/* Derived from source code of TrueCrypt 7.1a, which is Copyright (c) 2008-2012 TrueCrypt Developers Association and which is governed by the TrueCrypt License 3.0. Modifications and additions to the original source code (contained in this file) and all other portions of this file are Copyright (c) 2013-2017 IDRIX and are governed by the Apache License 2.0 the full text of which is contained in the file License.txt included in VeraCrypt 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 VeraCrypt { 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; unique_ptr <Pipe> FuseService::SignalHandlerPipe; }