From: Mike Karels <karels@ucbvax.Berkeley.EDU>
Date: Mon, 21 Apr 1986 14:34:38 +0000 (-0800)
Subject: changes to allow subnets to remain local, propogate net route
X-Git-Tag: BSD-4_3-Snapshot-Development~2691
X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/commitdiff_plain/4fad5a6eeb6297fea5e2a7c10ee0fe5db9cd1192

changes to allow subnets to remain local, propogate net route
where subnets don't go, and allow external routes from /etc/gateways
to block routed from installing routes from elsewhere

SCCS-vsn: sbin/routed/af.c 5.4
SCCS-vsn: sbin/routed/af.h 5.3
SCCS-vsn: sbin/routed/if.c 5.3
SCCS-vsn: sbin/routed/inet.c 5.2
SCCS-vsn: sbin/routed/input.c 5.4
SCCS-vsn: sbin/routed/interface.h 5.3
SCCS-vsn: sbin/routed/main.c 5.7
SCCS-vsn: sbin/routed/output.c 5.2
SCCS-vsn: sbin/routed/startup.c 5.4
SCCS-vsn: sbin/routed/table.h 5.2
SCCS-vsn: sbin/routed/tables.c 5.3
---

diff --git a/usr/src/sbin/routed/af.c b/usr/src/sbin/routed/af.c
index a6e02577f9..67d273e69e 100644
--- a/usr/src/sbin/routed/af.c
+++ b/usr/src/sbin/routed/af.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)af.c	5.3 (Berkeley) %G%";
+static char sccsid[] = "@(#)af.c	5.4 (Berkeley) %G%";
 #endif not lint
 
 #include "defs.h"
@@ -15,16 +15,22 @@ static char sccsid[] = "@(#)af.c	5.3 (Berkeley) %G%";
  */
 int	inet_hash(), inet_netmatch(), inet_output(),
 	inet_portmatch(), inet_portcheck(),
-	inet_checkhost(), inet_ishost(), inet_canon();
+	inet_checkhost(), inet_rtflags(), inet_sendsubnet(), inet_canon();
 char	*inet_format();
+
 #define NIL	{ 0 }
 #define	INET \
 	{ inet_hash,		inet_netmatch,		inet_output, \
 	  inet_portmatch,	inet_portcheck,		inet_checkhost, \
-	  inet_ishost,		inet_canon, 		inet_format }
+	  inet_rtflags,		inet_sendsubnet,	inet_canon, \
+	  inet_format \
+	}
 
-struct afswitch afswitch[AF_MAX] =
-	{ NIL, NIL, INET, };
+struct afswitch afswitch[AF_MAX] = {
+	NIL,		/* 0- unused */
+	NIL,		/* 1- Unix domain, unused */
+	INET,		/* Internet */
+};
 
 int af_max = sizeof(afswitch) / sizeof(afswitch[0]);
 
@@ -111,17 +117,6 @@ inet_checkhost(sin)
 	return (1);
 }
 
-/*
- * Return 1 if the address is
- * for an Internet host, 0 for a network.
- */
-inet_ishost(sin)
-	struct sockaddr_in *sin;
-{
-
-	return (inet_lnaof(sin->sin_addr) != 0);
-}
-
 inet_canon(sin)
 	struct sockaddr_in *sin;
 {
diff --git a/usr/src/sbin/routed/af.h b/usr/src/sbin/routed/af.h
index ac8ceff595..b9b825f1ea 100644
--- a/usr/src/sbin/routed/af.h
+++ b/usr/src/sbin/routed/af.h
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
- *	@(#)af.h	5.2 (Berkeley) %G%
+ *	@(#)af.h	5.3 (Berkeley) %G%
  */
 
