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Peer.cpp
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Peer.cpp
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/*
* Dynamic Link Exchange Protocol (DLEP)
*
* Copyright (C) 2013, 2015, 2016, 2018, 2019 Massachusetts Institute of Technology
*/
/// @file
/// The Peer class implements the DLEP protocol starting after the peers
/// have a TCP connection established.
#include "Peer.h"
#include "NetUtils.h"
#include "DestAdvert.h"
#include <time.h>
#include <ctype.h>
using namespace std;
using namespace LLDLEP;
using namespace LLDLEP::internal;
Peer::Peer(boost::asio::ip::tcp::socket * peer_socket, DlepPtr dlep) :
dlep(dlep),
peer_type(string("unknown")),
pstate(PeerState::connected),
session_socket_(peer_socket),
peer_heartbeat_interval(0),
peer_heartbeat_interval_sec(0),
heartbeat_timer(dlep->io_service_),
heartbeat_msg(new ProtocolMessage(dlep->protocfg, dlep->logger)),
acktivity_timer(dlep->io_service_),
last_receive_time(std::time(nullptr)),
signal_recv_buffer{0},
signal_recv_len(0),
logger(dlep->logger)
{
ostringstream msg;
peer_endpoint_tcp = peer_socket->remote_endpoint();
peer_id = dlep->get_peer_id_from_endpoint(peer_endpoint_tcp);
LLDLEP::DataItems empty_data_items;
peer_pdp = dlep->info_base_manager->addPeer(peer_id, empty_data_items);
msg << "Peer ID is " << peer_id ;
LOG(DLEP_LOG_DEBUG, msg);
}
Peer::~Peer()
{
ostringstream msg;
msg << "peer=" << peer_id;
LOG(DLEP_LOG_DEBUG, msg);
delete session_socket_;
}
void
Peer::handle_send(const boost::system::error_code & error)
{
ostringstream msg ;
boost::recursive_mutex::scoped_lock lock(dlep->mutex);
msg << "peer=" << peer_id << " error=" << error;
LOG(DLEP_LOG_INFO, msg);
}
void
Peer::send_session_message(const uint8_t * packet, int size)
{
ostringstream msg;
msg << "to peer=" << peer_id << " size=" << size;
LOG(DLEP_LOG_INFO, msg);
boost::asio::async_write(*session_socket_,
boost::asio::buffer(packet, size),
boost::bind(&Peer::handle_send,
shared_from_this(),
boost::asio::placeholders::error));
}
//-----------------------------------------------------------------------------
// Response (ACK) sending and receiving
ResponsePending::ResponsePending(const ProtocolConfig * protocfg,
const ProtocolMessage & pm) :
queued(false),
send_time(0),
send_tries(0)
{
// Get the signal id of the expected response
ProtocolConfig::SignalInfo siginfo =
protocfg->get_signal_info(pm.get_signal_name());
response_id = siginfo.response_id;
assert(response_id != 0);
if (pm.is_signal())
{
response_name = protocfg->get_signal_name(response_id);
}
else
{
response_name = protocfg->get_message_name(response_id);
}
// Copy the serialized message to msg_buffer
std::size_t pm_length = pm.get_length();
msg_buffer = DlepMessageBuffer {new std::vector<std::uint8_t>(pm_length)};
memcpy(msg_buffer->data(), pm.get_buffer(), pm_length);
// If the protocol message contains a mac address, use it as the
// destination. Otherwise leave destination at its default value
// to indicate that this is a session-level message.
