i2pd/LeaseSet.cpp
2016-02-14 18:30:07 -05:00

219 lines
6.1 KiB
C++

#include <string.h>
#include "I2PEndian.h"
#include "Crypto.h"
#include "Log.h"
#include "Timestamp.h"
#include "NetDb.h"
#include "TunnelPool.h"
#include "LeaseSet.h"
namespace i2p
{
namespace data
{
LeaseSet::LeaseSet (const uint8_t * buf, size_t len, bool storeLeases):
m_IsValid (true), m_StoreLeases (storeLeases), m_ExpirationTime (0)
{
m_Buffer = new uint8_t[len];
memcpy (m_Buffer, buf, len);
m_BufferLen = len;
ReadFromBuffer ();
}
LeaseSet::LeaseSet (std::shared_ptr<const i2p::tunnel::TunnelPool> pool):
m_IsValid (true), m_StoreLeases (true), m_ExpirationTime (0)
{
if (!pool) return;
// header
auto localDestination = pool->GetLocalDestination ();
if (!localDestination)
{
m_Buffer = nullptr;
m_BufferLen = 0;
m_IsValid = false;
LogPrint (eLogError, "LeaseSet: Destination for local LeaseSet doesn't exist");
return;
}
m_Buffer = new uint8_t[MAX_LS_BUFFER_SIZE];
m_BufferLen = localDestination->GetIdentity ()->ToBuffer (m_Buffer, MAX_LS_BUFFER_SIZE);
memcpy (m_Buffer + m_BufferLen, localDestination->GetEncryptionPublicKey (), 256);
m_BufferLen += 256;
auto signingKeyLen = localDestination->GetIdentity ()->GetSigningPublicKeyLen ();
memset (m_Buffer + m_BufferLen, 0, signingKeyLen);
m_BufferLen += signingKeyLen;
int numTunnels = pool->GetNumInboundTunnels () + 2; // 2 backup tunnels
if (numTunnels > 16) numTunnels = 16; // 16 tunnels maximum
auto tunnels = pool->GetInboundTunnels (numTunnels);
m_Buffer[m_BufferLen] = tunnels.size (); // num leases
m_BufferLen++;
// leases
for (auto it: tunnels)
{
memcpy (m_Buffer + m_BufferLen, it->GetNextIdentHash (), 32);
m_BufferLen += 32; // gateway id
htobe32buf (m_Buffer + m_BufferLen, it->GetNextTunnelID ());
m_BufferLen += 4; // tunnel id
uint64_t ts = it->GetCreationTime () + i2p::tunnel::TUNNEL_EXPIRATION_TIMEOUT - i2p::tunnel::TUNNEL_EXPIRATION_THRESHOLD; // 1 minute before expiration
ts *= 1000; // in milliseconds
ts += rand () % 6; // + random milliseconds 0-5
if (ts > m_ExpirationTime) m_ExpirationTime = ts;
htobe64buf (m_Buffer + m_BufferLen, ts);
m_BufferLen += 8; // end date
}
// signature
localDestination->Sign (m_Buffer, m_BufferLen, m_Buffer + m_BufferLen);
m_BufferLen += localDestination->GetIdentity ()->GetSignatureLen ();
LogPrint (eLogDebug, "LeaseSet: Local LeaseSet of ", tunnels.size (), " leases created");
ReadFromBuffer ();
}
void LeaseSet::Update (const uint8_t * buf, size_t len)
{
if (len > m_BufferLen)
{
auto oldBuffer = m_Buffer;
m_Buffer = new uint8_t[len];
delete[] oldBuffer;
}
memcpy (m_Buffer, buf, len);
m_BufferLen = len;
ReadFromBuffer (false);
}
void LeaseSet::PopulateLeases ()
{
m_StoreLeases = true;
ReadFromBuffer (false);
}
void LeaseSet::ReadFromBuffer (bool readIdentity)
{
if (readIdentity || !m_Identity)
m_Identity = std::make_shared<IdentityEx>(m_Buffer, m_BufferLen);
size_t size = m_Identity->GetFullLen ();
if (size > m_BufferLen)
{
LogPrint (eLogError, "LeaseSet: identity length ", size, " exceeds buffer size ", m_BufferLen);
m_IsValid = false;
return;
}
memcpy (m_EncryptionKey, m_Buffer + size, 256);
size += 256; // encryption key
size += m_Identity->GetSigningPublicKeyLen (); // unused signing key
uint8_t num = m_Buffer[size];
size++; // num
LogPrint (eLogDebug, "LeaseSet: read num=", (int)num);
if (!num || num > MAX_NUM_LEASES)
{
LogPrint (eLogError, "LeaseSet: incorrect number of leases", (int)num);
m_IsValid = false;
return;
}
// reset existing leases
if (m_StoreLeases)
for (auto it: m_Leases)
it->isUpdated = false;
else
m_Leases.clear ();
// process leases
m_ExpirationTime = 0;
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
const uint8_t * leases = m_Buffer + size;
for (int i = 0; i < num; i++)
{
Lease lease;
lease.tunnelGateway = leases;
leases += 32; // gateway
lease.tunnelID = bufbe32toh (leases);
leases += 4; // tunnel ID
lease.endDate = bufbe64toh (leases);
leases += 8; // end date
if (ts < lease.endDate + LEASE_ENDDATE_THRESHOLD)
{
if (lease.endDate > m_ExpirationTime)
m_ExpirationTime = lease.endDate;
if (m_StoreLeases)
{
auto ret = m_Leases.insert (std::make_shared<Lease>(lease));
if (!ret.second) *(*ret.first) = lease; // update existing
(*ret.first)->isUpdated = true;
// check if lease's gateway is in our netDb
if (!netdb.FindRouter (lease.tunnelGateway))
{
// if not found request it
LogPrint (eLogInfo, "LeaseSet: Lease's tunnel gateway not found, requesting");
netdb.RequestDestination (lease.tunnelGateway);
}
}
}
else
LogPrint (eLogWarning, "LeaseSet: Lease is expired already ");
}
if (!m_ExpirationTime)
{
LogPrint (eLogWarning, "LeaseSet: all leases are expired. Dropped");
m_IsValid = false;
return;
}
m_ExpirationTime += LEASE_ENDDATE_THRESHOLD;
// delete old leases
if (m_StoreLeases)
{
for (auto it = m_Leases.begin (); it != m_Leases.end ();)
{
if (!(*it)->isUpdated)
{
(*it)->endDate = 0; // somebody might still hold it
m_Leases.erase (it++);
}
else
it++;
}
}
// verify
if (!m_Identity->Verify (m_Buffer, leases - m_Buffer, leases))
{
LogPrint (eLogWarning, "LeaseSet: verification failed");
m_IsValid = false;
}
}
const std::vector<std::shared_ptr<const Lease> > LeaseSet::GetNonExpiredLeases (bool withThreshold) const
{
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
std::vector<std::shared_ptr<const Lease> > leases;
for (auto it: m_Leases)
{
auto endDate = it->endDate;
if (withThreshold)
endDate += LEASE_ENDDATE_THRESHOLD;
else
endDate -= LEASE_ENDDATE_THRESHOLD;
if (ts < endDate)
leases.push_back (it);
}
return leases;
}
bool LeaseSet::HasExpiredLeases () const
{
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
for (auto it: m_Leases)
if (ts >= it->endDate) return true;
return false;
}
bool LeaseSet::IsExpired () const
{
if (IsEmpty ()) return true;
auto ts = i2p::util::GetMillisecondsSinceEpoch ();
return ts > m_ExpirationTime;
}
}
}