Reviewed by: julian

Submitted by:	archie@whistle.com

This patch allows true interface routing to be controlled
from the command line..
you can now do:
route add default -interface ppp0
even if you have no clue what the address at the other end is..

this is part of a set of changes that allow true "unnumbered links"
such as netcom run between their sites..
In practice you should assign the address from one of your ethernet
interfaces to the local side of the P2P link so that IP doesn't
say that the packet comes from 255.255.255.255, but
there is no need whatsoever to assign an address of any kind
to the remote end of the link.. useful for frame relay links etc also.

3 files changed, 46 insertions, 2 deletions

diff --git a/sbin/route/Makefile b/sbin/route/Makefile
index 5a67edaa151a..af97fc0c3142 100644
--- a/sbin/route/Makefile
+++ b/sbin/route/Makefile
@@ -3,7 +3,7 @@
 PROG=	route
 MAN8=	route.8
 SRCS=	route.c keywords.h # ccitt_addr.h
-CFLAGS+=-I.
+CFLAGS+=-I. -Wall
 CLEANFILES+=keywords.h
 BINOWN=	root
 BINMODE=4555
diff --git a/sbin/route/route.8 b/sbin/route/route.8
index 42b2678ecb1f..be13a700835b 100644
--- a/sbin/route/route.8
+++ b/sbin/route/route.8
@@ -177,6 +177,8 @@ no intermediary system to act as a gateway, the
 modifier should be specified;
 the gateway given is the address of this host on the common network,
 indicating the interface to be used for transmission.
+If the interface point to point, the name of the interface
+itself may be given instead.
 .Pp
 The optional modifiers
 .Fl xns ,
diff --git a/sbin/route/route.c b/sbin/route/route.c
index b2d1eb83370e..a823569e813f 100644
--- a/sbin/route/route.c
+++ b/sbin/route/route.c
@@ -43,7 +43,7 @@ static const char copyright[] =
 static char sccsid[] = "@(#)route.c	8.3 (Berkeley) 3/19/94";
 */
 static const char rcsid[] =
-	"$Id: route.c,v 1.10 1996/07/23 01:18:47 julian Exp $";
+	"$Id: route.c,v 1.11 1996/07/23 22:00:14 julian Exp $";
 #endif /* not lint */
 
 #include <sys/param.h>
@@ -827,6 +827,48 @@ getaddr(which, s, hpp)
 		break;
 	case RTA_GATEWAY:
 		su = &so_gate;
+		if (iflag) {
+			#define MAX_IFACES	400
+			int			sock;
+			struct ifreq		iflist[MAX_IFACES];
+			struct ifconf		ifconf;
+			struct ifreq		*ifr, *ifr_end;
+			struct sockaddr_dl	*dl, *sdl = NULL;
+
+			/* Get socket */
+			if ((sock = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
+				err(1, "socket");
+
+			/* Get interface list */
+			ifconf.ifc_req = iflist;
+			ifconf.ifc_len = sizeof(iflist);
+			if (ioctl(sock, SIOCGIFCONF, &ifconf) < 0)
+				err(1, "ioctl(SIOCGIFCONF)");
+			close(sock);
+
+			/* Look for this interface in the list */
+			for (ifr = ifconf.ifc_req,
+			    ifr_end = (struct ifreq *)
+				(ifconf.ifc_buf + ifconf.ifc_len);
+			    ifr < ifr_end;
+			    ifr = (struct ifreq *) ((char *) &ifr->ifr_addr
+						    + ifr->ifr_addr.sa_len)) {
+				dl = (struct sockaddr_dl *)&ifr->ifr_addr;
+				if (ifr->ifr_addr.sa_family == AF_LINK
+				    && (ifr->ifr_flags & IFF_POINTOPOINT)
+				    && !strncmp(s, dl->sdl_data, dl->sdl_nlen)
+				    && s[dl->sdl_nlen] == 0) {
+					sdl = dl;
+					break;
+				}
+			}
+
+			/* If we found it, then use it */
+			if (sdl) {
+				su->sdl = *sdl;
+				return(1);
+			}
+		}
 		su->sa.sa_family = af;
 		break;
 	case RTA_NETMASK: