void responder::send_pool_tx(const code& ec, const transaction& tx,
const hash_digest& tx_hash, channel::ptr node)
{
if (ec == error::service_stopped)
return;
if (ec == error::not_found)
{
log::debug(LOG_RESPONDER)
<< "Transaction for [" << node->authority()
<< "] not in mempool [" << encode_hash(tx_hash) << "]";
// It wasn't in the mempool, so relay the request to the blockchain.
blockchain_.fetch_transaction(tx_hash,
std::bind(&responder::send_chain_tx,
this, _1, _2, tx_hash, node));
return;
}
if (ec)
{
log::error(LOG_RESPONDER)
<< "Failure fetching mempool tx data for ["
<< node->authority() << "] " << ec.message();
node->stop(ec);
return;
}
send_tx(tx, tx_hash, node);
}
void session::handle_is_pending(bool pending, channel::ptr channel,
result_handler handle_started)
{
if (pending)
{
log::debug(LOG_NETWORK)
<< "Rejected connection from [" << channel->authority()
<< "] as loopback.";
handle_started(error::accept_failed);
return;
}
const auto version = channel->version();
if (version.value < bc::peer_minimum_version)
{
log::debug(LOG_NETWORK)
<< "Peer version (" << version.value << ") below minimum ("
<< bc::peer_minimum_version << ") ["
<< channel->authority() << "]";
handle_started(error::accept_failed);
return;
}
network_.store(channel, handle_started);
}
// protected:
void session::register_channel(channel::ptr channel,
result_handler handle_started, result_handler handle_stopped)
{
result_handler stop_handler =
BIND_3(do_remove, _1, channel, handle_stopped);
result_handler start_handler =
BIND_4(handle_start, _1, channel, handle_started, stop_handler);
if (stopped())
{
start_handler(error::service_stopped);
return;
}
if (incoming_)
{
handle_pend(error::success, channel, start_handler);
return;
}
channel->set_notify(notify_);
channel->set_nonce(nonzero_pseudo_random());
result_handler unpend_handler =
BIND_3(do_unpend, _1, channel, start_handler);
pending_.store(channel,
BIND_3(handle_pend, _1, channel, unpend_handler));
}
// en.bitcoin.it/wiki/Protocol_documentation#getdata
// getdata can be used to retrieve transactions, but only if they are
// in the memory pool or relay set - arbitrary access to transactions
// in the chain is not allowed to avoid having clients start to depend
// on nodes having full transaction indexes (which modern nodes do not).
void responder::send_chain_tx(const code& ec, const transaction& tx,
const hash_digest& tx_hash, channel::ptr node)
{
if (ec == error::service_stopped)
return;
if (ec == error::not_found)
{
log::debug(LOG_RESPONDER)
<< "Transaction for [" << node->authority()
<< "] not in blockchain [" << encode_hash(tx_hash) << "]";
// It wasn't in the blockchain, so send notfound.
send_tx_not_found(tx_hash, node);
return;
}
if (ec)
{
log::error(LOG_RESPONDER)
<< "Failure fetching blockchain tx data for ["
<< node->authority() << "] " << ec.message();
node->stop(ec);
return;
}
send_tx(tx, tx_hash, node);
}
// We don't seem to be getting getdata requests.
void responder::receive_get_data(const code& ec, const get_data& packet,
channel::ptr node)
{
if (ec == error::channel_stopped)
return;
const auto peer = node->authority();
if (ec)
{
log::debug(LOG_RESPONDER)
<< "Failure in receive get data [" << peer << "] " << ec.message();
node->stop(ec);
return;
}
// Resubscribe to serve tx and blocks.
