lokinet/llarp/exit/session.cpp
2019-09-03 20:52:28 +01:00

358 lines
9.6 KiB
C++

#include <exit/session.hpp>
#include <crypto/crypto.hpp>
#include <nodedb.hpp>
#include <path/path_context.hpp>
#include <path/path.hpp>
#include <router/abstractrouter.hpp>
#include <util/meta/memfn.hpp>
#include <utility>
namespace llarp
{
namespace exit
{
BaseSession::BaseSession(
const llarp::RouterID& routerId,
std::function< bool(const llarp_buffer_t&) > writepkt,
AbstractRouter* r, size_t numpaths, size_t hoplen, bool bundleRC)
: llarp::path::Builder(r, numpaths, hoplen)
, m_ExitRouter(routerId)
, m_WritePacket(std::move(writepkt))
, m_Counter(0)
, m_LastUse(0)
, m_BundleRC(bundleRC)
{
CryptoManager::instance()->identity_keygen(m_ExitIdentity);
}
BaseSession::~BaseSession() = default;
void
BaseSession::HandlePathDied(path::Path_ptr p)
{
p->Rebuild();
}
util::StatusObject
BaseSession::ExtractStatus() const
{
auto obj = path::Builder::ExtractStatus();
obj["lastExitUse"] = m_LastUse;
auto pub = m_ExitIdentity.toPublic();
obj["exitIdentity"] = pub.ToString();
return obj;
}
bool
BaseSession::LoadIdentityFromFile(const char* fname)
{
return m_ExitIdentity.LoadFromFile(fname);
}
bool
BaseSession::ShouldBuildMore(llarp_time_t now) const
{
const size_t expect = (1 + (numPaths / 2));
// check 30 seconds into the future and see if we need more paths
const llarp_time_t future = now + (30 * 1000) + buildIntervalLimit;
return NumPathsExistingAt(future) < expect && !BuildCooldownHit(now);
}
void
BaseSession::BlacklistSnode(const RouterID snode)
{
m_SnodeBlacklist.insert(std::move(snode));
}
bool
BaseSession::SelectHop(llarp_nodedb* db, const std::set< RouterID >& prev,
RouterContact& cur, size_t hop,
llarp::path::PathRole roles)
{
std::set< RouterID > exclude = prev;
for(const auto& snode : m_SnodeBlacklist)
{
if(snode != m_ExitRouter)
exclude.insert(snode);
}
exclude.insert(m_ExitRouter);
if(hop == numHops - 1)
{
if(db->Get(m_ExitRouter, cur))
return true;
m_router->LookupRouter(m_ExitRouter, nullptr);
return false;
}
return path::Builder::SelectHop(db, exclude, cur, hop, roles);
}
bool
BaseSession::CheckPathDead(path::Path_ptr, llarp_time_t dlt)
{
return dlt >= 10000;
}
void
BaseSession::HandlePathBuilt(llarp::path::Path_ptr p)
{
path::Builder::HandlePathBuilt(p);
p->SetDropHandler(util::memFn(&BaseSession::HandleTrafficDrop, this));
p->SetDeadChecker(util::memFn(&BaseSession::CheckPathDead, this));
p->SetExitTrafficHandler(util::memFn(&BaseSession::HandleTraffic, this));
p->AddObtainExitHandler(util::memFn(&BaseSession::HandleGotExit, this));
routing::ObtainExitMessage obtain;
obtain.S = p->NextSeqNo();
obtain.T = llarp::randint();
PopulateRequest(obtain);
if(!obtain.Sign(m_ExitIdentity))
{
llarp::LogError("Failed to sign exit request");
return;
}
if(p->SendExitRequest(obtain, m_router))
llarp::LogInfo("asking ", m_ExitRouter, " for exit");
else
llarp::LogError("failed to send exit request");
}
void
BaseSession::AddReadyHook(SessionReadyFunc func)
{
m_PendingCallbacks.emplace_back(func);
}
bool
BaseSession::HandleGotExit(llarp::path::Path_ptr p, llarp_time_t b)
{
m_LastUse = m_router->Now();
if(b == 0)
{
llarp::LogInfo("obtained an exit via ", p->Endpoint());
CallPendingCallbacks(true);
}
return true;
}
void
BaseSession::CallPendingCallbacks(bool success)
{
if(success)
{
auto self = shared_from_this();
for(auto& f : m_PendingCallbacks)
f(self);
}
else
{
for(auto& f : m_PendingCallbacks)
f(nullptr);
}
m_PendingCallbacks.clear();
}
void
BaseSession::ResetInternalState()
{
auto sendExitClose = [&](const llarp::path::Path_ptr p) {
const static auto roles =
llarp::path::ePathRoleExit | llarp::path::ePathRoleSVC;
if(p->SupportsAnyRoles(roles))
{
llarp::LogInfo(p->Name(), " closing exit path");
routing::CloseExitMessage msg;
if(msg.Sign(m_ExitIdentity) && p->SendExitClose(msg, m_router))
{
p->ClearRoles(roles);
}
else
llarp::LogWarn(p->Name(), " failed to send exit close message");
}
};
ForEachPath(sendExitClose);
path::Builder::ResetInternalState();
}
bool
BaseSession::Stop()
{
CallPendingCallbacks(false);
auto sendExitClose = [&](const path::Path_ptr p) {
if(p->SupportsAnyRoles(path::ePathRoleExit))
{
LogInfo(p->Name(), " closing exit path");
routing::CloseExitMessage msg;
if(!(msg.Sign(m_ExitIdentity) && p->SendExitClose(msg, m_router)))
LogWarn(p->Name(), " failed to send exit close message");
}
};
ForEachPath(sendExitClose);
m_router->pathContext().RemovePathSet(shared_from_this());
return path::Builder::Stop();
}
bool
BaseSession::HandleTraffic(llarp::path::Path_ptr, const llarp_buffer_t& buf,
uint64_t counter)
{
if(m_WritePacket)
{
llarp::net::IPPacket pkt;
if(!pkt.Load(buf))
return false;
m_Downstream.emplace(counter, pkt);
m_LastUse = m_router->Now();
return true;
}
return false;
}
bool
BaseSession::HandleTrafficDrop(llarp::path::Path_ptr p,
const PathID_t& path, uint64_t s)
{
llarp::LogError("dropped traffic on exit ", m_ExitRouter, " S=", s,
" P=", path);
p->EnterState(path::ePathIgnore, m_router->Now());
return true;
}
bool
BaseSession::QueueUpstreamTraffic(llarp::net::IPPacket pkt, const size_t N)
{
const llarp_buffer_t& 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++);
}
return back.PutBuffer(buf, m_Counter++);
}
bool
BaseSession::IsReady() const
{
const size_t expect = (1 + (numPaths / 2));
return AvailablePaths(llarp::path::ePathRoleExit) >= expect;
}
bool
BaseSession::IsExpired(llarp_time_t now) const
{
return m_LastUse && now > m_LastUse && now - m_LastUse > LifeSpan;
}
bool
BaseSession::UrgentBuild(llarp_time_t now) const
{
if(!IsReady())
return NumInStatus(path::ePathBuilding) < numPaths;
return path::Builder::UrgentBuild(now);
}
bool
BaseSession::FlushUpstream()
{
auto now = m_router->Now();
auto path = PickRandomEstablishedPath(llarp::path::ePathRoleExit);
if(path)
{
for(auto& item : m_Upstream)
{
auto& queue = item.second; // XXX: uninitialised memory here!
while(queue.size())
{
auto& msg = queue.front();
if(path)
{
msg.S = path->NextSeqNo();
if(path->SendRoutingMessage(msg, m_router))
m_LastUse = now;
}
queue.pop_front();
// spread across all paths
path = PickRandomEstablishedPath(llarp::path::ePathRoleExit);
}
}
}
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();
if(numHops == 1)
{
auto r = m_router;
RouterContact rc;
if(r->nodedb()->Get(m_ExitRouter, rc))
r->TryConnectAsync(rc, 5);
else
r->LookupRouter(m_ExitRouter,
[r](const std::vector< RouterContact >& results) {
if(results.size())
r->TryConnectAsync(results[0], 5);
});
}
else if(UrgentBuild(now))
BuildOneAlignedTo(m_ExitRouter);
}
return true;
}
void
BaseSession::FlushDownstream()
{
while(m_Downstream.size())
{
if(m_WritePacket)
m_WritePacket(m_Downstream.top().second.ConstBuffer());
m_Downstream.pop();
}
}
SNodeSession::SNodeSession(
const llarp::RouterID& snodeRouter,
std::function< bool(const llarp_buffer_t&) > writepkt,
AbstractRouter* r, size_t numpaths, size_t hoplen,
bool useRouterSNodeKey, bool bundleRC)
: BaseSession(snodeRouter, writepkt, r, numpaths, hoplen, bundleRC)
{
if(useRouterSNodeKey)
{
m_ExitIdentity = r->identity();
}
}
std::string
SNodeSession::Name() const
{
return "SNode::" + m_ExitRouter.ToString();
}
std::string
ExitSession::Name() const
{
return "Exit::" + m_ExitRouter.ToString();
}
} // namespace exit
} // namespace llarp