[ldns-users] Various fixes

[Vitaly Magerya]

Hi, folks. I've been writing a bind9-host replacement using ldns,
and there's a number of problems with the library I've run into:

1. ldns_resolver_nameservers_randomize (resolver.c) shuffles
_nameservers array, but does not shuffle _rtt array; I think
both arrays should be kept in sync.

2. ldns_dname_cat_clone (dname.c) does not check if the resulting
domain name is too long. I'm not sure if this is by design.

3. ldns_pkt_push_rr (packet.c) does not check for errors, and
always returns true.

I'm attaching a patch to fix these problems (it's rather trivial),
hope you'll find it useful.
-------------- next part --------------
diff --git a/dname.c b/dname.c
--- a/dname.c
+++ b/dname.c
@@ -53,6 +53,9 @@
 
 	/* we overwrite the nullbyte of rd1 */
 	new_size = left_size + ldns_rdf_size(rd2);
+	if (new_size > LDNS_MAX_DOMAINLEN) {
+		return NULL;
+	}
 	buf = LDNS_XMALLOC(uint8_t, new_size);
 	if (!buf) {
 		return NULL;
diff --git a/packet.c b/packet.c
--- a/packet.c
+++ b/packet.c
@@ -649,19 +649,27 @@
 {
 	switch(section) {
 		case LDNS_SECTION_QUESTION:
-			ldns_rr_list_push_rr(ldns_pkt_question(packet), rr);
+			if (!ldns_rr_list_push_rr(ldns_pkt_question(packet), rr)) {
+				return false;
+			}
 			ldns_pkt_set_qdcount(packet, ldns_pkt_qdcount(packet) + 1);
 			break;
 		case LDNS_SECTION_ANSWER:
-			ldns_rr_list_push_rr(ldns_pkt_answer(packet), rr);
+			if (!ldns_rr_list_push_rr(ldns_pkt_answer(packet), rr)) {
+				return false;
+			}
 			ldns_pkt_set_ancount(packet, ldns_pkt_ancount(packet) + 1);
 			break;
 		case LDNS_SECTION_AUTHORITY:
-			ldns_rr_list_push_rr(ldns_pkt_authority(packet), rr);
+			if (!ldns_rr_list_push_rr(ldns_pkt_authority(packet), rr)) {
+				return false;
+			}
 			ldns_pkt_set_nscount(packet, ldns_pkt_nscount(packet) + 1);
 			break;
 		case LDNS_SECTION_ADDITIONAL:
-			ldns_rr_list_push_rr(ldns_pkt_additional(packet), rr);
+			if (!ldns_rr_list_push_rr(ldns_pkt_additional(packet), rr)) {
+				return false;
+			}
 			ldns_pkt_set_arcount(packet, ldns_pkt_arcount(packet) + 1);
 			break;
 		case LDNS_SECTION_ANY:
diff --git a/resolver.c b/resolver.c
--- a/resolver.c
+++ b/resolver.c
@@ -1333,17 +1333,22 @@
 ldns_resolver_nameservers_randomize(ldns_resolver *r)
 {
 	uint16_t i, j;
-	ldns_rdf **ns, *tmp;
+	ldns_rdf **ns, *tmpns;
+	size_t *rtt, tmprtt;
 
 	/* should I check for ldns_resolver_random?? */
 	assert(r != NULL);
 
 	ns = ldns_resolver_nameservers(r);
+	rtt = ldns_resolver_rtt(r);
 	for (i = 0; i < ldns_resolver_nameserver_count(r); i++) {
 		j = ldns_get_random() % ldns_resolver_nameserver_count(r);
-		tmp = ns[i];
+		tmpns = ns[i];
 		ns[i] = ns[j];
-		ns[j] = tmp;
+		ns[j] = tmpns;
+		tmprtt = rtt[i];
+		rtt[i] = rtt[j];
+		rtt[j] = tmprtt;
 	}
 	ldns_resolver_set_nameservers(r, ns);
 }