2 files changed, 17 insertions(+), 24 deletions(-)

M ip/tcp.c
M pc/devarch.c

@@ 167,7 167,7 @@ struct	Tcp
 	ulong	seq;
 	ulong	ack;
 	uchar	flags;
-	ulong	wnd;
+	ushort	wnd;
 	ushort	urg;
 	ushort	mss;
 	ushort	len;	/* size of data */


@@ 199,32 199,30 @@ struct Tcpctl
 		ulong	una;		/* Unacked data pointer */
 		ulong	nxt;		/* Next sequence expected */
 		ulong	ptr;		/* Data pointer */
-		ulong	wnd;		/* Tcp send window */
+		ushort	wnd;		/* Tcp send window */
 		ulong	urg;		/* Urgent data pointer */
 		ulong	wl2;
 		/* to implement tahoe and reno TCP */
 		ulong	dupacks;	/* number of duplicate acks rcvd */
 		int	recovery;	/* loss recovery flag */
 		ulong	rxt;		/* right window marker for recovery */
-		int	scale;		/* how much to right shift window in xmitted packets */
 	} snd;
 	struct {
 		ulong	nxt;		/* Receive pointer to next uchar slot */
-		ulong	wnd;		/* Receive window incoming */
+		ushort	wnd;		/* Receive window incoming */
 		ulong	urg;		/* Urgent pointer */
 		ulong	lastacked;	/* Last ack sent */
 		int	blocked;
 		int	una;		/* unacked data segs */
-		int	scale;		/* how much to left shift window in rcved packets */
 	} rcv;
 	ulong	iss;			/* Initial sequence number */
-	ulong	cwind;			/* Congestion window */
+	ushort	cwind;			/* Congestion window */
 	ushort	ssthresh;		/* Slow start threshold */
 	int	resent;			/* Bytes just resent */
 	int	irs;			/* Initial received squence */
 	ushort	mss;			/* Mean segment size */
 	int	rerecv;			/* Overlap of data rerecevived */
-	ulong	window;			/* Recevive window */
+	ushort	window;			/* Recevive window */
 	uchar	backoff;		/* Exponential backoff counter */
 	int	backedoff;		/* ms we've backed off for rexmits */
 	uchar	flags;			/* State flags */


@@ 364,7 362,7 @@ void	procsyn(Conv*, Tcp*);
 void	tcpiput(Proto*, Ipifc*, Block*);
 void	tcpoutput(Conv*);
 int	tcptrim(Tcpctl*, Tcp*, Block**, ushort*);
-void	tcpstart(Conv*, int, ulong);
+void	tcpstart(Conv*, int, ushort);
 void	tcptimeout(void*);
 void	tcpsndsyn(Tcpctl*);
 void	tcprcvwin(Conv*);


@@ 442,7 440,7 @@ tcpstate(Conv *c, char *state, int n)
 	s = (Tcpctl*)(c->ptcl);
 
 	return snprint(state, n,
-		"%s srtt %d mdev %d cwin %lud swin %lud rwin %lud timer.start %d timer.count %d rerecv %d\n",
+		"%s srtt %d mdev %d cwin %d swin %d rwin %d timer.start %d timer.count %d rerecv %d\n",
 		tcpstates[s->state], s->srtt, s->mdev,
 		s->cwind, s->snd.wnd, s->rcv.wnd,
 		s->timer.start, s->timer.count, s->rerecv);


@@ 556,7 554,7 @@ tcprcvwin(Conv *s)				/* Call with tcb locked */
 	Tcpctl *tcb;
 
 	tcb = (Tcpctl*)s->ptcl;
-	w = tcb->window - qlen(s->rq);
+	w = QMAX - qlen(s->rq);
 	if(w < 0)
 		w = 0;
 	tcb->rcv.wnd = w;


@@ 828,7 826,7 @@ inittcpctl(Conv *s, int mode)
  *  called with s qlocked
  */
 void
-tcpstart(Conv *s, int mode, ulong window)
+tcpstart(Conv *s, int mode, ushort window)
 {
 	Tcpctl *tcb;
 	Tcppriv *tpriv;


