+ if (!(child->flags & adns__qf_addr_cname) &&
+ (parent->flags & adns__qf_addr_answer) &&
+ (!!pans->cname != !!cans->cname ||
+ (pans->cname && strcmp(pans->cname, cans->cname) != 0))) {
+ /* We've detected an inconsistency in CNAME records, and must deploy
+ * countermeasures.
+ */
+
+ if (!pans->cname) {
+ /* The child has a CNAME record, but the parent doesn't. We must
+ * discard all of the parent's addresses, and substitute the child's.
+ */
+
+ assert(pans->rrsz == cans->rrsz);
+ adns__free_interim(parent, pans->rrs.bytes);
+ adns__transfer_interim(child, parent, cans->rrs.bytes);
+ pans->rrs.bytes = cans->rrs.bytes;
+ pans->nrrs = cans->nrrs;
+ parent->ctx.tinfo.addr.have = 0;
+ done_addr_type(parent, cans->type);
+ err = copy_cname_from_child(parent, child); if (err) goto x_err;
+ }
+
+ /* We've settled on the CNAME (now) associated with the parent, which
+ * already has appropriate address records. Build a query datagram for
+ * this name so that we can issue child queries for the missing address
+ * families. The child's vbuf looks handy for this.
+ */
+ err = adns__mkquery(ads, &child->vb, &id, pans->cname,
+ strlen(pans->cname), &tinfo_addrsub,
+ adns_r_addr, parent->flags);
+ if (err) goto x_err;
+
+ /* Now cancel the remaining children, and try again with the CNAME we've
+ * settled on.
+ */
+ adns__cancel_children(parent);
+ if (gettimeofday(&now, 0)) goto x_gtod;
+ addr_subqueries(parent, now, adns__qf_addr_cname,
+ child->vb.buf, child->vb.used);
+ return;
+ }
+
+ if (cans->cname && !pans->cname) {
+ err = copy_cname_from_child(parent, child);
+ if (err) goto x_err;
+ }
+
+ if ((parent->flags & adns_qf_search) &&
+ !pans->cname && cans->status == adns_s_nxdomain) {
+ /* We're searching a list of suffixes, this is the first answer, and it
+ * tells us that the name doesn't exist. Try the next one.
+ */
+
+ if (parent->expires > child->expires) parent->expires = child->expires;
+ adns__cancel_children(parent);
+ adns__free_interim(parent, pans->rrs.bytes);
+ pans->rrs.bytes = 0; pans->nrrs = 0;
+ if (gettimeofday(&now, 0)) goto x_gtod;
+ adns__search_next(ads, parent, now);
+ return;
+ }
+
+ if (cans->status && cans->status != adns_s_nodata)
+ { err = cans->status; goto x_err; }
+
+ assert(pans->rrsz == cans->rrsz);
+ err = append_addrs(parent, child, pans->rrsz,
+ &pans->rrs.addr, &pans->nrrs,
+ cans->rrs.addr, cans->nrrs);
+ if (err) goto x_err;
+ done_addr_type(parent, cans->type);
+
+ if (parent->children.head) LIST_LINK_TAIL(ads->childw, parent);
+ else if (!pans->nrrs) adns__query_fail(parent, adns_s_nodata);
+ else adns__query_done(parent);
+ parent->flags |= adns__qf_addr_answer;
+ return;
+
+x_gtod:
+ adns__diag(ads, -1, parent, "gettimeofday failed: %s", strerror(errno));
+ err = adns_s_systemfail;
+ goto x_err;
+
+x_err:
+ adns__query_fail(parent, err);
+}
+
+static void qs_addr(adns_query qu, struct timeval now)
+{
+ if (!qu->ctx.tinfo.addr.want) {
+ qu->ctx.tinfo.addr.want =
+ addr_rrtypes(qu->ads, qu->answer->type, qu->flags);
+ qu->ctx.tinfo.addr.have = 0;
+ }
+ addr_subqueries(qu, now, 0, qu->query_dgram, qu->query_dglen);