clnp: use ND_BYTES_BETWEEN() to get the bytes between two packet pointers.

[tcpdump] / print-isoclns.c

diff --git a/print-isoclns.c b/print-isoclns.c
index b356871475ddc9f08823228dea97ba41ff3ca0f7..882da50a874e28064c13f09e1bde642def561a60 100644 (file)
--- a/print-isoclns.c
+++ b/print-isoclns.c
@@ -1135,9 +1135,9 @@ clnp_print(netdissect_options *ndo,
 
         default:
             /* dump the PDU specific data */
-            if (length-(pptr-optr) > 0) {
+            if (length > ND_BYTES_BETWEEN(pptr, optr)) {
                 ND_PRINT("\n\t  undecoded non-header data, length %u", length-li);
-                print_unknown_data(ndo, pptr, "\n\t  ", length - (int)(pptr - optr));
+                print_unknown_data(ndo, pptr, "\n\t  ", length - ND_BYTES_BETWEEN(pptr, optr));
             }
         }