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ZeroTierOne/node/EthernetTap.cpp

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/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2012-2013 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 <string>
#include <map>
#include <set>
#include <algorithm>
#include "Constants.hpp"
#include "EthernetTap.hpp"
#include "Logger.hpp"
#include "RuntimeEnvironment.hpp"
#include "Utils.hpp"
#include "Mutex.hpp"
#include "Utils.hpp"
// ff:ff:ff:ff:ff:ff with no ADI
static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
//
// TAP implementation for *nix OSes, with some specialization for different flavors
//
#ifdef __UNIX_LIKE__ /////////////////////////////////////////////////////////
#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>
// 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_IPCONFIG_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_IPCONFIG_COMMAND,"ipconfig");
#endif
}
// returns NULL if command was not found
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>
#endif // __LINUX__
#ifdef __APPLE__
#include <sys/uio.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <ifaddrs.h>
#endif // __APPLE__
namespace ZeroTier {
// Only permit one tap to be opened concurrently across the entire process
static Mutex __tapCreateLock;
#ifdef __LINUX__
EthernetTap::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) :
_mac(mac),
_mtu(mtu),
_r(renv),
_handler(handler),
_arg(arg),
_fd(0)
{
char procpath[128];
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));
{ // pick an unused device name
int devno = 0;
struct stat sbuf;
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);
}
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");
}
strcpy(_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);
_thread = Thread::start(this);
}
#endif // __LINUX__
#ifdef __APPLE__
EthernetTap::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) :
_mac(mac),
_mtu(mtu),
_r(renv),
_handler(handler),
_arg(arg),
_dhcp(false),
_dhcp6(false),
_fd(0)
{
char devpath[64],ethaddr[64],mtustr[16];
struct stat tmp;
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",&tmp))&&(kextload)) {
long kextpid;
char tmp[4096];
strcpy(tmp,_r->homePath.c_str());
if ((kextpid = (long)vfork()) == 0) {
chdir(tmp);
execl(kextload,kextload,"-q","-repository",tmp,"tap.kext",(const char *)0);
_exit(-1);
} else {
int exitcode = -1;
waitpid(kextpid,&exitcode,0);
usleep(500);
}
}
if (stat("/dev/zt0",&tmp))
throw std::runtime_error("/dev/zt# tap devices do not exist and unable to load kernel extension");
// Open the first available device (ones in use will fail with resource busy)
for(int i=0;i<256;++i) {
Utils::snprintf(devpath,sizeof(devpath),"/dev/zt%d",i);
if (stat(devpath,&tmp))
throw std::runtime_error("no more TAP devices available");
_fd = ::open(devpath,O_RDWR);
if (_fd > 0) {
Utils::snprintf(_dev,sizeof(_dev),"zt%d",i);
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,"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");
}
}
whack(); // turns on IPv6 on OSX
::pipe(_shutdownSignalPipe);
_thread = Thread::start(this);
}
#endif // __APPLE__
EthernetTap::~EthernetTap()
{
::write(_shutdownSignalPipe[1],"\0",1); // causes thread to exit
Thread::join(_thread);
::close(_fd);
}
#ifdef __APPLE__
void EthernetTap::whack()
{
const char *ipconfig = UNIX_COMMANDS[ZT_MAC_IPCONFIG_COMMAND];
if (ipconfig) {
long cpid = (long)vfork();
if (cpid == 0) {
execl(ipconfig,ipconfig,"set",_dev,"AUTOMATIC-V6",(const char *)0);
_exit(-1);
} else {
int exitcode = -1;
waitpid(cpid,&exitcode,0);
}
}
}
#else
void EthernetTap::whack() {}
#endif // __APPLE__ / !__APPLE__
bool EthernetTap::setDhcpEnabled(bool dhcp)
{
// TODO
return _dhcp;
}
bool EthernetTap::setDhcp6Enabled(bool dhcp)
{
return _dhcp6;
}
void EthernetTap::setDisplayName(const char *dn)
{
}
#ifdef __LINUX__
static bool ___removeIp(const char *_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,(const char *)0);
_exit(-1);
} else {
int exitcode = -1;
waitpid(cpid,&exitcode,0);
return (exitcode == 0);
}
}
bool EthernetTap::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);
