Add Option RemoveAdvOnExit

Make it configureable if upon shutdown, a final advertisement with zero Router Lifetime is sent . This may need to be disabled ("off") in an vrrp or carp setup.

defaults.h

@@ -49,6 +49,7 @@
 #define DFLT_UnicastOnly 0
 #define DFLT_UnrestrictedUnicast 0
 #define DFLT_AdvRASolicitedUnicast 1
+#define DFLT_RemoveAdvOnExit 1
 
 /* Options sent with RA */
 

gram.y

@@ -77,6 +77,7 @@
 %token		T_AdvDefaultLifetime
 %token		T_AdvDefaultPreference
 %token		T_AdvSourceLLAddress
+%token		T_RemoveAdvOnExit
 
 %token		T_AdvOnLink
 %token		T_AdvAutonomous
@@ -308,6 +309,10 @@ ifaceval	: T_MinRtrAdvInterval NUMBER ';'
 		{
 			iface->ra_header_info.AdvCurHopLimit = $2;
 		}
+		| T_RemoveAdvOnExit SWITCH ';'
+		{
+			iface->RemoveAdvOnExit = $2;
+		}
 		| T_AdvSourceLLAddress SWITCH ';'
 		{
 			iface->AdvSourceLLAddress = $2;

interface.c

@@ -29,6 +29,7 @@ void iface_init_defaults(struct Interface *iface)
 	iface->AdvSendAdvert = DFLT_AdvSendAdv;
 	iface->MaxRtrAdvInterval = DFLT_MaxRtrAdvInterval;
 	iface->AdvSourceLLAddress = DFLT_AdvSourceLLAddress;
+	iface->RemoveAdvOnExit = DFLT_RemoveAdvOnExit;
 	iface->MinDelayBetweenRAs = DFLT_MinDelayBetweenRAs;
 	iface->MinRtrAdvInterval = -1;
 	iface->UnicastOnly = DFLT_UnicastOnly;

radvd.c

@@ -741,7 +741,7 @@ static void kickoff_adverts(int sock, struct Interface *iface)
 
 static void stop_advert_foo(struct Interface *iface, void *data)
 {
-	if (!iface->UnicastOnly) {
+	if (!iface->UnicastOnly && iface->RemoveAdvOnExit) {
 		/* send a final advertisement with zero Router Lifetime */
 		dlog(LOG_DEBUG, 4, "stopping all adverts on %s", iface->props.name);
 		iface->state_info.cease_adv = 1;

radvd.conf.5.man

@@ -338,6 +338,13 @@ included in the RA.
 
 Default: on
 
+.TP
+.BR RemoveAdvOnExit " " on | off
+
+Upon shutdown, send a final advertisement with zero Router Lifetime. This should cause the router and routes to be immediately removed from the receiving end-nodes' route table. This may need to be disabled ("off") in an vrrp or carp setup.
+
+Default: on
+
 .TP
 .BR AdvHomeAgentFlag " " on | off
 

radvd.h

@@ -58,6 +58,7 @@ struct Interface {
 	double MinRtrAdvInterval;
 	double MinDelayBetweenRAs;
 	int AdvSourceLLAddress;
+	int RemoveAdvOnExit;
 	int UnicastOnly;
 	int UnrestrictedUnicast;
 	int AdvRASolicitedUnicast;

scanner.l

@@ -67,6 +67,7 @@ AdvCurHopLimit		{ return T_AdvCurHopLimit; }
 AdvDefaultLifetime	{ return T_AdvDefaultLifetime; }
 AdvDefaultPreference	{ return T_AdvDefaultPreference; }
 AdvSourceLLAddress	{ return T_AdvSourceLLAddress; }
+RemoveAdvOnExit		{ return T_RemoveAdvOnExit; }
 
 AdvOnLink		{ return T_AdvOnLink; }
 AdvAutonomous		{ return T_AdvAutonomous; }