/*
* 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/>.
*/
#ifndef ZT_BINDER_HPP
#define ZT_BINDER_HPP
#include "../node/Constants.hpp"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef __WINDOWS__
#include <WinSock2.h>
#include <Windows.h>
#include <ShlObj.h>
#include <netioapi.h>
#include <iphlpapi.h>
#else
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <ifaddrs.h>
#ifdef __LINUX__
#include <sys/ioctl.h>
#include <net/if.h>
#endif
#endif
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <map>
#include "../node/NonCopyable.hpp"
#include "../node/InetAddress.hpp"
#include "../node/Mutex.hpp"
#include "../node/Utils.hpp"
#include "Phy.hpp"
#include "OSUtils.hpp"
/**
* Period between binder rescans/refreshes
*
* OneService also does this on detected restarts.
*/
#define ZT_BINDER_REFRESH_PERIOD 30000
namespace ZeroTier {
/**
* Enumerates local devices and binds to all potential ZeroTier path endpoints
*
* This replaces binding to wildcard (0.0.0.0 and ::0) with explicit binding
* as part of the path to default gateway support. Under the hood it uses
* different queries on different OSes to enumerate devices, and also exposes
* device enumeration and endpoint IP data for use elsewhere.
*
* On OSes that do not support local port enumeration or where this is not
* meaningful, this degrades to binding to wildcard.
*/
class Binder : NonCopyable
{
private:
struct _Binding
{
_Binding() :
udpSock((PhySocket *)0),
tcpListenSock((PhySocket *)0),
address() {}
PhySocket *udpSock;
PhySocket *tcpListenSock;
InetAddress address;
};
public:
Binder() {}
/**
* Close all bound ports
*
* This should be called on shutdown. It closes listen sockets and UDP ports
* but not TCP connections from any TCP listen sockets.
*
* @param phy Physical interface
*/
template<typename PHY_HANDLER_TYPE>
void closeAll(Phy<PHY_HANDLER_TYPE> &phy)
{
Mutex::Lock _l(_lock);
for(typename std::vector<_Binding>::const_iterator i(_bindings.begin());i!=_bindings.end();++i) {
phy.close(i->udpSock,false);
phy.close(i->tcpListenSock,false);
}
}
/**
* Scan local devices and addresses and rebind TCP and UDP
*
* This should be called after wake from sleep, on detected network device
* changes, on startup, or periodically (e.g. every 30-60s).
*
* @param phy Physical interface
* @param port Port to bind to on all interfaces (TCP and UDP)
* @param ignoreInterfacesByName Ignore these interfaces by name
* @param ignoreInterfacesByNamePrefix Ignore these interfaces by name-prefix (starts-with, e.g. zt ignores zt*)
* @param ignoreInterfacesByAddress Ignore these interfaces by address
* @tparam PHY_HANDLER_TYPE Type for Phy<> template
* @tparam INTERFACE_CHECKER Type for class containing shouldBindInterface() method
*/
template<typename PHY_HANDLER_TYPE,typename INTERFACE_CHECKER>
void refresh(Phy<PHY_HANDLER_TYPE> &phy,unsigned int port,INTERFACE_CHECKER &ifChecker)
{
std::map<InetAddress,std::string> localIfAddrs;
PhySocket *udps;
//PhySocket *tcps;
Mutex::Lock _l(_lock);
#ifdef __WINDOWS__
char aabuf[32768];
ULONG aalen = sizeof(aabuf);
if (GetAdaptersAddresses(AF_UNSPEC,GAA_FLAG_SKIP_ANYCAST|GAA_FLAG_SKIP_MULTICAST|GAA_FLAG_SKIP_DNS_SERVER,(void *)0,reinterpret_cast<PIP_ADAPTER_ADDRESSES>(aabuf),&aalen) == NO_ERROR) {
PIP_ADAPTER_ADDRESSES a = reinterpret_cast<PIP_ADAPTER_ADDRESSES>(aabuf);
while (a) {
PIP_ADAPTER_UNICAST_ADDRESS ua = a->FirstUnicastAddress;
while (ua) {
InetAddress ip(ua->Address.lpSockaddr);
if (ifChecker.shouldBindInterface("",ip)) {
switch(ip.ipScope()) {
default: break;
case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
case InetAddress::IP_SCOPE_GLOBAL:
case InetAddress::IP_SCOPE_SHARED:
case InetAddress::IP_SCOPE_PRIVATE:
ip.setPort(port);
localIfAddrs.insert(std::pair<InetAddress,std::string>(ip,std::string()));
break;
}
}
ua = ua->Next;
}
a = a->Next;
}
}
#else // not __WINDOWS__
/* On Linux we use an alternative method if available since getifaddrs()
* gets very slow when there are lots of network namespaces. This won't
* work unless /proc/PID/net/if_inet6 exists and it may not on some
* embedded systems, so revert to getifaddrs() there. */
#ifdef __LINUX__
char fn[256],tmp[256];
std::set<std::string> ifnames;
const unsigned long pid = (unsigned long)getpid();
// Get all device names
Utils::snprintf(fn,sizeof(fn),"/proc/%lu/net/dev",pid);
FILE *procf = fopen(fn,"r");
if (procf) {
while (fgets(tmp,sizeof(tmp),procf)) {
tmp[255] = 0;
char *saveptr = (char *)0;
for(char *f=Utils::stok(tmp," \t\r\n:|",&saveptr);(f);f=Utils::stok((char *)0," \t\r\n:|",&saveptr)) {
if ((strcmp(f,"Inter-") != 0)&&(strcmp(f,"face") != 0)&&(f[0] != 0))
ifnames.insert(f);