return false;
}
Mutex::Lock _l(_ips_m);
if (!ip)
return false;
if (_ips.count(ip) > 0)
return true;
// Remove and reconfigure if address is the same but netmask is different
for(std::set<InetAddress>::iterator i(_ips.begin());i!=_ips.end();++i) {
if (i->ipsEqual(ip)) {
if (___removeIp(_dev,*i)) {
_ips.erase(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,(const char *)0);
_exit(-1);
} else {
int exitcode = -1;
waitpid(cpid,&exitcode,0);
if (exitcode == 0) {
_ips.insert(ip);
return true;
} else return false;
}
return false;
}
#endif // __LINUX__
#ifdef __APPLE__
static bool ___removeIp(const char *_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,"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 EthernetTap::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);
return false;
}
Mutex::Lock _l(_ips_m);
if (!ip)
return false;
if (_ips.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(_ips.begin());i!=_ips.end();++i) {
if ((i->ipsEqual(ip))&&(i->netmaskBits() != ip.netmaskBits())) {
if (___removeIp(_dev,*i)) {
_ips.erase(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,ip.isV4() ? "inet" : "inet6",ip.toString().c_str(),"alias",(const char *)0);
_exit(-1);
} else {
int exitcode = -1;
waitpid(cpid,&exitcode,0);
if (exitcode == 0) {
_ips.insert(ip);
return true;
}
}
return false;
}
#endif // __APPLE__
bool EthernetTap::removeIP(const InetAddress &ip)
{
Mutex::Lock _l(_ips_m);
if (_ips.count(ip) > 0) {
if (___removeIp(_dev,ip)) {
_ips.erase(ip);
return true;
}
}
return false;
}
std::set<InetAddress> EthernetTap::allIps() const
{
// TODO
return ips();
}
void EthernetTap::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,n,len);
}
}
}
std::string EthernetTap::deviceName() const
{
return std::string(_dev);
}
#ifdef __LINUX__
bool EthernetTap::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))&&(mcastmac)&&(Utils::unhex(mcastmac,mac,6) == 6))
newGroups.insert(MulticastGroup(MAC(mac),0));
}
}
::close(fd);
}
{
Mutex::Lock _l(_ips_m);
for(std::set<InetAddress>::const_iterator i(_ips.begin());i!=_ips.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__
bool EthernetTap::updateMulticastGroups(std::set<MulticastGroup> &groups)
{
std::set<MulticastGroup> newGroups;
struct ifmaddrs *ifmap = (struct ifmaddrs *)0;
if (!getifmaddrs(&ifmap)) {
struct 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 <= sizeof(_dev))&&(!memcmp(_dev,in->sdl_data,in->sdl_nlen)))
newGroups.insert(MulticastGroup(MAC(la->sdl_data + la->sdl_nlen),0));
}
p = p->ifma_next;
}
freeifmaddrs(ifmap);
}
{
Mutex::Lock _l(_ips_m);
for(std::set<InetAddress>::const_iterator i(_ips.begin());i!=_ips.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 EthernetTap::threadMain()
throw()
{
fd_set readfds,nullfds;
MAC to,from;
char getBuf[4096 + 14];
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);
int nfds = (int)std::max(_shutdownSignalPipe[0],_fd) + 1;
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)) {
int n = (int)::read(_fd,getBuf,_mtu + 14);
if (n > 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];
data.copyFrom(getBuf + 14,(unsigned int)n - 14);
_handler(_arg,from,to,ntohs(((const uint16_t *)getBuf)[6]),data);
} else if (n < 0) {
if ((errno != EINTR)&&(errno != ETIMEDOUT)) {
TRACE("unexpected error reading from tap: %s",strerror(errno));
break;
}
}
}
}
}
} // namespace ZeroTier
#endif // __UNIX_LIKE__ //////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
#ifdef __WINDOWS__ ///////////////////////////////////////////////////////////
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <WinSock2.h>
#include <Windows.h>
#include <iphlpapi.h>
#include <ws2ipdef.h>
#include <WS2tcpip.h>
#include <tchar.h>
#include <winreg.h>
#include <wchar.h>
#include <nldef.h>
#include <netioapi.h>
#include "..\vsprojects\TapDriver\tap-windows.h"
namespace ZeroTier {
// Helper function to get an adapter's LUID and index from its GUID. The LUID is
// constant but the index can change, so go ahead and just look them both up by
// the GUID which is constant. (The GUID is the instance ID in the registry.)