try
{
destination = pm.get_mac();
}
catch (const ProtocolMessage::DataItemNotPresent &)
{
/* no-op */
}
}
std::string
ResponsePending::queue_name() const
{
if (destination.mac_addr.empty())
{
return "session queue";
}
else
{
return "destination queue=" + destination.to_string();
}
}
bool
Peer::should_send_response(const std::string & response_name) const
{
ostringstream msg;
unsigned int random_percent = std::rand() % 100;
unsigned int ack_probability;
dlep->dlep_client.get_config_parameter("ack-probability",
&ack_probability);
bool sendit = (random_percent < ack_probability);
if (! sendit)
{
msg << "suppressing " << response_name << " to peer=" << peer_id;
LOG(DLEP_LOG_INFO, msg);
}
return sendit;
}
void
Peer::send_simple_response(const std::string & response_name,
const std::string & status_name,
const std::string & status_message,
const DlepMac * mac)
{
if (! should_send_response(response_name))
{
return;
}
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(response_name);
if (status_name != "")
{
pm.add_status(status_name, status_message);
}
if (mac != nullptr)
{
pm.add_mac(*mac);
}
// A freshly built message should be parsable.
std::string err = pm.parse_and_validate(dlep->is_modem(), __func__);
assert(err == "");
send_session_message(pm.get_buffer(), pm.get_length());
}
bool
Peer::is_not_interested(const DlepMac & destination) const
{
return (not_interested_destinations.find(destination) !=
not_interested_destinations.end() );
}
void
Peer::not_interested(const DlepMac & destination)
{
ostringstream msg;
msg << "peer=" << peer_id
<< " is not interested in destination=" << destination;
LOG(DLEP_LOG_INFO, msg);
(void)not_interested_destinations.insert(destination);
}
void
Peer::send_message_expecting_response(ResponsePendingPtr rp)
{
ostringstream msg;
msg << " to peer " << peer_id << " expecting " << rp->response_name
<< " " << rp->queue_name();
LOG(DLEP_LOG_INFO, msg);
if (is_not_interested(rp->destination))
{
msg << "not sending signal/message expecting " << rp->response_name
<< " because peer is not interested in destination="
<< rp->destination;
LOG(DLEP_LOG_INFO, msg);
return;
}
// If this message is not on the appropriate queue, add it.
if (! rp->queued)
{
// Get the queue for this destination, creating it if it
// wasn't there.
auto & dest_queue = responses_pending[rp->destination];
// Add the pending response to the queue for this destination.
dest_queue.push(rp);
rp->queued = true;
msg << rp->queue_name() << " size=" << dest_queue.size()
<< " queues now active=" << responses_pending.size();
LOG(DLEP_LOG_DEBUG, msg);
}
// if rp is at the head of its queue, send it
if (responses_pending[rp->destination].front() == rp)
{
int plen = rp->msg_buffer->size();
uint8_t * pptr = rp->msg_buffer->data();
send_session_message(pptr, plen);
rp->send_time = std::time(nullptr);
rp->send_tries++;
msg << "expecting " << rp->response_name
<< " from peer=" << peer_id
<< " tries=" << rp->send_tries;
LOG(DLEP_LOG_DEBUG, msg);
}
}
bool
Peer::handle_response(const ProtocolMessage & pm)
{
ostringstream msg;
const std::string received_response_name = pm.get_signal_name();
bool response_ok = false;
msg << "from peer=" << peer_id << " " << received_response_name;
// Extract destination from the response if there is one.
DlepMac destination;
try
{
destination = pm.get_mac();
msg << " destination=" << destination.to_string();
}
catch (const ProtocolMessage::DataItemNotPresent &)
{
/* no-op */
}
LOG(DLEP_LOG_INFO, msg);
try
{
std::queue<ResponsePendingPtr> & dest_queue =
responses_pending.at(destination);
ResponsePendingPtr expected_response = dest_queue.front();
std::string queue_name = expected_response->queue_name();
if (expected_response->response_id == pm.get_signal_id())
{
dest_queue.pop();
response_ok = true;
msg << "got expected " << queue_name << " response "
<< received_response_name;
LOG(DLEP_LOG_INFO, msg);
msg << queue_name << " size=" << dest_queue.size();
// If this queue is empty, remove it from the map.
