10 files changed, 262 insertions(+), 215 deletions(-)

M ip/arp.c
M ip/devip.c
M ip/ethermedium.c
M ip/icmp.c
M ip/icmp6.c
M ip/il.c
M ip/ip.h
M ip/ipifc.c
M ip/tcp.c
M ip/udp.c

@@ 60,56 60,9 @@ arpinit(Fs *f)
 	kproc("rxmitproc", rxmitproc, f->arp);
 }
 
-static Arpent*
-newarp(Arp *arp, uchar *ip, Medium *m)
-{
-	uint t;
-	Block *next, *xp;
-	Arpent *a, *e, *f, **l;
-
-	/* find oldest entry */
-	e = &arp->cache[NCACHE];
-	a = arp->cache;
-	t = a->used;
-	for(f = a; f < e; f++){
-		if(f->used < t){
-			t = f->used;
-			a = f;
-		}
-	}
-
-	/* dump waiting packets */
-	xp = a->hold;
-	a->hold = nil;
-
-	while(xp){
-		next = xp->list;
-		freeblist(xp);
-		xp = next;
-	}
-
-	/* take out of current chain */
-	l = &arp->hash[haship(a->ip)];
-	for(f = *l; f; f = f->hash){
-		if(f == a){
-			*l = a->hash;
-			break;
-		}
-		l = &f->hash;
-	}
-
-	/* insert into new chain */
-	l = &arp->hash[haship(ip)];
-	a->hash = *l;
-	*l = a;
-	memmove(a->ip, ip, sizeof(a->ip));
-	a->used = msec;
-	a->time = 0;
-	a->type = m;
-
-	return a;
-}
-
+/*
+ *  create a new arp entry for an ip address.
+ */
 static Arpent*
 newarp6(Arp *arp, uchar *ip, Ipifc *ifc, int addrxt)
 {


@@ 243,6 196,12 @@ cleanarpent(Arp *arp, Arpent *a)
 	a->ifc = nil;
 }
 
+/*
+ *  fill in the media address if we have it.  Otherwise return an
+ *  Arpent that represents the state of the address resolution FSM
+ *  for ip.  Add the packet to be sent onto the list of packets
+ *  waiting for ip->mac to be resolved.
+ */
 Arpent*
 arpget(Arp *arp, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac)
 {


@@ 265,11 224,7 @@ arpget(Arp *arp, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *mac)
 	}
 
 	if(a == nil){
-		//a = newarp6(arp, ip, ifc, (version != V4));
-		if(version == V4)
-			a = newarp(arp, ip, type);
-		else 
-			a = newarp6(arp, ip, ifc, 1);
+		a = newarp6(arp, ip, ifc, (version != V4));
 		a->state = AWAIT;
 	}
 	a->used = msec;


@@ 300,6 255,9 @@ arprelease(Arp *arp, Arpent*)
 }
 
 /*
+ * Copy out the mac address from the Arpent.  Return the
+ * block waiting to get sent to this mac address.
+ *
  * called with arp locked
  */
 Block*


@@ 348,13 306,19 @@ arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, int refresh)
 		return;
 	}
 
-	if(version == V4){
+	switch(version){
+	case V4:
 		r = v4lookup(fs, ip);
 		v4tov6(v6ip, ip);
 		ip = v6ip;
-	}
-	else
+		break;
+	case V6:
 		r = v6lookup(fs, ip);
+		break;
+	default:
+		panic("arpenter: version %d", version);
+		return;	/* to supress warnings */
+	}
 
 	if(r == nil){
 //		print("arp: no route for entry\n");


@@ 417,12 381,7 @@ arpenter(Fs *fs, int version, uchar *ip, uchar *mac, int n, int refresh)
 	}
 
 	if(refresh == 0){
-		//a = newarp6(arp, ip, ifc, 0);
-		if(version == 4)
-			a = newarp(arp, ip, type);
-		else 
-			a = newarp6(arp, ip, ifc, 0);
-
+		a = newarp6(arp, ip, ifc, 0);
 		a->state = AOK;
 		a->type = type;
 		memmove(a->mac, mac, type->maclen);


@@ 672,7 631,7 @@ rxmitproc(void *v)
 	long wakeupat;
 
 	arp->rxmitp = up;
-	print("arp rxmitproc started\n");
+	//print("arp rxmitproc started\n");
 	if(waserror()){
 		arp->rxmitp = 0;
 		pexit("hangup", 1);

