2.8 KiB
Hacking on i2pd
This document contains notes compiled from hacking on i2pd
prerequisites
This guide assumes:
- a decent understanding of c++
- basic understanding of how I2P works at i2np level and up
general structure
Notes on multithreading
-
every component runs in its own thread
-
each component (usually) has a public function
GetService()
which can be used to obtain theboost::asio::io_service
that it uses. -
when talking between components/threads, always use
GetService().post()
and be mindful of stack allocated memory.
NetDb
NetDb.h
The i2p::data::netdb
is a i2p::data::NetDb
instance processes and dispatches inbound i2np messages passed in from transports.
global singleton at i2p::data::netdb
as of 2.10.1
NetDbRequests.h
For Pending RouterInfo/LeaseSet lookup and store requests
ClientContext
ClientContext.h
i2p::client::ClientContext
spawns all destinations used by the I2P router including the shared local destination.
global singleton at i2p::client::context
as of 2.10.1
Daemon
File: Daemon.cpp
i2p::util::Daemon_Singleton_Private
subclasses implement the daemon start-up and tear-down, creates Http Webui and I2P control server.
Destinations
Destination.h
each destination runs in its own thread
i2p::client::LeaseSetDestination
Base for i2p::client::ClientDestination
i2p::client::ClientDestination
Destination capable of creating (tcp/i2p) streams and datagram sessions.
Streaming.h
i2p::stream::StreamingDestination
Does not implement any destination related members, the name is a bit misleading.
Owns a i2p::client::ClientDestination
and runs in the destination thread.
Anyone creating or using streams outside of the destination thread MUST be aware of the consequences of multithreaded c++ :^)
If you use streaming please consider running all code within the destination thread using ClientDestination::GetService().post()
Garlic.h
Provides Inter-Destination routing primitives.
i2p:🧄:GarlicDestination
sublcass of i2p::client::LeaseSetDestination
for sending messages down shared routing paths.
i2p:🧄:GarlicRoutingSession
a point to point conversation between us and 1 other destination.
i2p:🧄:GarlicRoutingPath
A routing path currently used by a routing session. specifies which outbound tunnel to use and which remote lease set to use for OBEP
to IBGW
inter tunnel communication.
members:
- outboundTunnel (OBEP)
- remoteLease (IBGW)
- rtt (round trip time)
- updatedTime (last time this path's IBGW/OBEP was updated)
- numTimesUsesd (number of times this path was used)
Transports
each transport runs in its own thread
Transports.h
i2p::transport::Transports
contains NTCP and SSU transport instances