 /*
@@ -19,8 +19,9 @@ struct afswitch {
 	int	(*af_output)();		/* interprets address for sending */
 	int	(*af_portmatch)();	/* packet from some other router? */
 	int	(*af_portcheck)();	/* packet from privileged peer? */
-	int	(*af_checkhost)();	/* tells if address for host or net */
-	int	(*af_ishost)();		/* tells if address is valid */
+	int	(*af_checkhost)();	/* tells if address is valid */
+	int	(*af_rtflags)();	/* get flags for route (host or net) */
+	int	(*af_sendsubnet)();	/* check bounds of subnet broadcast */
 	int	(*af_canon)();		/* canonicalize address for compares */
 	char	*(*af_format)();	/* convert address to string */
 };
diff --git a/usr/src/sbin/routed/if.c b/usr/src/sbin/routed/if.c
index dc2fd5ce4f..6f49efbeb2 100644
--- a/usr/src/sbin/routed/if.c
+++ b/usr/src/sbin/routed/if.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)if.c	5.2 (Berkeley) %G%";
+static char sccsid[] = "@(#)if.c	5.3 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -109,6 +109,9 @@ if_iflookup(addr)
 		if ((ifp->int_flags & IFF_BROADCAST) &&
 		    same(&ifp->int_broadaddr, addr))
 			break;
+		if ((ifp->int_flags & IFF_POINTOPOINT) &&
+		    same(&ifp->int_dstaddr, addr))
+			break;
 		if (maybe == 0 && (*netmatch)(addr, &ifp->int_addr))
 			maybe = ifp;
 	}
diff --git a/usr/src/sbin/routed/inet.c b/usr/src/sbin/routed/inet.c
index 4514725608..3e688cbbf4 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	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)inet.c	5.2 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -100,3 +100,68 @@ inet_lnaof(in)
 			return (host &~ ifp->int_subnetmask);
 	return (host);
 }
+
+/*
+ * Return RTF_HOST if the address is
+ * for an Internet host, RTF_SUBNET for a subnet,
+ * 0 for a network.
+ */
+inet_rtflags(sin)
+	struct sockaddr_in *sin;
+{
+	register u_long i = ntohl(sin->sin_addr.s_addr);
+	register u_long net, host;
+	register struct interface *ifp;
+
+	if (IN_CLASSA(i)) {
+		net = i & IN_CLASSA_NET;
+		host = i & IN_CLASSA_HOST;
+	} else if (IN_CLASSB(i)) {
+		net = i & IN_CLASSB_NET;
+		host = i & IN_CLASSB_HOST;
+	} else {
+		net = i & IN_CLASSC_NET;
+		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)
+				return (RTF_SUBNET);
+			else
+				return (RTF_HOST);
+		}
+	return (RTF_HOST);
+}
+
+/*
+ * Return true if a route to subnet rtsin 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).
+ */
+inet_sendsubnet(rtsin, dst)
+	struct sockaddr_in *rtsin, *dst;
+{
+	register u_long rt = ntohl(rtsin->sin_addr.s_addr);
+	register u_long d = ntohl(dst->sin_addr.s_addr);
+
+	if (IN_CLASSA(rt)) {
+		if ((rt & IN_CLASSA_HOST) == 0)
+			return (1);
+		return ((rt & IN_CLASSA_NET) == (d & IN_CLASSA_NET));
+	} else if (IN_CLASSB(rt)) {
+		if ((rt & IN_CLASSB_HOST) == 0)
+			return (1);
+		return ((rt & IN_CLASSB_NET) == (d & IN_CLASSB_NET));
+	} else {
+		if ((rt & IN_CLASSC_HOST) == 0)
+			return (1);
+		return ((rt & IN_CLASSC_NET) == (d & IN_CLASSC_NET));
+	}
+}
diff --git a/usr/src/sbin/routed/input.c b/usr/src/sbin/routed/input.c
index 035ecf6aec..42da57cb9a 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	5.3 (Berkeley) %G%";
+static char sccsid[] = "@(#)input.c	5.4 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -63,7 +63,7 @@ rip_input(from, size)
 			if (n->rip_dst.sa_family == AF_UNSPEC &&
 			    n->rip_metric == HOPCNT_INFINITY && size == 0) {
 			    	if (supplier || (*afp->af_portmatch)(from) == 0)
-					supply(from, 0, ifp);
+					supply(from, 0, 0);
 				return;
 			}
 			if (n->rip_dst.sa_family < af_max &&
diff --git a/usr/src/sbin/routed/interface.h b/usr/src/sbin/routed/interface.h
index 2c3e5ac6d6..857728a0a1 100644
--- a/usr/src/sbin/routed/interface.h
+++ b/usr/src/sbin/routed/interface.h
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
- *	@(#)interface.h	5.2 (Berkeley) %G%
+ *	@(#)interface.h	5.3 (Berkeley) %G%
  */
 
 /*
@@ -52,10 +52,12 @@ struct interface {
 #define	IFF_LOOPBACK	0x8		/* software loopback net */
 #define	IFF_POINTOPOINT	0x10		/* interface is point-to-point link */
 
