Merge pull request #22231 from yuwata/resolve-synthesize

resolve: synthesize several filtered name

src/resolve/resolved-bus.c

@@ -433,9 +433,6 @@ static int bus_method_resolve_hostname(sd_bus_message *message, void *userdata,
         if (r != 0)
                 return r;
 
-        if (dns_name_is_empty(hostname))
-                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Empty hostname");
-
         r = dns_name_is_valid(hostname);
         if (r < 0)
                 return r;
@@ -743,9 +740,6 @@ static int bus_method_resolve_record(sd_bus_message *message, void *userdata, sd
         if (ifindex < 0)
                 return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index");
 
-        if (dns_name_is_empty(name))
-                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Empty name");
-
         r = dns_name_is_valid(name);
         if (r < 0)
                 return r;

src/resolve/resolved-dns-scope.c

@@ -613,6 +613,10 @@ DnsScopeMatch dns_scope_good_domain(
         if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, false, false) & flags) == 0)
                 return DNS_SCOPE_NO;
 
+        /* Never resolve empty name. */
+        if (dns_name_is_empty(domain))
+                return DNS_SCOPE_NO;
+
         /* Never resolve any loopback hostname or IP address via DNS, LLMNR or mDNS. Instead, always rely on
          * synthesized RRs for these. */
         if (is_localhost(domain) ||

src/resolve/resolved-dns-synthesize.c

@@ -394,7 +394,18 @@ int dns_synthesize_answer(
 
                 name = dns_resource_key_name(key);
 
-                if (is_localhost(name)) {
+                if (dns_name_is_empty(name)) {
+                        /* Do nothing. */
+
+                } else if (dns_name_endswith(name, "0.in-addr.arpa") > 0 ||
+                           dns_name_equal(name, "255.255.255.255.in-addr.arpa") > 0 ||
+                           dns_name_equal(name, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0 ||
+                           dns_name_endswith(name, "invalid") > 0) {
+
+                        nxdomain = true;
+                        continue;
+
+                } else if (is_localhost(name)) {
 
                         r = synthesize_localhost_rr(m, key, ifindex, &answer);
                         if (r < 0)

src/resolve/resolved-varlink.c

@@ -303,9 +303,6 @@ static int vl_method_resolve_hostname(Varlink *link, JsonVariant *parameters, Va
         if (p.ifindex < 0)
                 return varlink_error_invalid_parameter(link, JSON_VARIANT_STRING_CONST("ifindex"));
 
-        if (dns_name_is_empty(p.name))
-                return varlink_error_invalid_parameter(link, JSON_VARIANT_STRING_CONST("name"));
-
         r = dns_name_is_valid(p.name);
         if (r < 0)
                 return r;