// Otherwise, send the next message on the queue.
if (dest_queue.empty())
{
responses_pending.erase(destination);
}
else
{
send_message_expecting_response(dest_queue.front());
}
msg << " queues now active=" << responses_pending.size();
LOG(DLEP_LOG_DEBUG, msg);
}
else
{
msg << queue_name << " response mismatch: expected "
<< expected_response->response_name
<< " got " << received_response_name;
LOG(DLEP_LOG_ERROR, msg);
}
}
catch (const std::exception &)
{
// We come here if there was no queue in the map for the
// destination, or if the queue was empty. We don't
// need to do anything because response_ok will still
// be false.
}
if (! response_ok)
{
msg << "unexpected " << received_response_name;
LOG(DLEP_LOG_ERROR, msg);
terminate(ProtocolStrings::Unexpected_Message,
received_response_name);
}
return response_ok;
}
void
Peer::schedule_acktivity_timer()
{
// This timer always fires once a second
acktivity_timer.expires_from_now(boost::posix_time::seconds(1));
acktivity_timer.async_wait(
boost::bind(&Peer::handle_acktivity_timeout, shared_from_this(),
boost::asio::placeholders::error));
}
bool
Peer::check_for_activity(std::time_t current_time)
{
ostringstream msg;
// If the peer isn't using heartbeats, there's no good way to tell
// if it's still alive. It could legitimately be quiet (not send
// any DLEP messages) for a very long time. So in this case we
// just always say the peer is active.
if (peer_heartbeat_interval_sec == 0)
{
return true;
}
unsigned int heartbeat_threshold;
dlep->dlep_client.get_config_parameter("heartbeat-threshold",
&heartbeat_threshold);
// The peer is considered active for up to (heartbeat_threshold)
// of its heartbeat intervals after the last time it sent us a
// signal.
unsigned int active_time =
last_receive_time + peer_heartbeat_interval_sec * heartbeat_threshold;
if (active_time <= current_time)
{
msg << "peer=" << peer_id
<< " has been inactive for " << current_time - active_time
<< " seconds; terminating peer";
LOG(DLEP_LOG_ERROR, msg);
terminate(ProtocolStrings::Timed_Out, msg.str());
return false;
}
return true;
}
void
Peer::check_for_retransmits(std::time_t current_time)
{
ostringstream msg;
// Quick exit if we aren't waiting for any responses.
// This lets us avoid constantly asking the client for
// config parameters (below) unless they're needed.
if (responses_pending.empty())
{
return;
}
unsigned int response_timeout;
dlep->dlep_client.get_config_parameter("ack-timeout",
&response_timeout);
unsigned int send_tries;
dlep->dlep_client.get_config_parameter("send-tries",
&send_tries);
// Look at all of the active queues to see if any messages
// need to be retransmitted.
msg << "queues now active=" << responses_pending.size();
LOG(DLEP_LOG_DEBUG, msg);
for (auto & kvpair : responses_pending)
{
auto & dest_queue = kvpair.second;
if (! dest_queue.empty())
{
ResponsePendingPtr expected_response = dest_queue.front();
if (expected_response->send_time + response_timeout < current_time)
{
// We should have seen the response by now.
// If there are more tries left, send the message again.
if (expected_response->send_tries < send_tries)
{
send_message_expecting_response(expected_response);
}
else
{
msg << "Max send tries " << send_tries
<< " to peer=" << peer_id
<< " reached for signal/message that expects "
<< expected_response->response_name
<< ", terminating peer";
LOG(DLEP_LOG_ERROR, msg);
terminate(ProtocolStrings::Timed_Out, msg.str());
break;
}
} // if response is late
} // if destination queue is not empty
} // for each destination queue
}
void
Peer::handle_acktivity_timeout(const boost::system::error_code & error)
{
ostringstream msg;
boost::recursive_mutex::scoped_lock lock(dlep->mutex);
if (error)
{
msg << "boost timer error " << error;
LOG(DLEP_LOG_ERROR, msg);
if (error == boost::asio::error::operation_aborted)
{
// The timer was cancelled, which means this peer
// is shutting down. We don't want to restart the
// timer at the end of this function, so return here.
