dccp: snoop, build system fixes

*** 297,306 ****
--- 297,310 ----
                                  break;
                          case IPPROTO_SCTP:
                                  (void) interpret_sctp(flags,
                                      (struct sctp_hdr *)data, iplen, fraglen);
                                  break;
+                         case IPPROTO_DCCP:
+                                 (void) interpret_dccp(flags,
+                                     (struct dccphdr *)data, iplen, fraglen);
+                                 break;
                          }
                  }
          }
  
          encap_levels--;
*** 475,484 ****
--- 479,492 ----
                              iplen, fraglen);
                          break;
                  case IPPROTO_OSPF:
                          interpret_ospf6(flags, data, iplen, fraglen);
                          break;
+                 case IPPROTO_DCCP:
+                         (void) interpret_dccp(flags, (struct dccphdr *)data,
+                             iplen, fraglen);
+                         break;
                  }
          }
  
          return (iplen);
  }