Add File & Directory skipping (#61)

* Add File & Directory skipping

include/sharedparameters.h

@@ -57,6 +57,14 @@ class DLLEXPORT SharedParameters
   void clearExecutableBlacklist();
   bool executableBlacklisted(const std::string& app, const std::string& cmd) const;
 
+  void addSkipFileSuffix(const std::string& fileSuffix);
+  void clearSkipFileSuffixes();
+  std::vector<std::string> skipFileSuffixes() const;
+
+  void addSkipDirectory(const std::string& directory);
+  void clearSkipDirectories();
+  std::vector<std::string> skipDirectories() const;
+
   void addForcedLibrary(const std::string& process, const std::string& path);
   std::vector<std::string> forcedLibraries(const std::string& processName);
   void clearForcedLibraries();
@@ -77,6 +85,12 @@ class DLLEXPORT SharedParameters
   using ProcessList = boost::container::flat_set<
     DWORD, std::less<DWORD>, DWORDAllocatorT>;
 
+  using FileSuffixSkipList = boost::container::flat_set<
+      shared::StringT, std::less<shared::StringT>, StringAllocatorT>;
+
+  using DirectorySkipList = boost::container::flat_set<
+      shared::StringT, std::less<shared::StringT>, StringAllocatorT>;
+
   using ForcedLibraries = boost::container::slist<
     ForcedLibrary, ForcedLibraryAllocatorT>;
 
@@ -93,6 +107,8 @@ class DLLEXPORT SharedParameters
   uint32_t m_userCount;
   ProcessBlacklist m_processBlacklist;
   ProcessList m_processList;
+  FileSuffixSkipList m_fileSuffixSkipList;
+  DirectorySkipList m_directorySkipList;
   ForcedLibraries m_forcedLibraries;
 };
 

include/usvfs.h

@@ -49,7 +49,10 @@ static const unsigned int LINKFLAG_CREATETARGET   = 0x00000004; // if set, file
                                                                 // If there different create-target have been set for an element and one of its
                                                                 // ancestors, the inner-most create-target is used
 static const unsigned int LINKFLAG_RECURSIVE      = 0x00000008; // if set, directories are linked recursively
-
+static const unsigned int LINKFLAG_FAILIFSKIPPED  = 0x00000010; // if set, linking fails if the file or directory is skipped
+                                                                // files or directories are skipped depending on whats been added to 
+                                                                // the skip file suffixes or skip directories list in
+                                                                // the sharedparameters class, those lists are checked during virtual linking
 
 extern "C" {
 
@@ -154,6 +157,34 @@ DLLEXPORT VOID WINAPI BlacklistExecutable(LPWSTR executableName);
  */
 DLLEXPORT VOID WINAPI ClearExecutableBlacklist();
 
+/**
+ * adds a file suffix to a list to skip during file linking
+ * .txt and some_file.txt are both valid file suffixes,
+ * not to be confused with file extensions
+ * @param fileSuffix  a valid file suffix
+ */
+DLLEXPORT VOID WINAPI usvfsAddSkipFileSuffix(LPWSTR fileSuffix);
+
+/**
+ * clears the file suffix skip-list
+ */
+DLLEXPORT VOID WINAPI usvfsClearSkipFileSuffixes();
+
+/**
+ * adds a directory name that will be skipped during directory linking.
+ * Not a path. Any directory matching the name will be skipped,
+ * regardless of it's path, for example if .git is added,
+ * any sub-path or root-path containing a .git directory
+ * will have the .git directory skipped during directory linking
+ * @param directory  name of the directory
+ */
+DLLEXPORT VOID WINAPI usvfsAddSkipDirectory(LPWSTR directory);
+
+/**
+ * clears the directory skip-list
+ */
+DLLEXPORT VOID WINAPI usvfsClearSkipDirectories();
+
 /**
  * adds a library to be force loaded when the given process is injected
  * @param

src/usvfs_dll/hookcontext.cpp

@@ -216,6 +216,52 @@ BOOL HookContext::executableBlacklisted(LPCWSTR wapp, LPCWSTR wcmd) const
   return m_Parameters->executableBlacklisted(app, cmd);
 }
 
