Split EthernetTap into subclasses, work in progress...

node/EthernetTap.hpp

@@ -31,67 +31,44 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#include <map>
-#include <list>
-#include <vector>
-#include <set>
 #include <string>
-#include <queue>
-#include <stdexcept>
+#include <set>
 
 #include "Constants.hpp"
-#include "InetAddress.hpp"
 #include "MAC.hpp"
-#include "Mutex.hpp"
-#include "MulticastGroup.hpp"
-#include "Thread.hpp"
+#include "InetAddress.hpp"
 #include "Buffer.hpp"
-#include "Array.hpp"
-
-#ifdef __WINDOWS__
-#include <WinSock2.h>
-#include <Windows.h>
-#endif
+#include "MulticastGroup.hpp"
+#include "NonCopyable.hpp"
 
 namespace ZeroTier {
 
-class RuntimeEnvironment;
-
 /**
- * System ethernet tap device
+ * Base class for Ethernet tap device implementations
  */
-class EthernetTap
+class EthernetTap : NonCopyable
 {
 public:
+	virtual ~EthernetTap() {}
+
 	/**
-	 * 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
+	 * @return Implementation class name (e.g. UnixEthernetTap)
 	 */
-	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);
+	inline const char *implementationName() const { return _implName; }
 
 	/**
-	 * Close tap and shut down thread
+	 * Sets whether device is 'up'
+	 *
+	 * This may do nothing on some platforms.
 	 *
-	 * This may block for a few seconds while thread exits.
+	 * @param en Is device enabled?
 	 */
-	~EthernetTap();
+	virtual void setEnabled(bool en) = 0;
+
+	/**
+	 * @return Is device 'up'?
+	 */
+	virtual bool enabled() const = 0;
 
 	/**
 	 * Set the user display name for this connection
@@ -100,7 +77,7 @@ public:
 	 *
 	 * @param dn User display name
 	 */
-	void setDisplayName(const char *dn);
+	virtual void setDisplayName(const char *dn) = 0;
 
 	/**
 	 * @return MAC address of this interface
@@ -118,7 +95,7 @@ public:
 	 * @param ip IP and netmask (netmask stored in port field)
 	 * @return True if IP added successfully
 	 */
-	bool addIP(const InetAddress &ip);
+	virtual bool addIP(const InetAddress &ip) = 0;
 
 	/**
 	 * Remove an IP from this interface
@@ -128,12 +105,12 @@ public:
 	 * @param ip IP and netmask (netmask stored in port field)
 	 * @return True if IP removed successfully
 	 */
-	bool removeIP(const InetAddress &ip);
+	virtual bool removeIP(const InetAddress &ip) = 0;
 
 	/**
 	 * @return All IP addresses (V4 and V6) assigned to this interface (including link-local)
 	 */
-	std::set<InetAddress> ips() const;
+	virtual std::set<InetAddress> ips() const = 0;
 
 	/**
 	 * Set this tap's IP addresses to exactly this set of IPs
@@ -175,17 +152,17 @@ public:
 	 * @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);
+	virtual void put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len) = 0;
 
 	/**
 	 * @return OS-specific device or connection name
 	 */
-	std::string deviceName() const;
+	virtual std::string deviceName() const = 0;
 
 	/**
 	 * @return OS-internal persistent device ID or empty string if not applicable to this platform or not persistent
 	 */
-	std::string persistentId() const;
+	virtual std::string persistentId() const = 0;
 
 	/**
 	 * Fill or modify a set to contain multicast groups for this device
@@ -199,73 +176,17 @@ public:
 	 * @param groups Set to modify in place
 	 * @return True if set was changed since last call
 	 */
-	bool updateMulticastGroups(std::set<MulticastGroup> &groups);
+	virtual bool updateMulticastGroups(std::set<MulticastGroup> &groups) = 0;
 
-	/**
-	 * Thread main method; do not call elsewhere
-	 */
-	void threadMain()
-		throw();
+protected:
+	EthernetTap(const char *cn,const MAC &m,unsigned int mt) :
+		_implName(cn),
+		_mac(m),
+		_mtu(mt) {}
 
-	/**
-	 * 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
+	const char *_implName;
+	MAC _mac;
+	unsigned int _mtu;
 };
 
