TurnManager.cxx

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#include <rutil/Lock.hxx>
 
#include "TurnManager.hxx"
#include "TurnAllocation.hxx"
#include <rutil/Logger.hxx>
#include "ReTurnSubsystem.hxx"
 
#define RESIPROCATE_SUBSYSTEM ReTurnSubsystem::RETURN
 
using namespace std;
 
namespace reTurn {
 
TurnManager::TurnManager(asio::io_context& ioService, const ReTurnConfig& config) : 
   mLastAllocatedUdpPort(config.mAllocationPortRangeMin-1),
   mLastAllocatedTcpPort(config.mAllocationPortRangeMin-1),
   mIOService(ioService),
   mConfig(config)
{
   // Initialize Allocation Ports
   for(unsigned short i = config.mAllocationPortRangeMin; i <= config.mAllocationPortRangeMax && i != 0; i++) // i != 0 catches case where we increment 65535 (as an unsigned short)
   {
      mUdpAllocationPorts[i] = PortStateUnallocated;
      mTcpAllocationPorts[i] = PortStateUnallocated;
   }
}
 
TurnManager::~TurnManager()
{
   InfoLog(<< "Turn Manager destroyed.");
}
 
bool
TurnManager::allocationQuotaReached(const resip::Data& username) const
{
   if(mConfig.mMaxAllocationsPerUser == 0)
   {
      return false;
   }
   std::map<resip::Data, unsigned long>::const_iterator it = mAllocationsPerUser.find(username);
   return it != mAllocationsPerUser.end() && it->second >= mConfig.mMaxAllocationsPerUser;
}
 
void
TurnManager::addAllocation(const resip::Data& username)
{
   ++mAllocationsPerUser[username];
}
 
void
TurnManager::removeAllocation(const resip::Data& username)
{
   std::map<resip::Data, unsigned long>::iterator it = mAllocationsPerUser.find(username);
   if(it != mAllocationsPerUser.end() && --it->second == 0)
   {
      mAllocationsPerUser.erase(it);
   }
}
 
bool
TurnManager::addConnection(const asio::ip::address& address)
{
   unsigned long& count = mConnectionsPerIp[address];
   if(mConfig.mMaxTcpConnectionsPerIp != 0 && count >= mConfig.mMaxTcpConnectionsPerIp)
   {
      // Logged once while the address is at the limit, as an attacker may keep trying
      if(mConnectionLimitLogged.insert(address).second)
      {
         WarningLog(<< "Already " << count << " TCP/TLS connections from " << address.to_string() << " (MaxTcpConnectionsPerIp), closing new ones");
      }
      else
      {
         DebugLog(<< "Already " << count << " TCP/TLS connections from " << address.to_string() << ", closing a new one");
      }
      return false;
   }
   ++count;
   return true;
}
 
void
TurnManager::removeConnection(const asio::ip::address& address)
{
   std::map<asio::ip::address, unsigned long>::iterator it = mConnectionsPerIp.find(address);
   if(it != mConnectionsPerIp.end())
   {
      if(--it->second < mConfig.mMaxTcpConnectionsPerIp)
      {
         mConnectionLimitLogged.erase(address);
      }
      if(it->second == 0)
      {
         mConnectionsPerIp.erase(it);
      }
   }
}
 
unsigned short 
TurnManager::allocateAnyPort(StunTuple::TransportType transport)
{
   PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
   unsigned short startPortToCheck = advanceLastAllocatedPort(transport);
   unsigned short portToCheck = startPortToCheck;
   while(portAllocationMap[portToCheck] != PortStateUnallocated)
   {
      portToCheck = advanceLastAllocatedPort(transport);
      if(portToCheck == startPortToCheck) return 0;  // If we checked all available ports and none found - then return 0
   }
   portAllocationMap[portToCheck] = PortStateAllocated;
   return portToCheck;
}
 
unsigned short 
TurnManager::allocateEvenPort(StunTuple::TransportType transport)
{
   PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
   unsigned short startPortToCheck = advanceLastAllocatedPort(transport);
   // Ensure start port is even
   while(startPortToCheck % 2 != 0)
   {
      startPortToCheck = advanceLastAllocatedPort(transport);
   }
   unsigned short portToCheck = startPortToCheck;
   while(portAllocationMap[portToCheck] != PortStateUnallocated)
   {
      portToCheck = advanceLastAllocatedPort(transport, 2);
      if(portToCheck == startPortToCheck) return 0;  // If we checked all available ports and none found - then return 0
   }
   portAllocationMap[portToCheck] = PortStateAllocated;
   return portToCheck;
}
 
