tcp::endpoint utp_socket_manager::local_endpoint(address const& remote, error_code& ec) const
{
tcp::endpoint socket_ep = m_sock.local_endpoint(ec);
// first enumerate the routes in the routing table
if (time_now() - m_last_route_update > seconds(60))
{
m_last_route_update = time_now();
error_code ec;
m_routes = enum_routes(m_sock.get_io_service(), ec);
if (ec) return socket_ep;
}
if (m_routes.empty()) return socket_ep;
// then find the best match
ip_route* best = &m_routes[0];
for (std::vector<ip_route>::iterator i = m_routes.begin()
, end(m_routes.end()); i != end; ++i)
{
if (is_any(i->destination) && i->destination.is_v4() == remote.is_v4())
{
best = &*i;
continue;
}
if (match_addr_mask(remote, i->destination, i->netmask))
{
best = &*i;
continue;
}
}
// best now tells us which interface we would send over
// for this target. Now figure out what the local address
// is for that interface
if (time_now() - m_last_if_update > seconds(60))
{
m_last_if_update = time_now();
error_code ec;
m_interfaces = enum_net_interfaces(m_sock.get_io_service(), ec);
if (ec) return socket_ep;
}
for (std::vector<ip_interface>::iterator i = m_interfaces.begin()
, end(m_interfaces.end()); i != end; ++i)
{
if (i->interface_address.is_v4() != remote.is_v4())
continue;
if (strcmp(best->name, i->name) == 0)
return tcp::endpoint(i->interface_address, socket_ep.port());
}
return socket_ep;
}
void utp_socket_manager::mtu_for_dest(address const& addr, int& link_mtu, int& utp_mtu)
{
int mtu = 0;
if (is_teredo(addr)) mtu = TORRENT_TEREDO_MTU;
else mtu = TORRENT_ETHERNET_MTU;
#if defined __APPLE__
// apple has a very strange loopback. It appears you can't
// send messages of the reported MTU size, and you don't get
// EWOULDBLOCK either.
if (is_loopback(addr))
{
if (is_teredo(addr)) mtu = TORRENT_TEREDO_MTU;
else mtu = TORRENT_ETHERNET_MTU;
}
#endif
// clamp the MTU within reasonable bounds
if (mtu < TORRENT_INET_MIN_MTU) mtu = TORRENT_INET_MIN_MTU;
else if (mtu > TORRENT_INET_MAX_MTU) mtu = TORRENT_INET_MAX_MTU;
link_mtu = mtu;
mtu -= TORRENT_UDP_HEADER;
if (m_sock.get_proxy_settings().type == settings_pack::socks5
|| m_sock.get_proxy_settings().type == settings_pack::socks5_pw)
{
// this is for the IP layer
address proxy_addr = m_sock.proxy_addr().address();
if (proxy_addr.is_v4()) mtu -= TORRENT_IPV4_HEADER;
else mtu -= TORRENT_IPV6_HEADER;
// this is for the SOCKS layer
mtu -= TORRENT_SOCKS5_HEADER;
// the address field in the SOCKS header
if (addr.is_v4()) mtu -= 4;
else mtu -= 16;
}
else
{
if (addr.is_v4()) mtu -= TORRENT_IPV4_HEADER;
else mtu -= TORRENT_IPV6_HEADER;
}
utp_mtu = (std::min)(mtu, restrict_mtu());
}
void ip_filter::add_rule(address first, address last, int flags)
{
if (first.is_v4())
{
assert(last.is_v4());
m_filter4.add_rule(first.to_v4(), last.to_v4(), flags);
}
else if (first.is_v6())
{
assert(last.is_v6());
m_filter6.add_rule(first.to_v6(), last.to_v6(), flags);
}
else
assert(false);
}
int ip_filter::access(address const& addr) const
{
if (addr.is_v4())
return m_filter4.access(addr.to_v4());
assert(addr.is_v6());
return m_filter6.access(addr.to_v6());
}
void broadcast_socket::open_multicast_socket(
io_service& ios, address const& addr, bool loopback, error_code& ec)
{
using namespace asio::ip::multicast;
boost::shared_ptr<datagram_socket> s(new datagram_socket(ios));
s->open(addr.is_v4() ? udp::v4() : udp::v6(), ec);
if (ec) return;
s->set_option(datagram_socket::reuse_address(true), ec);
if (ec) return;
s->bind(udp::endpoint(addr, m_multicast_endpoint.port()), ec);
if (ec) return;
s->set_option(join_group(m_multicast_endpoint.address()), ec);
if (ec) return;
s->set_option(hops(255), ec);
if (ec) return;
s->set_option(enable_loopback(loopback), ec);
if (ec) return;
m_sockets.push_back(socket_entry(s));
socket_entry& se = m_sockets.back();
#if defined LIBED2K_ASIO_DEBUGGING
add_outstanding_async("broadcast_socket::on_receive");
#endif
s->async_receive_from(asio::buffer(se.buffer, sizeof(se.buffer)),
se.remote, boost::bind(&broadcast_socket::on_receive, this, &se, _1, _2));
++m_outstanding_operations;
}