static inline std::pair<NET_LUID,NET_IFINDEX> _findAdapterByGuid(const GUID &guid)
throw(std::runtime_error)
{
MIB_IF_TABLE2 *ift = (MIB_IF_TABLE2 *)0;
if (GetIfTable2Ex(MibIfTableRaw,&ift) != NO_ERROR)
throw std::runtime_error("GetIfTable2Ex() failed");
for(ULONG i=0;i<ift->NumEntries;++i) {
if (ift->Table[i].InterfaceGuid == guid) {
std::pair<NET_LUID,NET_IFINDEX> tmp(ift->Table[i].InterfaceLuid,ift->Table[i].InterfaceIndex);
FreeMibTable(ift);
return tmp;
}
}
FreeMibTable(&ift);
throw std::runtime_error("interface not found");
}
static Mutex _systemTapInitLock;
EthernetTap::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) :
_mac(mac),
_mtu(mtu),
_r(renv),
_handler(handler),
_arg(arg),
_dhcp(false),
_dhcp6(false),
_tap(INVALID_HANDLE_VALUE),
_injectSemaphore(INVALID_HANDLE_VALUE),
_run(true)
{
char subkeyName[4096];
char subkeyClass[4096];
char data[4096];
if (mtu > ZT_IF_MTU)
throw std::runtime_error("MTU too large for Windows tap");
#ifdef _WIN64
const char *devcon = "\\devcon64.exe";
#else
BOOL f64 = FALSE;
const char *devcon = ((IsWow64Process(GetCurrentProcess(),&f64) == TRUE) ? "\\devcon64.exe" : "\\devcon32.exe");
#endif
Mutex::Lock _l(_systemTapInitLock); // only init one tap at a time, process-wide
HKEY nwAdapters;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,"SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002BE10318}",0,KEY_READ|KEY_WRITE,&nwAdapters) != ERROR_SUCCESS)
throw std::runtime_error("unable to open registry key for network adapter enumeration");
std::set<std::string> existingDeviceInstances;
std::string mySubkeyName;
// Enumerate tap instances and look for one tagged with this tag
for(DWORD subkeyIndex=0;subkeyIndex!=-1;) {
DWORD type;
DWORD dataLen;
DWORD subkeyNameLen = sizeof(subkeyName);
DWORD subkeyClassLen = sizeof(subkeyClass);
FILETIME lastWriteTime;
switch (RegEnumKeyExA(nwAdapters,subkeyIndex++,subkeyName,&subkeyNameLen,(DWORD *)0,subkeyClass,&subkeyClassLen,&lastWriteTime)) {
case ERROR_NO_MORE_ITEMS: subkeyIndex = -1; break;
case ERROR_SUCCESS:
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"ComponentId",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS) {
data[dataLen] = '\0';
if (!strnicmp(data,"zttap",5)) {
std::string instanceId;
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"NetCfgInstanceId",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS) {
instanceId.assign(data,dataLen);
existingDeviceInstances.insert(instanceId);
}
std::string instanceIdPath;
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"DeviceInstanceID",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS)
instanceIdPath.assign(data,dataLen);
if ((_myDeviceInstanceId.length() == 0)&&(instanceId.length() != 0)&&(instanceIdPath.length() != 0)) {
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"_ZeroTierTapIdentifier",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS) {
data[dataLen] = '\0';
if (!strcmp(data,tag)) {
_myDeviceInstanceId = instanceId;
_myDeviceInstanceIdPath = instanceIdPath;
mySubkeyName = subkeyName;
subkeyIndex = -1; // break outer loop
}
}
}
}
}
break;
}
}
// If there is no device, try to create one
if (_myDeviceInstanceId.length() == 0) {
// Execute devcon to install an instance of the Microsoft Loopback Adapter
STARTUPINFOA startupInfo;
startupInfo.cb = sizeof(startupInfo);
PROCESS_INFORMATION processInfo;
memset(&startupInfo,0,sizeof(STARTUPINFOA));
memset(&processInfo,0,sizeof(PROCESS_INFORMATION));
if (!CreateProcessA(NULL,(LPSTR)(std::string("\"") + _r->homePath + devcon + "\" install \"" + _r->homePath + "\\ztTap100.inf\" ztTap100").c_str(),NULL,NULL,FALSE,0,NULL,NULL,&startupInfo,&processInfo)) {
RegCloseKey(nwAdapters);
throw std::runtime_error(std::string("unable to find or execute devcon at ")+devcon);
}
WaitForSingleObject(processInfo.hProcess,INFINITE);
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
// Scan for the new instance by simply looking for taps that weren't
// there originally.
