bool put_data::invoke(observer_ptr o)
{
if (m_done) return false;
// TODO: what if o is not an instance of put_data_observer? This need to be
// redesigned for better type safety.
auto* po = static_cast<put_data_observer*>(o.get());
entry e;
e["y"] = "q";
e["q"] = "put";
entry& a = e["a"];
a["v"] = m_data.value();
a["token"] = po->m_token;
if (m_data.is_mutable())
{
a["k"] = m_data.pk().bytes;
a["seq"] = m_data.seq().value;
a["sig"] = m_data.sig().bytes;
if (!m_data.salt().empty())
{
a["salt"] = m_data.salt();
}
}
m_node.stats_counters().inc_stats_counter(counters::dht_put_out);
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool get_peers::invoke(observer_ptr o)
{
if (m_done)
{
m_invoke_count = -1;
return false;
}
entry e;
e["y"] = "q";
entry& a = e["a"];
e["q"] = "get_peers";
a["info_hash"] = m_target.to_string();
if (m_noseeds) a["noseed"] = 1;
if (m_node.observer())
{
m_node.observer()->outgoing_get_peers(m_target, m_target, o->target_ep());
}
m_node.stats_counters().inc_stats_counter(counters::dht_get_peers_out);
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool put_data::invoke(observer_ptr o)
{
if (m_done)
{
m_invoke_count = -1;
return false;
}
// TODO: what if o is not an isntance of put_data_observer? This need to be
// redesigned for better type saftey.
put_data_observer* po = static_cast<put_data_observer*>(o.get());
entry e;
e["y"] = "q";
e["q"] = "put";
entry& a = e["a"];
a["v"] = m_data.value();
a["token"] = po->m_token;
if (m_data.is_mutable())
{
a["k"] = std::string(m_data.pk().data(), item_pk_len);
a["seq"] = m_data.seq();
a["sig"] = std::string(m_data.sig().data(), item_sig_len);
if (!m_data.salt().empty())
{
a["salt"] = m_data.salt();
}
}
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool obfuscated_get_peers::invoke(observer_ptr o)
{
if (!m_obfuscated) return get_peers::invoke(o);
const node_id id = o->id();
const int shared_prefix = 160 - distance_exp(id, m_target);
// when we get close to the target zone in the DHT
// start using the correct info-hash, in order to
// start receiving peers
if (shared_prefix > m_node.m_table.depth() - 4)
{
m_obfuscated = false;
// clear the queried bits on all successful nodes in
// our node-list for this traversal algorithm, to
// allow the get_peers traversal to regress in case
// nodes further down end up being dead
for (std::vector<observer_ptr>::iterator i = m_results.begin()
, end(m_results.end()); i != end; ++i)
{
observer* const node = i->get();
// don't re-request from nodes that didn't respond
if (node->flags & observer::flag_failed) continue;
// don't interrupt with queries that are already in-flight
if ((node->flags & observer::flag_alive) == 0) continue;
node->flags &= ~(observer::flag_queried | observer::flag_alive);
}
return get_peers::invoke(o);
}
entry e;
e["y"] = "q";
e["q"] = "get_peers";
entry& a = e["a"];
// This logic will obfuscate the target info-hash
// we're looking up, in order to preserve more privacy
// on the DHT. This is done by only including enough
// bits in the info-hash for the node we're querying to
// give a good answer, but not more.
