premiere-libtorrent/test/test_peer_list.cpp

/*

Copyright (c) 2013, Arvid Norberg
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in
      the documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

*/

#include "libtorrent/peer_list.hpp"
#include "libtorrent/torrent_handle.hpp"
#include "libtorrent/torrent_peer_allocator.hpp"
#include "libtorrent/peer_connection_interface.hpp"
#include "libtorrent/stat.hpp"
#include "libtorrent/ip_voter.hpp"
#include "libtorrent/ip_filter.hpp"
#include "libtorrent/peer_info.hpp"
#include "libtorrent/random.hpp"

#include "test.hpp"
#include "setup_transfer.hpp"
#include <vector>
#include <stdarg.h>

using namespace libtorrent;

tcp::endpoint ep(char const* ip, int port)
{
	return tcp::endpoint(address_v4::from_string(ip), port);
}

struct mock_torrent;

struct mock_peer_connection : peer_connection_interface
	, boost::enable_shared_from_this<mock_peer_connection>
{
	mock_peer_connection(mock_torrent* tor, bool out, tcp::endpoint const& remote)
		: m_choked(false)
		, m_outgoing(out)
		, m_tp(NULL)
		, m_remote(remote)
		, m_local(ep("127.0.0.1", 8080))
		, m_disconnect_called(false)
		, m_torrent(*tor)
	{
		for (int i = 0; i < 20; ++i) m_id[i] = rand();
	}

	virtual ~mock_peer_connection() {}

#if !defined TORRENT_DISABLE_LOGGING
	virtual void peer_log(char const* fmt, ...) const
	{
		va_list v;	
		va_start(v, fmt);
		vprintf(fmt, v);
		va_end(v);
	}
#endif

	bool was_disconnected() const { return m_disconnect_called; }
	void set_local_ep(tcp::endpoint const& ep) { m_local = ep; }

	libtorrent::stat m_stat;
	bool m_choked;
	bool m_outgoing;
	torrent_peer* m_tp;
	tcp::endpoint m_remote;
	tcp::endpoint m_local;
	peer_id m_id;
	bool m_disconnect_called;
	mock_torrent& m_torrent;

	virtual void get_peer_info(peer_info& p) const {}
	virtual tcp::endpoint const& remote() const { return m_remote; }
	virtual tcp::endpoint local_endpoint() const { return m_local; }
	virtual void disconnect(error_code const& ec
		, operation_t op, int error = 0);
	virtual peer_id const& pid() const { return m_id; }
	virtual void set_holepunch_mode() {}
	virtual torrent_peer* peer_info_struct() const { return m_tp; }
	virtual void set_peer_info(torrent_peer* pi) { m_tp = pi; }
	virtual bool is_outgoing() const { return m_outgoing; }
	virtual void add_stat(boost::int64_t downloaded, boost::int64_t uploaded)
	{ m_stat.add_stat(downloaded, uploaded); }
	virtual bool fast_reconnect() const { return true; }
	virtual bool is_choked() const { return m_choked; }
	virtual bool failed() const { return false; }
	virtual libtorrent::stat const& statistics() const { return m_stat; }
};

struct mock_torrent
{
	mock_torrent(torrent_state* st) : m_p(NULL), m_state(st) {}
	virtual ~mock_torrent() {}

	bool connect_to_peer(torrent_peer* peerinfo, bool ignore_limit = false)
	{
		TORRENT_ASSERT(peerinfo->connection == NULL);
		if (peerinfo->connection) return false;
		boost::shared_ptr<mock_peer_connection> c
			= boost::make_shared<mock_peer_connection>(this, true, peerinfo->ip());
		c->set_peer_info(peerinfo);

		m_connections.push_back(c);
		m_p->set_connection(peerinfo, c.get());
		return true;
	}

#ifndef TORRENT_DISABLE_LOGGING
	void debug_log(const char* fmt, ...) const
	{
		va_list v;
		va_start(v, fmt);
		vprintf(fmt, v);
		va_end(v);
	}
#endif

	peer_list* m_p;
	torrent_state* m_state;
	std::vector<boost::shared_ptr<mock_peer_connection> > m_connections;
};

void mock_peer_connection::disconnect(error_code const& ec
	, operation_t op, int error)
{
	m_torrent.m_p->connection_closed(*this, 0, m_torrent.m_state);
	std::vector<boost::shared_ptr<mock_peer_connection> >::iterator i
		= std::find(m_torrent.m_connections.begin(), m_torrent.m_connections.end()
			, shared_from_this());
	if (i != m_torrent.m_connections.end()) m_torrent.m_connections.erase(i);

	m_tp = 0;
	m_disconnect_called = true;
}

bool has_peer(peer_list const& p, tcp::endpoint const& ep)
{
	std::pair<peer_list::const_iterator, peer_list::const_iterator> its
		= p.find_peers(ep.address());
	return its.first != its.second;
}

torrent_state init_state(torrent_peer_allocator& allocator
	, external_ip& ext_ip)
{
	torrent_state st;
	st.is_finished = false;
	st.is_paused = false;
	st.max_peerlist_size = 1000;
	st.allow_multiple_connections_per_ip = false;
	st.peer_allocator = &allocator;
	st.ip = &ext_ip;
	st.port = 9999;
	return st;
}

torrent_peer* add_peer(peer_list& p, torrent_state& st, tcp::endpoint const& ep)
{
	int cc = p.num_connect_candidates();
	torrent_peer* peer = p.add_peer(ep, 0, 0, &st);
	if (peer)
	{
		TEST_EQUAL(p.num_connect_candidates(), cc + 1);
		TEST_EQUAL(peer->port, ep.port());
	}
	st.erased.clear();
	return peer;
}

void connect_peer(peer_list& p, mock_torrent& t, torrent_state& st)
{
	torrent_peer* tp = p.connect_one_peer(0, &st);
	TEST_CHECK(tp);
	if (!tp) return;
	t.connect_to_peer(tp);
	st.erased.clear();
	TEST_CHECK(tp->connection);
}

int test_main()
{
	torrent_peer_allocator allocator;
	external_ip ext_ip;

	// test multiple peers with the same IP
	// when disallowing it
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;
		TEST_EQUAL(p.num_connect_candidates(), 0);
		torrent_peer* peer1 = p.add_peer(ep("10.0.0.2", 3000), 0, 0, &st);

		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		st.erased.clear();

		torrent_peer* peer2 = p.add_peer(ep("10.0.0.2", 9020), 0, 0, &st);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(peer1, peer2);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		st.erased.clear();
	}

	// test multiple peers with the same IP
	// when allowing it
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = true;
		peer_list p;
		t.m_p = &p;
		torrent_peer* peer1 = p.add_peer(ep("10.0.0.2", 3000), 0, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		TEST_EQUAL(p.num_peers(), 1);
		st.erased.clear();

		torrent_peer* peer2 = p.add_peer(ep("10.0.0.2", 9020), 0, 0, &st);
		TEST_EQUAL(p.num_peers(), 2);
		TEST_CHECK(peer1 != peer2);
		TEST_EQUAL(p.num_connect_candidates(), 2);
		st.erased.clear();
	}

	// test adding two peers with the same IP, but different ports, to
	// make sure they can be connected at the same time
	// with allow_multiple_connections_per_ip enabled
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = true;
		peer_list p;
		t.m_p = &p;
		torrent_peer* peer1 = p.add_peer(ep("10.0.0.2", 3000), 0, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		st.erased.clear();

		TEST_EQUAL(p.num_peers(), 1);
		torrent_peer* tp = p.connect_one_peer(0, &st);
		TEST_CHECK(tp);
		t.connect_to_peer(tp);
		st.erased.clear();

		// we only have one peer, we can't
		// connect another one
		tp = p.connect_one_peer(0, &st);
		TEST_CHECK(tp == NULL);
		st.erased.clear();
	
		torrent_peer* peer2 = p.add_peer(ep("10.0.0.2", 9020), 0, 0, &st);
		TEST_EQUAL(p.num_peers(), 2);
		TEST_CHECK(peer1 != peer2);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		st.erased.clear();

		tp = p.connect_one_peer(0, &st);
		TEST_CHECK(tp);
		t.connect_to_peer(tp);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		st.erased.clear();
	}

	// test adding two peers with the same IP, but different ports, to
	// make sure they can not be connected at the same time
	// with allow_multiple_connections_per_ip disabled
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;
		torrent_peer* peer1 = p.add_peer(ep("10.0.0.2", 3000), 0, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		TEST_EQUAL(peer1->port, 3000);
		st.erased.clear();

