From 81286e4b32baed09e6151ce4f8e763f449b81331 Mon Sep 17 00:00:00 2001
From: Andrew Gillis <gammazero@users.noreply.github.com>
Date: Tue, 9 May 2023 14:54:03 -0700
Subject: [PATCH] Ignore multiaddrs with unknown protocols (#30)

If new protocols, unknown to the indexer or assigner service, are encoded into multiaddrs in announce messages, then ignore these. This will allow older indexers to accept messages even when newer address types are included.

Fixes issue #29
---
 announce/message/message.go      | 13 +++++++++----
 announce/message/message_test.go | 15 +++++++++++++++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/announce/message/message.go b/announce/message/message.go
index 5d04de5..c39fd26 100644
--- a/announce/message/message.go
+++ b/announce/message/message.go
@@ -2,6 +2,7 @@ package message
 
 import (
 	"errors"
+	"strings"
 
 	"github.com/ipfs/go-cid"
 	"github.com/multiformats/go-multiaddr"
@@ -38,13 +39,17 @@ func (m *Message) SetAddrs(addrs []multiaddr.Multiaddr) {
 // GetAddrs reads the slice of Multiaddr that is stored in the Message as a
 // slice of []byte.
 func (m *Message) GetAddrs() ([]multiaddr.Multiaddr, error) {
-	addrs := make([]multiaddr.Multiaddr, len(m.Addrs))
-	for i := range m.Addrs {
-		var err error
-		addrs[i], err = multiaddr.NewMultiaddrBytes(m.Addrs[i])
+	addrs := make([]multiaddr.Multiaddr, 0, len(m.Addrs))
+	for _, addrBytes := range m.Addrs {
+		addr, err := multiaddr.NewMultiaddrBytes(addrBytes)
 		if err != nil {
+			if strings.Contains(err.Error(), "no protocol with code") {
+				// Ignore unknown protocols.
+				continue
+			}
 			return nil, err
 		}
+		addrs = append(addrs, addr)
 	}
 	return addrs, nil
 }
diff --git a/announce/message/message_test.go b/announce/message/message_test.go
index 120a591..b6e7636 100644
--- a/announce/message/message_test.go
+++ b/announce/message/message_test.go
@@ -73,3 +73,18 @@ func TestJSON(t *testing.T) {
 
 	require.Equal(t, msg, newMsg)
 }
+
+func TestUnknownProtocol(t *testing.T) {
+	// Encoded unknown protocol code 9999: /ip4/127.0.0.1/udp/1234/<proto-9999>
+	addrData := []byte{54, 9, 108, 111, 99, 97, 108, 104, 111, 115, 116, 145, 2, 4, 210, 143, 78}
+	_, err := multiaddr.NewMultiaddrBytes(addrData)
+	require.ErrorContains(t, err, "no protocol with code")
+
+	var msg message.Message
+	msg.SetAddrs([]multiaddr.Multiaddr{maddr1})
+	msg.Addrs = append(msg.Addrs, addrData)
+
+	addrs, err := msg.GetAddrs()
+	require.NoError(t, err)
+	require.Equal(t, 1, len(addrs))
+}