1 files changed, 592 insertions, 0 deletions
diff --git a/Driver/Fuse/FuseService.cpp b/Driver/Fuse/FuseService.cpp
new file mode 100644
index 0000000..fda56e0
--- /dev/null
+++ b/Driver/Fuse/FuseService.cpp
@@ -0,0 +1,592 @@
+/*
+ Copyright (c) 2008 TrueCrypt Developers Association. All rights reserved.
+
+ Governed by the TrueCrypt License 3.0 the full text of which is contained in
+ the file License.txt included in TrueCrypt binary and source code distribution
+ packages.
+*/
+
+#define FUSE_USE_VERSION  25
+#include <errno.h>
+#include <fcntl.h>
+#include <fuse.h>
+#include <iostream>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+
+#include "FuseService.h"
+#include "Platform/FileStream.h"
+#include "Platform/MemoryStream.h"
+#include "Platform/Serializable.h"
+#include "Platform/SystemLog.h"
+#include "Platform/Unix/Pipe.h"
+#include "Platform/Unix/Poller.h"
+#include "Volume/EncryptionThreadPool.h"
+#include "Core/Core.h"
+
+namespace TrueCrypt
+{
+	static int fuse_service_access (const char *path, int mask)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return 0;
+	}
+
+	static void *fuse_service_init ()
+	{
+		try
+		{
+			// Termination signals are handled by a separate process to allow clean dismount on shutdown
+			struct sigaction action;
+			Memory::Zero (&action, sizeof (action));
+			action.sa_handler = SIG_IGN;
+
+			sigaction (SIGINT, &action, nullptr);
+			sigaction (SIGQUIT, &action, nullptr);
+			sigaction (SIGTERM, &action, nullptr);
+
+			if (!EncryptionThreadPool::IsRunning())
+				EncryptionThreadPool::Start();
+		}
+		catch (exception &e)
+		{
+			SystemLog::WriteException (e);
+		}
+		catch (...)
+		{
+			SystemLog::WriteException (UnknownException (SRC_POS));
+		}
+
+		return nullptr;
+	}
+
+	static void fuse_service_destroy (void *userdata)
+	{
+		try
+		{
+			FuseService::Dismount();
+		}
+		catch (exception &e)
+		{
+			SystemLog::WriteException (e);
+		}
+		catch (...)
+		{
+			SystemLog::WriteException (UnknownException (SRC_POS));
+		}
+	}
+
+	static int fuse_service_getattr (const char *path, struct stat *statData)
+	{
+		try
+		{
+			Memory::Zero (statData, sizeof(*statData));
+
+			statData->st_uid = FuseService::GetUserId();
+			statData->st_gid = FuseService::GetGroupId();
+			statData->st_atime = time (NULL);
+			statData->st_ctime = time (NULL);
+			statData->st_mtime = time (NULL);
+
+			if (strcmp (path, "/") == 0)
+			{
+				statData->st_mode = S_IFDIR | 0500;
+				statData->st_nlink = 2;
+			}
+			else
+			{
+				if (!FuseService::CheckAccessRights())
+					return -EACCES;
+
+				if (strcmp (path, FuseService::GetVolumeImagePath()) == 0)
+				{
+					statData->st_mode = S_IFREG | 0600;
+					statData->st_nlink = 1;
+					statData->st_size = FuseService::GetVolumeSize();
+				}
+				else if (strcmp (path, FuseService::GetControlPath()) == 0)
+				{
+					statData->st_mode = S_IFREG | 0600;
+					statData->st_nlink = 1;
+					statData->st_size = FuseService::GetVolumeInfo()->Size();
+				}
+				else
+				{
+					return -ENOENT;
+				}
+			}
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return 0;
+	}
+
+	static int fuse_service_opendir (const char *path, struct fuse_file_info *fi)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+
+			if (strcmp (path, "/") != 0)
+				return -ENOENT;
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return 0;
+	}
+
+	static int fuse_service_open (const char *path, struct fuse_file_info *fi)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+
