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fbff1eced41189c302ef888c7a799fbeff94419b
opendht/src/network_engine.cpp
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Adrien Beraud fbff1eced4 network: forget the peer ephemeral key on plaintext key advertisement 
A peer only advertises its key in plaintext when it doesn't know ours, e.g. after a restart: it lost our session, so answer with an Initial envelope.
2026-10-29 23:28:48 -04:00

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// Copyright (c) 2014-2026 Savoir-faire Linux Inc.
// SPDX-License-Identifier: MIT
#include "network_engine.h"
#include "request.h"
#include "default_types.h"
#include "logger.h"
#include "parsed_message.h"
#include <msgpack.hpp>
#include <chrono>
#include <string_view>
namespace dht {
namespace net {
using namespace std::chrono_literals;
const std::string DhtProtocolException::GET_NO_INFOHASH {"Get_values with no info_hash"};
const std::string DhtProtocolException::LISTEN_NO_INFOHASH {"Listen with no info_hash"};
const std::string DhtProtocolException::LISTEN_WRONG_TOKEN {"Listen with incorrect token"};
const std::string DhtProtocolException::PUT_NO_INFOHASH {"Put with no info_hash"};
const std::string DhtProtocolException::PUT_WRONG_TOKEN {"Put with incorrect token"};
const std::string DhtProtocolException::PUT_INVALID_ID {"Put with invalid ID"};
const std::string DhtProtocolException::STORAGE_NOT_FOUND {"Access operation for unknown storage"};
constexpr std::chrono::seconds NetworkEngine::UDP_REPLY_TIME;
constexpr std::chrono::seconds NetworkEngine::RX_MAX_PACKET_TIME;
constexpr std::chrono::seconds NetworkEngine::RX_TIMEOUT;
/* OpenDHT User Agent (UA) */
constexpr std::string_view OPENDHT_UA {"o2"};
static constexpr uint8_t v4prefix[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0};
constexpr unsigned SEND_NODES {8};
struct NetworkEngine::PartialMessage
{
SockAddr from;
time_point start;
time_point last_part;
std::unique_ptr<ParsedMessage> msg;
std::vector<std::unique_ptr<ParsedMessage>> early_parts;
size_t early_bytes {};
bool request_quota_consumed {};
};
bool
NetworkEngine::isExpectedReply(const ParsedMessage& msg, const SockAddr& from)
{
auto request = requests.find(msg.tid);
if (request != requests.end() && request->second->pending() && !request->second->node->id
&& request->second->node->getAddr() == from)
return true;
auto node = cache.getNode(msg.id, from.getFamily());
if (!node || node->getAddr() != from)
return false;
auto pending = node->getRequest(msg.tid);
return (pending && pending->pending()) || node->getSocket(msg.tid);
}
bool
NetworkEngine::tryCompleteMessage(PartialMessage& partial, const SockAddr& from)
{
try {
if (!partial.msg->complete())
return false;
process(std::move(partial.msg), from);
} catch (const std::exception& e) {
if (logger_)
logger_->warn("Error while processing partial message: {}", e.what());
} catch (...) {
if (logger_)
logger_->warn("Unknown error while processing partial message");
}
return true;
}
std::vector<Blob>
serializeValues(const std::vector<Sp<Value>>& st)
{
std::vector<Blob> svals;
svals.reserve(st.size());
for (const auto& v : st)
svals.emplace_back(packMsg(v));
return svals;
}
void
packToken(msgpack::packer<msgpack::sbuffer>& pk, const Blob& token)
{
pk.pack_bin(token.size());
pk.pack_bin_body((char*) token.data(), token.size());
}
RequestAnswer::RequestAnswer(ParsedMessage&& msg)
: values(std::move(msg.values))
, refreshed_values(std::move(msg.refreshed_values))
, expired_values(std::move(msg.expired_values))
, fields(std::move(msg.fields))
, nodes4(std::move(msg.nodes4))
, nodes6(std::move(msg.nodes6))
{
if (msg.encrypted)
ntoken.emplace();
else if (not msg.token.empty())
ntoken = std::move(msg.token);
}
NetworkEngine::NetworkEngine(InfoHash& myid,
NetworkConfig c,
std::unique_ptr<DatagramSocket>&& sock,
const Sp<Logger>& log,
std::mt19937_64& rand,
Scheduler& scheduler,
decltype(NetworkEngine::onError)&& onError,
decltype(NetworkEngine::onNewNode)&& onNewNode,
decltype(NetworkEngine::onReportedAddr)&& onReportedAddr,
decltype(NetworkEngine::onPing)&& onPing,
decltype(NetworkEngine::onFindNode)&& onFindNode,
decltype(NetworkEngine::onGetValues)&& onGetValues,
decltype(NetworkEngine::onListen)&& onListen,
decltype(NetworkEngine::onAnnounce)&& onAnnounce,
decltype(NetworkEngine::onRefresh)&& onRefresh)
: onError(std::move(onError))
, onNewNode(std::move(onNewNode))
, onReportedAddr(std::move(onReportedAddr))
, onPing(std::move(onPing))
, onFindNode(std::move(onFindNode))
, onGetValues(std::move(onGetValues))
, onListen(std::move(onListen))
, onAnnounce(std::move(onAnnounce))
, onRefresh(std::move(onRefresh))
, myid(myid)
, config(c)
, transport_(config.transport.enabled and config.transport.key)
, credential_(transport_ and config.transport.isPrivate() ? config.transport.credential.pack() : Blob {})
, dht_socket(std::move(sock))
, logger_(log)
, rd(rand)
, cache(rd)
, rate_limiter(config.max_req_per_sec)
, scheduler(scheduler)
{
epoch_.secret = transport::randomSecret();
epochRotation_ = scheduler.add(scheduler.time() + EPOCH_DURATION, std::bind(&NetworkEngine::rotateEpoch, this));
}
NetworkEngine::~NetworkEngine()
{
clear();
scheduler.cancel(epochRotation_);
epoch_.wipe();
previousEpoch_.wipe();
}
void
NetworkEngine::tellListener(const Sp<Node>& node,
Tid socket_id,
const InfoHash& hash,
want_t want,
std::vector<Sp<Node>>&& nodes,
std::vector<Sp<Node>>&& nodes6,
std::vector<Sp<Value>>&& values,
const Query& query,
int version)
{
auto nnodes = bufferNodes(node->getFamily(), hash, want, nodes, nodes6);
auto ntoken = writeToken(*node);
try {
if (version >= 1) {
sendUpdateValues(node, hash, std::move(values), scheduler.time(), ntoken, socket_id);
} else {
sendNodesValues(*node, node->getAddr(), socket_id, nnodes, std::move(values), query, ntoken);
}
} catch (const std::overflow_error& e) {
if (logger_)
logger_->error("Unable to send value: buffer not large enough.");
}
}
void
NetworkEngine::tellListenerRefreshed(const Sp<Node>& n,
Tid socket_id,
const InfoHash&,
const std::vector<Value::Id>& values,
int version)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
auto token = writeToken(*n);
pk.pack_map(4 + (version >= 1 ? 1 : 0) + optionalFields(advertise));
pk.pack(version >= 1 ? KEY_A : KEY_U);
pk.pack_map(1 + (version >= 1 ? 1 : 0) + (not values.empty() ? 1 : 0) + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
if (version >= 1) {
pk.pack(KEY_REQ_SID);
pk.pack(socket_id);
}
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
packToken(pk, token);
}
if (not values.empty()) {
pk.pack(KEY_REQ_REFRESHED);
pk.pack(values);
if (logger_)
logger_->debug("[node {}] sending {} refreshed values", n->toString(), values.size());
}
pk.pack(KEY_Y);
pk.pack(version >= 1 ? KEY_Q : KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
if (version >= 1) {
Tid tid(n->getNewTid());
pk.pack(KEY_Q);
