didyouexpectthat_zerotierone/node/Multicaster.cpp
2018-01-12 18:20:00 -08:00

396 lines
12 KiB
C++

/*
* 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 <algorithm>
#include "Constants.hpp"
#include "RuntimeEnvironment.hpp"
#include "SharedPtr.hpp"
#include "Multicaster.hpp"
#include "Topology.hpp"
#include "Switch.hpp"
#include "Packet.hpp"
#include "Peer.hpp"
#include "C25519.hpp"
#include "CertificateOfMembership.hpp"
#include "Node.hpp"
namespace ZeroTier {
Multicaster::Multicaster(const RuntimeEnvironment *renv) :
RR(renv),
_groups(256),
_gatherAuth(256)
{
}
Multicaster::~Multicaster()
{
}
void Multicaster::addMultiple(void *tPtr,uint64_t now,uint64_t nwid,const MulticastGroup &mg,const void *addresses,unsigned int count,unsigned int totalKnown)
{
const unsigned char *p = (const unsigned char *)addresses;
const unsigned char *e = p + (5 * count);
Mutex::Lock _l(_groups_m);
MulticastGroupStatus &gs = _groups[Multicaster::Key(nwid,mg)];
while (p != e) {
_add(tPtr,now,nwid,mg,gs,Address(p,5));
p += 5;
}
}
void Multicaster::remove(uint64_t nwid,const MulticastGroup &mg,const Address &member)
{
Mutex::Lock _l(_groups_m);
MulticastGroupStatus *s = _groups.get(Multicaster::Key(nwid,mg));
if (s) {
for(std::vector<MulticastGroupMember>::iterator m(s->members.begin());m!=s->members.end();++m) {
if (m->address == member) {
s->members.erase(m);
break;
}
}
}
}
unsigned int Multicaster::gather(const Address &queryingPeer,uint64_t nwid,const MulticastGroup &mg,Buffer<ZT_PROTO_MAX_PACKET_LENGTH> &appendTo,unsigned int limit) const
{
unsigned char *p;
unsigned int added = 0,i,k,rptr,totalKnown = 0;
uint64_t a,picked[(ZT_PROTO_MAX_PACKET_LENGTH / 5) + 2];
if (!limit)
return 0;
else if (limit > 0xffff)
limit = 0xffff;
const unsigned int totalAt = appendTo.size();
appendTo.addSize(4); // sizeof(uint32_t)
const unsigned int addedAt = appendTo.size();
appendTo.addSize(2); // sizeof(uint16_t)
{ // Return myself if I am a member of this group
SharedPtr<Network> network(RR->node->network(nwid));
if ((network)&&(network->subscribedToMulticastGroup(mg,true))) {
RR->identity.address().appendTo(appendTo);
++totalKnown;
++added;
}
}
Mutex::Lock _l(_groups_m);
const MulticastGroupStatus *s = _groups.get(Multicaster::Key(nwid,mg));
if ((s)&&(!s->members.empty())) {
totalKnown += (unsigned int)s->members.size();
// Members are returned in random order so that repeated gather queries
// will return different subsets of a large multicast group.
