ZeroTierOne/node/Network.cpp

/*
 * 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

#include "Constants.hpp"
#include "../version.h"
#include "Network.hpp"
#include "RuntimeEnvironment.hpp"
#include "MAC.hpp"
#include "Address.hpp"
#include "InetAddress.hpp"
#include "Switch.hpp"
#include "Buffer.hpp"
#include "Packet.hpp"
#include "NetworkController.hpp"
#include "Node.hpp"
#include "Peer.hpp"

// Uncomment to enable ZT_NETWORK_RULE_ACTION_DEBUG_LOG rule output to STDOUT
#define ZT_RULES_ENGINE_DEBUGGING 1

namespace ZeroTier {

#ifdef ZT_RULES_ENGINE_DEBUGGING
#define FILTER_TRACE(f,...) { Utils::snprintf(dpbuf,sizeof(dpbuf),f,##__VA_ARGS__); dlog.push_back(std::string(dpbuf)); }
static const char *_rtn(const ZT_VirtualNetworkRuleType rt)
{
	switch(rt) {
		case ZT_NETWORK_RULE_ACTION_DROP: return "ACTION_DROP";
		case ZT_NETWORK_RULE_ACTION_ACCEPT: return "ACTION_ACCEPT";
		case ZT_NETWORK_RULE_ACTION_TEE: return "ACTION_TEE";
		case ZT_NETWORK_RULE_ACTION_REDIRECT: return "ACTION_REDIRECT";
		case ZT_NETWORK_RULE_ACTION_DEBUG_LOG: return "ACTION_DEBUG_LOG";
		case ZT_NETWORK_RULE_MATCH_SOURCE_ZEROTIER_ADDRESS: return "MATCH_SOURCE_ZEROTIER_ADDRESS";
		case ZT_NETWORK_RULE_MATCH_DEST_ZEROTIER_ADDRESS: return "MATCH_DEST_ZEROTIER_ADDRESS";
		case ZT_NETWORK_RULE_MATCH_VLAN_ID: return "MATCH_VLAN_ID";
		case ZT_NETWORK_RULE_MATCH_VLAN_PCP: return "MATCH_VLAN_PCP";
		case ZT_NETWORK_RULE_MATCH_VLAN_DEI: return "MATCH_VLAN_DEI";
		case ZT_NETWORK_RULE_MATCH_ETHERTYPE: return "MATCH_ETHERTYPE";
		case ZT_NETWORK_RULE_MATCH_MAC_SOURCE: return "MATCH_MAC_SOURCE";
		case ZT_NETWORK_RULE_MATCH_MAC_DEST: return "MATCH_MAC_DEST";
		case ZT_NETWORK_RULE_MATCH_IPV4_SOURCE: return "MATCH_IPV4_SOURCE";
		case ZT_NETWORK_RULE_MATCH_IPV4_DEST: return "MATCH_IPV4_DEST";
		case ZT_NETWORK_RULE_MATCH_IPV6_SOURCE: return "MATCH_IPV6_SOURCE";
		case ZT_NETWORK_RULE_MATCH_IPV6_DEST: return "MATCH_IPV6_DEST";
		case ZT_NETWORK_RULE_MATCH_IP_TOS: return "MATCH_IP_TOS";
		case ZT_NETWORK_RULE_MATCH_IP_PROTOCOL: return "MATCH_IP_PROTOCOL";
		case ZT_NETWORK_RULE_MATCH_IP_SOURCE_PORT_RANGE: return "MATCH_IP_SOURCE_PORT_RANGE";
		case ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE: return "MATCH_IP_DEST_PORT_RANGE";
		case ZT_NETWORK_RULE_MATCH_CHARACTERISTICS: return "MATCH_CHARACTERISTICS";
		case ZT_NETWORK_RULE_MATCH_FRAME_SIZE_RANGE: return "MATCH_FRAME_SIZE_RANGE";
		case ZT_NETWORK_RULE_MATCH_TAGS_SAMENESS: return "MATCH_TAGS_SAMENESS";
		case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_AND: return "MATCH_TAGS_BITWISE_AND";
		case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_OR: return "MATCH_TAGS_BITWISE_OR";
		case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_XOR: return "MATCH_TAGS_BITWISE_XOR";
		default: return "BAD_RULE_TYPE";
	}
}
#else
#define FILTER_TRACE(f,...) {}
#endif // ZT_RULES_ENGINE_DEBUGGING

// Returns true if packet appears valid; pos and proto will be set
static bool _ipv6GetPayload(const uint8_t *frameData,unsigned int frameLen,unsigned int &pos,unsigned int &proto)
{
	if (frameLen < 40)
		return false;
	pos = 40;
	proto = frameData[6];
	while (pos <= frameLen) {
		switch(proto) {
			case 0: // hop-by-hop options
			case 43: // routing
			case 60: // destination options
			case 135: // mobility options
				if ((pos + 8) > frameLen)
					return false; // invalid!
				proto = frameData[pos];
				pos += ((unsigned int)frameData[pos + 1] * 8) + 8;
				break;

			//case 44: // fragment -- we currently can't parse these and they are deprecated in IPv6 anyway
			//case 50:
			//case 51: // IPSec ESP and AH -- we have to stop here since this is encrypted stuff
			default:
				return true;
		}
	}
	return false; // overflow == invalid
}

// 0 == no match, -1 == match/drop, 1 == match/accept
static int _doZtFilter(
	const RuntimeEnvironment *RR,
	const bool noRedirect,
	const NetworkConfig &nconf,
	const bool inbound,
	const Address &ztSource,
	const Address &ztDest,
	const MAC &macSource,
	const MAC &macDest,
	const uint8_t *const frameData,
	const unsigned int frameLen,
	const unsigned int etherType,
	const unsigned int vlanId,
	const ZT_VirtualNetworkRule *rules,
	const unsigned int ruleCount,
	const Tag *localTags,
	const unsigned int localTagCount,
	const uint32_t *const remoteTagIds,
	const uint32_t *const remoteTagValues,
	const unsigned int remoteTagCount)
{
	// For each set of rules we start by assuming that they match (since no constraints
	// yields a 'match all' rule).
	uint8_t thisSetMatches = 1;

