Enable lame response detection even with disabled lame cache

Previously, when lame cache would be disabled by setting lame-ttl to 0,
it would also disable lame answer detection.  In this commit, we enable
the lame response detection even when the lame cache is disabled.  This
enables stopping answer processing early rather than going through the
whole answer processing flow.

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 5a65569e4dde553e2b748328cf7d8e997ef82aa4..9909ba4dcc95c19681838ad5a447577c84c49686 100644 (file)
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -10215,25 +10215,26 @@ rctx_badserver(respctx_t *rctx, isc_result_t result) {
  */
 static isc_result_t
 rctx_lameserver(respctx_t *rctx) {
-       isc_result_t result;
+       isc_result_t result = ISC_R_SUCCESS;
        fetchctx_t *fctx = rctx->fctx;
        resquery_t *query = rctx->query;
 
-       if (fctx->res->lame_ttl == 0 || ISFORWARDER(query->addrinfo) ||
-           !is_lame(fctx, query->rmessage))
-       {
+       if (ISFORWARDER(query->addrinfo) || !is_lame(fctx, query->rmessage)) {
                return (ISC_R_SUCCESS);
        }
 
        inc_stats(fctx->res, dns_resstatscounter_lame);
        log_lame(fctx, query->addrinfo);
-       result = dns_adb_marklame(fctx->adb, query->addrinfo, &fctx->name,
-                                 fctx->type, rctx->now + fctx->res->lame_ttl);
-       if (result != ISC_R_SUCCESS) {
-               isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
-                             DNS_LOGMODULE_RESOLVER, ISC_LOG_ERROR,
-                             "could not mark server as lame: %s",
-                             isc_result_totext(result));
+       if (fctx->res->lame_ttl != 0) {
+               result = dns_adb_marklame(fctx->adb, query->addrinfo,
+                                         &fctx->name, fctx->type,
+                                         rctx->now + fctx->res->lame_ttl);
+               if (result != ISC_R_SUCCESS) {
+                       isc_log_write(dns_lctx, DNS_LOGCATEGORY_RESOLVER,
+                                     DNS_LOGMODULE_RESOLVER, ISC_LOG_ERROR,
+                                     "could not mark server as lame: %s",
+                                     isc_result_totext(result));
+               }
        }
        rctx->broken_server = DNS_R_LAME;
        rctx->next_server = true;