unbreak configurations using carppeers

ip_carp.c r1.322 removed the ability to receive carp protocol packets
on !IFT_CARP interfaces. however, carppeers cause the carp protocol
packets to be directed to a unicast address on another interface,
which definitely is not mapped back to a carp interface.

this brings back the ability to get carp packets on parent interfaces.
it is a bit different to a backout because it only allows carp
parents to be ethernet interfaces.

mpi@ told me carp regress tests were failing.

diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
index 0faae32..bb9fa42 100644 (file)
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ip_carp.c,v 1.325 2018/01/12 00:36:13 dlg Exp $       */
+/*     $OpenBSD: ip_carp.c,v 1.326 2018/01/12 23:29:37 dlg Exp $       */
 
 /*
  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
@@ -450,7 +450,14 @@ carp_proto_input_if(struct ifnet *ifp, struct mbuf **mp, int *offp, int proto)
        ismulti = IN_MULTICAST(ip->ip_dst.s_addr);
 
        /* check if received on a valid carp interface */
-       if (ifp->if_type != IFT_CARP) {
+       switch (ifp->if_type) {
+       case IFT_CARP:
+               break;
+       case IFT_ETHER:
+               if (ismulti || !SRPL_EMPTY_LOCKED(&ifp->if_carp))
+                       break;
+               /* FALLTHROUGH */
+       default:
                carpstat_inc(carps_badif);
                CARP_LOG(LOG_INFO, sc,
                    ("packet received on non-carp interface: %s",