#ifdef ZT_RULES_ENGINE_DEBUGGING
	std::vector<std::string> dlog;
	char dpbuf[1024];
#endif // ZT_RULES_ENGINE_DEBUGGING

	for(unsigned int rn=0;rn<ruleCount;++rn) {
		const ZT_VirtualNetworkRuleType rt = (ZT_VirtualNetworkRuleType)(rules[rn].t & 0x7f);

		switch(rt) {
			case ZT_NETWORK_RULE_ACTION_DROP:
				if (thisSetMatches) {
					return -1; // match, drop packet
				} else {
#ifdef ZT_RULES_ENGINE_DEBUGGING
					dlog.clear();
#endif // ZT_RULES_ENGINE_DEBUGGING
					thisSetMatches = 1; // no match, evaluate next set
				}
				continue;
			case ZT_NETWORK_RULE_ACTION_ACCEPT:
				if (thisSetMatches) {
					return 1; // match, accept packet
				} else {
#ifdef ZT_RULES_ENGINE_DEBUGGING
					dlog.clear();
#endif // ZT_RULES_ENGINE_DEBUGGING
					thisSetMatches = 1; // no match, evaluate next set
				}
				continue;
			case ZT_NETWORK_RULE_ACTION_TEE:
			case ZT_NETWORK_RULE_ACTION_REDIRECT: {
				const Address fwdAddr(rules[rn].v.fwd.address);
				if (fwdAddr == RR->identity.address()) {
					// If we are the TEE or REDIRECT destination, don't TEE or REDIRECT
					// to self. We should also accept here instead of interpreting
					// REDIRECT as DROP since we are the destination.
#ifdef ZT_RULES_ENGINE_DEBUGGING
					dlog.clear();
#endif // ZT_RULES_ENGINE_DEBUGGING
					thisSetMatches = 1;
				} else {
					if (!noRedirect) {
						Packet outp(fwdAddr,RR->identity.address(),Packet::VERB_EXT_FRAME);
						outp.append(nconf.networkId);
						outp.append((uint8_t)( ((rt == ZT_NETWORK_RULE_ACTION_REDIRECT) ? 0x04 : 0x02) | (inbound ? 0x08 : 0x00) ));
						macDest.appendTo(outp);
						macSource.appendTo(outp);
						outp.append((uint16_t)etherType);
						outp.append(frameData,(rules[rn].v.fwd.length != 0) ? ((frameLen < (unsigned int)rules[rn].v.fwd.length) ? frameLen : (unsigned int)rules[rn].v.fwd.length) : frameLen);
						outp.compress();
						RR->sw->send(outp,true);
					}

					if (rt == ZT_NETWORK_RULE_ACTION_REDIRECT) {
						return -1; // match, drop packet (we redirected it)
					} else {
#ifdef ZT_RULES_ENGINE_DEBUGGING
						dlog.clear();
#endif // ZT_RULES_ENGINE_DEBUGGING
						thisSetMatches = 1; // TEE does not terminate evaluation
					}
				}
			}	continue;
			case ZT_NETWORK_RULE_ACTION_DEBUG_LOG:
#ifdef ZT_RULES_ENGINE_DEBUGGING
				printf(" _ " ZT_EOL_S);
				for(std::vector<std::string>::iterator m(dlog.begin());m!=dlog.end();++m)
					printf(" | %s" ZT_EOL_S,m->c_str());
				printf(" + %c %s->%s %.2x:%.2x:%.2x:%.2x:%.2x:%.2x->%.2x:%.2x:%.2x:%.2x:%.2x:%.2x inbound=%d noRedirect=%d frameLen=%u etherType=%u" ZT_EOL_S,
					((thisSetMatches) ? 'Y' : 'n'),
					ztSource.toString().c_str(),
					ztDest.toString().c_str(),
					(unsigned int)macSource[0],
					(unsigned int)macSource[1],
					(unsigned int)macSource[2],
					(unsigned int)macSource[3],
					(unsigned int)macSource[4],
					(unsigned int)macSource[5],
					(unsigned int)macDest[0],
					(unsigned int)macDest[1],
					(unsigned int)macDest[2],
					(unsigned int)macDest[3],
					(unsigned int)macDest[4],
					(unsigned int)macDest[5],
					(int)inbound,
					(int)noRedirect,
					frameLen,
					etherType
				);
				dlog.clear();
#endif // ZT_RULES_ENGINE_DEBUGGING
				thisSetMatches = 1; // DEBUG_LOG does not terminate evaluation
				continue;

			default: break;
		}

		// No need to evaluate MATCH entries beyond where thisSetMatches is no longer still true
		if (!thisSetMatches)
			continue;

		uint8_t thisRuleMatches = 0;

