From: Jacek Migacz <jmigacz@redhat.com>
Date: Wed, 27 Jul 2022 16:38:12 +0000 (+0200)
Subject: resolved: fix single-label resolution over DNS
X-Git-Tag: v252-rc1~541
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=ff0a5070d45f20df7744b1090892be797bf18365;p=thirdparty%2Fsystemd.git

resolved: fix single-label resolution over DNS

Fixes: #23494 (when ResolveUnicastSingleLabel=yes)
---

diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 473e397013b..8fd987bd824 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -692,6 +692,11 @@ DnsScopeMatch dns_scope_good_domain(
                 if (has_search_domains && dns_name_is_single_label(domain))
                         return DNS_SCOPE_YES_BASE + 1;
 
+                /* If ResolveUnicastSingleLabel=yes and the query is single-label, then bump match result
+                   to prevent LLMNR monopoly among candidates. */
+                if (s->manager->resolve_unicast_single_label && dns_name_is_single_label(domain))
+                        return DNS_SCOPE_YES_BASE + 1;
+
                 /* Let's return the number of labels in the best matching result */
                 if (n_best >= 0) {
                         assert(n_best <= DNS_SCOPE_YES_END - DNS_SCOPE_YES_BASE);