synch with van, simplify negative-length (shrinking window) code

SCCS-vsn: sys/netinet/tcp_output.c 7.11

diff --git a/usr/src/sys/netinet/tcp_output.c b/usr/src/sys/netinet/tcp_output.c
index 4d150a4..7ce322d 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        7.10 (Berkeley) %G%
+ *     @(#)tcp_output.c        7.11 (Berkeley) %G%

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


@@ -85,25 +85,18 @@ again:
                /*
                 * If FIN has been sent but not acked,
                 * but we haven't been called to retransmit,
                /*
                 * If FIN has been sent but not acked,
                 * but we haven't been called to retransmit,

-                * len will be -1; transmit if acking, otherwise no need.
-                * Otherwise, window shrank after we sent into it.
-                * If window shrank to 0, cancel pending retransmit
-                * and pull snd_nxt back to (closed) window.
-                * We will enter persist state below.
-                * If the window didn't close completely,
+                * len will be -1.  Otherwise, window shrank
+                * after we sent into it.  If window shrank to 0,
+                * cancel pending retransmit and pull snd_nxt
+                * back to (closed) window.  We will enter persist
+                * state below.  If the window didn't close completely,

                 * just wait for an ACK.
                 */
                 * just wait for an ACK.
                 */

-               if (flags & TH_FIN) {
-                       if (tp->t_flags & TF_ACKNOW)
-                               len = 0;
-                       else
-                               return (0);
-               } else if (win == 0) {
+               len = 0;
+               if (win == 0) {

                        tp->t_timer[TCPT_REXMT] = 0;
                        tp->snd_nxt = tp->snd_una;
                        tp->t_timer[TCPT_REXMT] = 0;
                        tp->snd_nxt = tp->snd_una;

-                       len = 0;
-               } else
-                       return (0);
+               }

        }
        if (len > tp->t_maxseg) {
                len = tp->t_maxseg;
        }
        if (len > tp->t_maxseg) {
                len = tp->t_maxseg;


@@ -159,15 +152,16 @@ again:
        /*
         * Compare available window to amount of window
         * known to peer (as advertised window less
        /*
         * Compare available window to amount of window
         * known to peer (as advertised window less

-        * 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 at least two
+        * max size segments or at least 35% of the maximum possible
+        * window, then want to send a window update to peer.

         */
        if (win > 0) {
                int adv = win - (tp->rcv_adv - tp->rcv_nxt);
 
         */
        if (win > 0) {
                int adv = win - (tp->rcv_adv - tp->rcv_nxt);
 

-               if (100 * adv / so->so_rcv.sb_hiwat >= 35)
+               if (so->so_rcv.sb_cc == 0 && adv >= 2 * tp->t_maxseg)

                        goto send;
                        goto send;

-               if (adv >= 2 * tp->t_maxseg && so->so_rcv.sb_cc == 0)
+               if (100 * adv / so->so_rcv.sb_hiwat >= 35)

                        goto send;
        }
 
                        goto send;
        }