for(DWORD subkeyIndex=0;subkeyIndex!=-1;) {
DWORD type;
DWORD dataLen;
DWORD subkeyNameLen = sizeof(subkeyName);
DWORD subkeyClassLen = sizeof(subkeyClass);
FILETIME lastWriteTime;
switch (RegEnumKeyExA(nwAdapters,subkeyIndex++,subkeyName,&subkeyNameLen,(DWORD *)0,subkeyClass,&subkeyClassLen,&lastWriteTime)) {
case ERROR_NO_MORE_ITEMS: subkeyIndex = -1; break;
case ERROR_SUCCESS:
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"ComponentId",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS) {
data[dataLen] = '\0';
if (!strnicmp(data,"zttap",5)) {
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"NetCfgInstanceId",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS) {
if (existingDeviceInstances.count(std::string(data,dataLen)) == 0) {
RegSetKeyValueA(nwAdapters,subkeyName,"_ZeroTierTapIdentifier",REG_SZ,tag,(DWORD)(strlen(tag)+1));
_myDeviceInstanceId.assign(data,dataLen);
type = 0;
dataLen = sizeof(data);
if (RegGetValueA(nwAdapters,subkeyName,"DeviceInstanceID",RRF_RT_ANY,&type,(PVOID)data,&dataLen) == ERROR_SUCCESS)
_myDeviceInstanceIdPath.assign(data,dataLen);
mySubkeyName = subkeyName;
subkeyIndex = -1; // break outer loop
}
}
}
}
break;
}
}
}
// If we have a device, configure it
if (_myDeviceInstanceId.length() > 0) {
char tmps[4096];
unsigned int tmpsl = Utils::snprintf(tmps,sizeof(tmps),"%.2X-%.2X-%.2X-%.2X-%.2X-%.2X",(unsigned int)mac.data[0],(unsigned int)mac.data[1],(unsigned int)mac.data[2],(unsigned int)mac.data[3],(unsigned int)mac.data[4],(unsigned int)mac.data[5]) + 1;
RegSetKeyValueA(nwAdapters,mySubkeyName.c_str(),"NetworkAddress",REG_SZ,tmps,tmpsl);
RegSetKeyValueA(nwAdapters,mySubkeyName.c_str(),"MAC",REG_SZ,tmps,tmpsl);
DWORD tmp = mtu;
RegSetKeyValueA(nwAdapters,mySubkeyName.c_str(),"MTU",REG_DWORD,(LPCVOID)&tmp,sizeof(tmp));
tmp = 0;
RegSetKeyValueA(nwAdapters,mySubkeyName.c_str(),"EnableDHCP",REG_DWORD,(LPCVOID)&tmp,sizeof(tmp));
}
// Done with registry
RegCloseKey(nwAdapters);
// If we didn't get a device, we can't start
if (_myDeviceInstanceId.length() == 0)
throw std::runtime_error("unable to create new tap adapter");
// Convert device GUID junk... blech
{
char nobraces[128];
const char *nbtmp1 = _myDeviceInstanceId.c_str();
char *nbtmp2 = nobraces;
while (*nbtmp1) {
if ((*nbtmp1 != '{')&&(*nbtmp1 != '}'))
*nbtmp2++ = *nbtmp1;
++nbtmp1;
}
*nbtmp2 = (char)0;
if (UuidFromStringA((RPC_CSTR)nobraces,&_deviceGuid) != RPC_S_OK)
throw std::runtime_error("unable to convert instance ID GUID to native GUID (invalid NetCfgInstanceId in registry?)");
}
setDhcpEnabled(false);
setDhcp6Enabled(false);
// Disable and enable interface to ensure registry settings take effect
{
STARTUPINFOA startupInfo;
startupInfo.cb = sizeof(startupInfo);
PROCESS_INFORMATION processInfo;
memset(&startupInfo,0,sizeof(STARTUPINFOA));
memset(&processInfo,0,sizeof(PROCESS_INFORMATION));