+			if (strcmp (path, FuseService::GetVolumeImagePath()) == 0)
+				return 0;
+
+			if (strcmp (path, FuseService::GetControlPath()) == 0)
+			{
+				fi->direct_io = 1;
+				return 0;
+			}
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+		return -ENOENT;
+	}
+
+	static int fuse_service_read (const char *path, char *buf, size_t size, off_t offset, struct fuse_file_info *fi)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+
+			if (strcmp (path, FuseService::GetVolumeImagePath()) == 0)
+			{
+				try
+				{
+					// Test for read beyond the end of the volume
+					if ((uint64) offset + size > FuseService::GetVolumeSize())
+						size = FuseService::GetVolumeSize() - offset;
+
+					size_t sectorSize = FuseService::GetVolumeSectorSize();
+					if (size % sectorSize != 0 || offset % sectorSize != 0)
+					{
+						// Support for non-sector-aligned read operations is required by some loop device tools
+						// which may analyze the volume image before attaching it as a device
+
+						uint64 alignedOffset = offset - (offset % sectorSize);
+						uint64 alignedSize = size + (offset % sectorSize);
+
+						if (alignedSize % sectorSize != 0)
+							alignedSize += sectorSize - (alignedSize % sectorSize);
+
+						SecureBuffer alignedBuffer (alignedSize);
+
+						FuseService::ReadVolumeSectors (alignedBuffer, alignedOffset);
+						BufferPtr ((byte *) buf, size).CopyFrom (alignedBuffer.GetRange (offset % sectorSize, size));
+					}
+					else
+					{
+						FuseService::ReadVolumeSectors (BufferPtr ((byte *) buf, size), offset);
+					}
+				}
+				catch (MissingVolumeData)
+				{
+					return 0;
+				}
+
+				return size;
+			}
+
+			if (strcmp (path, FuseService::GetControlPath()) == 0)
+			{
+				shared_ptr <Buffer> infoBuf = FuseService::GetVolumeInfo();
+				BufferPtr outBuf ((byte *)buf, size);
+
+				if (offset >= (off_t) infoBuf->Size())
+					return 0;
+
+				if (offset + size > infoBuf->Size())
+					size = infoBuf->Size () - offset;
+
+				outBuf.CopyFrom (infoBuf->GetRange (offset, size));
+				return size;
+			}
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return -ENOENT;
+	}
+
+	static int fuse_service_readdir (const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+
+			if (strcmp (path, "/") != 0)
+				return -ENOENT;
+
+			filler (buf, ".", NULL, 0);
+			filler (buf, "..", NULL, 0);
+			filler (buf, FuseService::GetVolumeImagePath() + 1, NULL, 0);
+			filler (buf, FuseService::GetControlPath() + 1, NULL, 0);
+		}
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return 0;
+	}
+
+	static int fuse_service_write (const char *path, const char *buf, size_t size, off_t offset, struct fuse_file_info *fi)
+	{
+		try
+		{
+			if (!FuseService::CheckAccessRights())
+				return -EACCES;
+
+			if (strcmp (path, FuseService::GetVolumeImagePath()) == 0)
+			{
+				FuseService::WriteVolumeSectors (BufferPtr ((byte *) buf, size), offset);
+				return size;
+			}
+
+			if (strcmp (path, FuseService::GetControlPath()) == 0)
+			{
+				if (FuseService::AuxDeviceInfoReceived())
+					return -EACCES;
+
+				FuseService::ReceiveAuxDeviceInfo (ConstBufferPtr ((const byte *)buf, size));
+				return size;
+			}
+		}
+#ifdef TC_FREEBSD
+		// FreeBSD apparently retries failed write operations forever, which may lead to a system crash.
+		catch (VolumeReadOnly&)
+		{
+			return size;
+		}
+		catch (VolumeProtected&)
+		{
+			return size;
+		}
+#endif
+		catch (...)
