Split UnixEthernetTap by platform to get rid of ifdef spaghetti.

node/EthernetTap.hpp

@@ -70,15 +70,6 @@ public:
 	 */
 	virtual bool enabled() const = 0;
 
-	/**
-	 * Set the user display name for this connection
-	 *
-	 * This does nothing on platforms that don't have this concept.
-	 *
-	 * @param dn User display name
-	 */
-	virtual void setDisplayName(const char *dn) = 0;
-
 	/**
 	 * @return MAC address of this interface
 	 */
@@ -89,6 +80,11 @@ public:
 	 */
 	inline unsigned int mtu() const throw() { return _mtu; }
 
+	/**
+	 * @return Interface metric
+	 */
+	inline unsigned int metric() const throw() { return _metric; }
+
 	/**
 	 * Add an IP to this interface
 	 *
@@ -192,14 +188,16 @@ public:
 	virtual bool updateMulticastGroups(std::set<MulticastGroup> &groups) = 0;
 
 protected:
-	EthernetTap(const char *cn,const MAC &m,unsigned int mt) :
+	EthernetTap(const char *cn,const MAC &m,unsigned int mt,unsigned int met) :
 		_implName(cn),
 		_mac(m),
-		_mtu(mt) {}
+		_mtu(mt),
+		_metric(met) {}
 
 	const char *_implName;
 	MAC _mac;
 	unsigned int _mtu;
+	unsigned int _metric;
 };
 
 } // namespace ZeroTier

node/EthernetTapFactory.hpp

@@ -30,6 +30,8 @@
 
 #include <stdint.h>
 
+#include <stdexcept>
+
 #include "MAC.hpp"
 
 namespace ZeroTier {
@@ -58,15 +60,36 @@ public:
 	 *
 	 * On some platforms (Windows) this can be a time-consuming operation.
 	 *
+	 * Note that close() must be used. Do not just delete the tap instance,
+	 * since this may leave orphaned resources or cause other problems.
+	 *
 	 * @param mac MAC address
 	 * @param mtu Device MTU
 	 * @param metric Interface metric (higher = lower priority, may not be supported on all OSes)
 	 * @param nwid ZeroTier network ID
 	 * @param desiredDevice Desired system device name or NULL for no preference
 	 * @param friendlyName Friendly name of this interface or NULL for none (not used on all platforms)
-	 * @return EthernetTap instance or NULL on failure
+	 * @param handler Function to call when packets are received
+	 * @param arg First argument to provide to handler
+	 * @return EthernetTap instance
+	 * @throws std::runtime_error Unable to initialize tap device
 	 */
-	virtual EthernetTap *get(const MAC &mac,unsigned int mtu,unsigned int metric,uint64_t nwid,const char *desiredDevice,const char *friendlyName) = 0;
+	virtual EthernetTap *open(
+		const MAC &mac,
+		unsigned int mtu,
+		unsigned int metric,
+		uint64_t nwid,
+		const char *desiredDevice,
+		const char *friendlyName,
+		void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
+		void *arg) = 0;
+
+	/**
+	 * Close an ethernet tap device
+	 *
+	 * @param tap Tap instance
+	 */
+	virtual void close(EthernetTap *tap) = 0;
 };
 