break; // we only want the first field
}
}
fclose(procf);
}
// Get IPv6 addresses (and any device names we don't already know)
Utils::snprintf(fn,sizeof(fn),"/proc/%lu/net/if_inet6",pid);
procf = fopen(fn,"r");
if (procf) {
while (fgets(tmp,sizeof(tmp),procf)) {
tmp[255] = 0;
char *saveptr = (char *)0;
unsigned char ipbits[16];
memset(ipbits,0,sizeof(ipbits));
char *devname = (char *)0;
int n = 0;
for(char *f=Utils::stok(tmp," \t\r\n",&saveptr);(f);f=Utils::stok((char *)0," \t\r\n",&saveptr)) {
switch(n++) {
case 0: // IP in hex
Utils::unhex(f,32,ipbits,16);
break;
case 5: // device name
devname = f;
break;
}
}
if (devname) {
ifnames.insert(devname);
InetAddress ip(ipbits,16,0);
if (ifChecker.shouldBindInterface(devname,ip)) {
switch(ip.ipScope()) {
default: break;
case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
case InetAddress::IP_SCOPE_GLOBAL:
case InetAddress::IP_SCOPE_SHARED:
case InetAddress::IP_SCOPE_PRIVATE:
ip.setPort(port);
localIfAddrs.insert(std::pair<InetAddress,std::string>(ip,std::string(devname)));
break;
}
}
}
}
fclose(procf);
}
// Get IPv4 addresses for each device
if (ifnames.size() > 0) {
const int controlfd = (int)socket(AF_INET,SOCK_DGRAM,0);
struct ifconf configuration;
configuration.ifc_len = 0;
configuration.ifc_buf = nullptr;
if (controlfd < 0) goto ip4_address_error;
if (ioctl(controlfd, SIOCGIFCONF, &configuration) < 0) goto ip4_address_error;
configuration.ifc_buf = (char*)malloc(configuration.ifc_len);
if (ioctl(controlfd, SIOCGIFCONF, &configuration) < 0) goto ip4_address_error;
for (int i=0; i < (int)(configuration.ifc_len / sizeof(ifreq)); i ++) {
struct ifreq& request = configuration.ifc_req[i];
struct sockaddr* addr = &request.ifr_ifru.ifru_addr;
if (addr->sa_family != AF_INET) continue;
std::string ifname = request.ifr_ifrn.ifrn_name;
// name can either be just interface name or interface name followed by ':' and arbitrary label
if (ifname.find(':') != std::string::npos) {
ifname = ifname.substr(0, ifname.find(':'));
}
InetAddress ip(&(((struct sockaddr_in *)addr)->sin_addr),4,0);
if (ifChecker.shouldBindInterface(ifname.c_str(), ip)) {
switch(ip.ipScope()) {
default: break;
case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
case InetAddress::IP_SCOPE_GLOBAL:
case InetAddress::IP_SCOPE_SHARED:
case InetAddress::IP_SCOPE_PRIVATE:
ip.setPort(port);
localIfAddrs.insert(std::pair<InetAddress,std::string>(ip, ifname));
break;
}
}
}
ip4_address_error:
free(configuration.ifc_buf);
if (controlfd > 0) close(controlfd);
}
const bool gotViaProc = (localIfAddrs.size() > 0);
#else
const bool gotViaProc = false;
#endif
if (!gotViaProc) {
struct ifaddrs *ifatbl = (struct ifaddrs *)0;
struct ifaddrs *ifa;
if ((getifaddrs(&ifatbl) == 0)&&(ifatbl)) {
ifa = ifatbl;
while (ifa) {
if ((ifa->ifa_name)&&(ifa->ifa_addr)) {
InetAddress ip = *(ifa->ifa_addr);
if (ifChecker.shouldBindInterface(ifa->ifa_name,ip)) {
switch(ip.ipScope()) {
default: break;
case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
case InetAddress::IP_SCOPE_GLOBAL:
case InetAddress::IP_SCOPE_SHARED:
case InetAddress::IP_SCOPE_PRIVATE:
ip.setPort(port);
localIfAddrs.insert(std::pair<InetAddress,std::string>(ip,std::string(ifa->ifa_name)));
break;
}
}
}
ifa = ifa->ifa_next;
}
freeifaddrs(ifatbl);
}
}
#endif
// Default to binding to wildcard if we can't enumerate addresses
if (localIfAddrs.empty()) {
localIfAddrs.insert(std::pair<InetAddress,std::string>(InetAddress((uint32_t)0,port),std::string()));
localIfAddrs.insert(std::pair<InetAddress,std::string>(InetAddress((const void *)"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",16,port),std::string()));
}
// Close any old bindings to anything that doesn't exist anymore
for(typename std::vector<_Binding>::const_iterator bi(_bindings.begin());bi!=_bindings.end();++bi) {
if (localIfAddrs.find(bi->address) == localIfAddrs.end()) {
phy.close(bi->udpSock,false);
phy.close(bi->tcpListenSock,false);
}
}
std::vector<_Binding> newBindings;
for(std::map<InetAddress,std::string>::const_iterator ii(localIfAddrs.begin());ii!=localIfAddrs.end();++ii) {
typename std::vector<_Binding>::const_iterator bi(_bindings.begin());
while (bi != _bindings.end()) {
if (bi->address == ii->first) {
newBindings.push_back(*bi);
break;
}
++bi;
}
if (bi == _bindings.end()) {
udps = phy.udpBind(reinterpret_cast<const struct sockaddr *>(&(ii->first)),(void *)0,ZT_UDP_DESIRED_BUF_SIZE);
if (udps) {
//tcps = phy.tcpListen(reinterpret_cast<const struct sockaddr *>(&ii),(void *)0);
//if (tcps) {
#ifdef __LINUX__
// Bind Linux sockets to their device so routes tha we manage do not override physical routes (wish all platforms had this!)