 } // namespace ZeroTier

node/UnixEthernetTap.cpp

@@ -0,0 +1,1007 @@
+/*
+ * 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/
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+#include <sys/select.h>
+#include <netinet/in.h>
+#include <net/if_arp.h>
+#include <arpa/inet.h>
+
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+
+#include "Constants.hpp"
+#include "UnixEthernetTap.hpp"
+#include "Logger.hpp"
+#include "RuntimeEnvironment.hpp"
+#include "Utils.hpp"
+#include "Mutex.hpp"
+
+// ff:ff:ff:ff:ff:ff with no ADI
+static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
+
+// Command identifiers used with command finder static (on various *nixes)
+#define ZT_UNIX_IP_COMMAND 1
+#define ZT_UNIX_IFCONFIG_COMMAND 2
+#define ZT_MAC_KEXTLOAD_COMMAND 3
+#define ZT_MAC_KEXTUNLOAD_COMMAND 4
+
+// Finds external commands on startup ----------------------------------------
+class _CommandFinder
+{
+public:
+	_CommandFinder()
+	{
+		_findCmd(ZT_UNIX_IFCONFIG_COMMAND,"ifconfig");
+#ifdef __LINUX__
+		_findCmd(ZT_UNIX_IP_COMMAND,"ip");
+#endif
+#ifdef __APPLE__
+		_findCmd(ZT_MAC_KEXTLOAD_COMMAND,"kextload");
+		_findCmd(ZT_MAC_KEXTUNLOAD_COMMAND,"kextunload");
+#endif
+	}
+	inline const char *operator[](int id) const
+		throw()
+	{
+		std::map<int,std::string>::const_iterator c(_paths.find(id));
+		if (c == _paths.end())
+			return (const char *)0;
+		return c->second.c_str();
+	}
+private:
+	inline void _findCmd(int id,const char *name)
+	{
+		char tmp[4096];
+		ZeroTier::Utils::snprintf(tmp,sizeof(tmp),"/sbin/%s",name);
+		if (ZeroTier::Utils::fileExists(tmp)) {
+			_paths[id] = tmp;
+			return;
+		}
+		ZeroTier::Utils::snprintf(tmp,sizeof(tmp),"/usr/sbin/%s",name);
+		if (ZeroTier::Utils::fileExists(tmp)) {
+			_paths[id] = tmp;
+			return;
+		}
+		ZeroTier::Utils::snprintf(tmp,sizeof(tmp),"/bin/%s",name);
+		if (ZeroTier::Utils::fileExists(tmp)) {
+			_paths[id] = tmp;
+			return;
+		}
+		ZeroTier::Utils::snprintf(tmp,sizeof(tmp),"/usr/bin/%s",name);
+		if (ZeroTier::Utils::fileExists(tmp)) {
+			_paths[id] = tmp;
+			return;
+		}
+	}
+	std::map<int,std::string> _paths;
+};
+static const _CommandFinder UNIX_COMMANDS;
+// ---------------------------------------------------------------------------
+
+#ifdef __LINUX__
+#include <linux/if.h>
+#include <linux/if_tun.h>
+#include <linux/if_addr.h>
+#include <linux/if_ether.h>
+#include <ifaddrs.h>
+#endif // __LINUX__
+
+#ifdef __APPLE__
+
+#include <sys/cdefs.h>
+#include <sys/uio.h>
+#include <sys/param.h>
+#include <sys/sysctl.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/route.h>
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/if_media.h>
+struct prf_ra { // stupid OSX compile fix... in6_var defines this in a struct which namespaces it for C++
+	u_char onlink : 1;
+	u_char autonomous : 1;
+	u_char reserved : 6;
+} prf_ra;
+#include <netinet6/in6_var.h>
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/icmp6.h>
+#include <netinet6/nd6.h>
+#include <ifaddrs.h>
+
+// These are KERNEL_PRIVATE... why?
+#ifndef SIOCAUTOCONF_START
+#define SIOCAUTOCONF_START _IOWR('i', 132, struct in6_ifreq)    /* accept rtadvd on this interface */
+#endif
+#ifndef SIOCAUTOCONF_STOP
+#define SIOCAUTOCONF_STOP _IOWR('i', 133, struct in6_ifreq)    /* stop accepting rtadv for this interface */
+#endif
+
+static volatile int EthernetTap_instances = 0;
+static ZeroTier::Mutex EthernetTap_instances_m;
+
+static inline bool _setIpv6Stuff(const char *ifname,bool performNUD,bool acceptRouterAdverts)
+{
+	struct in6_ndireq nd;
+	struct in6_ifreq ifr;
+
+	int s = socket(AF_INET6,SOCK_DGRAM,0);
+	if (s <= 0)
+		return false;
+
+	memset(&nd,0,sizeof(nd));
+	strncpy(nd.ifname,ifname,sizeof(nd.ifname));
+
+	if (ioctl(s,SIOCGIFINFO_IN6,&nd)) {
+		close(s);
+		return false;
+	}
+
+	unsigned long oldFlags = (unsigned long)nd.ndi.flags;
+
+	if (performNUD)
+		nd.ndi.flags |= ND6_IFF_PERFORMNUD;
+	else nd.ndi.flags &= ~ND6_IFF_PERFORMNUD;
+
+	if (oldFlags != (unsigned long)nd.ndi.flags) {
+		if (ioctl(s,SIOCSIFINFO_FLAGS,&nd)) {
+			close(s);
+			return false;
+		}
+	}
+
+	memset(&ifr,0,sizeof(ifr));
+	strncpy(ifr.ifr_name,ifname,sizeof(ifr.ifr_name));
+	if (ioctl(s,acceptRouterAdverts ? SIOCAUTOCONF_START : SIOCAUTOCONF_STOP,&ifr)) {
+		close(s);
+		return false;
+	}
+
+	close(s);
+	return true;
+}
+
+#endif // __APPLE__
+
+namespace ZeroTier {
+
+// Only permit one tap to be opened concurrently across the entire process
+static Mutex __tapCreateLock;
