Clean up some stuff after new feth tap implementation, and comment agent file.

2 files changed, 798 insertions, 0 deletions

diff --git a/attic/OSXEthernetTap.cpp b/attic/OSXEthernetTap.cpp
new file mode 100644
index 00000000..dbff6200
--- /dev/null
+++ b/attic/OSXEthernetTap.cpp
@@ -0,0 +1,703 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2018  ZeroTier, Inc.  https://www.zerotier.com/
+ *
+ * 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/>.
+ *
+ * --
+ *
+ * You can be released from the requirements of the license by purchasing
+ * a commercial license. Buying such a license is mandatory as soon as you
+ * develop commercial closed-source software that incorporates or links
+ * directly against ZeroTier software without disclosing the source code
+ * of your own application.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <unistd.h>
+#include <signal.h>
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/wait.h>
+#include <sys/select.h>
+#include <sys/cdefs.h>
+#include <sys/uio.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <net/route.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <net/if_dl.h>
+#include <net/if_media.h>
+#include <sys/sysctl.h>
+#include <netinet6/in6_var.h>
+#include <netinet/in_var.h>
+#include <netinet/icmp6.h>
+
+// OSX compile fix... in6_var defines this in a struct which namespaces it for C++ ... why?!?
+struct prf_ra {
+	u_char onlink : 1;
+	u_char autonomous : 1;
+	u_char reserved : 6;
+} prf_ra;
+
+#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
+
+// --------------------------------------------------------------------------
+// --------------------------------------------------------------------------
+// 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);
+}
+
+// --------------------------------------------------------------------------
+// --------------------------------------------------------------------------
+
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+
+#include "../node/Constants.hpp"
+#include "../node/Utils.hpp"
+#include "../node/Mutex.hpp"
+#include "../node/Dictionary.hpp"
+#include "OSUtils.hpp"
+#include "OSXEthernetTap.hpp"
+
+// ff:ff:ff:ff:ff:ff with no ADI
+static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
+
+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;
+}
+
+namespace ZeroTier {
+
+static long globalTapsRunning = 0;
+static Mutex globalTapCreateLock;
+
+OSXEthernetTap::OSXEthernetTap(
+	const char *homePath,
+	const MAC &mac,
+	unsigned int mtu,
+	unsigned int metric,
+	uint64_t nwid,
+	const char *friendlyName,
+	void (*handler)(void *,void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *data,unsigned int len),
+	void *arg) :
+	_handler(handler),
+	_arg(arg),
+	_nwid(nwid),
+	_homePath(homePath),
+	_mtu(mtu),
+	_metric(metric),
+	_fd(0),
+	_enabled(true)
+{
+	char devpath[64],ethaddr[64],mtustr[32],metstr[32],nwids[32];
+	struct stat stattmp;
+
+	OSUtils::ztsnprintf(nwids,sizeof(nwids),"%.16llx",nwid);
+
+	Mutex::Lock _gl(globalTapCreateLock);
+
+	if (::stat("/dev/zt0",&stattmp)) {
+		long kextpid = (long)vfork();
+		if (kextpid == 0) {
+			::chdir(homePath);
+			OSUtils::redirectUnixOutputs("/dev/null",(const char *)0);
+			::execl("/sbin/kextload","/sbin/kextload","-q","-repository",homePath,"tap.kext",(const char *)0);
+			::_exit(-1);
+		} else if (kextpid > 0) {
+			int exitcode = -1;
+			::waitpid(kextpid,&exitcode,0);
+		}
+		::usleep(500); // give tap device driver time to start up and try again
+		if (::stat("/dev/zt0",&stattmp))
+			throw std::runtime_error("/dev/zt# tap devices do not exist and cannot load tap.kext");
+	}
+
+	// Try to reopen the last device we had, if we had one and it's still unused.
+	std::map<std::string,std::string> globalDeviceMap;
+	FILE *devmapf = fopen((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),"r");
+	if (devmapf) {
+		char buf[256];
+		while (fgets(buf,sizeof(buf),devmapf)) {
+			char *x = (char *)0;
+			char *y = (char *)0;
+			char *saveptr = (char *)0;
+			for(char *f=Utils::stok(buf,"\r\n=",&saveptr);(f);f=Utils::stok((char *)0,"\r\n=",&saveptr)) {
+				if (!x) x = f;
+				else if (!y) y = f;
+				else break;
+			}
+			if ((x)&&(y)&&(x[0])&&(y[0]))
+				globalDeviceMap[x] = y;
+		}
+		fclose(devmapf);
+	}
+	bool recalledDevice = false;
+	std::map<std::string,std::string>::const_iterator gdmEntry = globalDeviceMap.find(nwids);
+	if (gdmEntry != globalDeviceMap.end()) {
+		std::string devpath("/dev/"); devpath.append(gdmEntry->second);
+		if (stat(devpath.c_str(),&stattmp) == 0) {
+			_fd = ::open(devpath.c_str(),O_RDWR);
+			if (_fd > 0) {
+				_dev = gdmEntry->second;
+				recalledDevice = true;
+			}
+		}
+	}
+
+	// Open the first unused tap device if we didn't recall a previous one.