k = 0;
while ((added < limit)&&(k < s->members.size())&&((appendTo.size() + ZT_ADDRESS_LENGTH) <= ZT_UDP_DEFAULT_PAYLOAD_MTU)) {
rptr = (unsigned int)RR->node->prng();
restart_member_scan:
a = s->members[rptr % (unsigned int)s->members.size()].address.toInt();
for(i=0;i<k;++i) {
if (picked[i] == a) {
++rptr;
goto restart_member_scan;
}
}
picked[k++] = a;
if (queryingPeer.toInt() != a) { // do not return the peer that is making the request as a result
p = (unsigned char *)appendTo.appendField(ZT_ADDRESS_LENGTH);
*(p++) = (unsigned char)((a >> 32) & 0xff);
*(p++) = (unsigned char)((a >> 24) & 0xff);
*(p++) = (unsigned char)((a >> 16) & 0xff);
*(p++) = (unsigned char)((a >> 8) & 0xff);
*p = (unsigned char)(a & 0xff);
++added;
}
}
}
appendTo.setAt(totalAt,(uint32_t)totalKnown);
appendTo.setAt(addedAt,(uint16_t)added);
//TRACE("..MC Multicaster::gather() attached %u of %u peers for %.16llx/%s (2)",n,(unsigned int)(gs->second.members.size() - skipped),nwid,mg.toString().c_str());
return added;
}
std::vector<Address> Multicaster::getMembers(uint64_t nwid,const MulticastGroup &mg,unsigned int limit) const
{
std::vector<Address> ls;
Mutex::Lock _l(_groups_m);
const MulticastGroupStatus *s = _groups.get(Multicaster::Key(nwid,mg));
if (!s)
return ls;
for(std::vector<MulticastGroupMember>::const_reverse_iterator m(s->members.rbegin());m!=s->members.rend();++m) {
ls.push_back(m->address);
if (ls.size() >= limit)
break;
}
return ls;
}
void Multicaster::send(
void *tPtr,
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)
{
unsigned long idxbuf[8194];
unsigned long *indexes = idxbuf;
try {
Mutex::Lock _l(_groups_m);
MulticastGroupStatus &gs = _groups[Multicaster::Key(nwid,mg)];
if (!gs.members.empty()) {
// Allocate a memory buffer if group is monstrous
if (gs.members.size() > (sizeof(idxbuf) / sizeof(unsigned long)))
indexes = new unsigned long[gs.members.size()];
// Generate a random permutation of member indexes
for(unsigned long i=0;i<gs.members.size();++i)
indexes[i] = i;
for(unsigned long i=(unsigned long)gs.members.size()-1;i>0;--i) {
unsigned long j = (unsigned long)RR->node->prng() % (i + 1);
unsigned long tmp = indexes[j];
indexes[j] = indexes[i];
indexes[i] = tmp;
}
}
if (gs.members.size() >= limit) {
// Skip queue if we already have enough members to complete the send operation
OutboundMulticast out;
out.init(
RR,
now,
nwid,
disableCompression,
limit,
1, // we'll still gather a little from peers to keep multicast list fresh
src,
mg,
etherType,
data,
len);
unsigned int count = 0;
for(std::vector<Address>::const_iterator ast(alwaysSendTo.begin());ast!=alwaysSendTo.end();++ast) {
if (*ast != RR->identity.address()) {
out.sendOnly(RR,tPtr,*ast); // optimization: don't use dedup log if it's a one-pass send
if (++count >= limit)
break;
}
}
unsigned long idx = 0;
while ((count < limit)&&(idx < gs.members.size())) {
Address ma(gs.members[indexes[idx++]].address);
if (std::find(alwaysSendTo.begin(),alwaysSendTo.end(),ma) == alwaysSendTo.end()) {
out.sendOnly(RR,tPtr,ma); // optimization: don't use dedup log if it's a one-pass send
++count;
}
}
} else {
unsigned int gatherLimit = (limit - (unsigned int)gs.members.size()) + 1;
if ((gs.members.empty())||((now - gs.lastExplicitGather) >= ZT_MULTICAST_EXPLICIT_GATHER_DELAY)) {
gs.lastExplicitGather = now;
Address explicitGatherPeers[16];
unsigned int numExplicitGatherPeers = 0;
SharedPtr<Peer> bestRoot(RR->topology->getUpstreamPeer());
if (bestRoot)
explicitGatherPeers[numExplicitGatherPeers++] = bestRoot->address();
explicitGatherPeers[numExplicitGatherPeers++] = Network::controllerFor(nwid);
SharedPtr<Network> network(RR->node->network(nwid));
if (network) {
std::vector<Address> anchors(network->config().anchors());
for(std::vector<Address>::const_iterator a(anchors.begin());a!=anchors.end();++a) {
if (*a != RR->identity.address()) {
