From 7ab5fa8717ddb27d557e0886c8f4a4f5dd5d05ec Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Mon, 16 Mar 1998 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1998-03-16

---
 ip/ip.h      |  1 -
 ip/ipifc.c   | 20 +++++++++++++++-----
 ip/iproute.c | 31 +++++++++++++++++++++++++------
 3 files changed, 40 insertions(+), 12 deletions(-)

diff --git a/ip/ip.h b/ip/ip.h
index 91bf6cab6df859fd17e38fa8739658c7004aea03..cc663d48388991e6f7970758225c5957db8ecd04 100644
--- a/ip/ip.h
+++ b/ip/ip.h
@@ -8,7 +8,6 @@ typedef struct	Ipselftab	Ipselftab;
 typedef struct	Iplink	Iplink;
 typedef struct	Iplifc	Iplifc;
 typedef struct	Ipmulti	Ipmulti;
-typedef struct	Iproute	Iproute;
 typedef struct	IProuter IProuter;
 typedef struct	Ipifc	Ipifc;
 typedef struct	Log	Log;
diff --git a/ip/ipifc.c b/ip/ipifc.c
index bf74c2e9d61345572bbddc9b0bfb4d65a5023af9..db35fd8c4a8c4fa1a3994e132d910a6b3853be22 100644
--- a/ip/ipifc.c
+++ b/ip/ipifc.c
@@ -360,7 +360,7 @@ ipifcadd(Ipifc *ifc, char **argv, int argc)
 	if(isv4(ip))
 		v4addroute(f, tifc, rem+IPv4off, mask+IPv4off, ip+IPv4off, type);
 	else
-		v6addroute(f, tifc, ip, mask, rem, type);
+		v6addroute(f, tifc, rem, mask, ip, type);
 
 	addselfcache(f, ifc, lifc, ip, Runi);
 
@@ -860,11 +860,15 @@ ipforme(Fs *f, uchar *addr)
 Ipifc*
 findipifc(Fs *f, uchar *remote, int type)
 {
-	Ipifc *ifc;
+	Ipifc *ifc, *x;
 	Iplifc *lifc;
 	Conv **cp, **e;
 	uchar gnet[IPaddrlen];
+	uchar xmask[IPaddrlen];
+
+	x = nil;
 
+	/* find most specific match */
 	e = &f->ipifc->conv[f->ipifc->nc];
 	for(cp = f->ipifc->conv; cp < e; cp++){
 		if(*cp == 0)
@@ -872,12 +876,18 @@ findipifc(Fs *f, uchar *remote, int type)
 		ifc = (Ipifc*)(*cp)->ptcl;
 		for(lifc = ifc->lifc; lifc; lifc = lifc->next){
 			maskip(remote, lifc->mask, gnet);
-			if(ipcmp(gnet, lifc->net) == 0)
-				return ifc;
+			if(ipcmp(gnet, lifc->net) == 0){
+				if(x == nil || ipcmp(lifc->mask, xmask) > 0){
+					x = ifc;
+					ipmove(xmask, lifc->mask);
+				}
+			}
 		}
 	}
+	if(x != nil)
+		return x;
 
-	/* for now for broadcast and mutlicast, just use first interface */
+	/* for now for broadcast and multicast, just use first interface */
 	if(type & (Rbcast|Rmulti)){
 		for(cp = f->ipifc->conv; cp < e; cp++){
 			if(*cp == 0)
diff --git a/ip/iproute.c b/ip/iproute.c
index 4bf022e34c22990dd9c89d5ab30d9edf1711f37c..bd3e09476395406546036e2c138294a886551893 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -263,7 +263,15 @@ addnode(Fs *f, Route **cur, Route *new)
 		addqueue(&f->queue, p);
 		break;
 	case Requals:
-		copygate(p, new);
+		/*
+		 *  supercede the old entry if the old one isn't
+		 *  a local interface.
+		 */
+		if((p->type & Rifc) == 0){
+			p->type = new->type;
+			p->ifcid = -1;
+			copygate(p, new);
+		}
 		freeroute(new);
 		break;
 	case Rcontained:
@@ -471,7 +479,11 @@ v4lookup(Fs *f, uchar *a)
 			p = p->left;
 
 	if(q && (q->ifc == nil || q->ifcid != q->ifc->ifcid)){
-		v4tov6(gate, q->v4.gate);
+		if(q->type & Rifc) {
+			hnputl(gate+IPv4off, q->v4.address);
+			memmove(gate, v4prefix, IPv4off);
+		} else
+			v4tov6(gate, q->v4.gate);
 		q->ifc = findipifc(f, gate, q->type);
 		if(q->ifc == nil)
 			return nil;
@@ -488,6 +500,7 @@ v6lookup(Fs *f, uchar *a)
 	ulong la[IPllen];
 	int h;
 	ulong x, y;
+	uchar gate[IPaddrlen];
 
 	if(memcmp(a, v4prefix, 12) == 0){
 		q = v4lookup(f, a+12);
@@ -527,12 +540,18 @@ v6lookup(Fs *f, uchar *a)
 next:		;
 	}
 
-	if(q && q->ifc == nil){
-		q->ifc = findipifc(f, q->v6.gate, q->type);
+	if(q && (q->ifc == nil || q->ifcid != q->ifc->ifcid)){
+		if(q->type & Rifc) {
+			hnputl(gate, q->v6.gate[0]);
+			hnputl(gate+4, q->v6.gate[1]);
+			hnputl(gate+8, q->v6.gate[2]);
+			hnputl(gate+12, q->v6.gate[3]);
+			q->ifc = findipifc(f, gate, q->type);
+		} else
+			q->ifc = findipifc(f, q->v6.gate, q->type);
 		if(q->ifc == nil)
 			return nil;
-		if(q->ifcid != q->ifc->ifcid)
-			return nil;
+		q->ifcid = q->ifc->ifcid;
 	}
 	
 	return q;