		switch(rt) {
			case ZT_NETWORK_RULE_MATCH_SOURCE_ZEROTIER_ADDRESS:
				thisRuleMatches = (uint8_t)(rules[rn].v.zt == ztSource.toInt());
				FILTER_TRACE("%u %s %c %.10llx==%.10llx -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),rules[rn].v.zt,ztSource.toInt(),(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_DEST_ZEROTIER_ADDRESS:
				thisRuleMatches = (uint8_t)(rules[rn].v.zt == ztDest.toInt());
				FILTER_TRACE("%u %s %c %.10llx==%.10llx -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),rules[rn].v.zt,ztDest.toInt(),(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_VLAN_ID:
				thisRuleMatches = (uint8_t)(rules[rn].v.vlanId == (uint16_t)vlanId);
				FILTER_TRACE("%u %s %c %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.vlanId,(unsigned int)vlanId,(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_VLAN_PCP:
				// NOT SUPPORTED YET
				thisRuleMatches = (uint8_t)(rules[rn].v.vlanPcp == 0);
				FILTER_TRACE("%u %s %c %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.vlanPcp,0,(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_VLAN_DEI:
				// NOT SUPPORTED YET
				thisRuleMatches = (uint8_t)(rules[rn].v.vlanDei == 0);
				FILTER_TRACE("%u %s %c %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.vlanDei,0,(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_ETHERTYPE:
				thisRuleMatches = (uint8_t)(rules[rn].v.etherType == (uint16_t)etherType);
				FILTER_TRACE("%u %s %c %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.etherType,etherType,(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_MAC_SOURCE:
				thisRuleMatches = (uint8_t)(MAC(rules[rn].v.mac,6) == macSource);
				FILTER_TRACE("%u %s %c %.12llx=%.12llx -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),rules[rn].v.mac,macSource.toInt(),(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_MAC_DEST:
				thisRuleMatches = (uint8_t)(MAC(rules[rn].v.mac,6) == macDest);
				FILTER_TRACE("%u %s %c %.12llx=%.12llx -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),rules[rn].v.mac,macDest.toInt(),(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_IPV4_SOURCE:
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
					thisRuleMatches = (uint8_t)(InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).containsAddress(InetAddress((const void *)(frameData + 12),4,0)));
					FILTER_TRACE("%u %s %c %s contains %s -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).toString().c_str(),InetAddress((const void *)(frameData + 12),4,0).toIpString().c_str(),(unsigned int)thisRuleMatches);
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IPv4] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IPV4_DEST:
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
					thisRuleMatches = (uint8_t)(InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).containsAddress(InetAddress((const void *)(frameData + 16),4,0)));
					FILTER_TRACE("%u %s %c %s contains %s -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).toString().c_str(),InetAddress((const void *)(frameData + 16),4,0).toIpString().c_str(),(unsigned int)thisRuleMatches);
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IPv4] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IPV6_SOURCE:
				if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
					thisRuleMatches = (uint8_t)(InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).containsAddress(InetAddress((const void *)(frameData + 8),16,0)));
					FILTER_TRACE("%u %s %c %s contains %s -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).toString().c_str(),InetAddress((const void *)(frameData + 8),16,0).toIpString().c_str(),(unsigned int)thisRuleMatches);
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IPv6] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IPV6_DEST:
				if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
					thisRuleMatches = (uint8_t)(InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).containsAddress(InetAddress((const void *)(frameData + 24),16,0)));
					FILTER_TRACE("%u %s %c %s contains %s -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).toString().c_str(),InetAddress((const void *)(frameData + 24),16,0).toIpString().c_str(),(unsigned int)thisRuleMatches);
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IPv6] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IP_TOS:
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
					thisRuleMatches = (uint8_t)(rules[rn].v.ipTos == ((frameData[1] & 0xfc) >> 2));
					FILTER_TRACE("%u %s %c (IPv4) %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.ipTos,(unsigned int)((frameData[1] & 0xfc) >> 2),(unsigned int)thisRuleMatches);
				} else if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
					const uint8_t trafficClass = ((frameData[0] << 4) & 0xf0) | ((frameData[1] >> 4) & 0x0f);
					thisRuleMatches = (uint8_t)(rules[rn].v.ipTos == ((trafficClass & 0xfc) >> 2));
					FILTER_TRACE("%u %s %c (IPv6) %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.ipTos,(unsigned int)((trafficClass & 0xfc) >> 2),(unsigned int)thisRuleMatches);
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IP] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IP_PROTOCOL:
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
					thisRuleMatches = (uint8_t)(rules[rn].v.ipProtocol == frameData[9]);
					FILTER_TRACE("%u %s %c (IPv4) %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.ipProtocol,(unsigned int)frameData[9],(unsigned int)thisRuleMatches);
				} else if (etherType == ZT_ETHERTYPE_IPV6) {
					unsigned int pos = 0,proto = 0;
					if (_ipv6GetPayload(frameData,frameLen,pos,proto)) {
						thisRuleMatches = (uint8_t)(rules[rn].v.ipProtocol == (uint8_t)proto);
						FILTER_TRACE("%u %s %c (IPv6) %u==%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.ipProtocol,proto,(unsigned int)thisRuleMatches);
					} else {
						thisRuleMatches = 0;
						FILTER_TRACE("%u %s %c [invalid IPv6] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
					}
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IP] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_IP_SOURCE_PORT_RANGE:
			case ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE:
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
					const unsigned int headerLen = 4 * (frameData[0] & 0xf);
					int p = -1;
					switch(frameData[9]) { // IP protocol number
						// All these start with 16-bit source and destination port in that order
						case 0x06: // TCP
						case 0x11: // UDP
						case 0x84: // SCTP
						case 0x88: // UDPLite
							if (frameLen > (headerLen + 4)) {
								unsigned int pos = headerLen + ((rt == ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE) ? 2 : 0);
								p = (int)frameData[pos++] << 8;
								p |= (int)frameData[pos];
							}
							break;
					}

