From 8df99f1ca907699bc9dde35b90f191e20d619468 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 24 Oct 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-10-24

---
 port/devenv.c  |   3 +
 port/devip.c   | 154 +++++++++++++++++++++++++------------------------
 port/ipdat.h   |   3 +
 port/proc.c    |   8 +--
 port/segment.c |  15 ++---
 port/stil.c    |  30 ++++++++--
 6 files changed, 122 insertions(+), 91 deletions(-)

diff --git a/port/devenv.c b/port/devenv.c
index 9d215c8f14b72d1385f455b9a77fb5e23846d247..d9322d89911dd77f873d9d1bedb11b33bb523517 100644
--- a/port/devenv.c
+++ b/port/devenv.c
@@ -391,6 +391,8 @@ evfree(Envval *ev)
 
 	if(ev->prev)
 		ev->prev->next = ev->next;
+	else
+		panic("evfree");
 	if(ev->next)
 		ev->next->prev = ev->prev;
 	n = (ev->len + ALIGN - 1) & ~(ALIGN - 1);
@@ -399,6 +401,7 @@ evfree(Envval *ev)
 	if(n > EVFREE)
 		n = EVFREE;
 	ev->next = envalloc.free[n];
+	ev->prev = 0;
 	envalloc.free[n] = ev;
 }
 
diff --git a/port/devip.c b/port/devip.c
index 1918b6c0f8ac117914fe03becf43f3bc2300287b..9aa9b7e19a2cd79a730c799b4d15ce3ba39323f8 100644
--- a/port/devip.c
+++ b/port/devip.c
@@ -181,7 +181,7 @@ ipopen(Chan *c, int omode)
 			error(Eprotonosup);
 
 		if(cp->backlog == 0)
-			cp->backlog = 1;
+			cp->backlog = 3;
 
 		streamopen(c, &ipinfo);
 		if(c->stream->devq->next->info != cp->stproto)
@@ -226,7 +226,7 @@ ipclonecon(Chan *c)
 	base = ipconv[c->dev];
 	etab = &base[conf.ip];
 	for(new = base; new < etab; new++) {
-		new = ipincoming(c->dev);
+		new = ipincoming(base);
 		if(new == 0)
 			error(Enodev);
 
@@ -243,11 +243,10 @@ ipclonecon(Chan *c)
 }
 
 Ipconv *
-ipincoming(int dev)
+ipincoming(Ipconv *base)
 {
-	Ipconv *base, *new, *etab;
+	Ipconv *new, *etab;
 
-	base = ipconv[dev];
 	etab = &base[conf.ip];
 	for(new = base; new < etab; new++) {
 		if(new->ref == 0 && canqlock(new)) {
@@ -335,86 +334,93 @@ long
 ipwrite(Chan *c, char *a, long n, ulong offset)
 {
 	int 	m, backlog, type;
-	char 	*field[5], buf[256];
-	Ipconv  *cp;
+	char 	*field[5], *ctlarg[5], buf[256];
 	Port	port, base;
+	Ipconv  *cp;
 
 	type = STREAMTYPE(c->qid.path);
 	if (type == Sdataqid)
 		return streamwrite(c, a, n, 0); 
 
-	if (type == Sctlqid) {
-		cp = &ipconv[c->dev][STREAMID(c->qid.path)];
-
-		strncpy(buf, a, sizeof buf);
-		m = getfields(buf, field, 5, ' ');
-
-		if(strcmp(field[0], "connect") == 0) {
-			if((cp->stproto == &tcpinfo && cp->tcpctl.state != CLOSED) ||
-			   (cp->stproto == &ilinfo && cp->ilctl.state != Ilclosed))
-					error(Edevbusy);
-
-			if(m != 2)
-				error(Ebadarg);
-
-			switch(getfields(field[1], field, 5, '!')) {
-			default:
-				error(Ebadarg);
-			case 2:
-				base = PORTALLOC;
-				break;
-			case 3:
-				if(strcmp(field[2], "r") != 0)
-					error(Eperm);
-				base = PRIVPORTALLOC;
-				break;
-			}
-			cp->dst = ipparse(field[0]);
-			cp->pdst = atoi(field[1]);
+	if (type != Sctlqid)
+		error(Eperm);
 