+		{
+			return FuseService::ExceptionToErrorCode();
+		}
+
+		return -ENOENT;
+	}
+
+	bool FuseService::CheckAccessRights ()
+	{
+		return fuse_get_context()->uid == 0 || fuse_get_context()->uid == UserId;
+	}
+	
+	void FuseService::CloseMountedVolume ()
+	{
+		if (MountedVolume)
+		{
+			// This process will exit before the use count of MountedVolume reaches zero
+			if (MountedVolume->GetFile().use_count() > 1)
+				MountedVolume->GetFile()->Close();
+
+			if (MountedVolume.use_count() > 1)
+				delete MountedVolume.get();
+
+			MountedVolume.reset();
+		}
+	}
+
+	void FuseService::Dismount ()
+	{
+		CloseMountedVolume();
+
+		if (EncryptionThreadPool::IsRunning())
+			EncryptionThreadPool::Stop();
+	}
+
+	int FuseService::ExceptionToErrorCode ()
+	{
+		try
+		{
+			throw;
+		}
+		catch (std::bad_alloc)
+		{
+			return -ENOMEM;
+		}
+		catch (ParameterIncorrect &e)
+		{
+			SystemLog::WriteException (e);
+			return -EINVAL;
+		}
+		catch (VolumeProtected&)
+		{
+			return -EPERM;
+		}
+		catch (VolumeReadOnly&)
+		{
+			return -EPERM;
+		}
+		catch (SystemException &e)
+		{
+			SystemLog::WriteException (e);
+			return -static_cast <int> (e.GetErrorCode());
+		}
+		catch (std::exception &e)
+		{
+			SystemLog::WriteException (e);
+			return -EINTR;
+		}
+		catch (...)
+		{
+			SystemLog::WriteException (UnknownException (SRC_POS));
+			return -EINTR;
+		}
+	}
+
+	shared_ptr <Buffer> FuseService::GetVolumeInfo ()
+	{
+		shared_ptr <Stream> stream (new MemoryStream);
+
+		{
+			ScopeLock lock (OpenVolumeInfoMutex);
+
+			OpenVolumeInfo.Set (*MountedVolume);
+			OpenVolumeInfo.SlotNumber = SlotNumber;
+
+			OpenVolumeInfo.Serialize (stream);
+		}
+
+		ConstBufferPtr infoBuf = dynamic_cast <MemoryStream&> (*stream);
+		shared_ptr <Buffer> outBuf (new Buffer (infoBuf.Size()));
+		outBuf->CopyFrom (infoBuf);
+
+		return outBuf;
+	}
+	
+	const char *FuseService::GetVolumeImagePath ()
+	{
+#ifdef TC_MACOSX
+		return "/volume.dmg";
+#else
+		return "/volume";
+#endif
+	}
+
+	uint64 FuseService::GetVolumeSize ()
+	{
+		if (!MountedVolume)
+			throw NotInitialized (SRC_POS);
+
+		return MountedVolume->GetSize();
+	}
+
+	void FuseService::Mount (shared_ptr <Volume> openVolume, VolumeSlotNumber slotNumber, const string &fuseMountPoint)
+	{
+		list <string> args;
+		args.push_back (FuseService::GetDeviceType());
+		args.push_back (fuseMountPoint);
+
+#ifdef TC_MACOSX
+		args.push_back ("-o");
+		args.push_back ("noping_diskarb");
+		args.push_back ("-o");
+		args.push_back ("nobrowse");
+
+		if (getuid() == 0 || geteuid() == 0)
+#endif
+		{
+			args.push_back ("-o");
+			args.push_back ("allow_other");
+		}
+		
+		ExecFunctor execFunctor (openVolume, slotNumber);
+		Process::Execute ("fuse", args, -1, &execFunctor);
+
+		for (int t = 0; true; t++)
+		{
+			try
+			{
+				if (FilesystemPath (fuseMountPoint + FuseService::GetControlPath()).GetType() == FilesystemPathType::File)
+					break;
+			}
+			catch (...)
