ZeroTierOne/node/EthernetTap.hpp

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/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2011-2014 ZeroTier Networks LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#ifndef ZT_ETHERNETTAP_HPP
#define ZT_ETHERNETTAP_HPP
#include <stdio.h>
#include <stdlib.h>
#include <map>
#include <list>
#include <vector>
#include <set>
#include <string>
#include <queue>
#include <stdexcept>
#include "Constants.hpp"
#include "InetAddress.hpp"
#include "MAC.hpp"
#include "Mutex.hpp"
#include "MulticastGroup.hpp"
#include "Thread.hpp"
#include "Buffer.hpp"
#include "Array.hpp"
#ifdef __WINDOWS__
#include <WinSock2.h>
#include <Windows.h>
#endif
namespace ZeroTier {
class RuntimeEnvironment;
/**
* System ethernet tap device
*/
class EthernetTap
{
public:
/**
* Construct a new TAP device
*
* Handler arguments: arg,from,to,etherType,data
*
* @param renv Runtime environment
* @param tag A tag used to identify persistent taps at the OS layer (e.g. nwid in hex)
* @param mac MAC address of device
* @param mtu MTU of device
* @param desc If non-NULL, a description (not used on all OSes)
* @param handler Handler function to be called when data is received from the tap
* @param arg First argument to handler function
* @throws std::runtime_error Unable to allocate device
*/
EthernetTap(
const RuntimeEnvironment *renv,
const char *tag,
const MAC &mac,
unsigned int mtu,
void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
void *arg)
throw(std::runtime_error);
/**
* Close tap and shut down thread
*
* This may block for a few seconds while thread exits.
*/
~EthernetTap();
/**
* Set the user display name for this connection
*
* This does nothing on platforms that don't have this concept.
*
* @param dn User display name
*/
void setDisplayName(const char *dn);
/**
* @return MAC address of this interface
*/
inline const MAC &mac() const throw() { return _mac; }
/**
* @return MTU of this interface
*/
inline unsigned int mtu() const throw() { return _mtu; }
/**
* Add an IP to this interface
*
* @param ip IP and netmask (netmask stored in port field)
* @return True if IP added successfully
*/
bool addIP(const InetAddress &ip);
/**
* Remove an IP from this interface
*
* Link-local IP addresses may not be able to be removed, depending on platform and type.
*
* @param ip IP and netmask (netmask stored in port field)
* @return True if IP removed successfully
*/
bool removeIP(const InetAddress &ip);
/**
* @return All IP addresses (V4 and V6) assigned to this interface (including link-local)
*/
std::set<InetAddress> ips() const;
/**
* Set this tap's IP addresses to exactly this set of IPs
*
* New IPs are created, ones not in this list are removed.
*
* @param ips IP addresses with netmask in port field
*/
inline void setIps(const std::set<InetAddress> &allIps)
{
for(std::set<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i)
addIP(*i);
std::set<InetAddress> myIps(ips());
#ifdef __APPLE__
bool haveV6LinkLocal = false;
for(std::set<InetAddress>::iterator i(myIps.begin());i!=myIps.end();++i) {
if (i->isLinkLocal()) {
if (i->isV6())
haveV6LinkLocal = true;
} else if (!allIps.count(*i))
removeIP(*i);
}
if (!haveV6LinkLocal)
addIP(InetAddress::makeIpv6LinkLocal(_mac));
#else
for(std::set<InetAddress>::iterator i(myIps.begin());i!=myIps.end();++i) {
if ((!i->isLinkLocal())&&(!allIps.count(*i)))
removeIP(*i);
}
#endif
}
/**
* Put a frame, making it available to the OS for processing
*
* @param from MAC address from which frame originated
* @param to MAC address of destination (typically MAC of tap itself)
* @param etherType Ethernet protocol ID
* @param data Frame payload
* @param len Length of frame
*/
void put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len);
/**
* @return OS-specific device or connection name
*/
std::string deviceName() const;
/**
* @return OS-internal persistent device ID or empty string if not applicable to this platform or not persistent
*/
std::string persistentId() const;
/**
* Fill or modify a set to contain multicast groups for this device
*
* This populates a set or, if already populated, modifies it to contain
* only multicast groups in which this device is interested.
*
* This should always include the blind wildcard MulticastGroup (MAC of
* ff:ff:ff:ff:ff:ff and 0 ADI field).
*
* @param groups Set to modify in place
* @return True if set was changed since last call
*/
bool updateMulticastGroups(std::set<MulticastGroup> &groups);
/**
* Thread main method; do not call elsewhere
*/
void threadMain()
throw();
/**
* Remove persistent tap device by device name
*
* This has no effect on platforms that do not have persistent taps.
* On platforms like Windows with persistent devices the device is
* uninstalled.
*
* @param _r Runtime environment
* @param pdev Device name as returned by persistentId() while tap is running
* @return True if a device was deleted
*/
static bool deletePersistentTapDevice(const RuntimeEnvironment *_r,const char *pid);
/**
* Clean persistent tap devices that are not in the supplied set
*
* This has no effect on platforms that do not have persistent taps.
* On platforms like Windows with persistent devices the device is
* uninstalled.
*
* @param _r Runtime environment
* @param exceptThese Devices to leave in place
* @param alsoRemoveUnassociatedDevices If true, remove devices not associated with any network as well
* @return Number of devices deleted or -1 if an error prevented the operation from being performed
*/
static int cleanPersistentTapDevices(const RuntimeEnvironment *_r,const std::set<std::string> &exceptThese,bool alsoRemoveUnassociatedDevices);
private:
const MAC _mac;
const unsigned int _mtu;
const RuntimeEnvironment *_r;
void (*_handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &);
void *_arg;
Thread _thread;
#ifdef __UNIX_LIKE__
char _dev[16];
int _fd;
int _shutdownSignalPipe[2];
#endif
#ifdef __WINDOWS__
void _syncIpsWithRegistry(const std::set<InetAddress> &haveIps);
HANDLE _tap;
OVERLAPPED _tapOvlRead,_tapOvlWrite;
char _tapReadBuf[ZT_IF_MTU + 32];
HANDLE _injectSemaphore;
GUID _deviceGuid;
std::string _myDeviceInstanceId; // NetCfgInstanceId, a GUID
std::string _myDeviceInstanceIdPath; // DeviceInstanceID, another kind of "instance ID"
std::queue< std::pair< Array<char,ZT_IF_MTU + 32>,unsigned int > > _injectPending;
Mutex _injectPending_m;
volatile bool _run;
volatile bool _initialized;
#endif
};
} // namespace ZeroTier
#endif