Fix a logical error in T/TCP: when we actively open a connection, we

have to decide whether to send a CC or CCnew option in our SYN segment
depending on the contents of our TAO cache.  This decision has to be
made once when the connection starts.  The earlier code delayed this
decision until the segment was assembled in tcp_output() and
retransmitted SYN segments could have different CC options.

Reviewed by:	Richard Stevens, davidg, wollman

1 files changed, 20 insertions, 1 deletions

diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index ab4c5c9..1b05f16 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	From: @(#)tcp_usrreq.c	8.2 (Berkeley) 1/3/94
- *	$Id: tcp_usrreq.c,v 1.16 1995/09/13 17:54:03 wollman Exp $
+ *	$Id: tcp_usrreq.c,v 1.17 1995/10/29 21:30:25 olah Exp $
  */
 
 #include <sys/param.h>
@@ -407,6 +407,8 @@ tcp_connect(tp, nam)
 	struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *);
 	struct sockaddr_in *ifaddr;
 	int error;
+	struct rmxp_tao *taop;
+	struct rmxp_tao tao_noncached;
 
 	if (inp->inp_lport == 0) {
 		error = in_pcbbind(inp, NULL);
@@ -459,7 +461,24 @@ tcp_connect(tp, nam)
 	tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
 	tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2;
 	tcp_sendseqinit(tp);
+
+	/*
+	 * Generate a CC value for this connection and
+	 * check whether CC or CCnew should be used.
+	 */
+	if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
+		taop = &tao_noncached;
+		bzero(taop, sizeof(*taop));
+	}
+
 	tp->cc_send = CC_INC(tcp_ccgen);
+	if (taop->tao_ccsent != 0 &&
+	    CC_GEQ(tp->cc_send, taop->tao_ccsent)) {
+		taop->tao_ccsent = tp->cc_send;
+	} else {
+		taop->tao_ccsent = 0;
+		tp->t_flags |= TF_SENDCCNEW;
+	}
 
 	return 0;
 }