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// 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- OpenVPN Inc.
//
// SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
#ifndef OPENVPN_BUFFER_BUFCOMPLETE_H
#define OPENVPN_BUFFER_BUFCOMPLETE_H
#include <cstdint> // for std::uint32_t, uint16_t, uint8_t
#include <algorithm> // for std::min
#include <openvpn/buffer/buffer.hpp>
namespace openvpn {
class BufferComplete
{
public:
virtual ~BufferComplete() = default;
/* each advance/get method returns false if message is incomplete */
bool advance(size_t size)
{
while (size)
{
if (!fetch_buffer())
return false;
const size_t s = std::min(size, buf.size());
buf.advance(s);
size -= s;
}
return true;
}
// assumes embedded big-endian uint16_t length in the stream
bool advance_string()
{
std::uint8_t h, l;
if (!get(h))
return false;
if (!get(l))
return false;
return advance(size_t(h) << 8 | size_t(l));
}
bool advance_to_null()
{
std::uint8_t c;
while (get(c))
{
if (!c)
return true;
}
return false;
}
bool get(std::uint8_t &c)
{
if (!fetch_buffer())
return false;
c = buf.pop_front();
return true;
}
bool defined() const
{
return buf.defined();
}
protected:
void reset_buf(const Buffer &buf_arg)
{
buf = buf_arg;
}
void reset_buf()
{
buf.reset_content();
}
private:
virtual void next_buffer() = 0;
bool fetch_buffer()
{
if (buf.defined())
return true;
next_buffer();
return buf.defined();
}
Buffer buf;
};
} // namespace openvpn
#endif
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