dccp: snoop, build system fixes

*** 234,243 ****
--- 234,247 ----
  
                          case IPPROTO_UDP:
                                  (void) interpret_udp(flags,
                                      (struct udphdr *)data, new_iplen, fraglen);
                                  break;
+                         case IPPROTO_DCCP:
+                                 (void) interpret_dccp(flags,
+                                     (struct dccphdr *)data, new_iplen, fraglen);
+                                 break;
                          /* default case is to not print anything else */
                  }
  
          return (ahlen);
  }