+/*
+ * Set a new snapshot end to the minimum of the existing snapshot end
+ * and the new snapshot end.
+ */
+int
+nd_push_snapend(netdissect_options *ndo, const u_char *new_snapend)
+{
+ struct netdissect_saved_packet_info *ndspi;
+
+ ndspi = (struct netdissect_saved_packet_info *)malloc(sizeof(struct netdissect_saved_packet_info));
+ if (ndspi == NULL)
+ return (0); /* fail */
+ ndspi->ndspi_buffer = NULL; /* no new buffer */
+ ndspi->ndspi_packetp = ndo->ndo_packetp;
+ ndspi->ndspi_snapend = ndo->ndo_snapend;
+ ndspi->ndspi_prev = ndo->ndo_packet_info_stack;
+
+ /* No new packet pointer, either */
+ if (new_snapend < ndo->ndo_snapend)
+ ndo->ndo_snapend = new_snapend;
+ ndo->ndo_packet_info_stack = ndspi;
+
+ return (1); /* success */
+}
+
+/*
+ * Change an already-pushed snapshot end. This may increase the
+ * snapshot end, as it may be used, for example, for a Jumbo Payload
+ * option in IPv6. It must not increase it past the snapshot length
+ * atop which the current one was pushed, however.
+ */
+void
+nd_change_snapend(netdissect_options *ndo, const u_char *new_snapend)
+{
+ struct netdissect_saved_packet_info *ndspi;
+
+ ndspi = ndo->ndo_packet_info_stack;
+ if (ndspi->ndspi_prev != NULL) {
+ if (new_snapend <= ndspi->ndspi_prev->ndspi_snapend)
+ ndo->ndo_snapend = new_snapend;
+ } else {
+ if (new_snapend < ndo->ndo_snapend)
+ ndo->ndo_snapend = new_snapend;
+ }
+}
+