-			/* If we have no local port assign one */
-			qlock(&ipalloc);
-			if(cp->psrc == 0)
-				cp->psrc = nextport(ipconv[c->dev], base);
-			qunlock(&ipalloc);
+	cp = &ipconv[c->dev][STREAMID(c->qid.path)];
 
+	m = n;
+	if(m > sizeof(buf)-1)
+		m = sizeof(buf)-1;
+	strncpy(buf, a, m);
+	buf[m] = '\0';
+
+	m = getfields(buf, field, 5, ' ');
+	if(m < 1)
+		errors("bad ip control");
+
+	if(strcmp(field[0], "connect") == 0) {
+		if((cp->stproto == &tcpinfo && cp->tcpctl.state != CLOSED) ||
+		   (cp->stproto == &ilinfo && cp->ilctl.state != Ilclosed))
+				error(Edevbusy);
+
+		if(m != 2)
+			error(Ebadarg);
+
+		switch(m = getfields(field[1], ctlarg, 5, '!')) {
+		default:
+			error(Ebadarg);
+		case 2:
+			base = PORTALLOC;
+			break;
+		case 3:
+			if(strcmp(ctlarg[2], "r") != 0)
+				error(Eperm);
+			base = PRIVPORTALLOC;
+			break;
 		}
-		else if(strcmp(field[0], "announce") == 0 ||
-			strcmp(field[0], "reserve") == 0) {
-			if((cp->stproto == &tcpinfo && cp->tcpctl.state != CLOSED) ||
-			   (cp->stproto == &ilinfo && cp->ilctl.state != Ilclosed))
-					error(Edevbusy);
-
-			if(m != 2)
-				error(Ebadarg);
-			port = atoi(field[1]);
-
-			qlock(&ipalloc);
-			if(portused(ipconv[c->dev], port)) {
-				qunlock(&ipalloc);	
-				error(Einuse);
-			}
-			cp->psrc = port;
-			cp->ptype = *field[0];
-			qunlock(&ipalloc);
-		}
-		else if(strcmp(field[0], "backlog") == 0) {
-			if(m != 2)
-				error(Ebadarg);
-			backlog = atoi(field[1]);
-			if(backlog == 0)
-				error(Ebadarg);
-			if(backlog > 5)
-				backlog = 5;
-			cp->backlog = backlog;
-		}
-		else
-			return streamwrite(c, a, n, 0);
+		cp->dst = ipparse(ctlarg[0]);
+		cp->pdst = atoi(ctlarg[1]);
+
+		/* If we have no local port assign one */
+		qlock(&ipalloc);
+		if(cp->psrc == 0)
+			cp->psrc = nextport(ipconv[c->dev], base);
+		qunlock(&ipalloc);
 
-		return n;
 	}
+	else if(strcmp(field[0], "announce") == 0 ||
+		strcmp(field[0], "reserve") == 0) {
+		if((cp->stproto == &tcpinfo && cp->tcpctl.state != CLOSED) ||
+		   (cp->stproto == &ilinfo && cp->ilctl.state != Ilclosed))
+				error(Edevbusy);
 
-	error(Eperm);
+		if(m != 2)
+			error(Ebadarg);
+
+		port = atoi(field[1]);
+
+		qlock(&ipalloc);
+		if(portused(ipconv[c->dev], port)) {
+			qunlock(&ipalloc);	
+			error(Einuse);
+		}
+		cp->psrc = port;
+		cp->ptype = *field[0];
+		qunlock(&ipalloc);
+	}
+	else if(strcmp(field[0], "backlog") == 0) {
+		if(m != 2)
+			error(Ebadarg);
+		backlog = atoi(field[1]);
+		if(backlog == 0)
+			error(Ebadarg);
+		if(backlog > 5)
+			backlog = 5;
+		cp->backlog = backlog;
+	}
+	else
+		return streamwrite(c, a, n, 0);
+
+	return n;
 }
 