+void usvfs::HookContext::addSkipFileSuffix(const std::wstring& fileSuffix) 
+{
+  const auto fsuffix = shared::string_cast<std::string>(fileSuffix, shared::CodePage::UTF8);
+
+  if (fsuffix.empty()) {
+    return;
+  }
+
+  spdlog::get("usvfs")->debug("added skip file suffix '{}'", fsuffix);
+  m_Parameters->addSkipFileSuffix(fsuffix);
+}
+
+void usvfs::HookContext::clearSkipFileSuffixes() 
+{
+  spdlog::get("usvfs")->debug("clearing skip file suffixes");
+  m_Parameters->clearSkipFileSuffixes();
+}
+
+std::vector<std::string> usvfs::HookContext::skipFileSuffixes() const
+{
+  return m_Parameters->skipFileSuffixes();
+}
+
+void usvfs::HookContext::addSkipDirectory(const std::wstring& directory) 
+{
+  const auto dir = shared::string_cast<std::string>(directory, shared::CodePage::UTF8);
+
+  if (dir.empty()) {
+    return;
+  }
+
+  spdlog::get("usvfs")->debug("added skip directory '{}'", dir);
+  m_Parameters->addSkipDirectory(dir);
+}
+
+void usvfs::HookContext::clearSkipDirectories() 
+{
+  spdlog::get("usvfs")->debug("clearing skip directories");
+  m_Parameters->clearSkipDirectories();
+}
+
+std::vector<std::string> usvfs::HookContext::skipDirectories() const
+{
+  return m_Parameters->skipDirectories();
+}
+
 void HookContext::forceLoadLibrary(
   const std::wstring& wprocess, const std::wstring& wpath)
 {

src/usvfs_dll/hookcontext.h

@@ -144,6 +144,14 @@ class HookContext
   void clearExecutableBlacklist();
   BOOL HookContext::executableBlacklisted(LPCWSTR lpApplicationName, LPCWSTR lpCommandLine) const;
 
+  void addSkipFileSuffix(const std::wstring& fileSuffix);
+  void clearSkipFileSuffixes();
+  std::vector<std::string> skipFileSuffixes() const;
+
+  void addSkipDirectory(const std::wstring& directory);
+  void clearSkipDirectories();
+  std::vector<std::string> skipDirectories () const;
+
   void forceLoadLibrary(const std::wstring &processName, const std::wstring &libraryPath);
   void clearLibraryForceLoads();
   std::vector<std::wstring> librariesToForceLoad(const std::wstring &processName);

src/usvfs_dll/sharedparameters.cpp

@@ -37,6 +37,8 @@ SharedParameters::SharedParameters(const usvfsParameters& reference,
   , m_userCount(1)
   , m_processBlacklist(allocator)
   , m_processList(allocator)
+  , m_fileSuffixSkipList(allocator)
+  , m_directorySkipList(allocator)
   , m_forcedLibraries(allocator)
 {
 }
@@ -198,6 +200,46 @@ bool SharedParameters::executableBlacklisted(
   return false;
 }
 
+void SharedParameters::addSkipFileSuffix(const std::string& fileSuffix)
+{
+  bi::scoped_lock lock(m_mutex);
+
+  m_fileSuffixSkipList.insert(shared::StringT(fileSuffix.begin(), fileSuffix.end(),
+                                              m_fileSuffixSkipList.get_allocator()));
+}
+
+void SharedParameters::clearSkipFileSuffixes()
+{
+  bi::scoped_lock lock(m_mutex);
+  m_fileSuffixSkipList.clear();
+}
+
+std::vector<std::string> SharedParameters::skipFileSuffixes() const
+{
+  bi::scoped_lock lock(m_mutex);
+  return { m_fileSuffixSkipList.begin(), m_fileSuffixSkipList.end() };
+}
+
+void SharedParameters::addSkipDirectory(const std::string& directory) 
+{
+  bi::scoped_lock lock(m_mutex);
+
+  m_directorySkipList.insert(shared::StringT(directory.begin(), directory.end(),
+                                              m_directorySkipList.get_allocator()));
+}
+
+void SharedParameters::clearSkipDirectories() 
+{
+  bi::scoped_lock lock(m_mutex);
+  m_directorySkipList.clear();
+}
+
+std::vector<std::string> SharedParameters::skipDirectories() const
+{
+  bi::scoped_lock lock(m_mutex);
+  return { m_directorySkipList.begin(), m_directorySkipList.end() };
+}
+
 void SharedParameters::addForcedLibrary(
   const std::string& processName, const std::string& libraryPath)
 {

src/usvfs_dll/usvfs.cpp

@@ -672,6 +672,33 @@ bool assertPathExists(usvfs::RedirectionTreeContainer &table, LPCWSTR path)
   return true;
 }
 
+static bool fileNameInSkipSuffixes(const std::string& fileNameUtf8,
+                                   const std::vector<std::string>& skipFileSuffixes)
+{
+  for (const auto& skipFileSuffix : skipFileSuffixes) {
+    if (boost::algorithm::iends_with(fileNameUtf8, skipFileSuffix)) {
+      spdlog::get("usvfs")->debug(
+          "file '{}' should be skipped, matches file suffix '{}'", fileNameUtf8,
+          skipFileSuffix);
+      return true;
+    }
+  }
+  return false;
+}
+
+static bool fileNameInSkipDirectories(const std::string& directoryNameUtf8,
+                                      const std::vector<std::string>& skipDirectories)
+{
+  for (const auto& skipDir : skipDirectories) {
+    if (boost::algorithm::equals(directoryNameUtf8, skipDir)) {
+      spdlog::get("usvfs")->debug("directory '{}' should be skipped",
+                                  directoryNameUtf8);
+      return true;
+    }
+  }
+  return false;
+}
+
 BOOL WINAPI VirtualLinkFile(LPCWSTR source, LPCWSTR destination,
                             unsigned int flags)
 {
@@ -683,8 +710,16 @@ BOOL WINAPI VirtualLinkFile(LPCWSTR source, LPCWSTR destination,
       return FALSE;
     }
 
