Add NetworkBehaviour::inject_new_external_addr (#1063)

core/src/swarm/behaviour.rs

@@ -89,6 +89,10 @@ pub trait NetworkBehaviour {
     fn inject_expired_listen_addr(&mut self, _addr: &Multiaddr) {
     }
 
+    /// Indicates to the behaviour that we have discovered a new external address for us.
+    fn inject_new_external_addr(&mut self, _addr: &Multiaddr) {
+    }
+
     /// Polls for things that swarm should do.
     ///
     /// This API mimics the API of the `Stream` trait.

core/src/swarm/swarm.rs

@@ -325,6 +325,7 @@ where TBehaviour: NetworkBehaviour<ProtocolsHandler = THandler>,
                 Async::Ready(NetworkBehaviourAction::ReportObservedAddr { address }) => {
                     for addr in self.raw_swarm.nat_traversal(&address) {
                         if self.external_addrs.iter().all(|a| *a != addr) {
+                            self.behaviour.inject_new_external_addr(&addr);
                             self.external_addrs.push(addr);
                         }
                     }

core/src/swarm/toggle.rs

@@ -115,7 +115,12 @@ where
         if let Some(inner) = self.inner.as_mut() {
             inner.inject_expired_listen_addr(addr)
         }
+    }
 
+    fn inject_new_external_addr(&mut self, addr: &Multiaddr) {
+        if let Some(inner) = self.inner.as_mut() {
+            inner.inject_new_external_addr(addr)
+        }
     }
 
     fn poll(&mut self, params: &mut PollParameters<'_>)

misc/core-derive/src/lib.rs

@@ -270,6 +270,20 @@ fn build_struct(ast: &DeriveInput, data_struct: &DataStruct) -> TokenStream {
         })
     };
 
+    // Build the list of statements to put in the body of `inject_new_external_addr()`.
+    let inject_new_external_addr_stmts = {
+        data_struct.fields.iter().enumerate().filter_map(move |(field_n, field)| {
+            if is_ignored(&field) {
+                return None;
+            }
+
+            Some(match field.ident {
+                Some(ref i) => quote!{ self.#i.inject_new_external_addr(addr); },
+                None => quote!{ self.#field_n.inject_new_external_addr(addr); },
+            })
+        })
+    };
+
     // Build the list of variants to put in the body of `inject_node_event()`.
     //
     // The event type is a construction of nested `#either_ident`s of the events of the children.
@@ -449,6 +463,10 @@ fn build_struct(ast: &DeriveInput, data_struct: &DataStruct) -> TokenStream {
                 #(#inject_expired_listen_addr_stmts);*
             }
 
+            fn inject_new_external_addr(&mut self, addr: &#multiaddr) {
+                #(#inject_new_external_addr_stmts);*
+            }
+
             fn inject_node_event(
                 &mut self,
                 peer_id: #peer_id,