+#define	IFF_SUBNET	0x1000		/* interface on subnetted network */
 #define	IFF_PASSIVE	0x2000		/* can't tell if up/down */
 #define	IFF_INTERFACE	0x4000		/* hardware interface */
 #define	IFF_REMOTE	0x8000		/* interface isn't on this machine */
 
 struct	interface *if_ifwithaddr();
+struct	interface *if_ifwithdstaddr();
 struct	interface *if_ifwithnet();
 struct	interface *if_iflookup();
diff --git a/usr/src/sbin/routed/main.c b/usr/src/sbin/routed/main.c
index 9c766eb391..a4608bcb27 100644
--- a/usr/src/sbin/routed/main.c
+++ b/usr/src/sbin/routed/main.c
@@ -11,7 +11,7 @@ char copyright[] =
 #endif not lint
 
 #ifndef lint
-static char sccsid[] = "@(#)main.c	5.6 (Berkeley) %G%";
+static char sccsid[] = "@(#)main.c	5.7 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -24,7 +24,6 @@ static char sccsid[] = "@(#)main.c	5.6 (Berkeley) %G%";
 #include <net/if.h>
 
 #include <errno.h>
-#include <nlist.h>
 #include <signal.h>
 #include <syslog.h>
 
diff --git a/usr/src/sbin/routed/output.c b/usr/src/sbin/routed/output.c
index 530235b3e4..09ec259ca6 100644
--- a/usr/src/sbin/routed/output.c
+++ b/usr/src/sbin/routed/output.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)output.c	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)output.c	5.2 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -68,12 +68,33 @@ supply(dst, flags, ifp)
 	struct rthash *base = hosthash;
 	int doinghost = 1, size;
 	int (*output)() = afswitch[dst->sa_family].af_output;
+	int (*sendsubnet)() = afswitch[dst->sa_family].af_sendsubnet;
 
 	msg->rip_cmd = RIPCMD_RESPONSE;
 	msg->rip_vers = RIPVERSION;
 again:
 	for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++)
 	for (rt = rh->rt_forw; rt != (struct rt_entry *)rh; rt = rt->rt_forw) {
+		/*
+		 * Don't resend the information
+		 * on the network from which it was received.
+		 */
+		if (ifp && rt->rt_ifp == ifp)
+			continue;
+		if (rt->rt_state & RTS_EXTERNAL)
+			continue;
+		/*
+		 * Limit the spread of subnet information
+		 * to those who are interested.
+		 */
+		if (doinghost == 0 && rt->rt_state & RTS_SUBNET) {
+			if (ifp && (ifp->int_flags & IFF_SUBNET) == 0)
+				continue;
+			if (rt->rt_dst.sa_family != dst->sa_family)
+				continue;
+			if ((*sendsubnet)(&rt->rt_dst, dst) == 0)
+				continue;
+		}
 		size = (char *)n - packet;
 		if (size > MAXPACKETSIZE - sizeof (struct netinfo)) {
 			(*output)(s, flags, dst, size);
diff --git a/usr/src/sbin/routed/startup.c b/usr/src/sbin/routed/startup.c
index 6438276a29..5f4d24424f 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	5.3 (Berkeley) %G%";
+static char sccsid[] = "@(#)startup.c	5.4 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -14,12 +14,10 @@ static char sccsid[] = "@(#)startup.c	5.3 (Berkeley) %G%";
 #include "defs.h"
 #include <sys/ioctl.h>
 #include <net/if.h>
-#include <nlist.h>
 #include <syslog.h>
 
 struct	interface *ifnet;
 int	lookforinterfaces = 1;
-int	performnlist = 1;
 int	externalinterfaces = 0;		/* # of remote and local interfaces */
 
 /*
@@ -108,6 +106,8 @@ ifinit()
 			ifs.int_netmask = IN_CLASSC_NET;
 		ifs.int_net = i & ifs.int_netmask;
 		ifs.int_subnet = i & ifs.int_subnetmask;
+		if (ifs.int_subnetmask != ifs.int_netmask)
+			ifs.int_flags |= IFF_SUBNET;
 		ifp = (struct interface *)malloc(sizeof (struct interface));
 		if (ifp == 0) {
 			printf("routed: out of memory\n");
@@ -153,6 +153,12 @@ bad:
 	_exit(0177);
 }
 
