xnu-2422.110.17.tar.gz

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

diff --git a/bsd/netinet/tcp_newreno.c b/bsd/netinet/tcp_newreno.c
index 8d256db71ea6be68fe20fd13e6416dc831461b81..1583112444316f273521485520bd9f79406ec766 100644 (file)
--- a/bsd/netinet/tcp_newreno.c
+++ b/bsd/netinet/tcp_newreno.c
@@ -199,7 +199,7 @@ tcp_newreno_cwnd_init_or_reset(struct tcpcb *tp) {
 void
 tcp_newreno_inseq_ack_rcvd(struct tcpcb *tp, struct tcphdr *th) {
        int acked = 0;
-       acked = th->th_ack - tp->snd_una;
+       acked = BYTES_ACKED(th, tp);
        /*
         * Grow the congestion window, if the
         * connection is cwnd bound.
@@ -233,7 +233,7 @@ tcp_newreno_ack_rcvd(struct tcpcb *tp, struct tcphdr *th) {
        register u_int incr = tp->t_maxseg;
        int acked = 0;
 
-       acked = th->th_ack - tp->snd_una;
+       acked = BYTES_ACKED(th, tp);
        if (tcp_do_rfc3465) {
 
                if (cw >= tp->snd_ssthresh) {
@@ -302,9 +302,13 @@ tcp_newreno_post_fr(struct tcpcb *tp, struct tcphdr *th) {
         * snd_ssthresh outstanding data.  But in case we
         * would be inclined to send a burst, better to do
         * it via the slow start mechanism.
+        *
+        * If the flight size is zero, then make congestion 
+        * window to be worth at least 2 segments to avoid 
+        * delayed acknowledgement (draft-ietf-tcpm-rfc3782-bis-05).
         */
        if (ss < (int32_t)tp->snd_ssthresh)
-               tp->snd_cwnd = ss + tp->t_maxseg;
+               tp->snd_cwnd = max(ss, tp->t_maxseg) + tp->t_maxseg;
        else
                tp->snd_cwnd = tp->snd_ssthresh;
        tp->t_bytes_acked = 0;
@@ -343,11 +347,9 @@ tcp_newreno_after_timeout(struct tcpcb *tp) {
                u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
                if (win < 2)
                        win = 2;
-               tp->snd_cwnd = tp->t_maxseg;
                tp->snd_ssthresh = win * tp->t_maxseg;
-               tp->t_bytes_acked = 0;
-               tp->t_dupacks = 0;
 
+               tp->snd_cwnd = tp->t_maxseg;
                tcp_cc_resize_sndbuf(tp);
        }
 }
@@ -373,6 +375,12 @@ tcp_newreno_after_timeout(struct tcpcb *tp) {
 
 int
 tcp_newreno_delay_ack(struct tcpcb *tp, struct tcphdr *th) {
+       /* If any flags other than TH_ACK is set, set "end-of-write" bit */
+       if ((th->th_flags & ~TH_ACK))
+               tp->t_flagsext |= TF_STREAMEOW;
+       else
+               tp->t_flagsext &= ~(TF_STREAMEOW);
+
        switch (tcp_delack_enabled) {
        case 1:
        case 2: