3 files changed, 33 insertions, 2 deletions

diff --git a/src/transport/mod.rs b/src/transport/mod.rs
index 35e1e5f..a1fb9d5 100644
--- a/src/transport/mod.rs
+++ b/src/transport/mod.rs
@@ -252,6 +252,19 @@ pub(crate) enum ParsedMessage {
     NeighbourReply(NeighbourAnswer),
     /// Tells the recipient we are neighbours no more (`swarm::hyparview`).
     Disconnect(NeighbourAnswer),
+    /// Signatures of changes, sent on their own (`swarm::signatures`).
+    Signatures(SignaturesMessage),
+}
+
+/// SIGNATURES: signatures of changes no sync message took (`swarm::signatures`).
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub(crate) struct SignaturesMessage {
+    #[serde(with = "crate::transport::wire::codec::epoch")]
+    pub(crate) epoch: Epoch,
+    /// See `SyncEnvelope::epoch_seq`.
+    pub(crate) epoch_seq: u32,
+    /// As `SyncEnvelope::signatures`.
+    pub(crate) signatures: serde_bytes::ByteBuf,
 }
 
 /// A node's proof that it holds the key of its node ID (`identity`), sending from its
@@ -399,6 +412,7 @@ pub(crate) enum MessageKind {
     Neighbour,
     NeighbourReply,
     Disconnect,
+    Signatures,
 }
 
 impl ParsedMessage {
@@ -421,6 +435,7 @@ impl ParsedMessage {
             ParsedMessage::Neighbour(_) => MessageKind::Neighbour,
             ParsedMessage::NeighbourReply(_) => MessageKind::NeighbourReply,
             ParsedMessage::Disconnect(_) => MessageKind::Disconnect,
+            ParsedMessage::Signatures(_) => MessageKind::Signatures,
         }
     }
 
@@ -446,6 +461,7 @@ impl ParsedMessage {
             ParsedMessage::NeighbourReply(answer) | ParsedMessage::Disconnect(answer) => {
                 Some((answer.epoch, answer.epoch_seq))
             }
+            ParsedMessage::Signatures(message) => Some((message.epoch, message.epoch_seq)),
             ParsedMessage::Who(_)
             | ParsedMessage::Me(_)
             | ParsedMessage::Ping(_)
diff --git a/src/transport/traffic.rs b/src/transport/traffic.rs
index 13ca9fa..180d3b5 100644
--- a/src/transport/traffic.rs
+++ b/src/transport/traffic.rs
@@ -57,6 +57,8 @@ pub(crate) struct ByKind {
     pub(crate) plumtree: Counter,
     /// NEIGHBOUR, NEIGHBOUR_REPLY and DISCONNECT (`swarm::hyparview`).
     pub(crate) hyparview: Counter,
+    /// SIGNATURES (`swarm::signatures`).
+    pub(crate) signatures: Counter,
 }
 
 impl ByKind {
@@ -73,6 +75,7 @@ impl ByKind {
             MessageKind::Probe,
             MessageKind::Prune,
             MessageKind::Neighbour,
+            MessageKind::Signatures,
         ] {
             let theirs = *other.get(kind);
             self.get_mut(kind).absorb(theirs);
@@ -94,6 +97,7 @@ impl ByKind {
             MessageKind::Neighbour | MessageKind::NeighbourReply | MessageKind::Disconnect => {
                 &self.hyparview
             }
+            MessageKind::Signatures => &self.signatures,
         }
     }
 
@@ -112,6 +116,7 @@ impl ByKind {
             MessageKind::Neighbour | MessageKind::NeighbourReply | MessageKind::Disconnect => {
                 &mut self.hyparview
             }
+            MessageKind::Signatures => &mut self.signatures,
         }
     }
 }
@@ -321,6 +326,7 @@ fn names(kind: MessageKind) -> (&'static str, &'static str) {
         MessageKind::Neighbour => ("NEIGHBOUR", "hyparview"),
         MessageKind::NeighbourReply => ("NEIGHBOUR_REPLY", "hyparview"),
         MessageKind::Disconnect => ("DISCONNECT", "hyparview"),
+        MessageKind::Signatures => ("SIGNATURES", "signatures"),
     }
 }
 
diff --git a/src/transport/wire.rs b/src/transport/wire.rs
index 97f8819..88b2916 100644
--- a/src/transport/wire.rs
+++ b/src/transport/wire.rs
@@ -14,7 +14,7 @@ use super::{EncodedMessage, MessageKind, ParsedMessage};
 
 /// The wire format's version, the first byte of every payload. Bump it with every change
 /// to a message type or a codec (`golden_bytes` fails then).
-pub(crate) const VERSION: u8 = 40;
+pub(crate) const VERSION: u8 = 41;
 
 /// What the second byte of a payload says.
 fn tag(kind: MessageKind) -> u8 {
@@ -36,6 +36,7 @@ fn tag(kind: MessageKind) -> u8 {
         MessageKind::Neighbour => 16,
         MessageKind::NeighbourReply => 17,
         MessageKind::Disconnect => 18,
+        MessageKind::Signatures => 19,
     }
 }
 
@@ -97,6 +98,7 @@ pub(crate) fn encode(message: &ParsedMessage) -> Result<Vec<u8>, WireError> {
         ParsedMessage::NeighbourReply(answer) | ParsedMessage::Disconnect(answer) => {
             rmp_serde::encode::write(&mut payload, answer)?
         }
+        ParsedMessage::Signatures(message) => rmp_serde::encode::write(&mut payload, message)?,
     }
     Ok(payload)
 }
@@ -176,6 +178,8 @@ pub(crate) fn decode(payload: &[u8]) -> Result<ParsedMessage, WireError> {
         ParsedMessage::NeighbourReply(rmp_serde::from_slice(body)?)
     } else if is(MessageKind::Disconnect) {
         ParsedMessage::Disconnect(rmp_serde::from_slice(body)?)
+    } else if is(MessageKind::Signatures) {
+        ParsedMessage::Signatures(rmp_serde::from_slice(body)?)
     } else {
         return Err(WireError::UnknownKind(kind));
     })
@@ -535,6 +539,11 @@ pub(crate) fn samples() -> Vec<ParsedMessage> {
             epoch_seq: 1,
             agreed: false,
         }),
+        ParsedMessage::Signatures(crate::transport::SignaturesMessage {
+            epoch,
+            epoch_seq: 1,
+            signatures: serde_bytes::ByteBuf::from(vec![9; 96]),
+        }),
     ]
 }
 
@@ -566,7 +575,7 @@ mod tests {
     #[test]
     fn every_kind_round_trips() {
         let samples = samples();
-        assert_eq!(samples.len(), 17, "a kind is missing from `samples`");
+        assert_eq!(samples.len(), 18, "a kind is missing from `samples`");
         for message in samples {
             let bytes = encode(&message).unwrap();
             let decoded = decode(&bytes).unwrap();