-    std::string sourceU8
-        = ush::string_cast<std::string>(source, ush::CodePage::UTF8);
+    const auto skipFileSuffixes = context->skipFileSuffixes();
+
+    std::string sourceU8 = ush::string_cast<std::string>(source, ush::CodePage::UTF8);
+
+    // Check if the file should be skipped
+    if (fileNameInSkipSuffixes(sourceU8, skipFileSuffixes)) {
+      // return false when we want to fail when the file is skipped
+      return (flags & LINKFLAG_FAILIFSKIPPED) ? FALSE : TRUE;
+    }
+
     auto res = context->redirectionTable().addFile(
         bfs::path(destination), usvfs::RedirectionDataLocal(sourceU8),
         !(flags & LINKFLAG_FAILIFEXISTS));
@@ -728,7 +763,6 @@ static usvfs::shared::TreeFlags convertRedirectionFlags(unsigned int flags)
   return result;
 }
 
-
 BOOL WINAPI VirtualLinkDirectoryStatic(LPCWSTR source, LPCWSTR destination, unsigned int flags)
 {
   // TODO change notification not yet implemented
@@ -752,6 +786,9 @@ BOOL WINAPI VirtualLinkDirectoryStatic(LPCWSTR source, LPCWSTR destination, unsi
           usvfs::shared::FLAG_DIRECTORY | convertRedirectionFlags(flags),
           (flags & LINKFLAG_CREATETARGET) != 0);
 
+    const auto skipDirectories  = context->skipDirectories();
+    const auto skipFileSuffixes = context->skipFileSuffixes();
+
     if ((flags & LINKFLAG_RECURSIVE) != 0) {
       std::wstring sourceP(source);
       std::wstring sourceW      = sourceP + L"\\";
@@ -763,13 +800,36 @@ BOOL WINAPI VirtualLinkDirectoryStatic(LPCWSTR source, LPCWSTR destination, unsi
            winapi::ex::wide::quickFindFiles(sourceP.c_str(), L"*")) {
         if (file.attributes & FILE_ATTRIBUTE_DIRECTORY) {
           if ((file.fileName != L".") && (file.fileName != L"..")) {
+
+            const auto nameU8 = ush::string_cast<std::string>(file.fileName.c_str(),
+                                                              ush::CodePage::UTF8);
+            // Check if the directory should be skipped
+            if (fileNameInSkipDirectories(nameU8, skipDirectories)) {
+              // Fail if we desire to fail when a dir/file is skipped
+              if (flags & LINKFLAG_FAILIFSKIPPED) {
+                spdlog::get("usvfs")->debug("directory '{}' skipped, failing as defined by link flags", nameU8);
+                return FALSE;
+              }
+
+              continue;
+            }
+
             VirtualLinkDirectoryStatic((sourceW + file.fileName).c_str(),
-                                       (destinationW + file.fileName).c_str(),
-                                       flags);
+                                       (destinationW + file.fileName).c_str(), flags);
           }
         } else {
-          std::string nameU8 = ush::string_cast<std::string>(
-              file.fileName.c_str(), ush::CodePage::UTF8);
+          const auto nameU8 = ush::string_cast<std::string>(file.fileName.c_str(), ush::CodePage::UTF8);
+
+          // Check if the file should be skipped
+          if (fileNameInSkipSuffixes(nameU8, skipFileSuffixes)) {
+            // Fail if we desire to fail when a dir/file is skipped
+            if (flags & LINKFLAG_FAILIFSKIPPED) {
+              spdlog::get("usvfs")->debug("file '{}' skipped, failing as defined by link flags", nameU8);
+              return FALSE;
+            }
+
+            continue;
+          }
 
           // TODO could save memory here by storing only the file name for the
           // source and constructing the full name using the parent directory
@@ -878,6 +938,30 @@ VOID WINAPI ClearExecutableBlacklist()
 }
 
 
+VOID WINAPI usvfsAddSkipFileSuffix(LPWSTR fileSuffix)
+{
+  context->addSkipFileSuffix(fileSuffix);
+}
+
+
+VOID WINAPI usvfsClearSkipFileSuffixes()
+{
+  context->clearSkipFileSuffixes();
+}
+
+
+VOID WINAPI usvfsAddSkipDirectory(LPWSTR directory)
+{
+  context->addSkipDirectory(directory);
+}
+
+
+VOID WINAPI usvfsClearSkipDirectories()
+{
+  context->clearSkipDirectories();
+}
+
+
 VOID WINAPI ForceLoadLibrary(LPWSTR processName, LPWSTR libraryPath)
 {
   context->forceLoadLibrary(processName, libraryPath);