1 files changed, 11 insertions, 0 deletions
diff --git a/lib/dns/include/dns/rdata.h b/lib/dns/include/dns/rdata.h
index e3183c0..c3e7db6 100644
--- a/lib/dns/include/dns/rdata.h
+++ b/lib/dns/include/dns/rdata.h
@@ -147,6 +147,17 @@ struct dns_rdata {
 	(((rdata)->flags & ~(DNS_RDATA_UPDATE|DNS_RDATA_OFFLINE)) == 0)
 
 /*
+ * The maximum length of a RDATA that can be sent on the wire.
+ * Max packet size (65535) less header (12), less name (1), type (2),
+ * class (2), ttl(4), length (2).
+ *
+ * None of the defined types that support name compression can exceed
+ * this and all new types are to be sent uncompressed.
+ */
+
+#define DNS_RDATA_MAXLENGTH	65512U
+
+/*
  * Flags affecting rdata formatting style.  Flags 0xFFFF0000
  * are used by masterfile-level formatting and defined elsewhere.
  * See additional comments at dns_rdata_tofmttext().