pk.pack(QUERY_UPDATE);
pk.pack(KEY_TID);
pk.pack(tid);
auto req = std::make_shared<Request>(
MessageType::UpdateValue,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request&, ParsedMessage&&) { /* on done */ },
[=](const Request&, bool) { /* on expired */ });
sendRequest(req);
++out_stats.updateValue;
return;
}
pk.pack(KEY_TID);
pk.pack(socket_id);
// send response
send(*n, n->getAddr(), buffer.data(), buffer.size());
}
void
NetworkEngine::tellListenerExpired(const Sp<Node>& n,
Tid socket_id,
const InfoHash&,
const std::vector<Value::Id>& values,
int version)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
auto token = writeToken(*n);
pk.pack_map(4 + (version >= 1 ? 1 : 0) + optionalFields(advertise));
pk.pack(version >= 1 ? KEY_A : KEY_U);
pk.pack_map(1 + (version >= 1 ? 1 : 0) + (not values.empty() ? 1 : 0) + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
if (version >= 1) {
pk.pack(KEY_REQ_SID);
pk.pack(socket_id);
}
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
packToken(pk, token);
}
if (not values.empty()) {
pk.pack(KEY_REQ_EXPIRED);
pk.pack(values);
if (logger_)
logger_->debug("[node {}] sending {} expired values", n->toString(), values.size());
}
pk.pack(KEY_Y);
pk.pack(version >= 1 ? KEY_Q : KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
if (version >= 1) {
Tid tid(n->getNewTid());
pk.pack(KEY_Q);
pk.pack(QUERY_UPDATE);
pk.pack(KEY_TID);
pk.pack(tid);
auto req = std::make_shared<Request>(
MessageType::UpdateValue,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request&, ParsedMessage&&) { /* on done */ },
[=](const Request&, bool) { /* on expired */ });
sendRequest(req);
++out_stats.updateValue;
return;
}
pk.pack(KEY_TID);
pk.pack(socket_id);
// send response
send(*n, n->getAddr(), buffer.data(), buffer.size());
}
bool
NetworkEngine::isRunning(sa_family_t af) const
{
switch (af) {
case 0:
return dht_socket->hasIPv4() or dht_socket->hasIPv6();
case AF_INET:
return dht_socket->hasIPv4();
case AF_INET6:
return dht_socket->hasIPv6();
default:
return false;
}
}
void
NetworkEngine::clear()
{
for (auto& request : requests) {
request.second->cancel();
request.second->node->setExpired();
}
requests.clear();
partial_messages.clear();
}
void
NetworkEngine::connectivityChanged(sa_family_t af)
{
cache.clearBadNodes(af);
}
void
NetworkEngine::requestStep(Sp<Request> sreq)
{
auto& req = *sreq;
if (not req.pending())
return;
auto now = scheduler.time();
auto& node = *req.node;
if (req.isExpired(now)) {
// if (logger_)
// logger_->d(node.id, "[node %s] expired.", node.toString().c_str());
node.setExpired();
if (not node.id)
requests.erase(req.tid);
return;
} else if (req.attempt_count == 1) {
if (req.on_expired)
req.on_expired(req, false);
// The peer may have lost our ephemeral key or credential: retry with an Initial envelope
if (const auto& peer = node.getTransport())
peer->ephemeral.reset();
}
auto err = send(node,
node.getAddr(),
(char*) req.msg.data(),
req.msg.size(),
node.getReplyTime() < now - UDP_REPLY_TIME);
if (err == ENETUNREACH || err == EHOSTUNREACH || err == EAFNOSUPPORT || err == EPIPE || err == EPERM) {
node.setExpired();
if (not node.id)
requests.erase(req.tid);
} else {
req.last_try = now;
if (err != EAGAIN) {
++req.attempt_count;
req.attempt_duration += req.attempt_duration
+ uniform_duration_distribution<>(0ms, ((duration) Node::MAX_RESPONSE_TIME) / 4)(rd);
if (not req.parts.empty()) {
sendValueParts(req.tid, req.parts, node, node.getAddr());
}
}
std::weak_ptr<Request> wreq = sreq;
scheduler.add(req.last_try + req.attempt_duration, [this, wreq] {
if (auto req = wreq.lock())
requestStep(req);
});
}
}
/**
* Sends a request to a node. Request::MAX_ATTEMPT_COUNT attempts will
* be made before the request expires.
*/
void
NetworkEngine::sendRequest(const Sp<Request>& request)
{
auto& node = *request->node;
if (not node.id)
requests.emplace(request->tid, request);
request->start = scheduler.time();
node.requested(request);
requestStep(request);
}
/* Rate control for requests we receive. */
bool
NetworkEngine::rateLimit(const SockAddr& addr)
{
const auto& now = scheduler.time();
// occasional IP limiter maintenance (a few times every second at max rate)
if (limiter_maintenance++ == config.max_peer_req_per_sec) {
for (auto it = address_rate_limiter.begin(); it != address_rate_limiter.end();) {
if (it->second.maintain(now) == 0)
address_rate_limiter.erase(it++);
else
++it;
}
limiter_maintenance = 0;
}
// invoke per IP, then global rate limiter
return (config.max_peer_req_per_sec < 0
or address_rate_limiter.emplace(addr, config.max_peer_req_per_sec).first->second.limit(now))
and rate_limiter.limit(now);
}
bool
NetworkEngine::isMartian(const SockAddr& addr)
{
if (addr.getPort() == 0)
return true;
switch (addr.getFamily()) {
case AF_INET: {
const auto& sin = addr.getIPv4();
const uint8_t* address = (const uint8_t*) &sin.sin_addr;
return (address[0] == 0) || ((address[0] & 0xE0) == 0xE0);
}
case AF_INET6: {
if (addr.getLength() < sizeof(sockaddr_in6))
return true;
const auto& sin6 = addr.getIPv6();
const uint8_t* address = (const uint8_t*) &sin6.sin6_addr;
return address[0] == 0xFF || memcmp(address, InfoHash::zero().data(), 16) == 0
|| memcmp(address, v4prefix, 12) == 0;
}
default:
return true;
}
}
/* The internal blacklist is an LRU cache of nodes that have sent
incorrect messages. */
void
NetworkEngine::blacklistNode(const Sp<Node>& n)
{
n->setExpired();
blacklist.emplace(n->getAddr());
}
bool
NetworkEngine::isNodeBlacklisted(const SockAddr& addr) const
{
return blacklist.find(addr) != blacklist.end();
}
void
NetworkEngine::processMessage(const uint8_t* buf, size_t buflen, SockAddr f)
{
auto from = f.getMappedIPv4();
if (isMartian(from)) {
if (logger_)
logger_->warn("Received packet from martian node {}", from.toString());
return;
}
if (isNodeBlacklisted(from)) {
if (logger_)
logger_->warn("Received packet from blacklisted node {}", from.toString());
return;
}
std::optional<OpenedEnvelope> envelope;
if (transport::isEnvelope(buf, buflen)) {
if (not transport_)
return;
envelope = openEnvelope(buf, buflen, from);
if (not envelope)
return;
buf = envelope->payload.data();
buflen = envelope->payload.size();
} else if (transport_ and config.transport.isPrivate()) {
return;
}
auto msg = std::make_unique<ParsedMessage>();
try {
msgpack::unpacked msg_res = msgpack::unpack((const char*) buf, buflen);
msg->msgpack_unpack(msg_res.get());
} catch (const std::exception& e) {
if (logger_)
logger_->warn("Unable to parse message of size {}: {}", buflen, e.what());
// if (logger_)
// logger_->DBG.logPrintable(buf, buflen);
return;
}
if (msg->network != config.network) {
if (logger_)
logger_->debug("Received message from other config.network {}", msg->network);
return;
}
if (envelope) {
// value fragments carry no node ID
if (msg->type != MessageType::ValueData and msg->id != transport::nodeId(envelope->peer->key)) {
if (logger_)
