| // Copyright (c) 2017 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "sql/vfs_wrapper.h" |
| |
| #include <algorithm> |
| #include <string> |
| #include <vector> |
| |
| #include "base/debug/leak_annotations.h" |
| #include "base/logging.h" |
| #include "base/memory/ptr_util.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/strings/string_piece.h" |
| |
| #if defined(OS_MACOSX) && !defined(OS_IOS) |
| #include <CoreFoundation/CoreFoundation.h> |
| #include <CoreServices/CoreServices.h> |
| |
| #include "base/mac/mac_util.h" |
| #include "base/mac/scoped_cftyperef.h" |
| #endif |
| |
| namespace sql { |
| namespace { |
| |
| // https://www.sqlite.org/vfs.html - documents the overall VFS system. |
| // |
| // https://www.sqlite.org/c3ref/vfs.html - VFS methods. This code tucks the |
| // wrapped VFS pointer into the wrapper's pAppData pointer. |
| // |
| // https://www.sqlite.org/c3ref/file.html - instance of an open file. This code |
| // allocates a VfsFile for this, which contains a pointer to the wrapped file. |
| // Idiomatic SQLite would take the wrapped VFS szOsFile and increase it to store |
| // additional data as a prefix. |
| |
| sqlite3_vfs* GetWrappedVfs(sqlite3_vfs* wrapped_vfs) { |
| return static_cast<sqlite3_vfs*>(wrapped_vfs->pAppData); |
| } |
| |
| // NOTE(shess): This structure is allocated by SQLite using malloc. Do not add |
| // C++ objects, they will not be correctly constructed and destructed. Instead, |
| // manually manage a pointer to a C++ object in Open() and Close(). |
| struct VfsFile { |
| const sqlite3_io_methods* methods; |
| sqlite3_file* wrapped_file; |
| }; |
| |
| VfsFile* AsVfsFile(sqlite3_file* wrapper_file) { |
| return reinterpret_cast<VfsFile*>(wrapper_file); |
| } |
| |
| sqlite3_file* GetWrappedFile(sqlite3_file* wrapper_file) { |
| return AsVfsFile(wrapper_file)->wrapped_file; |
| } |
| |
| int Close(sqlite3_file* sqlite_file) |
| { |
| VfsFile* file = AsVfsFile(sqlite_file); |
| |
| int r = file->wrapped_file->pMethods->xClose(file->wrapped_file); |
| sqlite3_free(file->wrapped_file); |
| memset(file, '\0', sizeof(*file)); |
| return r; |
| } |
| |
| int Read(sqlite3_file* sqlite_file, void* buf, int amt, sqlite3_int64 ofs) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xRead(wrapped_file, buf, amt, ofs); |
| } |
| |
| int Write(sqlite3_file* sqlite_file, const void* buf, int amt, |
| sqlite3_int64 ofs) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xWrite(wrapped_file, buf, amt, ofs); |
| } |
| |
| int Truncate(sqlite3_file* sqlite_file, sqlite3_int64 size) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xTruncate(wrapped_file, size); |
| } |
| |
| int Sync(sqlite3_file* sqlite_file, int flags) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xSync(wrapped_file, flags); |
| } |
| |
| int FileSize(sqlite3_file* sqlite_file, sqlite3_int64* size) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xFileSize(wrapped_file, size); |
| } |
| |
| int Lock(sqlite3_file* sqlite_file, int file_lock) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xLock(wrapped_file, file_lock); |
| } |
| |
| int Unlock(sqlite3_file* sqlite_file, int file_lock) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xUnlock(wrapped_file, file_lock); |
| } |
| |
| int CheckReservedLock(sqlite3_file* sqlite_file, int* result) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xCheckReservedLock(wrapped_file, result); |
| } |
| |
| int FileControl(sqlite3_file* sqlite_file, int op, void* arg) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xFileControl(wrapped_file, op, arg); |
| } |
| |
| int SectorSize(sqlite3_file* sqlite_file) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xSectorSize(wrapped_file); |