+/*
+ * Add route for interface if not currently installed.
+ * Create route to other end if a point-to-point link,
+ * otherwise a route to this (sub)network.
+ * INTERNET SPECIFIC.
+ */
 addrouteforif(ifp)
 	struct interface *ifp;
 {
@@ -177,7 +183,22 @@ addrouteforif(ifp)
 	if (ifp->int_transitions++ > 0)
 		syslog(LOG_ERR, "re-installing interface %s", ifp->int_name);
 	rtadd(dst, &ifp->int_addr, ifp->int_metric,
-		ifp->int_flags & (IFF_INTERFACE|IFF_PASSIVE|IFF_REMOTE));
+	    ifp->int_flags & (IFF_INTERFACE|IFF_PASSIVE|IFF_REMOTE|IFF_SUBNET));
+
+	/*
+	 * If interface on subnetted network,
+	 * install route to network as well.
+	 * This is meant for external viewers.
+	 */
+	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))
+			return;
+		rtadd(dst, &ifp->int_addr, ifp->int_metric,
+		    (ifp->int_flags & (IFF_INTERFACE|IFF_PASSIVE|IFF_REMOTE) |
+			RTS_INTERNAL));
+	}
 }
 
 /*
@@ -241,6 +262,16 @@ gwkludge()
 			(void) ioctl(s, SIOCADDRT, (char *)&route.rt_rt);
 			continue;
 		}
+		if (strcmp(qual, "external") == 0) {
+			/*
+			 * Entries marked external are handled
+			 * by other means, e.g. EGP,
+			 * and are placed in our tables only
+			 * to prevent overriding them
+			 * with something else.
+			 */
+			rtadd(&dst, &gate, metric, RTS_EXTERNAL|RTS_PASSIVE);
+		}
 		/* assume no duplicate entries */
 		externalinterfaces++;
 		ifp = (struct interface *)malloc(sizeof (*ifp));
diff --git a/usr/src/sbin/routed/table.h b/usr/src/sbin/routed/table.h
index e2379ded03..0664e9e329 100644
--- a/usr/src/sbin/routed/table.h
+++ b/usr/src/sbin/routed/table.h
@@ -3,7 +3,7 @@
  * All rights reserved.  The Berkeley software License Agreement
  * specifies the terms and conditions for redistribution.
  *
- *	@(#)table.h	5.1 (Berkeley) %G%
+ *	@(#)table.h	5.2 (Berkeley) %G%
  */
 
 /*
@@ -56,9 +56,17 @@ struct rt_entry {
  * "State" of routing table entry.
  */
 #define	RTS_CHANGED	0x1		/* route has been altered recently */
+#define	RTS_EXTERNAL	0x2		/* extern info, not installed or sent */
+#define	RTS_INTERNAL	0x4		/* internal route, not installed */
 #define	RTS_PASSIVE	IFF_PASSIVE	/* don't time out route */
 #define	RTS_INTERFACE	IFF_INTERFACE	/* route is for network interface */
 #define	RTS_REMOTE	IFF_REMOTE	/* route is for ``remote'' entity */
+#define	RTS_SUBNET	IFF_SUBNET	/* route is for network subnet */
+
+/*
+ * Flags are same as kernel, with this addition for af_rtflags:
+ */
+#define	RTF_SUBNET	0x8000		/* pseudo: route to subnet */
 
 struct	rthash nethash[ROUTEHASHSIZ];
 struct	rthash hosthash[ROUTEHASHSIZ];
diff --git a/usr/src/sbin/routed/tables.c b/usr/src/sbin/routed/tables.c
index 364f5fbe06..60a7b7f627 100644
--- a/usr/src/sbin/routed/tables.c
+++ b/usr/src/sbin/routed/tables.c
@@ -5,7 +5,7 @@
  */
 
 #ifndef lint
-static char sccsid[] = "@(#)tables.c	5.2 (Berkeley) %G%";
+static char sccsid[] = "@(#)tables.c	5.3 (Berkeley) %G%";
 #endif not lint
 
