// Copyright (c) 2006-2013, Andrey N. Sabelnikov, www.sabelnikov.net
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of the Andrey N. Sabelnikov nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
#ifndef _LEVIN_BASE_H_
#define _LEVIN_BASE_H_
#include <cstdint>
#include "byte_stream.h"
#include "net_utils_base.h"
#include "span.h"
#define LEVIN_SIGNATURE 0x0101010101012101LL //Bender's nightmare
namespace epee
{
class byte_slice;
namespace levin
{
#pragma pack(push)
#pragma pack(1)
struct bucket_head
{
uint64_t m_signature;
uint64_t m_cb;
uint8_t m_have_to_return_data;
uint32_t m_command;
int32_t m_return_code;
uint32_t m_reservedA; //probably some flags in future
uint32_t m_reservedB; //probably some check sum in future
};
#pragma pack(pop)
#pragma pack(push)
#pragma pack(1)
struct bucket_head2
{
uint64_t m_signature;
uint64_t m_cb;
uint8_t m_have_to_return_data;
uint32_t m_command;
int32_t m_return_code;
uint32_t m_flags;
uint32_t m_protocol_version;
};
#pragma pack(pop)
#define LEVIN_DEFAULT_TIMEOUT_PRECONFIGURED 0
#define LEVIN_INITIAL_MAX_PACKET_SIZE 256*1024 // 256 KiB before handshake
#define LEVIN_DEFAULT_MAX_PACKET_SIZE 100000000 //100MB by default after handshake
#define LEVIN_PACKET_REQUEST 0x00000001
#define LEVIN_PACKET_RESPONSE 0x00000002
#define LEVIN_PACKET_BEGIN 0x00000004
#define LEVIN_PACKET_END 0x00000008
#define LEVIN_PROTOCOL_VER_0 0
#define LEVIN_PROTOCOL_VER_1 1
template<class t_connection_context = net_utils::connection_context_base>
struct levin_commands_handler
{
virtual int invoke(int command, const epee::span<const uint8_t> in_buff, byte_stream& buff_out, t_connection_context& context)=0;
virtual int notify(int command, const epee::span<const uint8_t> in_buff, t_connection_context& context)=0;
virtual void callback(t_connection_context& context){};
virtual void on_connection_new(t_connection_context& context){};
virtual void on_connection_close(t_connection_context& context){};
virtual ~levin_commands_handler(){}
};
#define LEVIN_OK 0
#define LEVIN_ERROR_CONNECTION -1
#define LEVIN_ERROR_CONNECTION_NOT_FOUND -2
#define LEVIN_ERROR_CONNECTION_DESTROYED -3
#define LEVIN_ERROR_CONNECTION_TIMEDOUT -4
#define LEVIN_ERROR_CONNECTION_NO_DUPLEX_PROTOCOL -5
#define LEVIN_ERROR_CONNECTION_HANDLER_NOT_DEFINED -6
#define LEVIN_ERROR_FORMAT -7
#define DESCRIBE_RET_CODE(code) case code: return #code;
inline
const char* get_err_descr(int err)
{
switch(err)
{
DESCRIBE_RET_CODE(LEVIN_OK);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION_NOT_FOUND);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION_DESTROYED);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION_TIMEDOUT);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION_NO_DUPLEX_PROTOCOL);
DESCRIBE_RET_CODE(LEVIN_ERROR_CONNECTION_HANDLER_NOT_DEFINED);
DESCRIBE_RET_CODE(LEVIN_ERROR_FORMAT);
default:
return "unknown code";
}
}
//! Provides space for levin (p2p) header, so that payload can be sent without copy
class message_writer
{
byte_slice finalize(uint32_t command, uint32_t flags, uint32_t return_code, bool expect_response);
public:
using header = bucket_head2;
explicit message_writer(std::size_t reserve = 8192);
message_writer(const message_writer&) = delete;
message_writer(message_writer&&) = default;
~message_writer() = default;
message_writer& operator=(const message_writer&) = delete;
message_writer& operator=(message_writer&&) = default;
//! \return Size of payload (excludes header size).
std::size_t payload_size() const noexcept
{
return buffer.size() < sizeof(header) ? 0 : buffer.size() - sizeof(header);
}
byte_slice finalize_invoke(uint32_t command) { return finalize(command, LEVIN_PACKET_REQUEST, 0, true); }
byte_slice finalize_notify(uint32_t command) { return finalize(command, LEVIN_PACKET_REQUEST, 0, false); }
byte_slice finalize_response(uint32_t command, uint32_t return_code)
{
return finalize(command, LEVIN_PACKET_RESPONSE, return_code, false);
}
//! Has space for levin header until a finalize method is used
byte_stream buffer;
};
//! \return Intialized levin header.
bucket_head2 make_header(uint32_t command, uint64_t msg_size, uint32_t flags, bool expect_response) noexcept;
/*! Generate a dummy levin message.
\param noise_bytes Total size of the returned `byte_slice`.
\return `nullptr` if `noise_size` is smaller than the levin header.
Otherwise, a dummy levin message. */
byte_slice make_noise_notify(std::size_t noise_bytes);
/*! Generate 1+ levin messages that are identical to the noise message size.
\param noise_size Each levin message will be identical to this value.
\return `nullptr` if `noise.size()` is less than the levin header size.
Otherwise, a levin notification message OR 2+ levin fragment messages.
Each message is `noise.size()` in length. */
byte_slice make_fragmented_notify(const std::size_t noise_size, int command, message_writer message);
}
}
#endif //_LEVIN_BASE_H_
