Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 292 insertions, 0 deletions

diff --git a/qemu/slirp/tcp_timer.c b/qemu/slirp/tcp_timer.c
new file mode 100644
index 000000000..6c5bb11cc
--- /dev/null
+++ b/qemu/slirp/tcp_timer.c
@@ -0,0 +1,292 @@
+/*
+ * Copyright (c) 1982, 1986, 1988, 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)tcp_timer.c	8.1 (Berkeley) 6/10/93
+ * tcp_timer.c,v 1.2 1994/08/02 07:49:10 davidg Exp
+ */
+
+#include <slirp.h>
+
+static struct tcpcb *tcp_timers(register struct tcpcb *tp, int timer);
+
+/*
+ * Fast timeout routine for processing delayed acks
+ */
+void
+tcp_fasttimo(Slirp *slirp)
+{
+	register struct socket *so;
+	register struct tcpcb *tp;
+
+	DEBUG_CALL("tcp_fasttimo");
+
+	so = slirp->tcb.so_next;
+	if (so)
+	for (; so != &slirp->tcb; so = so->so_next)
+		if ((tp = (struct tcpcb *)so->so_tcpcb) &&
+		    (tp->t_flags & TF_DELACK)) {
+			tp->t_flags &= ~TF_DELACK;
+			tp->t_flags |= TF_ACKNOW;
+			(void) tcp_output(tp);
+		}
+}
+
+/*
+ * Tcp protocol timeout routine called every 500 ms.
+ * Updates the timers in all active tcb's and
+ * causes finite state machine actions if timers expire.
+ */
+void
+tcp_slowtimo(Slirp *slirp)
+{
+	register struct socket *ip, *ipnxt;
+	register struct tcpcb *tp;
+	register int i;
+
+	DEBUG_CALL("tcp_slowtimo");
+
+	/*
+	 * Search through tcb's and update active timers.
+	 */
+	ip = slirp->tcb.so_next;
+        if (ip == NULL) {
+            return;
+        }
+	for (; ip != &slirp->tcb; ip = ipnxt) {
+		ipnxt = ip->so_next;
+		tp = sototcpcb(ip);
+                if (tp == NULL) {
+                        continue;
+                }
+		for (i = 0; i < TCPT_NTIMERS; i++) {
+			if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
+				tcp_timers(tp,i);
+				if (ipnxt->so_prev != ip)
+					goto tpgone;
+			}
+		}
+		tp->t_idle++;
+		if (tp->t_rtt)
+		   tp->t_rtt++;
+tpgone:
+		;
+	}
+	slirp->tcp_iss += TCP_ISSINCR/PR_SLOWHZ;	/* increment iss */
+	slirp->tcp_now++;				/* for timestamps */
+}
+
+/*
+ * Cancel all timers for TCP tp.
+ */
+void
+tcp_canceltimers(struct tcpcb *tp)
+{
+	register int i;
+
+	for (i = 0; i < TCPT_NTIMERS; i++)
+		tp->t_timer[i] = 0;
+}
+
+const int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
+   { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
+
+/*
+ * TCP timer processing.
+ */
+static struct tcpcb *
+tcp_timers(register struct tcpcb *tp, int timer)
+{
+	register int rexmt;
+
+	DEBUG_CALL("tcp_timers");
+
+	switch (timer) {
+
+	/*
+	 * 2 MSL timeout in shutdown went off.  If we're closed but
+	 * still waiting for peer to close and connection has been idle
+	 * too long, or if 2MSL time is up from TIME_WAIT, delete connection
+	 * control block.  Otherwise, check again in a bit.
+	 */
+	case TCPT_2MSL:
+		if (tp->t_state != TCPS_TIME_WAIT &&
+		    tp->t_idle <= TCP_MAXIDLE)
+			tp->t_timer[TCPT_2MSL] = TCPTV_KEEPINTVL;
+		else
+			tp = tcp_close(tp);
+		break;
+
+	/*
+	 * Retransmission timer went off.  Message has not
+	 * been acked within retransmit interval.  Back off
+	 * to a longer retransmit interval and retransmit one segment.
+	 */
+	case TCPT_REXMT:
+
+		/*
+		 * XXXXX If a packet has timed out, then remove all the queued
+		 * packets for that session.
+		 */
+
+		if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
+			/*
+			 * This is a hack to suit our terminal server here at the uni of canberra
+			 * since they have trouble with zeroes... It usually lets them through
+			 * unharmed, but under some conditions, it'll eat the zeros.  If we
+			 * keep retransmitting it, it'll keep eating the zeroes, so we keep
+			 * retransmitting, and eventually the connection dies...