@@ 852,8 850,6 @@ tcpstart(Conv *s, int mode, ulong window)
 	inittcpctl(s, mode);
 	tcb->window = window;
 	tcb->rcv.wnd = window;
-	tcb->rcv.scale = 0;
-	tcb->snd.scale = 0;
 
 	iphtadd(&tpriv->ht, s);
 	switch(mode) {


@@ 934,7 930,7 @@ htontcp6(Tcp *tcph, Block *data, Tcp6hdr *ph, Tcpctl *tcb)
 	hnputl(h->tcpseq, tcph->seq);
 	hnputl(h->tcpack, tcph->ack);
 	hnputs(h->tcpflag, (hdrlen<<10) | tcph->flags);
-	hnputs(h->tcpwin, tcph->wnd>>tcb->snd.scale);
+	hnputs(h->tcpwin, tcph->wnd);
 	hnputs(h->tcpurg, tcph->urg);
 
 	if(tcph->mss != 0){


@@ 993,7 989,7 @@ htontcp4(Tcp *tcph, Block *data, Tcp4hdr *ph, Tcpctl *tcb)
 	hnputl(h->tcpseq, tcph->seq);
 	hnputl(h->tcpack, tcph->ack);
 	hnputs(h->tcpflag, (hdrlen<<10) | tcph->flags);
-	hnputs(h->tcpwin, tcph->wnd>>tcb->snd.scale);
+	hnputs(h->tcpwin, tcph->wnd);
 	hnputs(h->tcpurg, tcph->urg);
 
 	if(tcph->mss != 0){


@@ 1668,8 1664,7 @@ update(Conv *s, Tcp *seg)
 {
 	int rtt, delta;
 	Tcpctl *tcb;
-	ulong acked;
-	ulong expand;
+	ushort acked, expand;
 	Tcppriv *tpriv;
 
 	tpriv = s->p->priv;


@@ 1757,7 1752,7 @@ update(Conv *s, Tcp *seg)
 			expand = ((int)tcb->mss * tcb->mss) / tcb->cwind;
 
 		if(tcb->cwind + expand < tcb->cwind)
-			expand = tcb->snd.wnd - tcb->cwind;
+			expand = 65535 - tcb->cwind;
 		if(tcb->cwind + expand > tcb->snd.wnd)
 			expand = tcb->snd.wnd - tcb->cwind;
 		if(expand != 0)


@@ 1967,9 1962,6 @@ reset:
 	qlock(s);
 	qunlock(tcp);
 
-	/* scale up window */
-	seg.wnd <<= tcb->rcv.scale;
-
 	if(tcb->kacounter > 0)
 		tcb->kacounter = MAXBACKMS / (tcb->katimer.start*MSPTICK);
 	if(tcb->kacounter < 3)


@@ 2348,7 2340,7 @@ tcpoutput(Conv *s)
 		}
 		ssize = sndcnt-sent;
 		if(ssize && usable < 2)
-			netlog(s->p->f, Logtcp, "throttled snd.wnd %lud cwind %lud\n",
+			netlog(s->p->f, Logtcp, "throttled snd.wnd 0x%ux cwind 0x%ux\n",
 				tcb->snd.wnd, tcb->cwind);
 		if(usable < ssize)
 			ssize = usable;

@@ 391,7 391,8 @@ archread(Chan *c, void *a, long n, vlong offset)
 		break;
 	}
 
-	if((buf = malloc(n)) == nil)
+	/* allocate a buffer to avoid page faults in the loop */
+	if((buf = malloc(n+1)) == nil)	/* +1 for the NUL */
 		error(Enomem);
 	p = buf;
 	n = n/Linelen;


@@ 403,7 404,7 @@ archread(Chan *c, void *a, long n, vlong offset)
 			continue;
 		if(strcmp(m->tag, "dummy") == 0)
 			break;
-		sprint(p, "%8lux %8lux %-12.12s\n", m->start, m->end-1, m->tag);
+		snprint(p, Linelen+1, "%8lux %8lux %-12.12s\n", m->start, m->end-1, m->tag);
 		p += Linelen;
 		n--;
 	}