+
+#ifdef __LINUX__
+UnixEthernetTap::UnixEthernetTap(
+	const RuntimeEnvironment *renv,
+	const char *tryToGetDevice,
+	const MAC &mac,
+	unsigned int mtu,
+	void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
+	void *arg)
+	throw(std::runtime_error) :
+	EthernetTap("UnixEthernetTap",mac,mtu),
+	_r(renv),
+	_handler(handler),
+	_arg(arg),
+	_fd(0),
+	_enabled(true)
+{
+	char procpath[128];
+	struct stat sbuf;
+	Mutex::Lock _l(__tapCreateLock); // create only one tap at a time, globally
+
+	if (mtu > 4096)
+		throw std::runtime_error("max tap MTU is 4096");
+
+	_fd = ::open("/dev/net/tun",O_RDWR);
+	if (_fd <= 0)
+		throw std::runtime_error(std::string("could not open TUN/TAP device: ") + strerror(errno));
+
+	struct ifreq ifr;
+	memset(&ifr,0,sizeof(ifr));
+
+	// Try to recall our last device name, or pick an unused one if that fails.
+	bool recalledDevice = false;
+	if ((tryToGetDevice)&&(tryToGetDevice[0])) {
+		Utils::scopy(ifr.ifr_name,sizeof(ifr.ifr_name),tryToGetDevice);
+		Utils::snprintf(procpath,sizeof(procpath),"/proc/sys/net/ipv4/conf/%s",ifr.ifr_name);
+		recalledDevice = (stat(procpath,&sbuf) != 0);
+	}
+	if (!recalledDevice) {
+		int devno = 0;
+		do {
+			Utils::snprintf(ifr.ifr_name,sizeof(ifr.ifr_name),"zt%d",devno++);
+			Utils::snprintf(procpath,sizeof(procpath),"/proc/sys/net/ipv4/conf/%s",ifr.ifr_name);
+		} while (stat(procpath,&sbuf) == 0); // try zt#++ until we find one that does not exist
+	}
+
+	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+	if (ioctl(_fd,TUNSETIFF,(void *)&ifr) < 0) {
+		::close(_fd);
+		throw std::runtime_error("unable to configure TUN/TAP device for TAP operation");
+	}
+
+	_dev = ifr.ifr_name;
+
+	ioctl(_fd,TUNSETPERSIST,0); // valgrind may generate a false alarm here
+
+	// Open an arbitrary socket to talk to netlink
+	int sock = socket(AF_INET,SOCK_DGRAM,0);
+	if (sock <= 0) {
+		::close(_fd);
+		throw std::runtime_error("unable to open netlink socket");
+	}
+
+	// Set MAC address
+	ifr.ifr_ifru.ifru_hwaddr.sa_family = ARPHRD_ETHER;
+	memcpy(ifr.ifr_ifru.ifru_hwaddr.sa_data,mac.data,6);
+	if (ioctl(sock,SIOCSIFHWADDR,(void *)&ifr) < 0) {
+		::close(_fd);
+		::close(sock);
+		throw std::runtime_error("unable to configure TAP hardware (MAC) address");
+		return;
+	}
+
+	// Set MTU
+	ifr.ifr_ifru.ifru_mtu = (int)mtu;
+	if (ioctl(sock,SIOCSIFMTU,(void *)&ifr) < 0) {
+		::close(_fd);
+		::close(sock);
+		throw std::runtime_error("unable to configure TAP MTU");
+	}
+
+	if (fcntl(_fd,F_SETFL,fcntl(_fd,F_GETFL) & ~O_NONBLOCK) == -1) {
+		::close(_fd);
+		throw std::runtime_error("unable to set flags on file descriptor for TAP device");
+	}
+
+	/* Bring interface up */
+	if (ioctl(sock,SIOCGIFFLAGS,(void *)&ifr) < 0) {
+		::close(_fd);
+		::close(sock);
+		throw std::runtime_error("unable to get TAP interface flags");
+	}
+	ifr.ifr_flags |= IFF_UP;
+	if (ioctl(sock,SIOCSIFFLAGS,(void *)&ifr) < 0) {
+		::close(_fd);
+		::close(sock);
+		throw std::runtime_error("unable to set TAP interface flags");
+	}
+
+	::close(sock);
+
+	::pipe(_shutdownSignalPipe);
+
+	TRACE("tap %s created",_dev.c_str());
+
+	_thread = Thread::start(this);
+}
+#endif // __LINUX__
+
+#ifdef __APPLE__
+UnixEthernetTap::UnixEthernetTap(
+	const RuntimeEnvironment *renv,
+	const char *tryToGetDevice,
+	const MAC &mac,
+	unsigned int mtu,
+	void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
+	void *arg)
+	throw(std::runtime_error) :
+	EthernetTap("UnixEthernetTap",mac,mtu),
+	_r(renv),
+	_handler(handler),
+	_arg(arg),
+	_fd(0),
+	_enabled(true)
+{
+	char devpath[64],ethaddr[64],mtustr[16],tmp[4096];
+	struct stat stattmp;
+	Mutex::Lock _l(__tapCreateLock); // create only one tap at a time, globally
+
+	if (mtu > 4096)
+		throw std::runtime_error("max tap MTU is 4096");
+
+	// Check for existence of ZT tap devices, try to load module if not there
+	const char *kextload = UNIX_COMMANDS[ZT_MAC_KEXTLOAD_COMMAND];
+	if ((stat("/dev/zt0",&stattmp))&&(kextload)) {
+		strcpy(tmp,_r->homePath.c_str());
+		long kextpid = (long)vfork();
+		if (kextpid == 0) {
+			chdir(tmp);
+			execl(kextload,kextload,"-q","-repository",tmp,"tap.kext",(const char *)0);
+			_exit(-1);
+		} else if (kextpid > 0) {
+			int exitcode = -1;
+			waitpid(kextpid,&exitcode,0);
+			usleep(500);
+		} else throw std::runtime_error("unable to create subprocess with fork()");
+	}
+	if (stat("/dev/zt0",&stattmp))
+		throw std::runtime_error("/dev/zt# tap devices do not exist and unable to load kernel extension");