| } |
| |
| int DeviceCharacteristics(sqlite3_file* sqlite_file) |
| { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xDeviceCharacteristics(wrapped_file); |
| } |
| |
| int ShmMap(sqlite3_file *sqlite_file, int region, int size, |
| int extend, void volatile **pp) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xShmMap( |
| wrapped_file, region, size, extend, pp); |
| } |
| |
| int ShmLock(sqlite3_file *sqlite_file, int ofst, int n, int flags) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xShmLock(wrapped_file, ofst, n, flags); |
| } |
| |
| void ShmBarrier(sqlite3_file *sqlite_file) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| wrapped_file->pMethods->xShmBarrier(wrapped_file); |
| } |
| |
| int ShmUnmap(sqlite3_file *sqlite_file, int del) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xShmUnmap(wrapped_file, del); |
| } |
| |
| int Fetch(sqlite3_file *sqlite_file, sqlite3_int64 off, int amt, void **pp) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xFetch(wrapped_file, off, amt, pp); |
| } |
| |
| int Unfetch(sqlite3_file *sqlite_file, sqlite3_int64 off, void *p) { |
| sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
| return wrapped_file->pMethods->xUnfetch(wrapped_file, off, p); |
| } |
| |
| #if defined(OS_MACOSX) && !defined(OS_IOS) |
| // Helper to convert a POSIX path into a CoreFoundation path. |
| base::ScopedCFTypeRef<CFURLRef> CFURLRefForPath(const char* path){ |
| base::ScopedCFTypeRef<CFStringRef> urlString( |
| CFStringCreateWithFileSystemRepresentation(kCFAllocatorDefault, path)); |
| base::ScopedCFTypeRef<CFURLRef> url( |
| CFURLCreateWithFileSystemPath(kCFAllocatorDefault, urlString, |
| kCFURLPOSIXPathStyle, FALSE)); |
| return url; |
| } |
| #endif |
| |
| int Open(sqlite3_vfs* vfs, const char* file_name, sqlite3_file* wrapper_file, |
| int desired_flags, int* used_flags) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| |
| sqlite3_file* wrapped_file = static_cast<sqlite3_file*>( |
| sqlite3_malloc(wrapped_vfs->szOsFile)); |
| if (!wrapped_file) |
| return SQLITE_NOMEM; |
| |
| // NOTE(shess): SQLite's unixOpen() makes assumptions about the structure of |
| // |file_name|. Do not pass a local copy, here, only the passed-in value. |
| int rc = wrapped_vfs->xOpen(wrapped_vfs, |
| file_name, wrapped_file, |
| desired_flags, used_flags); |
| if (rc != SQLITE_OK) { |
| sqlite3_free(wrapped_file); |
| return rc; |
| } |
| // NOTE(shess): Any early exit from here needs to call xClose() on |
| // |wrapped_file|. |
| |
| #if defined(OS_MACOSX) && !defined(OS_IOS) |
| // When opening journal files, propagate time-machine exclusion from db. |
| static int kJournalFlags = |
| SQLITE_OPEN_MAIN_JOURNAL | SQLITE_OPEN_TEMP_JOURNAL | |
| SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_MASTER_JOURNAL; |
| if (file_name && (desired_flags & kJournalFlags)) { |
| // https://www.sqlite.org/c3ref/vfs.html indicates that the journal path |
| // will have a "-suffix". |
| size_t dash_index = base::StringPiece(file_name).rfind('-'); |
| if (dash_index != base::StringPiece::npos) { |
| std::string db_name(file_name, dash_index); |
| base::ScopedCFTypeRef<CFURLRef> db_url(CFURLRefForPath(db_name.c_str())); |
| if (CSBackupIsItemExcluded(db_url, nullptr)) { |
| base::ScopedCFTypeRef<CFURLRef> journal_url(CFURLRefForPath(file_name)); |
| CSBackupSetItemExcluded(journal_url, TRUE, FALSE); |
| } |
| } |
| } |
| #endif |
| |
| // |iVersion| determines what methods SQLite may call on the instance. |
| // Having the methods which can't be proxied return an error may cause SQLite |