+			 * (this only happens on incoming data)
+			 *
+			 * So, if we were gonna drop the connection from too many retransmits,
+			 * don't... instead halve the t_maxseg, which might break up the NULLs and
+			 * let them through
+			 *
+			 * *sigh*
+			 */
+
+			tp->t_maxseg >>= 1;
+			if (tp->t_maxseg < 32) {
+				/*
+				 * We tried our best, now the connection must die!
+				 */
+				tp->t_rxtshift = TCP_MAXRXTSHIFT;
+				tp = tcp_drop(tp, tp->t_softerror);
+				/* tp->t_softerror : ETIMEDOUT); */ /* XXX */
+				return (tp); /* XXX */
+			}
+
+			/*
+			 * Set rxtshift to 6, which is still at the maximum
+			 * backoff time
+			 */
+			tp->t_rxtshift = 6;
+		}
+		rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
+		TCPT_RANGESET(tp->t_rxtcur, rexmt,
+		    (short)tp->t_rttmin, TCPTV_REXMTMAX); /* XXX */
+		tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
+		/*
+		 * If losing, let the lower level know and try for
+		 * a better route.  Also, if we backed off this far,
+		 * our srtt estimate is probably bogus.  Clobber it
+		 * so we'll take the next rtt measurement as our srtt;
+		 * move the current srtt into rttvar to keep the current
+		 * retransmit times until then.
+		 */
+		if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
+			tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
+			tp->t_srtt = 0;
+		}
+		tp->snd_nxt = tp->snd_una;
+		/*
+		 * If timing a segment in this window, stop the timer.
+		 */
+		tp->t_rtt = 0;
+		/*
+		 * Close the congestion window down to one segment
+		 * (we'll open it by one segment for each ack we get).
+		 * Since we probably have a window's worth of unacked
+		 * data accumulated, this "slow start" keeps us from
+		 * dumping all that data as back-to-back packets (which
+		 * might overwhelm an intermediate gateway).
+		 *
+		 * There are two phases to the opening: Initially we
+		 * open by one mss on each ack.  This makes the window
+		 * size increase exponentially with time.  If the
+		 * window is larger than the path can handle, this
+		 * exponential growth results in dropped packet(s)
+		 * almost immediately.  To get more time between
+		 * drops but still "push" the network to take advantage
+		 * of improving conditions, we switch from exponential
+		 * to linear window opening at some threshold size.
+		 * For a threshold, we use half the current window
+		 * size, truncated to a multiple of the mss.
+		 *
+		 * (the minimum cwnd that will give us exponential
+		 * growth is 2 mss.  We don't allow the threshold
+		 * to go below this.)
+		 */
+		{
+		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_dupacks = 0;
+		}
+		(void) tcp_output(tp);
+		break;
+
+	/*
+	 * Persistence timer into zero window.
+	 * Force a byte to be output, if possible.
+	 */
+	case TCPT_PERSIST:
+		tcp_setpersist(tp);
+		tp->t_force = 1;
+		(void) tcp_output(tp);
+		tp->t_force = 0;
+		break;
+
+	/*
+	 * Keep-alive timer went off; send something
+	 * or drop connection if idle for too long.
+	 */
+	case TCPT_KEEP:
+		if (tp->t_state < TCPS_ESTABLISHED)
+			goto dropit;
+
+		if ((SO_OPTIONS) && tp->t_state <= TCPS_CLOSE_WAIT) {
+		    	if (tp->t_idle >= TCPTV_KEEP_IDLE + TCP_MAXIDLE)
+				goto dropit;
+			/*
+			 * Send a packet designed to force a response
+			 * if the peer is up and reachable:
+			 * either an ACK if the connection is still alive,
+			 * or an RST if the peer has closed the connection
+			 * due to timeout or reboot.
+			 * Using sequence number tp->snd_una-1
+			 * causes the transmitted zero-length segment
+			 * to lie outside the receive window;
+			 * by the protocol spec, this requires the
+			 * correspondent TCP to respond.
+			 */
+			tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
+			    tp->rcv_nxt, tp->snd_una - 1, 0);
+			tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL;
+		} else
+			tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE;
+		break;
+
+	dropit:
+		tp = tcp_drop(tp, 0);
+		break;
+	}
+
+	return (tp);
+}