Added a fix for a bug which caused the wrong interface to be selected

for broadcasts if point-to-point links shared the same IP address as
the ethernet. The fix must be enabled with P2P_LOCALADDR_SHARE option
in the kernel config file. This will someday likely be standard, but
there isn't sufficient time before release to determine if there are
any interoperability problems with routed and/or gated.

Reviewed by:	Garrett Wollman, and me
Submitted by:	Peter Wemm

1 files changed, 45 insertions, 28 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index e8a11e9..3756159 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)if.c	8.3 (Berkeley) 1/4/94
- * $Id: if.c,v 1.12 1994/12/30 06:46:20 davidg Exp $
+ * $Id: if.c,v 1.13 1995/02/24 11:47:31 davidg Exp $
  */
 
 #include <sys/param.h>
@@ -233,24 +233,33 @@ ifa_ifwithnet(addr)
 	    if (sdl->sdl_index && sdl->sdl_index <= if_index)
 		return (ifnet_addrs[sdl->sdl_index - 1]);
 	}
-	for (ifp = ifnet; ifp; ifp = ifp->if_next)
-	    for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
-		register char *cp, *cp2, *cp3;
-
-		if (ifa->ifa_addr->sa_family != af || ifa->ifa_netmask == 0)
-			next: continue;
-		cp = addr_data;
-		cp2 = ifa->ifa_addr->sa_data;
-		cp3 = ifa->ifa_netmask->sa_data;
-		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
-		while (cp3 < cplim)
-			if ((*cp++ ^ *cp2++) & *cp3++)
-				goto next;
-		if (ifa_maybe == 0 ||
-		    rn_refines((caddr_t)ifa->ifa_netmask,
-		    (caddr_t)ifa_maybe->ifa_netmask))
-			ifa_maybe = ifa;
-	    }
+	for (ifp = ifnet; ifp; ifp = ifp->if_next) {
+		for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next) {
+			register char *cp, *cp2, *cp3;
+
+			if (ifa->ifa_addr->sa_family != af || ifa->ifa_netmask == 0)
+				next: continue;
+#ifdef P2P_LOCALADDR_SHARE
+			if (ifp->if_flags & IFF_POINTOPOINT) {
+				if (equal(addr, ifa->ifa_addr))
+ 					return (ifa);
+			} else
+#endif /* P2P_LOCALADDR_SHARE */
+			{
+				cp = addr_data;
+				cp2 = ifa->ifa_addr->sa_data;
+				cp3 = ifa->ifa_netmask->sa_data;
+				cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
+				while (cp3 < cplim)
+					if ((*cp++ ^ *cp2++) & *cp3++)
+						goto next;
+				if (ifa_maybe == 0 ||
+				    rn_refines((caddr_t)ifa->ifa_netmask,
+				    (caddr_t)ifa_maybe->ifa_netmask))
+					ifa_maybe = ifa;
+			}
+		}
+	}
 	return (ifa_maybe);
 }
 
@@ -298,15 +307,23 @@ ifaof_ifpforaddr(addr, ifp)
 				return (ifa);
 			continue;
 		}
-		cp = addr->sa_data;
-		cp2 = ifa->ifa_addr->sa_data;
-		cp3 = ifa->ifa_netmask->sa_data;
-		cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
-		for (; cp3 < cplim; cp3++)
-			if ((*cp++ ^ *cp2++) & *cp3)
-				break;
-		if (cp3 == cplim)
-			return (ifa);
+#ifdef P2P_LOCALADDR_SHARE
+		if (ifp->if_flags & IFF_POINTOPOINT) {
+			if (equal(addr, ifa->ifa_dstaddr))
+				return (ifa);
+		} else
+#endif /* P2P_LOCALADDR_SHARE */
+		{
+			cp = addr->sa_data;
+			cp2 = ifa->ifa_addr->sa_data;
+			cp3 = ifa->ifa_netmask->sa_data;
+			cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
+			for (; cp3 < cplim; cp3++)
+				if ((*cp++ ^ *cp2++) & *cp3)
+					break;
+			if (cp3 == cplim)
+				return (ifa);
+		}
 	}
 	return (ifa_maybe);
 }