lokinet/llarp/iwp/linklayer.cpp
Jason Rhinelander 36792d4337
Fix multi-field < ordering
Lots and lots of places in the code had broken < operators because they
are returning something like:

    foo < other.foo or bar < other.bar;

but this breaks both the strict weak ordering requirements that are
required for the "Compare" requirement for things like
std::map/set/priority_queue.

For example:

    a = {.foo=1, .bar=3}
    b = {.foo=3, .bar=1}

does not have an ordering over a and b (both `a < b` and `b < a` are
satisfied at the same time).

This needs to be instead something like:

    foo < other.foo or (foo == other.foo and bar < other.bar)

but that's a bit clunkier, and it is easier to use std::tie for tuple's
built-in < comparison which does the right thing:

    std::tie(foo, bar) < std::tie(other.foo, other.bar)

(Initially I noticed this in SockAddr/sockaddr_in6, but upon further
investigation this extends to the major of multi-field `operator<`'s.)

This fixes it by using std::tie (or something similar) everywhere we are
doing multi-field inequalities.
2022-10-13 16:29:13 -03:00

116 lines
2.9 KiB
C++

#include "linklayer.hpp"
#include "session.hpp"
#include <llarp/config/key_manager.hpp>
#include <memory>
#include <unordered_set>
namespace llarp::iwp
{
LinkLayer::LinkLayer(
std::shared_ptr<KeyManager> keyManager,
std::shared_ptr<EventLoop> ev,
GetRCFunc getrc,
LinkMessageHandler h,
SignBufferFunc sign,
BeforeConnectFunc_t before,
SessionEstablishedHandler est,
SessionRenegotiateHandler reneg,
TimeoutHandler timeout,
SessionClosedHandler closed,
PumpDoneHandler pumpDone,
WorkerFunc_t worker,
bool allowInbound)
: ILinkLayer(
keyManager, getrc, h, sign, before, est, reneg, timeout, closed, pumpDone, worker)
, m_Wakeup{ev->make_waker([this]() { HandleWakeupPlaintext(); })}
, m_Inbound{allowInbound}
{}
std::string_view
LinkLayer::Name() const
{
return "iwp";
}
std::string
LinkLayer::PrintableName() const
{
if (m_Inbound)
return "inbound iwp link";
else
return "outbound iwp link";
}
uint16_t
LinkLayer::Rank() const
{
return 2;
}
void
LinkLayer::RecvFrom(const SockAddr& from, ILinkSession::Packet_t pkt)
{
std::shared_ptr<ILinkSession> session;
auto itr = m_AuthedAddrs.find(from);
bool isNewSession = false;
if (itr == m_AuthedAddrs.end())
{
Lock_t lock{m_PendingMutex};
auto it = m_Pending.find(from);
if (it == m_Pending.end())
{
if (not m_Inbound)
return;
isNewSession = true;
it = m_Pending.emplace(from, std::make_shared<Session>(this, from)).first;
}
session = it->second;
}
else
{
if (auto s_itr = m_AuthedLinks.find(itr->second); s_itr != m_AuthedLinks.end())
session = s_itr->second;
}
if (session)
{
bool success = session->Recv_LL(std::move(pkt));
if (not success and isNewSession)
{
LogDebug("Brand new session failed; removing from pending sessions list");
m_Pending.erase(from);
}
WakeupPlaintext();
}
}
std::shared_ptr<ILinkSession>
LinkLayer::NewOutboundSession(const RouterContact& rc, const AddressInfo& ai)
{
if (m_Inbound)
throw std::logic_error{"inbound link cannot make outbound sessions"};
return std::make_shared<Session>(this, rc, ai);
}
void
LinkLayer::WakeupPlaintext()
{
m_Wakeup->Trigger();
}
void
LinkLayer::HandleWakeupPlaintext()
{
// Copy bare pointers out first because HandlePlaintext can end up removing themselves from the
// structures.
m_WakingUp.clear(); // Reused to minimize allocations.
for (const auto& [router_id, session] : m_AuthedLinks)
m_WakingUp.push_back(session.get());
for (const auto& [addr, session] : m_Pending)
m_WakingUp.push_back(session.get());
for (auto* session : m_WakingUp)
session->HandlePlaintext();
PumpDone();
}
} // namespace llarp::iwp