*/
port0 = ip4_map_port_and_security_check (d0, p0, &error0);
+ /*
+ * Clamp TCP MSS value.
+ */
+ if (ip40->protocol == IP_PROTOCOL_TCP)
+ {
+ tcp_header_t *tcp = ip4_next_header (ip40);
+ if (mm->tcp_mss > 0 && tcp_syn (tcp))
+ {
+ ip_csum_t csum = tcp->checksum;
+ map_mss_clamping (tcp, &csum, mm->tcp_mss);
+ tcp->checksum = ip_csum_fold (csum);
+ }
+ }
+
/* Decrement IPv4 TTL */
ip4_map_decrement_ttl (ip40, &error0);
bool df0 =