implement support for fast hello packets.

if route-dead-time is set to "minimal" (rather than a number of
seconds), the dead time is set to 1 second and hellos are sent at
the interval specified by fast-hello-interval in msecs. this is non
standard wrt to the ospf rfc, but it does interoperate with at least
one other router vendor.

this allows much better responsiveness to l3 topology changes than
the standard intervals allow. if i yank a cable to one of my
upstreams, the routes adjust in a second rather than the default
of 40 i was running with before. the users dont even notice something
changed.

developed while working with joshua atterbury.
ok claudio@ as part of a larger diff.
dedicated to zan rowe who thinks she is a bigger nerd than me.

6 files changed, 81 insertions, 23 deletions

diff --git a/usr.sbin/ospfd/interface.c b/usr.sbin/ospfd/interface.c
index a5d53ab9b0a..92a9e6f1ee2 100644
--- a/usr.sbin/ospfd/interface.c
+++ b/usr.sbin/ospfd/interface.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: interface.c,v 1.66 2009/09/30 14:39:07 claudio Exp $ */
+/*	$OpenBSD: interface.c,v 1.67 2010/02/16 08:39:05 dlg Exp $ */
 
 /*
  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
@@ -278,7 +278,10 @@ if_hello_timer(int fd, short event, void *arg)
 
 	/* reschedule hello_timer */
 	timerclear(&tv);
-	tv.tv_sec = iface->hello_interval;
+	if (iface->dead_interval == FAST_RTR_DEAD_TIME)
+		tv.tv_usec = iface->fast_hello_interval * 1000;
+	else
+		tv.tv_sec = iface->hello_interval;
 	if (evtimer_add(&iface->hello_timer, &tv) == -1)
 		fatal("if_hello_timer");
 }
@@ -629,6 +632,7 @@ if_to_ctl(struct iface *iface)
 	ictl.adj_cnt = 0;
 	ictl.baudrate = iface->baudrate;
 	ictl.dead_interval = iface->dead_interval;
+	ictl.fast_hello_interval = iface->fast_hello_interval;
 	ictl.transmit_delay = iface->transmit_delay;
 	ictl.hello_interval = iface->hello_interval;
 	ictl.flags = iface->flags;
@@ -645,9 +649,10 @@ if_to_ctl(struct iface *iface)
 	gettimeofday(&now, NULL);
 	if (evtimer_pending(&iface->hello_timer, &tv)) {
 		timersub(&tv, &now, &res);
-		ictl.hello_timer = res.tv_sec;
-	} else
-		ictl.hello_timer = -1;
+		ictl.hello_timer = res;
+	} else {
+		ictl.hello_timer.tv_sec = -1;
+	}
 
 	if (iface->state != IF_STA_DOWN) {
 		ictl.uptime = now.tv_sec - iface->uptime;
diff --git a/usr.sbin/ospfd/ospf.h b/usr.sbin/ospfd/ospf.h
index cb950898a61..1bddb36de20 100644
--- a/usr.sbin/ospfd/ospf.h
+++ b/usr.sbin/ospfd/ospf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospf.h,v 1.17 2010/02/16 08:22:42 dlg Exp $ */
+/*	$OpenBSD: ospf.h,v 1.18 2010/02/16 08:39:05 dlg Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -44,7 +44,13 @@
 #define MIN_HELLO_INTERVAL	1
 #define MAX_HELLO_INTERVAL	65535
 
+/* msec */
+#define DEFAULT_FAST_INTERVAL	333
+#define MIN_FAST_INTERVAL	50
+#define MAX_FAST_INTERVAL	333
+
 #define DEFAULT_RTR_DEAD_TIME	40
+#define FAST_RTR_DEAD_TIME	1
 #define MIN_RTR_DEAD_TIME	2
 #define MAX_RTR_DEAD_TIME	2147483647
 
