ipv6: set the snapshot length for the payload correctly.

Cut off the snapshot length to the end of the IP payload or the end of
the data in which it's contained, whichever comes first.

diff --git a/print-ip6.c b/print-ip6.c
index aaf31b4ee4880021c5f8eb17b6b299de5421a546..269b41fb2a7aabc87b2cf811126734728a49b027 100644 (file)
--- a/print-ip6.c
+++ b/print-ip6.c
@@ -301,9 +301,11 @@ ip6_print(netdissect_options *ndo, const u_char *bp, u_int length)
        ND_TCHECK_SIZE(ip6);
 
        /*
-        * Cut off the snapshot length to the end of the IP payload.
+        * Cut off the snapshot length to the end of the IP payload
+        * or the end of the data in which it's contained, whichever
+        * comes first.
         */
-       if (!nd_push_snaplen(ndo, bp, len)) {
+       if (!nd_push_snaplen(ndo, bp, ND_MIN(length, len))) {
                (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC,
                        "%s: can't push snaplen on buffer stack", __func__);
        }