- Implement loopback probing state in enhanced DAD algorithm.

- Add no_dad and ignoreloop per-IF knob.  no_dad disables DAD completely,
  and ignoreloop is to prevent infinite loop in loopback probing state when
  loopback is permanently expected.

3 files changed, 21 insertions, 2 deletions

diff --git a/sbin/ifconfig/af_inet6.c b/sbin/ifconfig/af_inet6.c
index 37494000bc2c..bff66e0d1215 100644
--- a/sbin/ifconfig/af_inet6.c
+++ b/sbin/ifconfig/af_inet6.c
@@ -485,6 +485,10 @@ static struct cmd inet6_cmds[] = {
 	DEF_CMD("-auto_linklocal",-ND6_IFF_AUTO_LINKLOCAL,setnd6flags),
 	DEF_CMD("no_prefer_iface",ND6_IFF_NO_PREFER_IFACE,setnd6flags),
 	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/af_nd6.c b/sbin/ifconfig/af_nd6.c
index b3db0a8204ed..3a510a5576de 100644
--- a/sbin/ifconfig/af_nd6.c
+++ b/sbin/ifconfig/af_nd6.c
@@ -58,7 +58,8 @@ static const char rcsid[] =
 #define	MAX_SYSCTL_TRY	5
 #define	ND6BITS	"\020\001PERFORMNUD\002ACCEPT_RTADV\003PREFER_SOURCE" \
 		"\004IFDISABLED\005DONT_SET_IFROUTE\006AUTO_LINKLOCAL" \
-		"\007NO_RADR\010NO_PREFER_IFACE\020DEFAULTIF"
+		"\007NO_RADR\010NO_PREFER_IFACE\011IGNORELOOP\012NO_DAD" \
+		"\020DEFAULTIF"
 
 static int isnd6defif(int);
 void setnd6flags(const char *, int, int, const struct afswtch *);
diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index fdd398bdb2b6..1e4870dada12 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 December 16, 2014
+.Dd March 6, 2015
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -687,6 +687,20 @@ policy table, configurable with
 .It Cm -no_prefer_iface
 Clear a flag
 .Cm no_prefer_iface .
+.It Cm no_dad
+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.