inline T address_cast(const address& addr,
typename enable_if<is_same<T, address_v4>::value>::type* = 0)
{
if (!addr.is_v4())
throw bad_address_cast();
return get_v4_helper(addr);
}
void broadcast_socket::open_unicast_socket(
io_service& ios, address const& addr, address_v4 const& mask)
{
using namespace asio::ip::multicast;
error_code ec;
boost::shared_ptr<datagram_socket> s(new datagram_socket(ios));
s->open(addr.is_v4() ? udp::v4() : udp::v6(), ec);
if (ec) return;
s->bind(udp::endpoint(addr, 0), ec);
if (ec) return;
m_unicast_sockets.push_back(socket_entry(s, mask));
socket_entry& se = m_unicast_sockets.back();
// allow sending broadcast messages
asio::socket_base::broadcast option(true);
s->set_option(option, ec);
if (!ec) se.broadcast = true;
#if defined LIBED2K_ASIO_DEBUGGING
add_outstanding_async("broadcast_socket::on_receive");
#endif
s->async_receive_from(
asio::buffer(se.buffer, sizeof(se.buffer)), se.remote,
boost::bind(&broadcast_socket::on_receive, this, &se, _1, _2));
++m_outstanding_operations;
}
void ip_filter::add_rule(address first, address last, boost::uint32_t flags)
{
if (first.is_v4())
{
TORRENT_ASSERT(last.is_v4());
m_filter4.add_rule(first.to_v4().to_bytes(), last.to_v4().to_bytes(), flags);
}
#if TORRENT_USE_IPV6
else if (first.is_v6())
{
TORRENT_ASSERT(last.is_v6());
m_filter6.add_rule(first.to_v6().to_bytes(), last.to_v6().to_bytes(), flags);
}
#endif
else
TORRENT_ASSERT(false);
}
int ip_filter::access(address const& addr) const
{
if (addr.is_v4())
return m_filter4.access(addr.to_v4().to_bytes());
#if TORRENT_USE_IPV6
TORRENT_ASSERT(addr.is_v6());
return m_filter6.access(addr.to_v6().to_bytes());
#else
return 0;
#endif
}
// returns the number of bits in that differ from the right
// between the addresses.
int cidr_distance(address const& a1, address const& a2)
{
if (a1.is_v4() && a2.is_v4())
{
// both are v4
address_v4::bytes_type b1 = a1.to_v4().to_bytes();
address_v4::bytes_type b2 = a2.to_v4().to_bytes();
return address_v4::bytes_type::static_size * 8
- common_bits(b1.c_array(), b2.c_array(), b1.size());
}
address_v6::bytes_type b1;
address_v6::bytes_type b2;
if (a1.is_v4()) b1 = address_v6::v4_mapped(a1.to_v4()).to_bytes();
else b1 = a1.to_v6().to_bytes();
if (a2.is_v4()) b2 = address_v6::v4_mapped(a2.to_v4()).to_bytes();
else b2 = a2.to_v6().to_bytes();
return address_v6::bytes_type::static_size * 8
- common_bits(b1.c_array(), b2.c_array(), b1.size());
}
bool in_subnet(address const& addr, ip_interface const& iface)
{
if (addr.is_v4() != iface.interface_address.is_v4()) return false;
// since netmasks seems unreliable for IPv6 interfaces
// (MacOS X returns AF_INET addresses as bitmasks) assume
// that any IPv6 address belongs to the subnet of any
// interface with an IPv6 address
if (addr.is_v6()) return true;
return (addr.to_v4().to_ulong() & iface.netmask.to_v4().to_ulong())
== (iface.interface_address.to_v4().to_ulong() & iface.netmask.to_v4().to_ulong());
}
// returns the number of bits in that differ from the right
// between the addresses. The larger number, the further apart
// the IPs are
int cidr_distance(address const& a1, address const& a2)
{
#if LIBED2K_USE_IPV6
if (a1.is_v4() && a2.is_v4())
{
#endif
// both are v4
address_v4::bytes_type b1 = a1.to_v4().to_bytes();
address_v4::bytes_type b2 = a2.to_v4().to_bytes();
return address_v4::bytes_type().size() * 8 - common_bits(b1.data(), b2.data(), b1.size());
#if LIBED2K_USE_IPV6
}
address_v6::bytes_type b1;
address_v6::bytes_type b2;
if (a1.is_v4()) b1 = address_v6::v4_mapped(a1.to_v4()).to_bytes();
else b1 = a1.to_v6().to_bytes();
if (a2.is_v4()) b2 = address_v6::v4_mapped(a2.to_v4()).to_bytes();
else b2 = a2.to_v6().to_bytes();
return address_v6::bytes_type().size() * 8 - common_bits(b1.data(), b2.data(), b1.size());
#endif
}
void write_address(address const& a, OutIt& out)
{
if (a.is_v4())
{
write_uint32(a.to_v4().to_ulong(), out);
}
else if (a.is_v6())
{
address_v6::bytes_type bytes
= a.to_v6().to_bytes();
std::copy(bytes.begin(), bytes.end(), out);
}
}
void broadcast_socket::open_unicast_socket(io_service& ios, address const& addr)
