// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012-2017 OpenVPN Inc.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License Version 3
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program in the COPYING file.
// If not, see .
#ifndef OPENVPN_COMMON_PERSISTFILE_H
#define OPENVPN_COMMON_PERSISTFILE_H
#include // for open(), lseek(), ftruncate()
#include // for open()
#include // for open()
#include // for write(), lseek(), ftruncate()
#include
#include
#include
#include
#include
#include
#include
#include
namespace openvpn {
class PersistentFile
{
public:
PersistentFile(const std::string& fn_arg)
: fn(fn_arg)
{
const int f = ::open(fn.c_str(), O_WRONLY|O_CREAT|O_CLOEXEC, S_IRUSR|S_IWUSR);
if (f < 0)
syserr("open");
fd.reset(f);
}
void write(const void *buf, size_t count)
{
const off_t off = ::lseek(fd(), 0, SEEK_SET);
if (off < 0)
syserr("seek");
if (off)
err("unexpected seek");
if (::ftruncate(fd(), 0) < 0)
syserr("truncate");
const ssize_t len = write_retry(fd(), buf, count);
if (len < 0)
syserr("write");
if (len != count || len != ::lseek(fd(), 0, SEEK_CUR))
err("incomplete write");
if (::ftruncate(fd(), len) < 0)
syserr("truncate");
}
struct stat stat()
{
struct stat s;
if (::fstat(fd(), &s) < 0)
syserr("fstat");
return s;
}
void write(const Buffer& buf)
{
write(buf.c_data(), buf.size());
}
void write(const std::string& str)
{
write(str.c_str(), str.length());
}
private:
void syserr(const char *type)
{
const int eno = errno;
OPENVPN_THROW_EXCEPTION(fn << " : " << type << " error : " << strerror_str(eno));
}
void err(const char *type)
{
OPENVPN_THROW_EXCEPTION(fn << " : " << type << " error");
}
std::string fn;
ScopedFD fd;
};
}
#endif