return;
}
}
else
{
// First see if this peer has been inactive for too long. If
// so, terminate the peer and don't bother doing Response
// processing.
std::time_t current_time = std::time(nullptr);
if (check_for_activity(current_time))
{
// The peer is still active. Now see if any messages need
// to be retransmitted because of the absence of a
// response from the peer.
check_for_retransmits(current_time);
} // peer is still active
} // timeout was not an error
// Set up for next time unless we are terminating.
if (pstate != PeerState::terminating)
{
schedule_acktivity_timer();
}
}
//-----------------------------------------------------------------------------
// Message sending and handling methods
/// This method can send one of four different messages depending on
/// the circumstances: Destination Up, Destination Up Response,
/// Destination Announce, or Destination Announce Response.
///
/// When called by the router:
/// If the protocol is configured to have the Destination Announce message,
/// send that, else send Destination Up.
///
/// When called by the modem:
/// If the router has previously sent a Destination Announce or Destination Up
/// message for this destination, then send the corresponding response message.
/// Otherwise, send Destination Up.
void
Peer::destination_up(const DlepMac & destination_mac,
const DataItems & initial_data_items)
{
ostringstream msg;
msg << "to peer=" << peer_id << " destination mac=" << destination_mac;
LOG(DLEP_LOG_INFO, msg);
ProtocolMessage pm {dlep->protocfg, dlep->logger};
std::string msg_name = peer_pdp->needs_response(destination_mac);
bool is_response = false;
if (msg_name != "")
{
is_response = true;
// After we finish sending this message, remember that this
// peer/destination no longer needs a response.
peer_pdp->needs_response(destination_mac, "");
}
else
{
msg_name = ProtocolStrings::Destination_Up;
// If we're the router, and the protocol is configured with the
// Destination Announce message, then use that instead of
// Destination Up.
if (! dlep->is_modem())
{
try
{
std::string m = ProtocolStrings::Destination_Announce;
(void)dlep->protocfg->get_signal_id(m);
msg_name = m;
}
catch (const ProtocolConfig::BadSignalName &)
{
// Destination_Announce is not in the protocol
// configuration, so leave msg_name as Destination_Up
}
}
}
pm.add_header(msg_name);
pm.add_mac(destination_mac);
pm.add_data_items(initial_data_items);
pm.add_common_data_items(dlep->dlep_client);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
if (is_response)
{
// Response messages don't need responses.
send_session_message(pm.get_buffer(), pm.get_length());
}
else
{
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
}
}
void
Peer::destination_down(const DlepMac & destination_mac,
const DataItems & data_items)
{
ostringstream msg;
msg << "to peer=" << peer_id << " destination mac=" << destination_mac;
LOG(DLEP_LOG_INFO, msg);
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Destination_Down);
pm.add_mac(destination_mac);
pm.add_data_items(data_items);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
}
void
Peer::destination_update(const DlepMac & mac, const DataItems & updates)
{
ostringstream msg;
msg << "to peer=" << peer_id << " destination mac=" << mac;
LOG(DLEP_LOG_INFO, msg);
if (is_not_interested(mac))
{
msg << "not sending " << ProtocolStrings::Destination_Update
<< " because peer is not interested in destination=" << mac;
LOG(DLEP_LOG_INFO, msg);
return;
}
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Destination_Update);
pm.add_mac(mac);
pm.add_data_items(updates);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
send_session_message(pm.get_buffer(), pm.get_length());
}
bool
Peer::peer_update(const DataItems & updates)
{
ostringstream msg;
// XXX_ser why do we check the state here, but not in other places?