@@ 878,8 878,18 @@ Fsstdconnect(Conv *c, char *argv[], int argc)
 		p = setraddrport(c, argv[1]);
 		if(p != nil)
 			return p;
-		return setladdrport(c, argv[2], 0);
+		p = setladdrport(c, argv[2], 0);
+		if(p != nil)
+			return p;
 	}
+
+	if( (memcmp(c->raddr, v4prefix, IPv4off) == 0 &&
+		memcmp(c->laddr, v4prefix, IPv4off) == 0)
+		|| ipcmp(c->raddr, IPnoaddr) == 0)
+		c->ipversion = V4;
+	else
+		c->ipversion = V6;
+
 	return nil;
 }
 /*


@@ 1308,7 1318,7 @@ Fsrcvpcolx(Fs *f, uchar proto)
  *  called with protocol locked
  */
 Conv*
-Fsnewcall(Conv *c, uchar *raddr, ushort rport, uchar *laddr, ushort lport)
+Fsnewcall(Conv *c, uchar *raddr, ushort rport, uchar *laddr, ushort lport, uchar version)
 {
 	Conv *nc;
 	Conv **l;


@@ 1336,6 1346,8 @@ Fsnewcall(Conv *c, uchar *raddr, ushort rport, uchar *laddr, ushort lport)
 	nc->next = nil;
 	*l = nc;
 	nc->state = Connected;
+	nc->ipversion = version;
+
 	qunlock(c);
 
 	wakeup(&c->listenr);

@@ 252,10 252,16 @@ etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip)
 		/* check for broadcast or multicast */
 		bp = multicastarp(er->f, a, ifc->m, mac);
 		if(bp==nil){
-			if(version == V4) 
+			switch(version){
+			case V4:
 				sendarp(ifc, a);
-			else 
+				break;
+			case V6: 
 				resolveaddr6(ifc, a);
+				break;
+			default:
+				panic("etherbwrite: version %d", version);
+			}
 			return;
 		}
 	}


@@ 283,6 289,8 @@ etherbwrite(Ipifc *ifc, Block *bp, int version, uchar *ip)
 		eh->t[1] = 0xDD;
 		devtab[er->mchan6->type]->bwrite(er->mchan6, bp, 0);
 		break;
+	default:
+		panic("etherbwrite2: version %d", version);
 	}
 	ifc->out++;
 }


@@ 371,14 379,20 @@ etheraddmulti(Ipifc *ifc, uchar *a, uchar *)
 	uchar mac[6];
 	char buf[64];
 	Etherrock *er = ifc->arg;
-	int type;
+	int version;
 
-	type = multicastea(mac, a);
+	version = multicastea(mac, a);
 	sprint(buf, "addmulti %E", mac);
-	if(type == V4) 
+	switch(version){
+	case V4:
 		devtab[er->cchan4->type]->write(er->cchan4, buf, strlen(buf), 0);
-	else if(type == V6) 
+		break;
+	case V6:
 		devtab[er->cchan6->type]->write(er->cchan6, buf, strlen(buf), 0);
+		break;
+	default:
+		panic("etheraddmulti: version %d", version);
+	}
 }
 
 static void


@@ 387,14 401,20 @@ etherremmulti(Ipifc *ifc, uchar *a, uchar *)
 	uchar mac[6];
 	char buf[64];
 	Etherrock *er = ifc->arg;
-	int type;
+	int version;
 
-	type = multicastea(mac, a);
+	version = multicastea(mac, a);
 	sprint(buf, "remmulti %E", mac);
-	if(type == V4) 
+	switch(version){
+	case V4:
 		devtab[er->cchan4->type]->write(er->cchan4, buf, strlen(buf), 0);
-	else if(type == V6) 
+		break;
+	case V6:
 		devtab[er->cchan6->type]->write(er->cchan6, buf, strlen(buf), 0);
+		break;
+	default:
+		panic("etherremmulti: version %d", version);
+	}
 }
 
 /*


@@ 659,7 679,8 @@ multicastea(uchar *ea, uchar *ip)
 
 /*
  *  fill in an arp entry for broadcast or multicast
- *  addresses
+ *  addresses.  Return the first queued packet for the
+ *  IP address.
  */
 static Block*
 multicastarp(Fs *f, Arpent *a, Medium *medium, uchar *mac)

