So we need to keep track of external surface per reporter, since some NATs assign different external IPs for each external destination. Keeping just one known surface could create a race condition.

This commit is contained in:
Adam Ierymenko 2015-05-04 18:34:30 -07:00
parent 625ddf41a7
commit b4b067bf12
5 changed files with 92 additions and 45 deletions

View File

@ -273,7 +273,7 @@ bool IncomingPacket::_doHELLO(const RuntimeEnvironment *RR)
trusted = true;
}
if (destAddr)
RR->sa->iam(id.address(),_remoteAddress,destAddr,trusted);
RR->sa->iam(id.address(),_remoteAddress,destAddr,trusted,RR->node->now());
Packet outp(id.address(),RR->identity.address(),Packet::VERB_OK);
@ -358,7 +358,7 @@ bool IncomingPacket::_doOK(const RuntimeEnvironment *RR,const SharedPtr<Peer> &p
trusted = true;
}
if (destAddr)
RR->sa->iam(peer->address(),_remoteAddress,destAddr,trusted);
RR->sa->iam(peer->address(),_remoteAddress,destAddr,trusted,RR->node->now());
} break;
case Packet::VERB_WHOIS: {

View File

@ -63,9 +63,6 @@ struct InetAddress : public sockaddr_storage
/**
* IP address scope
*
* Do not change these numeric index values without taking a look
* at SelfAwareness. Values 1-5 are mapped onto an array index.
*/
enum IpScope
{

View File

@ -264,6 +264,7 @@ ZT1_ResultCode Node::processBackgroundTasks(uint64_t now,volatile uint64_t *next
try {
RR->topology->clean(now);
RR->sa->clean(now);
} catch ( ... ) {
return ZT1_RESULT_FATAL_ERROR_INTERNAL;
}

View File

@ -37,6 +37,9 @@
#include "Packet.hpp"
#include "Peer.hpp"
// Entry timeout -- make it fairly long since this is just to prevent stale buildup
#define ZT_SELFAWARENESS_ENTRY_TIMEOUT 3600000
namespace ZeroTier {
class _ResetWithinScope
@ -64,53 +67,59 @@ private:
SelfAwareness::SelfAwareness(const RuntimeEnvironment *renv) :
RR(renv)
{
memset(_lastPhysicalAddress,0,sizeof(_lastPhysicalAddress));
}
SelfAwareness::~SelfAwareness()
{
}
void SelfAwareness::iam(const Address &reporter,const InetAddress &reporterPhysicalAddress,const InetAddress &myPhysicalAddress,bool trusted)
void SelfAwareness::iam(const Address &reporter,const InetAddress &reporterPhysicalAddress,const InetAddress &myPhysicalAddress,bool trusted,uint64_t now)
{
// This code depends on the numeric values assigned to scopes in InetAddress.hpp
const unsigned int scope = (unsigned int)myPhysicalAddress.ipScope();
if ((scope > 0)&&(scope < (unsigned int)InetAddress::IP_SCOPE_LOOPBACK)) {
if ( (!trusted) && ((scope == (unsigned int)InetAddress::IP_SCOPE_GLOBAL)||(scope != (unsigned int)reporterPhysicalAddress.ipScope())) ) {
/* For now only trusted peers are permitted to inform us of changes to
* our global Internet IP or to changes of NATed IPs. We'll let peers on
* private, shared, or link-local networks inform us of changes as long
* as they too are at the same scope. This discrimination avoids a DoS
* attack in which an attacker could force us to reset our connections. */
const InetAddress::IpScope scope = myPhysicalAddress.ipScope();
switch(scope) {
case InetAddress::IP_SCOPE_NONE:
case InetAddress::IP_SCOPE_LOOPBACK:
case InetAddress::IP_SCOPE_MULTICAST:
return;
} else {
Mutex::Lock _l(_lock);
InetAddress &lastPhy = _lastPhysicalAddress[scope - 1];
if (!lastPhy) {
TRACE("learned physical address %s for scope %u from reporter %s(%s) (replaced <null>)",myPhysicalAddress.toString().c_str(),scope,reporter.toString().c_str(),reporterPhysicalAddress.toString().c_str());
lastPhy = myPhysicalAddress;
} else if (lastPhy != myPhysicalAddress) {
TRACE("learned physical address %s for scope %u from reporter %s(%s) (replaced %s, resetting within scope)",myPhysicalAddress.toString().c_str(),scope,reporter.toString().c_str(),reporterPhysicalAddress.toString().c_str(),lastPhy.toString().c_str());
lastPhy = myPhysicalAddress;
uint64_t now = RR->node->now();
case InetAddress::IP_SCOPE_GLOBAL:
if ((!trusted)||(scope != reporterPhysicalAddress.ipScope()))
return;
break;
default:
if (scope != reporterPhysicalAddress.ipScope())
return;
break;
}
_ResetWithinScope rset(RR,now,(InetAddress::IpScope)scope);
RR->topology->eachPeer<_ResetWithinScope &>(rset);
Mutex::Lock _l(_phy_m);
// For all peers for whom we forgot an address, send a packet indirectly if
// they are still considered alive so that we will re-establish direct links.
SharedPtr<Peer> sn(RR->topology->getBestSupernode());
if (sn) {
Path *snp = sn->getBestPath(now);
if (snp) {
for(std::vector< SharedPtr<Peer> >::const_iterator p(rset.peersReset.begin());p!=rset.peersReset.end();++p) {
if ((*p)->alive(now)) {
TRACE("sending indirect NOP to %s via %s(%s) to re-establish link",(*p)->address().toString().c_str(),sn->address().toString().c_str(),snp->address().toString().c_str());
Packet outp((*p)->address(),RR->identity.address(),Packet::VERB_NOP);
outp.armor((*p)->key(),true);
snp->send(RR,outp.data(),outp.size(),now);
}
}
PhySurfaceEntry &entry = _phy[PhySurfaceKey(reporter,scope)];
if (!entry.ts) {
entry.mySurface = myPhysicalAddress;
entry.ts = now;
TRACE("learned physical address %s for scope %u as seen from %s(%s) (replaced <null>)",myPhysicalAddress.toString().c_str(),(unsigned int)scope,reporter.toString().c_str(),reporterPhysicalAddress.toString().c_str());
} else if (entry.mySurface != myPhysicalAddress) {
entry.mySurface = myPhysicalAddress;
entry.ts = now;
TRACE("learned physical address %s for scope %u as seen from %s(%s) (replaced %s, resetting all in scope)",myPhysicalAddress.toString().c_str(),(unsigned int)scope,reporter.toString().c_str(),reporterPhysicalAddress.toString().c_str(),entry.mySurface.toString().c_str());
_ResetWithinScope rset(RR,now,(InetAddress::IpScope)scope);
RR->topology->eachPeer<_ResetWithinScope &>(rset);
// For all peers for whom we forgot an address, send a packet indirectly if
// they are still considered alive so that we will re-establish direct links.
SharedPtr<Peer> sn(RR->topology->getBestSupernode());
if (sn) {
Path *snp = sn->getBestPath(now);
if (snp) {
for(std::vector< SharedPtr<Peer> >::const_iterator p(rset.peersReset.begin());p!=rset.peersReset.end();++p) {
if ((*p)->alive(now)) {
TRACE("sending indirect NOP to %s via %s(%s) to re-establish link",(*p)->address().toString().c_str(),sn->address().toString().c_str(),snp->address().toString().c_str());
Packet outp((*p)->address(),RR->identity.address(),Packet::VERB_NOP);
outp.armor((*p)->key(),true);
snp->send(RR,outp.data(),outp.size(),now);
}
}
}
@ -118,4 +127,14 @@ void SelfAwareness::iam(const Address &reporter,const InetAddress &reporterPhysi
}
}
void SelfAwareness::clean(uint64_t now)
{
Mutex::Lock _l(_phy_m);
for(std::map< PhySurfaceKey,PhySurfaceEntry >::iterator p(_phy.begin());p!=_phy.end();) {
if ((now - p->second.ts) >= ZT_SELFAWARENESS_ENTRY_TIMEOUT)
_phy.erase(p++);
else ++p;
}
}
} // namespace ZeroTier

