bool Beacon::StartActiveSession(const IpAddr &remoteAddr, const IpAddr &localAddr)
{
Session *session = NULL;
LogAssert(m_scheduler->IsMainThread());
session = findInSourceMap(remoteAddr, localAddr);
if (session)
{
if (session->IsActiveSession())
return true;
if (!session->UpgradeToActiveSession())
{
LogOptional(Log::Session, "Failed to upgrade Session id=%u for %s to %s is to an active session.",
session->GetId(),
localAddr.ToString(),
remoteAddr.ToString()
);
return false;
}
LogOptional(Log::Session, "Session id=%u for %s to %s is now an active session.",
session->GetId(),
localAddr.ToString(),
remoteAddr.ToString()
);
return true;
}
else
{
session = addSession(remoteAddr, localAddr);
if (!session)
return false;
LogOptional(Log::Session, "Manually added new session for %s to %s id=%u.",
localAddr.ToString(),
remoteAddr.ToString(),
session->GetId());
if (!session->StartActiveSession(remoteAddr, localAddr))
{
LogOptional(Log::Session, "Failed to start active session id=%u for %s to %s.",
session->GetId(),
localAddr.ToString(),
remoteAddr.ToString()
);
return false;
}
LogOptional(Log::Session, "Session id=%u for %s to %s is started as an active session.",
session->GetId(),
localAddr.ToString(),
remoteAddr.ToString()
);
return true;
}
}
void Beacon::handleListenSocket(Socket &socket)
{
SockAddr sourceAddr;
IpAddr destIpAddr, sourceIpAddr;
uint8_t ttl;
BfdPacket packet;
bool found;
Session *session = NULL;
if (!m_packet.DoRecvMsg(socket))
{
gLog.ErrnoError(m_packet.GetLastError(), "Error receiving on BFD listen socket");
return;
}
sourceAddr = m_packet.GetSrcAddress();
if (!LogVerify(sourceAddr.IsValid()))
return;
sourceIpAddr = IpAddr(sourceAddr);
destIpAddr = m_packet.GetDestAddress();
if (!destIpAddr.IsValid())
{
gLog.LogError("Could not get destination address for packet from %s.", sourceAddr.ToString());
return;
}
ttl = m_packet.GetTTLorHops(&found);
if (!found)
{
gLog.LogError("Could not get ttl for packet from %s.", sourceAddr.ToString());
return;
}
LogOptional(Log::Packet, "Received bfd packet %zu bytes from %s to %s", m_packet.GetDataSize(), sourceAddr.ToString(), destIpAddr.ToString());
//
// Check ip specific stuff. See draft-ietf-bfd-v4v6-1hop-11.txt
//
// Port
if (m_strictPorts)
{
if (sourceAddr.Port() < bfd::MinSourcePort) // max port is max value, so no need to check
{
LogOptional(Log::Discard, "Discard packet: bad source port %s to %s", sourceAddr.ToString(), destIpAddr.ToString());
return;
}
}
// TTL assumes that all control packets are from neighbors.
if (ttl != 255)
{
gLog.Optional(Log::Discard, "Discard packet: bad ttl/hops %hhu", ttl);
return;
}
if (!Session::InitialProcessControlPacket(m_packet.GetData(), m_packet.GetDataSize(), packet))
{
gLog.Optional(Log::Discard, "Discard packet");
return;
}
// We have a (partially) valid packet ... now find the correct session.
if (packet.header.yourDisc != 0)
{
DiscMapIt found = m_discMap.find(packet.header.yourDisc);
if (found == m_discMap.end())
{
if (gLog.LogTypeEnabled(Log::DiscardDetail))
Session::LogPacketContents(packet, false, true, sourceAddr, destIpAddr);
gLog.Optional(Log::Discard, "Discard packet: no session found for yourDisc <%u>.", packet.header.yourDisc);
return;
}
session = found->second;
if (session->GetRemoteAddress() != sourceIpAddr)
{
if (gLog.LogTypeEnabled(Log::DiscardDetail))
Session::LogPacketContents(packet, false, true, sourceAddr, destIpAddr);
LogOptional(Log::Discard, "Discard packet: mismatched yourDisc <%u> and ip <from %s to %s>.", packet.header.yourDisc, sourceAddr.ToString(), destIpAddr.ToString());
return;
}
}
else
{
// No discriminator
session = findInSourceMap(sourceIpAddr, destIpAddr);
if (NULL == session)
{
// No session yet .. create one !?
if (!m_allowAnyPassiveIP && m_allowedPassiveIP.find(sourceIpAddr) == m_allowedPassiveIP.end())
{
if (gLog.LogTypeEnabled(Log::DiscardDetail))
Session::LogPacketContents(packet, false, true, sourceAddr, destIpAddr);
LogOptional(Log::Discard, "Ignoring unauthorized bfd packets from %s", sourceAddr.ToString());
return;
}
session = addSession(sourceIpAddr, destIpAddr);
if (!session)
return;
if (!session->StartPassiveSession(sourceAddr, destIpAddr))
{
gLog.LogError("Failed to add new session for local %s to remote %s id=%d.", destIpAddr.ToString(), sourceAddr.ToString(), session->GetId());
KillSession(session);
}
LogOptional(Log::Session, "Added new session for local %s to remote %s id=%d.", destIpAddr.ToString(), sourceAddr.ToString(), session->GetId());
}
}
//
// We have a session that can handle the rest.
//
session->ProcessControlPacket(packet, sourceAddr.Port());
}