Implement CryOpenFile and infrastructure around it

src/CryFuse.cpp

@@ -29,7 +29,7 @@ CryFuse::CryFuse(CryDevice *device)
 
 int CryFuse::getattr(const path &path, struct stat *stbuf) {
   try {
-    _device->LoadFromPath(path)->stat(stbuf);
+    _device->lstat(path, stbuf);
     return 0;
   } catch(cryfs::CryErrnoException &e) {
     return -e.getErrno();
@@ -47,8 +47,12 @@ int CryFuse::fgetattr(const path &path, struct stat *stbuf, fuse_file_info *file
     return getattr(path, stbuf);
   }
 
-  int retstat = fstat(fileinfo->fh, stbuf);
-  return errcode_map(retstat);
+  try {
+	_device->fstat(fileinfo->fh, stbuf);
+	return 0;
+  } catch(cryfs::CryErrnoException &e) {
+	  return -e.getErrno();
+  }
 }
 
 int CryFuse::readlink(const path &path, char *buf, size_t size) {

src/cryfs_lib/CMakeLists.txt

@@ -1,3 +1,3 @@
-add_library(cryfs_lib CryDevice.cpp CryDir.cpp CryErrnoException.cpp CryFile.cpp CryNode.cpp)
+add_library(cryfs_lib CryDevice.cpp CryDir.cpp CryErrnoException.cpp CryFile.cpp CryNode.cpp CryOpenFile.cpp CryOpenFileList.cpp)
 
 target_link_libraries(cryfs_lib boost_filesystem)

src/cryfs_lib/CryDevice.cpp

@@ -4,7 +4,9 @@
 
 #include "CryDir.h"
 #include "CryFile.h"
+#include "CryOpenFile.h"
 #include "CryErrnoException.h"
+#include "utils/pointer.h"
 
 using namespace cryfs;
 
@@ -12,13 +14,13 @@ using std::unique_ptr;
 using std::make_unique;
 
 CryDevice::CryDevice(const bf::path &rootdir)
-  :_rootdir(rootdir) {
+  :_rootdir(rootdir), _open_files() {
 }
 
 CryDevice::~CryDevice() {
 }
 
-unique_ptr<CryNode> CryDevice::LoadFromPath(const bf::path &path) {
+unique_ptr<CryNode> CryDevice::Load(const bf::path &path) {
   auto real_path = RootDir() / path;
   if(bf::is_directory(real_path)) {
     return make_unique<CryDir>(this, path);
@@ -28,3 +30,25 @@ unique_ptr<CryNode> CryDevice::LoadFromPath(const bf::path &path) {
 
   throw CryErrnoException(ENOENT);
 }
+
+std::unique_ptr<CryFile> CryDevice::LoadFile(const bf::path &path) {
+  auto node = Load(path);
+  auto file = dynamic_pointer_move<CryFile>(node);
+  if (!file) {
+	throw CryErrnoException(EISDIR);
+  }
+  return file;
+}
+
+int CryDevice::OpenFile(const bf::path &path, int flags) {
+  auto file = LoadFile(path);
+  return _open_files.open(*file, flags);
+}
+
+void CryDevice::lstat(const bf::path &path, struct ::stat *stbuf) {
+  Load(path)->stat(stbuf);
+}
+
+void CryDevice::fstat(int descriptor, struct ::stat *stbuf) {
+  _open_files.get(descriptor)->stat(stbuf);
+}

src/cryfs_lib/CryDevice.h

@@ -3,11 +3,15 @@
 #define CRYFS_LIB_CRYDEVICE_H_
 
 #include <boost/filesystem.hpp>
-#include "utils/macros.h"
+#include <cryfs_lib/CryOpenFileList.h>
 #include <memory>
+#include <sys/stat.h>
+
+#include "utils/macros.h"
 
 namespace cryfs {
 class CryNode;
+class CryFile;
 
 namespace bf = boost::filesystem;
 
@@ -16,12 +20,16 @@ public:
 	CryDevice(const bf::path &rootdir);
 	virtual ~CryDevice();
 
-	std::unique_ptr<CryNode> LoadFromPath(const bf::path &path);
-	//std::unique_ptr<const CryNode> LoadFromPath(const bf::path &path) const;
+	int OpenFile(const bf::path &path, int flags);
+	void lstat(const bf::path &path, struct ::stat *stbuf);
+	void fstat(int descriptor, struct ::stat *stbuf);
 
 	const bf::path &RootDir() const;
 private:
+	std::unique_ptr<CryNode> Load(const bf::path &path);
+	std::unique_ptr<CryFile> LoadFile(const bf::path &path);
 	const bf::path _rootdir;
+	CryOpenFileList _open_files;
 
   DISALLOW_COPY_AND_ASSIGN(CryDevice);
 };

src/cryfs_lib/CryDir.h

@@ -3,6 +3,7 @@
 #define CRYFS_LIB_CRYDIR_H_
 
 #include "CryNode.h"
+#include "utils/macros.h"
 
 namespace cryfs {
 class CryDevice;
@@ -11,6 +12,8 @@ class CryDir: public CryNode {
 public:
   CryDir(CryDevice *device, const bf::path &path);
   virtual ~CryDir();
+private:
+  DISALLOW_COPY_AND_ASSIGN(CryDir);
 };
 
 } /* namespace cryfs */

src/cryfs_lib/CryFile.cpp

@@ -1,5 +1,8 @@
 #include "CryFile.h"
-#include "CryErrnoException.h"
+#include "CryOpenFile.h"
+
+using std::unique_ptr;
+using std::make_unique;
 
 namespace cryfs {
 
@@ -10,4 +13,8 @@ CryFile::CryFile(CryDevice *device, const bf::path &path)
 CryFile::~CryFile() {
 }
 