diff --git a/usr.sbin/ospfd/ospfd.conf.5 b/usr.sbin/ospfd/ospfd.conf.5
index 51c9140f298..4e23bd9a01a 100644
--- a/usr.sbin/ospfd/ospfd.conf.5
+++ b/usr.sbin/ospfd/ospfd.conf.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ospfd.conf.5,v 1.41 2010/02/16 08:27:31 dlg Exp $
+.\"	$OpenBSD: ospfd.conf.5,v 1.42 2010/02/16 08:39:05 dlg Exp $
 .\"
 .\" Copyright (c) 2005 Esben Norby <norby@openbsd.org>
 .\" Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
@@ -341,6 +341,11 @@ demotion counter by 1 on the given interface group, usually
 when the interface state is going down.
 The demotion counter will be decreased when the interface
 state is active again.
+.It Ic fast-hello-interval Ic msec Ar microseconds
+If the interface is configured to use
+.Ic router-dead-time minimal ,
+hello packets will be sent using this timer.
+The default value is 333; valid range is 50\-333 microseconds.
 .It Ic hello-interval Ar seconds
 Set the hello interval.
 The default value is 10; valid range is 1\-65535 seconds.
@@ -353,9 +358,17 @@ The specified interface will be announced as a stub network.
 .It Ic retransmit-interval Ar seconds
 Set retransmit interval.
 The default value is 5 seconds; valid range is 5\-3600 seconds.
-.It Ic router-dead-time Ar seconds
+.It Xo
+.Ic router-dead-time
+.Po Ar seconds Ns \&| Ns Ic minimal Pc
+.Xc
 Set the router dead time, a.k.a. neighbor inactivity timer.
 The default value is 40 seconds; valid range is 2\-2147483647 seconds.
+If the router dead time has been set to
+.Ic minimal ,
+the timer is set to 1 second and hello packets are sent using the interval
+specified by
+.Ic fast-hello-interval .
 When a neighbor has been
 inactive for router-dead-time its state is set to DOWN.
 Neighbors
diff --git a/usr.sbin/ospfd/ospfd.h b/usr.sbin/ospfd/ospfd.h
index 0e52b2394a4..4d3ba0fba01 100644
--- a/usr.sbin/ospfd/ospfd.h
+++ b/usr.sbin/ospfd/ospfd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfd.h,v 1.84 2009/11/02 20:20:54 claudio Exp $ */
+/*	$OpenBSD: ospfd.h,v 1.85 2010/02/16 08:39:05 dlg Exp $ */
 
 /*
  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
@@ -322,6 +322,7 @@ struct iface {
 
 	u_int64_t		 baudrate;
 	u_int32_t		 dead_interval;
+	u_int32_t		 fast_hello_interval;
 	u_int32_t		 ls_ack_cnt;
 	u_int32_t		 crypt_seq_num;
 	time_t			 uptime;
@@ -434,10 +435,11 @@ struct ctl_iface {
 	struct in_addr		 dr_addr;
 	struct in_addr		 bdr_id;
 	struct in_addr		 bdr_addr;
-	time_t			 hello_timer;
+	struct timeval		 hello_timer;
 	time_t			 uptime;
 	u_int64_t		 baudrate;
 	u_int32_t		 dead_interval;
+	u_int32_t		 fast_hello_interval;
 	unsigned int		 ifindex;
 	int			 state;
 	int			 mtu;
diff --git a/usr.sbin/ospfd/parse.y b/usr.sbin/ospfd/parse.y
index c26ac5fa290..93a3518969d 100644
--- a/usr.sbin/ospfd/parse.y
+++ b/usr.sbin/ospfd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.69 2010/02/16 08:22:42 dlg Exp $ */
+/*	$OpenBSD: parse.y,v 1.70 2010/02/16 08:39:05 dlg Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -87,6 +87,7 @@ struct config_defaults {
 	char		auth_key[MAX_SIMPLE_AUTH_LEN];
 	struct auth_md_head	 md_list;
 	u_int32_t	dead_interval;
+	u_int32_t	fast_hello_interval;
 	u_int16_t	transmit_delay;
 	u_int16_t	hello_interval;
 	u_int16_t	rxmt_interval;
@@ -119,17 +120,18 @@ typedef struct {
 %token	RFC1583COMPAT STUB ROUTER SPFDELAY SPFHOLDTIME EXTTAG
 %token	AUTHKEY AUTHTYPE AUTHMD AUTHMDKEYID
 %token	METRIC PASSIVE
-%token	HELLOINTERVAL TRANSMITDELAY
+%token	HELLOINTERVAL FASTHELLOINTERVAL TRANSMITDELAY
 %token	RETRANSMITINTERVAL ROUTERDEADTIME ROUTERPRIORITY
 %token	SET TYPE
 %token	YES NO
-%token	MSEC
+%token	MSEC MINIMAL
 %token	DEMOTE
 %token	INCLUDE
 %token	ERROR
 %token	<v.string>	STRING
 %token	<v.number>	NUMBER
 %type	<v.number>	yesno no optlist optlist_l option demotecount msec
+%type	<v.number>	deadtime
 %type	<v.string>	string
 %type	<v.redist>	redistribute
 