if (ii->second.length() > 0) {
int fd = (int)Phy<PHY_HANDLER_TYPE>::getDescriptor(udps);
char tmp[256];
Utils::scopy(tmp,sizeof(tmp),ii->second.c_str());
if (fd >= 0) {
if (setsockopt(fd,SOL_SOCKET,SO_BINDTODEVICE,tmp,strlen(tmp)) != 0) {
fprintf(stderr,"WARNING: unable to set SO_BINDTODEVICE to bind %s to %s\n",ii->first.toIpString().c_str(),ii->second.c_str());
}
}
}
#endif // __LINUX__
newBindings.push_back(_Binding());
newBindings.back().udpSock = udps;
//newBindings.back().tcpListenSock = tcps;
newBindings.back().address = ii->first;
//} else {
// phy.close(udps,false);
//}
}
}
}
// Swapping pointers and then letting the old one fall out of scope is faster than copying again
_bindings.swap(newBindings);
}
/**
* Send a UDP packet from the specified local interface, or all
*
* Unfortunately even by examining the routing table there is no ultimately
* robust way to tell where we might reach another host that works in all
* environments. As a result, we send packets with null (wildcard) local
* addresses from *every* bound interface.
*
* These are typically initial HELLOs, path probes, etc., since normal
* conversations will have a local endpoint address. So the cost is low and
* if the peer is not reachable via that route then the packet will go
* nowhere and nothing will happen.
*
* It will of course only send via interface bindings of the same socket
* family. No point in sending V4 via V6 or vice versa.
*
* In any case on most hosts there's only one or two interfaces that we
* will use, so none of this is particularly costly.
*
* @param local Local interface address or null address for 'all'
* @param remote Remote address
* @param data Data to send
* @param len Length of data
* @param v4ttl If non-zero, send this packet with the specified IP TTL (IPv4 only)
*/
template<typename PHY_HANDLER_TYPE>
inline bool udpSend(Phy<PHY_HANDLER_TYPE> &phy,const InetAddress &local,const InetAddress &remote,const void *data,unsigned int len,unsigned int v4ttl = 0) const
{
Mutex::Lock _l(_lock);
if (local) {
for(typename std::vector<_Binding>::const_iterator i(_bindings.begin());i!=_bindings.end();++i) {
if (i->address == local) {
if ((v4ttl)&&(local.ss_family == AF_INET))
phy.setIp4UdpTtl(i->udpSock,v4ttl);
const bool result = phy.udpSend(i->udpSock,reinterpret_cast<const struct sockaddr *>(&remote),data,len);
if ((v4ttl)&&(local.ss_family == AF_INET))
phy.setIp4UdpTtl(i->udpSock,255);
return result;
}
}
return false;
} else {
bool result = false;
for(typename std::vector<_Binding>::const_iterator i(_bindings.begin());i!=_bindings.end();++i) {
if (i->address.ss_family == remote.ss_family) {
if ((v4ttl)&&(remote.ss_family == AF_INET))
phy.setIp4UdpTtl(i->udpSock,v4ttl);
result |= phy.udpSend(i->udpSock,reinterpret_cast<const struct sockaddr *>(&remote),data,len);
if ((v4ttl)&&(remote.ss_family == AF_INET))
phy.setIp4UdpTtl(i->udpSock,255);
}
}
return result;
}
}
/**
* @return All currently bound local interface addresses
*/
inline std::vector<InetAddress> allBoundLocalInterfaceAddresses()
{
Mutex::Lock _l(_lock);
std::vector<InetAddress> aa;
for(std::vector<_Binding>::const_iterator i(_bindings.begin());i!=_bindings.end();++i)
aa.push_back(i->address);
return aa;
}
private:
std::vector<_Binding> _bindings;
Mutex _lock;
};
} // namespace ZeroTier
#endif