xnu-1228.5.18.tar.gz

[apple/xnu.git] / bsd / netinet / tcp_input.c

diff --git a/bsd/netinet/tcp_input.c b/bsd/netinet/tcp_input.c
index 302ab9431bb26343bbcb76f8af1466c45529c2ef..59dd0cb78b093112f3c68ba1fdf8df27b3898499 100644 (file)
--- a/bsd/netinet/tcp_input.c
+++ b/bsd/netinet/tcp_input.c
@@ -1462,6 +1462,13 @@ findpcb:
                                 * Grow the congestion window, if the
                                 * connection is cwnd bound.
                                 */
+                               if (tp->snd_cwnd < tp->snd_wnd) {
+                                       tp->t_bytes_acked += acked;
+                                       if (tp->t_bytes_acked > tp->snd_cwnd) {
+                                               tp->t_bytes_acked -= tp->snd_cwnd;
+                                               tp->snd_cwnd += tp->t_maxseg;
+                                       }
+                               }
                                sbdrop(&so->so_snd, acked);
                                if (SEQ_GT(tp->snd_una, tp->snd_recover) &&
                                    SEQ_LEQ(th->th_ack, tp->snd_recover))
@@ -2543,44 +2550,29 @@ process_ACK:
                        register u_int cw = tp->snd_cwnd;
                        register u_int incr = tp->t_maxseg;
 
-                       if ((acked > incr) && tcp_do_rfc3465) {
-                               if (cw >= tp->snd_ssthresh) {
-                                       tp->t_bytes_acked += acked;
-                                       if (tp->t_bytes_acked >= cw) {
+                       if (cw >= tp->snd_ssthresh) {
+                               tp->t_bytes_acked += acked;
+                               if (tp->t_bytes_acked >= cw) {
                                        /* Time to increase the window. */
-                                               tp->t_bytes_acked -= cw;
-                                       } else {
-                                       /* No need to increase yet. */
-                                               incr = 0;
-                                       }
+                                       tp->t_bytes_acked -= cw;
                                } else {
-                                       /*
-                                        * If the user explicitly enables RFC3465
-                                        * use 2*SMSS for the "L" param.  Otherwise
-                                        * use the more conservative 1*SMSS.
-                                        *
-                                        * (See RFC 3465 2.3 Choosing the Limit)
-                                        */
-                                       u_int abc_lim;
-
-                                       abc_lim = (tcp_do_rfc3465 == 0) ?
-                                           incr : incr * 2;
-                                       incr = lmin(acked, abc_lim);
+                                       /* No need to increase yet. */
+                                       incr = 0;
                                }
-                       }
-                       else {
+                       } else {
                                /*
-                                * If the window gives us less than ssthresh packets
-                                * in flight, open exponentially (segsz per packet).
-                                * Otherwise open linearly: segsz per window
-                                * (segsz^2 / cwnd per packet).
+                                * If the user explicitly enables RFC3465
+                                * use 2*SMSS for the "L" param.  Otherwise
+                                * use the more conservative 1*SMSS.
+                                *
+                                * (See RFC 3465 2.3 Choosing the Limit)
                                 */
-               
-                                       if (cw >= tp->snd_ssthresh) {
-                                               incr = incr * incr / cw;
-                                       }
-                       }
+                               u_int abc_lim;
 
+                               abc_lim = (tcp_do_rfc3465 == 0) ?
+                                   incr : incr * 2;
+                               incr = min(acked, abc_lim);
+                       }
 
                        tp->snd_cwnd = min(cw+incr, TCP_MAXWIN<<tp->snd_scale);
                }
@@ -3559,6 +3551,9 @@ tcp_mss(tp, offer)
                tp->snd_ssthresh = max(2 * mss, rt->rt_rmx.rmx_ssthresh);
                tcpstat.tcps_usedssthresh++;
        }
+       else
+               tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
+
        lck_mtx_unlock(rt_mtx);
 }