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7475c4047e
ZeroTierOne/node/osdep/OSXEthernetTap.cpp
Adam Ierymenko 7475c4047e A bunch more osdep/ work...
2014-07-23 09:14:53 -07:00

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/*
* 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/route.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <netinet6/in6_var.h>
#include <netinet/in_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <ifaddrs.h>
// OSX compile fix... in6_var defines this in a struct which namespaces it for C++
struct prf_ra {
u_char onlink : 1;
u_char autonomous : 1;
u_char reserved : 6;
} prf_ra;
// 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 "../Constants.hpp"
#include "../Utils.hpp"
#include "../Mutex.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 {
// Only permit one tap to be opened concurrently across the entire process
static Mutex __tapCreateLock;
OSXEthernetTap::OSXEthernetTap(
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("OSXEthernetTap",mac,mtu,metric),
_r(renv),
_handler(handler),
_arg(arg),
_fd(0),
_enabled(true)
{
char devpath[64],ethaddr[64],mtustr[32],metstr[32];
struct stat stattmp;
Mutex::Lock _l(__tapCreateLock); // create only one tap at a time, globally
if (mtu > 2800)
throw std::runtime_error("max tap MTU is 2800");
if (stat("/dev/zt0",&stattmp))
throw std::runtime_error("/dev/zt# tap devices do not exist and unable to load kernel extension");
// Try to reopen the last device we had, if we had one and it's still unused.
bool recalledDevice = false;
if ((tryToGetDevice)&&(tryToGetDevice[0])) {
Utils::snprintf(devpath,sizeof(devpath),"/dev/%s",tryToGetDevice);
if (stat(devpath,&stattmp) == 0) {
_fd = ::open(devpath,O_RDWR);
if (_fd > 0) {
_dev = tryToGetDevice;
recalledDevice = true;
}
}
}
// Open the first unused tap device if we didn't recall a previous one.
if (!recalledDevice) {
for(int i=0;i<256;++i) {
Utils::snprintf(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];
Utils::snprintf(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
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");
}
}
_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);
_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]);
}
void OSXEthernetTap::setEnabled(bool en)
{
_enabled = en;
// TODO: interface status change
}
bool OSXEthernetTap::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 (cpid > 0) {
int exitcode = -1;
waitpid(cpid,&exitcode,0);
return (exitcode == 0);
}
return false; // never reached, make compiler shut up about return value
}
bool OSXEthernetTap::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;
} else {
LOG("WARNING: failed to remove old IP/netmask %s to replace with %s",i->toString().c_str(),ip.toString().c_str());
}
}
}
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 OSXEthernetTap::removeIP(const InetAddress &ip)
{
if (ips().count(ip) > 0) {
if (___removeIp(_dev,ip))
return true;
}
return false;
}
std::set<InetAddress> OSXEthernetTap::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 OSXEthernetTap::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 OSXEthernetTap::deviceName() const
{
return _dev;
}
std::string OSXEthernetTap::persistentId() const
{
return std::string();
}
bool OSXEthernetTap::updateMulticastGroups(std::set<MulticastGroup> &groups)
{
std::set<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.insert(MulticastGroup(MAC(la->sdl_data + la->sdl_nlen,6),0));
}
p = p->ifma_next;
}
_intl_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;
}
void OSXEthernetTap::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
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