From 0b96d38ea5d87ad8b4b90472aff0fa0ba436ee03 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 14 Oct 1991 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1991-10-14

---
 port/devip.c | 11 ++++++++---
 port/ipdat.h | 26 ++++++++++++++++++++++----
 port/stil.c  | 53 +++++++++++++++++++++++++++++++++++++---------------
 port/tcpif.c |  2 +-
 4 files changed, 69 insertions(+), 23 deletions(-)

diff --git a/port/devip.c b/port/devip.c
index 5494dc7cb51904e67613cf9dfc2669394f3533ca..ffeb29b1923eed7ab5e21b854458806e6495cc10 100644
--- a/port/devip.c
+++ b/port/devip.c
@@ -187,8 +187,10 @@ ipopen(Chan *c, int omode)
 			pushq(c->stream, cp->stproto);
 
 		if(cp->stproto == &tcpinfo)
-			open_tcp(cp, TCP_PASSIVE, Streamhi, 0);
-	
+			tcpstart(cp, TCP_PASSIVE, Streamhi, 0);
+		else if(cp->stproto == &ilinfo)
+			ilstart(cp, IL_PASSIVE, 10);
+
 		iplisten(c, cp, ipconv[c->dev]);
 		break;
 	case Sdataqid:
@@ -197,7 +199,10 @@ ipopen(Chan *c, int omode)
 			pushq(c->stream, cp->stproto);
 
 		if(cp->stproto == &tcpinfo)
-			open_tcp(cp, TCP_ACTIVE, Streamhi, 0);
+			tcpstart(cp, TCP_ACTIVE, Streamhi, 0);
+		else if(cp->stproto == &ilinfo)
+			ilstart(cp, IL_ACTIVE, 10);
+
 		break;
 	case Sctlqid:
 		streamopen(c, &ipinfo);
diff --git a/port/ipdat.h b/port/ipdat.h
index eda2f70fa3f69b7812fe43f3a9360ade232f47da..053621b3f26cbb50be7b108406e5464d361b3a02 100644
--- a/port/ipdat.h
+++ b/port/ipdat.h
@@ -68,7 +68,7 @@ struct Udphdr
 
 struct Ilhdr
 {
-#define IL_EHSIZE	22
+#define IL_EHSIZE	34
 	uchar	d[6];		/* Ethernet destination */
 	uchar	s[6];		/* Ethernet source */
 	uchar	type[2];	/* Ethernet packet type */
@@ -77,6 +77,11 @@ struct Ilhdr
 	uchar	length[2];	/* packet length */
 	uchar	id[2];		/* Identification */
 	uchar	frag[2];	/* Fragment information */
+	uchar	ttl;		/* Time to live */
+	uchar	proto;		/* Protocol */
+	uchar	cksum[2];	/* Header checksum */
+	uchar	src[4];		/* Ip source */
+	uchar	dst[4];		/* Ip destination */
 #define IL_HDRSIZE	16	
 	uchar	ilsum[2];	/* Checksum including header */
 	uchar	illen[2];	/* Packet length */
@@ -88,7 +93,7 @@ struct Ilhdr
 	uchar	ilack[4];	/* Acked sequence */
 };
 
-struct Ilcb
+struct Ilcb				/* Control block */
 {
 	int	state;
 	Block	*unacked;
@@ -98,9 +103,10 @@ struct Ilcb
 	ulong	sent;
 	ulong	recvd;
 	ulong	lastack;
+	int	window;
 };
 
-enum
+enum					/* Packet types */
 {
 	Ilsync,
 	Ildata,
@@ -111,6 +117,16 @@ enum
 	Ilreset,
 };
 
+enum					/* Connection state */
+{
+	Ilclosed,
+	Ilsyncer,
+	Ilsyncee,
+	Ilestablished,
+	Illistening,
+	Ilclosing,
+};
+
 #define TCP_PKT	(TCP_EHSIZE+TCP_IPLEN+TCP_PHDRSIZE)
 
 struct Tcphdr
@@ -292,6 +308,8 @@ struct Ipconv
 
 #define TCP_PASSIVE	0
 #define TCP_ACTIVE	1
+#define IL_PASSIVE	0
+#define IL_ACTIVE	1
 
