static int
l_pkt_set_ancount(lua_State *L)
{
ldns_pkt *p = (ldns_pkt*)lua_touserdata(L, 1);
uint16_t count = (uint16_t)lua_tonumber(L, 2);
if (!p) {
return 0;
}
(void)ldns_pkt_set_ancount(p, count);
return 0;
}
void truncation_check(evldns_server_request *srq)
{
ldns_pkt *req = srq->request;
ldns_pkt *resp = srq->response;
unsigned int bufsize = 512;
/* if it's TCP, business as usual */
if (srq->is_tcp) {
return;
}
/* otherwise, convert to wire format, if necessary */
if (!srq->wire_response) {
(void) ldns_pkt2wire(&srq->wire_response, resp, &srq->wire_resplen);
}
/* if it's under the RFC 1035 limit, we're OK */
if (srq->wire_resplen <= bufsize) {
return;
}
/* if the client used EDNS, use that new bufsize */
if (ldns_pkt_edns(req)) {
unsigned int ednssize = ldns_pkt_edns_udp_size(req);
if (ednssize > bufsize) {
bufsize = ednssize;
}
/* it fits - we're OK */
if (srq->wire_resplen <= bufsize) {
return;
}
}
/*
* if we got here, it didn't fit - throw away the
* existing wire buffer and the non-question sections
*/
free(srq->wire_response);
LDNS_rr_list_empty_rr_list(ldns_pkt_additional(resp));
LDNS_rr_list_empty_rr_list(ldns_pkt_authority(resp));
LDNS_rr_list_empty_rr_list(ldns_pkt_answer(resp));
/* set the TC bit and reset section counts */
ldns_pkt_set_tc(resp, true);
ldns_pkt_set_ancount(resp, 0);
ldns_pkt_set_nscount(resp, 0);
ldns_pkt_set_arcount(resp, 0);
/* and convert to wire format again */
(void) ldns_pkt2wire(&srq->wire_response, resp, &srq->wire_resplen);
}