node->subscribe<message::get_data>(
std::bind(&responder::receive_get_data,
this, _1, _2, node));
log::debug(LOG_RESPONDER)
<< "Getdata BEGIN [" << peer << "] "
<< "txs (" << packet.count(inventory_type_id::transaction) << ") "
<< "blocks (" << packet.count(inventory_type_id::block) << ") "
<< "bloom (" << packet.count(inventory_type_id::filtered_block) << ")";
for (const auto& inventory: packet.inventories)
{
switch (inventory.type)
{
case inventory_type_id::transaction:
log::debug(LOG_RESPONDER)
<< "Transaction getdata for [" << peer << "] "
<< encode_hash(inventory.hash);
tx_pool_.fetch(inventory.hash,
std::bind(&responder::send_pool_tx,
this, _1, _2, inventory.hash, node));
break;
case inventory_type_id::block:
log::debug(LOG_RESPONDER)
<< "Block getdata for [" << peer << "] "
<< encode_hash(inventory.hash);
block_fetcher::fetch(blockchain_, inventory.hash,
std::bind(&responder::send_block,
this, _1, _2, inventory.hash, node));
break;
case inventory_type_id::error:
case inventory_type_id::none:
default:
log::debug(LOG_RESPONDER)
<< "Ignoring invalid getdata type for [" << peer << "]";
}
}
log::debug(LOG_RESPONDER)
<< "Getdata END [" << peer << "]";
}
void session_inbound::handle_accept(const code& ec, channel::ptr channel,
acceptor::ptr accept)
{
if (stopped())
return;
start_accept(error::success, accept);
if (ec)
{
log::debug(LOG_NETWORK)
<< "Failure accepting connection: " << ec.message();
return;
}
if (blacklisted(channel->authority()))
{
log::debug(LOG_NETWORK)
<< "Rejected inbound connection from ["
<< channel->authority() << "] due to blacklisted address.";
return;
}
connection_count(
dispatch_.ordered_delegate(&session_inbound::handle_connection_count,
shared_from_base<session_inbound>(), _1, channel));
}
void session_inbound::handle_accept(const code& ec, channel::ptr channel,
acceptor::ptr accept)
{
if (stopped())
{
log::debug(LOG_NETWORK)
<< "Suspended inbound connection.";
return;
}
start_accept(error::success, accept);
if (ec)
{
log::debug(LOG_NETWORK)
<< "Failure accepting connection: " << ec.message();
return;
}
if (blacklisted(channel->authority()))
{
log::debug(LOG_NETWORK)
<< "Rejected inbound connection from ["
<< channel->authority() << "] due to blacklisted address.";
return;
}
connection_count(BIND2(handle_connection_count, _1, channel));
}
// protected:
void session::start_channel(channel::ptr channel,
result_handler handle_started)
{
channel->set_notify(notify_on_connect_);
channel->set_nonce(pseudo_random(1, max_uint64));
// The channel starts, invokes the handler, then starts the read cycle.
channel->start(
BIND_3(handle_starting, _1, channel, handle_started));
}
void session::handle_start(const code& ec, channel::ptr channel,
result_handler handle_started, result_handler handle_stopped)
{
// Must either stop or subscribe the channel for stop before returning.
if (ec)
channel->stop(ec);
else
channel->subscribe_stop(handle_stopped);
// This is the end of the registration sequence.
handle_started(ec);
}
void protocol::handle_accept(const code& ec, channel::ptr node,
acceptor::ptr accept)
{
// Relisten for connections.
start_accept(ec, accept);
if (ec)
{
log_debug(LOG_PROTOCOL)
<< "Failure accepting connection: " << ec.message();
return;
}
if (inbound_connections_.size() >= max_inbound_)
{
log_debug(LOG_PROTOCOL)
<< "Rejected inbound connection due to connection limit";
return;
}
const auto address = node->address();
if (is_blacklisted(node->address()))
{
log_debug(LOG_PROTOCOL)
<< "Rejected inbound connection due to blacklisted address";
return;
}
if (is_loopback(node))
{
log_debug(LOG_PROTOCOL)
<< "Rejected inbound connection from self";
return;
}
// Save the connection as we are now assured of getting stop event.
inbound_connections_.push_back(node);
// Accepted!
log_info(LOG_PROTOCOL)
<< "Accepted connection from [" << address << "] ("
<< inbound_connections_.size() << " total)";
const auto stop_handler =
dispatch_.ordered_delegate(&protocol::inbound_channel_stopped,
this, _1, node, address.to_string());
start_talking(node, stop_handler, relay_);
}
void session_manual::handle_connect(const code& ec, channel::ptr channel,
const std::string& hostname, uint16_t port, uint32_t remaining,
connector::ptr connector, channel_handler handler)
{
unpend(connector);
if (ec)
{
LOG_WARNING(LOG_NETWORK)
<< "Failure connecting [" << config::endpoint(hostname, port)
<< "] manually: " << ec.message();
// Retry logic.