if (pstate == PeerState::in_session)
{
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Session_Update);
pm.add_data_items(updates);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
}
else
{
msg << "Peer update not issued because peer not in session";
LOG(DLEP_LOG_ERROR, msg);
return false;
}
return true;
}
void
Peer::link_characteristics_request(const DlepMac & mac,
const DataItems & requests)
{
ostringstream msg;
msg << "to peer=" << peer_id << " mac=" << mac;
LOG(DLEP_LOG_INFO, msg);
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Link_Characteristics_Request);
pm.add_mac(mac);
pm.add_data_items(requests);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
}
void
Peer::link_characteristics_response(const DlepMac & mac, const DataItems & updates)
{
ostringstream msg;
msg << "to peer=" << peer_id << " mac=" << mac;
LOG(DLEP_LOG_INFO, msg);
if (! should_send_response(ProtocolStrings::Link_Characteristics_Response))
{
return;
}
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Link_Characteristics_Response);
pm.add_mac(mac);
pm.add_data_items(updates);
// A freshly built message should be parsable. However, this
// message contains data items that originated from the client, and
// they could be invalid. So we parse and validate the message before
// sending so that problems get logged, but we don't do anything
// drastic (assert/throw/exit) if it fails.
pm.parse_and_validate(dlep->is_modem(), __func__);
send_session_message(pm.get_buffer(), pm.get_length());
}
void
Peer::start_peer()
{
ostringstream msg;
// Create the heartbeat message one time here so that it can be
// reused each time we send one.
heartbeat_msg->add_header(ProtocolStrings::Heartbeat);
heartbeat_msg->add_common_data_items(dlep->dlep_client);
std::string err = heartbeat_msg->parse_and_validate(dlep->is_modem(),
__func__);
assert(err == "");
msg << "Heartbeat length is " << heartbeat_msg->get_length();
LOG(DLEP_LOG_DEBUG, msg);
// Start up the periodic acktivity timer. We need this running now
// because the next thing to happen in the protocol is the Peer Init/
// Peer Init Ack handshake, and we need to be able to service the ACKs
// (or lack thereof).
schedule_acktivity_timer();
// Disable Nagle's algorithm to prevent delay
boost::asio::ip::tcp::no_delay no_delay_option(true);
session_socket_->set_option(no_delay_option);
session_socket_->async_read_some(boost::asio::buffer(signal_recv_buffer,
sizeof(signal_recv_buffer)),
boost::bind(&Peer::handle_session_receive,
shared_from_this(),
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred));
// If we are the router, send the PEER_INITIALIZATION signal
if (! dlep->is_modem())
{
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Session_Initialization);
pm.add_common_data_items(dlep->dlep_client);
// fill in extensions if we have any
std::vector<ExtensionIdType> v_extid =
dlep->protocfg->get_extension_ids();
if (!v_extid.empty())
{
pm.add_extensions(v_extid);
}
// A freshly built message should be parsable.
err = pm.parse_and_validate(dlep->is_modem(), __func__);
assert(err == "");
// Give the client a chance to modify the data items in the message.
// If modified, rebuild the message with the new data items.
DataItems data_items = pm.get_data_items();
if (dlep->dlep_client.peer_init(peer_id, data_items))
{
pm.rebuild_from_data_items(dlep->is_modem(), data_items);
}
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
}
}
void
Peer::stop_peer()
{
ostringstream msg;
msg << "peer=" << peer_id;
LOG(DLEP_LOG_INFO, msg);
stop_timers();
set_state_terminating();
}
void
Peer::terminate(const std::string & status_name, const std::string & reason)
{
ostringstream msg;
msg << "peer=" << peer_id << " status=" << status_name
<< " reason=" << reason;
LOG(DLEP_LOG_INFO, msg);
if (pstate == PeerState::terminating)
{
msg << "Already in state " << pstate;
return;
}
stop_peer();
// Create and serialize a Termination message
ProtocolMessage pm {dlep->protocfg, dlep->logger};
pm.add_header(ProtocolStrings::Session_Termination);
pm.add_status(status_name, reason);
// A freshly built message should be parsable.
std::string err = pm.parse_and_validate(dlep->is_modem(), __func__);
assert(err == "");
ResponsePendingPtr rp(new ResponsePending(dlep->protocfg, pm));
send_message_expecting_response(rp);
dlep->info_base_manager->removePeer(peer_id);
// This peer will now be in state terminating, and the cleanup timer in
// Dlep.cpp will eventually remove it.