@@ 110,9 110,11 @@ icmpconnect(Conv *c, char **argv, int argc)
 	char *e;
 
 	e = Fsstdconnect(c, argv, argc);
+	if(e != nil)
+		return e;
 	Fsconnected(c, e);
 
-	return e;
+	return nil;
 }
 
 extern int

@@ 196,18 196,6 @@ newIPICMP(int packetlen)
 	return nbp;
 }
 
-
-char*
-icmpconnect6(Conv *c, char **argv, int argc)
-{
-	char *e;
-
-	e = Fsstdconnect(c, argv, argc);
-	Fsconnected(c, e);
-
-	return e;
-}
-
 void
 icmpadvise6(Proto *icmp, Block *bp, char *msg)
 {


@@ 245,7 233,6 @@ icmpkick6(Conv *c)
 
 	if(icb->headers==6) {
 		/* get user specified addresses */
-//print("icmpkick6: headers\n");
 		bp = pullupblock(bp, ICMP_USEAD6);
 		if(bp == nil)
 			return;


@@ 275,7 262,6 @@ icmpkick6(Conv *c)
 	p->vcf[0] = 0x06 << 4;
 	if(p->type <= Maxtype6)	
 		ipriv->out[p->type]++;
-//print("icmpkick6: src %I dst %I\n", p->src, p->dst);
 	ipoput6(c->p->f, bp, 0, c->ttl, c->tos);
 }
 


@@ 893,6 879,7 @@ icmpstats6(Proto *icmp6, char *buf, int len)
 // need to import from icmp.c
 extern int	icmpstate(Conv *c, char *state, int n);
 extern char*	icmpannounce(Conv *c, char **argv, int argc);
+extern char*	icmpconnect(Conv *c, char **argv, int argc);
 extern void	icmpcreate(Conv *c);
 extern void	icmpclose(Conv *c);
 


@@ 904,7 891,7 @@ icmp6init(Fs *fs)
 	icmp6->priv = smalloc(sizeof(Icmppriv6));
 	icmp6->name = "icmpv6";
 	icmp6->kick = icmpkick6;
-	icmp6->connect = icmpconnect6;
+	icmp6->connect = icmpconnect;
 	icmp6->announce = icmpannounce;
 	icmp6->state = icmpstate;
 	icmp6->create = icmpcreate;

@@ 597,7 597,7 @@ iliput(Proto *il, Ipifc*, Block *bp)
 			goto raise;
 		}
 
-		new = Fsnewcall(s, raddr, dp, laddr, sp);
+		new = Fsnewcall(s, raddr, dp, laddr, sp, V4);
 		if(new == nil){
 			qunlock(il);
 			netlog(il->f, Logil, "il: bad newcall %I/%ud->%ud\n", raddr, sp, dp);

@@ 84,6 84,7 @@ struct Conv
 	ushort	rport;			/* remote port number */
 	uint	ttl;			/* max time to live */
 	uint	tos;			/* type of service */
+	uchar	ipversion;		/* IPv4 or IPv6 */
 
 	char	*owner;			/* protections */
 	int	perm;


@@ 360,7 361,7 @@ struct v6params
 
 
 int	Fsconnected(Conv*, char*);
-Conv*	Fsnewcall(Conv*, uchar*, ushort, uchar*, ushort);
+Conv*	Fsnewcall(Conv*, uchar*, ushort, uchar*, ushort, uchar);
 int	Fspcolstats(char*, int);
 int	Fsproto(Fs*, Proto*);
 int	Fsbuiltinproto(Fs*, uchar);

@@ 1278,7 1278,7 @@ findlocalip(Fs *f, uchar *local, uchar *remote)
 	USED(atypel);
 	qlock(f->ipifc);
 	r = v6lookup(f, remote);
- 	version = (memcmp(remote, v4prefix, IPv4off) == 0) ? 4 : 6;
+ 	version = (memcmp(remote, v4prefix, IPv4off) == 0) ? V4 : V6;
 	
 	if(r != nil){
 		ifc = r->ifc;


@@ 1290,7 1290,8 @@ findlocalip(Fs *f, uchar *local, uchar *remote)
 		}
 
 		/* find ifc address closest to the gateway to use */
-		if(version == 4) {
+		switch(version) {
+		case V4:
 			for(lifc = ifc->lifc; lifc; lifc = lifc->next){
 				maskip(gate, lifc->mask, gnet);
 				if(ipcmp(gnet, lifc->net) == 0){