					thisRuleMatches = (p >= 0) ? (uint8_t)((p >= (int)rules[rn].v.port[0])&&(p <= (int)rules[rn].v.port[1])) : (uint8_t)0;
					FILTER_TRACE("%u %s %c (IPv4) %d in %d-%d -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),p,(int)rules[rn].v.port[0],(int)rules[rn].v.port[1],(unsigned int)thisRuleMatches);
				} else if (etherType == ZT_ETHERTYPE_IPV6) {
					unsigned int pos = 0,proto = 0;
					if (_ipv6GetPayload(frameData,frameLen,pos,proto)) {
						int p = -1;
						switch(proto) { // IP protocol number
							// All these start with 16-bit source and destination port in that order
							case 0x06: // TCP
							case 0x11: // UDP
							case 0x84: // SCTP
							case 0x88: // UDPLite
								if (frameLen > (pos + 4)) {
									if (rt == ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE) pos += 2;
									p = (int)frameData[pos++] << 8;
									p |= (int)frameData[pos];
								}
								break;
						}
						thisRuleMatches = (p > 0) ? (uint8_t)((p >= (int)rules[rn].v.port[0])&&(p <= (int)rules[rn].v.port[1])) : (uint8_t)0;
						FILTER_TRACE("%u %s %c (IPv6) %d in %d-%d -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),p,(int)rules[rn].v.port[0],(int)rules[rn].v.port[1],(unsigned int)thisRuleMatches);
					} else {
						thisRuleMatches = 0;
						FILTER_TRACE("%u %s %c [invalid IPv6] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
					}
				} else {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c [frame not IP] -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='));
				}
				break;
			case ZT_NETWORK_RULE_MATCH_CHARACTERISTICS: {
				uint64_t cf = (inbound) ? ZT_RULE_PACKET_CHARACTERISTICS_INBOUND : 0ULL;
				if (macDest.isMulticast()) cf |= ZT_RULE_PACKET_CHARACTERISTICS_MULTICAST;
				if (macDest.isBroadcast()) cf |= ZT_RULE_PACKET_CHARACTERISTICS_BROADCAST;
				if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)&&(frameData[9] == 0x06)) {
					const unsigned int headerLen = 4 * (frameData[0] & 0xf);
					cf |= (uint64_t)frameData[headerLen + 13];
					cf |= (((uint64_t)(frameData[headerLen + 12] & 0x0f)) << 8);
				} else if (etherType == ZT_ETHERTYPE_IPV6) {
					unsigned int pos = 0,proto = 0;
					if (_ipv6GetPayload(frameData,frameLen,pos,proto)) {
						if ((proto == 0x06)&&(frameLen > (pos + 14))) {
							cf |= (uint64_t)frameData[pos + 13];
							cf |= (((uint64_t)(frameData[pos + 12] & 0x0f)) << 8);
						}
					}
				}
				thisRuleMatches = (uint8_t)((cf & rules[rn].v.characteristics[0]) == rules[rn].v.characteristics[1]);
				FILTER_TRACE("%u %s %c (%.16llx & %.16llx)==%.16llx -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),cf,rules[rn].v.characteristics[0],rules[rn].v.characteristics[1],(unsigned int)thisRuleMatches);
			}	break;
			case ZT_NETWORK_RULE_MATCH_FRAME_SIZE_RANGE:
				thisRuleMatches = (uint8_t)((frameLen >= (unsigned int)rules[rn].v.frameSize[0])&&(frameLen <= (unsigned int)rules[rn].v.frameSize[1]));
				FILTER_TRACE("%u %s %c %u in %u-%u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),frameLen,(unsigned int)rules[rn].v.frameSize[0],(unsigned int)rules[rn].v.frameSize[1],(unsigned int)thisRuleMatches);
				break;
			case ZT_NETWORK_RULE_MATCH_TAGS_SAMENESS:
			case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_AND:
			case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_OR:
			case ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_XOR: {
				const Tag *lt = (const Tag *)0;
				for(unsigned int i=0;i<localTagCount;++i) {
					if (rules[rn].v.tag.id == localTags[i].id()) {
						lt = &(localTags[i]);
						break;
					}
				}
				if (!lt) {
					thisRuleMatches = 0;
					FILTER_TRACE("%u %s %c local tag %u not found -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id);
				} else {
					const uint32_t *rtv = (const uint32_t *)0;
					for(unsigned int i=0;i<remoteTagCount;++i) {
						if (rules[rn].v.tag.id == remoteTagIds[i]) {
							rtv = &(remoteTagValues[i]);
							break;
						}
					}
					if (!rtv) {
						thisRuleMatches = 0;
						FILTER_TRACE("%u %s %c remote tag %u not found -> 0",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id);
					} else {
						if (rt == ZT_NETWORK_RULE_MATCH_TAGS_SAMENESS) {
							const uint32_t sameness = (lt->value() > *rtv) ? (lt->value() - *rtv) : (*rtv - lt->value());
							thisRuleMatches = (uint8_t)(sameness <= rules[rn].v.tag.value);
							FILTER_TRACE("%u %s %c TAG %u local:%u remote:%u sameness:%u <= %u -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id,lt->value(),*rtv,sameness,(unsigned int)rules[rn].v.tag.value,thisRuleMatches);
						} else if (rt == ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_AND) {
							thisRuleMatches = (uint8_t)((lt->value() & *rtv) == rules[rn].v.tag.value);
							FILTER_TRACE("%u %s %c TAG %u local:%.8x & remote:%.8x == %.8x -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id,lt->value(),*rtv,(unsigned int)rules[rn].v.tag.value,(unsigned int)thisRuleMatches);
						} else if (rt == ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_OR) {
							thisRuleMatches = (uint8_t)((lt->value() | *rtv) == rules[rn].v.tag.value);
							FILTER_TRACE("%u %s %c TAG %u local:%.8x | remote:%.8x == %.8x -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id,lt->value(),*rtv,(unsigned int)rules[rn].v.tag.value,(unsigned int)thisRuleMatches);
						} else if (rt == ZT_NETWORK_RULE_MATCH_TAGS_BITWISE_XOR) {
							thisRuleMatches = (uint8_t)((lt->value() ^ *rtv) == rules[rn].v.tag.value);
							FILTER_TRACE("%u %s %c TAG %u local:%.8x ^ remote:%.8x == %.8x -> %u",rn,_rtn(rt),(((rules[rn].t & 0x80) != 0) ? '!' : '='),(unsigned int)rules[rn].v.tag.id,lt->value(),*rtv,(unsigned int)rules[rn].v.tag.value,(unsigned int)thisRuleMatches);
						} else { // sanity check, can't really happen
							thisRuleMatches = 0;
						}
					}
				}
			}	break;

			default: continue;
		}

		// thisSetMatches remains true if the current rule matched (or did NOT match if NOT bit is set)
		thisSetMatches &= (thisRuleMatches ^ ((rules[rn].t >> 7) & 1));
	}

	return 0;
}

const ZeroTier::MulticastGroup Network::BROADCAST(ZeroTier::MAC(0xffffffffffffULL),0);