+
+	// Try to reopen the last device we had, if we had one and it's still unused.
+	bool recalledDevice = false;
+	if ((tryToGetDevice)&&(tryToGetDevice[0])) {
+		Utils::snprintf(devpath,sizeof(devpath),"/dev/%s",tryToGetDevice);
+		if (stat(devpath,&stattmp) == 0) {
+			_fd = ::open(devpath,O_RDWR);
+			if (_fd > 0) {
+				_dev = tryToGetDevice;
+				recalledDevice = true;
+			}
+		}
+	}
+
+	// Open the first unused tap device if we didn't recall a previous one.
+	if (!recalledDevice) {
+		for(int i=0;i<256;++i) {
+			Utils::snprintf(devpath,sizeof(devpath),"/dev/zt%d",i);
+			if (stat(devpath,&stattmp))
+				throw std::runtime_error("no more TAP devices available");
+			_fd = ::open(devpath,O_RDWR);
+			if (_fd > 0) {
+				char foo[16];
+				Utils::snprintf(foo,sizeof(foo),"zt%d",i);
+				_dev = foo;
+				break;
+			}
+		}
+	}
+
+	if (_fd <= 0)
+		throw std::runtime_error("unable to open TAP device or no more devices available");
+
+	if (fcntl(_fd,F_SETFL,fcntl(_fd,F_GETFL) & ~O_NONBLOCK) == -1) {
+		::close(_fd);
+		throw std::runtime_error("unable to set flags on file descriptor for TAP device");
+	}
+
+	const char *ifconfig = UNIX_COMMANDS[ZT_UNIX_IFCONFIG_COMMAND];
+	if (!ifconfig) {
+		::close(_fd);
+		throw std::runtime_error("unable to find 'ifconfig' command on system");
+	}
+
+	// Configure MAC address and MTU, bring interface up
+	Utils::snprintf(ethaddr,sizeof(ethaddr),"%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",(int)mac[0],(int)mac[1],(int)mac[2],(int)mac[3],(int)mac[4],(int)mac[5]);
+	Utils::snprintf(mtustr,sizeof(mtustr),"%u",mtu);
+	long cpid;
+	if ((cpid = (long)vfork()) == 0) {
+		execl(ifconfig,ifconfig,_dev.c_str(),"lladdr",ethaddr,"mtu",mtustr,"up",(const char *)0);
+		_exit(-1);
+	} else {
+		int exitcode = -1;
+		waitpid(cpid,&exitcode,0);
+		if (exitcode) {
+			::close(_fd);
+			throw std::runtime_error("ifconfig failure setting link-layer address and activating tap interface");
+		}
+	}
+
+	_setIpv6Stuff(_dev.c_str(),true,false);
+
+	::pipe(_shutdownSignalPipe);
+
+	_thread = Thread::start(this);
+
+	EthernetTap_instances_m.lock();
+	++EthernetTap_instances;
+	EthernetTap_instances_m.unlock();
+}
+#endif // __APPLE__
+
+UnixEthernetTap::~UnixEthernetTap()
+{
+	::write(_shutdownSignalPipe[1],"\0",1); // causes thread to exit
+	Thread::join(_thread);
+	::close(_fd);
+
+#ifdef __APPLE__
+	EthernetTap_instances_m.lock();
+	int instances = --EthernetTap_instances;
+	EthernetTap_instances_m.unlock();
+	if (instances <= 0) {
+		// Unload OSX kernel extension on the deletion of the last EthernetTap
+		// instance.
+		const char *kextunload = UNIX_COMMANDS[ZT_MAC_KEXTUNLOAD_COMMAND];
+		if (kextunload) {
+			char tmp[4096];
+			sprintf(tmp,"%s/tap.kext",_r->homePath.c_str());
+			long kextpid = (long)vfork();
+			if (kextpid == 0) {
+				execl(kextunload,kextunload,tmp,(const char *)0);
+				_exit(-1);
+			} else if (kextpid > 0) {
+				int exitcode = -1;
+				waitpid(kextpid,&exitcode,0);
+			}
+		}
+	}
+#endif // __APPLE__
+}
+
+void UnixEthernetTap::setEnabled(bool en)
+{
+	_enabled = en;
+	// TODO: interface status change
+}
+
+bool UnixEthernetTap::enabled() const
+{
+	return _enabled;
+}
+
+void UnixEthernetTap::setDisplayName(const char *dn)
+{
+}
+
+#ifdef __LINUX__
+static bool ___removeIp(const std::string &_dev,const InetAddress &ip)
+{
+	const char *ipcmd = UNIX_COMMANDS[ZT_UNIX_IP_COMMAND];
+	if (!ipcmd)
+		return false;
+	long cpid = (long)vfork();
+	if (cpid == 0) {
+		execl(ipcmd,ipcmd,"addr","del",ip.toString().c_str(),"dev",_dev.c_str(),(const char *)0);
+		_exit(-1);
+	} else {
+		int exitcode = -1;
+		waitpid(cpid,&exitcode,0);
+		return (exitcode == 0);
+	}
+}
+
+bool UnixEthernetTap::addIP(const InetAddress &ip)
+{
+	const char *ipcmd = UNIX_COMMANDS[ZT_UNIX_IP_COMMAND];
+	if (!ipcmd) {
+		LOG("ERROR: could not configure IP address for %s: unable to find 'ip' command on system (checked /sbin, /bin, /usr/sbin, /usr/bin)",_dev.c_str());
+		return false;
+	}
+
+	if (!ip)
+		return false;
+
+	std::set<InetAddress> allIps(ips());
+	if (allIps.count(ip) > 0)
+		return true;
+
+	// Remove and reconfigure if address is the same but netmask is different
+	for(std::set<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i) {
+		if (i->ipsEqual(ip)) {
+			if (___removeIp(_dev,*i)) {
+				break;
+			} else {
+				LOG("WARNING: failed to remove old IP/netmask %s to replace with %s",i->toString().c_str(),ip.toString().c_str());
+			}
