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// 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 Linux.
#ifndef OPENVPN_TUN_LINUX_CLIENT_TUNCLI_H
#define OPENVPN_TUN_LINUX_CLIENT_TUNCLI_H
#include <openvpn/asio/asioerr.hpp>
#include <openvpn/common/cleanup.hpp>
#include <openvpn/common/scoped_fd.hpp>
#include <openvpn/tun/builder/setup.hpp>
#include <openvpn/tun/tunio.hpp>
#include <openvpn/tun/persist/tunpersist.hpp>
// check if Netlink has been selected at compile time
#ifdef OPENVPN_USE_SITNL
#include <openvpn/tun/linux/client/tunnetlink.hpp>
#define TUN_LINUX openvpn::TunNetlink::TunMethods
#else
#include <openvpn/tun/linux/client/tuniproute.hpp>
#define TUN_LINUX openvpn::TunIPRoute::TunMethods
#endif
namespace openvpn {
namespace TunLinux {
struct PacketFrom
{
typedef std::unique_ptr<PacketFrom> SPtr;
BufferAllocated buf;
};
template <typename ReadHandler>
class Tun : public TunIO<ReadHandler, PacketFrom, openvpn_io::posix::stream_descriptor>
{
typedef TunIO<ReadHandler, PacketFrom, openvpn_io::posix::stream_descriptor> Base;
public:
typedef RCPtr<Tun> Ptr;
Tun(openvpn_io::io_context& io_context,
ReadHandler read_handler_arg,
const Frame::Ptr& frame_arg,
const SessionStats::Ptr& stats_arg,
const int socket,
const std::string& name)
: Base(read_handler_arg, frame_arg, stats_arg)
{
Base::name_ = name;
Base::retain_stream = true;
Base::stream = new openvpn_io::posix::stream_descriptor(io_context, socket);
OPENVPN_LOG_TUN(Base::name_ << " opened");
}
~Tun() { Base::stop(); }
};
typedef TunPersistTemplate<ScopedFD> TunPersist;
class ClientConfig : public TunClientFactory
{
public:
typedef RCPtr<ClientConfig> Ptr;
std::string dev_name;
int txqueuelen = 200;
TunProp::Config tun_prop;
int n_parallel = 8;
Frame::Ptr frame;
SessionStats::Ptr stats;
TunBuilderSetup::Factory::Ptr tun_setup_factory;
TunPersist::Ptr tun_persist;
void load(const OptionList& opt)
{
// set a default MTU
if (!tun_prop.mtu)
tun_prop.mtu = 1500;
// parse "dev" option
if (dev_name.empty())
{
const Option* dev = opt.get_ptr("dev");
if (dev)
dev_name = dev->get(1, 64);
}
}
static Ptr new_obj()
{
return new ClientConfig;
}
virtual TunClient::Ptr new_tun_client_obj(openvpn_io::io_context& io_context,
TunClientParent& parent,
TransportClient* transcli);
TunBuilderSetup::Base::Ptr new_setup_obj()
{
if (tun_setup_factory)
return tun_setup_factory->new_setup_obj();
else
return new TunLinuxSetup::Setup<TUN_LINUX>();
}
private:
ClientConfig() {}
};
class Client : public TunClient
{
friend class ClientConfig; // calls constructor
friend class TunIO<Client*, PacketFrom, openvpn_io::posix::stream_descriptor>; // calls tun_read_handler
typedef Tun<Client*> 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; // long-term persistent
}
else
{
OPENVPN_LOG("TunPersist: short-term connection scope");
tun_persist.reset(new TunPersist(true, false, nullptr)); // short-term
}
try {
const IP::Addr server_addr = transcli.server_endpoint_addr();
int sd = -1;
// 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();
sd = tun_persist->obj();
state = tun_persist->state();
OPENVPN_LOG("TunPersist: reused tun context");
}
else
{
// notify parent
parent.tun_pre_tun_config();
// close old tun handle if persisted
tun_persist->close();
// parse pushed options
TunBuilderCapture::Ptr po(new TunBuilderCapture());
TunProp::configure_builder(po.get(),
state.get(),
config->stats.get(),
server_addr,
config->tun_prop,
opt,
nullptr,
false);
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
TunLinuxSetup::Setup<TUN_LINUX>::Config tsconf;
tsconf.layer = config->tun_prop.layer;
tsconf.dev_name = config->dev_name;
tsconf.txqueuelen = config->txqueuelen;
tsconf.add_bypass_routes_on_establish = true;
// open/config tun
{
std::ostringstream os;
auto os_print = Cleanup([&os](){ OPENVPN_LOG_STRING(os.str()); });
sd = tun_setup->establish(*po, &tsconf, nullptr, os);
}
// persist tun settings state
state->iface_name = tsconf.iface_name;
tun_persist->persist_tun_state(sd, state);
// enable tun_setup destructor
tun_persist->add_destructor(tun_setup);
}
// start tun
impl.reset(new TunImpl(io_context,
this,
config->frame,
config->stats,
sd,
state->iface_name
));
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();
parent.tun_error(Error::TUN_SETUP_FAILED, 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),
state(new TunProp::State()),
halt(false)
{
}
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)
{
}
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;
ClientConfig::Ptr config;
TunClientParent& parent;
TunImpl::Ptr impl;
TunProp::State::Ptr state;
TunBuilderSetup::Base::Ptr tun_setup;
bool halt;
};
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 // OPENVPN_TUN_LINUX_CLIENT_TUNCLI_H