 /*
@@ -112,7 +112,14 @@ rtadd(dst, gate, metric, state)
 	if (af >= af_max)
 		return;
 	(*afswitch[af].af_hash)(dst, &h);
-	flags = (*afswitch[af].af_ishost)(dst) ? RTF_HOST : 0;
+	flags = (*afswitch[af].af_rtflags)(dst);
+	/*
+	 * Subnet flag isn't visible to kernel, move to state.	XXX
+	 */
+	if (flags & RTF_SUBNET) {
+		state |= RTS_SUBNET;
+		flags &= ~RTF_SUBNET;
+	}
 	if (flags & RTF_HOST) {
 		hash = h.afh_hosthash;
 		rh = &hosthash[hash & ROUTEHASHMASK];
@@ -130,7 +137,9 @@ rtadd(dst, gate, metric, state)
 	rt->rt_timer = 0;
 	rt->rt_flags = RTF_UP | flags;
 	rt->rt_state = state | RTS_CHANGED;
-	rt->rt_ifp = if_ifwithnet(&rt->rt_router);
+	rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);
+	if (rt->rt_ifp == 0)
+		rt->rt_ifp = if_ifwithnet(&rt->rt_router);
 	if (metric)
 		rt->rt_flags |= RTF_GATEWAY;
 	insque(rt, rh);
@@ -140,7 +149,8 @@ rtadd(dst, gate, metric, state)
 	 * from this host, discard the entry.  This should only
 	 * occur because of an incorrect entry in /etc/gateways.
 	 */
-	if (install && ioctl(s, SIOCADDRT, (char *)&rt->rt_rt) < 0) {
+	if (install && (rt->rt_state & (RTS_INTERNAL | RTS_EXTERNAL)) == 0 &&
+	    ioctl(s, SIOCADDRT, (char *)&rt->rt_rt) < 0) {
 		perror("SIOCADDRT");
 		if (errno == ENETUNREACH) {
 			TRACE_ACTION(DELETE, rt);
@@ -158,7 +168,7 @@ rtchange(rt, gate, metric)
 	int doioctl = 0, metricchanged = 0;
 	struct rtentry oldroute;
 
-	if (!equal(&rt->rt_router, gate))
+	if (!equal(&rt->rt_router, gate) && (rt->rt_state & RTS_INTERNAL) == 0)
 		doioctl++;
 	if (metric != rt->rt_metric)
 		metricchanged++;
@@ -167,6 +177,9 @@ rtchange(rt, gate, metric)
 		if (doioctl) {
 			oldroute = rt->rt_rt;
 			rt->rt_router = *gate;
+			rt->rt_ifp = if_ifwithdstaddr(&rt->rt_router);
+			if (rt->rt_ifp == 0)
+				rt->rt_ifp = if_ifwithnet(&rt->rt_router);
 		}
 		rt->rt_metric = metric;
 		if ((rt->rt_state & RTS_INTERFACE) && metric) {
@@ -198,7 +211,8 @@ rtdelete(rt)
 		syslog(LOG_ERR, "deleting route to interface %s (timed out)",
 			rt->rt_ifp->int_name);
 	TRACE_ACTION(DELETE, rt);
-	if (install && ioctl(s, SIOCDELRT, (char *)&rt->rt_rt))
+	if (install && (rt->rt_state & (RTS_INTERNAL | RTS_EXTERNAL) == 0) &&
+	    ioctl(s, SIOCDELRT, (char *)&rt->rt_rt))
 		perror("SIOCDELRT");
 	remque(rt);
 	free((char *)rt);
@@ -213,26 +227,10 @@ rtdelete(rt)
  */
 rtdefault()
 {
-	struct afhash h;
-	register struct rt_entry *rt;
-	struct rthash *rh;
 	extern struct sockaddr inet_default;
 
-	rt = (struct rt_entry *)malloc(sizeof (*rt));
-	if (rt == 0)
-		return;
-	rt->rt_dst = inet_default;
-	rt->rt_router = rt->rt_dst;
-	(*afswitch[AF_INET].af_hash)(&rt->rt_dst, &h);
-	rh = &nethash[h.afh_nethash & ROUTEHASHMASK];
-	rt->rt_hash = h.afh_nethash;
-	rt->rt_metric = 0;
-	rt->rt_timer = 0;
-	rt->rt_flags = RTF_UP | RTF_GATEWAY;
-	rt->rt_state = RTS_CHANGED | RTS_PASSIVE;
-	rt->rt_ifp = 0;
-	insque(rt, rh);
-	TRACE_ACTION(ADD, rt);
+	rtadd(&inet_default, &inet_default, 0,
+		RTS_CHANGED | RTS_PASSIVE | RTS_INTERNAL);
 }
 
 rtinit()