+		}
+	}
+
+	long cpid;
+	if ((cpid = (long)vfork()) == 0) {
+		execl(ipcmd,ipcmd,"addr","add",ip.toString().c_str(),"dev",_dev.c_str(),(const char *)0);
+		_exit(-1);
+	} else if (cpid > 0) {
+		int exitcode = -1;
+		waitpid(cpid,&exitcode,0);
+		return (exitcode == 0);
+	}
+
+	return false;
+}
+#endif // __LINUX__
+
+#ifdef __APPLE__
+static bool ___removeIp(const std::string &_dev,const InetAddress &ip)
+{
+	const char *ifconfig = UNIX_COMMANDS[ZT_UNIX_IFCONFIG_COMMAND];
+	if (!ifconfig)
+		return false;
+	long cpid;
+	if ((cpid = (long)vfork()) == 0) {
+		execl(ifconfig,ifconfig,_dev.c_str(),"inet",ip.toIpString().c_str(),"-alias",(const char *)0);
+		_exit(-1);
+	} else {
+		int exitcode = -1;
+		waitpid(cpid,&exitcode,0);
+		return (exitcode == 0);
+	}
+	return false; // never reached, make compiler shut up about return value
+}
+
+bool UnixEthernetTap::addIP(const InetAddress &ip)
+{
+	const char *ifconfig = UNIX_COMMANDS[ZT_UNIX_IFCONFIG_COMMAND];
+	if (!ifconfig) {
+		LOG("ERROR: could not configure IP address for %s: unable to find 'ifconfig' command on system (checked /sbin, /bin, /usr/sbin, /usr/bin)",_dev.c_str());
+		return false;
+	}
+
+	if (!ip)
+		return false;
+
+	std::set<InetAddress> allIps(ips());
+	if (allIps.count(ip) > 0)
+		return true; // IP/netmask already assigned
+
+	// Remove and reconfigure if address is the same but netmask is different
+	for(std::set<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i) {
+		if ((i->ipsEqual(ip))&&(i->netmaskBits() != ip.netmaskBits())) {
+			if (___removeIp(_dev,*i)) {
+				break;
+			} else {
+				LOG("WARNING: failed to remove old IP/netmask %s to replace with %s",i->toString().c_str(),ip.toString().c_str());
+			}
+		}
+	}
+
+	long cpid;
+	if ((cpid = (long)vfork()) == 0) {
+		execl(ifconfig,ifconfig,_dev.c_str(),ip.isV4() ? "inet" : "inet6",ip.toString().c_str(),"alias",(const char *)0);
+		_exit(-1);
+	} else {
+		int exitcode = -1;
+		waitpid(cpid,&exitcode,0);
+		return (exitcode == 0);
+	}
+
+	return false;
+}
+#endif // __APPLE__
+
+bool UnixEthernetTap::removeIP(const InetAddress &ip)
+{
+	if (ips().count(ip) > 0) {
+		if (___removeIp(_dev,ip))
+			return true;
+	}
+	return false;
+}
+
+std::set<InetAddress> UnixEthernetTap::ips() const
+{
+	struct ifaddrs *ifa = (struct ifaddrs *)0;
+	if (getifaddrs(&ifa))
+		return std::set<InetAddress>();
+
+	std::set<InetAddress> r;
+
+	struct ifaddrs *p = ifa;
+	while (p) {
+		if ((!strcmp(p->ifa_name,_dev.c_str()))&&(p->ifa_addr)&&(p->ifa_netmask)&&(p->ifa_addr->sa_family == p->ifa_netmask->sa_family)) {
+			switch(p->ifa_addr->sa_family) {
+				case AF_INET: {
+					struct sockaddr_in *sin = (struct sockaddr_in *)p->ifa_addr;
+					struct sockaddr_in *nm = (struct sockaddr_in *)p->ifa_netmask;
+					r.insert(InetAddress(&(sin->sin_addr.s_addr),4,Utils::countBits((uint32_t)nm->sin_addr.s_addr)));
+				}	break;
+				case AF_INET6: {
+					struct sockaddr_in6 *sin = (struct sockaddr_in6 *)p->ifa_addr;
+					struct sockaddr_in6 *nm = (struct sockaddr_in6 *)p->ifa_netmask;
+					uint32_t b[4];
+					memcpy(b,nm->sin6_addr.s6_addr,sizeof(b));
+					r.insert(InetAddress(sin->sin6_addr.s6_addr,16,Utils::countBits(b[0]) + Utils::countBits(b[1]) + Utils::countBits(b[2]) + Utils::countBits(b[3])));
+				}	break;
+			}
+		}
+		p = p->ifa_next;
+	}
+
+	if (ifa)
+		freeifaddrs(ifa);
+
+	return r;
+}
+
+void UnixEthernetTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
+{
+	char putBuf[4096 + 14];
+	if ((_fd > 0)&&(len <= _mtu)) {
+		for(int i=0;i<6;++i)
+			putBuf[i] = to.data[i];
+		for(int i=0;i<6;++i)
+			putBuf[i+6] = from.data[i];
+		*((uint16_t *)(putBuf + 12)) = htons((uint16_t)etherType);
+		memcpy(putBuf + 14,data,len);
+		len += 14;
+
+		int n = ::write(_fd,putBuf,len);
+		if (n <= 0) {
+			LOG("error writing packet to Ethernet tap device: %s",strerror(errno));
+		} else if (n != (int)len) {
+			// Saw this gremlin once, so log it if we see it again... OSX tap
+			// or something seems to have goofy issues with certain MTUs.
+			LOG("ERROR: write underrun: %s tap write() wrote %d of %u bytes of frame",_dev.c_str(),n,len);
+		}
+	}
+}
+
+std::string UnixEthernetTap::deviceName() const
+{
+	return _dev;
+}
+
+std::string UnixEthernetTap::persistentId() const
+{
+	return std::string();
+}
+
+#ifdef __LINUX__
+bool UnixEthernetTap::updateMulticastGroups(std::set<MulticastGroup> &groups)
+{
+	char *ptr,*ptr2;
+	unsigned char mac[6];
+	std::set<MulticastGroup> newGroups;
+