| // to operate differently than if it didn't call those methods at all. To be |
| // on the safe side, the wrapper sqlite3_io_methods version perfectly matches |
| // the version of the wrapped files. |
| // |
| // At a first glance, it might be tempting to simplify the code by |
| // restricting wrapping support to VFS version 3. However, this would fail |
| // on Fuchsia and might fail on Mac. |
| // |
| // On Mac, SQLite built with SQLITE_ENABLE_LOCKING_STYLE ends up using a VFS |
| // that dynamically dispatches between a few variants of sqlite3_io_methods, |
| // based on whether the opened database is on a local or on a remote (AFS, |
| // NFS) filesystem. Some variants return a VFS version 1 structure. |
| // |
| // Fuchsia doesn't implement POSIX locking, so it always uses dot-style |
| // locking, which returns VFS version 1 files. |
| VfsFile* file = AsVfsFile(wrapper_file); |
| file->wrapped_file = wrapped_file; |
| if (wrapped_file->pMethods->iVersion == 1) { |
| static const sqlite3_io_methods io_methods = { |
| 1, |
| Close, |
| Read, |
| Write, |
| Truncate, |
| Sync, |
| FileSize, |
| Lock, |
| Unlock, |
| CheckReservedLock, |
| FileControl, |
| SectorSize, |
| DeviceCharacteristics, |
| }; |
| file->methods = &io_methods; |
| } else if (wrapped_file->pMethods->iVersion == 2) { |
| static const sqlite3_io_methods io_methods = { |
| 2, |
| Close, |
| Read, |
| Write, |
| Truncate, |
| Sync, |
| FileSize, |
| Lock, |
| Unlock, |
| CheckReservedLock, |
| FileControl, |
| SectorSize, |
| DeviceCharacteristics, |
| // Methods above are valid for version 1. |
| ShmMap, |
| ShmLock, |
| ShmBarrier, |
| ShmUnmap, |
| }; |
| file->methods = &io_methods; |
| } else { |
| static const sqlite3_io_methods io_methods = { |
| 3, |
| Close, |
| Read, |
| Write, |
| Truncate, |
| Sync, |
| FileSize, |
| Lock, |
| Unlock, |
| CheckReservedLock, |
| FileControl, |
| SectorSize, |
| DeviceCharacteristics, |
| // Methods above are valid for version 1. |
| ShmMap, |
| ShmLock, |
| ShmBarrier, |
| ShmUnmap, |
| // Methods above are valid for version 2. |
| Fetch, |
| Unfetch, |
| }; |
| file->methods = &io_methods; |
| } |
| return SQLITE_OK; |
| } |
| |
| int Delete(sqlite3_vfs* vfs, const char* file_name, int sync_dir) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xDelete(wrapped_vfs, file_name, sync_dir); |
| } |
| |
| int Access(sqlite3_vfs* vfs, const char* file_name, int flag, int* res) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xAccess(wrapped_vfs, file_name, flag, res); |
| } |
| |
| int FullPathname(sqlite3_vfs* vfs, const char* relative_path, |
| int buf_size, char* absolute_path) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xFullPathname( |
| wrapped_vfs, relative_path, buf_size, absolute_path); |
| } |
| |
| void* DlOpen(sqlite3_vfs* vfs, const char* filename) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xDlOpen(wrapped_vfs, filename); |
| } |
| |
| void DlError(sqlite3_vfs* vfs, int buf_size, char* error_buffer) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| wrapped_vfs->xDlError(wrapped_vfs, buf_size, error_buffer); |
| } |
| |
| void(*DlSym(sqlite3_vfs* vfs, void* handle, const char* sym))(void) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xDlSym(wrapped_vfs, handle, sym); |
| } |
| |
| void DlClose(sqlite3_vfs* vfs, void* handle) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| wrapped_vfs->xDlClose(wrapped_vfs, handle); |
| } |
| |
| int Randomness(sqlite3_vfs* vfs, int buf_size, char* buffer) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xRandomness(wrapped_vfs, buf_size, buffer); |
| } |
| |
| int Sleep(sqlite3_vfs* vfs, int microseconds) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xSleep(wrapped_vfs, microseconds); |
