+static int gsz_addr(const typeinfo *typei, adns_rrtype type) {
+ return type & adns__qtf_bigaddr ?
+ sizeof(adns_rr_addr) : sizeof(adns_rr_addr_v4only);
+}
+
+static unsigned addr_rrtypes(adns_state ads, adns_rrtype type,
+ adns_queryflags qf) {
+ /* Return a mask of addr_rf_... flags indicating which address families are
+ * wanted, given a query type and flags.
+ */
+
+ adns_queryflags permitaf= 0;
+ unsigned want= 0;
+
+ if (!(type & adns__qtf_bigaddr))
+ qf= (qf & ~adns_qf_want_allaf) | adns_qf_want_ipv4;
+ else {
+ if (!(qf & adns_qf_want_allaf)) {
+ qf |= (type & adns__qtf_manyaf) ?
+ adns_qf_want_allaf : adns_qf_want_ipv4;
+ }
+ if (ads->iflags & adns_if_permit_ipv4) permitaf |= adns_qf_want_ipv4;
+ if (ads->iflags & adns_if_permit_ipv6) permitaf |= adns_qf_want_ipv6;
+ if (qf & permitaf) qf &= permitaf | ~adns_qf_want_allaf;
+ }
+
+ if (qf & adns_qf_want_ipv4) want |= addr_rf_a;
+ if (qf & adns_qf_want_ipv6) want |= addr_rf_aaaa;
+
+ return want;
+}
+
+static void icb_addr(adns_query parent, adns_query child);
+
+static void addr_subqueries(adns_query qu, struct timeval now,
+ adns_queryflags qf_extra,
+ const byte *qd_dgram, int qd_dglen) {
+ int i, err, id;
+ adns_query cqu;
+ adns_queryflags qf= (qu->flags & ~adns_qf_search) | qf_extra;
+ adns_rrtype qtf= qu->answer->type & adns__qtf_deref;
+ unsigned which= qu->ctx.tinfo.addr.want & ~qu->ctx.tinfo.addr.have;
+ qcontext ctx;
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.callback= icb_addr;
+ for (i=0; i<addr_nrrtypes; i++) {
+ if (!(which & (1 << i))) continue;
+ err= adns__mkquery_frdgram(qu->ads, &qu->vb, &id, qd_dgram,qd_dglen,
+ DNS_HDRSIZE, addr_all_rrtypes[i], qf);
+ if (err) goto x_error;
+ err= adns__internal_submit(qu->ads, &cqu, qu, &tinfo_addrsub,
+ addr_all_rrtypes[i] | qtf,
+ &qu->vb, id, qf, now, &ctx);
+ if (err) goto x_error;
+ cqu->answer->rrsz= qu->answer->rrsz;
+ }
+ qu->state= query_childw;
+ LIST_LINK_TAIL(qu->ads->childw, qu);
+ return;
+
+x_error:
+ adns__query_fail(qu, err);
+}
+
+static adns_status addr_submit(adns_query parent, adns_query *query_r,
+ vbuf *qumsg_vb, int id, unsigned want,
+ adns_queryflags flags, struct timeval now,
+ qcontext *ctx) {
+ /* This is effectively a substitute for adns__internal_submit, intended for
+ * the case where the caller (possibly) only wants a subset of the
+ * available record types. The memory management and callback rules are
+ * the same as for adns__internal_submit.
+ *
+ * Some differences: the query is linked onto the parent's children
+ * list before exit (though the parent's state is not changed, and
+ * it is not linked into the childw list queue); and we set the
+ * `tinfo' portion of the context structure (yes, modifying *ctx),
+ * since this is, in fact, the main purpose of this function.
+ */
+
+ adns_state ads= parent->ads;
+ adns_query qu;
+ adns_status err;
+ adns_rrtype type= ((adns_r_addr & adns_rrt_reprmask) |
+ (parent->answer->type & ~adns_rrt_reprmask));
+
+ ctx->tinfo.addr.want= want;
+ ctx->tinfo.addr.have= 0;
+ err= adns__internal_submit(ads, &qu, parent, adns__findtype(adns_r_addr),
+ type, qumsg_vb, id, flags, now, ctx);
+ if (err) return err;
+
+ *query_r= qu;
+ return adns_s_ok;
+}
+
+static adns_status append_addrs(adns_query qu, size_t rrsz,
+ adns_rr_addr **dp, int *dlen,
+ const adns_rr_addr *sp, int slen) {
+ /* Append a vector of slen addr records, each of size rrsz, starting at ap,
+ * to a vector starting at *dp, of length *dlen. On successful completion,
+ * *dp and *dlen are updated.
+ */
+
+ size_t drrsz= *dlen*rrsz, srrsz= slen*rrsz;
+ byte *p;
+
+ if (!slen) return adns_s_ok;
+ p= adns__alloc_interim(qu, drrsz + srrsz);
+ if (!p) R_NOMEM;
+ if (*dlen) {
+ memcpy(p, *dp, drrsz);
+ adns__free_interim(qu, *dp);
+ }
+ memcpy(p + drrsz, sp, srrsz);
+ *dlen += slen;
+ *dp= (adns_rr_addr *)p;
+ return adns_s_ok;
+}
+
+static void propagate_ttl(adns_query to, adns_query from)
+ { if (to->expires > from->expires) to->expires= from->expires; }
+
+static adns_status copy_cname_from_child(adns_query parent, adns_query child) {
+ adns_answer *pans= parent->answer, *cans= child->answer;
+ size_t n= strlen(cans->cname) + 1;
+
+ pans->cname= adns__alloc_preserved(parent, n);
+ if (!pans->cname) R_NOMEM;
+ memcpy(pans->cname, cans->cname, n);
+ return adns_s_ok;
+}
+
+static void done_addr_type(adns_query qu, adns_rrtype type) {
+ unsigned f= addr_rrtypeflag(type);
+ assert(f); qu->ctx.tinfo.addr.have |= f;
+}
+
+static void icb_addr(adns_query parent, adns_query child) {
+ adns_state ads= parent->ads;
+ adns_answer *pans= parent->answer, *cans= child->answer;
+ struct timeval now;
+ adns_status err;
+ adns_queryflags qf;
+ int id, r;
+
+ propagate_ttl(parent, child);
+
+ if (!(child->flags & adns__qf_addr_cname) &&
+ (parent->flags & adns__qf_addr_answer) &&
+ (!!pans->cname != !!cans->cname ||
+ (pans->cname && strcmp(pans->cname, cans->cname)))) {
+ /* 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);
+ r= gettimeofday(&now, 0); if (r) goto x_gtod;
+ qf= adns__qf_addr_cname;
+ if (!(parent->flags & adns_qf_cname_loose)) qf |= adns_qf_cname_forbid;
+ addr_subqueries(parent, now, qf, 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, and the name doesn't exist. Try
+ * the next one.
+ */
+
+ adns__cancel_children(parent);
+ adns__free_interim(parent, pans->rrs.bytes);
+ pans->rrs.bytes= 0; pans->nrrs= 0;
+ r= gettimeofday(&now, 0); if (r) 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, 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:
+ /* We have our own error handling, because adns__must_gettimeofday
+ * handles errors by calling adns_globalsystemfailure, which would
+ * reenter the query processing logic. */
+ 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);
+}
+