}
void
Peer::cancel_session()
{
ostringstream msg;
msg << "peer=" << peer_id;
LOG(DLEP_LOG_DEBUG, msg)
session_socket_->cancel();
}
void
Peer::schedule_heartbeat()
{
// If heartbeat-interval is 0, there will be no more heartbeats
// sent to this peer, ever. In other words, once disabled, they
// cannot be re-enabled. Changing the interval from non-zero to
// zero is probably only useful for testing.
unsigned int heartbeat_interval;
dlep->dlep_client.get_config_parameter("heartbeat-interval",
&heartbeat_interval);
if (heartbeat_interval > 0)
{
heartbeat_timer.expires_from_now(
boost::posix_time::seconds(heartbeat_interval));
heartbeat_timer.async_wait(
boost::bind(&Peer::handle_heartbeat_timeout,
shared_from_this(),
boost::asio::placeholders::error));
}
}
void
Peer::handle_heartbeat_timeout(const boost::system::error_code & error)
{
ostringstream msg;
boost::recursive_mutex::scoped_lock lock(dlep->mutex);
if (error)
{
msg << "boost timer error " << error;
LOG(DLEP_LOG_ERROR, msg);
if (error == boost::asio::error::operation_aborted)
{
// The timer was cancelled, which means this peer
// is shutting down. We don't want to restart the
// timer at the end of this function, so return here.
return;
}
}
else if (pstate == PeerState::in_session)
{
msg << "Send Heartbeat to peer ID=" << peer_id;
LOG(DLEP_LOG_INFO, msg);
send_session_message(heartbeat_msg->get_buffer(),
heartbeat_msg->get_length());
}
schedule_heartbeat();
}
void
Peer::stop_timers()
{
ostringstream msg;
msg << "stopping heartbeats to peer=" << peer_id;
LOG(DLEP_LOG_DEBUG, msg);
heartbeat_timer.cancel();
msg << "stopping acktivity timer for peer=" << peer_id;
LOG(DLEP_LOG_DEBUG, msg);
acktivity_timer.cancel();
}
void
Peer::handle_session_receive(const boost::system::error_code & error,
size_t bytes_recvd)
{
ostringstream msg;
boost::recursive_mutex::scoped_lock lock(dlep->mutex);
msg << "from peer=" << peer_id << " error=" << error
<< " bytes_recvd=" << bytes_recvd;
LOG(DLEP_LOG_INFO, msg);
if (error && error != boost::asio::error::message_size)
{
msg << "bailing out because error=" << error;
LOG(DLEP_LOG_ERROR, msg);
if (error == boost::asio::error::operation_aborted)
{
// The timer was cancelled, which means this peer is
// shutting down. We don't want to restart the async read
// at the end of this function, so return here.
return;
}
if (error == boost::asio::error::misc_errors::eof)
{
stop_peer();
// By exiting here, we skip setting up for the next read from
// this peer, which is done near the end of this method.
// We've already gotten EOF on this peer, so attempting to read
// more from it would be fruitless.
return;
}
}
else
{
// We received data from the peer, so remember the current
// time for the acktivity timer.
last_receive_time = std::time(nullptr);
// Keep track of how many bytes are now in the receive buffer.
signal_recv_len += bytes_recvd;
msg << "signal buffer now holds " << signal_recv_len
<< " bytes from the peer";
LOG(DLEP_LOG_DEBUG, msg);
// Handle all complete signals now in signal_recv_buffer.
for (;;)
{
// Overall length of the signal including the header.
std::size_t expected_msg_len;
// If we don't have enough data for a complete DLEP
// message, exit the loop. This method will
// be re-entered when we receive more data from the peer.