// now, obfuscate the bits past shared_prefix + 3
node_id mask = generate_prefix_mask(shared_prefix + 3);
node_id obfuscated_target = generate_random_id() & ~mask;
obfuscated_target |= m_target & mask;
a["info_hash"] = obfuscated_target.to_string();
if (m_node.observer())
{
m_node.observer()->outgoing_get_peers(m_target, obfuscated_target
, o->target_ep());
}
m_node.stats_counters().inc_stats_counter(counters::dht_get_peers_out);
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
void rpc_manager::invoke(int message_id, udp::endpoint target_addr
, observer_ptr o)
{
INVARIANT_CHECK;
if (m_destructing)
{
o->abort();
return;
}
msg m;
m.message_id = message_id;
m.reply = false;
m.id = m_our_id;
m.addr = target_addr;
TORRENT_ASSERT(!m_transactions[m_next_transaction_id]);
#ifdef TORRENT_DEBUG
int potential_new_id = m_next_transaction_id;
#endif
#ifndef BOOST_NO_EXCEPTIONS
try
{
#endif
m.transaction_id.clear();
std::back_insert_iterator<std::string> out(m.transaction_id);
io::write_uint16(m_next_transaction_id, out);
o->send(m);
o->sent = time_now();
#if TORRENT_USE_IPV6
o->target_addr = target_addr.address();
#else
o->target_addr = target_addr.address().to_v4();
#endif
o->port = target_addr.port();
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(rpc) << "Invoking " << messages::ids[message_id]
<< " -> " << target_addr;
#endif
m_send(m);
new_transaction_id(o);
#ifndef BOOST_NO_EXCEPTIONS
}
catch (std::exception& e)
{
// m_send may fail with "no route to host"
TORRENT_ASSERT(potential_new_id == m_next_transaction_id);
o->abort();
}
#endif
}
// returns true of lhs and rhs are too close to each other to appear
// in the same DHT search under different node IDs
bool compare_ip_cidr(observer_ptr const& lhs, observer_ptr const& rhs)
{
if (lhs->target_addr().is_v4() != rhs->target_addr().is_v4())
return false;
// the number of bits in the IPs that may match. If
// more bits that this matches, something suspicious is
// going on and we shouldn't add the second one to our
// routing table
int cutoff = rhs->target_addr().is_v4() ? 4 : 64;
int dist = cidr_distance(lhs->target_addr(), rhs->target_addr());
return dist <= cutoff;
}
// prevent request means that the total number of requests has
// overflown. This query failed because it was the oldest one.
// So, if this is true, don't make another request
void traversal_algorithm::failed(observer_ptr o, int flags)
{
TORRENT_ASSERT(m_invoke_count >= 0);
if (m_results.empty()) return;
TORRENT_ASSERT(o->flags & observer::flag_queried);
if (flags & short_timeout)
{
// short timeout means that it has been more than
// two seconds since we sent the request, and that
// we'll most likely not get a response. But, in case
// we do get a late response, keep the handler
// around for some more, but open up the slot
// by increasing the branch factor
if ((o->flags & observer::flag_short_timeout) == 0)
++m_branch_factor;
o->flags |= observer::flag_short_timeout;
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(traversal) << "[" << this << "] 1ST_TIMEOUT "
<< " id: " << o->id()
<< " distance: " << distance_exp(m_target, o->id())
<< " addr: " << o->target_ep()
<< " branch-factor: " << m_branch_factor
<< " invoke-count: " << m_invoke_count;
#endif
}
else
{
o->flags |= observer::flag_failed;
// if this flag is set, it means we increased the
// branch factor for it, and we should restore it
if (o->flags & observer::flag_short_timeout)
--m_branch_factor;
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(traversal) << "[" << this << "] TIMEOUT "
<< " id: " << o->id()
<< " distance: " << distance_exp(m_target, o->id())
<< " addr: " << o->target_ep()
<< " branch-factor: " << m_branch_factor
<< " invoke-count: " << m_invoke_count;
#endif
// don't tell the routing table about
// node ids that we just generated ourself
if ((o->flags & observer::flag_no_id) == 0)
m_node.m_table.node_failed(o->id(), o->target_ep());
++m_timeouts;
--m_invoke_count;
TORRENT_ASSERT(m_invoke_count >= 0);
}
if (flags & prevent_request)
{
--m_branch_factor;
if (m_branch_factor <= 0) m_branch_factor = 1;
}
bool is_done = add_requests();
if (is_done) done();
}
unsigned int rpc_manager::new_transaction_id(observer_ptr o)
{
INVARIANT_CHECK;
unsigned int tid = m_next_transaction_id;
m_next_transaction_id = (m_next_transaction_id + 1) % max_transactions;
if (m_transactions[m_next_transaction_id])
{
// moving the observer into the set of aborted transactions
// it will prevent it from spawning new requests right now,
// since that would break the invariant
observer_ptr o = m_transactions[m_next_transaction_id];
m_aborted_transactions.push_back(o);
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(rpc) << "[new_transaction_id] Aborting message with transaction id: "
<< m_next_transaction_id << " sent to " << o->target_ep()
<< " " << total_seconds(time_now() - o->sent) << " seconds ago";
#endif
m_transactions[m_next_transaction_id] = 0;
TORRENT_ASSERT(m_oldest_transaction_id == m_next_transaction_id);
}
TORRENT_ASSERT(!m_transactions[tid]);
m_transactions[tid] = o;
if (m_oldest_transaction_id == m_next_transaction_id)
{
m_oldest_transaction_id = (m_oldest_transaction_id + 1) % max_transactions;
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(rpc) << "WARNING: transaction limit reached! Too many concurrent"
" messages! limit: " << (int)max_transactions;
#endif
update_oldest_transaction_id();
}
return tid;
}
bool find_data::invoke(observer_ptr o)
{
if (m_done)
{
m_invoke_count = -1;
return false;
}
// send request to find closer nodes
kademlia2_req req;
req.kid_receiver = o->id();
req.kid_target = m_target;
req.search_type = m_search_type;
o->m_packet_id = m_target; // bind observer to correspond packet
return m_node.m_rpc.invoke(req, o->target_ep(), o);
}
bool rpc_manager::invoke(entry& e, udp::endpoint target_addr
, observer_ptr o)
{
INVARIANT_CHECK;
if (m_destructing) return false;
e["y"] = "q";
entry& a = e["a"];
add_our_id(a);
std::string transaction_id;
transaction_id.resize(2);
char* out = &transaction_id[0];
int tid = (random() ^ (random() << 5)) & 0xffff;
io::write_uint16(tid, out);
e["t"] = transaction_id;
// When a DHT node enters the read-only state, in each outgoing query message,
// places a 'ro' key in the top-level message dictionary and sets its value to 1.
