namespace encfs {
static Interface MemBlockFileIO_iface =
makeInterface("FileIO/MemBlock", 1, 0, 0);
MemBlockFileIO::MemBlockFileIO(int blockSize, const FSConfigPtr& cfg)
: BlockFileIO(blockSize, cfg), impl(new MemFileIO(0)) {}
MemBlockFileIO::~MemBlockFileIO() {}
Interface MemBlockFileIO::interface() const { return MemBlockFileIO_iface; }
void MemBlockFileIO::setFileName(const char* name) {
return impl->setFileName(name);
}
const char* MemBlockFileIO::getFileName() const { return impl->getFileName(); }
int MemBlockFileIO::open(int flags) { return impl->open(flags); }
int MemBlockFileIO::getAttr(struct stat* stbuf) const {
return impl->getAttr(stbuf);
}
off_t MemBlockFileIO::getSize() const { return impl->getSize(); }
ssize_t MemBlockFileIO::readOneBlock(const IORequest& req) const {
return impl->read(req);
}
bool MemBlockFileIO::writeOneBlock(const IORequest& req) {
return impl->write(req);
}
int MemBlockFileIO::truncate(off_t size) { return impl->truncate(size); }
bool MemBlockFileIO::isWritable() const { return impl->isWritable(); }
} // namespace encfs
namespace encfs {
static Interface RawFileIO_iface = makeInterface("FileIO/Raw", 1, 0, 0);
inline void swap(int &x, int &y) {
int tmp = x;
x = y;
y = tmp;
}
RawFileIO::RawFileIO()
: knownSize(false), fileSize(0), fd(-1), oldfd(-1), canWrite(false) {}
RawFileIO::RawFileIO(const std::string &fileName)
: name(fileName),
knownSize(false),
fileSize(0),
fd(-1),
oldfd(-1),
canWrite(false) {}
RawFileIO::~RawFileIO() {
int _fd = -1;
int _oldfd = -1;
swap(_fd, fd);
swap(_oldfd, oldfd);
if (_oldfd != -1) close(_oldfd);
if (_fd != -1) close(_fd);
}
Interface RawFileIO::interface() const { return RawFileIO_iface; }
/*
Workaround for opening a file for write when permissions don't allow.
Since the kernel has already checked permissions, we can assume it is ok to
provide access. So force it by changing permissions temporarily. Should
be called with a lock around it so that there won't be a race condition
with calls to lstat picking up the wrong permissions.
*/
static int open_readonly_workaround(const char *path, int flags) {
int fd = -1;
struct stat stbuf;
memset(&stbuf, 0, sizeof(struct stat));
if (lstat(path, &stbuf) != -1) {
// make sure user has read/write permission..
chmod(path, stbuf.st_mode | 0600);
fd = ::open(path, flags);
chmod(path, stbuf.st_mode);
} else {
LOG(INFO) << "can't stat file " << path;
}
return fd;
}
/*
We shouldn't have to support all possible open flags, so untaint the flags
argument by only taking ones we understand and accept.
- Since the kernel has already done permission tests before calling us, we
shouldn't have to worry about access control.
- Basically we just need to distinguish between read and write flags
- Also keep the O_LARGEFILE flag, in case the underlying filesystem needs
it..
*/
int RawFileIO::open(int flags) {
bool requestWrite = ((flags & O_RDWR) || (flags & O_WRONLY));
VLOG(1) << "open call for " << (requestWrite ? "writable" : "read only")
<< " file";
int result = 0;
// if we have a descriptor and it is writable, or we don't need writable..
if ((fd >= 0) && (canWrite || !requestWrite)) {
VLOG(1) << "using existing file descriptor";
result = fd; // success
} else {
int finalFlags = requestWrite ? O_RDWR : O_RDONLY;
#if defined(O_LARGEFILE)
if (flags & O_LARGEFILE) finalFlags |= O_LARGEFILE;
#else
#warning O_LARGEFILE not supported
#endif
int newFd = ::open(name.c_str(), finalFlags);
VLOG(1) << "open file with flags " << finalFlags << ", result = " << newFd;
if ((newFd == -1) && (errno == EACCES)) {
VLOG(1) << "using readonly workaround for open";
newFd = open_readonly_workaround(name.c_str(), finalFlags);
}
if (newFd >= 0) {
if (oldfd >= 0) {
LOG(ERROR) << "leaking FD?: oldfd = " << oldfd << ", fd = " << fd
<< ", newfd = " << newFd;
}
// the old fd might still be in use, so just keep it around for
// now.