logger_->warn("Dropping encrypted message from {}: node ID doesn't match its key", from.toString());
return;
}
if (envelope->hello) {
processHello(*msg, envelope->peer, from);
return;
}
msg->peer = std::move(envelope->peer);
msg->encrypted = true;
msg->session = envelope->session;
} else if (transport_ and msg->transport_key) {
msg->peer = makePeer(msg->id, *msg->transport_key);
}
const auto& now = scheduler.time();
// partial value data
if (msg->type == MessageType::ValueData) {
if (msg->fragment_parts.empty()
|| std::any_of(msg->fragment_parts.begin(), msg->fragment_parts.end(), [](const auto& fragment) {
return fragment.second.second.empty();
})) {
rateLimit(from);
return;
}
PartialMessageKey key {from, msg->tid};
auto pmsg_it = partial_messages.find(key);
if (pmsg_it == partial_messages.end()) {
if (!rateLimit(from))
return;
auto inserted = partial_messages.emplace(key, PartialMessage {});
pmsg_it = inserted.first;
pmsg_it->second.from = from;
pmsg_it->second.start = now;
pmsg_it->second.last_part = now;
pmsg_it->second.request_quota_consumed = true;
scheduler.add(now + RX_MAX_PACKET_TIME, std::bind(&NetworkEngine::maintainRxBuffer, this, key));
}
auto& pmsg = pmsg_it->second;
if (!pmsg.msg) {
if (pmsg.early_parts.size() >= RX_MAX_EARLY_PARTS) {
partial_messages.erase(pmsg_it);
return;
}
size_t fragment_bytes {};
for (const auto& [index, fragment] : msg->fragment_parts) {
(void) index;
if (fragment.second.size() > RX_MAX_EARLY_BYTES - fragment_bytes) {
partial_messages.erase(pmsg_it);
return;
}
fragment_bytes += fragment.second.size();
}
if (fragment_bytes > RX_MAX_EARLY_BYTES - pmsg.early_bytes) {
partial_messages.erase(pmsg_it);
return;
}
pmsg.early_bytes += fragment_bytes;
pmsg.early_parts.emplace_back(std::move(msg));
pmsg.last_part = now;
scheduler.add(now + RX_TIMEOUT, std::bind(&NetworkEngine::maintainRxBuffer, this, key));
return;
}
// append data block
if (pmsg.msg->append(*msg)) {
pmsg.last_part = now;
if (tryCompleteMessage(pmsg, from)) {
partial_messages.erase(pmsg_it);
} else
scheduler.add(now + RX_TIMEOUT, std::bind(&NetworkEngine::maintainRxBuffer, this, key));
}
return;
}
if (msg->id == myid or not msg->id) {
if (logger_)
logger_->debug("Received message from self");
return;
}
if (msg->value_parts.empty()) {
if (msg->type > MessageType::Reply) {
/* Rate limit requests. */
if (!rateLimit(from)) {
if (logger_)
logger_->warn("Dropping request due to rate limiting");
return;
}
}
try {
process(std::move(msg), from);
} catch (const std::exception& e) {
if (logger_)
logger_->warn("Error while processing message: {}", e.what());
}
return;
}
PartialMessageKey partial_key {from, msg->tid};
if (msg->type == MessageType::Reply && !isExpectedReply(*msg, from))
return;
const auto partial = partial_messages.find(partial_key);
const bool request_quota_consumed = partial != partial_messages.end() && !partial->second.msg
&& partial->second.request_quota_consumed;
if (msg->type > MessageType::Reply && !request_quota_consumed) {
/* Rate limit requests. */
if (!rateLimit(from)) {
if (logger_)
logger_->warn("Dropping request due to rate limiting");
return;
}
}
// starting partial message session
auto inserted = partial_messages.emplace(partial_key, PartialMessage {});
auto& pmsg = inserted.first->second;
if (not pmsg.msg) {
if (inserted.second) {
pmsg.from = from;
pmsg.start = now;
scheduler.add(now + RX_MAX_PACKET_TIME, std::bind(&NetworkEngine::maintainRxBuffer, this, partial_key));
}
pmsg.msg = std::move(msg);
pmsg.last_part = now;
for (const auto& part : pmsg.early_parts)
pmsg.msg->append(*part);
pmsg.early_parts.clear();
pmsg.early_bytes = 0;
if (tryCompleteMessage(pmsg, from)) {
partial_messages.erase(inserted.first);
} else {
scheduler.add(now + RX_TIMEOUT, std::bind(&NetworkEngine::maintainRxBuffer, this, partial_key));
}
} else if (logger_)
logger_->error("Partial message from {} with given TID {} already exists", from.toString(), msg->tid);
}
void
NetworkEngine::process(std::unique_ptr<ParsedMessage>&& msg, const SockAddr& from)
{
const auto& now = scheduler.time();
// Plaintext can be spoofed: it never moves a node known to support encryption to a new address.
Sp<Node> node;
bool trusted = msg->encrypted;
if (not trusted) {
node = cache.getNode(msg->id, from.getFamily());
if (not node or not node->getTransport() or node->getAddr() == from) {
node.reset();
trusted = true;
}
}
if (not node)
node = cache.getNode(msg->id, from, now, true, msg->is_client);
if (msg->peer)
attachPeer(*node, msg->peer);
// Advertising its key in plaintext, the peer shows it lost our session, e.g. after a restart
if (trusted and not msg->encrypted and msg->transport_key)
if (const auto& peer = node->getTransport())
peer->ephemeral.reset();
if (msg->type == MessageType::ValueUpdate) {
if (not trusted)
return;
auto rsocket = node->getSocket(msg->tid);
if (not rsocket)
throw DhtProtocolException {DhtProtocolException::UNKNOWN_TID, "Unable to find socket", msg->id};
node->received(now, {});
onNewNode(node, 2);
try {
deserializeNodes(*msg, from);
rsocket->on_receive(node, std::move(*msg));
} catch (const DhtProtocolException& e) {
if (logger_)
logger_->warn("Unable to deserialize nodes {}", e.what());
}
} else if (msg->type == MessageType::Error or msg->type == MessageType::Reply) {
if (not trusted)
return;
auto rsocket = node->getSocket(msg->tid);
auto req = node->getRequest(msg->tid);
// Our request reached the peer in an envelope it accepted, and it answered with the session keys
if (msg->session and req) {
const auto& peer = node->getTransport();
if (auto s = peer and peer->ephemeral ? epoch_.find(from, peer->key, *peer->ephemeral) : nullptr)
s->confirmed = true;
}
/* either response for a request or data for an opened socket */
if (not req and not rsocket) {
auto req_it = requests.find(msg->tid);
if (req_it != requests.end() and not req_it->second->node->id) {
req = req_it->second;
req->node = node;
requests.erase(req_it);
} else {
node->received(now, req);
if (not node->isClient())
onNewNode(node, 1);
if (logger_)
logger_->debug("[node {}] Unable to find transaction with id {}", node->toString(), msg->tid);
return;
}
}
node->received(now, req);
if (not node->isClient())
onNewNode(node, 2);
onReportedAddr(msg->id, msg->addr);
if (req and (req->cancelled() or req->expired() or req->completed())) {
if (logger_)
logger_->warn("[node {}] response to expired, cancelled or completed request", node->toString());
return;
}
switch (msg->type) {
case MessageType::Error: {
if (msg->id and req
and ((msg->error_code == DhtProtocolException::NOT_FOUND and req->getType() == MessageType::Refresh)
or (msg->error_code == DhtProtocolException::UNAUTHORIZED
and (req->getType() == MessageType::AnnounceValue or req->getType() == MessageType::Listen)))) {
req->last_try = time_point::min();
req->reply_time = time_point::min();
if (not req->setError(DhtProtocolException {msg->error_code}))