+std::unique_ptr<CryOpenFile> CryFile::open(int flags) const {
+  return make_unique<CryOpenFile>(base_path(), flags);
+}
+
 } /* namespace cryfs */

src/cryfs_lib/CryFile.h

@@ -6,13 +6,19 @@
 
 #include "CryDevice.h"
 #include "CryNode.h"
+#include "utils/macros.h"
 
 namespace cryfs {
+class CryOpenFile;
 
 class CryFile: public CryNode {
 public:
   CryFile(CryDevice *device, const bf::path &path);
   virtual ~CryFile();
+
+  std::unique_ptr<CryOpenFile> open(int flags) const;
+private:
+  DISALLOW_COPY_AND_ASSIGN(CryFile);
 };
 
 } /* namespace cryfs */

src/cryfs_lib/CryNode.cpp

@@ -12,7 +12,7 @@ CryNode::CryNode(CryDevice *device, const bf::path &path)
 CryNode::~CryNode() {
 }
 
-void CryNode::stat(struct stat *result) const {
+void CryNode::stat(struct ::stat *result) const {
   int retval = ::lstat(base_path().c_str(), result);
   CHECK_RETVAL(retval);
 }

src/cryfs_lib/CryNode.h

@@ -17,11 +17,10 @@ public:
   CryNode(CryDevice *device, const bf::path &path);
   virtual ~CryNode();
 
-  void stat(struct stat *result) const;
+  void stat(struct ::stat *result) const;
 
 protected:
   bf::path base_path() const;
-  CryDevice *device();
 
 private:
   CryDevice *const _device;

src/cryfs_lib/CryOpenFile.cpp

@@ -0,0 +1,24 @@
+#include <cryfs_lib/CryOpenFile.h>
+
+#include <sys/types.h>
+#include <fcntl.h>
+
+#include "CryErrnoException.h"
+
+using namespace cryfs;
+
+CryOpenFile::CryOpenFile(const bf::path &path, int flags)
+  :_descriptor(::open(path.c_str(), flags)) {
+  CHECK_RETVAL(_descriptor);
+}
+
+CryOpenFile::~CryOpenFile() {
+  int retval = close(_descriptor);
+  CHECK_RETVAL(retval);
+}
+
+void CryOpenFile::stat(struct ::stat *result) const {
+  int retval = ::fstat(_descriptor, result);
+  CHECK_RETVAL(retval);
+}
+

src/cryfs_lib/CryOpenFile.h

@@ -0,0 +1,27 @@
+#ifndef CRYFS_LIB_CRYOPENFILE_H_
+#define CRYFS_LIB_CRYOPENFILE_H_
+
+#include <boost/filesystem.hpp>
+#include <sys/stat.h>
+
+#include "utils/macros.h"
+
+namespace cryfs {
+
+namespace bf = boost::filesystem;
+
+class CryOpenFile {
+public:
+  CryOpenFile(const bf::path &path, int flags);
+  virtual ~CryOpenFile();
+
+  void stat(struct ::stat *result) const;
+private:
+  int _descriptor;
+
+  DISALLOW_COPY_AND_ASSIGN(CryOpenFile);
+};
+
+}
+
+#endif /* CRYFS_LIB_CRYOPENFILE_H_ */

src/cryfs_lib/CryOpenFileList.cpp

@@ -0,0 +1,28 @@
+#include <cryfs_lib/CryOpenFileList.h>
+#include "CryFile.h"
+#include "CryOpenFile.h"
+
+using namespace cryfs;
+
+CryOpenFileList::CryOpenFileList()
+  :_open_files() {
+}
+
+CryOpenFileList::~CryOpenFileList() {
+}
+
+int CryOpenFileList::open(const CryFile &file, int flags) {
+  //TODO Reuse descriptors
+  int desc = _open_files.size();
+  _open_files[desc] = file.open(flags);
+  return desc;
+}
+
+CryOpenFile *CryOpenFileList::get(int descriptor) {
+  return _open_files.at(descriptor).get();
+}
+
+void CryOpenFileList::close(int descriptor) {
+  //The destructor of the stored CryFile::OpenFile closes the file
+  _open_files.erase(descriptor);
+}

src/cryfs_lib/CryOpenFileList.h

@@ -0,0 +1,29 @@
+#ifndef CRYFS_LIB_CRYOPENFILELIST_H_
+#define CRYFS_LIB_CRYOPENFILELIST_H_
+
+#include <map>
+#include <memory>
+#include "utils/macros.h"
+
+namespace cryfs {
+class CryFile;
+class CryOpenFile;
+
+class CryOpenFileList {
+public:
+  CryOpenFileList();
+  virtual ~CryOpenFileList();
+
+  int open(const CryFile &rhs, int flags);
+  CryOpenFile *get(int descriptor);
+  void close(int descriptor);
+
+private:
+  std::map<int, std::unique_ptr<CryOpenFile>> _open_files;
+
+  DISALLOW_COPY_AND_ASSIGN(CryOpenFileList);
+};
+
+}
+
+#endif /* CRYFS_LIB_CRYOPENFILELIST_H_ */

src/cryfs_lib/utils/pointer.h

@@ -0,0 +1,18 @@
+#pragma once
+#ifndef CRYFS_LIB_UTILS_POINTER_H_
+#define CRYFS_LIB_UTILS_POINTER_H_
+
+#include <memory>
+
+namespace cryfs {
+  template<typename DST, typename SRC>
+  inline std::unique_ptr<DST> dynamic_pointer_move(std::unique_ptr<SRC> &source) {
+	DST *casted = dynamic_cast<DST*>(source.get());
+	if (casted != nullptr) {
+      source.release();
+	}
+	return std::unique_ptr<DST>(casted);
+  }
+}
+
+#endif