fix: filter public ips (#97)

* fix: only return public ips in fallback iter

* fix: sanitize last to ensure we only return public ips

* docs: add coment about cached router

* Revert "fix: only return public ips in fallback iter"

This reverts commit bb2fd4c.

* docs: update changelog

---------

Co-authored-by: Daniel N <2color@users.noreply.github.com>

Author: 2color

CHANGELOG.md

@@ -15,13 +15,14 @@ The following emojis are used to highlight certain changes:
 
 ### Added
 
-
 ### Changed
 
 ### Removed
 
 ### Fixed
 
+- Fix a bug whereby, cached peers with private multiaddrs were returned in `/routing/v1/providers` responses, as they were not passing through `sanitizeRouter`.
+
 ### Security
 
 ## [v0.7.0]

server.go

@@ -246,7 +246,8 @@ func getCombinedRouting(endpoints []string, dht routing.Routing, cachedAddrBook
 	var dhtRouter router
 
 	if cachedAddrBook != nil {
-		dhtRouter = NewCachedRouter(sanitizeRouter{libp2pRouter{routing: dht}}, cachedAddrBook)
+		cachedRouter := NewCachedRouter(libp2pRouter{routing: dht}, cachedAddrBook)
+		dhtRouter = sanitizeRouter{cachedRouter}
 	} else {
 		dhtRouter = sanitizeRouter{libp2pRouter{routing: dht}}
 	}

server_cached_router.go

@@ -48,6 +48,7 @@ const (
 )
 
 // cachedRouter wraps a router with the cachedAddrBook to retrieve cached addresses for peers without multiaddrs in FindProviders
+// it will also dispatch a FindPeer when a provider has no multiaddrs using the cacheFallbackIter
 type cachedRouter struct {
 	router
 	cachedAddrBook *cachedAddrBook