if (!CreateProcessA(NULL,(LPSTR)(std::string("\"") + _r->homePath + devcon + "\" disable @" + _myDeviceInstanceIdPath).c_str(),NULL,NULL,FALSE,0,NULL,NULL,&startupInfo,&processInfo)) {
RegCloseKey(nwAdapters);
throw std::runtime_error(std::string("unable to find or execute devcon at ")+devcon);
}
WaitForSingleObject(processInfo.hProcess,INFINITE);
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
{
STARTUPINFOA startupInfo;
startupInfo.cb = sizeof(startupInfo);
PROCESS_INFORMATION processInfo;
memset(&startupInfo,0,sizeof(STARTUPINFOA));
memset(&processInfo,0,sizeof(PROCESS_INFORMATION));
if (!CreateProcessA(NULL,(LPSTR)(std::string("\"") + _r->homePath + devcon + "\" enable @" + _myDeviceInstanceIdPath).c_str(),NULL,NULL,FALSE,0,NULL,NULL,&startupInfo,&processInfo)) {
RegCloseKey(nwAdapters);
throw std::runtime_error(std::string("unable to find or execute devcon at ")+devcon);
}
WaitForSingleObject(processInfo.hProcess,INFINITE);
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
// Open the tap, which is in this weird Windows analog of /dev
char tapPath[4096];
Utils::snprintf(tapPath,sizeof(tapPath),"\\\\.\\Global\\%s.tap",_myDeviceInstanceId.c_str());
_tap = CreateFileA(tapPath,GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_SYSTEM|FILE_FLAG_OVERLAPPED,NULL);
if (_tap == INVALID_HANDLE_VALUE)
throw std::runtime_error("unable to open tap in \\\\.\\Global\\ namespace");
// Set media status to enabled
uint32_t tmpi = 1;
DWORD bytesReturned = 0;
DeviceIoControl(_tap,TAP_WIN_IOCTL_SET_MEDIA_STATUS,&tmpi,sizeof(tmpi),&tmpi,sizeof(tmpi),&bytesReturned,NULL);
// Initialized overlapped I/O structures and related events
memset(&_tapOvlRead,0,sizeof(_tapOvlRead));
_tapOvlRead.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
memset(&_tapOvlWrite,0,sizeof(_tapOvlWrite));
_tapOvlWrite.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
// Start background thread that actually performs I/O
_injectSemaphore = CreateSemaphore(NULL,0,1,NULL);
_thread = Thread::start(this);
}
EthernetTap::~EthernetTap()
{
_run = false;
ReleaseSemaphore(_injectSemaphore,1,NULL);
Thread::join(_thread);
CloseHandle(_tap);
CloseHandle(_tapOvlRead.hEvent);
CloseHandle(_tapOvlWrite.hEvent);
CloseHandle(_injectSemaphore);
// Disable network device on shutdown
#ifdef _WIN64
const char *devcon = "\\devcon64.exe";
#else
BOOL f64 = FALSE;
const char *devcon = ((IsWow64Process(GetCurrentProcess(),&f64) == TRUE) ? "\\devcon64.exe" : "\\devcon32.exe");
#endif
{
STARTUPINFOA startupInfo;
startupInfo.cb = sizeof(startupInfo);
PROCESS_INFORMATION processInfo;
memset(&startupInfo,0,sizeof(STARTUPINFOA));
memset(&processInfo,0,sizeof(PROCESS_INFORMATION));
if (CreateProcessA(NULL,(LPSTR)(std::string("\"") + _r->homePath + devcon + "\" disable @" + _myDeviceInstanceIdPath).c_str(),NULL,NULL,FALSE,0,NULL,NULL,&startupInfo,&processInfo)) {
WaitForSingleObject(processInfo.hProcess,INFINITE);
CloseHandle(processInfo.hProcess);
CloseHandle(processInfo.hThread);
}
}
}
void EthernetTap::whack()
{
}
bool EthernetTap::setDhcpEnabled(bool dhcp)
{
HKEY tcpIpInterfaces;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,"SYSTEM\\CurrentControlSet\\services\\Tcpip\\Parameters\\Interfaces",0,KEY_READ|KEY_WRITE,&tcpIpInterfaces) == ERROR_SUCCESS) {
_dhcp = dhcp;
DWORD enable = (dhcp ? 1 : 0);
RegSetKeyValueA(tcpIpInterfaces,_myDeviceInstanceId.c_str(),"EnableDHCP",REG_DWORD,&enable,sizeof(enable));
RegCloseKey(tcpIpInterfaces);
} else _dhcp = false;
return _dhcp;
}
bool EthernetTap::setDhcp6Enabled(bool dhcp)
{
// TODO
return _dhcp6;
}
void EthernetTap::setDisplayName(const char *dn)
{
HKEY ifp;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,(std::string("SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}\\") + _myDeviceInstanceId).c_str(),0,KEY_READ|KEY_WRITE,&ifp) == ERROR_SUCCESS) {
RegSetKeyValueA(ifp,"Connection","Name",REG_SZ,(LPCVOID)dn,(DWORD)(strlen(dn)+1));
RegCloseKey(ifp);
}
}
bool EthernetTap::addIP(const InetAddress &ip)
{
Mutex::Lock _l(_ips_m);
if (_ips.count(ip))
return true;
if (!ip.port())
return false;
try {
std::pair<NET_LUID,NET_IFINDEX> ifidx = _findAdapterByGuid(_deviceGuid);
MIB_UNICASTIPADDRESS_ROW ipr;
InitializeUnicastIpAddressEntry(&ipr);
if (ip.isV4()) {
ipr.Address.Ipv4.sin_family = AF_INET;
ipr.Address.Ipv4.sin_addr.S_un.S_addr = *((const uint32_t *)ip.rawIpData());
ipr.OnLinkPrefixLength = ip.port();
} else if (ip.isV6()) {
} else return false;
ipr.PrefixOrigin = IpPrefixOriginManual;
ipr.SuffixOrigin = IpSuffixOriginManual;
ipr.ValidLifetime = 0xffffffff;
ipr.PreferredLifetime = 0xffffffff;
ipr.InterfaceLuid = ifidx.first;
ipr.InterfaceIndex = ifidx.second;
if (CreateUnicastIpAddressEntry(&ipr) == NO_ERROR) {
_ips.insert(ip);
return true;
}
} catch ( ... ) {}
return false;
}
bool EthernetTap::removeIP(const InetAddress &ip)
{
try {
MIB_UNICASTIPADDRESS_TABLE *ipt = (MIB_UNICASTIPADDRESS_TABLE *)0;
std::pair<NET_LUID,NET_IFINDEX> ifidx = _findAdapterByGuid(_deviceGuid);
if (GetUnicastIpAddressTable(AF_UNSPEC,&ipt) == NO_ERROR) {
for(DWORD i=0;i<ipt->NumEntries;++i) {
if ((ipt->Table[i].InterfaceLuid.Value == ifidx.first.Value)&&(ipt->Table[i].InterfaceIndex == ifidx.second)) {
InetAddress addr;
switch(ipt->Table[i].Address.si_family) {
case AF_INET:
addr.set(&(ipt->Table[i].Address.Ipv4.sin_addr.S_un.S_addr),4,ipt->Table[i].OnLinkPrefixLength);
break;
case AF_INET6:
addr.set(ipt->Table[i].Address.Ipv6.sin6_addr.u.Byte,16,ipt->Table[i].OnLinkPrefixLength);
break;
}
if (addr == ip) {
DeleteUnicastIpAddressEntry(&(ipt->Table[i]));
FreeMibTable(ipt);
Mutex::Lock _l(_ips_m);
_ips.erase(ip);
return true;
}
}
}
FreeMibTable(&ipt);
}
} catch ( ... ) {}
return false;
}
std::set<InetAddress> EthernetTap::allIps() const
{
static const InetAddress ifLoopback("fe80::1",64);
std::set<InetAddress> addrs;
try {
MIB_UNICASTIPADDRESS_TABLE *ipt = (MIB_UNICASTIPADDRESS_TABLE *)0;
std::pair<NET_LUID,NET_IFINDEX> ifidx = _findAdapterByGuid(_deviceGuid);
