ProtocolMessage.h

//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.
 
    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#ifndef RIPPLE_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
#define RIPPLE_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
 
#include <ripple/basics/ByteUtilities.h>
#include <ripple/overlay/Compression.h>
#include <ripple/overlay/Message.h>
#include <ripple/overlay/impl/ZeroCopyStream.h>
#include <ripple/protocol/messages.h>
#include <boost/asio/buffer.hpp>
#include <boost/asio/buffers_iterator.hpp>
#include <boost/system/error_code.hpp>
#include <cassert>
#include <cstdint>
#include <memory>
#include <optional>
#include <type_traits>
#include <vector>
 
namespace ripple {
 
template <class = void>
std::string
protocolMessageName(int type)
{
    switch (type)
    {
        case protocol::mtMANIFESTS:
            return "manifests";
        case protocol::mtPING:
            return "ping";
        case protocol::mtCLUSTER:
            return "cluster";
        case protocol::mtGET_SHARD_INFO:
            return "get_shard_info";
        case protocol::mtSHARD_INFO:
            return "shard_info";
        case protocol::mtGET_PEER_SHARD_INFO:
            return "get_peer_shard_info";
        case protocol::mtPEER_SHARD_INFO:
            return "peer_shard_info";
        case protocol::mtENDPOINTS:
            return "endpoints";
        case protocol::mtTRANSACTION:
            return "tx";
        case protocol::mtGET_LEDGER:
            return "get_ledger";
        case protocol::mtLEDGER_DATA:
            return "ledger_data";
        case protocol::mtPROPOSE_LEDGER:
            return "propose";
        case protocol::mtSTATUS_CHANGE:
            return "status";
        case protocol::mtHAVE_SET:
            return "have_set";
        case protocol::mtVALIDATORLIST:
            return "validator_list";
        case protocol::mtVALIDATORLISTCOLLECTION:
            return "validator_list_collection";
        case protocol::mtVALIDATION:
            return "validation";
        case protocol::mtGET_OBJECTS:
            return "get_objects";
        case protocol::mtSQUELCH:
            return "squelch";
        default:
            break;
    }
    return "unknown";
}
 
namespace detail {
 
struct MessageHeader
{
    std::uint32_t total_wire_size = 0;
 
    std::uint32_t header_size = 0;
 
    std::uint32_t payload_wire_size = 0;
 
    std::uint32_t uncompressed_size = 0;
 
    std::uint16_t message_type = 0;
 
    compression::Algorithm algorithm = compression::Algorithm::None;
};
 
template <typename BufferSequence>
auto
buffersBegin(BufferSequence const& bufs)
{
    return boost::asio::buffers_iterator<BufferSequence, std::uint8_t>::begin(
        bufs);
}
 
template <typename BufferSequence>
auto
buffersEnd(BufferSequence const& bufs)
{
    return boost::asio::buffers_iterator<BufferSequence, std::uint8_t>::end(
        bufs);
}
 
template <class BufferSequence>
std::optional<MessageHeader>
parseMessageHeader(
    boost::system::error_code& ec,
    BufferSequence const& bufs,
    std::size_t size)
{
    using namespace ripple::compression;
 
    MessageHeader hdr;
    auto iter = buffersBegin(bufs);
    assert(iter != buffersEnd(bufs));
 
    // Check valid header compressed message:
    // - 4 bits are the compression algorithm, 1st bit is always set to 1
    // - 2 bits are always set to 0
    // - 26 bits are the payload size
    // - 32 bits are the uncompressed data size
    if (*iter & 0x80)
    {
        hdr.header_size = headerBytesCompressed;
 
        // not enough bytes to parse the header
        if (size < hdr.header_size)
        {
            ec = make_error_code(boost::system::errc::success);
            return std::nullopt;
        }
 
        if (*iter & 0x0C)
        {
            ec = make_error_code(boost::system::errc::protocol_error);
            return std::nullopt;
        }
 
        hdr.algorithm = static_cast<compression::Algorithm>(*iter & 0xF0);
 
        if (hdr.algorithm != compression::Algorithm::LZ4)
        {
            ec = make_error_code(boost::system::errc::protocol_error);
            return std::nullopt;
        }
 
        for (int i = 0; i != 4; ++i)
            hdr.payload_wire_size = (hdr.payload_wire_size << 8) + *iter++;
 