+	if (!recalledDevice) {
+		for(int i=0;i<64;++i) {
+			OSUtils::ztsnprintf(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];
+				OSUtils::ztsnprintf(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");
+	}
+
+	// Configure MAC address and MTU, bring interface up
+	OSUtils::ztsnprintf(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]);
+	OSUtils::ztsnprintf(mtustr,sizeof(mtustr),"%u",_mtu);
+	OSUtils::ztsnprintf(metstr,sizeof(metstr),"%u",_metric);
+	long cpid = (long)vfork();
+	if (cpid == 0) {
+		::execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),"lladdr",ethaddr,"mtu",mtustr,"metric",metstr,"up",(const char *)0);
+		::_exit(-1);
+	} else if (cpid > 0) {
+		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);
+
+	// 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);
+
+	++globalTapsRunning;
+
+	globalDeviceMap[nwids] = _dev;
+	devmapf = fopen((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),"w");
+	if (devmapf) {
+		gdmEntry = globalDeviceMap.begin();
+		while (gdmEntry != globalDeviceMap.end()) {
+			fprintf(devmapf,"%s=%s\n",gdmEntry->first.c_str(),gdmEntry->second.c_str());
+			++gdmEntry;
+		}
+		fclose(devmapf);
+	}
+
+	_thread = Thread::start(this);
+}
+
+OSXEthernetTap::~OSXEthernetTap()
+{
+	::write(_shutdownSignalPipe[1],"\0",1); // causes thread to exit
+	Thread::join(_thread);
+
+	::close(_fd);
+	::close(_shutdownSignalPipe[0]);
+	::close(_shutdownSignalPipe[1]);
+
+	{
+		Mutex::Lock _gl(globalTapCreateLock);
+		if (--globalTapsRunning <= 0) {
+			globalTapsRunning = 0; // sanity check -- should not be possible
+
+			char tmp[16384];
+			sprintf(tmp,"%s/%s",_homePath.c_str(),"tap.kext");
+			long kextpid = (long)vfork();
+			if (kextpid == 0) {
+				OSUtils::redirectUnixOutputs("/dev/null",(const char *)0);
+				::execl("/sbin/kextunload","/sbin/kextunload",tmp,(const char *)0);
+				::_exit(-1);
+			} else if (kextpid > 0) {
+				int exitcode = -1;
+				::waitpid(kextpid,&exitcode,0);
+			}
+		}
+	}
+}
+
+void OSXEthernetTap::setEnabled(bool en)
+{
+	_enabled = en;
+	// TODO: interface status change
+}
+
+bool OSXEthernetTap::enabled() const
+{
+	return _enabled;
+}
+
+bool OSXEthernetTap::addIp(const InetAddress &ip)
+{
+	if (!ip)
+		return false;
+
+	long cpid = (long)vfork();
+	if (cpid == 0) {
+		char tmp[128];
+		::execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),(ip.ss_family == AF_INET6) ? "inet6" : "inet",ip.toString(tmp),"alias",(const char *)0);
+		::_exit(-1);
+	} else if (cpid > 0) {
+		int exitcode = -1;
+		::waitpid(cpid,&exitcode,0);
+		return (exitcode == 0);
+	} // else return false...
+
+	return false;
+}
+
+bool OSXEthernetTap::removeIp(const InetAddress &ip)
+{
+	if (!ip)
+		return true;
+	std::vector<InetAddress> allIps(ips());
+	for(std::vector<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i) {
+		if (*i == ip) {
+			long cpid = (long)vfork();
+			if (cpid == 0) {
+				char tmp[128];
+				execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),(ip.ss_family == AF_INET6) ? "inet6" : "inet",ip.toIpString(tmp),"-alias",(const char *)0);
+				_exit(-1);
+			} else if (cpid > 0) {
+				int exitcode = -1;
+				waitpid(cpid,&exitcode,0);
+				return (exitcode == 0);
+			}
+		}
+	}
+	return false;
+}
+
+std::vector<InetAddress> OSXEthernetTap::ips() const
+{
+	struct ifaddrs *ifa = (struct ifaddrs *)0;
+	if (getifaddrs(&ifa))
+		return std::vector<InetAddress>();
+
+	std::vector<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.push_back(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.push_back(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);
+
+	std::sort(r.begin(),r.end());
+	r.erase(std::unique(r.begin(),r.end()),r.end());
+
+	return r;
+}
+
+void OSXEthernetTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
+{
+	char putBuf[ZT_MAX_MTU + 64];
+	if ((_fd > 0)&&(len <= _mtu)&&(_enabled)) {
+		to.copyTo(putBuf,6);
+		from.copyTo(putBuf + 6,6);
+		*((uint16_t *)(putBuf + 12)) = htons((uint16_t)etherType);
+		memcpy(putBuf + 14,data,len);
+		len += 14;
+		::write(_fd,putBuf,len);
+	}
+}
+
+std::string OSXEthernetTap::deviceName() const
+{
+	return _dev;
+}
+
+void OSXEthernetTap::setFriendlyName(const char *friendlyName)
+{
+}
+
+void OSXEthernetTap::scanMulticastGroups(std::vector<MulticastGroup> &added,std::vector<MulticastGroup> &removed)
