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C++

// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012-2017 OpenVPN Inc.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License Version 3
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program in the COPYING file.
// If not, see <http://www.gnu.org/licenses/>.
// Client tun interface for Mac OS X
#ifndef OPENVPN_TUN_MAC_CLIENT_TUNCLI_H
#define OPENVPN_TUN_MAC_CLIENT_TUNCLI_H
#include <string>
#include <sstream>
#include <memory>
#include <openvpn/common/to_string.hpp>
#include <openvpn/asio/scoped_asio_stream.hpp>
#include <openvpn/common/cleanup.hpp>
#include <openvpn/tun/client/tunbase.hpp>
#include <openvpn/tun/client/tunprop.hpp>
#include <openvpn/tun/persist/tunpersist.hpp>
#include <openvpn/tun/persist/tunwrapasio.hpp>
#include <openvpn/tun/tunio.hpp>
#include <openvpn/tun/mac/client/tunsetup.hpp>
#ifdef TEST_EER // test emulated exclude routes
#include <openvpn/client/cliemuexr.hpp>
#endif
namespace openvpn {
namespace TunMac {
OPENVPN_EXCEPTION(tun_mac_error);
// struct used to pass received tun packets
struct PacketFrom
{
typedef std::unique_ptr<PacketFrom> SPtr;
BufferAllocated buf;
};
// tun interface wrapper for Mac OS X
template <typename ReadHandler, typename TunPersist>
class Tun : public TunIO<ReadHandler, PacketFrom, TunWrapAsioStream<TunPersist> >
{
typedef TunIO<ReadHandler, PacketFrom, TunWrapAsioStream<TunPersist> > Base;
public:
typedef RCPtr<Tun> Ptr;
Tun(const typename TunPersist::Ptr& tun_persist,
const std::string& name,
const bool retain_stream,
const bool tun_prefix,
ReadHandler read_handler,
const Frame::Ptr& frame,
const SessionStats::Ptr& stats)
: Base(read_handler, frame, stats)
{
Base::name_ = name;
Base::retain_stream = retain_stream;
Base::tun_prefix = tun_prefix;
Base::stream = new TunWrapAsioStream<TunPersist>(tun_persist);
}
};
// These types manage the underlying tun driver fd
typedef openvpn_io::posix::stream_descriptor TUNStream;
typedef ScopedAsioStream<TUNStream> ScopedTUNStream;
typedef TunPersistTemplate<ScopedTUNStream> TunPersist;
class Client;
class ClientConfig : public TunClientFactory
{
public:
typedef RCPtr<ClientConfig> Ptr;
TunProp::Config tun_prop;
int n_parallel = 8; // number of parallel async reads on tun socket
Frame::Ptr frame;
SessionStats::Ptr stats;
TunPersist::Ptr tun_persist;
Stop* stop = nullptr;
TunBuilderSetup::Factory::Ptr tun_setup_factory;
TunBuilderSetup::Base::Ptr new_setup_obj()
{
if (tun_setup_factory)
return tun_setup_factory->new_setup_obj();
else
return new TunMac::Setup();
}
static Ptr new_obj()
{
return new ClientConfig;
}
virtual TunClient::Ptr new_tun_client_obj(openvpn_io::io_context& io_context,
TunClientParent& parent,
TransportClient* transcli);
// return true if layer 2 tunnels are supported
virtual bool layer_2_supported() const
{
# if defined(MAC_TUNTAP_FALLBACK)
return false; // change to true after TAP support is added
# else
return false; // utun device doesn't support TAP
# endif
}
// called just prior to transmission of Disconnect event
virtual void finalize(const bool disconnected)
{
if (disconnected)
tun_persist.reset();
}
};
class Client : public TunClient
{
friend class ClientConfig; // calls constructor
friend class TunIO<Client*, PacketFrom, TunWrapAsioStream<TunPersist> >; // calls tun_read_handler
typedef Tun<Client*, TunPersist> TunImpl;
public:
virtual void tun_start(const OptionList& opt, TransportClient& transcli, CryptoDCSettings&) override
{
if (!impl)
{
halt = false;
if (config->tun_persist)
{
OPENVPN_LOG("TunPersist: long-term session scope");
tun_persist = config->tun_persist;
}
else
{
OPENVPN_LOG("TunPersist: short-term connection scope");
tun_persist.reset(new TunPersist(false, false, NULL));
}
try {
const IP::Addr server_addr = transcli.server_endpoint_addr();
// Check if persisted tun session matches properties of to-be-created session
if (tun_persist->use_persisted_tun(server_addr, config->tun_prop, opt))
{
state = tun_persist->state();