if (m_settings.read_only) e["ro"] = 1;
node& n = o->algorithm()->get_node();
if (!n.native_address(o->target_addr()))
{
a["want"].list().push_back(entry(n.protocol_family_name()));
}
o->set_target(target_addr);
o->set_transaction_id(tid);
#ifndef TORRENT_DISABLE_LOGGING
m_log->log(dht_logger::rpc_manager, "[%p] invoking %s -> %s"
, static_cast<void*>(o->algorithm()), e["q"].string().c_str()
, print_endpoint(target_addr).c_str());
#endif
if (m_sock->send_packet(e, target_addr))
{
m_transactions.insert(std::make_pair(tid, o));
#if TORRENT_USE_ASSERTS
o->m_was_sent = true;
#endif
return true;
}
return false;
}
bool refresh::invoke(observer_ptr o)
{
entry e;
e["z"] = "q";
e["q"] = "findNode";
entry& a = e["x"];
a["target"] = target().to_string();
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool rpc_manager::invoke(entry& e, udp::endpoint target_addr
, observer_ptr o)
{
INVARIANT_CHECK;
if (m_destructing) return false;
e["y"] = "q";
entry& a = e["a"];
add_our_id(a);
std::string transaction_id;
transaction_id.resize(2);
char* out = &transaction_id[0];
int tid = (random() ^ (random() << 5)) & 0xffff;
io::write_uint16(tid, out);
e["t"] = transaction_id;
o->set_target(target_addr);
o->set_transaction_id(tid);
#ifndef TORRENT_DISABLE_LOGGING
m_log->log(dht_logger::rpc_manager, "[%p] invoking %s -> %s"
, static_cast<void*>(o->algorithm()), e["q"].string().c_str()
, print_endpoint(target_addr).c_str());
#endif
if (m_sock->send_packet(e, target_addr, 1))
{
m_transactions.insert(std::make_pair(tid,o));
#if TORRENT_USE_ASSERTS
o->m_was_sent = true;
#endif
return true;
}
return false;
}
bool get_item::invoke(observer_ptr o)
{
if (m_done) return false;
entry e;
e["y"] = "q";
entry& a = e["a"];
e["q"] = "get";
a["target"] = target().to_string();
m_node.stats_counters().inc_stats_counter(counters::dht_get_out);
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool rpc_manager::invoke(entry& e, udp::endpoint target_addr
, observer_ptr o)
{
INVARIANT_CHECK;
if (m_destructing) return false;
e["y"] = "q";
entry& a = e["a"];
add_our_id(a);
std::string transaction_id;
transaction_id.resize(2);
char* out = &transaction_id[0];
int tid = (random() ^ (random() << 5)) & 0xffff;
io::write_uint16(tid, out);
e["t"] = transaction_id;
o->set_target(target_addr);
o->set_transaction_id(tid);
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(rpc) << "[" << o->m_algorithm.get() << "] invoking "
<< e["q"].string() << " -> " << target_addr;
#endif
if (m_sock->send_packet(e, target_addr, 1))
{
m_transactions.insert(std::make_pair(tid,o));
#if TORRENT_USE_ASSERTS
o->m_was_sent = true;
#endif
return true;
}
return false;
}
bool rpc_manager::invoke(entry& e, udp::endpoint target_addr
, observer_ptr o)
{
INVARIANT_CHECK;
if (m_destructing) return false;
e["y"] = "q";
entry& a = e["a"];
add_our_id(a);
std::string transaction_id;
transaction_id.resize(2);
char* out = &transaction_id[0];
int tid = rand() ^ (rand() << 5);
io::write_uint16(tid, out);
e["t"] = transaction_id;
o->set_target(target_addr);
o->set_transaction_id(tid);
#ifdef TORRENT_DHT_VERBOSE_LOGGING
TORRENT_LOG(rpc) << "[" << o->m_algorithm.get() << "] invoking "
<< e["q"].string() << " -> " << target_addr;
#endif
if (m_send(m_userdata, e, target_addr, 1))
{
m_transactions.push_back(o);
#if defined TORRENT_DEBUG || TORRENT_RELEASE_ASSERTS
o->m_was_sent = true;
#endif
return true;
}
