ignore blocks which are too big

i.e. greater than what we can represent in a compressed pointer

diff --git a/src/lib/util/dns.c b/src/lib/util/dns.c
index ef5a789ac7b979049c1fb87e6fc608793b19809c..f63836bfe9ad025a259273bc6822767df8b339b0 100644 (file)
--- a/src/lib/util/dns.c
+++ b/src/lib/util/dns.c
@@ -52,6 +52,8 @@ fr_dns_labels_t *fr_dns_labels_init(TALLOC_CTX *ctx, uint8_t const *packet, int
        return lb;
 }
 
+#define MAX_OFFSET (1 << 14)
+
 static int dns_label_add(fr_dns_labels_t *lb, uint8_t const *start, uint8_t const *end)
 {
        size_t offset, size = end - start;
@@ -67,15 +69,15 @@ static int dns_label_add(fr_dns_labels_t *lb, uint8_t const *start, uint8_t cons
        fr_assert(end >= start);
 
        offset = start - lb->start;
-       fr_assert(offset < 65536);
-       fr_assert(size < 65535);
-       fr_assert((offset + size) < 65535);
 
-       FR_PROTO_TRACE("adding label at offset %zu", offset);
+       /*
+        *      DNS packets can be up to 64K in size, but the
+        *      compressed pointers can only be up to 2^14 in size.
+        *      So we just ignore offsets which are greater than 2^14.
+        */
+       if ((offset + size) >= MAX_OFFSET) return 0;
 
-       if (offset > 65535) return -1;
-       if (size > 65535) return -1;
-       if ((offset + size) > 65535) return -1;
+       FR_PROTO_TRACE("adding label at offset %zu", offset);
 
        /*
         *      We add blocks append-only.  No adding new blocks in