OPENVPN_LOG("TunPersist: reused tun context");
}
else
{
OPENVPN_LOG("TunPersist: new tun context");
// notify parent
parent.tun_pre_tun_config();
// close old tun handle if persisted
tun_persist->close();
// emulated exclude routes
EmulateExcludeRouteFactory::Ptr eer_factory;
#ifdef TEST_EER
eer_factory.reset(new EmulateExcludeRouteFactoryImpl(true));
#endif
// parse pushed options
TunBuilderCapture::Ptr po(new TunBuilderCapture());
TunProp::configure_builder(po.get(),
state.get(),
config->stats.get(),
server_addr,
config->tun_prop,
opt,
eer_factory.get(),
false);
// handle MTU default
if (!po->mtu)
po->mtu = 1500;
OPENVPN_LOG("CAPTURED OPTIONS:" << std::endl << po->to_string());
// create new tun setup object
tun_setup = config->new_setup_obj();
// create config object for tun setup layer
Setup::Config tsconf;
tsconf.iface_name = state->iface_name;
tsconf.layer = config->tun_prop.layer;
// open/config tun
int fd = -1;
{
std::ostringstream os;
auto os_print = Cleanup([&os](){ OPENVPN_LOG_STRING(os.str()); });
fd = tun_setup->establish(*po, &tsconf, config->stop, os);
}
// create ASIO wrapper for tun fd
TUNStream* ts = new TUNStream(io_context, fd);
// persist tun settings state
state->iface_name = tsconf.iface_name;
state->tun_prefix = tsconf.tun_prefix;
if (tun_persist->persist_tun_state(ts, state))
OPENVPN_LOG("TunPersist: saving tun context:" << std::endl << tun_persist->options());
// enable tun_setup destructor
tun_persist->add_destructor(tun_setup);
}
// configure tun interface packet forwarding
impl.reset(new TunImpl(tun_persist,
state->iface_name,
true,
state->tun_prefix,
this,
config->frame,
config->stats
));
impl->start(config->n_parallel);
// signal that we are connected
parent.tun_connected();
}
catch (const std::exception& e)
{
if (tun_persist)
tun_persist->close();
stop();
Error::Type err = Error::TUN_SETUP_FAILED;
const ExceptionCode *ec = dynamic_cast<const ExceptionCode *>(&e);
if (ec && ec->code_defined())
err = ec->code();
parent.tun_error(err, e.what());
}
}
}
virtual bool tun_send(BufferAllocated& buf) override
{
return send(buf);
}
virtual std::string tun_name() const override
{
if (impl)
return impl->name();
else
return "UNDEF_TUN";
}
virtual std::string vpn_ip4() const override
{
if (state->vpn_ip4_addr.specified())
return state->vpn_ip4_addr.to_string();
else
return "";
}
virtual std::string vpn_ip6() const override
{
if (state->vpn_ip6_addr.specified())
return state->vpn_ip6_addr.to_string();
else
return "";
}
virtual std::string vpn_gw4() const override
{
if (state->vpn_ip4_gw.specified())
return state->vpn_ip4_gw.to_string();
else
return "";
}
virtual std::string vpn_gw6() const override
{
if (state->vpn_ip6_gw.specified())
return state->vpn_ip6_gw.to_string();
else
return "";
}
virtual void set_disconnect() override
{
}
virtual void stop() override { stop_(); }
virtual ~Client() { stop_(); }
private:
Client(openvpn_io::io_context& io_context_arg,
ClientConfig* config_arg,
TunClientParent& parent_arg)
: io_context(io_context_arg),
config(config_arg),
parent(parent_arg),
halt(false),
state(new TunProp::State())
{
}
bool send(Buffer& buf)
{
if (impl)
return impl->write(buf);
else
return false;
}
void tun_read_handler(PacketFrom::SPtr& pfp) // called by TunImpl
{
parent.tun_recv(pfp->buf);
}
void tun_error_handler(const Error::Type errtype, // called by TunImpl
const openvpn_io::error_code* error)
{
parent.tun_error(Error::TUN_ERROR, "TUN I/O error");
}
void stop_()
{
if (!halt)
{
halt = true;
// stop tun
if (impl)
impl->stop();
tun_persist.reset();
}
}
openvpn_io::io_context& io_context;
TunPersist::Ptr tun_persist; // contains the tun device fd
ClientConfig::Ptr config;
TunClientParent& parent;
TunImpl::Ptr impl;
bool halt;
TunProp::State::Ptr state;
TunBuilderSetup::Base::Ptr tun_setup;
};
inline TunClient::Ptr ClientConfig::new_tun_client_obj(openvpn_io::io_context& io_context,
TunClientParent& parent,
TransportClient* transcli)
{
return TunClient::Ptr(new Client(io_context, this, parent));
}
}
} // namespace openvpn
#endif