+{
+	std::vector<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.push_back(MulticastGroup(MAC(la->sdl_data + la->sdl_nlen,6),0));
+			}
+			p = p->ifma_next;
+		}
+		_intl_freeifmaddrs(ifmap);
+	}
+
+	std::vector<InetAddress> allIps(ips());
+	for(std::vector<InetAddress>::iterator ip(allIps.begin());ip!=allIps.end();++ip)
+		newGroups.push_back(MulticastGroup::deriveMulticastGroupForAddressResolution(*ip));
+
+	std::sort(newGroups.begin(),newGroups.end());
+	std::unique(newGroups.begin(),newGroups.end());
+
+	for(std::vector<MulticastGroup>::iterator m(newGroups.begin());m!=newGroups.end();++m) {
+		if (!std::binary_search(_multicastGroups.begin(),_multicastGroups.end(),*m))
+			added.push_back(*m);
+	}
+	for(std::vector<MulticastGroup>::iterator m(_multicastGroups.begin());m!=_multicastGroups.end();++m) {
+		if (!std::binary_search(newGroups.begin(),newGroups.end(),*m))
+			removed.push_back(*m);
+	}
+
+	_multicastGroups.swap(newGroups);
+}
+
+void OSXEthernetTap::setMtu(unsigned int mtu)
+{
+	if (mtu != _mtu) {
+		_mtu = mtu;
+		long cpid = (long)vfork();
+		if (cpid == 0) {
+			char tmp[64];
+			OSUtils::ztsnprintf(tmp,sizeof(tmp),"%u",mtu);
+			execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),"mtu",tmp,(const char *)0);
+			_exit(-1);
+		} else if (cpid > 0) {
+			int exitcode = -1;
+			waitpid(cpid,&exitcode,0);
+		}
+	}
+}
+
+void OSXEthernetTap::threadMain()
+	throw()
+{
+	fd_set readfds,nullfds;
+	MAC to,from;
+	int n,nfds,r;
+	char getBuf[ZT_MAX_MTU + 64];
+
+	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))
+					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;
+
+					if (_enabled) {
+						to.setTo(getBuf,6);
+						from.setTo(getBuf + 6,6);
+						unsigned int etherType = ntohs(((const uint16_t *)getBuf)[6]);
+						// TODO: VLAN support
+						_handler(_arg,(void *)0,_nwid,from,to,etherType,0,(const void *)(getBuf + 14),r - 14);
+					}
+
+					r = 0;
+				}
+			}
+		}
+	}
+}
+
+} // namespace ZeroTier
diff --git a/attic/OSXEthernetTap.hpp b/attic/OSXEthernetTap.hpp
new file mode 100644
index 00000000..fe402901
--- /dev/null
+++ b/attic/OSXEthernetTap.hpp
@@ -0,0 +1,95 @@
+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2018  ZeroTier, Inc.  https://www.zerotier.com/
+ *
+ * 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/>.
+ *
+ * --
+ *
+ * You can be released from the requirements of the license by purchasing
+ * a commercial license. Buying such a license is mandatory as soon as you
+ * develop commercial closed-source software that incorporates or links
+ * directly against ZeroTier software without disclosing the source code
+ * of your own application.
+ */
+
+#ifndef ZT_OSXETHERNETTAP_HPP
+#define ZT_OSXETHERNETTAP_HPP
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+#include "../node/Constants.hpp"
+#include "../node/MAC.hpp"
+#include "../node/InetAddress.hpp"
+#include "../node/MulticastGroup.hpp"
+
+#include "Thread.hpp"
+
+namespace ZeroTier {
+
+/**
+ * OSX Ethernet tap using ZeroTier kernel extension zt# devices
+ */
+class OSXEthernetTap
+{
+public:
+	OSXEthernetTap(
+		const char *homePath,
+		const MAC &mac,
+		unsigned int mtu,
+		unsigned int metric,
+		uint64_t nwid,
+		const char *friendlyName,
+		void (*handler)(void *,void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int),
+		void *arg);
+
+	~OSXEthernetTap();
+
+	void setEnabled(bool en);
+	bool enabled() const;
+	bool addIp(const InetAddress &ip);
+	bool removeIp(const InetAddress &ip);
+	std::vector<InetAddress> ips() const;
+	void put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len);
+	std::string deviceName() const;
+	void setFriendlyName(const char *friendlyName);
+	void scanMulticastGroups(std::vector<MulticastGroup> &added,std::vector<MulticastGroup> &removed);
+	void setMtu(unsigned int mtu);
+
+	void threadMain()
+		throw();
+
+private:
+	void (*_handler)(void *,void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int);
+	void *_arg;
+	uint64_t _nwid;
+	Thread _thread;
+	std::string _homePath;
+	std::string _dev;
+	std::vector<MulticastGroup> _multicastGroups;
+	unsigned int _mtu;
+	unsigned int _metric;
+	int _fd;
+	int _shutdownSignalPipe[2];
+	volatile bool _enabled;
+};
+
+} // namespace ZeroTier
+
+#endif