if (GetUnicastIpAddressTable(AF_UNSPEC,&ipt) == NO_ERROR) {
for(DWORD i=0;i<ipt->NumEntries;++i) {
if ((ipt->Table[i].InterfaceLuid.Value == ifidx.first.Value)&&(ipt->Table[i].InterfaceIndex == ifidx.second)) {
switch(ipt->Table[i].Address.si_family) {
case AF_INET:
addrs.insert(InetAddress(&(ipt->Table[i].Address.Ipv4.sin_addr.S_un.S_addr),4,ipt->Table[i].OnLinkPrefixLength));
break;
case AF_INET6: {
InetAddress ip(ipt->Table[i].Address.Ipv6.sin6_addr.u.Byte,16,ipt->Table[i].OnLinkPrefixLength);
if (ip != ifLoopback) // don't include fe80::1
addrs.insert(ip);
} break;
}
}
}
FreeMibTable(ipt);
}
} catch ( ... ) {}
return addrs;
}
void EthernetTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
{
if (len > (ZT_IF_MTU))
return;
{
Mutex::Lock _l(_injectPending_m);
_injectPending.push( std::pair<Array<char,ZT_IF_MTU + 32>,unsigned int>(Array<char,ZT_IF_MTU + 32>(),len + 14) );
char *d = _injectPending.back().first.data;
memcpy(d,to.data,6);
memcpy(d + 6,from.data,6);
*((uint16_t *)(d + 12)) = Utils::hton(etherType);
memcpy(d + 14,data,len);
}
ReleaseSemaphore(_injectSemaphore,1,NULL);
}
std::string EthernetTap::deviceName() const
{
return _myDeviceInstanceId;
}
bool EthernetTap::updateMulticastGroups(std::set<MulticastGroup> &groups)
{
std::set<MulticastGroup> newGroups;
std::set<InetAddress> ipaddrs(allIps());
for(std::set<InetAddress>::const_iterator i(ipaddrs.begin());i!=ipaddrs.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;
}
void EthernetTap::threadMain()
throw()
{
HANDLE wait4[3];
wait4[0] = _injectSemaphore;
wait4[1] = _tapOvlRead.hEvent;
wait4[2] = _tapOvlWrite.hEvent;
ReadFile(_tap,_tapReadBuf,sizeof(_tapReadBuf),NULL,&_tapOvlRead);
bool writeInProgress = false;
for(;;) {
if (!_run) break;
WaitForMultipleObjectsEx(3,wait4,FALSE,INFINITE,TRUE);
if (!_run) break;
if (HasOverlappedIoCompleted(&_tapOvlRead)) {
DWORD bytesRead = 0;
if (GetOverlappedResult(_tap,&_tapOvlRead,&bytesRead,FALSE)) {
if (bytesRead > 14) {
MAC to(_tapReadBuf);
MAC from(_tapReadBuf + 6);
unsigned int etherType = Utils::ntoh(*((const uint16_t *)(_tapReadBuf + 12)));
Buffer<4096> tmp(_tapReadBuf + 14,bytesRead - 14);
//printf("GOT FRAME: %u bytes: %s\r\n",(unsigned int)bytesRead,Utils::hex(_tapReadBuf,bytesRead).c_str());
_handler(_arg,from,to,etherType,tmp);
}
}
ReadFile(_tap,_tapReadBuf,sizeof(_tapReadBuf),NULL,&_tapOvlRead);
}
if (writeInProgress) {
if (HasOverlappedIoCompleted(&_tapOvlWrite)) {
writeInProgress = false;
_injectPending_m.lock();
_injectPending.pop();
} else continue; // still writing, so skip code below and wait
} else _injectPending_m.lock();
if (!_injectPending.empty()) {
WriteFile(_tap,_injectPending.front().first.data,_injectPending.front().second,NULL,&_tapOvlWrite);
writeInProgress = true;
}
_injectPending_m.unlock();
}
CancelIo(_tap);
}
} // namespace ZeroTier
#endif // __WINDOWS__ ////////////////////////////////////////////////////////
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