@@ 1298,8 1299,8 @@ findlocalip(Fs *f, uchar *local, uchar *remote)
 					goto out;
 				}
 			}
-		}
-		else {
+			break;
+		case V6:
 			for(lifc = ifc->lifc; lifc; lifc = lifc->next){
 				atypel = v6addrtype(lifc->local);
 				maskip(gate, lifc->mask, gnet);


@@ 1314,14 1315,22 @@ findlocalip(Fs *f, uchar *local, uchar *remote)
 			}
 			if(atype > unspecifiedv6)
 				goto out;
+			break;
+		default:
+			panic("findlocalip: version %d", version);
 		}
 	}
 
-	if(version == 4)
+	switch(version){
+	case V4:
 		findprimaryip(f, local);
-	else
+		break;
+	case V6:
 		findprimaryip6(f, local);
-
+		break;
+	default:
+		panic("findlocalip2: version %d", version);
+	}
 
 out:
 	qunlock(f->ipifc);

@@ 676,15 676,22 @@ tcpmtu(Conv *s)
 {
 	Ipifc *ifc;
 	int mtu;
-	int version = (isv4(s->raddr) && isv4(s->laddr)) ? 4 : 6;
+	uchar version;
 
+	version = s->ipversion;
 	mtu = 0;
 	ifc = findipifc(s->p->f, s->raddr, 0);
 	if(ifc != nil) {
-		if(version == 4)
+		switch(version){
+		case V4:
 			mtu = ifc->maxmtu - ifc->m->hsize - (TCP4_PKT + TCP4_HDRSIZE);
-		else
+			break;
+		case V6:
 			mtu = ifc->maxmtu - ifc->m->hsize - (TCP6_PKT + TCP6_HDRSIZE);
+			break;
+		default:
+			panic("tcpmtu: version %d", version);
+		}
 	}
 
 	if(mtu < 32) {


@@ 698,6 705,9 @@ void
 inittcpctl(Conv *s, int mode)
 {
 	Tcpctl *tcb;
+	Tcp4hdr* h4;
+	Tcp6hdr* h6;
+
 	tcb = (Tcpctl*)s->ptcl;
 
 	memset(tcb, 0, sizeof(Tcpctl));


@@ 719,28 729,32 @@ inittcpctl(Conv *s, int mode)
 	tcb->katimer.arg = s;
 
 	/* create a prototype(pseudo) header */
-	if(mode != TCP_LISTEN)
-	if(ipcmp(s->laddr, IPnoaddr) == 0)
-		findlocalip(s->p->f, s->laddr, s->raddr);
-
-//	if(isv4(s->raddr)) {
-	if(memcmp(s->raddr, v4prefix, IPv4off) == 0 &&
-		memcmp(s->laddr, v4prefix, IPv4off) == 0) {
-		Tcp4hdr* h4 = &tcb->protohdr.tcp4hdr;
-		memset(h4, 0, sizeof(*h4));
-		h4->proto = IP_TCPPROTO;
-		hnputs(h4->tcpsport, s->lport);
-		hnputs(h4->tcpdport, s->rport);
-		v6tov4(h4->tcpsrc, s->laddr);
-		v6tov4(h4->tcpdst, s->raddr);
-	} else {
-		Tcp6hdr* h6 = &tcb->protohdr.tcp6hdr;
-		memset(h6, 0, sizeof(*h6));
-		h6->proto = IP_TCPPROTO;
-		hnputs(h6->tcpsport, s->lport);
-		hnputs(h6->tcpdport, s->rport);
-		ipmove(h6->tcpsrc, s->laddr);
-		ipmove(h6->tcpdst, s->raddr);
+	if(mode != TCP_LISTEN){
+		if(ipcmp(s->laddr, IPnoaddr) == 0)
+			findlocalip(s->p->f, s->laddr, s->raddr);
+
+		switch(s->ipversion){
+		case V4:
+			h4 = &tcb->protohdr.tcp4hdr;
+			memset(h4, 0, sizeof(*h4));
+			h4->proto = IP_TCPPROTO;
+			hnputs(h4->tcpsport, s->lport);
+			hnputs(h4->tcpdport, s->rport);
+			v6tov4(h4->tcpsrc, s->laddr);
+			v6tov4(h4->tcpdst, s->raddr);
+			break;
+		case V6:
+			h6 = &tcb->protohdr.tcp6hdr;
+			memset(h6, 0, sizeof(*h6));
+			h6->proto = IP_TCPPROTO;
+			hnputs(h6->tcpsport, s->lport);
+			hnputs(h6->tcpdport, s->rport);
+			ipmove(h6->tcpsrc, s->laddr);
+			ipmove(h6->tcpdst, s->raddr);
+			break;
+		default:
+			panic("inittcpctl: version %d", s->ipversion);
+		}
 	}
 
 	tcb->mss = tcb->cwind = tcpmtu(s);