+	int fd = ::open("/proc/net/dev_mcast",O_RDONLY);
+	if (fd > 0) {
+		char buf[131072];
+		int n = (int)::read(fd,buf,sizeof(buf));
+		if ((n > 0)&&(n < (int)sizeof(buf))) {
+			buf[n] = (char)0;
+			for(char *l=strtok_r(buf,"\r\n",&ptr);(l);l=strtok_r((char *)0,"\r\n",&ptr)) {
+				int fno = 0;
+				char *devname = (char *)0;
+				char *mcastmac = (char *)0;
+				for(char *f=strtok_r(l," \t",&ptr2);(f);f=strtok_r((char *)0," \t",&ptr2)) {
+					if (fno == 1)
+						devname = f;
+					else if (fno == 4)
+						mcastmac = f;
+					++fno;
+				}
+				if ((devname)&&(!strcmp(devname,_dev.c_str()))&&(mcastmac)&&(Utils::unhex(mcastmac,mac,6) == 6))
+					newGroups.insert(MulticastGroup(MAC(mac),0));
+			}
+		}
+		::close(fd);
+	}
+
+	{
+		std::set<InetAddress> allIps(ips());
+		for(std::set<InetAddress>::const_iterator i(allIps.begin());i!=allIps.end();++i)
+			newGroups.insert(MulticastGroup::deriveMulticastGroupForAddressResolution(*i));
+	}
+
+	bool changed = false;
+
+	newGroups.insert(_blindWildcardMulticastGroup); // always join this
+
+	for(std::set<MulticastGroup>::iterator mg(newGroups.begin());mg!=newGroups.end();++mg) {
+		if (!groups.count(*mg)) {
+			groups.insert(*mg);
+			changed = true;
+		}
+	}
+	for(std::set<MulticastGroup>::iterator mg(groups.begin());mg!=groups.end();) {
+		if (!newGroups.count(*mg)) {
+			groups.erase(mg++);
+			changed = true;
+		} else ++mg;
+	}
+
+	return changed;
+}
+#endif // __LINUX__
+
+#ifdef __APPLE__
+// --------------------------------------------------------------------------
+// This source is from:
+// http://www.opensource.apple.com/source/Libinfo/Libinfo-406.17/gen.subproj/getifmaddrs.c?txt
+// It's here because OSX 10.6 does not have this convenience function.
+
+#define	SALIGN	(sizeof(uint32_t) - 1)
+#define	SA_RLEN(sa)	((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : \
+(SALIGN + 1))
+#define	MAX_SYSCTL_TRY	5
+#define	RTA_MASKS	(RTA_GATEWAY | RTA_IFP | RTA_IFA)
+
+/* FreeBSD uses NET_RT_IFMALIST and RTM_NEWMADDR from <sys/socket.h> */
+/* We can use NET_RT_IFLIST2 and RTM_NEWMADDR2 on Darwin */
+//#define DARWIN_COMPAT
+
+//#ifdef DARWIN_COMPAT
+#define GIM_SYSCTL_MIB NET_RT_IFLIST2
+#define GIM_RTM_ADDR RTM_NEWMADDR2
+//#else
+//#define GIM_SYSCTL_MIB NET_RT_IFMALIST
+//#define GIM_RTM_ADDR RTM_NEWMADDR
+//#endif
+
+// Not in 10.6 includes so use our own
+struct _intl_ifmaddrs {
+	struct _intl_ifmaddrs *ifma_next;
+	struct sockaddr *ifma_name;
+	struct sockaddr *ifma_addr;
+	struct sockaddr *ifma_lladdr;
+};
+
+static inline int _intl_getifmaddrs(struct _intl_ifmaddrs **pif)
+{
+	int icnt = 1;
+	int dcnt = 0;
+	int ntry = 0;
+	size_t len;
+	size_t needed;
+	int mib[6];
+	int i;
+	char *buf;
+	char *data;
+	char *next;
+	char *p;
+	struct ifma_msghdr2 *ifmam;
+	struct _intl_ifmaddrs *ifa, *ift;
+	struct rt_msghdr *rtm;
+	struct sockaddr *sa;
+
+	mib[0] = CTL_NET;
+	mib[1] = PF_ROUTE;
+	mib[2] = 0;             /* protocol */
+	mib[3] = 0;             /* wildcard address family */
+	mib[4] = GIM_SYSCTL_MIB;
+	mib[5] = 0;             /* no flags */
+	do {
+		if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
+			return (-1);
+		if ((buf = (char *)malloc(needed)) == NULL)
+			return (-1);
+		if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
+			if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
+				free(buf);
+				return (-1);
+			}
+			free(buf);
+			buf = NULL;
+		} 
+	} while (buf == NULL);
+
+	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
+		rtm = (struct rt_msghdr *)(void *)next;
+		if (rtm->rtm_version != RTM_VERSION)
+			continue;
+		switch (rtm->rtm_type) {
+			case GIM_RTM_ADDR:
+				ifmam = (struct ifma_msghdr2 *)(void *)rtm;
+				if ((ifmam->ifmam_addrs & RTA_IFA) == 0)
+					break;
+				icnt++;
+				p = (char *)(ifmam + 1);
+				for (i = 0; i < RTAX_MAX; i++) {
+					if ((RTA_MASKS & ifmam->ifmam_addrs &
+						 (1 << i)) == 0)
+						continue;
+					sa = (struct sockaddr *)(void *)p;
+					len = SA_RLEN(sa);
+					dcnt += len;
+					p += len;
+				}
+				break;
+		}
+	}
+
+	data = (char *)malloc(sizeof(struct _intl_ifmaddrs) * icnt + dcnt);
+	if (data == NULL) {
+		free(buf);
+		return (-1);
+	}
+
+	ifa = (struct _intl_ifmaddrs *)(void *)data;
+	data += sizeof(struct _intl_ifmaddrs) * icnt;
+
+	memset(ifa, 0, sizeof(struct _intl_ifmaddrs) * icnt);
+	ift = ifa;
+
+	for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
+		rtm = (struct rt_msghdr *)(void *)next;
+		if (rtm->rtm_version != RTM_VERSION)