View File

@ -28,6 +28,8 @@
#ifndef ZT_SELFAWARENESS_HPP
#define ZT_SELFAWARENESS_HPP
#include <map>
#include "InetAddress.hpp"
#include "Address.hpp"
#include "Mutex.hpp"
@ -52,13 +54,41 @@ public:
* @param reporterPhysicalAddress Physical address that reporting peer seems to have
* @param myPhysicalAddress Physical address that peer says we have
* @param trusted True if this peer is trusted as an authority to inform us of external address changes
* @param now Current time
*/
void iam(const Address &reporter,const InetAddress &reporterPhysicalAddress,const InetAddress &myPhysicalAddress,bool trusted);
void iam(const Address &reporter,const InetAddress &reporterPhysicalAddress,const InetAddress &myPhysicalAddress,bool trusted,uint64_t now);
/**
* Clean up database periodically
*
* @param now Current time
*/
void clean(uint64_t now);
private:
struct PhySurfaceKey
{
Address reporter;
InetAddress::IpScope scope;
PhySurfaceKey() : reporter(),scope(InetAddress::IP_SCOPE_NONE) {}
PhySurfaceKey(const Address &r,InetAddress::IpScope s) : reporter(r),scope(s) {}
inline bool operator<(const PhySurfaceKey &k) const throw() { return ((reporter < k.reporter) ? true : ((reporter == k.reporter) ? ((int)scope < (int)k.scope) : false)); }
inline bool operator==(const PhySurfaceKey &k) const throw() { return ((reporter == k.reporter)&&(scope == k.scope)); }
};
struct PhySurfaceEntry
{
InetAddress mySurface;
uint64_t ts;
PhySurfaceEntry() : mySurface(),ts(0) {}
PhySurfaceEntry(const InetAddress &a,const uint64_t t) : mySurface(a),ts(t) {}
};
const RuntimeEnvironment *RR;
Mutex _lock;
InetAddress _lastPhysicalAddress[5]; // 5 == the number of address classes we care about, see InetAddress.hpp and SelfAwareness.cpp
std::map< PhySurfaceKey,PhySurfaceEntry > _phy;
Mutex _phy_m;
};
} // namespace ZeroTier