@@ 1062,7 1076,7 @@ tcpsndsyn(Tcpctl *tcb)
 }
 
 void
-sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, int version)
+sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, uchar version)
 {
 	Block *hbp;
 	uchar rflags;


@@ 1076,7 1090,8 @@ sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, int vers
 		return;
 
 	/* make pseudo header */
-	if(version == 4) {
+	switch(version) {
+	case V4:
 		memset(&ph4, 0, sizeof(ph4));
 		ph4.vihl = IP_VER4;
 		v6tov4(ph4.tcpsrc, dest);


@@ 1085,8 1100,8 @@ sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, int vers
 		hnputs(ph4.tcplen, TCP4_HDRSIZE);
 		hnputs(ph4.tcpsport, seg->dest);
 		hnputs(ph4.tcpdport, seg->source);
-	}
-	else {
+		break;
+	case V6:
 		memset(&ph6, 0, sizeof(ph6));
 		ph6.vcf[0] = IP_VER6;
 		ipmove(ph6.tcpsrc, dest);


@@ 1095,6 1110,9 @@ sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, int vers
 		hnputs(ph6.ploadlen, TCP6_HDRSIZE);
 		hnputs(ph6.tcpsport, seg->dest);
 		hnputs(ph6.tcpdport, seg->source);
+		break;
+	default:
+		panic("sndrst: version %d", version);
 	}
 
 	tpriv->stats[OutRsts]++;


@@ 1119,17 1137,21 @@ sndrst(Proto *tcp, uchar *source, uchar *dest, ushort length, Tcp *seg, int vers
 	seg->wnd = 0;
 	seg->urg = 0;
 	seg->mss = 0;
-	if(version == 4) {
+	switch(version) {
+	case V4:
 		hbp = htontcp4(seg, nil, &ph4, nil);
 		if(hbp == nil)
 			return;
 		ipoput4(tcp->f, hbp, 0, MAXTTL, DFLTTOS);
-	}
-	else {
+		break;
+	case V6:
 		hbp = htontcp6(seg, nil, &ph6, nil);
 		if(hbp == nil)
 			return;
 		ipoput6(tcp->f, hbp, 0, MAXTTL, DFLTTOS);
+		break;
+	default:
+		panic("sndrst2: version %d", version);
 	}
 }
 


@@ 1148,7 1170,6 @@ tcphangup(Conv *s)
 	if(waserror())
 		return commonerror();
 	if(s->raddr != 0) {
-		int version = isv4(s->raddr) ? 4 : 6;
 		seg.flags = RST | ACK;
 		seg.ack = tcb->rcv.nxt;
 		seg.seq = tcb->snd.ptr;


@@ 1156,15 1177,19 @@ tcphangup(Conv *s)
 		seg.urg = 0;
 		seg.mss = 0;
 		tcb->last_ack = tcb->rcv.nxt;
-		if(version == 4) {
+		switch(s->ipversion) {
+		case V4:
 			tcb->protohdr.tcp4hdr.vihl = IP_VER4;
 			hbp = htontcp4(&seg, nil, &tcb->protohdr.tcp4hdr, tcb);
 			ipoput4(s->p->f, hbp, 0, s->ttl, s->tos);
-		}
-		else {
+			break;
+		case V6:
 			tcb->protohdr.tcp6hdr.vcf[0] = IP_VER6;
 			hbp = htontcp6(&seg, nil, &tcb->protohdr.tcp6hdr, tcb);
 			ipoput6(s->p->f, hbp, 0, s->ttl, s->tos);
+			break;
+		default:
+			panic("tcphangup: version %d", s->ipversion);
 		}
 	}
 	localclose(s, nil);


@@ 1172,14 1197,16 @@ tcphangup(Conv *s)
 	return nil;
 }
 
-Conv*
-tcpincoming(Conv *s, Tcp *segp, uchar *src, uchar *dst)
+static Conv*
+tcpincoming(Conv *s, Tcp *segp, uchar *src, uchar *dst, uchar version)
 {
 	Conv *new;
 	Tcpctl *tcb;
 	Tcppriv *tpriv;
+	Tcp4hdr *h4;
+	Tcp6hdr *h6;
 
