DLPX-43064 include high-resolution round-trip times in connstat (EP-652)
DLPX-42721 Create inline function for TCP RTO calculation

*** 20,29 ****
--- 20,30 ----
   */
  /*
   * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
   * Copyright 2016 Joyent, Inc.
+  * Copyright (c) 2016 by Delphix. All rights reserved.
   */
  
  #include <sys/types.h>
  #include <sys/stream.h>
  #define _SUN_TPI_VERSION 2
*** 972,984 ****
                                          tcp_wput_data(tcp, NULL, B_FALSE);
                                  }
                                  tcp->tcp_cork = onoff;
                          }
                          break;
!                 case TCP_RTO_INITIAL: {
!                         clock_t rto;
! 
                          if (checkonly || val == 0)
                                  break;
  
                          /*
                           * Sanity checks
--- 973,983 ----
                                          tcp_wput_data(tcp, NULL, B_FALSE);
                                  }
                                  tcp->tcp_cork = onoff;
                          }
                          break;
!                 case TCP_RTO_INITIAL:
                          if (checkonly || val == 0)
                                  break;
  
                          /*
                           * Sanity checks
*** 1004,1022 ****
                           * really affect anything.
                           */
                          if (tcp->tcp_state >= TCPS_SYN_SENT)
                                  break;
  
!                         tcp->tcp_rtt_sa = tcp->tcp_rto_initial << 2;
!                         tcp->tcp_rtt_sd = tcp->tcp_rto_initial >> 1;
!                         rto = (tcp->tcp_rtt_sa >> 3) + tcp->tcp_rtt_sd +
!                             tcps->tcps_rexmit_interval_extra +
!                             (tcp->tcp_rtt_sa >> 5) +
!                             tcps->tcps_conn_grace_period;
!                         TCP_SET_RTO(tcp, rto);
                          break;
-                 }
                  case TCP_RTO_MIN:
                          if (checkonly || val == 0)
                                  break;
  
                          if (val < tcps->tcps_rexmit_interval_min_low ||
--- 1003,1016 ----
                           * really affect anything.
                           */
                          if (tcp->tcp_state >= TCPS_SYN_SENT)
                                  break;
  
!                         tcp->tcp_rtt_sa = MSEC2NSEC(tcp->tcp_rto_initial) << 2;
!                         tcp->tcp_rtt_sd = MSEC2NSEC(tcp->tcp_rto_initial) >> 1;
!                         tcp->tcp_rto = tcp_calculate_rto(tcp, tcps);
                          break;
                  case TCP_RTO_MIN:
                          if (checkonly || val == 0)
                                  break;
  
                          if (val < tcps->tcps_rexmit_interval_min_low ||