From 97cb3618f52ffa5e333e433f13b2c9a9ebffcb27 Mon Sep 17 00:00:00 2001
From: Mike Karels <karels@ucbvax.Berkeley.EDU>
Date: Tue, 3 Jun 1986 23:32:35 -0800
Subject: [PATCH] try again; can't block subnet 0 with internal "network" route

SCCS-vsn: sbin/routed/inet.c 5.4
SCCS-vsn: sbin/routed/input.c 5.6
SCCS-vsn: sbin/routed/startup.c 5.6
---
 usr/src/sbin/routed/inet.c    | 31 ++++++++++++++++++++-----------
 usr/src/sbin/routed/input.c   |  6 ++++--
 usr/src/sbin/routed/startup.c |  9 +++++----
 3 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/usr/src/sbin/routed/inet.c b/usr/src/sbin/routed/inet.c
index f7498eceb0..ef7c52eec8 100644
--- a/usr/src/sbin/routed/inet.c
+++ b/usr/src/sbin/routed/inet.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)inet.c	5.3 (Berkeley) %G%";
+static char sccsid[] = "@(#)inet.c	5.4 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -124,26 +124,29 @@ inet_rtflags(sin)
 		host = i & IN_CLASSC_HOST;
 	}
 
-	if (host == 0)
-		return (0);	/* network */
 	/*
 	 * Check whether this network is subnetted;
 	 * if so, check whether this is a subnet or a host.
 	 */
 	for (ifp = ifnet; ifp; ifp = ifp->int_next)
 		if (net == ifp->int_net) {
-			if ((host &~ ifp->int_subnetmask) == 0)
+			if (host &~ ifp->int_subnetmask)
+				return (RTF_HOST);
+			else if (ifp->int_subnetmask != ifp->int_netmask)
 				return (RTF_SUBNET);
 			else
-				return (RTF_HOST);
+				return (0);		/* network */
 		}
-	return (RTF_HOST);
+	if (host == 0)
+		return (0);	/* network */
+	else
+		return (RTF_HOST);
 }
 
 /*
- * Return true if a route to subnet rtsin should be sent to dst.
+ * Return true if a route to subnet of route rt should be sent to dst.
  * Send it only if dst is on the same logical network,
- * or the route turns out to be for the net (aka subnet 0).
+ * or the route is the "internal" route for the net.
  */
 inet_sendsubnet(rt, dst)
 	struct rt_entry *rt;
@@ -159,20 +162,26 @@ inet_sendsubnet(rt, dst)
 				return ((rt->rt_state & RTS_INTERNAL) == 0);
 			return (1);
 		}
-		return ((r & IN_CLASSA_HOST) == 0);
+		if (r & IN_CLASSA_HOST)
+			return (0);
+		return ((rt->rt_state & RTS_INTERNAL) != 0);
 	} else if (IN_CLASSB(r)) {
 		if ((r & IN_CLASSB_NET) == (d & IN_CLASSB_NET)) {
 			if ((r & IN_CLASSB_HOST) == 0)
 				return ((rt->rt_state & RTS_INTERNAL) == 0);
 			return (1);
 		}
-		return ((r & IN_CLASSB_HOST) == 0);
+		if (r & IN_CLASSB_HOST)
+			return (0);
+		return ((rt->rt_state & RTS_INTERNAL) != 0);
 	} else {
 		if ((r & IN_CLASSC_NET) == (d & IN_CLASSC_NET)) {
 			if ((r & IN_CLASSC_HOST) == 0)
 				return ((rt->rt_state & RTS_INTERNAL) == 0);
 			return (1);
 		}
-		return ((r & IN_CLASSC_HOST) == 0);
+		if (r & IN_CLASSC_HOST)
+			return (0);
+		return ((rt->rt_state & RTS_INTERNAL) != 0);
 	}
 }
diff --git a/usr/src/sbin/routed/input.c b/usr/src/sbin/routed/input.c
index 6eee6d2848..e96cfbf6b1 100644
--- a/usr/src/sbin/routed/input.c
+++ b/usr/src/sbin/routed/input.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)input.c	5.5 (Berkeley) %G%";
+static char sccsid[] = "@(#)input.c	5.6 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -164,7 +164,9 @@ rip_input(from, size)
 				continue;
 			}
 			rt = rtlookup(&n->rip_dst);
-			if (rt == 0) {
+			if (rt == 0 ||
+			    (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
+			    (RTS_INTERNAL|RTS_INTERFACE)) {
 				rt = rtfind(&n->rip_dst);
 				if (rt && equal(from, &rt->rt_router) &&
 				    rt->rt_metric == n->rip_metric)
diff --git a/usr/src/sbin/routed/startup.c b/usr/src/sbin/routed/startup.c
index 92ef9b7c95..a3a4ece893 100644
--- a/usr/src/sbin/routed/startup.c
+++ b/usr/src/sbin/routed/startup.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)startup.c	5.5 (Berkeley) %G%";
+static char sccsid[] = "@(#)startup.c	5.6 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -193,11 +193,12 @@ addrouteforif(ifp)
 	if ((ifp->int_flags & (IFF_SUBNET|IFF_POINTOPOINT)) == IFF_SUBNET) {
 		net.sin_addr = inet_makeaddr(ifp->int_net, INADDR_ANY);
 		rt = rtfind(dst);
-		if (rt && (rt->rt_state & RTS_INTERFACE))
+		if (rt && (rt->rt_state & (RTS_INTERNAL | RTS_INTERFACE)) ==
+		    (RTS_INTERNAL | RTS_INTERFACE))
 			return;
 		rtadd(dst, &ifp->int_addr, ifp->int_metric,
-		    (ifp->int_flags & (IFF_INTERFACE|IFF_PASSIVE|IFF_REMOTE) |
-			RTS_INTERNAL | RTS_SUBNET));
+		    ((ifp->int_flags & (IFF_INTERFACE|IFF_REMOTE)) |
+			RTS_PASSIVE | RTS_INTERNAL | RTS_SUBNET));
 	}
 }
 
-- 
2.20.1