From 608b0eb08eddac3de2f027f8dd203306b7699147 Mon Sep 17 00:00:00 2001
From: OlivierHecart <olivier.hecart@adlinktech.com>
Date: Fri, 13 Dec 2024 10:43:18 +0100
Subject: [PATCH] Add gossip target option for p2p peers

---
 commons/zenoh-config/src/defaults.rs         |  9 +++++++
 commons/zenoh-config/src/lib.rs              |  2 ++
 zenoh/src/net/routing/hat/p2p_peer/gossip.rs | 27 +++++++++++++++-----
 zenoh/src/net/routing/hat/p2p_peer/mod.rs    |  6 +++++
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/commons/zenoh-config/src/defaults.rs b/commons/zenoh-config/src/defaults.rs
index 195a08a07..eb000923e 100644
--- a/commons/zenoh-config/src/defaults.rs
+++ b/commons/zenoh-config/src/defaults.rs
@@ -95,6 +95,15 @@ pub mod scouting {
     pub mod gossip {
         pub const enabled: bool = true;
         pub const multihop: bool = false;
+        pub mod target {
+            pub const router: &crate::WhatAmIMatcher = // "router|peer"
+                &crate::WhatAmIMatcher::empty().router().peer();
+            pub const peer: &crate::WhatAmIMatcher = // "router|peer"
+                &crate::WhatAmIMatcher::empty().router().peer();
+            pub const client: &crate::WhatAmIMatcher = // ""
+                &crate::WhatAmIMatcher::empty();
+            mode_accessor!(crate::WhatAmIMatcher);
+        }
         pub mod autoconnect {
             pub const router: &crate::WhatAmIMatcher = // ""
                 &crate::WhatAmIMatcher::empty();
diff --git a/commons/zenoh-config/src/lib.rs b/commons/zenoh-config/src/lib.rs
index 30bd9a7c8..a00755c87 100644
--- a/commons/zenoh-config/src/lib.rs
+++ b/commons/zenoh-config/src/lib.rs
@@ -315,6 +315,8 @@ validated_struct::validator! {
                 /// It mostly makes sense when using "linkstate" routing mode where all nodes in the subsystem don't have
                 /// direct connectivity with each other.
                 multihop: Option<bool>,
+                /// Which type of Zenoh instances to send gossip messages to.
+                target: Option<ModeDependentValue<WhatAmIMatcher>>,
                 /// Which type of Zenoh instances to automatically establish sessions with upon discovery through gossip.
                 autoconnect: Option<ModeDependentValue<WhatAmIMatcher>>,
             },
diff --git a/zenoh/src/net/routing/hat/p2p_peer/gossip.rs b/zenoh/src/net/routing/hat/p2p_peer/gossip.rs
index b9155b44b..715ab0d1d 100644
--- a/zenoh/src/net/routing/hat/p2p_peer/gossip.rs
+++ b/zenoh/src/net/routing/hat/p2p_peer/gossip.rs
@@ -96,6 +96,7 @@ pub(super) struct Network {
     pub(super) router_peers_failover_brokering: bool,
     pub(super) gossip: bool,
     pub(super) gossip_multihop: bool,
+    pub(super) target: WhatAmIMatcher,
     pub(super) autoconnect: WhatAmIMatcher,
     pub(super) wait_declares: bool,
     pub(super) idx: NodeIndex,
@@ -113,6 +114,7 @@ impl Network {
         router_peers_failover_brokering: bool,
         gossip: bool,
         gossip_multihop: bool,
+        target: WhatAmIMatcher,
         autoconnect: WhatAmIMatcher,
         wait_declares: bool,
     ) -> Self {
@@ -130,6 +132,7 @@ impl Network {
             router_peers_failover_brokering,
             gossip,
             gossip_multihop,
+            target,
             autoconnect,
             wait_declares,
             idx,
@@ -231,13 +234,18 @@ impl Network {
     }
 
     fn send_on_link(&self, idxs: Vec<(NodeIndex, Details)>, transport: &TransportUnicast) {
-        if let Ok(msg) = self.make_msg(idxs) {
-            tracing::trace!("{} Send to {:?} {:?}", self.name, transport.get_zid(), msg);
-            if let Err(e) = transport.schedule(msg) {
-                tracing::debug!("{} Error sending LinkStateList: {}", self.name, e);
+        if transport
+            .get_whatami()
+            .is_ok_and(|w| self.target.matches(w))
+        {
+            if let Ok(msg) = self.make_msg(idxs) {
+                tracing::trace!("{} Send to {:?} {:?}", self.name, transport.get_zid(), msg);
+                if let Err(e) = transport.schedule(msg) {
+                    tracing::debug!("{} Error sending LinkStateList: {}", self.name, e);
+                }
+            } else {
+                tracing::error!("Failed to encode Linkstate message");
             }
-        } else {
-            tracing::error!("Failed to encode Linkstate message");
         }
     }
 
@@ -247,7 +255,12 @@ impl Network {
     {
         if let Ok(msg) = self.make_msg(idxs) {
             for link in self.links.values() {
-                if parameters(link) {
+                if link
+                    .transport
+                    .get_whatami()
+                    .is_ok_and(|w| self.target.matches(w))
+                    && parameters(link)
+                {
                     tracing::trace!("{} Send to {} {:?}", self.name, link.zid, msg);
                     if let Err(e) = link.transport.schedule(msg.clone()) {
                         tracing::debug!("{} Error sending LinkStateList: {}", self.name, e);
diff --git a/zenoh/src/net/routing/hat/p2p_peer/mod.rs b/zenoh/src/net/routing/hat/p2p_peer/mod.rs
index f50e57ba9..4b5d727b5 100644
--- a/zenoh/src/net/routing/hat/p2p_peer/mod.rs
+++ b/zenoh/src/net/routing/hat/p2p_peer/mod.rs
@@ -115,6 +115,11 @@ impl HatBaseTrait for HatCode {
         let whatami = tables.whatami;
         let gossip = unwrap_or_default!(config.scouting().gossip().enabled());
         let gossip_multihop = unwrap_or_default!(config.scouting().gossip().multihop());
+        let gossip_target = if gossip {
+            *unwrap_or_default!(config.scouting().gossip().target().get(whatami))
+        } else {
+            WhatAmIMatcher::empty()
+        };
         let autoconnect = if gossip {
             *unwrap_or_default!(config.scouting().gossip().autoconnect().get(whatami))
         } else {
@@ -133,6 +138,7 @@ impl HatBaseTrait for HatCode {
                 router_peers_failover_brokering,
                 gossip,
                 gossip_multihop,
+                gossip_target,
                 autoconnect,
                 wait_declares,
             ));