resolved: teach resolved the difference between "routing" and "search" domains

Following the changes to expose the "routing" and "search" domain concepts in networkd, actually make resolved use
them. It will now use routing domains exclusively for making DNS routing decisions, and use search domains additionally
for extending single-label names.

1 files changed, 39 insertions, 17 deletions

diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c
index 8f0afc185b..37dd4a6e78 100644
--- a/src/resolve/resolved-link.c
+++ b/src/resolve/resolved-link.c
@@ -377,38 +377,60 @@ clear:
         return r;
 }
 
+static int link_update_search_domain_one(Link *l, const char *name, bool route_only) {
+        DnsSearchDomain *d;
+        int r;
+
+        r = dns_search_domain_find(l->search_domains, name, &d);
+        if (r < 0)
+                return r;
+        if (r > 0)
+                dns_search_domain_move_back_and_unmark(d);
+        else {
+                r = dns_search_domain_new(l->manager, &d, DNS_SEARCH_DOMAIN_LINK, l, name);
+                if (r < 0)
+                        return r;
+        }
+
+        d->route_only = route_only;
+        return 0;
+}
+
 static int link_update_search_domains(Link *l) {
-        _cleanup_strv_free_ char **domains = NULL;
+        _cleanup_strv_free_ char **sdomains = NULL, **rdomains = NULL;
         char **i;
-        int r;
+        int r, q;
 
         assert(l);
 
-        r = sd_network_link_get_search_domains(l->ifindex, &domains);
-        if (r == -ENODATA) {
+        r = sd_network_link_get_search_domains(l->ifindex, &sdomains);
+        if (r < 0 && r != -ENODATA)
+                goto clear;
+
+        q = sd_network_link_get_route_domains(l->ifindex, &rdomains);
+        if (q < 0 && q != -ENODATA) {
+                r = q;
+                goto clear;
+        }
+
+        if (r == -ENODATA && q == -ENODATA) {
                 /* networkd knows nothing about this interface, and that's fine. */
                 r = 0;
                 goto clear;
         }
-        if (r < 0)
-                goto clear;
 
         dns_search_domain_mark_all(l->search_domains);
 
-        STRV_FOREACH(i, domains) {
-                DnsSearchDomain *d;
-
-                r = dns_search_domain_find(l->search_domains, *i, &d);
+        STRV_FOREACH(i, sdomains) {
+                r = link_update_search_domain_one(l, *i, false);
                 if (r < 0)
                         goto clear;
+        }
 
-                if (r > 0)
-                        dns_search_domain_move_back_and_unmark(d);
-                else {
-                        r = dns_search_domain_new(l->manager, NULL, DNS_SEARCH_DOMAIN_LINK, l, *i);
-                        if (r < 0)
-                                goto clear;
-                }
+        STRV_FOREACH(i, rdomains) {
+                r = link_update_search_domain_one(l, *i, true);
+                if (r < 0)
+                        goto clear;
         }
 
         dns_search_domain_unlink_marked(l->search_domains);