@@ -449,12 +451,7 @@ defaults	: METRIC NUMBER {
 			}
 			defs->priority = $2;
 		}
-		| ROUTERDEADTIME NUMBER {
-			if ($2 < MIN_RTR_DEAD_TIME || $2 > MAX_RTR_DEAD_TIME) {
-				yyerror("router-dead-time out of range (%d-%d)",
-				    MIN_RTR_DEAD_TIME, MAX_RTR_DEAD_TIME);
-				YYERROR;
-			}
+		| ROUTERDEADTIME deadtime {
 			defs->dead_interval = $2;
 		}
 		| TRANSMITDELAY NUMBER {
@@ -475,6 +472,16 @@ defaults	: METRIC NUMBER {
 			}
 			defs->hello_interval = $2;
 		}
+		| FASTHELLOINTERVAL MSEC NUMBER {
+			if ($3 < MIN_FAST_INTERVAL ||
+			    $3 > MAX_FAST_INTERVAL) {
+				yyerror("fast-hello-interval msec out of "
+				    "range (%d-%d)", MIN_FAST_INTERVAL,
+				    MAX_FAST_INTERVAL);
+				YYERROR;
+			}
+			defs->fast_hello_interval = $3;
+		}
 		| RETRANSMITINTERVAL NUMBER {
 			if ($2 < MIN_RXMT_INTERVAL || $2 > MAX_RXMT_INTERVAL) {
 				yyerror("retransmit-interval out of range "
@@ -490,6 +497,18 @@ defaults	: METRIC NUMBER {
 		| authmd
 		;
 
+deadtime	: NUMBER {
+			if ($1 < MIN_RTR_DEAD_TIME || $1 > MAX_RTR_DEAD_TIME) {
+				yyerror("router-dead-time out of range (%d-%d)",
+				    MIN_RTR_DEAD_TIME, MAX_RTR_DEAD_TIME);
+				YYERROR;
+			}
+			$$ = $1;
+		}
+		| MINIMAL {
+			$$ = FAST_RTR_DEAD_TIME;
+		}
+
 optnl		: '\n' optnl
 		|
 		;
@@ -613,8 +632,12 @@ interface	: INTERFACE STRING	{
 			defs = &ifacedefs;
 		} interface_block {
 			iface->dead_interval = defs->dead_interval;
+			iface->fast_hello_interval = defs->fast_hello_interval;
 			iface->transmit_delay = defs->transmit_delay;
-			iface->hello_interval = defs->hello_interval;
+			if (iface->dead_interval == FAST_RTR_DEAD_TIME)
+				iface->hello_interval = 0;
+			else
+				iface->hello_interval = defs->hello_interval;
 			iface->rxmt_interval = defs->rxmt_interval;
 			iface->metric = defs->metric;
 			iface->priority = defs->priority;
@@ -699,10 +722,12 @@ lookup(char *s)
 		{"demote",		DEMOTE},
 		{"external-tag",	EXTTAG},
 		{"fib-update",		FIBUPDATE},
+		{"fast-hello-interval",	FASTHELLOINTERVAL},
 		{"hello-interval",	HELLOINTERVAL},
 		{"include",		INCLUDE},
 		{"interface",		INTERFACE},
 		{"metric",		METRIC},
+		{"minimal",		MINIMAL},
 		{"msec",		MSEC},
 		{"no",			NO},
 		{"passive",		PASSIVE},
@@ -1055,6 +1080,7 @@ parse_config(char *filename, int opts)
 	defs = &globaldefs;
 	TAILQ_INIT(&defs->md_list);
 	defs->dead_interval = DEFAULT_RTR_DEAD_TIME;
+	defs->fast_hello_interval = DEFAULT_FAST_INTERVAL;
 	defs->transmit_delay = DEFAULT_TRANSMIT_DELAY;
 	defs->hello_interval = DEFAULT_HELLO_INTERVAL;
 	defs->rxmt_interval = DEFAULT_RXMT_INTERVAL;
diff --git a/usr.sbin/ospfd/printconf.c b/usr.sbin/ospfd/printconf.c
index 0b2b65b54cf..a99efa484ea 100644
--- a/usr.sbin/ospfd/printconf.c
+++ b/usr.sbin/ospfd/printconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: printconf.c,v 1.14 2010/02/16 08:22:42 dlg Exp $ */
+/*	$OpenBSD: printconf.c,v 1.15 2010/02/16 08:39:05 dlg Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -115,7 +115,6 @@ print_iface(struct iface *iface)
 
 	printf("\tinterface %s:%s {\n", iface->name, inet_ntoa(iface->addr));
 
-	printf("\t\thello-interval %d\n", iface->hello_interval);
 	printf("\t\tmetric %d\n", iface->metric);
 
 	if (iface->passive)
@@ -124,7 +123,14 @@ print_iface(struct iface *iface)
 		printf("\t\tdemote %s\n", iface->demote_group);
 
 	printf("\t\tretransmit-interval %d\n", iface->rxmt_interval);
-	printf("\t\trouter-dead-time %d\n", iface->dead_interval);
+	if (iface->dead_interval == FAST_RTR_DEAD_TIME) {
+		printf("\t\trouter-dead-time minimal\n");
+		printf("\t\tfast-hello-interval msec %u\n",
+		    iface->fast_hello_interval);
+	} else {
+		printf("\t\trouter-dead-time %d\n", iface->dead_interval);
+		printf("\t\thello-interval %d\n", iface->hello_interval);
+	}
 	printf("\t\trouter-priority %d\n", iface->priority);
 	printf("\t\ttransmit-delay %d\n", iface->transmit_delay);