Network::Network(const RuntimeEnvironment *renv,uint64_t nwid,void *uptr) :
	RR(renv),
	_uPtr(uptr),
	_id(nwid),
	_mac(renv->identity.address(),nwid),
	_portInitialized(false),
	_inboundConfigPacketId(0),
	_lastConfigUpdate(0),
	_lastRequestedConfiguration(0),
	_destroyed(false),
	_netconfFailure(NETCONF_FAILURE_NONE),
	_portError(0)
{
	char confn[128];
	Utils::snprintf(confn,sizeof(confn),"networks.d/%.16llx.conf",_id);

	bool gotConf = false;
	Dictionary<ZT_NETWORKCONFIG_DICT_CAPACITY> *dconf = new Dictionary<ZT_NETWORKCONFIG_DICT_CAPACITY>();
	NetworkConfig *nconf = new NetworkConfig();
	try {
		std::string conf(RR->node->dataStoreGet(confn));
		if (conf.length()) {
			dconf->load(conf.c_str());
			if (nconf->fromDictionary(*dconf)) {
				this->setConfiguration(*nconf,false);
				_lastConfigUpdate = 0; // we still want to re-request a new config from the network
				gotConf = true;
			}
		}
	} catch ( ... ) {} // ignore invalids, we'll re-request
	delete nconf;
	delete dconf;

	if (!gotConf) {
		// Save a one-byte CR to persist membership while we request a real netconf
		RR->node->dataStorePut(confn,"\n",1,false);
	}

	if (!_portInitialized) {
		ZT_VirtualNetworkConfig ctmp;
		_externalConfig(&ctmp);
		_portError = RR->node->configureVirtualNetworkPort(_id,&_uPtr,ZT_VIRTUAL_NETWORK_CONFIG_OPERATION_UP,&ctmp);
		_portInitialized = true;
	}
}

Network::~Network()
{
	ZT_VirtualNetworkConfig ctmp;
	_externalConfig(&ctmp);

	char n[128];
	if (_destroyed) {
		RR->node->configureVirtualNetworkPort(_id,&_uPtr,ZT_VIRTUAL_NETWORK_CONFIG_OPERATION_DESTROY,&ctmp);
		Utils::snprintf(n,sizeof(n),"networks.d/%.16llx.conf",_id);
		RR->node->dataStoreDelete(n);
	} else {
		RR->node->configureVirtualNetworkPort(_id,&_uPtr,ZT_VIRTUAL_NETWORK_CONFIG_OPERATION_DOWN,&ctmp);
	}
}

bool Network::filterOutgoingPacket(
	const bool noRedirect,
	const Address &ztSource,
	const Address &ztDest,
	const MAC &macSource,
	const MAC &macDest,
	const uint8_t *frameData,
	const unsigned int frameLen,
	const unsigned int etherType,
	const unsigned int vlanId)
{
	uint32_t remoteTagIds[ZT_MAX_NETWORK_TAGS];
	uint32_t remoteTagValues[ZT_MAX_NETWORK_TAGS];

	Mutex::Lock _l(_lock);

	Membership &m = _memberships[ztDest];
	const unsigned int remoteTagCount = m.getAllTags(_config,remoteTagIds,remoteTagValues,ZT_MAX_NETWORK_TAGS);

	switch(_doZtFilter(RR,noRedirect,_config,false,ztSource,ztDest,macSource,macDest,frameData,frameLen,etherType,vlanId,_config.rules,_config.ruleCount,_config.tags,_config.tagCount,remoteTagIds,remoteTagValues,remoteTagCount)) {
		case -1:
			if (ztDest)
				m.sendCredentialsIfNeeded(RR,RR->node->now(),ztDest,_config,(const Capability *)0);
			return false;
		case 1:
			if (ztDest)
				m.sendCredentialsIfNeeded(RR,RR->node->now(),ztDest,_config,(const Capability *)0);
			return true;
	}

	for(unsigned int c=0;c<_config.capabilityCount;++c) {
		switch (_doZtFilter(RR,noRedirect,_config,false,ztSource,ztDest,macSource,macDest,frameData,frameLen,etherType,vlanId,_config.capabilities[c].rules(),_config.capabilities[c].ruleCount(),_config.tags,_config.tagCount,remoteTagIds,remoteTagValues,remoteTagCount)) {
			case -1:
				if (ztDest)
					m.sendCredentialsIfNeeded(RR,RR->node->now(),ztDest,_config,(const Capability *)0);
				return false;
			case 1:
				if (ztDest)
					m.sendCredentialsIfNeeded(RR,RR->node->now(),ztDest,_config,&(_config.capabilities[c]));
				return true;
		}
	}

	return false;
}

bool Network::filterIncomingPacket(
	const SharedPtr<Peer> &sourcePeer,
	const Address &ztDest,
	const MAC &macSource,
	const MAC &macDest,
	const uint8_t *frameData,
	const unsigned int frameLen,
	const unsigned int etherType,
	const unsigned int vlanId)
{
	uint32_t remoteTagIds[ZT_MAX_NETWORK_TAGS];
	uint32_t remoteTagValues[ZT_MAX_NETWORK_TAGS];

	Mutex::Lock _l(_lock);

	Membership &m = _memberships[ztDest];
	const unsigned int remoteTagCount = m.getAllTags(_config,remoteTagIds,remoteTagValues,ZT_MAX_NETWORK_TAGS);

	switch (_doZtFilter(RR,false,_config,true,sourcePeer->address(),ztDest,macSource,macDest,frameData,frameLen,etherType,vlanId,_config.rules,_config.ruleCount,_config.tags,_config.tagCount,remoteTagIds,remoteTagValues,remoteTagCount)) {
		case -1:
			return false;
		case 1:
			return true;
	}

	Membership::CapabilityIterator mci(m);
	const Capability *c;
	while ((c = mci.next(_config))) {
		switch(_doZtFilter(RR,false,_config,false,sourcePeer->address(),ztDest,macSource,macDest,frameData,frameLen,etherType,vlanId,c->rules(),c->ruleCount(),_config.tags,_config.tagCount,remoteTagIds,remoteTagValues,remoteTagCount)) {
			case -1:
				return false;
			case 1:
				return true;
		}
	}

	return false;
}

bool Network::subscribedToMulticastGroup(const MulticastGroup &mg,bool includeBridgedGroups) const
{
	Mutex::Lock _l(_lock);
	if (std::binary_search(_myMulticastGroups.begin(),_myMulticastGroups.end(),mg))
		return true;
	else if (includeBridgedGroups)
		return _multicastGroupsBehindMe.contains(mg);
	else return false;
}