onError(req, DhtProtocolException {msg->error_code});
} else {
if (logIncoming_)
if (logger_)
logger_->warn("[node {} {}] received unknown error message {}",
msg->id.toString(),
from.toString(),
msg->error_code);
}
break;
}
case MessageType::Reply:
if (req) { /* request reply */
auto& r = *req;
if (r.getType() == MessageType::AnnounceValue or r.getType() == MessageType::Listen
or r.getType() == MessageType::Refresh) {
r.node->authSuccess();
}
r.reply_time = scheduler.time();
try {
deserializeNodes(*msg, from);
r.setDone(std::move(*msg));
} catch (const DhtProtocolException& e) {
if (logger_)
logger_->warn("Unable to deserialize nodes {}", e.what());
}
break;
} else { /* request socket data */
try {
deserializeNodes(*msg, from);
rsocket->on_receive(node, std::move(*msg));
} catch (const DhtProtocolException& e) {
if (logger_)
logger_->warn("Unable to deserialize nodes {}", e.what());
}
}
break;
default:
break;
}
} else {
if (trusted) {
node->received(now, {});
if (not node->isClient())
onNewNode(node, 1);
}
try {
switch (msg->type) {
case MessageType::Ping:
++in_stats.ping;
if (logIncoming_)
if (logger_)
logger_->debug("[node {}] sending pong", node->toString());
onPing(node);
sendPong(*node, from, msg->tid);
break;
case MessageType::FindNode: {
// if (logger_)
// logger_->d("[node %s] got 'find' request for %s (%d)",
// node->toString().c_str(), msg->target.toString().c_str(), msg->want);
++in_stats.find;
RequestAnswer answer = onFindNode(node, msg->target, msg->want);
auto nnodes = bufferNodes(from.getFamily(), msg->target, msg->want, answer.nodes4, answer.nodes6);
sendNodesValues(*node, from, msg->tid, nnodes, {}, {}, writeToken(*node));
break;
}
case MessageType::GetValues: {
// if (logger_)
// logger_->d("[node %s] got 'get' request for %s",
// node->toString().c_str(), msg->info_hash.toString().c_str());
++in_stats.get;
RequestAnswer answer = onGetValues(node, msg->info_hash, msg->want, msg->query);
auto nnodes = bufferNodes(from.getFamily(), msg->info_hash, msg->want, answer.nodes4, answer.nodes6);
sendNodesValues(*node, from, msg->tid, nnodes, answer.values, msg->query, writeToken(*node));
break;
}
case MessageType::AnnounceValue: {
if (logIncoming_ and logger_)
logger_->debug("[node {}] got 'put' request for {}", node->toString(), msg->info_hash.toString());
++in_stats.put;
authorizeWrite(*msg, *node, DhtProtocolException::PUT_WRONG_TOKEN);
onAnnounce(node, msg->info_hash, msg->values, msg->created);
/* Note that if storageStore failed, we lie to the requestor.
This is to prevent them from backtracking, and hence
polluting the DHT. */
for (auto& v : msg->values) {
sendValueAnnounced(*node, from, msg->tid, v->id);
}
break;
}
case MessageType::Refresh:
if (logIncoming_ and logger_)
logger_->debug("[node {}] got 'refresh' request for {}",
node->toString(),
msg->info_hash.toString());
authorizeWrite(*msg, *node, DhtProtocolException::PUT_WRONG_TOKEN);
onRefresh(node, msg->info_hash, msg->value_id);
/* Same note as above in MessageType::AnnounceValue applies. */
sendValueAnnounced(*node, from, msg->tid, msg->value_id);
break;
case MessageType::Listen: {
if (logIncoming_ and logger_)
logger_->debug("[node {}] got 'listen' request for {}", node->toString(), msg->info_hash.toString());
++in_stats.listen;
authorizeWrite(*msg, *node, DhtProtocolException::LISTEN_WRONG_TOKEN);
RequestAnswer answer = onListen(node,
msg->info_hash,
msg->socket_id,
std::move(msg->query),
msg->version);
auto nnodes = bufferNodes(from.getFamily(), msg->info_hash, msg->want, answer.nodes4, answer.nodes6);
sendListenConfirmation(*node, from, msg->tid, writeToken(*node));
break;
}
case MessageType::UpdateValue: {
if (logIncoming_ and logger_)
logger_->debug("[node {}] got 'update' request for {}", node->toString(), msg->info_hash.toString());
++in_stats.updateValue;
if (auto rsocket = node->getSocket(msg->socket_id))
rsocket->on_receive(node, std::move(*msg));
else if (logger_)
logger_->error("[node {}] 'update' request without socket for {}",
node->toString(),
msg->info_hash.toString());
sendListenConfirmation(*node, from, msg->tid);
break;
}
default:
break;
}
} catch (const std::overflow_error& e) {
if (logger_)
logger_->e("Unable to send value: buffer not large enough.");
} catch (const DhtProtocolException& e) {
sendError(*node, from, msg->tid, e.getCode(), e.getMsg().c_str(), true);
}
}
}
void
insertAddr(msgpack::packer<msgpack::sbuffer>& pk, const SockAddr& addr)
{
size_t addr_len = std::min<size_t>(addr.getLength(),
(addr.getFamily() == AF_INET) ? sizeof(in_addr) : sizeof(in6_addr));
void* addr_ptr = (addr.getFamily() == AF_INET) ? (void*) &addr.getIPv4().sin_addr
: (void*) &addr.getIPv6().sin6_addr;
pk.pack("sa");
pk.pack_bin(addr_len);
pk.pack_bin_body((char*) addr_ptr, addr_len);
}
void
NetworkEngine::packOptionalFields(msgpack::packer<msgpack::sbuffer>& pk, bool key) const
{
if (config.network) {
pk.pack(KEY_NETID);
pk.pack(config.network);
}
if (config.is_client) {
pk.pack(KEY_ISCLIENT);
pk.pack(config.is_client);
}
if (key) {
const auto& pub = config.transport.key.pub;
pk.pack(KEY_TRANSPORT);
pk.pack_bin(pub.size());
pk.pack_bin_body((const char*) pub.data(), pub.size());
}
}
/* IP and port: what ephemeral keys and tokens are bound to */
static Blob
addressBytes(const SockAddr& sa)
{
auto addr = SockAddr(sa).getMappedIPv4();
Blob b;
in_port_t port;
if (addr.getFamily() == AF_INET) {
const auto& sin = addr.getIPv4();
b.assign((const uint8_t*) &sin.sin_addr, (const uint8_t*) &sin.sin_addr + sizeof(in_addr));
port = sin.sin_port;
} else if (addr.getFamily() == AF_INET6) {
const auto& sin6 = addr.getIPv6();
b.assign((const uint8_t*) &sin6.sin6_addr, (const uint8_t*) &sin6.sin6_addr + sizeof(in6_addr));
port = sin6.sin6_port;
} else {
return b;
}
b.insert(b.end(), (const uint8_t*) &port, (const uint8_t*) &port + sizeof(port));
return b;
}
transport::KeyPair
NetworkEngine::Epoch::ephemeral(const SockAddr& addr) const
{
auto a = addressBytes(addr);
return transport::addressKey(secret, a.data(), a.size());
}
Blob
NetworkEngine::Epoch::token(const SockAddr& addr) const
{
auto a = addressBytes(addr);
if (a.empty())
return {};
auto t = transport::addressToken(secret, a.data(), a.size());
return {t.begin(), t.end()};
}
NetworkEngine::Session*
NetworkEngine::Epoch::find(const SockAddr& addr)
{
auto it = sessions.find(addr);
return it != sessions.end() ? &it->second : nullptr;
}
NetworkEngine::Session*
NetworkEngine::Epoch::find(const SockAddr& addr, const transport::Key& peer, const transport::Key& peerEphemeral)
{
auto s = find(addr);
return s and s->peer == peer and s->peerEphemeral == peerEphemeral ? s : nullptr;
}
void
NetworkEngine::Epoch::store(const SockAddr& addr, const Session& session)
{
auto it = sessions.find(addr);
if (it == sessions.end()) {
// A peer we sent keys to must keep them, or its Data envelopes are lost
if (sessions.size() >= MAX_SESSIONS) {
