Phil Karn's retransmit algorithm, using t_rxtcur for current rexmt value;

[unix-history] / usr / src / sys / netinet / tcp_output.c

diff --git a/usr/src/sys/netinet/tcp_output.c b/usr/src/sys/netinet/tcp_output.c
index e21d195..32fdfd3 100644 (file)
--- a/usr/src/sys/netinet/tcp_output.c
+++ b/usr/src/sys/netinet/tcp_output.c
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *

- *     @(#)tcp_output.c        7.8 (Berkeley) %G%
+ *     @(#)tcp_output.c        7.9 (Berkeley) %G%

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -162,9 +162,14 @@ again:
         * next expected input.)  If the difference is 35% or more of the
         * maximum possible window, then want to send a window update to peer.
         */
         * next expected input.)  If the difference is 35% or more of the
         * maximum possible window, then want to send a window update to peer.
         */

-       if (win > 0 &&
-           ((100*(win-(tp->rcv_adv-tp->rcv_nxt))/so->so_rcv.sb_hiwat) >= 35))
-               goto send;
+       if (win > 0) {
+               int adv = win - (tp->rcv_adv - tp->rcv_nxt);
+
+               if (100 * adv / so->so_rcv.sb_hiwat >= 35)
+                       goto send;
+               if (adv >= 2 * tp->t_maxseg && so->so_rcv.sb_cc == 0)
+                       goto send;
+       }

 
        /*
         * TCP window updates are not reliable, rather a polling protocol
 
        /*
         * TCP window updates are not reliable, rather a polling protocol


@@ -261,9 +266,6 @@ send:
                        optlen = sizeof (tcp_initopt);
                        *(u_short *)(opt + 2) = htons(mss);
                }
                        optlen = sizeof (tcp_initopt);
                        *(u_short *)(opt + 2) = htons(mss);
                }

-       } else if (tp->t_tcpopt) {
-               opt = mtod(tp->t_tcpopt, u_char *);
-               optlen = tp->t_tcpopt->m_len;

        }
        if (opt) {
                m0 = m->m_next;
        }
        if (opt) {
                m0 = m->m_next;


@@ -363,11 +365,11 @@ send:
                 */
                if (tp->t_timer[TCPT_REXMT] == 0 &&
                    tp->snd_nxt != tp->snd_una) {
                 */
                if (tp->t_timer[TCPT_REXMT] == 0 &&
                    tp->snd_nxt != tp->snd_una) {

-                       TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
-                         ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
-                         TCPTV_MIN, TCPTV_REXMTMAX);
-                       tp->t_rxtshift = 0;
-                       tp->t_timer[TCPT_PERSIST] = 0;
+                       tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
+                       if (tp->t_timer[TCPT_PERSIST]) {
+                               tp->t_timer[TCPT_PERSIST] = 0;
+                               tp->t_rxtshift = 0;
+                       }

                }
        } else
                if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))
                }
        } else
                if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))