		TEST_EQUAL(p.num_peers(), 1);
		torrent_peer* tp = p.connect_one_peer(0, &st);
		TEST_CHECK(tp);
		t.connect_to_peer(tp);
		st.erased.clear();

		// we only have one peer, we can't
		// connect another one
		tp = p.connect_one_peer(0, &st);
		TEST_CHECK(tp == NULL);
		st.erased.clear();
	
		torrent_peer* peer2 = p.add_peer(ep("10.0.0.2", 9020), 0, 0, &st);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(peer2->port, 9020);
		TEST_CHECK(peer1 == peer2);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		st.erased.clear();
	}

	// test incoming connection
	// and update_peer_port
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;
		TEST_EQUAL(p.num_connect_candidates(), 0);
		boost::shared_ptr<mock_peer_connection> c
			= boost::make_shared<mock_peer_connection>(&t, true, ep("10.0.0.1", 8080));
		p.new_connection(*c, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		TEST_EQUAL(p.num_peers(), 1);
		st.erased.clear();

		p.update_peer_port(4000, c->peer_info_struct(), peer_info::incoming, &st);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(c->peer_info_struct()->port, 4000);
		st.erased.clear();
	}

	// test incoming connection
	// and update_peer_port, causing collission
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = true;
		peer_list p;
		t.m_p = &p;

		torrent_peer* peer2 = p.add_peer(ep("10.0.0.1", 4000), 0, 0, &st);
		TEST_CHECK(peer2);

		TEST_EQUAL(p.num_connect_candidates(), 1);
		boost::shared_ptr<mock_peer_connection> c
			= boost::make_shared<mock_peer_connection>(&t, true, ep("10.0.0.1", 8080));
		p.new_connection(*c, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 1);
		// at this point we have two peers, because we think they have different 
		// ports
		TEST_EQUAL(p.num_peers(), 2);
		st.erased.clear();

		// this peer will end up having the same port as the existing peer in the list
		p.update_peer_port(4000, c->peer_info_struct(), peer_info::incoming, &st);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		// the expected behavior is to replace that one
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(c->peer_info_struct()->port, 4000);
		st.erased.clear();
	}

	// test ip filter
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// add peer 1
		torrent_peer* peer1 = add_peer(p, st, ep("10.0.0.2", 3000));
		torrent_peer* peer2 = add_peer(p, st, ep("11.0.0.2", 9020));

		TEST_CHECK(peer1 != peer2);

		connect_peer(p, t, st);
		connect_peer(p, t, st);

		boost::shared_ptr<mock_peer_connection> con1
			= static_cast<mock_peer_connection*>(peer1->connection)->shared_from_this();
		TEST_EQUAL(con1->was_disconnected(), false);
		boost::shared_ptr<mock_peer_connection> con2
			= static_cast<mock_peer_connection*>(peer2->connection)->shared_from_this();
		TEST_EQUAL(con2->was_disconnected(), false);

		// now, filter one of the IPs and make sure the peer is removed
		ip_filter filter;
		filter.add_rule(address_v4::from_string("11.0.0.0"), address_v4::from_string("255.255.255.255"), 1);
		std::vector<address> banned;
		p.apply_ip_filter(filter, &st, banned);
		// we just erased a peer, because it was filtered by the ip filter
		TEST_EQUAL(st.erased.size(), 1);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(banned.size(), 1);
		TEST_EQUAL(banned[0], address_v4::from_string("11.0.0.2"));
		TEST_EQUAL(con2->was_disconnected(), true);
		TEST_EQUAL(con1->was_disconnected(), false);
	}

	// test port filter
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// add peer 1
		torrent_peer* peer1 = add_peer(p, st, ep("10.0.0.2", 3000));
		torrent_peer* peer2 = add_peer(p, st, ep("11.0.0.2", 9020));

		TEST_CHECK(peer1 != peer2);

		connect_peer(p, t, st);
		connect_peer(p, t, st);

		boost::shared_ptr<mock_peer_connection> con1
			= static_cast<mock_peer_connection*>(peer1->connection)->shared_from_this();
		TEST_EQUAL(con1->was_disconnected(), false);
		boost::shared_ptr<mock_peer_connection> con2
			= static_cast<mock_peer_connection*>(peer2->connection)->shared_from_this();
		TEST_EQUAL(con2->was_disconnected(), false);