-	new = Fsnewcall(s, src, segp->source, dst, segp->dest);
+	new = Fsnewcall(s, src, segp->source, dst, segp->dest, version);
 	if(new == nil)
 		return nil;
 


@@ 1195,23 1222,27 @@ tcpincoming(Conv *s, Tcp *segp, uchar *src, uchar *dst)
 	tcb->rtt_timer.arg = new;
 	tcb->rtt_timer.state = TcptimerOFF;
 
-	if(isv4(src)) {
-		Tcp4hdr *h = &tcb->protohdr.tcp4hdr;
-		memset(h, 0, sizeof(*h));
-		h->proto = IP_TCPPROTO;
-		hnputs(h->tcpsport, new->lport);
-		hnputs(h->tcpdport, new->rport);
-		v6tov4(h->tcpsrc, dst);
-		v6tov4(h->tcpdst, src);
-	}
-	else {
-		Tcp6hdr *h = &tcb->protohdr.tcp6hdr;
-		memset(h, 0, sizeof(*h));
-		h->proto = IP_TCPPROTO;
-		hnputs(h->tcpsport, new->lport);
-		hnputs(h->tcpdport, new->rport);
-		ipmove(h->tcpsrc, dst);
-		ipmove(h->tcpdst, src);
+	switch(version){
+	case V4:
+		h4 = &tcb->protohdr.tcp4hdr;
+		memset(h4, 0, sizeof(*h4));
+		h4->proto = IP_TCPPROTO;
+		hnputs(h4->tcpsport, new->lport);
+		hnputs(h4->tcpdport, new->rport);
+		v6tov4(h4->tcpsrc, dst);
+		v6tov4(h4->tcpdst, src);
+		break;
+	case V6:
+		h6 = &tcb->protohdr.tcp6hdr;
+		memset(h6, 0, sizeof(*h6));
+		h6->proto = IP_TCPPROTO;
+		hnputs(h6->tcpsport, new->lport);
+		hnputs(h6->tcpdport, new->rport);
+		ipmove(h6->tcpsrc, dst);
+		ipmove(h6->tcpdst, src);
+		break;
+	default:
+		panic("tcpincoming: version %d", new->ipversion);
 	}
 
 	tpriv = new->p->priv;


@@ 1442,7 1473,7 @@ tcpiput(Proto *tcp, Ipifc*, Block *bp)
 	Conv *s;
 	Fs *f;
 	Tcppriv *tpriv;
-	int version;
+	uchar version;
 
 	f = tcp->f;
 	tpriv = tcp->priv;


@@ 1453,7 1484,7 @@ tcpiput(Proto *tcp, Ipifc*, Block *bp)
 	h6 = (Tcp6hdr*)(bp->rp);
 
 	if((h4->vihl&0xF0)==IP_VER4) {
-		version = 4;
+		version = V4;
 		length = nhgets(h4->length);
 		v4tov6(dest, h4->tcpdst);
 		v4tov6(source, h4->tcpsrc);


@@ 1491,7 1522,7 @@ tcpiput(Proto *tcp, Ipifc*, Block *bp)
 		int ttl = h6->ttl;
 		int proto = h6->proto;
 
-		version = 6;
+		version = V6;
 		length = nhgets(h6->ploadlen);
 		ipmove(dest, h6->tcpdst);
 		ipmove(source, h6->tcpsrc);


@@ 1554,7 1585,7 @@ reset:
 		if((seg.flags & SYN) == 0 || (seg.flags & ACK) != 0)
 			goto reset;
 
-		s = tcpincoming(s, &seg, source, dest);
+		s = tcpincoming(s, &seg, source, dest, version);
 		if(s == nil)
 			goto reset;
 	}


@@ 1893,18 1924,11 @@ tcpoutput(Conv *s)
 	ulong ssize, dsize, usable, sent;
 	Fs *f;
 	Tcppriv *tpriv;
-	//int version = isv4(s->raddr) ? 4 : 6;
-	int version;
-
-	if( (memcmp(s->raddr, v4prefix, IPv4off) == 0 &&
-		memcmp(s->laddr, v4prefix, IPv4off) == 0)
-		|| ipcmp(s->raddr, IPnoaddr) == 0)
-		version = 4;
-	else
-		version = 6;
+	uchar version;
 
 	f = s->p->f;
 	tpriv = s->p->priv;
+	version = s->ipversion;
 
 	for(msgs = 0; msgs < 100; msgs++) {
 		tcb = (Tcpctl*)s->ptcl;


