From 0abb3e89fa6298041faa7e46d437e5a81f71cdd3 Mon Sep 17 00:00:00 2001 From: red-001 Date: Mon, 2 Nov 2020 21:21:03 +0000 Subject: [PATCH] Block attempts to connect to the client (#10589) A Minetest peer initiates a connection by sending a packet with an invalid peer_id, for whatever reason the code for doing this ran on both the client and the server meaning you could connect to a client if you knew what the address:port tuple it was listening on. --- src/network/connection.cpp | 2 +- src/network/connection.h | 5 +++++ src/network/connectionthreads.cpp | 5 ++++- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/src/network/connection.cpp b/src/network/connection.cpp index 1875d1461..0ba8c36b2 100644 --- a/src/network/connection.cpp +++ b/src/network/connection.cpp @@ -1566,7 +1566,7 @@ void Connection::sendAck(session_t peer_id, u8 channelnum, u16 seqnum) UDPPeer* Connection::createServerPeer(Address& address) { - if (getPeerNoEx(PEER_ID_SERVER) != 0) + if (ConnectedToServer()) { throw ConnectionException("Already connected to a server"); } diff --git a/src/network/connection.h b/src/network/connection.h index 2dc6d4397..24cd4fe4a 100644 --- a/src/network/connection.h +++ b/src/network/connection.h @@ -809,6 +809,11 @@ protected: void putEvent(ConnectionEvent &e); void TriggerSend(); + + bool ConnectedToServer() + { + return getPeerNoEx(PEER_ID_SERVER) != nullptr; + } private: MutexedQueue m_event_queue; diff --git a/src/network/connectionthreads.cpp b/src/network/connectionthreads.cpp index 28ed798d9..7b62bc792 100644 --- a/src/network/connectionthreads.cpp +++ b/src/network/connectionthreads.cpp @@ -956,8 +956,11 @@ void ConnectionReceiveThread::receive(SharedBuffer &packetdata, // command was sent reliably. } - /* The peer was not found in our lists. Add it. */ if (peer_id == PEER_ID_INEXISTENT) { + /* Ignore it if we are a client */ + if (m_connection->ConnectedToServer()) + return; + /* The peer was not found in our lists. Add it. */ peer_id = m_connection->createPeer(sender, MTP_MINETEST_RELIABLE_UDP, 0); }