 
@@ -690,7 +696,7 @@ iplisten(Chan *c, Ipconv *s, Ipconv *base)
 				pushq(c->stream, new->stproto);
 				new->ref--;
 				qunlock(&s->listenq);
-
+print("ip listener!\n");
 				return;
 			}
 		}
diff --git a/port/ipdat.h b/port/ipdat.h
index 8b9195e80e1c5a781d8a14ddc49655ea18bbc8b6..a6b3919739535a1b4a0554b0e978d5d0725d83b9 100644
--- a/port/ipdat.h
+++ b/port/ipdat.h
@@ -46,6 +46,7 @@ struct Udphdr
 	uchar	d[6];		/* Ethernet destination */
 	uchar	s[6];		/* Ethernet source */
 	uchar	type[2];	/* Ethernet packet type */
+
 	uchar	vihl;		/* Version and header length */
 	uchar	tos;		/* Type of service */
 	uchar	length[2];	/* packet length */
@@ -72,6 +73,7 @@ struct Ilhdr
 	uchar	d[6];		/* Ethernet destination */
 	uchar	s[6];		/* Ethernet source */
 	uchar	type[2];	/* Ethernet packet type */
+
 	uchar	vihl;		/* Version and header length */
 	uchar	tos;		/* Type of service */
 	uchar	length[2];	/* packet length */
@@ -265,6 +267,7 @@ struct Ipconv
 	Ipaddr	dst;			/* Destination from connect */
 	Port	psrc;			/* Source port */
 	Port	pdst;			/* Destination port */
+	char	ptype;			/* Port type */
 
 	Ipifc	*ipinterface;		/* Ip protocol interface */
 	Queue	*readq;			/* Pointer to upstream read q */
diff --git a/port/proc.c b/port/proc.c
index 2948abd63b9e996c69a779eef5e49311a69612d4..502d82ad29dec5180d9ce90cfafa82f09f7c6d8c 100644
--- a/port/proc.c
+++ b/port/proc.c
@@ -521,6 +521,10 @@ pexit(char *exitstr, int freemem)
 
 	if(c->fgrp)
 		closefgrp(c->fgrp);
+	closepgrp(c->pgrp);
+	close(u->dot);
+	if(c->egrp)
+		closeegrp(c->egrp);
 
 	if(c->kp == 0) {
 		wq = newwaitq();
@@ -566,10 +570,6 @@ pexit(char *exitstr, int freemem)
 			*s = 0;
 			putseg(os);
 		}
-	closepgrp(c->pgrp);
-	if(c->egrp)
-		closeegrp(c->egrp);
-	close(u->dot);
 
 	lock(&c->exl);		/* Prevent my children from leaving waits */
 	c->pid = 0;
diff --git a/port/segment.c b/port/segment.c
index 7ab3e89708ef2894df66271cafb7a1fb0876420b..7e4bcb609ae0ec2a23316c3e1de4a09277a6f9f5 100644
--- a/port/segment.c
+++ b/port/segment.c
@@ -265,21 +265,22 @@ imagereclaim(void)
 	if(!canqlock(&ireclaim))	/* Somebody is already cleaning the page cache */
 		return;
 
-	lock(&palloc);
-	for(p = palloc.head; p; p = p->next) {
-		if(p->image == 0)
-			continue;
+	for(;;) {
+		lock(&palloc);
+		for(p = palloc.head; p; p = p->next)
+			if(p->image && p->ref == 0 && p->image != &swapimage)
+				break;
 
 		unlock(&palloc);
+		if(p == 0)
+			break;
+
 		lockpage(p);
 		if(p->ref == 0 && p->image != &swapimage)
 			uncachepage(p);
 		unlockpage(p);
-		lock(&palloc);
 	}
 
-	unlock(&palloc);
-
 	qunlock(&ireclaim);
 }
 
diff --git a/port/stil.c b/port/stil.c
index 4976d5a7fbf611c23dcd212eac3f51c003292d32..6691c7156d8a3a6bdafd4d8cf520d9b38238a875 100644
--- a/port/stil.c
+++ b/port/stil.c
@@ -187,8 +187,9 @@ ilrcvmsg(Ipconv *ipc, Block *bp)
 	int plen;
 	Ipconv *s, *etab, *new;
 	short sp, dp;
+	Ipaddr dst;
 
