string ResolvedPath { get; private set; } + + public WindowsShortcut(string file) + { + ParseLink(File.ReadAllBytes(file)); + } + + private static bool isMagicPresent(byte[] link) + { + + const int magic = 0x0000004C; + const int magic_offset = 0x00; + + return link.Length >= 32 && bytesToDword(link, magic_offset) == magic; + } + + /** + * Gobbles up link data by parsing it and storing info in member fields + * @param link all the bytes from the .lnk file + */ + private void ParseLink(byte[] link) + { + if (!isMagicPresent(link)) + throw new IOException("Invalid shortcut; magic is missing", 0); + + // get the flags byte + byte flags = link[0x14]; + + // get the file attributes byte + const int file_atts_offset = 0x18; + byte file_atts = link[file_atts_offset]; + byte is_dir_mask = (byte)0x10; + if ((file_atts & is_dir_mask) > 0) + { + IsDirectory = true; + } + else + { + IsDirectory = false; + } + + // if the shell settings are present, skip them + const int shell_offset = 0x4c; + const byte has_shell_mask = (byte)0x01; + int shell_len = 0; + if ((flags & has_shell_mask) > 0) + { + // the plus 2 accounts for the length marker itself + shell_len = bytesToWord(link, shell_offset) + 2; + } + + // get to the file settings + int file_start = 0x4c + shell_len; + + const int file_location_info_flag_offset_offset = 0x08; + int file_location_info_flag = link[file_start + file_location_info_flag_offset_offset]; + IsLocal = (file_location_info_flag & 2) == 0; + // get the local volume and local system values + //final int localVolumeTable_offset_offset = 0x0C; + const int basename_offset_offset = 0x10; + const int networkVolumeTable_offset_offset = 0x14; + const int finalname_offset_offset = 0x18; + int finalname_offset = link[file_start + finalname_offset_offset] + file_start; + String finalname = getNullDelimitedString(link, finalname_offset); + if (IsLocal) + { + int basename_offset = link[file_start + basename_offset_offset] + file_start; + String basename = getNullDelimitedString(link, basename_offset); + ResolvedPath = basename + finalname; + } + else + { + int networkVolumeTable_offset = link[file_start + networkVolumeTable_offset_offset] + file_start; + int shareName_offset_offset = 0x08; + int shareName_offset = link[networkVolumeTable_offset + shareName_offset_offset] + + networkVolumeTable_offset; + String shareName = getNullDelimitedString(link, shareName_offset); + ResolvedPath = shareName + "\\" + finalname; + } + } + + private static string getNullDelimitedString(byte[] bytes, int off) + { + int len = 0; + + // count bytes until the null character (0) + while (true) + { + if (bytes[off + len] == 0) + { + break; + } + len++; + } + + return Encoding.UTF8.GetString(bytes, off, len); + } + + /* + * convert two bytes into a short note, this is little endian because it's + * for an Intel only OS. + */ + private static int bytesToWord(byte[] bytes, int off) + { + return ((bytes[off + 1] & 0xff) << 8) | (bytes[off] & 0xff); + } + + private static int bytesToDword(byte[] bytes, int off) + { + return (bytesToWord(bytes, off + 2) << 16) | bytesToWord(bytes, off); + } + + } }