+ ND_PRINT((ndo, ", RFC2117-encoding"));
+
+ if (len < 4)
+ goto trunc;
+ ND_TCHECK(pim->pim_cksum);
+ ND_PRINT((ndo, ", cksum 0x%04x ", EXTRACT_16BITS(&pim->pim_cksum)));
+ if (EXTRACT_16BITS(&pim->pim_cksum) == 0) {
+ ND_PRINT((ndo, "(unverified)"));
+ } else {
+ if (PIM_TYPE(pim->pim_typever) == PIMV2_TYPE_REGISTER) {
+ /*
+ * The checksum only covers the packet header,
+ * not the encapsulated packet.
+ */
+ cksum_status = pimv2_check_checksum(ndo, bp, bp2, 8);
+ if (cksum_status == INCORRECT) {
+ /*
+ * To quote RFC 4601, "For interoperability
+ * reasons, a message carrying a checksum
+ * calculated over the entire PIM Register
+ * message should also be accepted."
+ */
+ cksum_status = pimv2_check_checksum(ndo, bp, bp2, len);
+ }
+ } else {
+ /*
+ * The checksum covers the entire packet.
+ */
+ cksum_status = pimv2_check_checksum(ndo, bp, bp2, len);
+ }
+ switch (cksum_status) {