From 7056766a84db0c784813187964e0b1718d7b1d04 Mon Sep 17 00:00:00 2001 From: Razvan Dimescu Date: Sat, 28 Mar 2026 22:42:33 +0200 Subject: [PATCH] fix: return NXDOMAIN for .local queries instead of SERVFAIL (#18) .local is reserved for mDNS (RFC 6762) and cannot be resolved by upstream DNS servers. Add it to is_special_use_domain() so queries like _grpc_config.localhost.local get an immediate NXDOMAIN instead of timing out and returning SERVFAIL. Co-authored-by: Claude Opus 4.6 --- src/ctx.rs | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/ctx.rs b/src/ctx.rs index 5ecb150..4fb926e 100644 --- a/src/ctx.rs +++ b/src/ctx.rs @@ -366,7 +366,11 @@ fn is_special_use_domain(qname: &str) -> bool { return true; } // NAT64 (RFC 8880) - qname == "ipv4only.arpa" + if qname == "ipv4only.arpa" { + return true; + } + // RFC 6762: .local is reserved for mDNS — never forward to upstream + qname == "local" || qname.ends_with(".local") } fn special_use_response(query: &DnsPacket, qname: &str, qtype: QueryType) -> DnsPacket {