xnu-1228.5.20.tar.gz

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

diff --git a/bsd/netinet/tcp_output.c b/bsd/netinet/tcp_output.c
index 250d4a2d66ef6c9582fef571065d6718a3cdf53c..ca32f6b401d57c82d02fe25c1b57e0d80fbe8bea 100644 (file)
--- a/bsd/netinet/tcp_output.c
+++ b/bsd/netinet/tcp_output.c
@@ -167,8 +167,10 @@ extern int ipsec_bypass;
 
 extern int slowlink_wsize;     /* window correction for slow links */
 extern u_long  route_generation;
 
 extern int slowlink_wsize;     /* window correction for slow links */
 extern u_long  route_generation;

+#if IPFIREWALL

 extern int fw_enable;          /* firewall check for packet chaining */
 extern int fw_bypass;          /* firewall check: disable packet chaining if there is rules */
 extern int fw_enable;          /* firewall check for packet chaining */
 extern int fw_bypass;          /* firewall check: disable packet chaining if there is rules */

+#endif /* IPFIREWALL */

 
 extern vm_size_t       so_cache_zone_element_size;
 
 
 extern vm_size_t       so_cache_zone_element_size;
 


@@ -677,10 +679,19 @@ after_sack_rexmit:
                long adv = lmin(recwin, (long)TCP_MAXWIN << tp->rcv_scale) -
                        (tp->rcv_adv - tp->rcv_nxt);
 
                long adv = lmin(recwin, (long)TCP_MAXWIN << tp->rcv_scale) -
                        (tp->rcv_adv - tp->rcv_nxt);
 

-               if (adv >= (long) (2 * tp->t_maxseg))
-                       goto send;
-               if (2 * adv >= (long) so->so_rcv.sb_hiwat)
-                       goto send;
+               if (adv >= (long) (2 * tp->t_maxseg)) {
+                       
+                       /* 
+                        * Update only if the resulting scaled value of the window changed, or
+                        * if there is a change in the sequence since the last ack.
+                        * This avoids what appears as dupe ACKS (see rdar://5640997)
+                        */
+
+                       if ((tp->last_ack_sent != tp->rcv_nxt) || (((recwin + adv) >> tp->rcv_scale) > recwin)) 
+                               goto send;
+               }
+               if (2 * adv >= (long) so->so_rcv.sb_hiwat) 
+                               goto send;

        }
 
        /*
        }
 
        /*


@@ -706,7 +717,7 @@ after_sack_rexmit:
         * after the retransmission timer has been turned off.  Make sure
         * that the retransmission timer is set.
         */
         * after the retransmission timer has been turned off.  Make sure
         * that the retransmission timer is set.
         */

-       if (tp->sack_enable && SEQ_GT(tp->snd_max, tp->snd_una) &&
+       if (tp->sack_enable && (tp->t_state >= TCPS_ESTABLISHED) && SEQ_GT(tp->snd_max, tp->snd_una) &&

                tp->t_timer[TCPT_REXMT] == 0 &&
            tp->t_timer[TCPT_PERSIST] == 0) {
                        tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
                tp->t_timer[TCPT_REXMT] == 0 &&
            tp->t_timer[TCPT_PERSIST] == 0) {
                        tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;


@@ -1239,6 +1250,8 @@ send:
                tp->sackhint.sack_bytes_rexmit += len;
        }
        th->th_ack = htonl(tp->rcv_nxt);
                tp->sackhint.sack_bytes_rexmit += len;
        }
        th->th_ack = htonl(tp->rcv_nxt);

+       tp->last_ack_sent = tp->rcv_nxt;
+

        if (optlen) {
                bcopy(opt, th + 1, optlen);
                th->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
        if (optlen) {
                bcopy(opt, th + 1, optlen);
                th->th_off = (sizeof (struct tcphdr) + optlen) >> 2;


@@ -1623,6 +1636,11 @@ tcp_ip_output(struct socket *so, struct tcpcb *tp, struct mbuf *pkt,
        boolean_t chain;
        boolean_t unlocked = FALSE;
 
        boolean_t chain;
        boolean_t unlocked = FALSE;
 

+       /* Make sure ACK/DELACK conditions are cleared before
+        * we unlock the socket.
+        */
+
+       tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);

        /*
         * If allowed, unlock TCP socket while in IP 
         * but only if the connection is established and
        /*
         * If allowed, unlock TCP socket while in IP 
         * but only if the connection is established and


@@ -1642,11 +1660,15 @@ tcp_ip_output(struct socket *so, struct tcpcb *tp, struct mbuf *pkt,
         * - there is a non default rule set for the firewall
         */
 
         * - there is a non default rule set for the firewall
         */
 

-       chain = tcp_packet_chaining > 1 &&
+       chain = tcp_packet_chaining > 1

 #if IPSEC
 #if IPSEC

-               ipsec_bypass &&
+               && ipsec_bypass
+#endif
+#if IPFIREWALL
+               && (fw_enable == 0 || fw_bypass)

 #endif
 #endif

-               (fw_enable == 0 || fw_bypass);
+               ; // I'm important, not extraneous
+

 
        while (pkt != NULL) {
                struct mbuf *npkt = pkt->m_nextpkt;
 
        while (pkt != NULL) {
                struct mbuf *npkt = pkt->m_nextpkt;