summaryrefslogtreecommitdiff
path: root/osnet/BSDEthernetTap.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'osnet/BSDEthernetTap.cpp')
-rw-r--r--osnet/BSDEthernetTap.cpp429
1 files changed, 429 insertions, 0 deletions
diff --git a/osnet/BSDEthernetTap.cpp b/osnet/BSDEthernetTap.cpp
new file mode 100644
index 00000000..100fb171
--- /dev/null
+++ b/osnet/BSDEthernetTap.cpp
@@ -0,0 +1,429 @@
+/*
+ * 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 <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/sysctl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <ifaddrs.h>
+#include <net/if_arp.h>
+#include <net/if_dl.h>
+#include <net/if_media.h>
+#include <net/route.h>
+
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+
+#include "../node/Constants.hpp"
+#include "../node/Utils.hpp"
+#include "../node/Mutex.hpp"
+#include "BSDEthernetTap.hpp"
+
+#define ZT_BASE32_CHARS "0123456789abcdefghijklmnopqrstuv"
+
+// ff:ff:ff:ff:ff:ff with no ADI
+static const ZeroTier::MulticastGroup _blindWildcardMulticastGroup(ZeroTier::MAC(0xff),0);
+
+namespace ZeroTier {
+
+BSDEthernetTap::BSDEthernetTap(
+ 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) :
+ EthernetTap("BSDEthernetTap",mac,mtu,metric),
+ _handler(handler),
+ _arg(arg),
+ _mtu(mtu),
+ _metric(metric),
+ _fd(0),
+ _enabled(true)
+{
+ static Mutex globalTapCreateLock;
+ char devpath[64],ethaddr[64],mtustr[32],metstr[32],tmpdevname[32];
+ struct stat stattmp;
+
+ // On FreeBSD at least we can rename, so use nwid to generate a deterministic unique zt#### name using base32
+ // As a result we don't use desiredDevice
+ _dev = "zt";
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 60) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 55) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 50) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 45) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 40) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 35) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 30) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 25) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 20) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 15) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 10) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)((nwid >> 5) & 0x1f)]);
+ _dev.push_back(ZT_BASE32_CHARS[(unsigned long)(nwid & 0x1f)]);
+
+ Mutex::Lock _gl(globalTapCreateLock);
+
+ if (mtu > 2800)
+ throw std::runtime_error("max tap MTU is 2800");
+
+ // On BSD we create taps and they can have high numbers, so use ones starting
+ // at 9993 to not conflict with other stuff. Then we rename it to zt<base32 of nwid>
+ std::map<std::string,bool> devFiles(Utils::listDirectory("/dev"));
+ for(int i=9993;i<(9993+128);++i) {
+ Utils::snprintf(tmpdevname,sizeof(tmpdevname),"tap%d",i);
+ Utils::snprintf(devpath,sizeof(devpath),"/dev/%s",tmpdevname);
+ if (devFiles.count(std::string(tmpdevname)) == 0) {
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ ::execl("/sbin/ifconfig","/sbin/ifconfig",tmpdevname,"create",(const char *)0);
+ ::_exit(-1);
+ } else if (cpid > 0) {
+ int exitcode = -1;
+ ::waitpid(cpid,&exitcode,0);
+ } else throw std::runtime_error("fork() failed");
+
+ if (!stat(devpath,&stattmp)) {
+ cpid = (long)vfork();
+ if (cpid == 0) {
+ ::execl("/sbin/ifconfig","/sbin/ifconfig",tmpdevname,"name",_dev.c_str(),(const char *)0);
+ ::_exit(-1);
+ } else if (cpid > 0) {
+ int exitcode = -1;
+ ::waitpid(cpid,&exitcode,0);
+ if (exitcode)
+ throw std::runtime_error("ifconfig rename operation failed");
+ } else throw std::runtime_error("fork() failed");
+
+ _fd = ::open(devpath,O_RDWR);
+ if (_fd > 0)
+ break;
+ else throw std::runtime_error("unable to open created tap device");
+ } else {
+ throw std::runtime_error("cannot find /dev node for newly created tap device");
+ }
+ }
+ }
+
+ 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
+ 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);
+ Utils::snprintf(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");
+ }
+ }
+
+ // 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);
+
+ _thread = Thread::start(this);
+}
+
+BSDEthernetTap::~BSDEthernetTap()
+{
+ ::write(_shutdownSignalPipe[1],"\0",1); // causes thread to exit
+ Thread::join(_thread);
+ ::close(_fd);
+ ::close(_shutdownSignalPipe[0]);
+ ::close(_shutdownSignalPipe[1]);
+
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ ::execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),"destroy",(const char *)0);
+ ::_exit(-1);
+ } else if (cpid > 0) {
+ int exitcode = -1;
+ ::waitpid(cpid,&exitcode,0);
+ }
+}
+
+void BSDEthernetTap::setEnabled(bool en)
+{
+ _enabled = en;
+ // TODO: interface status change
+}
+
+bool BSDEthernetTap::enabled() const
+{
+ return _enabled;
+}
+
+static bool ___removeIp(const std::string &_dev,const InetAddress &ip)
+{
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),"inet",ip.toIpString().c_str(),"-alias",(const char *)0);
+ _exit(-1);
+ } else if (cpid > 0) {
+ int exitcode = -1;
+ waitpid(cpid,&exitcode,0);
+ return (exitcode == 0);
+ }
+ return false; // never reached, make compiler shut up about return value
+}
+
+bool BSDEthernetTap::addIP(const InetAddress &ip)
+{
+ if (!ip)
+ return false;
+
+ std::set<InetAddress> allIps(ips());
+ if (allIps.count(ip) > 0)
+ return true; // IP/netmask already assigned
+
+ // Remove and reconfigure if address is the same but netmask is different
+ for(std::set<InetAddress>::iterator i(allIps.begin());i!=allIps.end();++i) {
+ if ((i->ipsEqual(ip))&&(i->netmaskBits() != ip.netmaskBits())) {
+ if (___removeIp(_dev,*i))
+ break;
+ }
+ }
+
+ long cpid = (long)vfork();
+ if (cpid == 0) {
+ ::execl("/sbin/ifconfig","/sbin/ifconfig",_dev.c_str(),ip.isV4() ? "inet" : "inet6",ip.toString().c_str(),"alias",(const char *)0);
+ ::_exit(-1);
+ } else if (cpid > 0) {
+ int exitcode = -1;
+ ::waitpid(cpid,&exitcode,0);
+ return (exitcode == 0);
+ }
+ return false;
+}
+
+bool BSDEthernetTap::removeIP(const InetAddress &ip)
+{
+ if (ips().count(ip) > 0) {
+ if (___removeIp(_dev,ip))
+ return true;
+ }
+ return false;
+}
+
+std::set<InetAddress> BSDEthernetTap::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 BSDEthernetTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
+{
+ char putBuf[4096];
+ 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 BSDEthernetTap::deviceName() const
+{
+ return _dev;
+}
+
+void BSDEthernetTap::setFriendlyName(const char *friendlyName)
+{
+}
+
+bool BSDEthernetTap::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 <= _dev.length())&&(!memcmp(_dev.data(),in->sdl_data,in->sdl_nlen)))
+ newGroups.insert(MulticastGroup(MAC(la->sdl_data + la->sdl_nlen,6),0));
+ }
+ p = p->ifma_next;
+ }
+ freeifmaddrs(ifmap);
+ }
+
+ {
+ std::set<InetAddress> allIps(ips());
+ for(std::set<InetAddress>::const_iterator i(allIps.begin());i!=allIps.end();++i)
+ newGroups.insert(MulticastGroup::deriveMulticastGroupForAddressResolution(*i));
+ }
+
+ bool changed = false;
+
+ 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;
+}
+
+bool BSDEthernetTap::injectPacketFromHost(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len)
+{
+ return false;
+}
+
+void BSDEthernetTap::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))
+ 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]);
+ data.copyFrom(getBuf + 14,(unsigned int)r - 14);
+ _handler(_arg,from,to,etherType,data);
+ }
+
+ r = 0;
+ }
+ }
+ }
+ }
+}
+
+} // namespace ZeroTier
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-25 15:53:35 +0000