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-rw-r--r--zto/osdep/LinuxEthernetTap.cpp483
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diff --git a/zto/osdep/LinuxEthernetTap.cpp b/zto/osdep/LinuxEthernetTap.cpp
new file mode 100644
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+++ b/zto/osdep/LinuxEthernetTap.cpp
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+/*
+ * ZeroTier One - Network Virtualization Everywhere
+ * Copyright (C) 2011-2016 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/>.
+ */
+
+#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 <algorithm>
+#include <utility>
+
+#include "../node/Constants.hpp"
+#include "../node/Utils.hpp"
+#include "../node/Mutex.hpp"
+#include "../node/Dictionary.hpp"
+#include "OSUtils.hpp"
+#include "LinuxEthernetTap.hpp"
+
+// ff:ff:ff:ff:ff:ff with no ADI
+static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
+
+namespace ZeroTier {
+
+static Mutex __tapCreateLock;
+
+LinuxEthernetTap::LinuxEthernetTap(
+ const char *homePath,
+ const MAC &mac,
+ unsigned int mtu,
+ unsigned int metric,
+ uint64_t nwid,
+ const char *friendlyName,
+ void (*handler)(void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int),
+ void *arg) :
+ _handler(handler),
+ _arg(arg),
+ _nwid(nwid),
+ _homePath(homePath),
+ _mtu(mtu),
+ _fd(0),
+ _enabled(true)
+{
+ char procpath[128],nwids[32];
+ struct stat sbuf;
+
+ Utils::snprintf(nwids,sizeof(nwids),"%.16llx",nwid);
+
+ Mutex::Lock _l(__tapCreateLock); // create only one tap at a time, globally
+
+ if (mtu > 2800)
+ throw std::runtime_error("max tap MTU is 2800");
+
+ _fd = ::open("/dev/net/tun",O_RDWR);
+ if (_fd <= 0) {
+ _fd = ::open("/dev/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;
+ std::string devmapbuf;
+ Dictionary<8194> devmap;
+ if (OSUtils::readFile((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),devmapbuf)) {
+ devmap.load(devmapbuf.c_str());
+ char desiredDevice[128];
+ if (devmap.get(nwids,desiredDevice,sizeof(desiredDevice)) > 0) {
+ Utils::scopy(ifr.ifr_name,sizeof(ifr.ifr_name),desiredDevice);
+ 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 {
+#ifdef __SYNOLOGY__
+ devno+=50; // Arbitrary number to prevent interface name conflicts
+ Utils::snprintf(ifr.ifr_name,sizeof(ifr.ifr_name),"eth%d",devno++);
+#else
+ Utils::snprintf(ifr.ifr_name,sizeof(ifr.ifr_name),"zt%d",devno++);
+#endif
+ 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);
+
+ (void)::pipe(_shutdownSignalPipe);
+
+ devmap.erase(nwids);
+ devmap.add(nwids,_dev.c_str());
+ OSUtils::writeFile((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),(const void *)devmap.data(),devmap.sizeBytes());
+
+ _thread = Thread::start(this);
+}
+
+LinuxEthernetTap::~LinuxEthernetTap()
+{
+ (void)::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;
+}
+
+bool LinuxEthernetTap::enabled() const
+{
+ return _enabled;
+}
+
+static bool ___removeIp(const std::string &_dev,const InetAddress &ip)
+{
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ OSUtils::redirectUnixOutputs("/dev/null",(const char *)0);
+ setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
+ ::execlp("ip","ip","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);
+ }
+}
+
+#ifdef __SYNOLOGY__
+bool LinuxEthernetTap::addIpSyn(std::vector<InetAddress> ips)
+{
+ // Here we fill out interface config (ifcfg-dev) to prevent it from being killed
+ std::string filepath = "/etc/sysconfig/network-scripts/ifcfg-"+_dev;
+ std::string cfg_contents = "DEVICE="+_dev+"\nBOOTPROTO=static";
+ int ip4=0,ip6=0,ip4_tot=0,ip6_tot=0;
+
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ OSUtils::redirectUnixOutputs("/dev/null",(const char *)0);
+ setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
+ // We must know if there is at least (one) of each protocol version so we
+ // can properly enumerate address/netmask combinations in the ifcfg-dev file
+ for(int i=0; i<(int)ips.size(); i++) {
+ if (ips[i].isV4())
+ ip4_tot++;
+ else
+ ip6_tot++;
+ }
+ // Assemble and write contents of ifcfg-dev file
+ for(int i=0; i<(int)ips.size(); i++) {
+ if (ips[i].isV4()) {
+ std::string numstr4 = ip4_tot > 1 ? std::to_string(ip4) : "";
+ cfg_contents += "\nIPADDR"+numstr4+"="+ips[i].toIpString()
+ + "\nNETMASK"+numstr4+"="+ips[i].netmask().toIpString()+"\n";
+ ip4++;
+ }
+ else {
+ std::string numstr6 = ip6_tot > 1 ? std::to_string(ip6) : "";
+ cfg_contents += "\nIPV6ADDR"+numstr6+"="+ips[i].toIpString()
+ + "\nNETMASK"+numstr6+"="+ips[i].netmask().toIpString()+"\n";
+ ip6++;
+ }
+ }
+ OSUtils::writeFile(filepath.c_str(), cfg_contents.c_str(), cfg_contents.length());
+ // Finaly, add IPs
+ for(int i=0; i<(int)ips.size(); i++){
+ if (ips[i].isV4())
+ ::execlp("ip","ip","addr","add",ips[i].toString().c_str(),"broadcast",ips[i].broadcast().toIpString().c_str(),"dev",_dev.c_str(),(const char *)0);
+ else
+ ::execlp("ip","ip","addr","add",ips[i].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 true;
+}
+#endif // __SYNOLOGY__
+
+bool LinuxEthernetTap::addIp(const InetAddress &ip)
+{
+ if (!ip)
+ return false;
+
+ std::vector<InetAddress> allIps(ips());
+ if (std::binary_search(allIps.begin(),allIps.end(),ip))
+ return true;
+
+ // Remove and reconfigure if address is the same but netmask is different
+ for(std::vector<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i) {
+ if (i->ipsEqual(ip))
+ ___removeIp(_dev,*i);
+ }
+
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ OSUtils::redirectUnixOutputs("/dev/null",(const char *)0);
+ setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
+ if (ip.isV4()) {
+ ::execlp("ip","ip","addr","add",ip.toString().c_str(),"broadcast",ip.broadcast().toIpString().c_str(),"dev",_dev.c_str(),(const char *)0);
+ } else {
+ ::execlp("ip","ip","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 (!ip)
+ return true;
+ std::vector<InetAddress> allIps(ips());
+ if (std::find(allIps.begin(),allIps.end(),ip) != allIps.end()) {
+ if (___removeIp(_dev,ip))
+ return true;
+ }
+ return false;
+}
+
+std::vector<InetAddress> LinuxEthernetTap::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 LinuxEthernetTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
+{
+ char putBuf[8194];
+ 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;
+ (void)::write(_fd,putBuf,len);
+ }
+}
+
+std::string LinuxEthernetTap::deviceName() const
+{
+ return _dev;
+}
+
+void LinuxEthernetTap::setFriendlyName(const char *friendlyName)
+{
+}
+
+void LinuxEthernetTap::scanMulticastGroups(std::vector<MulticastGroup> &added,std::vector<MulticastGroup> &removed)
+{
+ char *ptr,*ptr2;
+ unsigned char mac[6];
+ std::vector<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.push_back(MulticastGroup(MAC(mac,6),0));
+ }
+ }
+ ::close(fd);
+ }
+
+ 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());
+ newGroups.erase(std::unique(newGroups.begin(),newGroups.end()),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 LinuxEthernetTap::threadMain()
+ throw()
+{
+ fd_set readfds,nullfds;
+ MAC to,from;
+ int n,nfds,r;
+ char getBuf[8194];
+
+ 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,_nwid,from,to,etherType,0,(const void *)(getBuf + 14),r - 14);
+ }
+
+ r = 0;
+ }
+ }
+ }
+ }
+}
+
+} // namespace ZeroTier
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