explicitGatherPeers[numExplicitGatherPeers++] = *a;
if (numExplicitGatherPeers == 16)
break;
}
}
}
for(unsigned int k=0;k<numExplicitGatherPeers;++k) {
const CertificateOfMembership *com = (network) ? ((network->config().com) ? &(network->config().com) : (const CertificateOfMembership *)0) : (const CertificateOfMembership *)0;
Packet outp(explicitGatherPeers[k],RR->identity.address(),Packet::VERB_MULTICAST_GATHER);
outp.append(nwid);
outp.append((uint8_t)((com) ? 0x01 : 0x00));
mg.mac().appendTo(outp);
outp.append((uint32_t)mg.adi());
outp.append((uint32_t)gatherLimit);
if (com)
com->serialize(outp);
RR->node->expectReplyTo(outp.packetId());
RR->sw->send(tPtr,outp,true);
}
}
gs.txQueue.push_back(OutboundMulticast());
OutboundMulticast &out = gs.txQueue.back();
out.init(
RR,
now,
nwid,
disableCompression,
limit,
gatherLimit,
src,
mg,
etherType,
data,
len);
unsigned int count = 0;
for(std::vector<Address>::const_iterator ast(alwaysSendTo.begin());ast!=alwaysSendTo.end();++ast) {
if (*ast != RR->identity.address()) {
out.sendAndLog(RR,tPtr,*ast);
if (++count >= limit)
break;
}
}
unsigned long idx = 0;
while ((count < limit)&&(idx < gs.members.size())) {
Address ma(gs.members[indexes[idx++]].address);
if (std::find(alwaysSendTo.begin(),alwaysSendTo.end(),ma) == alwaysSendTo.end()) {
out.sendAndLog(RR,tPtr,ma);
++count;
}
}
}
} catch ( ... ) {} // this is a sanity check to catch any failures and make sure indexes[] still gets deleted
// Free allocated memory buffer if any
if (indexes != idxbuf)
delete [] indexes;
}
void Multicaster::clean(uint64_t now)
{
{
Mutex::Lock _l(_groups_m);
Multicaster::Key *k = (Multicaster::Key *)0;
MulticastGroupStatus *s = (MulticastGroupStatus *)0;
Hashtable<Multicaster::Key,MulticastGroupStatus>::Iterator mm(_groups);
while (mm.next(k,s)) {
for(std::list<OutboundMulticast>::iterator tx(s->txQueue.begin());tx!=s->txQueue.end();) {
if ((tx->expired(now))||(tx->atLimit()))
s->txQueue.erase(tx++);
else ++tx;
}
unsigned long count = 0;
{
std::vector<MulticastGroupMember>::iterator reader(s->members.begin());
std::vector<MulticastGroupMember>::iterator writer(reader);
while (reader != s->members.end()) {
if ((now - reader->timestamp) < ZT_MULTICAST_LIKE_EXPIRE) {
*writer = *reader;
++writer;
++count;
}
++reader;
}
}
if (count) {
s->members.resize(count);
} else if (s->txQueue.empty()) {
_groups.erase(*k);
} else {
s->members.clear();
}
}
}
{
Mutex::Lock _l(_gatherAuth_m);
_GatherAuthKey *k = (_GatherAuthKey *)0;
uint64_t *ts = NULL;
Hashtable<_GatherAuthKey,uint64_t>::Iterator i(_gatherAuth);
while (i.next(k,ts)) {
if ((now - *ts) >= ZT_MULTICAST_CREDENTIAL_EXPIRATON)
_gatherAuth.erase(*k);
}
}
}
void Multicaster::addCredential(void *tPtr,const CertificateOfMembership &com,bool alreadyValidated)
{
if ((alreadyValidated)||(com.verify(RR,tPtr) == 0)) {
Mutex::Lock _l(_gatherAuth_m);
_gatherAuth[_GatherAuthKey(com.networkId(),com.issuedTo())] = RR->node->now();
}
}
void Multicaster::_add(void *tPtr,uint64_t now,uint64_t nwid,const MulticastGroup &mg,MulticastGroupStatus &gs,const Address &member)
{
// assumes _groups_m is locked
// Do not add self -- even if someone else returns it
if (member == RR->identity.address())
return;
for(std::vector<MulticastGroupMember>::iterator m(gs.members.begin());m!=gs.members.end();++m) {
if (m->address == member) {
m->timestamp = now;
return;
}
}
gs.members.push_back(MulticastGroupMember(member,now));
//TRACE("..MC %s joined multicast group %.16llx/%s via %s",member.toString().c_str(),nwid,mg.toString().c_str(),((learnedFrom) ? learnedFrom.toString().c_str() : "(direct)"));
for(std::list<OutboundMulticast>::iterator tx(gs.txQueue.begin());tx!=gs.txQueue.end();) {
if (tx->atLimit())
gs.txQueue.erase(tx++);
else {
tx->sendIfNew(RR,tPtr,member);
if (tx->atLimit())
gs.txQueue.erase(tx++);
else ++tx;
}
}
}
} // namespace ZeroTier