From 94de0377ab158849ffeb7338106a95b32a538d34 Mon Sep 17 00:00:00 2001
From: hrs <hrs@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Thu, 23 Jul 2015 19:58:56 +0000
Subject: [PATCH] MFC r282805:

- Remove ND6_IFF_IGNORELOOP.  This functionality was useless in practice
  because a link where looped back NS messages are permanently observed
  does not work with either NDP or ARP for IPv4.

- draft-ietf-6man-enhanced-dad is now RFC 7527.

Approved by:	re (gjb)


git-svn-id: svn://svn.freebsd.org/base/stable/10@285825 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sbin/ifconfig/af_inet6.c |  2 --
 sbin/ifconfig/ifconfig.8 | 11 +----------
 sys/netinet6/nd6.h       |  3 +--
 sys/netinet6/nd6_nbr.c   | 17 +++--------------
 4 files changed, 5 insertions(+), 28 deletions(-)

diff --git a/sbin/ifconfig/af_inet6.c b/sbin/ifconfig/af_inet6.c
index 321bf5b8b..845aa6671 100644
--- a/sbin/ifconfig/af_inet6.c
+++ b/sbin/ifconfig/af_inet6.c
@@ -485,8 +485,6 @@ static struct cmd inet6_cmds[] = {
 	DEF_CMD("-no_prefer_iface",-ND6_IFF_NO_PREFER_IFACE,setnd6flags),
 	DEF_CMD("no_dad",	ND6_IFF_NO_DAD,		setnd6flags),
 	DEF_CMD("-no_dad",	-ND6_IFF_NO_DAD,	setnd6flags),
-	DEF_CMD("ignoreloop",	ND6_IFF_IGNORELOOP,	setnd6flags),
-	DEF_CMD("-ignoreloop",	-ND6_IFF_IGNORELOOP,	setnd6flags),
 	DEF_CMD_ARG("pltime",        			setip6pltime),
 	DEF_CMD_ARG("vltime",        			setip6vltime),
 	DEF_CMD("eui64",	0,			setip6eui64),
diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index b24b6a042..6152e39cd 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -28,7 +28,7 @@
 .\"     From: @(#)ifconfig.8	8.3 (Berkeley) 1/5/94
 .\" $FreeBSD$
 .\"
-.Dd May 15, 2015
+.Dd July 24, 2015
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -749,15 +749,6 @@ Set a flag to disable Duplicate Address Detection.
 .It Cm -no_dad
 Clear a flag
 .Cm no_dad .
-.It Cm ignoreloop
-Set a flag to disable loopback detection in Enhanced Duplicate Address
-Detection Algorithm.
-When this flag is set,
-Duplicate Address Detection will stop in a finite number of probings
-even if a loopback configuration is detected.
-.It Cm -ignoreloop
-Clear a flag
-.Cm ignoreloop .
 .El
 .Pp
 The following parameters are specific for IPv6 addresses.
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index d664a94f9..7a8368157 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -87,8 +87,7 @@ struct nd_ifinfo {
 #define ND6_IFF_AUTO_LINKLOCAL	0x20
 #define	ND6_IFF_NO_RADR		0x40
 #define ND6_IFF_NO_PREFER_IFACE	0x80 /* XXX: not related to ND. */
-#define ND6_IFF_IGNORELOOP	0x100
-#define ND6_IFF_NO_DAD		0x200
+#define ND6_IFF_NO_DAD		0x100
 
 #define	ND6_CREATE		LLE_CREATE
 #define	ND6_EXCLUSIVE		LLE_EXCLUSIVE
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index d5f40f9ca..2272cd094 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -1450,10 +1450,9 @@ nd6_dad_timer(struct dadq *dp)
 		    dp->dad_ns_lcount > 0 &&
 		    dp->dad_ns_lcount > dp->dad_loopbackprobe) {
 			/*
-			 * A looped back probe is detected,
-			 * Sec. 4.1 in draft-ietf-6man-enhanced-dad-13
-			 * requires transmission of additional probes until
-			 * the loopback condition becomes clear.
+			 * Sec. 4.1 in RFC 7527 requires transmission of
+			 * additional probes until the loopback condition
+			 * becomes clear when a looped back probe is detected.
 			 */
 			log(LOG_ERR, "%s: a looped back NS message is "
 			    "detected during DAD for %s.  "
@@ -1461,16 +1460,6 @@ nd6_dad_timer(struct dadq *dp)
 			    if_name(ifa->ifa_ifp),
 			    ip6_sprintf(ip6buf, IFA_IN6(ifa)));
 			dp->dad_loopbackprobe = dp->dad_ns_lcount;
-			/*
-			 * An interface with IGNORELOOP is one which a
-			 * loopback is permanently expected while regular
-			 * traffic works.  In that case, stop DAD after
-			 * MAX_MULTICAST_SOLICIT number of NS messages
-			 * regardless of the number of received loopback NS
-			 * by increasing dad_loopbackprobe in advance.
-			 */
-			if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IGNORELOOP)
-				dp->dad_loopbackprobe += V_nd6_mmaxtries;
 			/*
 			 * Send an NS immediately and increase dad_count by
 			 * V_nd6_mmaxtries - 1.
-- 
2.45.0