+			continue;
+
+		switch (rtm->rtm_type) {
+			case GIM_RTM_ADDR:
+				ifmam = (struct ifma_msghdr2 *)(void *)rtm;
+				if ((ifmam->ifmam_addrs & RTA_IFA) == 0)
+					break;
+
+				p = (char *)(ifmam + 1);
+				for (i = 0; i < RTAX_MAX; i++) {
+					if ((RTA_MASKS & ifmam->ifmam_addrs &
+						 (1 << i)) == 0)
+						continue;
+					sa = (struct sockaddr *)(void *)p;
+					len = SA_RLEN(sa);
+					switch (i) {
+						case RTAX_GATEWAY:
+							ift->ifma_lladdr =
+							(struct sockaddr *)(void *)data;
+							memcpy(data, p, len);
+							data += len;
+							break;
+
+						case RTAX_IFP:
+							ift->ifma_name =
+							(struct sockaddr *)(void *)data;
+							memcpy(data, p, len);
+							data += len;
+							break;
+
+						case RTAX_IFA:
+							ift->ifma_addr =
+							(struct sockaddr *)(void *)data;
+							memcpy(data, p, len);
+							data += len;
+							break;
+
+						default:
+							data += len;
+							break;
+					}
+					p += len;
+				}
+				ift->ifma_next = ift + 1;
+				ift = ift->ifma_next;
+				break;
+		}
+	}
+
+	free(buf);
+
+	if (ift > ifa) {
+		ift--;
+		ift->ifma_next = NULL;
+		*pif = ifa;
+	} else {
+		*pif = NULL;
+		free(ifa);
+	}
+	return (0);
+}
+
+static inline void _intl_freeifmaddrs(struct _intl_ifmaddrs *ifmp)
+{
+	free(ifmp);
+}
+
+// --------------------------------------------------------------------------
+
+bool UnixEthernetTap::updateMulticastGroups(std::set<MulticastGroup> &groups)
+{
+	std::set<MulticastGroup> newGroups;
+	struct _intl_ifmaddrs *ifmap = (struct _intl_ifmaddrs *)0;
+	if (!_intl_getifmaddrs(&ifmap)) {
+		struct _intl_ifmaddrs *p = ifmap;
+		while (p) {
+			if (p->ifma_addr->sa_family == AF_LINK) {
+				struct sockaddr_dl *in = (struct sockaddr_dl *)p->ifma_name;
+				struct sockaddr_dl *la = (struct sockaddr_dl *)p->ifma_addr;
+				if ((la->sdl_alen == 6)&&(in->sdl_nlen <= _dev.length())&&(!memcmp(_dev.data(),in->sdl_data,in->sdl_nlen)))
+					newGroups.insert(MulticastGroup(MAC(la->sdl_data + la->sdl_nlen),0));
+			}
+			p = p->ifma_next;
+		}
+		_intl_freeifmaddrs(ifmap);
+	}
+
+	{
+		std::set<InetAddress> allIps(ips());
+		for(std::set<InetAddress>::const_iterator i(allIps.begin());i!=allIps.end();++i)
+			newGroups.insert(MulticastGroup::deriveMulticastGroupForAddressResolution(*i));
+	}
+
+	bool changed = false;
+
+	newGroups.insert(_blindWildcardMulticastGroup); // always join this
+
+	for(std::set<MulticastGroup>::iterator mg(newGroups.begin());mg!=newGroups.end();++mg) {
+		if (!groups.count(*mg)) {
+			groups.insert(*mg);
+			changed = true;
+		}
+	}
+	for(std::set<MulticastGroup>::iterator mg(groups.begin());mg!=groups.end();) {
+		if (!newGroups.count(*mg)) {
+			groups.erase(mg++);
+			changed = true;
+		} else ++mg;
+	}
+
+	return changed;
+}
+#endif // __APPLE__
+
+void UnixEthernetTap::threadMain()
+	throw()
+{
+	fd_set readfds,nullfds;
+	MAC to,from;
+	int n,nfds,r;
+	char getBuf[8194];
+	Buffer<4096> data;
+
+	// Wait for a moment after startup -- wait for Network to finish
+	// constructing itself.
+	Thread::sleep(500);
+
+	FD_ZERO(&readfds);
+	FD_ZERO(&nullfds);
+	nfds = (int)std::max(_shutdownSignalPipe[0],_fd) + 1;
+
+	r = 0;
+	for(;;) {
+		FD_SET(_shutdownSignalPipe[0],&readfds);
+		FD_SET(_fd,&readfds);
+		select(nfds,&readfds,&nullfds,&nullfds,(struct timeval *)0);
+
+		if (FD_ISSET(_shutdownSignalPipe[0],&readfds)) // writes to shutdown pipe terminate thread
+			break;
+
+		if (FD_ISSET(_fd,&readfds)) {
+			n = (int)::read(_fd,getBuf + r,sizeof(getBuf) - r);
+			if (n < 0) {
+				if ((errno != EINTR)&&(errno != ETIMEDOUT)) {
+					TRACE("unexpected error reading from tap: %s",strerror(errno));
+					break;
+				}
+			} else {
+				// Some tap drivers like to send the ethernet frame and the
+				// payload in two chunks, so handle that by accumulating
+				// data until we have at least a frame.
+				r += n;
+				if (r > 14) {
+					if (r > ((int)_mtu + 14)) // sanity check for weird TAP behavior on some platforms
+						r = _mtu + 14;
+					for(int i=0;i<6;++i)
+						to.data[i] = (unsigned char)getBuf[i];
+					for(int i=0;i<6;++i)
+						from.data[i] = (unsigned char)getBuf[i + 6];
+					unsigned int etherType = ntohs(((const uint16_t *)getBuf)[6]);
+					if (etherType != 0x8100) { // VLAN tagged frames are not supported!
+						data.copyFrom(getBuf + 14,(unsigned int)r - 14);
+						_handler(_arg,from,to,etherType,data);
+					}
+					r = 0;
+				}
+			}
+		}
+	}
+}
+
+} // namespace ZeroTier