        // clear the top four bits (the compression bits).
        hdr.payload_wire_size &= 0x0FFFFFFF;
 
        hdr.total_wire_size = hdr.header_size + hdr.payload_wire_size;
 
        for (int i = 0; i != 2; ++i)
            hdr.message_type = (hdr.message_type << 8) + *iter++;
 
        for (int i = 0; i != 4; ++i)
            hdr.uncompressed_size = (hdr.uncompressed_size << 8) + *iter++;
 
        return hdr;
    }
 
    // Check valid header uncompressed message:
    // - 6 bits are set to 0
    // - 26 bits are the payload size
    if ((*iter & 0xFC) == 0)
    {
        hdr.header_size = headerBytes;
 
        if (size < hdr.header_size)
        {
            ec = make_error_code(boost::system::errc::success);
            return std::nullopt;
        }
 
        hdr.algorithm = Algorithm::None;
 
        for (int i = 0; i != 4; ++i)
            hdr.payload_wire_size = (hdr.payload_wire_size << 8) + *iter++;
 
        hdr.uncompressed_size = hdr.payload_wire_size;
        hdr.total_wire_size = hdr.header_size + hdr.payload_wire_size;
 
        for (int i = 0; i != 2; ++i)
            hdr.message_type = (hdr.message_type << 8) + *iter++;
 
        return hdr;
    }
 
    ec = make_error_code(boost::system::errc::no_message);
    return std::nullopt;
}
 
template <
    class T,
    class Buffers,
    class = std::enable_if_t<
        std::is_base_of<::google::protobuf::Message, T>::value>>
std::shared_ptr<T>
parseMessageContent(MessageHeader const& header, Buffers const& buffers)
{
    auto const m = std::make_shared<T>();
 
    ZeroCopyInputStream<Buffers> stream(buffers);
    stream.Skip(header.header_size);
 
    if (header.algorithm != compression::Algorithm::None)
    {
        std::vector<std::uint8_t> payload;
        payload.resize(header.uncompressed_size);
 
        auto const payloadSize = ripple::compression::decompress(
            stream,
            header.payload_wire_size,
            payload.data(),
            header.uncompressed_size,
            header.algorithm);
 
        if (payloadSize == 0 || !m->ParseFromArray(payload.data(), payloadSize))
            return {};
    }
    else if (!m->ParseFromZeroCopyStream(&stream))
        return {};
 
    return m;
}
 
template <
    class T,
    class Buffers,
    class Handler,
    class = std::enable_if_t<
        std::is_base_of<::google::protobuf::Message, T>::value>>
bool
invoke(MessageHeader const& header, Buffers const& buffers, Handler& handler)
{
    auto const m = parseMessageContent<T>(header, buffers);
    if (!m)
        return false;
 
    using namespace ripple::compression;
    handler.onMessageBegin(
        header.message_type,
        m,
        header.payload_wire_size,
        header.uncompressed_size,
        header.algorithm != Algorithm::None);
    handler.onMessage(m);
    handler.onMessageEnd(header.message_type, m);
 
    return true;
}
 
}  // namespace detail
 
template <class Buffers, class Handler>
std::pair<std::size_t, boost::system::error_code>
invokeProtocolMessage(
    Buffers const& buffers,
    Handler& handler,
    std::size_t& hint)
{
    std::pair<std::size_t, boost::system::error_code> result = {0, {}};
 
    auto const size = boost::asio::buffer_size(buffers);
 
    if (size == 0)
        return result;
 
    auto header = detail::parseMessageHeader(result.second, buffers, size);
 
    // If we can't parse the header then it may be that we don't have enough
    // bytes yet, or because the message was cut off (if error_code is success).
    // Otherwise we failed to match the header's marker (error_code is set to
    // no_message) or the compression algorithm is invalid (error_code is
    // protocol_error) and signal an error.
    if (!header)
        return result;
 