| } |
| |
| int CurrentTime(sqlite3_vfs* vfs, double* now) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xCurrentTime(wrapped_vfs, now); |
| } |
| |
| int GetLastError(sqlite3_vfs* vfs, int e, char* s) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xGetLastError(wrapped_vfs, e, s); |
| } |
| |
| int CurrentTimeInt64(sqlite3_vfs* vfs, sqlite3_int64* now) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xCurrentTimeInt64(wrapped_vfs, now); |
| } |
| |
| int SetSystemCall(sqlite3_vfs* vfs, const char* name, |
| sqlite3_syscall_ptr func) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xSetSystemCall(wrapped_vfs, name, func); |
| } |
| |
| sqlite3_syscall_ptr GetSystemCall(sqlite3_vfs* vfs, const char* name) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xGetSystemCall(wrapped_vfs, name); |
| } |
| |
| const char* NextSystemCall(sqlite3_vfs* vfs, const char* name) { |
| sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
| return wrapped_vfs->xNextSystemCall(wrapped_vfs, name); |
| } |
| |
| } // namespace |
| |
| sqlite3_vfs* VFSWrapper() { |
| const char* kVFSName = "VFSWrapper"; |
| |
| // Return existing version if already registered. |
| { |
| sqlite3_vfs* vfs = sqlite3_vfs_find(kVFSName); |
| if (vfs) |
| return vfs; |
| } |
| |
| // Get the default VFS for this platform. If no default VFS, give up. |
| sqlite3_vfs* wrapped_vfs = sqlite3_vfs_find(nullptr); |
| if (!wrapped_vfs) |
| return nullptr; |
| |
| std::unique_ptr<sqlite3_vfs, std::function<void(sqlite3_vfs*)>> wrapper_vfs( |
| static_cast<sqlite3_vfs*>(sqlite3_malloc(sizeof(sqlite3_vfs))), |
| [](sqlite3_vfs* v) { |
| sqlite3_free(v); |
| }); |
| memset(wrapper_vfs.get(), '\0', sizeof(sqlite3_vfs)); |
| |
| // VFS implementations should always work with a SQLite that only knows about |
| // earlier versions. |
| wrapper_vfs->iVersion = std::min(wrapped_vfs->iVersion, 3); |
| |
| // Caller of xOpen() allocates this much space. |
| wrapper_vfs->szOsFile = sizeof(VfsFile); |
| |
| wrapper_vfs->mxPathname = wrapped_vfs->mxPathname; |
| wrapper_vfs->pNext = nullptr; |
| wrapper_vfs->zName = kVFSName; |
| |
| // Keep a reference to the wrapped vfs for use in methods. |
| wrapper_vfs->pAppData = wrapped_vfs; |
| |
| // VFS methods. |
| wrapper_vfs->xOpen = &Open; |
| wrapper_vfs->xDelete = &Delete; |
| wrapper_vfs->xAccess = &Access; |
| wrapper_vfs->xFullPathname = &FullPathname; |
| wrapper_vfs->xDlOpen = &DlOpen; |
| wrapper_vfs->xDlError = &DlError; |
| wrapper_vfs->xDlSym = &DlSym; |
| wrapper_vfs->xDlClose = &DlClose; |
| wrapper_vfs->xRandomness = &Randomness; |
| wrapper_vfs->xSleep = &Sleep; |
| // |xCurrentTime| is null when SQLite is built with SQLITE_OMIT_DEPRECATED. |
| wrapper_vfs->xCurrentTime = |
| (wrapped_vfs->xCurrentTime ? &CurrentTime : nullptr); |
| wrapper_vfs->xGetLastError = &GetLastError; |
| // The methods above are in version 1 of sqlite_vfs. |
| DCHECK(wrapped_vfs->xCurrentTimeInt64); |
| wrapper_vfs->xCurrentTimeInt64 = &CurrentTimeInt64; |
| // The methods above are in version 2 of sqlite_vfs. |
| DCHECK(wrapped_vfs->xSetSystemCall); |
| wrapper_vfs->xSetSystemCall = &SetSystemCall; |
| DCHECK(wrapped_vfs->xGetSystemCall); |
| wrapper_vfs->xGetSystemCall = &GetSystemCall; |
| DCHECK(wrapped_vfs->xNextSystemCall); |
| wrapper_vfs->xNextSystemCall = &NextSystemCall; |
| // The methods above are in version 3 of sqlite_vfs. |
| |
| if (SQLITE_OK == sqlite3_vfs_register(wrapper_vfs.get(), 0)) { |
| ANNOTATE_LEAKING_OBJECT_PTR(wrapper_vfs.get()); |
| wrapper_vfs.release(); |
| } |
| |
| return sqlite3_vfs_find(kVFSName); |
| } |
| |
| } // namespace sql |