transport::wipe(sessions.begin()->second.keys.tx);
transport::wipe(sessions.begin()->second.keys.rx);
sessions.erase(sessions.begin());
}
sessions.emplace(addr, session);
return;
}
transport::wipe(it->second.keys.tx);
transport::wipe(it->second.keys.rx);
it->second = session;
}
void
NetworkEngine::Epoch::wipe()
{
for (auto& [addr, session] : sessions) {
(void) addr;
transport::wipe(session.keys.tx);
transport::wipe(session.keys.rx);
}
sessions.clear();
transport::wipe(secret);
}
void
NetworkEngine::rotateEpoch()
{
previousEpoch_.wipe();
previousEpoch_.secret = epoch_.secret;
previousEpoch_.sessions = std::move(epoch_.sessions);
epoch_.sessions.clear();
epoch_.secret = transport::randomSecret();
epochRotation_ = scheduler.add(scheduler.time() + EPOCH_DURATION, std::bind(&NetworkEngine::rotateEpoch, this));
}
std::optional<NetworkEngine::Session>
NetworkEngine::session(const transport::Peer& peer, const SockAddr& addr)
{
const auto& peerEphemeral = *peer.ephemeral;
if (auto s = epoch_.find(addr, peer.key, peerEphemeral))
return *s;
auto ephemeral = epoch_.ephemeral(addr);
std::optional<Session> s;
if (auto keys = transport::sessionKeys(config.transport.key, ephemeral, peer.key, peerEphemeral, config.network)) {
s = Session {ephemeral.pub, peer.key, peerEphemeral, *keys};
epoch_.store(addr, *s);
}
transport::wipe(ephemeral.secret);
return s;
}
std::optional<Blob>
NetworkEngine::openSession(const transport::Header& header, const uint8_t* buf, size_t buflen, const SockAddr& from)
{
// The sender uses the last ephemeral key we sent to its address
const std::array<Epoch*, 2> epochs {&epoch_, &previousEpoch_};
for (auto* epoch : epochs)
if (auto cached = epoch->find(from, header.sender, header.ephemeral))
if (auto payload = transport::open(cached->keys.rx, buf, buflen))
return payload;
for (auto* epoch : epochs) {
if (not *epoch or epoch->find(from, header.sender, header.ephemeral))
continue;
// Key agreement is the costly part of an unknown sender
if (not rateLimit(from))
return std::nullopt;
auto ephemeral = epoch->ephemeral(from);
auto keys = transport::sessionKeys(config.transport.key,
ephemeral,
header.sender,
header.ephemeral,
config.network);
transport::wipe(ephemeral.secret);
if (not keys)
return std::nullopt;
if (auto payload = transport::open(keys->rx, buf, buflen)) {
epoch->store(from, Session {ephemeral.pub, header.sender, header.ephemeral, *keys});
return payload;
}
transport::wipe(keys->tx);
transport::wipe(keys->rx);
}
return std::nullopt;
}
std::optional<Blob>
NetworkEngine::openData(transport::Header& header, const uint8_t* buf, size_t buflen, const SockAddr& from)
{
for (auto* epoch : {&epoch_, &previousEpoch_}) {
auto s = epoch->find(from);
if (not s)
continue;
if (auto payload = transport::open(s->keys.rx, buf, buflen)) {
// The peer only sends Data once it got our answer: it has the keys and accepted us
if (epoch == &epoch_)
s->confirmed = true;
header.sender = s->peer;
header.ephemeral = s->peerEphemeral;
return payload;
}
}
return std::nullopt;
}
bool
NetworkEngine::tokenMatch(const Blob& token, const SockAddr& addr) const
{
if (not addr or token.size() != TOKEN_SIZE)
return false;
return token == epoch_.token(addr) or (previousEpoch_ and token == previousEpoch_.token(addr));
}
void
NetworkEngine::authorizeWrite(const ParsedMessage& msg, const Node& node, const std::string& error) const
{
if (msg.encrypted ? msg.session : tokenMatch(msg.token, node.getAddr()))
return;
if (logger_)
logger_->warn("[node {}] {}", node.toString(), error);
throw DhtProtocolException {DhtProtocolException::UNAUTHORIZED, error};
}
Sp<transport::Peer>
NetworkEngine::makePeer(const InfoHash& id, const transport::Key& key) const
{
if (key == transport::Key {} or transport::nodeId(key) != id)
return {};
return std::make_shared<transport::Peer>(key);
}
void
NetworkEngine::attachPeer(Node& node, const Sp<transport::Peer>& peer)
{
const auto& current = node.getTransport();
if (not current) {
node.setTransport(peer);
} else if (current != peer) {
// Both keys match the node ID, so they are the same
current->authorizedUntil = std::max(current->authorizedUntil, peer->authorizedUntil);
if (peer->ephemeral)
current->ephemeral = peer->ephemeral;
}
}
bool
NetworkEngine::authorize(transport::Peer& peer, const uint8_t* data, size_t size) const
{
if (peer.isAuthorized(std::chrono::system_clock::now()))
return true;
try {
auto credential = transport::Credential::unpack(data, size);
if (credential.key != peer.key or not credential.verify(config.transport.authorities))
return false;
peer.authorizedUntil = credential.expiration;
return true;
} catch (const std::exception&) {
return false;
}
}
std::optional<NetworkEngine::OpenedEnvelope>
NetworkEngine::openEnvelope(const uint8_t* buf, size_t buflen, const SockAddr& from)
{
using transport::EnvelopeType;
constexpr size_t CREDENTIAL_SIZE = transport::Credential::PACKED_SIZE;
auto header = transport::parseHeader(buf, buflen);
if (not header or header->sender == config.transport.key.pub)
return std::nullopt;
const bool isPrivate = config.transport.isPrivate();
if (header->type == EnvelopeType::Hello) {
// Unauthenticated: its state is only used to answer, never kept
constexpr size_t credentialEnd = transport::HEADER_SIZE + CREDENTIAL_SIZE;
auto peer = std::make_shared<transport::Peer>(header->sender);
if (not isPrivate or buflen <= credentialEnd or not rateLimit(from)
or not authorize(*peer, buf + transport::HEADER_SIZE, CREDENTIAL_SIZE))
return std::nullopt;
peer->ephemeral = header->ephemeral;
return OpenedEnvelope {std::move(peer), Blob(buf + credentialEnd, buf + buflen), true};
}
std::optional<Blob> payload;
if (header->type == EnvelopeType::Initial) {
if (not rateLimit(from))
return std::nullopt;
if (auto key = transport::initialReceiveKey(config.transport.key,
header->sender,
header->ephemeral,
config.network))
payload = transport::open(*key, buf, buflen);
// The sender lost our ephemeral key, and maybe the session
if (payload)
if (auto s = epoch_.find(from))
s->confirmed = false;
} else if (header->type == EnvelopeType::Data) {
payload = openData(*header, buf, buflen, from);
} else {
payload = openSession(*header, buf, buflen, from);
}
if (not payload) {
if (logger_)
logger_->debug("Unable to decrypt message from {}", from.toString());
return std::nullopt;
}
Sp<transport::Peer> peer;
if (auto node = cache.getNode(transport::nodeId(header->sender), from.getFamily()))
peer = node->getTransport();
if (not peer)
peer = std::make_shared<transport::Peer>(header->sender);
if (header->credential) {
if (payload->size() < CREDENTIAL_SIZE or (isPrivate and not authorize(*peer, payload->data(), CREDENTIAL_SIZE)))
return std::nullopt;
payload->erase(payload->begin(), payload->begin() + CREDENTIAL_SIZE);
} else if (isPrivate and not peer->isAuthorized(std::chrono::system_clock::now())) {
return std::nullopt;
}
peer->ephemeral = header->ephemeral;
