static int reply_recv(struct dnsc *dnsc, struct mbuf *mb)
{
struct dns_query *q = NULL;
uint32_t i, j, nv[3];
struct dnsquery dq;
int err = 0;
if (!dnsc || !mb)
return EINVAL;
dq.name = NULL;
if (dns_hdr_decode(mb, &dq.hdr) || !dq.hdr.qr) {
err = EBADMSG;
goto out;
}
err = dns_dname_decode(mb, &dq.name, 0);
if (err)
goto out;
if (mbuf_get_left(mb) < 4) {
err = EBADMSG;
goto out;
}
dq.type = ntohs(mbuf_read_u16(mb));
dq.dnsclass = ntohs(mbuf_read_u16(mb));
q = list_ledata(hash_lookup(dnsc->ht_query, hash_joaat_str_ci(dq.name),
query_cmp_handler, &dq));
if (!q) {
err = ENOENT;
goto out;
}
/* try next server */
if (dq.hdr.rcode == DNS_RCODE_SRV_FAIL && q->ntx < *q->srvc) {
if (!q->tc) /* try next UDP server immediately */
tmr_start(&q->tmr, 0, udp_timeout_handler, q);
err = EPROTO;
goto out;
}
nv[0] = dq.hdr.nans;
nv[1] = dq.hdr.nauth;
nv[2] = dq.hdr.nadd;
for (i=0; i<ARRAY_SIZE(nv); i++) {
for (j=0; j<nv[i]; j++) {
struct dnsrr *rr = NULL;
err = dns_rr_decode(mb, &rr, 0);
if (err) {
query_handler(q, err, NULL, NULL, NULL, NULL);
mem_deref(q);
goto out;
}
list_append(&q->rrlv[i], &rr->le_priv, rr);
}
}
if (q->type == DNS_QTYPE_AXFR) {
struct dnsrr *rrh, *rrt;
rrh = list_ledata(list_head(&q->rrlv[0]));
rrt = list_ledata(list_tail(&q->rrlv[0]));
/* Wait for last AXFR reply with terminating SOA record */
if (dq.hdr.rcode == DNS_RCODE_OK && dq.hdr.nans > 0 &&
(!rrt || rrt->type != DNS_TYPE_SOA || rrh == rrt)) {
DEBUG_INFO("waiting for last SOA record in reply\n");
goto out;
}
}
query_handler(q, 0, &dq.hdr, &q->rrlv[0], &q->rrlv[1], &q->rrlv[2]);
mem_deref(q);
out:
mem_deref(dq.name);
return err;
}
static void decode_dns_query(struct dns_server *srv,
const struct sa *src, struct mbuf *mb)
{
struct list rrl = LIST_INIT;
struct dnshdr hdr;
struct le *le;
char *qname = NULL;
size_t start, end;
uint16_t type, dnsclass;
int err = 0;
start = mb->pos;
end = mb->end;
if (dns_hdr_decode(mb, &hdr) || hdr.qr || hdr.nq != 1) {
DEBUG_WARNING("unable to decode query header\n");
return;
}
err = dns_dname_decode(mb, &qname, start);
if (err) {
DEBUG_WARNING("unable to decode query name\n");
goto out;
}
if (mbuf_get_left(mb) < 4) {
err = EBADMSG;
DEBUG_WARNING("unable to decode query type/class\n");
goto out;
}
type = ntohs(mbuf_read_u16(mb));
dnsclass = ntohs(mbuf_read_u16(mb));
DEBUG_INFO("dnssrv: type=%s query-name='%s'\n",
dns_rr_typename(type), qname);
if (dnsclass == DNS_CLASS_IN) {
dns_server_match(srv, &rrl, qname, type);
}
hdr.qr = true;
hdr.tc = false;
hdr.rcode = DNS_RCODE_OK;
hdr.nq = 1;
hdr.nans = list_count(&rrl);
mb->pos = start;
err = dns_hdr_encode(mb, &hdr);
if (err)
goto out;
mb->pos = end;
DEBUG_INFO("dnssrv: @@ found %u answers for %s\n",
list_count(&rrl), qname);
for (le = rrl.head; le; le = le->next) {
struct dnsrr *rr = le->data;
err = dns_rr_encode(mb, rr, 0, NULL, start);
if (err)
goto out;
}
mb->pos = start;
(void)udp_send(srv->us, src, mb);
out:
list_clear(&rrl);
mem_deref(qname);
}
