diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c index 7ad2de0f56..2d1c1337ff 100644 --- a/lib/dns/xfrin.c +++ b/lib/dns/xfrin.c @@ -1312,6 +1312,61 @@ xfrin_recv_done(isc_task_t *task, isc_event_t *ev) { return; } + /* + * The question section should exist for SOA and in the first + * message of a AXFR or IXFR response. The question section + * may exist in the 2nd and subsequent messages in a AXFR or + * IXFR response. If the question section exists it should + * match the question that was sent. + */ + if (msg->counts[DNS_SECTION_QUESTION] > 1) { + xfrin_log(xfr, ISC_LOG_DEBUG(3), "too many questions (%u)", + msg->counts[DNS_SECTION_QUESTION]); + result = DNS_R_FORMERR; + goto failure; + } + + if ((xfr->state == XFRST_SOAQUERY || xfr->state == XFRST_INITIALSOA) && + msg->counts[DNS_SECTION_QUESTION] != 1) + { + xfrin_log(xfr, ISC_LOG_DEBUG(3), "missing question section"); + result = DNS_R_FORMERR; + goto failure; + } + + for (result = dns_message_firstname(msg, DNS_SECTION_QUESTION); + result == ISC_R_SUCCESS; + result = dns_message_nextname(msg, DNS_SECTION_QUESTION)) + { + dns_rdataset_t *rds; + + name = NULL; + dns_message_currentname(msg, DNS_SECTION_QUESTION, &name); + if (!dns_name_equal(name, &xfr->name)) { + result = DNS_R_FORMERR; + xfrin_log(xfr, ISC_LOG_DEBUG(3), + "question name mismatch"); + goto failure; + } + rds = ISC_LIST_HEAD(name->list); + INSIST(rds != NULL); + if (rds->type != xfr->reqtype) { + result = DNS_R_FORMERR; + xfrin_log(xfr, ISC_LOG_DEBUG(3), + "question type mismatch"); + goto failure; + } + if (rds->rdclass != xfr->rdclass) { + result = DNS_R_FORMERR; + xfrin_log(xfr, ISC_LOG_DEBUG(3), + "question class mismatch"); + goto failure; + } + } + if (result != ISC_R_NOMORE) { + goto failure; + } + /* * Does the server know about IXFR? If it doesn't we will get * a message with a empty answer section or a potentially a CNAME /