From 7d67a2dde0d2547e19650f5c6fa33d54b3f8b14d Mon Sep 17 00:00:00 2001
From: Lee Clagett <code@leeclagett.com>
Date: Tue, 29 Dec 2020 19:58:53 -0500
Subject: Add aggressive restrictions to pre-handshake p2p buffer limit

---
 src/cryptonote_basic/connection_context.h               | 2 ++
 src/cryptonote_protocol/cryptonote_protocol_handler.inl | 1 +
 src/cryptonote_protocol/levin_notify.cpp                | 2 +-
 src/p2p/net_node.h                                      | 3 +++
 4 files changed, 7 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/cryptonote_basic/connection_context.h b/src/cryptonote_basic/connection_context.h
index 9e012f8f5..e5c00d4f3 100644
--- a/src/cryptonote_basic/connection_context.h
+++ b/src/cryptonote_basic/connection_context.h
@@ -55,6 +55,8 @@ namespace cryptonote
       state_normal
     };
 
+    bool handshake_complete() const noexcept { return m_state != state_before_handshake; }
+
     state m_state;
     std::vector<std::pair<crypto::hash, uint64_t>> m_needed_objects;
     std::unordered_set<crypto::hash> m_requested_objects;
diff --git a/src/cryptonote_protocol/cryptonote_protocol_handler.inl b/src/cryptonote_protocol/cryptonote_protocol_handler.inl
index c76e5628d..1a4c6d033 100644
--- a/src/cryptonote_protocol/cryptonote_protocol_handler.inl
+++ b/src/cryptonote_protocol/cryptonote_protocol_handler.inl
@@ -2634,6 +2634,7 @@ skip:
     std::vector<std::pair<epee::net_utils::zone, boost::uuids::uuid>> fullConnections, fluffyConnections;
     m_p2p->for_each_connection([this, &exclude_context, &fullConnections, &fluffyConnections](connection_context& context, nodetool::peerid_type peer_id, uint32_t support_flags)
     {
+      // peer_id also filters out connections before handshake
       if (peer_id && exclude_context.m_connection_id != context.m_connection_id && context.m_remote_address.get_zone() == epee::net_utils::zone::public_)
       {
         if(m_core.fluffy_blocks_enabled() && (support_flags & P2P_SUPPORT_FLAG_FLUFFY_BLOCKS))
diff --git a/src/cryptonote_protocol/levin_notify.cpp b/src/cryptonote_protocol/levin_notify.cpp
index 69df22a92..ab4eeeb82 100644
--- a/src/cryptonote_protocol/levin_notify.cpp
+++ b/src/cryptonote_protocol/levin_notify.cpp
@@ -442,7 +442,7 @@ namespace levin
         zone->p2p->foreach_connection([txs, now, &zone, &source, &in_duration, &out_duration, &next_flush] (detail::p2p_context& context)
         {
           // When i2p/tor, only fluff to outbound connections
-          if (source != context.m_connection_id && (zone->nzone == epee::net_utils::zone::public_ || !context.m_is_income))
+          if (context.handshake_complete() && source != context.m_connection_id && (zone->nzone == epee::net_utils::zone::public_ || !context.m_is_income))
           {
             if (context.fluff_txs.empty())
               context.flush_time = now + (context.m_is_income ? in_duration() : out_duration());
diff --git a/src/p2p/net_node.h b/src/p2p/net_node.h
index 9fba5d636..1f9fa46a4 100644
--- a/src/p2p/net_node.h
+++ b/src/p2p/net_node.h
@@ -118,6 +118,8 @@ namespace nodetool
         m_in_timedsync(false)
     {}
 
+    static constexpr int handshake_command() noexcept { return 1001; }
+
     std::vector<cryptonote::blobdata> fluff_txs;
     std::chrono::steady_clock::time_point flush_time;
     peerid_type peer_id;
@@ -139,6 +141,7 @@ namespace nodetool
 
     typedef COMMAND_HANDSHAKE_T<typename t_payload_net_handler::payload_type> COMMAND_HANDSHAKE;
     typedef COMMAND_TIMED_SYNC_T<typename t_payload_net_handler::payload_type> COMMAND_TIMED_SYNC;
+    static_assert(p2p_connection_context::handshake_command() == COMMAND_HANDSHAKE::ID, "invalid handshake command id");
 
     typedef epee::net_utils::boosted_tcp_server<epee::levin::async_protocol_handler<p2p_connection_context>> net_server;
 
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