@@ 2033,21 2057,26 @@ tcpoutput(Conv *s)
 			tcb->snd.nxt = tcb->snd.ptr;
 
 		/* Build header, link data and compute cksum */
-		if(version == 4) {
+		switch(version){
+		case V4:
 			tcb->protohdr.tcp4hdr.vihl = IP_VER4;
 			hbp = htontcp4(&seg, bp, &tcb->protohdr.tcp4hdr, tcb);
 			if(hbp == nil) {
 				freeblist(bp);
 				return;
 			}
-		}
-		else {
+			break;
+		case V6:
 			tcb->protohdr.tcp6hdr.vcf[0] = IP_VER6;
 			hbp = htontcp6(&seg, bp, &tcb->protohdr.tcp6hdr, tcb);
 			if(hbp == nil) {
 				freeblist(bp);
 				return;
 			}
+			break;
+		default:
+			hbp = nil;	/* to suppress a warning */
+			panic("tcpoutput: version %d", version);
 		}
 
 		/* Start the transmission timers if there is new data and we


@@ 2076,10 2105,16 @@ tcpoutput(Conv *s)
 			qlock(s);
 			nexterror();
 		}
-		if(version == 4)
+		switch(version){
+		case V4:
 			ipoput4(f, hbp, 0, s->ttl, s->tos);
-		else
+			break;
+		case V6:
 			ipoput6(f, hbp, 0, s->ttl, s->tos);
+			break;
+		default:
+			panic("tcpoutput2: version %d", version);
+		}
 		qlock(s);
 		poperror();
 	}

@@ 250,18 250,14 @@ udpkick(Conv *c)
 	}
 
 	dlen = blocklen(bp);
-	/* Make space to fit udp & ip header */
-	if(version == 4)
-		bp = padblock(bp, UDP4_IPHDR_SZ+UDP_UDPHDR_SZ);
-	else
-		bp = padblock(bp, UDP6_IPHDR_SZ+UDP_UDPHDR_SZ);
-
-	if(bp == nil)
-		return;
 
 	/* fill in pseudo header and compute checksum */
-	if(version == 4) 
-	{
+	switch(version){
+	case V4:
+		bp = padblock(bp, UDP4_IPHDR_SZ+UDP_UDPHDR_SZ);
+		if(bp == nil)
+			return;
+
 		uh4 = (Udp4hdr *)(bp->rp);
 		ptcllen = dlen + UDP_UDPHDR_SZ;
 		uh4->Unused = 0;


@@ 288,8 284,13 @@ udpkick(Conv *c)
 		       ptclcsum(bp, UDP4_PHDR_OFF, dlen+UDP_UDPHDR_SZ+UDP4_PHDR_SZ));
 		uh4->vihl = IP_VER4;
 		ipoput4(f, bp, 0, c->ttl, c->tos);
-	}
-	else {
+		break;
+
+	case V6:
+		bp = padblock(bp, UDP6_IPHDR_SZ+UDP_UDPHDR_SZ);
+		if(bp == nil)
+			return;
+
 		// using the v6 ip header to create pseudo header 
 		// first then reset it to the normal ip header
 		uh6 = (Udp6hdr *)(bp->rp);


@@ 318,22 319,15 @@ udpkick(Conv *c)
 		uh6->viclfl[0] = IP_VER6;
 		hnputs(uh6->len, ptcllen);
 		uh6->nextheader = IP_UDPPROTO;
-
 		ipoput6(f, bp, 0, c->ttl, c->tos);
+		break;
+
+	default:
+		panic("udpkick: version %d", version);
 	}
 	upriv->ustats.udpOutDatagrams++;
 }
 
-Conv*
-udpincoming(Conv *c, uchar *raddr, ushort rport, uchar *laddr, ushort lport)
-{
-	Conv *new;
-
-	new = Fsnewcall(c, raddr, rport, laddr, lport);
-	if(new == nil)
-		return nil;
-}
-
 void
 udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 {


@@ 347,6 341,7 @@ udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 	Udppriv *upriv;
 	Fs *f;
 	int version;
+	int ottl, oviclfl, olen;
 
 	upriv = udp->priv;
 	f = udp->f;


