diff options
Diffstat (limited to 'cachedb/cachedb.c')
| -rw-r--r-- | cachedb/cachedb.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/cachedb/cachedb.c b/cachedb/cachedb.c index b07743d85259..245daa986967 100644 --- a/cachedb/cachedb.c +++ b/cachedb/cachedb.c @@ -390,6 +390,15 @@ prep_data(struct module_qstate* qstate, struct sldns_buffer* buf) if(!qstate->return_msg || !qstate->return_msg->rep) return 0; + /* do not store failures like SERVFAIL in the cachedb, this avoids + * overwriting expired, valid, content with broken content. */ + if(FLAGS_GET_RCODE(qstate->return_msg->rep->flags) != + LDNS_RCODE_NOERROR && + FLAGS_GET_RCODE(qstate->return_msg->rep->flags) != + LDNS_RCODE_NXDOMAIN && + FLAGS_GET_RCODE(qstate->return_msg->rep->flags) != + LDNS_RCODE_YXDOMAIN) + return 0; /* We don't store the reply if its TTL is 0 unless serve-expired is * enabled. Such a reply won't be reusable and simply be a waste for * the backend. It's also compatible with the default behavior of @@ -542,10 +551,16 @@ parse_data(struct module_qstate* qstate, struct sldns_buffer* buf) verbose(VERB_ALGO, "cachedb msg expired"); /* If serve-expired is enabled, we still use an expired message * setting the TTL to 0. */ - if(qstate->env->cfg->serve_expired) - adjust = -1; - else + if(!qstate->env->cfg->serve_expired || + (FLAGS_GET_RCODE(qstate->return_msg->rep->flags) + != LDNS_RCODE_NOERROR && + FLAGS_GET_RCODE(qstate->return_msg->rep->flags) + != LDNS_RCODE_NXDOMAIN && + FLAGS_GET_RCODE(qstate->return_msg->rep->flags) + != LDNS_RCODE_YXDOMAIN)) return 0; /* message expired */ + else + adjust = -1; } verbose(VERB_ALGO, "cachedb msg adjusted down by %d", (int)adjust); adjust_msg_ttl(qstate->return_msg, adjust); |