return false;
}
bool find_data::invoke(observer_ptr o)
{
if (m_done)
{
m_invoke_count = -1;
return false;
}
entry e;
e["y"] = "q";
e["q"] = "get_peers";
entry& a = e["a"];
a["info_hash"] = m_target.to_string();
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
bool find_data::invoke(observer_ptr o)
{
if (m_done)
{
m_invoke_count = -1;
return false;
}
entry e;
e["h"] = "q";
e["q"] = "getData"; // "getPeers"
entry& a = e["g"];
entry& target = a["target"];
target["n"] = m_trackerName;
target["r"] = "tracker";
target["t"] = "m";
a["infoHash"] = m_target.to_string();
if (m_noseeds) a["noseed"] = 1;
return m_node.m_rpc.invoke(e, o->target_ep(), o);
}
// prevent request means that the total number of requests has
// overflown. This query failed because it was the oldest one.
// So, if this is true, don't make another request
void traversal_algorithm::failed(observer_ptr o, int const flags)
{
// don't tell the routing table about
// node ids that we just generated ourself
if ((o->flags & observer::flag_no_id) == 0)
m_node.m_table.node_failed(o->id(), o->target_ep());
if (m_results.empty()) return;
bool decrement_branch_factor = false;
TORRENT_ASSERT(o->flags & observer::flag_queried);
if (flags & short_timeout)
{
// short timeout means that it has been more than
// two seconds since we sent the request, and that
// we'll most likely not get a response. But, in case
// we do get a late response, keep the handler
// around for some more, but open up the slot
// by increasing the branch factor
if ((o->flags & observer::flag_short_timeout) == 0)
{
TORRENT_ASSERT(m_branch_factor < (std::numeric_limits<std::int16_t>::max)());
++m_branch_factor;
}
o->flags |= observer::flag_short_timeout;
#ifndef TORRENT_DISABLE_LOGGING
dht_observer* logger = get_node().observer();
if (logger != nullptr && logger->should_log(dht_logger::traversal))
{
char hex_id[41];
aux::to_hex(o->id(), hex_id);
logger->log(dht_logger::traversal
, "[%p] 1ST_TIMEOUT id: %s distance: %d addr: %s branch-factor: %d "
"invoke-count: %d type: %s"
, static_cast<void*>(this), hex_id, distance_exp(m_target, o->id())
, print_address(o->target_addr()).c_str(), m_branch_factor
, m_invoke_count, name());
}
#endif
}
else
{
o->flags |= observer::flag_failed;
// if this flag is set, it means we increased the
// branch factor for it, and we should restore it
decrement_branch_factor = (o->flags & observer::flag_short_timeout) != 0;
#ifndef TORRENT_DISABLE_LOGGING
dht_observer* logger = get_node().observer();
if (logger != nullptr && logger->should_log(dht_logger::traversal))
{
char hex_id[41];
aux::to_hex(o->id(), hex_id);
logger->log(dht_logger::traversal
, "[%p] TIMEOUT id: %s distance: %d addr: %s branch-factor: %d "
"invoke-count: %d type: %s"
, static_cast<void*>(this), hex_id, distance_exp(m_target, o->id())
, print_address(o->target_addr()).c_str(), m_branch_factor
, m_invoke_count, name());
}
#endif
++m_timeouts;
TORRENT_ASSERT(m_invoke_count > 0);
--m_invoke_count;
}
// this is another reason to decrement the branch factor, to prevent another
// request from filling this slot. Only ever decrement once per response though
decrement_branch_factor |= (flags & prevent_request);
if (decrement_branch_factor)
{
TORRENT_ASSERT(m_branch_factor > 0);
--m_branch_factor;
if (m_branch_factor <= 0) m_branch_factor = 1;
}
bool const is_done = add_requests();
if (is_done) done();
}