		// now, filter one of the IPs and make sure the peer is removed
		port_filter filter;
		filter.add_rule(9000, 10000, 1);
		std::vector<address> banned;
		p.apply_port_filter(filter, &st, banned);
		// we just erased a peer, because it was filtered by the ip filter
		TEST_EQUAL(st.erased.size(), 1);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(banned.size(), 1);
		TEST_EQUAL(banned[0], address_v4::from_string("11.0.0.2"));
		TEST_EQUAL(con2->was_disconnected(), true);
		TEST_EQUAL(con1->was_disconnected(), false);
	}

	// test banning peers
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		torrent_peer* peer1 = add_peer(p, st, ep("10.0.0.1", 4000));

		TEST_EQUAL(p.num_connect_candidates(), 1);
		boost::shared_ptr<mock_peer_connection> c
			= boost::make_shared<mock_peer_connection>(&t, true, ep("10.0.0.1", 8080));
		p.new_connection(*c, 0, &st);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		TEST_EQUAL(p.num_peers(), 1);
		st.erased.clear();

		// now, ban the peer
		bool ok = p.ban_peer(c->peer_info_struct());
		TEST_EQUAL(ok, true);
		TEST_EQUAL(peer1->banned, true);
		// we still have it in the list
		TEST_EQUAL(p.num_peers(), 1);
		// it's just not a connect candidate, nor allowed to receive incoming connections
		TEST_EQUAL(p.num_connect_candidates(), 0);

		p.connection_closed(*c, 0, &st);
		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		st.erased.clear();

		c = boost::make_shared<mock_peer_connection>(&t, true, ep("10.0.0.1", 8080));
		ok = p.new_connection(*c, 0, &st);
		// since it's banned, we should not allow this incoming connection
		TEST_EQUAL(ok, false);
		TEST_EQUAL(p.num_connect_candidates(), 0);
		st.erased.clear();
	}

	// test erase_peers when we fill up the peer list
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.max_peerlist_size = 100;
		st.allow_multiple_connections_per_ip = true;
		peer_list p;
		t.m_p = &p;

		for (int i = 0; i < 100; ++i)
		{
			TEST_EQUAL(st.erased.size(), 0);
			torrent_peer* peer = add_peer(p, st, rand_tcp_ep());
			TEST_CHECK(peer);
			if (peer == NULL || st.erased.size() > 0)
			{
				fprintf(stderr, "unexpected rejection of peer: %d in list. "
					"added peer %p, erased %d peers\n"
					, p.num_peers(), peer, int(st.erased.size()));
			}
		}
		TEST_EQUAL(p.num_peers(), 100);

		// trigger the eviction of one peer
		torrent_peer* peer = p.add_peer(rand_tcp_ep(), 0, 0, &st);
		// we either removed an existing peer, or rejected this one
		// either is valid behavior when the list is full
		TEST_CHECK(st.erased.size() == 1 || peer == NULL);
	}

	// test set_ip_filter
	{
		torrent_state st = init_state(allocator, ext_ip);
		std::vector<address> banned;

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		for (int i = 0; i < 100; ++i)
		{
			p.add_peer(tcp::endpoint(
				address_v4((10 << 24) + ((i + 10) << 16)), 353), 0, 0, &st);
			TEST_EQUAL(st.erased.size(), 0);
			st.erased.clear();
		}
		TEST_EQUAL(p.num_peers(), 100);
		TEST_EQUAL(p.num_connect_candidates(), 100);

		// trigger the removal of one peer
		ip_filter filter;
		filter.add_rule(address_v4::from_string("10.13.0.0")
			, address_v4::from_string("10.13.255.255"), ip_filter::blocked);
		p.apply_ip_filter(filter, &st, banned);
		TEST_EQUAL(st.erased.size(), 1);
		TEST_EQUAL(st.erased[0]->address(), address_v4::from_string("10.13.0.0"));
		TEST_EQUAL(p.num_peers(), 99);
		TEST_EQUAL(p.num_connect_candidates(), 99);
	}

	// test set_port_filter
	{
		torrent_state st = init_state(allocator, ext_ip);
		std::vector<address> banned;

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		for (int i = 0; i < 100; ++i)
		{
			p.add_peer(tcp::endpoint(
				address_v4((10 << 24) + ((i + 10) << 16)), i + 10), 0, 0, &st);
			TEST_EQUAL(st.erased.size(), 0);
			st.erased.clear();
		}
		TEST_EQUAL(p.num_peers(), 100);
		TEST_EQUAL(p.num_connect_candidates(), 100);

