[src/netbsd-9]: src/sys/netinet Pull up following revision(s) (requested by r...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e453e4a451f6
branches:  netbsd-9
changeset: 462635:e453e4a451f6
user:      martin <martin%NetBSD.org@localhost>
date:      Fri Oct 11 18:22:14 2019 +0000

description:
Pull up following revision(s) (requested by roy in ticket #300):

        sys/netinet/if_arp.c: revision 1.289

ARP: Don't defend ARP probes.

We should let the nature of ARP takes it's course here when our address
is neither tentative nor duplicated.
This allows the host to work with ARP ping, which was broken in r1.279.

diffstat:

 sys/netinet/if_arp.c |  16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)

diffs (41 lines):

diff -r 8fb691e465a5 -r e453e4a451f6 sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Fri Oct 11 18:19:31 2019 +0000
+++ b/sys/netinet/if_arp.c      Fri Oct 11 18:22:14 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.282.2.4 2019/09/30 15:55:40 martin Exp $  */
+/*     $NetBSD: if_arp.c,v 1.282.2.5 2019/10/11 18:22:14 martin Exp $  */
 
 /*
  * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.282.2.4 2019/09/30 15:55:40 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.282.2.5 2019/10/11 18:22:14 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -1157,15 +1157,17 @@
        /*
         * DAD check, RFC 5227.
         * Collision on sender address is always a duplicate.
-        * Collision on target address is only a duplicate IF
-        * the sender address is the null host (ie a DAD probe) AND
-        * the message was broadcast - if it's unicast then it's
-        * a valid Unicast Poll from RFC 1122.
+        * Collision on target address is only a duplicate
+        * IF the sender address is the null host (ie a DAD probe)
+        * AND the message was broadcast
+        * AND our address is either tentative or duplicated
+        * If it was unicast then it's a valid Unicast Poll from RFC 1122.
         */
        if (do_dad &&
            (in_hosteq(isaddr, myaddr) ||
            (in_nullhost(isaddr) && in_hosteq(itaddr, myaddr) &&
-            m->m_flags & M_BCAST)))
+            m->m_flags & M_BCAST &&
+            ia->ia4_flags & (IN_IFF_TENTATIVE | IN_IFF_DUPLICATED))))
        {
                struct sockaddr_dl sdl, *sdlp;