merged DHT change from RC_0_16

docs/dht_sec.rst

@@ -137,15 +137,21 @@ bootstrapping
 -------------
 
 In order to set ones initial node ID, the external IP needs to be known. This
-is not a trivial problem. With this extension, *all* DHT requests whose node
+is not a trivial problem. With this extension, *all* DHT responses SHOULD include
-ID does not match its IP address MUST be serviced and MUST also include one
+a *top-level* field called ``ip``, containing a compact binary representation of
-extra result value (inside the ``r`` dictionary) called ``ip``. The IP field
+the requestor's IP and port. That is big endian IP followed by 2 bytes of big endian
-contains the raw (big endian) byte representation of the external IP address.
+port.
-This is the same byte sequence used to verify the node ID.
+
+The IP portion is the same byte sequence used to verify the node ID.
+
+It is important that the ``ip`` field is in the top level dictionary. Nodes that
+enforce the node-ID will respond with an error message ("y": "e", "e": { ... }),
+whereas a node that supports this extension but without enforcing it will respond
+with a normal reply ("y": "r", "r": { ... }).
 
 A DHT node which receives an ``ip`` result in a request SHOULD consider restarting
 its DHT node with a new node ID, taking this IP into account. Since a single node
-can not be trusted, there should be some mechanism of determining whether or
+can not be trusted, there should be some mechanism to determine whether or
 not the node has a correct understanding of its external IP or not. This could
 be done by voting, or only restart the DHT once at least a certain number of
 nodes, from separate searches, tells you your node ID is incorrect.

include/libtorrent/kademlia/node.hpp

@@ -68,6 +68,7 @@ TORRENT_DECLARE_LOG(node);
 #endif
 
 struct traversal_algorithm;
+struct dht_observer;
 
 struct key_desc_t
 {
@@ -295,6 +296,8 @@ public:
 	rpc_manager m_rpc;
 
 private:
+	dht_observer* m_observer;
+
 	table_t m_map;
 	dht_immutable_table_t m_immutable_table;
 	dht_mutable_table_t m_mutable_table;

include/libtorrent/kademlia/rpc_manager.hpp

@@ -66,16 +66,13 @@ struct null_observer : public observer
 };
 
 class routing_table;
-struct dht_observer;
 
 class TORRENT_EXTRA_EXPORT rpc_manager
 {
 public:
-	typedef boost::function3<void, address, int, address> external_ip_fun;
 
 	rpc_manager(node_id const& our_id
-		, routing_table& table, udp_socket_interface* sock
+		, routing_table& table, udp_socket_interface* sock);
-		, dht_observer* observer);
 	~rpc_manager();
 
 	void unreachable(udp::endpoint const& ep);
@@ -118,7 +115,6 @@ private:
 	node_id m_random_number;
 	int m_allocated_observers;
 	bool m_destructing;
-	dht_observer* m_observer;
 };
 
 } } // namespace libtorrent::dht

include/libtorrent/socket_io.hpp

@@ -47,6 +47,7 @@ namespace libtorrent
 	TORRENT_EXTRA_EXPORT std::string print_endpoint(tcp::endpoint const& ep);
 	TORRENT_EXTRA_EXPORT std::string print_endpoint(udp::endpoint const& ep);
 	TORRENT_EXTRA_EXPORT std::string address_to_bytes(address const& a);
+	TORRENT_EXPORT std::string endpoint_to_bytes(udp::endpoint const& ep);
 	TORRENT_EXTRA_EXPORT void hash_address(address const& ip, sha1_hash& h);
 
 	namespace detail

src/kademlia/node.cpp

@@ -48,6 +48,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/kademlia/rpc_manager.hpp"
 #include "libtorrent/kademlia/routing_table.hpp"
 #include "libtorrent/kademlia/node.hpp"
+#include <libtorrent/kademlia/dht_observer.hpp>
 
 #include "libtorrent/kademlia/refresh.hpp"
 #include "libtorrent/kademlia/find_data.hpp"
@@ -100,7 +101,8 @@ node_impl::node_impl(alert_dispatcher* alert_disp
 	: m_settings(settings)
 	, m_id(nid == (node_id::min)() || !verify_id(nid, external_address) ? generate_id(external_address) : nid)
 	, m_table(m_id, 8, settings)
-	, m_rpc(m_id, m_table, sock, observer)
+	, m_rpc(m_id, m_table, sock)
+	, m_observer(observer)
 	, m_last_tracker_tick(time_now())
 	, m_post_alert(alert_disp)
 	, m_sock(sock)
@@ -221,6 +223,28 @@ void node_impl::incoming(msg const& m)
 
 	char y = *(y_ent->string_ptr());
 
+	lazy_entry const* ext_ip = m.message.dict_find_string("ip");
+	if (ext_ip && ext_ip->string_length() == 4)
+	{
+		// this node claims we use the wrong node-ID!
+		address_v4::bytes_type b;
+		memcpy(&b[0], ext_ip->string_ptr(), 4);
+		if (m_observer)
+			m_observer->set_external_address(address_v4(b)
+				, m.addr.address());
+	}
+#if TORRENT_USE_IPV6
+	else if (ext_ip && ext_ip->string_length() == 16)
+	{
+		// this node claims we use the wrong node-ID!
+		address_v6::bytes_type b;
+		memcpy(&b[0], ext_ip->string_ptr(), 16);
+		if (m_observer)
+			m_observer->set_external_address(address_v6(b)
+				, m.addr.address());
+	}
+#endif
+
 	switch (y)
 	{
 		case 'r':
@@ -657,6 +681,17 @@ void node_impl::incoming_request(msg const& m, entry& e)
 		return;
 	}
 