{
using namespace asio::ip::multicast;
error_code ec;
boost::shared_ptr<datagram_socket> s(new datagram_socket(ios));
s->open(addr.is_v4() ? udp::v4() : udp::v6(), ec);
if (ec) return;
s->bind(udp::endpoint(addr, 0), ec);
if (ec) return;
m_unicast_sockets.push_back(socket_entry(s));
socket_entry& se = m_unicast_sockets.back();
s->async_receive_from(asio::buffer(se.buffer, sizeof(se.buffer))
, se.remote, bind(&broadcast_socket::on_receive, this, &se, _1, _2));
}
address mask_address(const address& addrIn, uint8_t prefixLen) {
if (addrIn.is_v4()) {
prefixLen = std::min<uint8_t>(prefixLen, 32);
uint32_t mask = get_subnet_mask_v4(prefixLen);
return address_v4(addrIn.to_v4().to_ulong() & mask);
}
struct in6_addr mask;
struct in6_addr addr6;
prefixLen = std::min<uint8_t>(prefixLen, 128);
compute_ipv6_subnet(addrIn.to_v6(), prefixLen, &mask, &addr6);
address_v6::bytes_type data;
std::memcpy(data.data(), &addr6, sizeof(addr6));
return address_v6(data);
}
void write_address(address const& a, OutIt&& out)
{
#if TORRENT_USE_IPV6
if (a.is_v4())
{
#endif
write_uint32(a.to_v4().to_ulong(), out);
#if TORRENT_USE_IPV6
}
else if (a.is_v6())
{
for (auto b : a.to_v6().to_bytes())
write_uint8(b, out);
}
#endif
}
void write_address(address const& a, OutIt& out)
{
#if TORRENT_USE_IPV6
if (a.is_v4())
{
#endif
write_uint32(a.to_v4().to_ulong(), out);
#if TORRENT_USE_IPV6
}
else if (a.is_v6())
{
address_v6::bytes_type bytes
= a.to_v6().to_bytes();
std::copy(bytes.begin(), bytes.end(), out);
}
#endif
}
void write_address(address const& a, OutIt& out)
{
#if TORRENT_USE_IPV6
if (a.is_v4())
{
#endif
write_uint32(a.to_v4().to_ulong(), out);
#if TORRENT_USE_IPV6
}
else if (a.is_v6())
{
typedef address_v6::bytes_type bytes_t;
bytes_t bytes = a.to_v6().to_bytes();
for (bytes_t::iterator i = bytes.begin()
, end(bytes.end()); i != end; ++i)
write_uint8(*i, out);
}
#endif
}
void natpmp::rebind(address const& listen_interface) try
{
address_v4 local = address_v4::any();
if (listen_interface.is_v4() && listen_interface != address_v4::any())
{
local = listen_interface.to_v4();
}
else
{
local = guess_local_address(m_socket.io_service());
if (local == address_v4::any())
{
throw std::runtime_error("local host is probably not on a NATed "
"network. disabling NAT-PMP");
}
}
#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
m_log << time_now_string()
<< " local ip: " << local.to_string() << std::endl;
#endif
if (!is_local(local))
{
// the local address seems to be an external
// internet address. Assume it is not behind a NAT
throw std::runtime_error("local IP is not on a local network");
}
m_disabled = false;
// assume the router is located on the local
// network as x.x.x.1
udp::endpoint nat_endpoint(
address_v4((local.to_ulong() & 0xffffff00) | 1), 5351);
if (nat_endpoint == m_nat_endpoint) return;
// TODO: find a better way to figure out the router IP
m_nat_endpoint = nat_endpoint;
#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
m_log << "assuming router is at: " << m_nat_endpoint.address().to_string() << std::endl;
#endif
m_socket.open(udp::v4());
m_socket.bind(udp::endpoint(address_v4::any(), 0));
for (int i = 0; i < num_mappings; ++i)
{
if (m_mappings[i].local_port == 0)
continue;
refresh_mapping(i);
}
}
catch (std::exception& e)
{
m_disabled = true;
std::stringstream msg;
msg << "NAT-PMP disabled: " << e.what();
#if defined(TORRENT_LOGGING) || defined(TORRENT_VERBOSE_LOGGING)
m_log << msg.str() << std::endl;
#endif
m_callback(0, 0, msg.str());
};
void utp_socket_manager::mtu_for_dest(address const& addr, int& link_mtu, int& utp_mtu)
{
if (time_now() - m_last_route_update > seconds(60))
{
m_last_route_update = time_now();
error_code ec;
m_routes = enum_routes(m_sock.get_io_service(), ec);
}
int mtu = 0;
if (!m_routes.empty())
{
for (std::vector<ip_route>::iterator i = m_routes.begin()
, end(m_routes.end()); i != end; ++i)
{
if (!match_addr_mask(addr, i->destination, i->netmask)) continue;
// assume that we'll actually use the route with the largest
// MTU (seems like a reasonable assumption).