void Network::multicastSubscribe(const MulticastGroup &mg)
{
	{
		Mutex::Lock _l(_lock);
		if (std::binary_search(_myMulticastGroups.begin(),_myMulticastGroups.end(),mg))
			return;
		_myMulticastGroups.push_back(mg);
		std::sort(_myMulticastGroups.begin(),_myMulticastGroups.end());
	}
	_announceMulticastGroups();
}

void Network::multicastUnsubscribe(const MulticastGroup &mg)
{
	Mutex::Lock _l(_lock);
	std::vector<MulticastGroup> nmg;
	for(std::vector<MulticastGroup>::const_iterator i(_myMulticastGroups.begin());i!=_myMulticastGroups.end();++i) {
		if (*i != mg)
			nmg.push_back(*i);
	}
	if (nmg.size() != _myMulticastGroups.size())
		_myMulticastGroups.swap(nmg);
}

bool Network::tryAnnounceMulticastGroupsTo(const SharedPtr<Peer> &peer)
{
	Mutex::Lock _l(_lock);
	if (
	    (_isAllowed(peer)) ||
	    (peer->address() == this->controller()) ||
	    (RR->topology->isUpstream(peer->identity()))
	   ) {
		_announceMulticastGroupsTo(peer,_allMulticastGroups());
		return true;
	}
	return false;
}

bool Network::applyConfiguration(const NetworkConfig &conf)
{
	if (_destroyed) // sanity check
		return false;
	try {
		if ((conf.networkId == _id)&&(conf.issuedTo == RR->identity.address())) {
			ZT_VirtualNetworkConfig ctmp;
			bool portInitialized;
			{
				Mutex::Lock _l(_lock);
				_config = conf;
				_lastConfigUpdate = RR->node->now();
				_netconfFailure = NETCONF_FAILURE_NONE;
				_externalConfig(&ctmp);
				portInitialized = _portInitialized;
				_portInitialized = true;
			}
			_portError = RR->node->configureVirtualNetworkPort(_id,&_uPtr,(portInitialized) ? ZT_VIRTUAL_NETWORK_CONFIG_OPERATION_CONFIG_UPDATE : ZT_VIRTUAL_NETWORK_CONFIG_OPERATION_UP,&ctmp);
			return true;
		} else {
			TRACE("ignored invalid configuration for network %.16llx (configuration contains mismatched network ID or issued-to address)",(unsigned long long)_id);
		}
	} catch (std::exception &exc) {
		TRACE("ignored invalid configuration for network %.16llx (%s)",(unsigned long long)_id,exc.what());
	} catch ( ... ) {
		TRACE("ignored invalid configuration for network %.16llx (unknown exception)",(unsigned long long)_id);
	}
	return false;
}

int Network::setConfiguration(const NetworkConfig &nconf,bool saveToDisk)
{
	try {
		{
			Mutex::Lock _l(_lock);
			if (_config == nconf)
				return 1; // OK config, but duplicate of what we already have
		}
		if (applyConfiguration(nconf)) {
			if (saveToDisk) {
				char n[64];
				Utils::snprintf(n,sizeof(n),"networks.d/%.16llx.conf",_id);
				Dictionary<ZT_NETWORKCONFIG_DICT_CAPACITY> d;
				if (nconf.toDictionary(d,false))
					RR->node->dataStorePut(n,(const void *)d.data(),d.sizeBytes(),true);
			}
			return 2; // OK and configuration has changed
		}
	} catch ( ... ) {
		TRACE("ignored invalid configuration for network %.16llx",(unsigned long long)_id);
	}
	return 0;
}

void Network::handleInboundConfigChunk(const uint64_t inRePacketId,const void *data,unsigned int chunkSize,unsigned int chunkIndex,unsigned int totalSize)
{
	std::string newConfig;
	if ((_inboundConfigPacketId == inRePacketId)&&(totalSize < ZT_NETWORKCONFIG_DICT_CAPACITY)&&((chunkIndex + chunkSize) <= totalSize)) {
		Mutex::Lock _l(_lock);

		_inboundConfigChunks[chunkIndex].append((const char *)data,chunkSize);

		unsigned int totalWeHave = 0;
		for(std::map<unsigned int,std::string>::iterator c(_inboundConfigChunks.begin());c!=_inboundConfigChunks.end();++c)
			totalWeHave += (unsigned int)c->second.length();

		if (totalWeHave == totalSize) {
			TRACE("have all chunks for network config request %.16llx, assembling...",inRePacketId);
			for(std::map<unsigned int,std::string>::iterator c(_inboundConfigChunks.begin());c!=_inboundConfigChunks.end();++c)
				newConfig.append(c->second);
			_inboundConfigPacketId = 0;
			_inboundConfigChunks.clear();
		} else if (totalWeHave > totalSize) {
			_inboundConfigPacketId = 0;
			_inboundConfigChunks.clear();
		}
	} else {
		return;
	}

	if ((newConfig.length() > 0)&&(newConfig.length() < ZT_NETWORKCONFIG_DICT_CAPACITY)) {
		Dictionary<ZT_NETWORKCONFIG_DICT_CAPACITY> *dict = new Dictionary<ZT_NETWORKCONFIG_DICT_CAPACITY>(newConfig.c_str());
		NetworkConfig *nc = new NetworkConfig();
		try {
			Identity controllerId(RR->topology->getIdentity(this->controller()));
			if (controllerId) {
				if (nc->fromDictionary(*dict)) {
					this->setConfiguration(*nc,true);
				} else {
					TRACE("error parsing new config with length %u: deserialization of NetworkConfig failed (certificate error?)",(unsigned int)newConfig.length());
				}
			}
			delete nc;
			delete dict;
		} catch ( ... ) {
			TRACE("error parsing new config with length %u: unexpected exception",(unsigned int)newConfig.length());
			delete nc;
			delete dict;
			throw;
		}
	}
}

void Network::requestConfiguration()
{
	// Sanity limit: do not request more often than once per second
	const uint64_t now = RR->node->now();
	if ((now - _lastRequestedConfiguration) < 1000ULL)
		return;
	_lastRequestedConfiguration = RR->node->now();

	const Address ctrl(controller());

