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/*
* 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_MULTICASTER_HPP
#define ZT_MULTICASTER_HPP
#include <stdint.h>
#include <string.h>
#include <map>
#include <vector>
#include <list>
#include "Constants.hpp"
#include "Hashtable.hpp"
#include "Address.hpp"
#include "MAC.hpp"
#include "MulticastGroup.hpp"
#include "OutboundMulticast.hpp"
#include "Utils.hpp"
#include "Mutex.hpp"
#include "NonCopyable.hpp"
namespace ZeroTier {
class RuntimeEnvironment;
class CertificateOfMembership;
class Packet;
/**
* Database of known multicast peers within a network
*/
class Multicaster : NonCopyable
{
private:
struct Key
{
Key() : nwid(0),mg() {}
Key(uint64_t n,const MulticastGroup &g) : nwid(n),mg(g) {}
uint64_t nwid;
MulticastGroup mg;
inline bool operator==(const Key &k) const throw() { return ((nwid == k.nwid)&&(mg == k.mg)); }
inline unsigned long hashCode() const throw() { return (mg.hashCode() ^ (unsigned long)(nwid ^ (nwid >> 32))); }
};
struct MulticastGroupMember
{
MulticastGroupMember() {}
MulticastGroupMember(const Address &a,uint64_t ts) : address(a),timestamp(ts) {}
Address address;
uint64_t timestamp; // time of last notification
};
struct MulticastGroupStatus
{
MulticastGroupStatus() : lastExplicitGather(0) {}
uint64_t lastExplicitGather;
std::list<OutboundMulticast> txQueue; // pending outbound multicasts
std::vector<MulticastGroupMember> members; // members of this group
};
public:
Multicaster(const RuntimeEnvironment *renv);
~Multicaster();
/**
* Add or update a member in a multicast group
*
* @param now Current time
* @param nwid Network ID
* @param mg Multicast group
* @param member New member address
*/
inline void add(uint64_t now,uint64_t nwid,const MulticastGroup &mg,const Address &member)
{
Mutex::Lock _l(_groups_m);
_add(now,nwid,mg,_groups[Multicaster::Key(nwid,mg)],member);
}
/**
* Add multiple addresses from a binary array of 5-byte address fields
*
* It's up to the caller to check bounds on the array before calling this.
*
* @param now Current time
* @param nwid Network ID
* @param mg Multicast group
* @param addresses Raw binary addresses in big-endian format, as a series of 5-byte fields
* @param count Number of addresses
* @param totalKnown Total number of known addresses as reported by peer
*/
void addMultiple(uint64_t now,uint64_t nwid,const MulticastGroup &mg,const void *addresses,unsigned int count,unsigned int totalKnown);
/**
* Remove a multicast group member (if present)
*
* @param nwid Network ID
* @param mg Multicast group
* @param member Member to unsubscribe
*/
void remove(uint64_t nwid,const MulticastGroup &mg,const Address &member);
/**
* Append gather results to a packet by choosing registered multicast recipients at random
*
* This appends the following fields to the packet:
* <[4] 32-bit total number of known members in this multicast group>
* <[2] 16-bit number of members enumerated in this packet>
* <[...] series of 5-byte ZeroTier addresses of enumerated members>
*
* If zero is returned, the first two fields will still have been appended.
*
* @param queryingPeer Peer asking for gather (to skip in results)
* @param nwid Network ID
* @param mg Multicast group
* @param appendTo Packet to append to
* @param limit Maximum number of 5-byte addresses to append
* @return Number of addresses appended
* @throws std::out_of_range Buffer overflow writing to packet
*/
unsigned int gather(const Address &queryingPeer,uint64_t nwid,const MulticastGroup &mg,Buffer<ZT_PROTO_MAX_PACKET_LENGTH> &appendTo,unsigned int limit) const;
/**
* Get subscribers to a multicast group
*
* @param nwid Network ID
* @param mg Multicast group
*/
std::vector<Address> getMembers(uint64_t nwid,const MulticastGroup &mg,unsigned int limit) const;
/**
* Send a multicast
*
* @param limit Multicast limit
* @param now Current time
* @param nwid Network ID
* @param disableCompression Disable packet payload compression?
* @param alwaysSendTo Send to these peers first and even if not included in subscriber list
* @param mg Multicast group
* @param src Source Ethernet MAC address or NULL to skip in packet and compute from ZT address (non-bridged mode)
* @param etherType Ethernet frame type
* @param data Packet data
* @param len Length of packet data
*/
void send(
unsigned int limit,
uint64_t now,
uint64_t nwid,
bool disableCompression,
const std::vector<Address> &alwaysSendTo,
const MulticastGroup &mg,
const MAC &src,
unsigned int etherType,
const void *data,
unsigned int len);
/**
* Clean up and resort database
*
* @param RR Runtime environment
* @param now Current time
*/
void clean(uint64_t now);
/**
* Add an authorization credential
*
* The Multicaster keeps its own track of when valid credentials of network
* membership are presented. This allows it to control MULTICAST_LIKE
* GATHER authorization for networks this node does not belong to.
*
* @param com Certificate of membership
* @param alreadyValidated If true, COM has already been checked and found to be valid and signed
*/
void addCredential(const CertificateOfMembership &com,bool alreadyValidated);
/**
* Check authorization for GATHER and LIKE for non-network-members
*
* @param a Address of peer
* @param nwid Network ID
* @param now Current time
* @return True if GATHER and LIKE should be allowed
*/
bool cacheAuthorized(const Address &a,const uint64_t nwid,const uint64_t now) const
{
Mutex::Lock _l(_gatherAuth_m);
const uint64_t *p = _gatherAuth.get(_GatherAuthKey(nwid,a));
return ((p)&&((now - *p) < ZT_MULTICAST_CREDENTIAL_EXPIRATON));
}
private:
void _add(uint64_t now,uint64_t nwid,const MulticastGroup &mg,MulticastGroupStatus &gs,const Address &member);
const RuntimeEnvironment *RR;
Hashtable<Multicaster::Key,MulticastGroupStatus> _groups;
Mutex _groups_m;
struct _GatherAuthKey
{
_GatherAuthKey() : member(0),networkId(0) {}
_GatherAuthKey(const uint64_t nwid,const Address &a) : member(a.toInt()),networkId(nwid) {}
inline unsigned long hashCode() const { return (unsigned long)(member ^ networkId); }
inline bool operator==(const _GatherAuthKey &k) const { return ((member == k.member)&&(networkId == k.networkId)); }
uint64_t member;
uint64_t networkId;
};
Hashtable< _GatherAuthKey,uint64_t > _gatherAuth;
Mutex _gatherAuth_m;
};
} // namespace ZeroTier
#endif
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