 #define MAXBACKOFF	5
 #define FORCE		1
@@ -481,7 +499,7 @@ int	backoff(int);
 int	dupb(Block **, Block *, int, int);
 void	tcp_input(Ipconv *, Block *);
 void 	tcprcvwin(Ipconv *);
-void	open_tcp(Ipconv *, int, ushort, char);
+void	tcpstart(Ipconv *, int, ushort, char);
 void	tcpflow(void*);
 void 	tcp_timeout(void *);
 void	tcp_acktimer(void *);
diff --git a/port/stil.c b/port/stil.c
index 32954962dc35d07a8dfcfa053eafb4d64d247e75..e69b8af30a6803f05d49463c14aab99fe9f0f948 100644
--- a/port/stil.c
+++ b/port/stil.c
@@ -14,9 +14,11 @@
 #define DPRINT if(pip)print
 int ilcksum = 1;
 Queue	*Iloutput;		/* Il to lance output channel */
+static int initseq = 25000;
 
 void	ilrcvmsg(Ipconv*, Block*);
 void	ilackproc(void*);
+void	ilsendctl(Ipconv *, Ilhdr *, int);
 
 void
 ilopen(Queue *q, Stream *s)
@@ -126,6 +128,8 @@ void
 ilrcvmsg(Ipconv *ipc, Block *bp)
 {
 	Ilhdr *ih;
+	int plen;
+	Ipconv *s;
 
 	ih = (Ilhdr *)bp;
 
@@ -138,21 +142,12 @@ ilrcvmsg(Ipconv *ipc, Block *bp)
 		goto drop;
 	}
 
-	s = ip_conn(ipc, hngets(ih->ildst), hngets(ih->ilsrc), hngetl(), IP_ILPROTO);
+	s = ip_conn(ipc, nhgets(ih->ildst), nhgets(ih->ilsrc), nhgetl(ih->src), IP_ILPROTO);
 	if(s == 0) {
-		ilsentctl(0, ih, Ilreset);
+		ilsendctl(0, ih, Ilreset);
 		goto drop;
 	}
 
-	switch(s->state) {
-	case Closed:
-		ilsentctl(0, ih, Ilreset);
-		goto drop;
-	case Syncee:
-	case Syncer:
-	case Established:
-	case Closing:
-	}	
 	
 drop:
 	freeb(bp);
@@ -171,10 +166,10 @@ ilsendctl(Ipconv *ipc, Ilhdr *inih, int type)
 
 	hnputs(ih->illen, IL_EHSIZE+IL_HDRSIZE);
 	if(inih) {
-		hnputs(ih->ilsrc, inih->ildst);
-		hnputs(ih->ildst, inih->ilsrc);
-		hnputl(ih->ilid, inih->recvd);
-		hnputl(ih->ilack, inih->sent);
+		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 {
 		hnputs(ih->ilsrc, ipc->psrc);
@@ -197,3 +192,31 @@ void
 ilackproc(void *junk)
 {
 }
+
+void
+ilstart(Ipconv *ipc, int type, int window)
+{
+	Ilcb *ic = &ipc->ilctl;
+
+	if(ic->state != Ilclosed)
+		return;
+
+	ic->unacked = 0;
+	ic->outoforder = 0;
+	initseq += TK2MS(MACHP(0)->ticks);
+	ic->sent = initseq;
+	ic->recvd = ic->sent;
+	ic->lastack = ic->sent;
+	ic->window = window;
+
+	switch(type) {
+	case IL_PASSIVE:
+		ic->state = Illistening;
+		break;
+	case IL_ACTIVE:
+		ic->state = Ilsyncer;
+		ilsendctl(ipc, 0, Ilsync);
+		break;
+	}
+
+}
diff --git a/port/tcpif.c b/port/tcpif.c
index ccfd78af786e5b74f0afe631175c53e62fc4b21a..c87314f96a8a34b2020339a2f4aef3d2b3be3766 100644
--- a/port/tcpif.c
+++ b/port/tcpif.c
@@ -54,7 +54,7 @@ state_upcall(Ipconv *s, char oldstate, char newstate)
 }
 
 void
-open_tcp(Ipconv *s, int mode, ushort window, char tos)
+tcpstart(Ipconv *s, int mode, ushort window, char tos)
 {
 	Tcpctl *tcb = &s->tcpctl;