indirect probes

1 files changed, 40 insertions, 0 deletions

diff --git a/src/transport/mod.rs b/src/transport/mod.rs
index 00e07e5..743e713 100644
--- a/src/transport/mod.rs
+++ b/src/transport/mod.rs
@@ -243,6 +243,10 @@ pub(crate) enum ParsedMessage {
     Links(LinksRequest),
     /// Answers a LINKS.
     LinksReply(LinksReply),
+    /// Asks whether the recipient reaches a member (`swarm::working_links`).
+    Probe(ProbeRequest),
+    /// Answers a PROBE.
+    ProbeReply(ProbeReply),
 }
 
 /// A node's proof that it holds the key of its node ID (`identity`), sending from its
@@ -385,6 +389,8 @@ pub(crate) enum MessageKind {
     Pong,
     Links,
     LinksReply,
+    Probe,
+    ProbeReply,
 }
 
 impl ParsedMessage {
@@ -402,6 +408,8 @@ impl ParsedMessage {
             ParsedMessage::Pong { .. } => MessageKind::Pong,
             ParsedMessage::Links(_) => MessageKind::Links,
             ParsedMessage::LinksReply(_) => MessageKind::LinksReply,
+            ParsedMessage::Probe(_) => MessageKind::Probe,
+            ParsedMessage::ProbeReply(_) => MessageKind::ProbeReply,
         }
     }
 
@@ -420,6 +428,8 @@ impl ParsedMessage {
             ParsedMessage::Blob(blob) => Some((blob.epoch, blob.epoch_seq)),
             ParsedMessage::Links(request) => Some((request.epoch, request.epoch_seq)),
             ParsedMessage::LinksReply(reply) => Some((reply.epoch, reply.epoch_seq)),
+            ParsedMessage::Probe(request) => Some((request.epoch, request.epoch_seq)),
+            ParsedMessage::ProbeReply(reply) => Some((reply.epoch, reply.epoch_seq)),
             ParsedMessage::Who(_)
             | ParsedMessage::Me(_)
             | ParsedMessage::Ping(_)
@@ -428,6 +438,36 @@ impl ParsedMessage {
     }
 }
 
+/// PROBE: whether the recipient reaches `member` (`swarm::working_links`), as SWIM
+/// asks others before it suspects a member. Answered from what the recipient knows,
+/// without contacting the member.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub(crate) struct ProbeRequest {
+    #[serde(with = "crate::transport::wire::codec::epoch")]
+    pub(crate) epoch: Epoch,
+    /// See `SyncEnvelope::epoch_seq`.
+    pub(crate) epoch_seq: u32,
+    /// Repeated in the reply.
+    pub(crate) nonce: u64,
+    /// The member asked about (its node ID).
+    pub(crate) member: String,
+}
+
+/// PROBE_REPLY: whether the sender reaches the member asked about.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub(crate) struct ProbeReply {
+    #[serde(with = "crate::transport::wire::codec::epoch")]
+    pub(crate) epoch: Epoch,
+    /// See `SyncEnvelope::epoch_seq`.
+    pub(crate) epoch_seq: u32,
+    /// The request's.
+    pub(crate) nonce: u64,
+    pub(crate) member: String,
+    /// It does (an active session that answers); it doesn't (it holds the member
+    /// dormant, or its HELLOs went unanswered); None: it can't tell (no contact with it).
+    pub(crate) reached: Option<bool>,
+}
+
 /// LINKS: what a member is asked for a map of the swarm (`swarm::links`).
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub(crate) struct LinksRequest {