Beginning of local binding manager for default gateway support.

osdep/Binder.hpp

@@ -0,0 +1,223 @@
+/*
+ * 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>
+#endif
+
+#include <string>
+#include <vector>
+#include <algorithm>
+#include <utility>
+
+#include "../node/InetAddress.hpp"
+#include "../node/Mutex.hpp"
+
+#include "Phy.hpp"
+
+namespace ZeroTier {
+
+/**
+ * Enumerates local devices and binds ports 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.
+ */
+template<typename PHY_HANDLER_TYPE>
+class Binder
+{
+private:
+	struct _Binding
+	{
+		PhySocket *udpSock;
+		PhySocket *tcpListenSock;
+		InetAddress address;
+	};
+
+public:
+	/**
+	 * @param phy Physical interface to use -- be sure not to delete phy before binder
+	 * @param port Port to bind to on all interfaces (TCP and UDP)
+	 */
+	Binder(typename Phy<PHY_HANDLER_TYPE> &phy,unsigned int port) :
+		_phy(phy),
+		_port(port)
+	{
+	}
+
+	/**
+	 * Closes all bound ports -- but NOT accepted connections on those ports
+	 */
+	~Binder()
+	{
+	}
+
+	/**
+	 * 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 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
+	 */
+	void refresh(const std::vector<std::string> &ignoreInterfacesByName,const std::vector<std::string> &ignoreInterfacesByNamePrefix,const std::vector<InetAddress> &ignoreInterfacesByAddress)
+	{
+		std::vector<InetAddress> localIfAddrs;
+		std::vector<_Binding> newBindings;
+		const char *na,*nb;
+		std::vector<std::string>::const_iterator si;
+		std::vector<InetAddress>::const_iterator ii;
+		std::vector<_Binding>::const_iterator bi;
+		PhySocket *udps,*tcps;
+		InetAddress ip;
+		Mutex::Lock _l(_lock);
+
+#ifdef __WINDOWS__
+
+#else // not __WINDOWS__
+
+		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)) {
+					for(si=ignoreInterfacesByName.begin();si!=ignoreInterfacesByName.end();++si) {
+						if (*si == ifa->ifa_name)
+							goto binder_hpp_ignore_interface;
+					}
+
+					for(si=ignoreInterfacesByNamePrefix.begin();si!=ignoreInterfacesByNamePrefix.end();++si) {
+						na = si->c_str();
+						nb = ifa->ifa_name;
+						while (*nb) {
+							if (*(na++) != *(nb++))
+								goto binder_hpp_interface_prefixes_dont_match;
+						}
+						goto binder_hpp_ignore_interface;
+					}
+
+binder_hpp_interface_prefixes_dont_match:
+					ip = *(ifa->ifa_addr);
+					switch(ip.ipScope()) {
+						default: break;
+						case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
+						case InetAddress::IP_SCOPE_GLOBAL:
+						case InetAddress::IP_SCOPE_LINK_LOCAL:
+						case InetAddress::IP_SCOPE_SHARED:
+						case InetAddress::IP_SCOPE_PRIVATE:
+							for(ii=ignoreInterfacesByAddress.begin();ii!=ignoreInterfacesByAddress.end();++ii) {
+								if (ip.ipsEqual(*ii))
+									goto binder_hpp_ignore_interface;
+							}
+
+							ip.setPort(_port);
+							localIfAddrs.push(ip);
+
+							break;
+					}
+				}
+
+binder_hpp_ignore_interface:
+				ifa = ifa->ifa_next;
+			}
+		}
+
+		freeifaddrs(ifatbl);
+
+#endif
+
+		if (localIfAddrs.size() == 0) {
+			localIfAddrs.push_back(InetAddress((uint32_t)0,_port));
+			localIfAddrs.push_back(InetAddress((const void *)"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",16,_port));
+		} else {
+			std::sort(localIfAddrs.begin(),localIfAddrs.end());
+		}
+
+		for(bi=_bindings.begin();bi!=_bindings.end();++bi) {
+			if (std::find(localIfAddrs.begin(),localIfAddrs.end(),bi->address) == localIfAddrs.end()) {
+				_phy.close(bi->udpSock,false);
+				_phy.close(bi->tcpListenSock,false);
+			}
+		}
+
+		for(ii=localIfAddrs.begin();ii!=localIfAddrs.end();++ii) {
+			for(bi=_bindings.begin();bi!=_bindings.end();++bi) {
+				if (bi->address == *ii) {
+					newBindings.push_back(*bi);
+					break;
+				}
+			}
+
+			if (bi == _bindings.end()) {
+				udps = _phy.udpBind(reinterpret_cast<const struct sockaddr *>(&ii),(void *)0,131072);
+				if (udps) {
+					tcps = _phy.tcpListen(reinterpret_cast<const struct sockaddr *>(&ii),(void *)0);
+					if (tcps) {
+						newBindings.push_back(_Binding());
+						newBindings.back().udpSock = udps;
+						newBindings.back().tcpListenSock = tcps;
+						newBindings.back().address = *ii;
+					} else {
+						_phy.close(udps,false);
+					}
+				}
+			}
+		}
+
+		_bindings.swap(newBindings);
+	}
+
+private:
+	std::vector<_Binding> _bindings;
+	typename Phy<PHY_HANDLER_TYPE> &_phy;
+	unsigned int _port;
+	Mutex _lock;
+};
+
+} // namespace ZeroTier
+
+#endif