// The handler invoke is the failure end of the connect sequence.
if (settings_.manual_attempt_limit == 0)
start_connect(hostname, port, 0, handler);
else if (remaining > 0)
start_connect(hostname, port, remaining - 1, handler);
else
handler(ec, nullptr);
return;
}
LOG_INFO(LOG_NETWORK)
<< "Connected manual channel [" << config::endpoint(hostname, port)
<< "] as [" << channel->authority() << "]";
register_channel(channel,
BIND5(handle_channel_start, _1, hostname, port, channel, handler),
BIND3(handle_channel_stop, _1, hostname, port));
}
void protocol::handle_handshake(const code& ec, channel::ptr node)
{
if (ec)
{
log_debug(LOG_PROTOCOL) << "Failure in peer handshake ["
<< node->address() << "] " << ec.message();
node->stop(ec);
return;
}
// Attach ping protocol to the new connection (until node stop event).
std::make_shared<protocol_ping>(node, pool_, timeouts_.heartbeat)->start();
// Attach address protocol to the new connection (until node stop event).
std::make_shared<protocol_address>(node, pool_, hosts_, self_)->start();
}
bool pending_channels::safe_store(channel::ptr channel)
{
const auto version_nonce = channel->nonce();
const auto match = [version_nonce](const channel::ptr& entry)
{
return entry->nonce() == version_nonce;
};
// Critical Section
///////////////////////////////////////////////////////////////////////////
mutex_.lock_upgrade();
const auto it = std::find_if(channels_.begin(), channels_.end(), match);
const auto found = it != channels_.end();
if (!found)
{
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mutex_.unlock_upgrade_and_lock();
channels_.push_back(channel);
mutex_.unlock();
//---------------------------------------------------------------------
return true;
}
mutex_.unlock_upgrade();
///////////////////////////////////////////////////////////////////////////
return false;
}
void session::do_unpend(const code& ec, channel::ptr channel,
result_handler handle_started)
{
channel->set_nonce(0);
pending_.remove(channel, BIND_1(handle_unpend, _1));
handle_started(ec);
}
void session::handle_remove(const code& ec, channel::ptr channel)
{
if (ec)
LOG_DEBUG(LOG_NETWORK)
<< "Failed to remove channel [" << channel->authority() << "] "
<< ec.message();
}
code p2p::store(channel::ptr channel)
{
const auto address = channel->authority();
const auto match = [&address](const channel::ptr& element)
{
return element->authority() == address;
};
// May return error::address_in_use.
const auto ec = pending_close_.store(channel, match);
if (!ec && channel->notify())
channel_subscriber_->relay(error::success, channel);
return ec;
}
void session_manual::handle_connect(const code& ec, channel::ptr channel,
const std::string& hostname, uint16_t port, channel_handler handler,
uint16_t retries)
{
if (ec)
{
log::warning(LOG_NETWORK)
<< "Failure connecting [" << config::endpoint(hostname, port)
<< "] manually: " << ec.message();
// Retry logic.
if (settings_.connect_attempts == 0)
start_connect(hostname, port, handler, 0);
else if (retries > 0)
start_connect(hostname, port, handler, retries - 1);
else
handler(ec, nullptr);
return;
}
log::info(LOG_NETWORK)
<< "Connected manual channel [" << config::endpoint(hostname, port)
<< "] as [" << channel->authority() << "]";
register_channel(channel,
std::bind(&session_manual::handle_channel_start,
shared_from_base<session_manual>(), _1, hostname, port, channel, handler),
std::bind(&session_manual::handle_channel_stop,
shared_from_base<session_manual>(), _1, hostname, port));
}
void responder::send_tx_not_found(const hash_digest& hash, channel::ptr node)
{
const auto send_handler = [hash, node](const code& ec)
{
if (ec)
log::debug(LOG_RESPONDER)
<< "Failure sending tx notfound for ["
<< node->authority() << "]";
else
log::debug(LOG_RESPONDER)
<< "Sent tx notfound for [" << node->authority()
<< "] " << encode_hash(hash);
};
send_inventory_not_found(inventory_type_id::transaction, hash, node,
send_handler);
}
void responder::send_tx(const transaction& tx, const hash_digest& hash,
channel::ptr node)
{
const auto send_handler = [hash, node](const code& ec)
{
if (ec)
log::debug(LOG_RESPONDER)
<< "Failure sending tx for ["
<< node->authority() << "]";
else
log::debug(LOG_RESPONDER)
<< "Sent tx for [" << node->authority()
<< "] " << encode_hash(hash);
};
node->send(tx, send_handler);
}
void session_manual::attach_protocols(channel::ptr channel)
{
if (channel->negotiated_version() >= message::version::level::bip31)
attach<protocol_ping_60001>(channel)->start();
else
attach<protocol_ping_31402>(channel)->start();
attach<protocol_address_31402>(channel)->start();
}
void p2p::handle_new_connection(const code& ec, channel::ptr channel,
result_handler handler)
{
// Connection-in-use indicated here by error::address_in_use.