+	e["ip"] = endpoint_to_bytes(m.addr);
+/*
+	// if this nodes ID doesn't match its IP, tell it what
+	// its IP is with an error
+	// don't enforce this yet
+	if (!verify_id(id, m.addr.address()))
+	{
+		incoming_error(e, "invalid node ID");
+		return;
+	}
+*/
 	char const* query = top_level[0]->string_cstr();
 
 	lazy_entry const* arg_ent = top_level[1];
@@ -668,11 +703,6 @@ void node_impl::incoming_request(msg const& m, entry& e)
 	entry& reply = e["r"];
 	m_rpc.add_our_id(reply);
 
-	// if this nodes ID doesn't match its IP, tell it what
-	// its IP is
-	if (!verify_id(id, m.addr.address()))
-		reply["ip"] = address_to_bytes(m.addr.address());
-
 	// mirror back the other node's external port
 	reply["p"] = m.addr.port();
 

src/kademlia/rpc_manager.cpp

@@ -46,7 +46,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/kademlia/refresh.hpp>
 #include <libtorrent/kademlia/node.hpp>
 #include <libtorrent/kademlia/observer.hpp>
-#include <libtorrent/kademlia/dht_observer.hpp>
 #include <libtorrent/hasher.hpp>
 #include <libtorrent/time.hpp>
 #include <time.h> // time()
@@ -159,8 +158,7 @@ enum { observer_size = max3<
 };
 
 rpc_manager::rpc_manager(node_id const& our_id
-	, routing_table& table, udp_socket_interface* sock
+	, routing_table& table, udp_socket_interface* sock)
-	, dht_observer* observer)
 	: m_pool_allocator(observer_size, 10)
 	, m_sock(sock)
 	, m_our_id(our_id)
@@ -169,7 +167,6 @@ rpc_manager::rpc_manager(node_id const& our_id
 	, m_random_number(generate_random_id())
 	, m_allocated_observers(0)
 	, m_destructing(false)
-	, m_observer(observer)
 {
 	std::srand(time(0));
 
@@ -340,28 +337,6 @@ bool rpc_manager::incoming(msg const& m, node_id* id)
 		return false;
 	}
 
-	lazy_entry const* ext_ip = ret_ent->dict_find_string("ip");
-	if (ext_ip && ext_ip->string_length() == 4)
-	{
-		// this node claims we use the wrong node-ID!
-		address_v4::bytes_type b;
-		memcpy(&b[0], ext_ip->string_ptr(), 4);
-		if (m_observer)
-			m_observer->set_external_address(address_v4(b)
-				, m.addr.address());
-	}
-#if TORRENT_USE_IPV6
-	else if (ext_ip && ext_ip->string_length() == 16)
-	{
-		// this node claims we use the wrong node-ID!
-		address_v6::bytes_type b;
-		memcpy(&b[0], ext_ip->string_ptr(), 16);
-		if (m_observer)
-			m_observer->set_external_address(address_v6(b)
-				, m.addr.address());
-	}
-#endif
-
 #ifdef TORRENT_DHT_VERBOSE_LOGGING
 	TORRENT_LOG(rpc) << "[" << o->m_algorithm.get() << "] Reply with transaction id: " 
 		<< tid << " from " << m.addr;

src/socket_io.cpp

@@ -37,6 +37,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/socket.hpp"
 #include "libtorrent/socket_io.hpp"
 #include "libtorrent/address.hpp"
+#include "libtorrent/io.hpp" // for write_uint16
 #include "libtorrent/hasher.hpp" // for hasher
 
 namespace libtorrent
@@ -50,18 +51,18 @@ namespace libtorrent
 
 	std::string address_to_bytes(address const& a)
 	{
-#if TORRENT_USE_IPV6
+		std::string ret;
-		if (a.is_v6())
+		std::back_insert_iterator<std::string> out(ret);
-		{
+		detail::write_address(a, out);
-			address_v6::bytes_type b = a.to_v6().to_bytes();
+		return ret;
-			return std::string((char*)&b[0], b.size());
+	}
-		}
+
-		else
+	std::string endpoint_to_bytes(udp::endpoint const& ep)
-#endif
+	{
-		{
+		std::string ret;
-			address_v4::bytes_type b = a.to_v4().to_bytes();
+		std::back_insert_iterator<std::string> out(ret);
-			return std::string((char*)&b[0], b.size());
+		detail::write_endpoint(ep, out);
-		}
+		return ret;
 	}
 
 	std::string print_endpoint(tcp::endpoint const& ep)

test/test_primitives.cpp

@@ -48,6 +48,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/bloom_filter.hpp"
 #include "libtorrent/aux_/session_impl.hpp"
 #include "libtorrent/ip_voter.hpp"
+#include "libtorrent/socket_io.hpp"
 #include <boost/bind.hpp>
 #include <iostream>
 #include <set>
@@ -402,6 +403,14 @@ int test_main()
 	test1.resize(100, true);
 	TEST_CHECK(test1.all_set() == true);
 
+
+	// test address_to_bytes
+	TEST_EQUAL(address_to_bytes(address_v4::from_string("10.11.12.13")), "\x0a\x0b\x0c\x0d");
+	TEST_EQUAL(address_to_bytes(address_v4::from_string("16.5.127.1")), "\x10\x05\x7f\x01");
+
+	// test endpoint_to_bytes
+	TEST_EQUAL(endpoint_to_bytes(udp::endpoint(address_v4::from_string("10.11.12.13"), 8080)), "\x0a\x0b\x0c\x0d\x1f\x90");
+	TEST_EQUAL(endpoint_to_bytes(udp::endpoint(address_v4::from_string("16.5.127.1"), 12345)), "\x10\x05\x7f\x01\x30\x39");
 	return 0;
 }