Track inventory annoucements of transactions

A user may want to know if they are receiving an absurd amount of
transaction for DoS protection. They may also want to gauge the
connected-ness of a peer and disconnect if they decide the peer is
insufficiently connected.

Author: rustaceanrob

src/lib.rs

@@ -181,8 +181,10 @@ pub enum TimedMessage {
     CFilters,
     /// Bitcoin blocks
     Block,
-    /// Potential peers on the network
+    /// Potential peers on the network, either `addr` or `addrv2`.
     Addr,
+    /// Transaction announcements by `Tx`, `WTx`, or `WitnessTransaction`.
+    TransactionAnnouncement,
 }
 
 #[derive(Debug, Clone)]
@@ -196,6 +198,7 @@ impl TimedMessages {
             TimedMessage::CFilters,
             TimedMessage::Block,
             TimedMessage::Addr,
+            TimedMessage::TransactionAnnouncement,
         ] {
             map.insert(key, MessageRate::new());
         }

src/net.rs

@@ -16,6 +16,7 @@ use bitcoin::{
 };
 use p2p::{
     message::{NetworkMessage, RawNetworkMessage, V1MessageHeader},
+    message_blockdata::Inventory,
     Magic, NetworkExt,
 };
 
@@ -336,6 +337,26 @@ impl ConnectionReader {
                         }
                     }
                 }
+                NetworkMessage::Inv(payload) => {
+                    let payload = &payload.0;
+                    let now = Instant::now();
+                    if let Ok(mut lock) = self.timed_messages.lock() {
+                        for inv in payload {
+                            match inv {
+                                Inventory::WTx(_) => {
+                                    lock.add_single(TimedMessage::TransactionAnnouncement, now);
+                                }
+                                Inventory::Transaction(_) => {
+                                    lock.add_single(TimedMessage::TransactionAnnouncement, now);
+                                }
+                                Inventory::WitnessTransaction(_) => {
+                                    lock.add_single(TimedMessage::TransactionAnnouncement, now);
+                                }
+                                _ => (),
+                            }
+                        }
+                    }
+                }
                 _ => (),
             }
         }