 } // namespace ZeroTier

node/osdep/LinuxEthernetTap.cpp

@@ -0,0 +1,482 @@
+/*
+ * 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 <linux/if.h>
+#include <linux/if_tun.h>
+#include <linux/if_addr.h>
+#include <linux/if_ether.h>
+#include <ifaddrs.h>
+
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+
+#include "../Constants.hpp"
+#include "../Utils.hpp"
+#include "../Mutex.hpp"
+#include "LinuxEthernetTap.hpp"
+
+// ff:ff:ff:ff:ff:ff with no ADI
+static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
+
+// On startup, searches the path for required external utilities (which might vary by Linux distro)
+#define ZT_UNIX_IP_COMMAND 1
+class _CommandFinder
+{
+public:
+	_CommandFinder()
+	{
+		_findCmd(ZT_UNIX_IP_COMMAND,"ip");
+	}
+	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;
+
+namespace ZeroTier {
+
+// Only permit one tap to be opened concurrently across the entire process
+static Mutex __tapCreateLock;
+
+LinuxEthernetTap::LinuxEthernetTap(
+	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("LinuxEthernetTap",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;
+	mac.copyTo(ifr.ifr_ifru.ifru_hwaddr.sa_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);
+
+	// Set close-on-exec so that devices cannot persist if we fork/exec for update
+	fcntl(_fd,F_SETFD,fcntl(_fd,F_GETFD) | FD_CLOEXEC);
+
+	::pipe(_shutdownSignalPipe);
+
+	TRACE("tap %s created",_dev.c_str());
+
+	_thread = Thread::start(this);
+}
+
+LinuxEthernetTap::~LinuxEthernetTap()
+{
+	::write(_shutdownSignalPipe[1],"\0",1); // causes thread to exit
+	Thread::join(_thread);
+	::close(_fd);
+	::close(_shutdownSignalPipe[0]);
+	::close(_shutdownSignalPipe[1]);
+}
+
+void LinuxEthernetTap::setEnabled(bool en)
+{
+	_enabled = en;
+	// TODO: interface status change
+}
+
+bool LinuxEthernetTap::enabled() const
+{
+	return _enabled;
+}
+
+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 LinuxEthernetTap::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;
+}
+
+bool LinuxEthernetTap::removeIP(const InetAddress &ip)
+{
+	if (ips().count(ip) > 0) {
+		if (___removeIp(_dev,ip))
+			return true;
+	}
+	return false;
+}
+
+std::set<InetAddress> LinuxEthernetTap::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 LinuxEthernetTap::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)) {
+		to.copyTo(putBuf,6);
+		from.copyTo(putBuf + 6,6);
+		*((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 LinuxEthernetTap::deviceName() const
+{
+	return _dev;
+}
+
+std::string LinuxEthernetTap::persistentId() const
+{
+	return std::string();
+}
+
+bool LinuxEthernetTap::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,6),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;
+
+	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))&&(*mg != _blindWildcardMulticastGroup)) {
+			groups.erase(mg++);
+			changed = true;
+		} else ++mg;
+	}
+
+	return changed;
+}
+
+void LinuxEthernetTap::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;
+					to.setTo(getBuf,6);
+					from.setTo(getBuf + 6,6);
+					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/osdep/LinuxEthernetTap.hpp

@@ -25,56 +25,40 @@
  * LLC. Start here: http://www.zerotier.com/
  */
 
-#ifndef ZT_UNIXETHERNETTAP_HPP
-#define ZT_UNIXETHERNETTAP_HPP
+#ifndef ZT_LINUXETHERNETTAP_HPP
+#define ZT_LINUXETHERNETTAP_HPP
 
 #include <stdio.h>
 #include <stdlib.h>
 
 #include <stdexcept>
 
-#include "EthernetTap.hpp"
-#include "Mutex.hpp"
-#include "Thread.hpp"
+#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)
+ * Linux Ethernet tap using kernel tun/tap driver
  */
-class UnixEthernetTap : public EthernetTap
+class LinuxEthernetTap : 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,
+	LinuxEthernetTap(
 		const MAC &mac,
 		unsigned int mtu,
+		unsigned int metric,
+		uint64_t nwid,
+		const char *desiredDevice,
+		const char *friendlyName,
 		void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
-		void *arg)
-		throw(std::runtime_error);
+		void *arg);
 
-	virtual ~UnixEthernetTap();
+	virtual ~LinuxEthernetTap();
 
 	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;
@@ -83,14 +67,10 @@ public:
 	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;

node/osdep/OSXEthernetTap.hpp

@@ -0,0 +1,89 @@
+/*
+ * 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_OSXETHERNETTAP_HPP
+#define ZT_OSXETHERNETTAP_HPP
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <stdexcept>
+
+#include "../EthernetTap.hpp"
+#include "../Mutex.hpp"
+#include "../Thread.hpp"
+
+namespace ZeroTier {
+
+/**
+ * OSX Ethernet tap using ZeroTier kernel extension zt# devices
+ *
+ * This also installs a friendly-named network device in the system network
+ * configuration, permitting network devices to be seen and configured in
+ * the OSX system preferences app.
+ */
+class OSXEthernetTap : public EthernetTap
+{
+public:
+	OSXEthernetTap(
+		const MAC &mac,
+		unsigned int mtu,
+		unsigned int metric,
+		uint64_t nwid,
+		const char *desiredDevice,
+		const char *friendlyName,
+		void (*handler)(void *,const MAC &,const MAC &,unsigned int,const Buffer<4096> &),
+		void *arg);
+
+	virtual ~OSXEthernetTap();
+
+	virtual void setEnabled(bool en);
+	virtual bool enabled() const;
+	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);
+
+	void threadMain()
+		throw();
+
+private:
+	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