proxy: imp code

proxy/lookup.go

@@ -18,19 +18,6 @@ type lookupResult struct {
 	err  error
 }
 
-// ansAddrs returns a slice of addresses collected from resp answers.  resp must
-// not be nil.
-func (lr *lookupResult) ansAddrs() (addrs []netip.Addr) {
-	for _, ans := range lr.resp.Answer {
-		a := proxyutil.IPFromRR(ans)
-		if a != (netip.Addr{}) {
-			addrs = append(addrs, a)
-		}
-	}
-
-	return addrs
-}
-
 // lookupIPAddr resolves the specified host IP addresses.
 func (p *Proxy) lookupIPAddr(host string, qtype uint16, ch chan *lookupResult) {
 	req := (&dns.Msg{}).SetQuestion(host, qtype)
@@ -74,23 +61,30 @@ func (p *Proxy) LookupNetIP(
 			continue
 		}
 
-		addrs = append(addrs, result.ansAddrs()...)
+		addrs = appendAnswers(addrs, result.resp.Answer)
 	}
 
 	if len(addrs) == 0 && len(errs) != 0 {
 		return addrs, errors.Join(errs...)
 	}
 
-	return p.sortAddrs(addrs), nil
-}
-
-// sortAddrs returns addrs sorted according to this proxy configuration.
-func (p *Proxy) sortAddrs(addrs []netip.Addr) (sorted []netip.Addr) {
 	if p.Config.PreferIPv6 {
 		slices.SortStableFunc(addrs, netutil.PreferIPv6)
 	} else {
 		slices.SortStableFunc(addrs, netutil.PreferIPv4)
 	}
 
+	return addrs, nil
+}
+
+// appendAnswers returns a slice of with addresses appended from the given ans.
+func appendAnswers(addrs []netip.Addr, ans []dns.RR) (appended []netip.Addr) {
+	for _, ansRR := range ans {
+		a := proxyutil.IPFromRR(ansRR)
+		if a != (netip.Addr{}) {
+			addrs = append(addrs, a)
+		}
+	}
+
 	return addrs
 }