handler(ec);
if (!ec && channel->notify())
channel_subscriber_->relay(error::success, channel);
}
void session_outbound::handle_channel_stop(const code& ec,
connector::ptr connect, channel::ptr channel)
{
log::debug(LOG_NETWORK)
<< "Outbound channel stopped [" << channel->authority() << "] "
<< ec.message();
new_connection(connect);
}
void responder::send_block_not_found(const hash_digest& block_hash,
channel::ptr node)
{
const auto send_handler = [block_hash, node](const code& ec)
{
if (ec)
log::debug(LOG_RESPONDER)
<< "Failure sending block notfound for ["
<< node->authority() << "]";
else
log::debug(LOG_RESPONDER)
<< "Sent block notfound for [" << node->authority()
<< "] " << encode_hash(block_hash);
};
send_inventory_not_found(inventory_type_id::block, block_hash,
node, send_handler);
}
// protected:
void session::attach_handshake_protocols(channel::ptr channel,
result_handler handle_started)
{
// The negotiated_version is initialized to the configured maximum.
if (channel->negotiated_version() >= message::version::level::bip61)
attach<protocol_version_70002>(channel)->start(handle_started);
else
attach<protocol_version_31402>(channel)->start(handle_started);
}
void session::handle_start(const code& ec, channel::ptr channel,
result_handler handle_started, result_handler handle_stopped)
{
// Must either stop or subscribe the channel for stop before returning.
// All closures must eventually be invoked as otherwise it is a leak.
// Therefore upon start failure expect start failure and stop callbacks.
if (ec)
{
channel->stop(ec);
handle_stopped(ec);
}
else
{
channel->subscribe_stop(
BIND_3(do_remove, _1, channel, handle_stopped));
}
// This is the end of the registration sequence.
handle_started(ec);
}
void session_inbound::handle_connection_count(size_t connections,
channel::ptr channel)
{
if (connections >= settings_.inbound_connection_limit)
{
log::debug(LOG_NETWORK)
<< "Rejected inbound connection from ["
<< channel->authority() << "] due to connection limit.";
return;
}
log::info(LOG_NETWORK)
<< "Connected inbound channel [" << channel->authority() << "]";
register_channel(channel,
std::bind(&session_inbound::handle_channel_start,
shared_from_base<session_inbound>(), _1, channel),
std::bind(&session_inbound::handle_channel_stop,
shared_from_base<session_inbound>(), _1));
}
void responder::send_inventory_not_found(inventory_type_id type_id,
const hash_digest& hash, channel::ptr node, proxy::result_handler handler)
{
const inventory_vector block_inventory
{
type_id,
hash
};
const not_found lost{ { block_inventory } };
node->send(lost, handler);
}
void session::handle_handshake(const code& ec, channel::ptr channel,
result_handler handle_started)
{
if (ec)
{
log::debug(LOG_NETWORK)
<< "Failure in handshake with [" << channel->authority()
<< "] " << ec.message();
handle_started(ec);
return;
}
truth_handler handler =
BIND_3(handle_is_pending, _1, channel, handle_started);
// The loopback test is for incoming channels only.
if (incoming_)
pending_.exists(channel->version().nonce, handler);
else
handler(false);
}
bool protocol::is_loopback(channel::ptr node) const
{
const auto& outbound = outbound_connections_;
const auto id = node->identifier();
const auto found = [node, id](const channel::ptr& entry)
{
return (entry != node) && (entry->identifier() == id);
};
auto it = std::find_if(outbound.begin(), outbound.end(), found);
return it != outbound.end();
return true;
}
void session_inbound::handle_connection_count(size_t connections,
channel::ptr channel)
{
const auto connection_limit = settings_.inbound_connections +
settings_.outbound_connections;
if (connections >= connection_limit)
{
log::debug(LOG_NETWORK)
<< "Rejected inbound connection from ["
<< channel->authority() << "] due to connection limit.";
return;
}
log::info(LOG_NETWORK)
<< "Connected inbound channel [" << channel->authority() << "]";
register_channel(channel,
BIND2(handle_channel_start, _1, channel),
BIND1(handle_channel_stop, _1));
}