    // We implement a maximum size for protocol messages. Sending a message
    // whose size exceeds this may result in the connection being dropped. A
    // larger message size may be supported in the future or negotiated as
    // part of a protocol upgrade.
    if (header->payload_wire_size > maximiumMessageSize ||
        header->uncompressed_size > maximiumMessageSize)
    {
        result.second = make_error_code(boost::system::errc::message_size);
        return result;
    }
 
    // We requested uncompressed messages from the peer but received compressed.
    if (!handler.compressionEnabled() &&
        header->algorithm != compression::Algorithm::None)
    {
        result.second = make_error_code(boost::system::errc::protocol_error);
        return result;
    }
 
    // We don't have the whole message yet. This isn't an error but we have
    // nothing to do.
    if (header->total_wire_size > size)
    {
        hint = header->total_wire_size - size;
        return result;
    }
 
    bool success;
 
    switch (header->message_type)
    {
        case protocol::mtMANIFESTS:
            success = detail::invoke<protocol::TMManifests>(
                *header, buffers, handler);
            break;
        case protocol::mtPING:
            success =
                detail::invoke<protocol::TMPing>(*header, buffers, handler);
            break;
        case protocol::mtCLUSTER:
            success =
                detail::invoke<protocol::TMCluster>(*header, buffers, handler);
            break;
        case protocol::mtGET_SHARD_INFO:
            success = detail::invoke<protocol::TMGetShardInfo>(
                *header, buffers, handler);
            break;
        case protocol::mtSHARD_INFO:
            success = detail::invoke<protocol::TMShardInfo>(
                *header, buffers, handler);
            break;
        case protocol::mtGET_PEER_SHARD_INFO:
            success = detail::invoke<protocol::TMGetPeerShardInfo>(
                *header, buffers, handler);
            break;
        case protocol::mtPEER_SHARD_INFO:
            success = detail::invoke<protocol::TMPeerShardInfo>(
                *header, buffers, handler);
            break;
        case protocol::mtENDPOINTS:
            success = detail::invoke<protocol::TMEndpoints>(
                *header, buffers, handler);
            break;
        case protocol::mtTRANSACTION:
            success = detail::invoke<protocol::TMTransaction>(
                *header, buffers, handler);
            break;
        case protocol::mtGET_LEDGER:
            success = detail::invoke<protocol::TMGetLedger>(
                *header, buffers, handler);
            break;
        case protocol::mtLEDGER_DATA:
            success = detail::invoke<protocol::TMLedgerData>(
                *header, buffers, handler);
            break;
        case protocol::mtPROPOSE_LEDGER:
            success = detail::invoke<protocol::TMProposeSet>(
                *header, buffers, handler);
            break;
        case protocol::mtSTATUS_CHANGE:
            success = detail::invoke<protocol::TMStatusChange>(
                *header, buffers, handler);
            break;
        case protocol::mtHAVE_SET:
            success = detail::invoke<protocol::TMHaveTransactionSet>(
                *header, buffers, handler);
            break;
        case protocol::mtVALIDATION:
            success = detail::invoke<protocol::TMValidation>(
                *header, buffers, handler);
            break;
        case protocol::mtVALIDATORLIST:
            success = detail::invoke<protocol::TMValidatorList>(
                *header, buffers, handler);
            break;
        case protocol::mtVALIDATORLISTCOLLECTION:
            success = detail::invoke<protocol::TMValidatorListCollection>(
                *header, buffers, handler);
            break;
        case protocol::mtGET_OBJECTS:
            success = detail::invoke<protocol::TMGetObjectByHash>(
                *header, buffers, handler);
            break;
        case protocol::mtSQUELCH:
            success =
                detail::invoke<protocol::TMSquelch>(*header, buffers, handler);
            break;
        default:
            handler.onMessageUnknown(header->message_type);
            success = true;
            break;
    }
 
    result.first = header->total_wire_size;
 
    if (!success)
        result.second = make_error_code(boost::system::errc::bad_message);
 
    return result;
}
 
}  // namespace ripple
 
#endif