		// trigger the removal of one peer
		port_filter filter;
		filter.add_rule(13, 13, port_filter::blocked);
		p.apply_port_filter(filter, &st, banned);
		TEST_EQUAL(st.erased.size(), 1);
		TEST_EQUAL(st.erased[0]->address(), address_v4::from_string("10.13.0.0"));
		TEST_EQUAL(st.erased[0]->port, 13);
		TEST_EQUAL(p.num_peers(), 99);
		TEST_EQUAL(p.num_connect_candidates(), 99);
	}

	// test set_max_failcount
	{
		torrent_state st = init_state(allocator, ext_ip);

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		for (int i = 0; i < 100; ++i)
		{
			torrent_peer* peer = p.add_peer(tcp::endpoint(
				address_v4((10 << 24) + ((i + 10) << 16)), i + 10), 0, 0, &st);
			TEST_EQUAL(st.erased.size(), 0);
			st.erased.clear();
			// every other peer has a failcount of 1
			if (i % 2) p.inc_failcount(peer);
		}
		TEST_EQUAL(p.num_peers(), 100);
		TEST_EQUAL(p.num_connect_candidates(), 100);

		// set the max failcount to 1 and observe how half the peers no longer
		// are connect candidates
		st.max_failcount = 1;
		p.set_max_failcount(&st);

		TEST_EQUAL(p.num_connect_candidates(), 50);
		TEST_EQUAL(p.num_peers(), 100);
	}

	// test set_seed
	{
		torrent_state st = init_state(allocator, ext_ip);

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		for (int i = 0; i < 100; ++i)
		{
			torrent_peer* peer = p.add_peer(tcp::endpoint(
				address_v4((10 << 24) + ((i + 10) << 16)), i + 10), 0, 0, &st);
			TEST_EQUAL(st.erased.size(), 0);
			st.erased.clear();
			// make every other peer a seed
			if (i % 2) p.set_seed(peer, true);
		}
		TEST_EQUAL(p.num_peers(), 100);
		TEST_EQUAL(p.num_connect_candidates(), 100);

		// now, the torrent completes and we're no longer interested in
		// connecting to seeds. Make sure half the peers are no longer
		// considered connect candidates
		st.is_finished = true;

		// this will make the peer_list recalculate the connect candidates
		std::vector<torrent_peer*> peers;
		p.connect_one_peer(1, &st);

		TEST_EQUAL(p.num_connect_candidates(), 50);
		TEST_EQUAL(p.num_peers(), 100);
	}

	// test has_peer
	{
		torrent_state st = init_state(allocator, ext_ip);
		std::vector<address> banned;

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		torrent_peer* peer1 = add_peer(p, st, ep("10.10.0.1", 10));
		torrent_peer* peer2 = add_peer(p, st, ep("10.10.0.2", 11));

		TEST_EQUAL(p.num_peers(), 2);
		TEST_EQUAL(p.num_connect_candidates(), 2);

		TEST_EQUAL(p.has_peer(peer1), true);
		TEST_EQUAL(p.has_peer(peer2), true);

		ip_filter filter;
		filter.add_rule(address_v4::from_string("10.10.0.1")
			, address_v4::from_string("10.10.0.1"), ip_filter::blocked);
		p.apply_ip_filter(filter, &st, banned);
		TEST_EQUAL(st.erased.size(), 1);
		st.erased.clear();

		TEST_EQUAL(p.num_peers(), 1);
		TEST_EQUAL(p.num_connect_candidates(), 1);

		TEST_EQUAL(p.has_peer(peer1), false);
		TEST_EQUAL(p.has_peer(peer2), true);
	}

	// test connect_candidates torrent_finish
	{
		torrent_state st = init_state(allocator, ext_ip);
		std::vector<address> banned;

		mock_torrent t(&st);
		peer_list p;
		t.m_p = &p;

		torrent_peer* peer1 = add_peer(p, st, ep("10.10.0.1", 10));
		TEST_CHECK(peer1);
		p.set_seed(peer1, true);
		torrent_peer* peer2 = add_peer(p, st, ep("10.10.0.2", 11));
		TEST_CHECK(peer2);
		p.set_seed(peer2, true);
		torrent_peer* peer3 = add_peer(p, st, ep("10.10.0.3", 11));
		TEST_CHECK(peer3);
		p.set_seed(peer3, true);
		torrent_peer* peer4 = add_peer(p, st, ep("10.10.0.4", 11));
		TEST_CHECK(peer4);
		torrent_peer* peer5 = add_peer(p, st, ep("10.10.0.5", 11));
		TEST_CHECK(peer5);

