From 73e566bf16341c2064598ccf2a060366113eeccc Mon Sep 17 00:00:00 2001
From: Ronan Pigott <ronan@rjp.ie>
Date: Wed, 21 Aug 2024 09:41:35 -0700
Subject: [PATCH] resolved: introduce link_set_default_route

---
 src/resolve/resolved-link.c | 14 ++++++++++++++
 src/resolve/resolved-link.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c
index bb43a73de42..01fa5878a68 100644
--- a/src/resolve/resolved-link.c
+++ b/src/resolve/resolved-link.c
@@ -766,6 +766,20 @@ void link_next_dns_server(Link *l, DnsServer *if_current) {
         link_set_dns_server(l, l->dns_servers);
 }
 
+void link_set_default_route(Link *l, bool b) {
+        assert(l);
+
+        if (l->default_route == b)
+                return;
+
+        l->default_route = b;
+
+        /* If we are currently using the fallback servers, changing a link to be default-route means
+         * we should reconsider whether or not the fallback servers are necessary. */
+        if (b && dns_server_is_fallback(l->manager->current_dns_server))
+                manager_set_dns_server(l->manager, NULL);
+}
+
 DnsOverTlsMode link_get_dns_over_tls_mode(Link *l) {
         assert(l);
 
diff --git a/src/resolve/resolved-link.h b/src/resolve/resolved-link.h
index 0695a6ff838..482a4b4148c 100644
--- a/src/resolve/resolved-link.h
+++ b/src/resolve/resolved-link.h
@@ -99,6 +99,7 @@ void link_allocate_scopes(Link *l);
 DnsServer* link_set_dns_server(Link *l, DnsServer *s);
 DnsServer* link_get_dns_server(Link *l);
 void link_next_dns_server(Link *l, DnsServer *if_current);
+void link_set_default_route(Link *l, bool b);
 
 DnssecMode link_get_dnssec_mode(Link *l);
 bool link_dnssec_supported(Link *l);
-- 
2.47.3