lokinet/llarp/exit/session.cpp

234 lines
6.8 KiB
C++

#include <exit/session.hpp>
#include <path/path.hpp>
#include <router/router.hpp>
namespace llarp
{
namespace exit
{
BaseSession::BaseSession(const llarp::RouterID& router,
std::function< bool(llarp_buffer_t) > writepkt,
llarp::Router* r, size_t numpaths, size_t hoplen)
: llarp::path::Builder(r, r->dht, numpaths, hoplen)
, m_ExitRouter(router)
, m_WritePacket(writepkt)
, m_Counter(0)
, m_LastUse(0)
{
r->crypto.identity_keygen(m_ExitIdentity);
}
BaseSession::~BaseSession()
{
}
bool
BaseSession::LoadIdentityFromFile(const char* fname)
{
return m_ExitIdentity.LoadFromFile(fname);
}
bool
BaseSession::ShouldBuildMore(llarp_time_t now) const
{
const size_t expect = (1 + (m_NumPaths / 2));
// check 30 seconds into the future and see if we need more paths
const llarp_time_t future = now + (30 * 1000);
if(NumPathsExistingAt(future) < expect)
return llarp::randint() % 4
== 0; // 25% chance for build if we will run out soon
// if we don't have the expended number of paths right now try building
// some if the cooldown timer isn't hit
if(AvailablePaths(llarp::path::ePathRoleExit) < expect)
return !path::Builder::BuildCooldownHit(now);
// maintain regular number of paths
return path::Builder::ShouldBuildMore(now);
}
bool
BaseSession::SelectHop(llarp_nodedb* db, const RouterContact& prev,
RouterContact& cur, size_t hop,
llarp::path::PathRole roles)
{
if(hop == numHops - 1)
{
return db->Get(m_ExitRouter, cur);
}
else
return path::Builder::SelectHop(db, prev, cur, hop, roles);
}
void
BaseSession::HandlePathBuilt(llarp::path::Path* p)
{
path::Builder::HandlePathBuilt(p);
p->SetDropHandler(std::bind(&BaseSession::HandleTrafficDrop, this,
std::placeholders::_1, std::placeholders::_2,
std::placeholders::_3));
p->SetExitTrafficHandler(
std::bind(&BaseSession::HandleTraffic, this, std::placeholders::_1,
std::placeholders::_2, std::placeholders::_3));
p->AddObtainExitHandler(std::bind(&BaseSession::HandleGotExit, this,
std::placeholders::_1,
std::placeholders::_2));
llarp::routing::ObtainExitMessage obtain;
obtain.S = p->NextSeqNo();
obtain.T = llarp::randint();
PopulateRequest(obtain);
if(!obtain.Sign(&router->crypto, m_ExitIdentity))
{
llarp::LogError("Failed to sign exit request");
return;
}
if(p->SendExitRequest(&obtain, router))
llarp::LogInfo("asking ", m_ExitRouter, " for exit");
else
llarp::LogError("faild to send exit request");
}
bool
BaseSession::HandleGotExit(llarp::path::Path* p, llarp_time_t b)
{
m_LastUse = router->Now();
if(b == 0)
llarp::LogInfo("obtained an exit via ", p->Endpoint());
return true;
}
bool
BaseSession::Stop()
{
auto sendExitClose = [&](llarp::path::Path* p) {
if(p->SupportsAnyRoles(llarp::path::ePathRoleExit))
{
llarp::LogInfo(p->Name(), " closing exit path");
llarp::routing::CloseExitMessage msg;
if(!(msg.Sign(&router->crypto, m_ExitIdentity)
&& p->SendExitClose(&msg, router)))
llarp::LogWarn(p->Name(), " failed to send exit close message");
}
};
ForEachPath(sendExitClose);
return llarp::path::Builder::Stop();
}
bool
BaseSession::HandleTraffic(llarp::path::Path* p, llarp_buffer_t buf,
uint64_t counter)
{
(void)p;
if(m_WritePacket)
{
llarp::net::IPv4Packet pkt;
if(!pkt.Load(buf))
return false;
m_Downstream.emplace(counter, pkt);
m_LastUse = router->Now();
return true;
}
return false;
}
bool
BaseSession::HandleTrafficDrop(llarp::path::Path* p, const PathID_t& path,
uint64_t s)
{
(void)p;
llarp::LogError("dropped traffic on exit ", m_ExitRouter, " S=", s,
" P=", path);
return true;
}
bool
BaseSession::QueueUpstreamTraffic(llarp::net::IPv4Packet pkt,
const size_t N)
{
auto buf = pkt.Buffer();
auto& queue = m_Upstream[buf.sz / N];
// queue overflow
if(queue.size() >= MaxUpstreamQueueLength)
return false;
if(queue.size() == 0)
{
queue.emplace_back();
return queue.back().PutBuffer(buf, m_Counter++);
}
auto& back = queue.back();
// pack to nearest N
if(back.Size() + buf.sz > N)
{
queue.emplace_back();
return queue.back().PutBuffer(buf, m_Counter++);
}
else
return back.PutBuffer(buf, m_Counter++);
}
bool
BaseSession::IsReady() const
{
return AvailablePaths(llarp::path::ePathRoleExit) > 0;
}
bool
BaseSession::IsExpired(llarp_time_t now) const
{
return m_LastUse && now > m_LastUse && now - m_LastUse > LifeSpan;
}
bool
BaseSession::Flush()
{
auto now = router->Now();
auto path = PickRandomEstablishedPath(llarp::path::ePathRoleExit);
if(path)
{
for(auto& item : m_Upstream)
{
auto& queue = item.second;
while(queue.size())
{
auto& msg = queue.front();
msg.S = path->NextSeqNo();
if(path->SendRoutingMessage(&msg, router))
m_LastUse = now;
queue.pop_front();
}
}
}
else
{
if(m_Upstream.size())
llarp::LogWarn("no path for exit session");
// discard upstream
for(auto& item : m_Upstream)
item.second.clear();
m_Upstream.clear();
}
while(m_Downstream.size())
{
if(m_WritePacket)
m_WritePacket(m_Downstream.top().second.ConstBuffer());
m_Downstream.pop();
}
return true;
}
SNodeSession::SNodeSession(const llarp::RouterID& snodeRouter,
std::function< bool(llarp_buffer_t) > writepkt,
llarp::Router* r, size_t numpaths, size_t hoplen,
bool useRouterSNodeKey)
: BaseSession(snodeRouter, writepkt, r, numpaths, hoplen)
{
if(useRouterSNodeKey)
{
m_ExitIdentity = r->identity;
}
}
} // namespace exit
} // namespace llarp