// this could however be improved by using the route metrics
// and the prefix length of the netmask to order the matches
if (mtu < i->mtu) mtu = i->mtu;
}
}
if (mtu == 0)
{
if (is_teredo(addr)) mtu = TORRENT_TEREDO_MTU;
else mtu = TORRENT_ETHERNET_MTU;
}
// clamp the MTU within reasonable bounds
if (mtu < TORRENT_INET_MIN_MTU) mtu = TORRENT_INET_MIN_MTU;
else if (mtu > TORRENT_INET_MAX_MTU) mtu = TORRENT_INET_MAX_MTU;
link_mtu = mtu;
mtu -= TORRENT_UDP_HEADER;
if (m_sock.get_proxy_settings().type == proxy_settings::socks5
|| m_sock.get_proxy_settings().type == proxy_settings::socks5_pw)
{
// this is for the IP layer
address proxy_addr = m_sock.proxy_addr().address();
if (proxy_addr.is_v4()) mtu -= TORRENT_IPV4_HEADER;
else mtu -= TORRENT_IPV6_HEADER;
// this is for the SOCKS layer
mtu -= TORRENT_SOCKS5_HEADER;
// the address field in the SOCKS header
if (addr.is_v4()) mtu -= 4;
else mtu -= 16;
}
else
{
if (addr.is_v4()) mtu -= TORRENT_IPV4_HEADER;
else mtu -= TORRENT_IPV6_HEADER;
}
utp_mtu = mtu;
}
bool ip_voter::cast_vote(address const& ip
, int source_type, address const& source)
{
if (is_any(ip)) return false;
if (is_local(ip)) return false;
if (is_loopback(ip)) return false;
// don't trust source that aren't connected to us
// on a different address family than the external
// IP they claim we have
if (ip.is_v4() != source.is_v4()) return false;
// this is the key to use for the bloom filters
// it represents the identity of the voter
sha1_hash k;
hash_address(source, k);
// do we already have an entry for this external IP?
std::vector<external_ip_t>::iterator i = std::find_if(m_external_addresses.begin()
, m_external_addresses.end(), boost::bind(&external_ip_t::addr, _1) == ip);
if (i == m_external_addresses.end())
{
// each IP only gets to add a new IP once
if (m_external_address_voters.find(k)) return maybe_rotate();
if (m_external_addresses.size() > 40)
{
if (random() % 100 < 50)
return maybe_rotate();
// use stable sort here to maintain the fifo-order
// of the entries with the same number of votes
// this will sort in ascending order, i.e. the lowest
// votes first. Also, the oldest are first, so this
// is a sort of weighted LRU.
std::stable_sort(m_external_addresses.begin(), m_external_addresses.end());
// erase the last element, since it is one of the
// ones with the fewest votes
m_external_addresses.erase(m_external_addresses.end() - 1);
}
m_external_addresses.push_back(external_ip_t());
i = m_external_addresses.end() - 1;
i->addr = ip;
}
// add one more vote to this external IP
if (!i->add_vote(k, source_type)) return maybe_rotate();
++m_total_votes;
if (m_valid_external) return maybe_rotate();
i = std::min_element(m_external_addresses.begin(), m_external_addresses.end());
TORRENT_ASSERT(i != m_external_addresses.end());
if (i->addr == m_external_address) return maybe_rotate();
if (m_external_address != address_v4())
{
// we have a temporary external address. As soon as we have
// more than 25 votes, consider deciding which one to settle for
return (m_total_votes >= 25) ? maybe_rotate() : false;
}
m_external_address = i->addr;
return true;
}