		TEST_EQUAL(p.num_peers(), 5);
		TEST_EQUAL(p.num_connect_candidates(), 5);

		st.is_finished = true;
		// we're finished downloading now, only the non-seeds are
		// connect candidates

		// connect to one of them
		connect_peer(p, t, st);

		TEST_EQUAL(p.num_peers(), 5);
		// and there should be one left
		TEST_EQUAL(p.num_connect_candidates(), 1);
	}

	// test self-connection
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// add and connect peer
		torrent_peer* peer = add_peer(p, st, ep("10.0.0.2", 3000));
		connect_peer(p, t, st);

		boost::shared_ptr<mock_peer_connection> con_out
			= static_cast<mock_peer_connection*>(peer->connection)->shared_from_this();
		con_out->set_local_ep(ep("10.0.0.2", 8080));

		boost::shared_ptr<mock_peer_connection> con_in
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.0.2", 8080));
		con_in->set_local_ep(ep("10.0.0.2", 3000));

		p.new_connection(*con_in, 0, &st);

		// from the peer_list's point of view, this looks like we made one
		// outgoing connection and received an incoming one. Since they share
		// the exact same endpoints (IP ports) but just swapped source and
		// destination, the peer list is supposed to figure out that we connected
		// to ourself and disconnect it
		TEST_EQUAL(con_out->was_disconnected(), true);
		TEST_EQUAL(con_in->was_disconnected(), true);
	}

	// test double connection (both incoming)
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// we are 10.0.0.1 and the other peer is 10.0.0.2

		// first incoming connection
		boost::shared_ptr<mock_peer_connection> con1
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.0.2", 7528));
		con1->set_local_ep(ep("10.0.0.1", 8080));

		p.new_connection(*con1, 0, &st);

		// and the incoming connection
		boost::shared_ptr<mock_peer_connection> con2
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.0.2", 3561));
		con2->set_local_ep(ep("10.0.0.1", 8080));

		p.new_connection(*con2, 0, &st);

		// the second incoming connection should be closed
		TEST_EQUAL(con1->was_disconnected(), false);
		TEST_EQUAL(con2->was_disconnected(), true);
	}

	// test double connection (we loose)
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// we are 10.0.0.1 and the other peer is 10.0.0.2

		// our outgoing connection
		torrent_peer* peer = add_peer(p, st, ep("10.0.0.2", 3000));
		connect_peer(p, t, st);

		boost::shared_ptr<mock_peer_connection> con_out
			= static_cast<mock_peer_connection*>(peer->connection)->shared_from_this();
		con_out->set_local_ep(ep("10.0.0.1", 3163));

		// and the incoming connection
		boost::shared_ptr<mock_peer_connection> con_in
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.0.2", 3561));
		con_in->set_local_ep(ep("10.0.0.1", 8080));

		p.new_connection(*con_in, 0, &st);

		// the rules are documented in peer_list.cpp
		TEST_EQUAL(con_out->was_disconnected(), true);
		TEST_EQUAL(con_in->was_disconnected(), false);
	}

	// test double connection (we win)
	{
		torrent_state st = init_state(allocator, ext_ip);
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;

		// we are 10.0.0.1 and the other peer is 10.0.0.2

		// our outgoing connection
		torrent_peer* peer = add_peer(p, st, ep("10.0.0.2", 8080));
		connect_peer(p, t, st);

		boost::shared_ptr<mock_peer_connection> con_out
			= static_cast<mock_peer_connection*>(peer->connection)->shared_from_this();
		con_out->set_local_ep(ep("10.0.0.1", 3163));

		//and the incoming connection
		boost::shared_ptr<mock_peer_connection> con_in
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.0.2", 3561));
		con_in->set_local_ep(ep("10.0.0.1", 3000));

		p.new_connection(*con_in, 0, &st);

		// the rules are documented in peer_list.cpp
		TEST_EQUAL(con_out->was_disconnected(), false);
		TEST_EQUAL(con_in->was_disconnected(), true);
	}