	Dictionary<ZT_NETWORKCONFIG_METADATA_DICT_CAPACITY> rmd;
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_VERSION,(uint64_t)ZT_NETWORKCONFIG_VERSION);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_PROTOCOL_VERSION,(uint64_t)ZT_PROTO_VERSION);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MAJOR_VERSION,(uint64_t)ZEROTIER_ONE_VERSION_MAJOR);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MINOR_VERSION,(uint64_t)ZEROTIER_ONE_VERSION_MINOR);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_REVISION,(uint64_t)ZEROTIER_ONE_VERSION_REVISION);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_MAX_NETWORK_RULES,(uint64_t)ZT_MAX_NETWORK_RULES);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_MAX_NETWORK_CAPABILITIES,(uint64_t)ZT_MAX_NETWORK_CAPABILITIES);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_MAX_CAPABILITY_RULES,(uint64_t)ZT_MAX_CAPABILITY_RULES);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_MAX_NETWORK_TAGS,(uint64_t)ZT_MAX_NETWORK_TAGS);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_FLAGS,(uint64_t)0);
	rmd.add(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_RULES_ENGINE_REV,(uint64_t)ZT_RULES_ENGINE_REVISION);

	if (ctrl == RR->identity.address()) {
		if (RR->localNetworkController) {
			NetworkConfig nconf;
			switch(RR->localNetworkController->doNetworkConfigRequest(InetAddress(),RR->identity,RR->identity,_id,rmd,nconf)) {
				case NetworkController::NETCONF_QUERY_OK:
					this->setConfiguration(nconf,true);
					return;
				case NetworkController::NETCONF_QUERY_OBJECT_NOT_FOUND:
					this->setNotFound();
					return;
				case NetworkController::NETCONF_QUERY_ACCESS_DENIED:
					this->setAccessDenied();
					return;
				default:
					return;
			}
		} else {
			this->setNotFound();
			return;
		}
	}

	TRACE("requesting netconf for network %.16llx from controller %s",(unsigned long long)_id,ctrl.toString().c_str());

	Packet outp(ctrl,RR->identity.address(),Packet::VERB_NETWORK_CONFIG_REQUEST);
	outp.append((uint64_t)_id);
	const unsigned int rmdSize = rmd.sizeBytes();
	outp.append((uint16_t)rmdSize);
	outp.append((const void *)rmd.data(),rmdSize);
	if (_config) {
		outp.append((uint64_t)_config.revision);
		outp.append((uint64_t)_config.timestamp);
	} else {
		outp.append((unsigned char)0,16);
	}
	outp.compress();
	RR->sw->send(outp,true);

	// Expect replies with this in-re packet ID
	_inboundConfigPacketId = outp.packetId();
	_inboundConfigChunks.clear();
}

void Network::clean()
{
	const uint64_t now = RR->node->now();
	Mutex::Lock _l(_lock);

	if (_destroyed)
		return;

	{
		Hashtable< MulticastGroup,uint64_t >::Iterator i(_multicastGroupsBehindMe);
		MulticastGroup *mg = (MulticastGroup *)0;
		uint64_t *ts = (uint64_t *)0;
		while (i.next(mg,ts)) {
			if ((now - *ts) > (ZT_MULTICAST_LIKE_EXPIRE * 2))
				_multicastGroupsBehindMe.erase(*mg);
		}
	}

	{
		Address *a = (Address *)0;
		Membership *m = (Membership *)0;
		Hashtable<Address,Membership>::Iterator i(_memberships);
		while (i.next(a,m)) {
			if ((now - m->clean(now)) > ZT_MEMBERSHIP_EXPIRATION_TIME)
				_memberships.erase(*a);
		}
	}
}

void Network::learnBridgeRoute(const MAC &mac,const Address &addr)
{
	Mutex::Lock _l(_lock);
	_remoteBridgeRoutes[mac] = addr;

	// Anti-DOS circuit breaker to prevent nodes from spamming us with absurd numbers of bridge routes
	while (_remoteBridgeRoutes.size() > ZT_MAX_BRIDGE_ROUTES) {
		Hashtable< Address,unsigned long > counts;
		Address maxAddr;
		unsigned long maxCount = 0;

		MAC *m = (MAC *)0;
		Address *a = (Address *)0;

		// Find the address responsible for the most entries
		{
			Hashtable<MAC,Address>::Iterator i(_remoteBridgeRoutes);
			while (i.next(m,a)) {
				const unsigned long c = ++counts[*a];
				if (c > maxCount) {
					maxCount = c;
					maxAddr = *a;
				}
			}
		}

		// Kill this address from our table, since it's most likely spamming us
		{
			Hashtable<MAC,Address>::Iterator i(_remoteBridgeRoutes);
			while (i.next(m,a)) {
				if (*a == maxAddr)
					_remoteBridgeRoutes.erase(*m);
			}
		}
	}
}

void Network::learnBridgedMulticastGroup(const MulticastGroup &mg,uint64_t now)
{
	Mutex::Lock _l(_lock);
	const unsigned long tmp = (unsigned long)_multicastGroupsBehindMe.size();
	_multicastGroupsBehindMe.set(mg,now);
	if (tmp != _multicastGroupsBehindMe.size())
		_announceMulticastGroups();
}

void Network::destroy()
{
	Mutex::Lock _l(_lock);
	_destroyed = true;
}

ZT_VirtualNetworkStatus Network::_status() const
{
	// assumes _lock is locked
	if (_portError)
		return ZT_NETWORK_STATUS_PORT_ERROR;
	switch(_netconfFailure) {
		case NETCONF_FAILURE_ACCESS_DENIED:
			return ZT_NETWORK_STATUS_ACCESS_DENIED;
		case NETCONF_FAILURE_NOT_FOUND:
			return ZT_NETWORK_STATUS_NOT_FOUND;
		case NETCONF_FAILURE_NONE:
			return ((_config) ? ZT_NETWORK_STATUS_OK : ZT_NETWORK_STATUS_REQUESTING_CONFIGURATION);
		default:
			return ZT_NETWORK_STATUS_PORT_ERROR;
	}
}