return OpenedEnvelope {std::move(peer), std::move(*payload), false, header->type != EnvelopeType::Initial};
}
void
NetworkEngine::processHello(const ParsedMessage& msg, const Sp<transport::Peer>& peer, const SockAddr& from)
{
if (msg.type != MessageType::Ping)
return;
++in_stats.ping;
// Answer without adding the claimed node: only the owner of its key can read the answer
Node node(msg.id, from, rd);
node.setTransport(peer);
sendPong(node, from, msg.tid);
}
int
NetworkEngine::sendRaw(const SockAddr& addr, const uint8_t* buf, size_t len, bool confirmed)
{
return dht_socket ? dht_socket->sendTo(addr, buf, len, confirmed) : ENOTCONN;
}
int
NetworkEngine::send(const Node& node, const SockAddr& addr, const char* buf, size_t len, bool confirmed)
{
using transport::EnvelopeType;
const auto data = (const uint8_t*) buf;
if (not transport_)
return sendRaw(addr, data, len, confirmed);
const bool isPrivate = config.transport.isPrivate();
const auto& own = config.transport.key;
if (const auto& peer = node.getTransport()) {
// Keys travel until the peer confirms the session, and the credential with them
Blob packet;
if (not peer->ephemeral) {
auto e = epoch_.ephemeral(addr);
if (auto key = transport::initialSendKey(own, e, peer->key, config.network)) {
packet = transport::seal(*key,
EnvelopeType::Initial,
own.pub,
e.pub,
data,
len,
isPrivate ? credential_ : Blob {});
transport::wipe(*key);
}
transport::wipe(e.secret);
} else if (auto s = session(*peer, addr)) {
packet = s->confirmed ? transport::sealData(s->keys.tx, data, len)
: transport::seal(s->keys.tx,
EnvelopeType::Session,
own.pub,
s->ephemeral,
data,
len,
isPrivate ? credential_ : Blob {});
transport::wipe(s->keys.tx);
transport::wipe(s->keys.rx);
}
if (not packet.empty())
return sendRaw(addr, packet.data(), packet.size(), confirmed);
} else if (isPrivate and not node.id) {
// ping to an address: introduce ourselves
auto e = epoch_.ephemeral(addr);
transport::wipe(e.secret);
auto packet = transport::hello(own.pub, e.pub, credential_, data, len);
return sendRaw(addr, packet.data(), packet.size(), confirmed);
}
if (isPrivate)
return EPERM;
return sendRaw(addr, data, len, confirmed);
}
Sp<Request>
NetworkEngine::sendPing(const Sp<Node>& node, RequestCb&& on_done, RequestExpiredCb&& on_expired)
{
Tid tid(node->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*node);
pk.pack_map(5 + optionalFields(advertise));
pk.pack(KEY_A);
pk.pack_map(1);
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_Q);
pk.pack(QUERY_PING);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::Ping,
tid,
node,
Blob(buffer.data(), buffer.data() + buffer.size()),
[this, on_done = std::move(on_done)](const Request& req_status, ParsedMessage&&) {
if (logger_)
logger_->debug("[node {}] got pong.", req_status.node->toString());
if (on_done) {
on_done(req_status, {});
}
},
std::move(on_expired));
sendRequest(req);
++out_stats.ping;
return req;
}
void
NetworkEngine::sendPong(const Node& node, const SockAddr& addr, Tid tid)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(node);
pk.pack_map(4 + optionalFields(advertise));
pk.pack(KEY_R);
pk.pack_map(2);
pk.pack(KEY_REQ_ID);
pk.pack(myid);
insertAddr(pk, addr);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
send(node, addr, buffer.data(), buffer.size());
}
Sp<Request>
NetworkEngine::sendFindNode(
const Sp<Node>& n, const InfoHash& target, want_t want, RequestCb&& on_done, RequestExpiredCb&& on_expired)
{
Tid tid(n->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
pk.pack(KEY_A);
pk.pack_map(2 + (want > 0 ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_REQ_TARGET);
pk.pack(target);
if (want > 0) {
pk.pack(KEY_REQ_WANT);
pk.pack_array(((want & WANT4) ? 1 : 0) + ((want & WANT6) ? 1 : 0));
if (want & WANT4)
pk.pack(AF_INET);
if (want & WANT6)
pk.pack(AF_INET6);
}
pk.pack(KEY_Q);
pk.pack(QUERY_FIND);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::FindNode,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request& req_status, ParsedMessage&& msg) { /* on done */
if (on_done) {
on_done(req_status,
{std::forward<ParsedMessage>(msg)});
}
},
std::move(on_expired));
sendRequest(req);
++out_stats.find;
return req;
}
Sp<Request>
NetworkEngine::sendGetValues(const Sp<Node>& n,
const InfoHash& info_hash,
const Query& query,
want_t want,
RequestCb&& on_done,
RequestExpiredCb&& on_expired)
{
Tid tid(n->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
unsigned sendQuery = (not query.where.empty() or not query.select.empty()) ? 1 : 0;
unsigned sendWant = (want > 0) ? 1 : 0;
pk.pack(KEY_A);
pk.pack_map(2 + sendQuery + sendWant);
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_REQ_H);
pk.pack(info_hash);
if (sendQuery) {
pk.pack(KEY_Q);
pk.pack(query);
}
if (sendWant) {
pk.pack(KEY_REQ_WANT);
unsigned sendWant4 = (want & WANT4) ? 1 : 0;
unsigned sendWant6 = (want & WANT6) ? 1 : 0;
pk.pack_array(sendWant4 + sendWant6);
if (sendWant4)
pk.pack(AF_INET);
if (sendWant6)
pk.pack(AF_INET6);
}
pk.pack(KEY_Q);
pk.pack(QUERY_GET);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::GetValues,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request& req_status, ParsedMessage&& msg) { /* on done */
if (on_done) {
on_done(req_status,
{std::forward<ParsedMessage>(msg)});
}
},
std::move(on_expired));
sendRequest(req);
++out_stats.get;
return req;
}
SockAddr
deserializeIPv4(const uint8_t* ni)
{
SockAddr addr;
addr.setFamily(AF_INET);
auto& sin = addr.getIPv4();
std::memcpy(&sin.sin_addr, ni, 4);
std::memcpy(&sin.sin_port, ni + 4, 2);
return addr;
}
SockAddr
deserializeIPv6(const uint8_t* ni)
{
SockAddr addr;
addr.setFamily(AF_INET6);
auto& sin6 = addr.getIPv6();
std::memcpy(&sin6.sin6_addr, ni, 16);
std::memcpy(&sin6.sin6_port, ni + 16, 2);
return addr;
}
void
NetworkEngine::deserializeNodes(ParsedMessage& msg, const SockAddr& from)
{
if (msg.nodes4_raw.size() % NODE4_INFO_BUF_LEN != 0 || msg.nodes6_raw.size() % NODE6_INFO_BUF_LEN != 0) {
throw DhtProtocolException {DhtProtocolException::WRONG_NODE_INFO_BUF_LEN};
}
// deserialize nodes
const auto& now = scheduler.time();
const bool isPrivate = transport_ and config.transport.isPrivate();
auto listedPeer = [&](const Blob& keys, size_t count, size_t i, const InfoHash& id) -> Sp<transport::Peer> {
if (not transport_ or keys.size() != count * transport::KEY_SIZE)
return {};
transport::Key key;
std::copy_n(keys.data() + i * transport::KEY_SIZE, key.size(), key.begin());
return makePeer(id, key);
};
for (unsigned i = 0, n = msg.nodes4_raw.size() / NODE4_INFO_BUF_LEN; i < n; i++) {
const uint8_t* ni = msg.nodes4_raw.data() + i * NODE4_INFO_BUF_LEN;
const auto& ni_id = *reinterpret_cast<const InfoHash*>(ni);
if (ni_id == myid)
continue;
SockAddr addr = deserializeIPv4(ni + ni_id.size());
if (addr.isLoopback() and from.getFamily() == AF_INET) {
auto port = addr.getPort();
addr = from;
addr.setPort(port);
}