node/UnixEthernetTap.hpp

@@ -0,0 +1,105 @@
+/*
+ * 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_UNIXETHERNETTAP_HPP
+#define ZT_UNIXETHERNETTAP_HPP
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <stdexcept>
+
+#include "EthernetTap.hpp"
+#include "Mutex.hpp"
+#include "Thread.hpp"
+
+namespace ZeroTier {
+
+class RuntimeEnvironment;
+
+/**
+ * Tap device using Unix taps (contains special case code for Linux, OSX, etc. but they're all similar)
+ */
+class UnixEthernetTap : public EthernetTap
+{
+public:
+	/**
+	 * Construct a new TAP device
+	 *
+	 * Handler arguments: arg,from,to,etherType,data
+	 * 
+	 * @param renv Runtime environment
+	 * @param tryToGetDevice Unix device name (e.g. zt0)
+	 * @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 tap device
+	 */
+	UnixEthernetTap(
+		const RuntimeEnvironment *renv,
+		const char *tryToGetDevice,
+		const MAC &mac,
+		unsigned int mtu,
+		void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
+		void *arg)
+		throw(std::runtime_error);
+
+	virtual ~UnixEthernetTap();
+
+	virtual void setEnabled(bool en);
+	virtual bool enabled() const;
+	virtual void setDisplayName(const char *dn);
+	virtual bool addIP(const InetAddress &ip);
+	virtual bool removeIP(const InetAddress &ip);
+	virtual std::set<InetAddress> ips() const;
+	virtual void put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len);
+	virtual std::string deviceName() const;
+	virtual std::string persistentId() const;
+	virtual bool updateMulticastGroups(std::set<MulticastGroup> &groups);
+
+	/**
+	 * Thread main method; do not call elsewhere
+	 */
+	void threadMain()
+		throw();
+
+private:
+	const RuntimeEnvironment *_r;
+	void (*_handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &);
+	void *_arg;
+	Thread _thread;
+	std::string _dev;
+	int _fd;
+	int _shutdownSignalPipe[2];
+	volatile bool _enabled;
+};
+
+} // namespace ZeroTier
+
+#endif

node/WindowsEthernetTap.hpp

@@ -0,0 +1,273 @@
+/*
+ * 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 persist tap identity at the OS layer (e.g. nwid in hex for Windows or device name for *nix)
+	 * @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

objects.mk

@@ -4,7 +4,6 @@ OBJS=\
 	node/C25519.o \
 	node/CertificateOfMembership.o \
 	node/Defaults.o \
-	node/EthernetTap.o \
 	node/HttpClient.o \
 	node/Identity.o \
 	node/InetAddress.o \
@@ -30,4 +29,5 @@ OBJS=\
 	node/TcpSocket.o \
 	node/Topology.o \
 	node/UdpSocket.o \
+	node/UnixEthernetTap.o \
 	node/Utils.o