void Network::_externalConfig(ZT_VirtualNetworkConfig *ec) const
{
	// assumes _lock is locked
	ec->nwid = _id;
	ec->mac = _mac.toInt();
	if (_config)
		Utils::scopy(ec->name,sizeof(ec->name),_config.name);
	else ec->name[0] = (char)0;
	ec->status = _status();
	ec->type = (_config) ? (_config.isPrivate() ? ZT_NETWORK_TYPE_PRIVATE : ZT_NETWORK_TYPE_PUBLIC) : ZT_NETWORK_TYPE_PRIVATE;
	ec->mtu = ZT_IF_MTU;
	ec->dhcp = 0;
	std::vector<Address> ab(_config.activeBridges());
	ec->bridge = ((_config.allowPassiveBridging())||(std::find(ab.begin(),ab.end(),RR->identity.address()) != ab.end())) ? 1 : 0;
	ec->broadcastEnabled = (_config) ? (_config.enableBroadcast() ? 1 : 0) : 0;
	ec->portError = _portError;
	ec->netconfRevision = (_config) ? (unsigned long)_config.revision : 0;

	ec->assignedAddressCount = 0;
	for(unsigned int i=0;i<ZT_MAX_ZT_ASSIGNED_ADDRESSES;++i) {
		if (i < _config.staticIpCount) {
			memcpy(&(ec->assignedAddresses[i]),&(_config.staticIps[i]),sizeof(struct sockaddr_storage));
			++ec->assignedAddressCount;
		} else {
			memset(&(ec->assignedAddresses[i]),0,sizeof(struct sockaddr_storage));
		}
	}

	ec->routeCount = 0;
	for(unsigned int i=0;i<ZT_MAX_NETWORK_ROUTES;++i) {
		if (i < _config.routeCount) {
			memcpy(&(ec->routes[i]),&(_config.routes[i]),sizeof(ZT_VirtualNetworkRoute));
			++ec->routeCount;
		} else {
			memset(&(ec->routes[i]),0,sizeof(ZT_VirtualNetworkRoute));
		}
	}
}

bool Network::_isAllowed(const SharedPtr<Peer> &peer) const
{
	// Assumes _lock is locked
	try {
		if (_config) {
			const Membership *const m = _memberships.get(peer->address());
			if (m)
				return m->isAllowedOnNetwork(_config);
		}
	} catch ( ... ) {
		TRACE("isAllowed() check failed for peer %s: unexpected exception",peer->address().toString().c_str());
	}
	return false;
}

class _MulticastAnnounceAll
{
public:
	_MulticastAnnounceAll(const RuntimeEnvironment *renv,Network *nw) :
		_now(renv->node->now()),
		_controller(nw->controller()),
		_network(nw),
		_anchors(nw->config().anchors()),
		_upstreamAddresses(renv->topology->upstreamAddresses())
	{}
	inline void operator()(Topology &t,const SharedPtr<Peer> &p)
	{
		if ( (_network->_isAllowed(p)) || // FIXME: this causes multicast LIKEs for public networks to get spammed, which isn't terrible but is a bit stupid
		     (p->address() == _controller) ||
		     (std::find(_upstreamAddresses.begin(),_upstreamAddresses.end(),p->address()) != _upstreamAddresses.end()) ||
				 (std::find(_anchors.begin(),_anchors.end(),p->address()) != _anchors.end()) ) {
			peers.push_back(p);
		}
	}
	std::vector< SharedPtr<Peer> > peers;
private:
	const uint64_t _now;
	const Address _controller;
	Network *const _network;
	const std::vector<Address> _anchors;
	const std::vector<Address> _upstreamAddresses;
};
void Network::_announceMulticastGroups()
{
	// Assumes _lock is locked
	std::vector<MulticastGroup> allMulticastGroups(_allMulticastGroups());
	_MulticastAnnounceAll gpfunc(RR,this);
	RR->topology->eachPeer<_MulticastAnnounceAll &>(gpfunc);
	for(std::vector< SharedPtr<Peer> >::const_iterator i(gpfunc.peers.begin());i!=gpfunc.peers.end();++i)
		_announceMulticastGroupsTo(*i,allMulticastGroups);
}

void Network::_announceMulticastGroupsTo(const SharedPtr<Peer> &peer,const std::vector<MulticastGroup> &allMulticastGroups)
{
	// Assumes _lock is locked

	// Anyone we announce multicast groups to will need our COM to authenticate GATHER requests.
	{
		Membership *m = _memberships.get(peer->address());
		if (m)
			m->sendCredentialsIfNeeded(RR,RR->node->now(),peer->address(),_config,(const Capability *)0);
	}

	Packet outp(peer->address(),RR->identity.address(),Packet::VERB_MULTICAST_LIKE);

	for(std::vector<MulticastGroup>::const_iterator mg(allMulticastGroups.begin());mg!=allMulticastGroups.end();++mg) {
		if ((outp.size() + 24) >= ZT_PROTO_MAX_PACKET_LENGTH) {
			outp.compress();
			RR->sw->send(outp,true);
			outp.reset(peer->address(),RR->identity.address(),Packet::VERB_MULTICAST_LIKE);
		}

		// network ID, MAC, ADI
		outp.append((uint64_t)_id);
		mg->mac().appendTo(outp);
		outp.append((uint32_t)mg->adi());
	}

	if (outp.size() > ZT_PROTO_MIN_PACKET_LENGTH) {
		outp.compress();
		RR->sw->send(outp,true);
	}
}

std::vector<MulticastGroup> Network::_allMulticastGroups() const
{
	// Assumes _lock is locked

	std::vector<MulticastGroup> mgs;
	mgs.reserve(_myMulticastGroups.size() + _multicastGroupsBehindMe.size() + 1);
	mgs.insert(mgs.end(),_myMulticastGroups.begin(),_myMulticastGroups.end());
	_multicastGroupsBehindMe.appendKeys(mgs);
	if ((_config)&&(_config.enableBroadcast()))
		mgs.push_back(Network::BROADCAST);
	std::sort(mgs.begin(),mgs.end());
	mgs.erase(std::unique(mgs.begin(),mgs.end()),mgs.end());

	return mgs;
}

} // namespace ZeroTier