From: Vladimír Čunát <vladimir.cunat@nic.cz>
Date: Mon, 25 May 2026 09:29:46 +0000 (+0200)
Subject: iterate: fix DNS64 on CNAMEs
X-Git-Tag: v5.7.7~1^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3e987c5dc3537fe0db071e98af46fc2e39aff08;p=thirdparty%2Fknot-resolver.git

iterate: fix DNS64 on CNAMEs

It's a bit embarassing that the issue has lasted this long.
Overall the DNS64 module is slightly hacky/prototype-ish.
---

diff --git a/NEWS b/NEWS
index 48cbe974a..bb58791c8 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,7 @@ Bugfixes
 - respect disablement of QNAME case randomization even after TCP issues
 - cache: fix wrong TTL in some cases, typically 32768
 - reduce excessive caching of some uncommon failed answers (!1832)
+- dns64: fix CNAME problems again (#797, !1862)
 
 
 Knot Resolver 5.7.6 (2025-07-17)
diff --git a/lib/layer/iterate.c b/lib/layer/iterate.c
index 688f13cfe..e4dfcd692 100644
--- a/lib/layer/iterate.c
+++ b/lib/layer/iterate.c
@@ -801,6 +801,7 @@ static int process_answer(knot_pkt_t *pkt, struct kr_request *req)
 		/* Copy transitive flags from original query to CNAME followup. */
 		next->flags.TRACE = query->flags.TRACE;
 		next->flags.ALWAYS_CUT = query->flags.ALWAYS_CUT;
+		next->flags.DNS64_MARK = query->flags.DNS64_MARK;
 
 		/* Original query might have turned minimization off, revert. */
 		next->flags.NO_MINIMIZE = req->options.NO_MINIMIZE;
diff --git a/modules/dns64/dns64.lua b/modules/dns64/dns64.lua
index b4fb1ecb7..b93824222 100644
--- a/modules/dns64/dns64.lua
+++ b/modules/dns64/dns64.lua
@@ -150,6 +150,10 @@ function M.layer.consume(state, req, pkt)
 				qry.uid,
 				req.pool)
 		end
+		-- Also mark CNAMEs to be included.
+		if orig.qry_uid == qry.uid and orig.rr.type == kres.type.CNAME then
+			orig.to_wire = true
+		end
 	end
 	ffi.C.kr_ranked_rrarray_finalize(req.answ_selected, qry.uid, req.pool)
 	req:set_extended_error(kres.extended_error.FORGED, "BHD4: DNS64 synthesis")