Extract the expire option from the response

diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c
index 07b624c5f1c383b2573b71b61fb7661a6736ddd5..079d75a0830bc76821e8fa9066db0579fc4e5751 100644 (file)
--- a/lib/dns/xfrin.c
+++ b/lib/dns/xfrin.c
@@ -142,7 +142,8 @@ struct dns_xfrin {
 
        xfrin_state_t state;
        uint32_t end_serial;
-       bool edns, is_ixfr;
+       uint32_t expireopt;
+       bool edns, is_ixfr, expireoptset;
 
        unsigned int nmsg;  /*%< Number of messages recvd */
        unsigned int nrecs; /*%< Number of records recvd */
@@ -834,7 +835,9 @@ xfrin_fail(dns_xfrin_t *xfr, isc_result_t result, const char *msg) {
                        dns_journal_destroy(&xfr->ixfr.journal);
                }
                if (xfr->done != NULL) {
-                       (xfr->done)(xfr->zone, NULL, result);
+                       (xfr->done)(xfr->zone,
+                                   xfr->expireoptset ? &xfr->expireopt : NULL,
+                                   result);
                        xfr->done = NULL;
                }
                xfr->shutdown_result = result;
@@ -1323,6 +1326,38 @@ failure:
        dns_xfrin_detach(&xfr);
 }
 
+static void
+get_edns_expire(dns_xfrin_t *xfr, dns_message_t *msg) {
+       isc_result_t result;
+       dns_rdata_t rdata = DNS_RDATA_INIT;
+       isc_buffer_t optbuf;
+       uint16_t optcode;
+       uint16_t optlen;
+
+       result = dns_rdataset_first(msg->opt);
+       if (result == ISC_R_SUCCESS) {
+               dns_rdataset_current(msg->opt, &rdata);
+               isc_buffer_init(&optbuf, rdata.data, rdata.length);
+               isc_buffer_add(&optbuf, rdata.length);
+               while (isc_buffer_remaininglength(&optbuf) >= 4) {
+                       optcode = isc_buffer_getuint16(&optbuf);
+                       optlen = isc_buffer_getuint16(&optbuf);
+                       /*
+                        * A EDNS EXPIRE response has a length of 4.
+                        */
+                       if (optcode != DNS_OPT_EXPIRE || optlen != 4) {
+                               isc_buffer_forward(&optbuf, optlen);
+                               continue;
+                       }
+                       xfr->expireopt = isc_buffer_getuint32(&optbuf);
+                       xfr->expireoptset = true;
+                       dns_zone_log(xfr->zone, ISC_LOG_DEBUG(1),
+                                    "got EDNS EXPIRE of %u", xfr->expireopt);
+                       break;
+               }
+       }
+}
+
 static void
 xfrin_recv_done(isc_result_t result, isc_region_t *region, void *arg) {
        dns_xfrin_t *xfr = (dns_xfrin_t *)arg;
@@ -1585,6 +1620,10 @@ xfrin_recv_done(isc_result_t result, isc_region_t *region, void *arg) {
        xfr->tsigctx = msg->tsigctx;
        msg->tsigctx = NULL;
 
+       if (!xfr->expireoptset && msg->opt != NULL) {
+               get_edns_expire(xfr, msg);
+       }
+
        switch (xfr->state) {
        case XFRST_GOTSOA:
                xfr->reqtype = dns_rdatatype_axfr;
@@ -1612,7 +1651,9 @@ xfrin_recv_done(isc_result_t result, isc_region_t *region, void *arg) {
                if (xfr->done != NULL) {
                        LIBDNS_XFRIN_DONE_CALLBACK_BEGIN(xfr, xfr->info,
                                                         result);
-                       (xfr->done)(xfr->zone, NULL, ISC_R_SUCCESS);
+                       (xfr->done)(xfr->zone,
+                                   xfr->expireoptset ? &xfr->expireopt : NULL,
+                                   ISC_R_SUCCESS);
                        xfr->done = NULL;
                        LIBDNS_XFRIN_DONE_CALLBACK_END(xfr, xfr->info, result);
                }