if (isMartian(addr) || isNodeBlacklisted(addr))
continue;
auto peer = listedPeer(msg.nodes4_keys, n, i, ni_id);
if (isPrivate and not peer)
continue;
msg.nodes4.emplace_back(cache.getNode(ni_id, addr, now, false));
if (peer)
attachPeer(*msg.nodes4.back(), peer);
onNewNode(msg.nodes4.back(), 0);
}
for (unsigned i = 0, n = msg.nodes6_raw.size() / NODE6_INFO_BUF_LEN; i < n; i++) {
const uint8_t* ni = msg.nodes6_raw.data() + i * NODE6_INFO_BUF_LEN;
const auto& ni_id = *reinterpret_cast<const InfoHash*>(ni);
if (ni_id == myid)
continue;
SockAddr addr = deserializeIPv6(ni + ni_id.size());
if (addr.isLoopback() and from.getFamily() == AF_INET6) {
auto port = addr.getPort();
addr = from;
addr.setPort(port);
}
if (isMartian(addr) || isNodeBlacklisted(addr))
continue;
auto peer = listedPeer(msg.nodes6_keys, n, i, ni_id);
if (isPrivate and not peer)
continue;
msg.nodes6.emplace_back(cache.getNode(ni_id, addr, now, false));
if (peer)
attachPeer(*msg.nodes6.back(), peer);
onNewNode(msg.nodes6.back(), 0);
}
}
std::vector<Blob>
NetworkEngine::packValueHeader(msgpack::sbuffer& buffer,
std::vector<Sp<Value>>::const_iterator b,
std::vector<Sp<Value>>::const_iterator e) const
{
std::vector<Blob> svals;
size_t total_size = 0;
svals.reserve(std::distance(b, e));
for (; b != e; ++b) {
svals.emplace_back(packMsg(*b));
total_size += svals.back().size();
}
msgpack::packer<msgpack::sbuffer> pk(&buffer);
pk.pack(KEY_REQ_VALUES);
pk.pack_array(svals.size());
// try to put everything in a single UDP packet
if (svals.size() < 50 && total_size < MAX_PACKET_VALUE_SIZE) {
for (const auto& b : svals)
buffer.write((const char*) b.data(), b.size());
// if (logger_)
// logger_->d("sending %lu bytes of values", total_size);
svals.clear();
} else {
for (const auto& b : svals)
pk.pack(b.size());
}
return svals;
}
void
NetworkEngine::sendValueParts(Tid tid, const std::vector<Blob>& svals, const Node& node, const SockAddr& addr)
{
const size_t fragmentSize = transport_ and node.getTransport() ? ENCRYPTED_FRAGMENT_SIZE : MTU;
msgpack::sbuffer buffer;
unsigned i = 0;
for (const auto& v : svals) {
size_t start {0}, end;
do {
end = std::min(start + fragmentSize, v.size());
buffer.clear();
msgpack::packer<msgpack::sbuffer> pk(&buffer);
pk.pack_map(3 + optionalFields(false));
packOptionalFields(pk, false);
pk.pack(KEY_Y);
pk.pack(KEY_V);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_V);
pk.pack_map(1);
pk.pack(i);
pk.pack_map(2);
pk.pack("o"sv);
pk.pack(start);
pk.pack("d"sv);
pk.pack_bin(end - start);
pk.pack_bin_body((const char*) v.data() + start, end - start);
send(node, addr, buffer.data(), buffer.size());
start = end;
} while (start != v.size());
i++;
}
}
void
NetworkEngine::sendNodesValues(const Node& node,
const SockAddr& addr,
Tid tid,
const BufferedNodes& nodes,
const std::vector<Sp<Value>>& st,
const Query& query,
const Blob& token)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(node);
pk.pack_map(4 + optionalFields(advertise));
auto packBlob = [&](std::string_view key, const Blob& b) {
if (b.empty())
return;
pk.pack(key);
pk.pack_bin(b.size());
pk.pack_bin_body((const char*) b.data(), b.size());
};
pk.pack(KEY_R);
pk.pack_map(2 + (not st.empty() ? 1 : 0) + (not nodes.nodes4.empty() ? 1 : 0) + (not nodes.nodes6.empty() ? 1 : 0)
+ (not nodes.keys4.empty() ? 1 : 0) + (not nodes.keys6.empty() ? 1 : 0) + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
insertAddr(pk, addr);
packBlob(KEY_REQ_NODES4, nodes.nodes4);
packBlob(KEY_REQ_NODES6, nodes.nodes6);
packBlob(KEY_REQ_KEYS4, nodes.keys4);
packBlob(KEY_REQ_KEYS6, nodes.keys6);
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
packToken(pk, token);
}
std::vector<Blob> svals {};
if (not st.empty()) { /* pack complete values */
if (query.select.empty()) {
svals = packValueHeader(buffer, st);
} else { /* pack fields */
auto fields = query.select.getSelection();
pk.pack(KEY_REQ_FIELDS);
pk.pack_map(2);
pk.pack("f"sv);
pk.pack(fields);
pk.pack("v"sv);
pk.pack_array(st.size() * fields.size());
for (const auto& v : st)
v->msgpack_pack_fields(fields, pk);
// DHT_LOG_DBG("sending closest nodes (%d+%d nodes.), %u value headers containing %u fields",
// nodes.size(), nodes6.size(), st.size(), fields.size());
}
}
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
// send response
send(node, addr, buffer.data(), buffer.size());
// send parts
if (not svals.empty())
sendValueParts(tid, svals, node, addr);
}
std::pair<Blob, Blob>
NetworkEngine::bufferNodes(sa_family_t af, const InfoHash& id, std::vector<Sp<Node>>& nodes)
{
std::sort(nodes.begin(), nodes.end(), [&](const Sp<Node>& a, const Sp<Node>& b) {
return id.xorCmp(a->id, b->id) < 0;
});
size_t nnode = std::min<size_t>(SEND_NODES, nodes.size());
Blob bnodes;
if (af == AF_INET) {
bnodes.resize(NODE4_INFO_BUF_LEN * nnode);
for (size_t i = 0; i < nnode; i++) {
const Node& n = *nodes[i];
const auto& sin = n.getAddr().getIPv4();
auto dest = bnodes.data() + NODE4_INFO_BUF_LEN * i;
memcpy(dest, n.id.data(), HASH_LEN);
memcpy(dest + HASH_LEN, &sin.sin_addr, sizeof(in_addr));
memcpy(dest + HASH_LEN + sizeof(in_addr), &sin.sin_port, sizeof(in_port_t));
}
} else if (af == AF_INET6) {
bnodes.resize(NODE6_INFO_BUF_LEN * nnode);
for (size_t i = 0; i < nnode; i++) {
const Node& n = *nodes[i];
const auto& sin6 = n.getAddr().getIPv6();
auto dest = bnodes.data() + NODE6_INFO_BUF_LEN * i;
memcpy(dest, n.id.data(), HASH_LEN);
memcpy(dest + HASH_LEN, &sin6.sin6_addr, sizeof(in6_addr));
memcpy(dest + HASH_LEN + sizeof(in6_addr), &sin6.sin6_port, sizeof(in_port_t));
}
} else {
return {};
}
Blob bkeys;
if (transport_) {
bool hasKey = false;
bkeys.resize(transport::KEY_SIZE * nnode);
for (size_t i = 0; i < nnode; i++) {
if (const auto& peer = nodes[i]->getTransport()) {
std::copy(peer->key.begin(), peer->key.end(), bkeys.begin() + transport::KEY_SIZE * i);
hasKey = true;
}
}
if (not hasKey)
bkeys.clear();
}
return {std::move(bnodes), std::move(bkeys)};
}
NetworkEngine::BufferedNodes
NetworkEngine::bufferNodes(
sa_family_t af, const InfoHash& id, want_t want, std::vector<Sp<Node>>& nodes4, std::vector<Sp<Node>>& nodes6)
{
if (want < 0)
want = af == AF_INET ? WANT4 : WANT6;
BufferedNodes buffered;
if (want & WANT4)
std::tie(buffered.nodes4, buffered.keys4) = bufferNodes(AF_INET, id, nodes4);
if (want & WANT6)
std::tie(buffered.nodes6, buffered.keys6) = bufferNodes(AF_INET6, id, nodes6);
return buffered;
}
Sp<Request>
NetworkEngine::sendListen(const Sp<Node>& n,
const InfoHash& hash,
const Query& query,
const Blob& token,
Tid socketId,
RequestCb&& on_done,
RequestExpiredCb&& on_expired)
{
Tid tid(n->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
auto has_query = not query.where.empty() or not query.select.empty();
pk.pack(KEY_A);
pk.pack_map(4 + has_query + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_VERSION);
pk.pack(1);
pk.pack(KEY_REQ_H);
pk.pack(hash);
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