// Note:  This is not used, since requesting an odd port was removed
unsigned short 
TurnManager::allocateOddPort(StunTuple::TransportType transport)
{
   PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
   unsigned short startPortToCheck = advanceLastAllocatedPort(transport);
   // Ensure start port is odd
   while(startPortToCheck % 2 != 1)
   {
      startPortToCheck = advanceLastAllocatedPort(transport);
   }
   unsigned short portToCheck = startPortToCheck;
   while(portAllocationMap[portToCheck] != PortStateUnallocated)
   {
      portToCheck = advanceLastAllocatedPort(transport, 2);
      if(portToCheck == startPortToCheck) return 0;  // If we checked all available ports and none found - then return 0
   }
   portAllocationMap[portToCheck] = PortStateAllocated;
   return portToCheck;
}
 
unsigned short 
TurnManager::allocateEvenPortPair(StunTuple::TransportType transport)
{
   PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
   unsigned short startPortToCheck = advanceLastAllocatedPort(transport);
   // Ensure start port is even and that start port + 1 is in range
   while(startPortToCheck % 2 != 0 ||
         startPortToCheck + 1 == 0 ||
         startPortToCheck + 1 > mConfig.mAllocationPortRangeMax )
   {
      startPortToCheck = advanceLastAllocatedPort(transport);
   }
   unsigned short portToCheck = startPortToCheck;
   while(portAllocationMap[portToCheck] != PortStateUnallocated || portAllocationMap[portToCheck+1] != PortStateUnallocated)
   {
      portToCheck = advanceLastAllocatedPort(transport, 2);
      if(portToCheck == startPortToCheck) return 0;  // If we checked all available ports and none found - then return 0
   }
   portAllocationMap[portToCheck] = PortStateAllocated;
   portAllocationMap[portToCheck+1] = PortStateReserved;
   return portToCheck;
}
 
bool 
TurnManager::allocatePort(StunTuple::TransportType transport, unsigned short port, bool reserved)
{
   if(port >= mConfig.mAllocationPortRangeMin && port <= mConfig.mAllocationPortRangeMax)
   {
      PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
      if(reserved)
      {
         if(portAllocationMap[port] == PortStateReserved)
         {
            portAllocationMap[port] = PortStateAllocated;
            return true;
         }
      }
      else
      {
         if(portAllocationMap[port] == PortStateUnallocated)  
         {
            portAllocationMap[port] = PortStateAllocated;
            return true;
         }
      }
   }
   return false;
}
 
void 
TurnManager::deallocatePort(StunTuple::TransportType transport, unsigned short port)
{
   if(port >= mConfig.mAllocationPortRangeMin && port <= mConfig.mAllocationPortRangeMax)
   {
      PortAllocationMap& portAllocationMap = getPortAllocationMap(transport);
      portAllocationMap[port] = PortStateUnallocated;
 
      // If port is even - check if next higher port is reserved - if so unallocate it
      if(port % 2 == 0 && portAllocationMap[port+1] == PortStateReserved)
      {
         portAllocationMap[port+1] = PortStateUnallocated;
      }
   }
}
 
TurnManager::PortAllocationMap& 
TurnManager::getPortAllocationMap(StunTuple::TransportType transport)
{
   switch(transport)
   {
   case StunTuple::TCP:
   case StunTuple::TLS:
      return mTcpAllocationPorts;
   case StunTuple::UDP:
   default:
      return mUdpAllocationPorts;
   }
}
 
unsigned short 
TurnManager::advanceLastAllocatedPort(StunTuple::TransportType transport, unsigned int numToAdvance)
{
   switch(transport)
   {
   case StunTuple::TCP:
   case StunTuple::TLS:
      mLastAllocatedTcpPort+=numToAdvance;
      if(mLastAllocatedTcpPort > mConfig.mAllocationPortRangeMax) 
      {
         mLastAllocatedTcpPort = mConfig.mAllocationPortRangeMin+(mLastAllocatedTcpPort-mConfig.mAllocationPortRangeMax-1);
      }
      else if(mLastAllocatedTcpPort == 0 /* Wrap around */)
      {
         mLastAllocatedTcpPort = mConfig.mAllocationPortRangeMin;
      }
      return mLastAllocatedTcpPort;
   case StunTuple::UDP:
   default:
      mLastAllocatedUdpPort+=numToAdvance;
      if(mLastAllocatedUdpPort > mConfig.mAllocationPortRangeMax) 
      {
         mLastAllocatedUdpPort = mConfig.mAllocationPortRangeMin+(mLastAllocatedUdpPort-mConfig.mAllocationPortRangeMax-1);
      }
      else if(mLastAllocatedUdpPort == 0 /* Wrap around */)
      {
         mLastAllocatedUdpPort = mConfig.mAllocationPortRangeMin;
      }
      return mLastAllocatedUdpPort;
   }
}
 
} // namespace
 
 
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