-	ih = (Ilhdr *)bp;
+	ih = (Ilhdr *)bp->rptr;
 
 	plen = blen(bp);
 	if(plen < IL_EHSIZE+IL_HDRSIZE)
@@ -201,17 +202,26 @@ ilrcvmsg(Ipconv *ipc, Block *bp)
 
 	sp = nhgets(ih->ildst);
 	dp = nhgets(ih->ilsrc);
+	dst = nhgetl(ih->src);
+
+print("got packet from %d.%d.%d.%d %d %d\n", fmtaddr(dst), sp, dp);
+
 	etab = &ipc[conf.ip];
 	for(s = ipc; s < etab; s++) {
-		if(s->psrc == sp && s->pdst == dp) {
+		if(s->psrc == sp && s->pdst == dp && s->dst == dst) {
 			ilprocess(s, ih, bp);
 			return;
 		}
 			
 	}
 
+	if(s->curlog > s->backlog) {
+print("Backlog\n");
+		goto reset;
+	}
+
 	for(s = ipc; s < etab; s++) {
-		if(s->ilctl.state == Illistening && s->psrc == 0) {
+		if(s->ilctl.state == Illistening && s->pdst == 0) {
 			/* Do the listener stuff */
 			new = ipincoming(ipc);
 			if(new == 0) 
@@ -222,6 +232,7 @@ ilrcvmsg(Ipconv *ipc, Block *bp)
 			new->newcon = 1;
 			new->ipinterface = s->ipinterface;
 			s->ipinterface->ref++;
+			s->curlog++;
 			new->psrc = sp;
 			new->pdst = dp;
 			new->dst = nhgetl(ih->src);
@@ -240,6 +251,8 @@ drop:
 void
 ilprocess(Ipconv *s, Ilhdr *h, Block *bp)
 {
+	Block *nb;
+
 	switch(s->ilctl.state) {
 	case Ilclosed:
 	case Ilclosing:
@@ -265,10 +278,14 @@ ilprocess(Ipconv *s, Ilhdr *h, Block *bp)
 	case Ildata:
 		ilackto(&s->ilctl, nhgetl(h->ilack));
 		bp->rptr += IL_EHSIZE+IL_HDRSIZE;
+/* Check and trim to length */
 		PUTNEXT(s->readq, bp);
 		break;
 	case Ilreset:
 		s->ilctl.state = Ilclosed;
+		nb = allocb(0);
+		nb->type = M_HANGUP;
+		PUTNEXT(s->readq, nb);
 		freeb(bp);
 	}
 }
@@ -287,17 +304,18 @@ ilsendctl(Ipconv *ipc, Ilhdr *inih, int type, int ack)
 	ic = &ipc->ilctl;
 
 	/* Ip fields */
-	hnputl(ih->src, Myip);
-	hnputl(ih->dst, ipc->dst);
 	ih->proto = IP_ILPROTO;
+	hnputl(ih->src, Myip);
 	hnputs(ih->illen, IL_HDRSIZE);
 	if(inih) {
+		hnputl(ih->dst, nhgetl(inih->src));
 		hnputs(ih->ilsrc, nhgets(inih->ildst));
 		hnputs(ih->ildst, nhgets(inih->ilsrc));
 		hnputl(ih->ilid, nhgetl(inih->ilack));
 		hnputl(ih->ilack, nhgetl(inih->ilid));
 	}
 	else {
+		hnputl(ih->dst, ipc->dst);
 		hnputs(ih->ilsrc, ipc->psrc);
 		hnputs(ih->ildst, ipc->pdst);
 		hnputl(ih->ilid, ic->sent);
@@ -311,7 +329,7 @@ ilsendctl(Ipconv *ipc, Ilhdr *inih, int type, int ack)
 	if(ilcksum)
 		hnputs(ih->ilsum, ptcl_csum(bp, IL_EHSIZE, IL_HDRSIZE));
 
-	if(!ack) {
+	if(!ack && ipc) {
 		ic->sent++;			/* Maybe needs locking */
 		ilackq(&ipc->ilctl, bp);
 	}