@@ 357,8 352,8 @@ udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 
 	/* Put back pseudo header for checksum 
 	 * (remember old values for icmpnoconv()) */
-	if(version == 4) {
-		int ottl, olen;
+	switch(version) {
+	case V4:
 		ottl = uh4->Unused;
 		uh4->Unused = 0;
 		len = nhgets(uh4->udplen);


@@ 381,9 376,8 @@ udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 		}
 		uh4->Unused = ottl;
 		hnputs(uh4->udpplen, olen);
-	}
-	else {
-		int ottl, oviclfl, olen;
+		break;
+	case V6:
 		uh6 = (Udp6hdr*)(bp->rp);
 		len = nhgets(uh6->udplen);
 		oviclfl = nhgetl(uh6->viclfl);


@@ 407,6 401,10 @@ udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 		hnputs(uh6->len, olen);
 		uh6->nextheader = IP_UDPPROTO;
 		uh6->hoplimit = ottl;
+		break;
+	default:
+		panic("udpiput: version %d", version);
+		return;	/* to avoid a warning */
 	}
 
 	qlock(udp);


@@ 419,11 417,15 @@ udpiput(Proto *udp, Ipifc *ifc, Block *bp)
 		netlog(f, Logudp, "udp: no conv %I!%d -> %I!%d\n", raddr, rport,
 		       laddr, lport);
 
-		if(version == 4) 
+		switch(version){
+		case V4:
 			icmpnoconv(f, bp);
-		else {
-print("udpiput: no conv %I!%d -> %I!%d\n", raddr, rport, laddr, lport);
+			break;
+		case V6:
 			icmphostunr(f, ifc, bp, icmp6_port_unreach, 0);
+			break;
+		default:
+			panic("udpiput2: version %d", version);
 		}
 
 		freeblist(bp);


@@ 435,12 437,18 @@ print("udpiput: no conv %I!%d -> %I!%d\n", raddr, rport, laddr, lport);
 		if(ucb->headers == 0){
 			/* create a new conversation */
 			if(ipforme(f, laddr) != Runi) {
-				if(version == 4)
+				switch(version){
+				case V4:
 					v4tov6(laddr, ifc->lifc->local);
-				else
+					break;
+				case V6:
 					ipmove(laddr, ifc->lifc->local);
+					break;
+				default:
+					panic("udpiput3: version %d", version);
+				}
 			}
-			c = Fsnewcall(c, raddr, rport, laddr, lport);
+			c = Fsnewcall(c, raddr, rport, laddr, lport, version);
 			if(c == nil){
 				qunlock(udp);
 				freeblist(bp);


@@ 458,10 466,17 @@ print("udpiput: no conv %I!%d -> %I!%d\n", raddr, rport, laddr, lport);
 	 * Trim the packet down to data size
 	 */
 	len -= UDP_UDPHDR_SZ;
-	if(version == 4)
+	switch(version){
+	case V4:
 		bp = trimblock(bp, UDP4_IPHDR_SZ+UDP_UDPHDR_SZ, len);
-	else
+		break;
+	case V6:
 		bp = trimblock(bp, UDP6_IPHDR_SZ+UDP_UDPHDR_SZ, len);
+		break;
+	default:
+		bp = nil;
+		panic("udpiput4: version %d", version);
+	}
 	if(bp == nil){
 		qunlock(c);
 		netlog(f, Logudp, "udp: len err %I.%d -> %I.%d\n", raddr, rport,


@@ 545,17 560,23 @@ udpadvise(Proto *udp, Block *bp, char *msg)
 	h4 = (Udp4hdr*)(bp->rp);
 	version = ((h4->vihl&0xF0)==IP_VER6) ? 6 : 4;
 
-	if(version == 4) {
+	switch(version) {
+	case V4:
 		v4tov6(dest, h4->udpdst);
 		v4tov6(source, h4->udpsrc);
 		psource = nhgets(h4->udpsport);
 		pdest = nhgets(h4->udpdport);
-	} else {
+		break;
+	case V6:
 		h6 = (Udp6hdr*)(bp->rp);
 		ipmove(dest, h6->udpdst);
 		ipmove(source, h6->udpsrc);
 		psource = nhgets(h6->udpsport);
 		pdest = nhgets(h6->udpdport);
+		break;
+	default:
+		panic("udpadvise: version %d", version);
+		return;  /* to avoid a warning */
 	}
 
 	/* Look for a connection */