	// test incoming connection when we are at the list size limit
	{
		torrent_state st = init_state(allocator, ext_ip);
		st.max_peerlist_size = 5;
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;
	
		torrent_peer* peer1 = add_peer(p, st, ep("10.0.0.1", 8080));
		TEST_CHECK(peer1);
		TEST_EQUAL(p.num_peers(), 1);
		torrent_peer* peer2 = add_peer(p, st, ep("10.0.0.2", 8080));
		TEST_CHECK(peer2);
		TEST_EQUAL(p.num_peers(), 2);
		torrent_peer* peer3 = add_peer(p, st, ep("10.0.0.3", 8080));
		TEST_CHECK(peer3);
		TEST_EQUAL(p.num_peers(), 3);
		torrent_peer* peer4 = add_peer(p, st, ep("10.0.0.4", 8080));
		TEST_CHECK(peer4);
		TEST_EQUAL(p.num_peers(), 4);
		torrent_peer* peer5 = add_peer(p, st, ep("10.0.0.5", 8080));
		TEST_CHECK(peer5);
		TEST_EQUAL(p.num_peers(), 5);

		boost::shared_ptr<mock_peer_connection> con_in
			= boost::make_shared<mock_peer_connection>(&t, false, ep("10.0.1.2", 3561));
		con_in->set_local_ep(ep("10.0.2.1", 3000));

		// since we're already at 5 peers in the peer list, this call should
		// erase one of the existing ones.
		p.new_connection(*con_in, 0, &st);

		TEST_EQUAL(con_in->was_disconnected(), false);
		TEST_EQUAL(p.num_peers(), 5);

		// one of the previous ones should have been removed
		TEST_EQUAL(has_peer(p, ep("10.0.0.1", 8080))
			+ has_peer(p, ep("10.0.0.2", 8080))
			+ has_peer(p, ep("10.0.0.3", 8080))
			+ has_peer(p, ep("10.0.0.4", 8080))
			+ has_peer(p, ep("10.0.0.5", 8080))
			, 4);
	}

	// test new peer when we are at the list size limit
	{
		torrent_state st = init_state(allocator, ext_ip);
		st.max_peerlist_size = 5;
		mock_torrent t(&st);
		st.allow_multiple_connections_per_ip = false;
		peer_list p;
		t.m_p = &p;
	
		torrent_peer* peer1 = add_peer(p, st, ep("10.0.0.1", 8080));
		TEST_CHECK(peer1);
		TEST_EQUAL(p.num_peers(), 1);
		torrent_peer* peer2 = add_peer(p, st, ep("10.0.0.2", 8080));
		TEST_CHECK(peer2);
		TEST_EQUAL(p.num_peers(), 2);
		torrent_peer* peer3 = add_peer(p, st, ep("10.0.0.3", 8080));
		TEST_CHECK(peer3);
		TEST_EQUAL(p.num_peers(), 3);
		torrent_peer* peer4 = add_peer(p, st, ep("10.0.0.4", 8080));
		TEST_CHECK(peer4);
		TEST_EQUAL(p.num_peers(), 4);
		torrent_peer* peer5 = add_peer(p, st, ep("10.0.0.5", 8080));
		TEST_CHECK(peer5);
		TEST_EQUAL(p.num_peers(), 5);
		torrent_peer* peer6 = p.add_peer(ep("10.0.0.6", 8080), 0, 0, &st);
		TEST_EQUAL(p.num_peers(), 5);

		// one of the connection should have been removed
		TEST_EQUAL(has_peer(p, ep("10.0.0.1", 8080))
			+ has_peer(p, ep("10.0.0.2", 8080))
			+ has_peer(p, ep("10.0.0.3", 8080))
			+ has_peer(p, ep("10.0.0.4", 8080))
			+ has_peer(p, ep("10.0.0.5", 8080))
			+ has_peer(p, ep("10.0.0.6", 8080))
			, 5);
	}

// TODO: test erasing peers
// TODO: test update_peer_port with allow_multiple_connections_per_ip and without
// TODO: test add i2p peers
// TODO: test allow_i2p_mixed
// TODO: test insert_peer failing with all error conditions
// TODO: test IPv6
// TODO: test connect_to_peer() failing
// TODO: test connection_closed
// TODO: connect candidates recalculation when incrementing failcount

	return 0;
}