canWrite = requestWrite;
oldfd = fd;
result = fd = newFd;
} else {
result = -errno;
LOG(INFO) << "::open error: " << strerror(errno);
}
}
LOG_IF(INFO, result < 0) << "file " << name << " open failure: " << -result;
return result;
}
int RawFileIO::getAttr(struct stat *stbuf) const {
int res = lstat(name.c_str(), stbuf);
int eno = errno;
LOG_IF(INFO, res < 0) << "getAttr error on " << name << ": " << strerror(eno);
return (res < 0) ? -eno : 0;
}
void RawFileIO::setFileName(const char *fileName) { name = fileName; }
const char *RawFileIO::getFileName() const { return name.c_str(); }
off_t RawFileIO::getSize() const {
if (!knownSize) {
struct stat stbuf;
memset(&stbuf, 0, sizeof(struct stat));
int res = lstat(name.c_str(), &stbuf);
if (res == 0) {
fileSize = stbuf.st_size;
knownSize = true;
return fileSize;
} else
return -1;
} else {
return fileSize;
}
}
ssize_t RawFileIO::read(const IORequest &req) const {
rAssert(fd >= 0);
VLOG(2) << "Read " << req.dataLen << " bytes from offset " << req.offset;
ssize_t readSize = pread(fd, req.data, req.dataLen, req.offset);
if (readSize < 0) {
LOG(INFO) << "read failed at offset " << req.offset << " for "
<< req.dataLen << " bytes: " << strerror(errno);
}
return readSize;
}
bool RawFileIO::write(const IORequest &req) {
rAssert(fd >= 0);
rAssert(true == canWrite);
VLOG(2) << "Write " << req.dataLen << " bytes to offset " << req.offset;
int retrys = 10;
void *buf = req.data;
ssize_t bytes = req.dataLen;
off_t offset = req.offset;
while (bytes && retrys > 0) {
ssize_t writeSize = ::pwrite(fd, buf, bytes, offset);
if (writeSize < 0) {
knownSize = false;
LOG(INFO) << "write failed at offset " << offset << " for " << bytes
<< " bytes: " << strerror(errno);
return false;
}
bytes -= writeSize;
offset += writeSize;
buf = (void *)((char *)buf + writeSize);
--retrys;
}
if (bytes != 0) {
LOG(ERROR) << "Write error: wrote " << (req.dataLen - bytes) << " bytes of "
<< req.dataLen << ", max retries reached";
knownSize = false;
return false;
} else {
if (knownSize) {
off_t last = req.offset + req.dataLen;
if (last > fileSize) fileSize = last;
}
return true;
}
}
int RawFileIO::truncate(off_t size) {
int res;
if (fd >= 0 && canWrite) {
res = ::ftruncate(fd, size);
#ifndef __FreeBSD__
::fdatasync(fd);
#endif
} else
res = ::truncate(name.c_str(), size);
if (res < 0) {
int eno = errno;
LOG(INFO) << "truncate failed for " << name << " (" << fd << ") size "
<< size << ", error " << strerror(eno);
res = -eno;
knownSize = false;
} else {
res = 0;
fileSize = size;
knownSize = true;
}
return res;
}
bool RawFileIO::isWritable() const { return canWrite; }
} // namespace encfs
namespace encfs {
static Interface MemFileIO_iface = makeInterface("FileIO/Mem", 1, 0, 0);
MemFileIO::MemFileIO(int size) : writable(false) { buf.resize(size); }
MemFileIO::~MemFileIO() {}
Interface MemFileIO::interface() const { return MemFileIO_iface; }
void MemFileIO::setFileName(const char* name) { this->name = name; }
const char* MemFileIO::getFileName() const { return name.c_str(); }
int MemFileIO::open(int flags) {
bool requestWrite = ((flags & O_RDWR) || (flags & O_WRONLY));
writable = writable || requestWrite;
LOG(ERROR) << "returning fake file descriptor";
return 0;
}
int MemFileIO::getAttr(struct stat* stbuf) const {
stbuf->st_size = buf.size();
return 0;
}
off_t MemFileIO::getSize() const { return buf.size(); }
ssize_t MemFileIO::read(const IORequest& req) const {
rAssert(req.offset >= 0);
int len = req.dataLen;
if (req.offset + req.dataLen > getSize()) {
len = getSize() - req.offset;
}
if (len < 0) {
len = 0;
}
memcpy(req.data, &buf[req.offset], len);
return len;
}
bool MemFileIO::write(const IORequest& req) {
rAssert(req.offset >= 0);
if (req.offset + req.dataLen > getSize()) {
truncate(req.offset + req.dataLen);
}
rAssert(req.offset + req.dataLen <= getSize());
memcpy(&buf[req.offset], req.data, req.dataLen);
return true;
}
int MemFileIO::truncate(off_t size) {
buf.resize(size);
return 0;
}
bool MemFileIO::isWritable() const { return writable; }
} // namespace encfs
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "base/base64.h"
#include "cipher/Cipher.h"
#include "fs/NullNameIO.h"
#include <cstring>
static shared_ptr<NameIO> NewNNIO( const Interface &,
const shared_ptr<Cipher> &, const CipherKey & )
{
return shared_ptr<NameIO>( new NullNameIO() );
}
static Interface NNIOIface = makeInterface("nameio/null", 1, 0, 0);
static bool NullNameIO_registered = NameIO::Register("Null",
"No encryption of filenames", NNIOIface, NewNNIO, false);
NullNameIO::NullNameIO( )
{
}
NullNameIO::~NullNameIO()
{
}
Interface NullNameIO::interface() const
{
return NNIOIface;
}