+			{
+				if (t > 50)
+					throw;
+
+				Thread::Sleep (100);
+			}
+		}
+	}
+
+	void FuseService::ReadVolumeSectors (const BufferPtr &buffer, uint64 byteOffset)
+	{
+		if (!MountedVolume)
+			throw NotInitialized (SRC_POS);
+
+		MountedVolume->ReadSectors (buffer, byteOffset);
+	}
+
+	void FuseService::ReceiveAuxDeviceInfo (const ConstBufferPtr &buffer)
+	{
+		shared_ptr <Stream> stream (new MemoryStream (buffer));
+		Serializer sr (stream);
+
+		ScopeLock lock (OpenVolumeInfoMutex);
+		OpenVolumeInfo.VirtualDevice = sr.DeserializeString ("VirtualDevice");
+		OpenVolumeInfo.LoopDevice = sr.DeserializeString ("LoopDevice");
+	}
+
+	void FuseService::SendAuxDeviceInfo (const DirectoryPath &fuseMountPoint, const DevicePath &virtualDevice, const DevicePath &loopDevice)
+	{
+		File fuseServiceControl;
+		fuseServiceControl.Open (string (fuseMountPoint) + GetControlPath(), File::OpenWrite);
+
+		shared_ptr <Stream> stream (new MemoryStream);
+		Serializer sr (stream);
+
+		sr.Serialize ("VirtualDevice", string (virtualDevice));
+		sr.Serialize ("LoopDevice", string (loopDevice));
+		fuseServiceControl.Write (dynamic_cast <MemoryStream&> (*stream));
+	}
+
+	void FuseService::WriteVolumeSectors (const ConstBufferPtr &buffer, uint64 byteOffset)
+	{
+		if (!MountedVolume)
+			throw NotInitialized (SRC_POS);
+
+		MountedVolume->WriteSectors (buffer, byteOffset);
+	}
+	
+	void FuseService::OnSignal (int signal)
+	{
+		try
+		{
+			shared_ptr <VolumeInfo> volume = Core->GetMountedVolume (SlotNumber);
+			
+			if (volume)
+				Core->DismountVolume (volume, true);
+		}
+		catch (...) { }
+
+		_exit (0);
+	}
+
+	void FuseService::ExecFunctor::operator() (int argc, char *argv[])
+	{
+		struct timeval tv;
+		gettimeofday (&tv, NULL);
+		FuseService::OpenVolumeInfo.SerialInstanceNumber = (uint64)tv.tv_sec * 1000000ULL + tv.tv_usec;
+
+		FuseService::MountedVolume = MountedVolume;
+		FuseService::SlotNumber = SlotNumber;
+
+		FuseService::UserId = getuid();
+		FuseService::GroupId = getgid();
+
+		if (getenv ("SUDO_UID"))
+		{
+			try
+			{
+				string s (getenv ("SUDO_UID"));
+				FuseService::UserId = static_cast <uid_t> (StringConverter::ToUInt64 (s));
+
+				if (getenv ("SUDO_GID"))
+				{
+					s = getenv ("SUDO_GID");
+					FuseService::GroupId = static_cast <gid_t> (StringConverter::ToUInt64 (s));
+				}
+			}
+			catch (...) { }
+		}
+
+		static fuse_operations fuse_service_oper;
+
+		fuse_service_oper.access = fuse_service_access;
+		fuse_service_oper.destroy = fuse_service_destroy;
+		fuse_service_oper.getattr = fuse_service_getattr;
+		fuse_service_oper.init = fuse_service_init;
+		fuse_service_oper.open = fuse_service_open;
+		fuse_service_oper.opendir = fuse_service_opendir;
+		fuse_service_oper.read = fuse_service_read;
+		fuse_service_oper.readdir = fuse_service_readdir;
+		fuse_service_oper.write = fuse_service_write;
+
+		// Create a new session
+		setsid ();
+
+		// Fork handler of termination signals
+		SignalHandlerPipe.reset (new Pipe);
+
+		int forkedPid = fork();
+		throw_sys_if (forkedPid == -1);
+
+		if (forkedPid == 0)
+		{
+			CloseMountedVolume();
+
+			struct sigaction action;
+			Memory::Zero (&action, sizeof (action));
+			action.sa_handler = OnSignal;
+
+			sigaction (SIGINT, &action, nullptr);
+			sigaction (SIGQUIT, &action, nullptr);
+			sigaction (SIGTERM, &action, nullptr);
+
+			// Wait for the exit of the main service
+			byte buf[1];
+			if (read (SignalHandlerPipe->GetReadFD(), buf, sizeof (buf))) { } // Errors ignored
+
+			_exit (0);
+		}
+
+		SignalHandlerPipe->GetWriteFD();
+
+		_exit (fuse_main (argc, argv, &fuse_service_oper));
+	}
+
+	VolumeInfo FuseService::OpenVolumeInfo;
+	Mutex FuseService::OpenVolumeInfoMutex;
+	shared_ptr <Volume> FuseService::MountedVolume;
+	VolumeSlotNumber FuseService::SlotNumber;
+	uid_t FuseService::UserId;
+	gid_t FuseService::GroupId;
+	auto_ptr <Pipe> FuseService::SignalHandlerPipe;
+}