packToken(pk, token);
}
pk.pack(KEY_REQ_SID);
pk.pack(socketId);
if (has_query) {
pk.pack(KEY_REQ_QUERY);
pk.pack(query);
}
pk.pack(KEY_Q);
pk.pack(QUERY_LISTEN);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::Listen,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request& req_status, ParsedMessage&& msg) { /* on done */
if (on_done)
on_done(req_status,
{std::forward<ParsedMessage>(msg)});
},
std::move(on_expired));
sendRequest(req);
++out_stats.listen;
return req;
}
void
NetworkEngine::sendListenConfirmation(const Node& node, const SockAddr& addr, Tid tid, const Blob& token)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(node);
pk.pack_map(4 + optionalFields(advertise));
pk.pack(KEY_R);
pk.pack_map(2 + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
insertAddr(pk, addr);
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
packToken(pk, token);
}
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
send(node, addr, buffer.data(), buffer.size());
}
Sp<Request>
NetworkEngine::sendAnnounceValue(const Sp<Node>& n,
const InfoHash& infohash,
const Sp<Value>& value,
time_point created,
const Blob& token,
RequestCb&& on_done,
RequestExpiredCb&& on_expired)
{
Tid tid(n->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
bool add_created = created < scheduler.time();
pk.pack(KEY_A);
pk.pack_map(3 + (add_created ? 1 : 0) + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_REQ_H);
pk.pack(infohash);
auto v = packValueHeader(buffer, {value});
if (add_created) {
pk.pack(KEY_REQ_CREATION);
pk.pack(to_time_t(created));
}
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
pk.pack(token);
}
pk.pack(KEY_Q);
pk.pack(QUERY_PUT);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::AnnounceValue,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[this, on_done = std::move(on_done)](const Request& req_status, ParsedMessage&& msg) {
/* on done */
if (msg.value_id == Value::INVALID_ID) {
if (logger_)
logger_->debug("[node {}] Unknown search or announce!", req_status.node->toString());
} else {
if (on_done) {
RequestAnswer answer {};
answer.vid = msg.value_id;
on_done(req_status, std::move(answer));
}
}
},
std::move(on_expired));
req->parts = std::move(v);
sendRequest(req);
++out_stats.put;
return req;
}
void
NetworkEngine::sendUpdateValues(const Sp<Node>& n,
const InfoHash& infohash,
std::vector<Sp<Value>>&& values,
time_point created,
const Blob& token,
size_t socket_id)
{
size_t total_size = 0;
auto b = values.begin(), e = values.begin();
while (e != values.end()) {
if (total_size >= MAX_MESSAGE_VALUE_SIZE) {
sendUpdateValues(n, infohash, b, e, created, token, socket_id);
b = e;
total_size = 0;
}
total_size += (*e)->size();
++e;
}
if (b != e) {
sendUpdateValues(n, infohash, b, e, created, token, socket_id);
}
}
Sp<Request>
NetworkEngine::sendUpdateValues(const Sp<Node>& n,
const InfoHash& infohash,
std::vector<Sp<Value>>::iterator begin,
std::vector<Sp<Value>>::iterator end,
time_point created,
const Blob& token,
size_t socket_id)
{
Tid tid(n->getNewTid());
Tid sid(socket_id);
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
pk.pack(KEY_A);
pk.pack_map(5 + (created < scheduler.time() ? 1 : 0) + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_VERSION);
pk.pack(1);
pk.pack(KEY_REQ_H);
pk.pack(infohash);
pk.pack(KEY_REQ_SID);
pk.pack(sid);
auto v = packValueHeader(buffer, begin, end);
if (created < scheduler.time()) {
pk.pack(KEY_REQ_CREATION);
pk.pack(to_time_t(created));
}
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
pk.pack(token);
}
pk.pack(KEY_Q);
pk.pack(QUERY_UPDATE);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::UpdateValue,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[=](const Request&, ParsedMessage&&) { /* on done */ },
[=](const Request&, bool) { /* on expired */ });
req->parts = std::move(v);
sendRequest(req);
++out_stats.updateValue;
return req;
}
Sp<Request>
NetworkEngine::sendRefreshValue(const Sp<Node>& n,
const InfoHash& infohash,
const Value::Id& vid,
const Blob& token,
RequestCb&& on_done,
RequestErrorCb&& on_error,
RequestExpiredCb&& on_expired)
{
Tid tid(n->getNewTid());
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(*n);
pk.pack_map(5 + optionalFields(advertise));
pk.pack(KEY_A);
pk.pack_map(3 + (not token.empty() ? 1 : 0));
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_REQ_H);
pk.pack(infohash);
pk.pack(KEY_REQ_VALUE_ID);
pk.pack(vid);
if (not token.empty()) {
pk.pack(KEY_REQ_TOKEN);
pk.pack(token);
}
pk.pack(KEY_Q);
pk.pack(QUERY_REFRESH);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_Q);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
auto req = std::make_shared<Request>(
MessageType::Refresh,
tid,
n,
Blob(buffer.data(), buffer.data() + buffer.size()),
[this, on_done = std::move(on_done)](const Request& req_status, ParsedMessage&& msg) {
/* on done */
if (msg.value_id == Value::INVALID_ID) {
if (logger_)
logger_->debug("[node {}] Unknown search or announce!", req_status.node->toString());
} else {
if (on_done) {
RequestAnswer answer {};
answer.vid = msg.value_id;
on_done(req_status, std::move(answer));
}
}
},
std::move(on_error),
std::move(on_expired));
sendRequest(req);
++out_stats.refresh;
return req;
}
void
NetworkEngine::sendValueAnnounced(const Node& node, const SockAddr& addr, Tid tid, Value::Id vid)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(node);
pk.pack_map(4 + optionalFields(advertise));
pk.pack(KEY_R);
pk.pack_map(3);
pk.pack(KEY_REQ_ID);
pk.pack(myid);
pk.pack(KEY_REQ_VALUE_ID);
pk.pack(vid);
insertAddr(pk, addr);
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_R);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
send(node, addr, buffer.data(), buffer.size());
}
void
NetworkEngine::sendError(
const Node& node, const SockAddr& addr, Tid tid, uint16_t code, const std::string& message, bool include_id)
{
msgpack::sbuffer buffer;
msgpack::packer<msgpack::sbuffer> pk(&buffer);
bool advertise = advertiseKey(node);
pk.pack_map(4 + (include_id ? 1 : 0) + optionalFields(advertise));
pk.pack(KEY_E);
pk.pack_array(2);
pk.pack(code);
pk.pack(message);
if (include_id) {
pk.pack(KEY_R);
pk.pack_map(1);
pk.pack(KEY_REQ_ID);
pk.pack(myid);
}
pk.pack(KEY_TID);
pk.pack(tid);
pk.pack(KEY_Y);
pk.pack(KEY_E);
pk.pack(KEY_UA);
pk.pack(OPENDHT_UA);
packOptionalFields(pk, advertise);
send(node, addr, buffer.data(), buffer.size());
}
void
NetworkEngine::maintainRxBuffer(const PartialMessageKey& key)
{
auto msg = partial_messages.find(key);
if (msg != partial_messages.end()) {
const auto& now = scheduler.time();
if (msg->second.start + RX_MAX_PACKET_TIME < now || msg->second.last_part + RX_TIMEOUT < now) {
if (logger_)
logger_->warn("Dropping expired partial message from {}", msg->second.from.toString());
partial_messages.erase(msg);
}
}
}
} /* namespace net */
} /* namespace dht */
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