If the new 'parent' keyword is specified for a host in a table,

inherit the state from another host with the specified Id; no
additional check will be for the inheriting host.  This helps in
scenarios with lots of IP aliases that all point to the same service
on the same host (like web hosting with many SSL domains).

discussed with pyr, tested in different setups

7 files changed, 114 insertions, 37 deletions

diff --git a/usr.sbin/relayd/check_icmp.c b/usr.sbin/relayd/check_icmp.c
index f16e9bd3d61..c022077f936 100644
--- a/usr.sbin/relayd/check_icmp.c
+++ b/usr.sbin/relayd/check_icmp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: check_icmp.c,v 1.23 2008/01/31 09:33:39 reyk Exp $	*/
+/*	$OpenBSD: check_icmp.c,v 1.24 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -197,7 +197,8 @@ send_icmp(int s, short event, void *arg)
 		    table->conf.flags & F_DISABLE)
 			continue;
 		TAILQ_FOREACH(host, &table->hosts, entry) {
-			if (host->flags & (F_DISABLE | F_CHECK_SENT))
+			if (host->flags & (F_DISABLE | F_CHECK_SENT) ||
+			    host->conf.parentid)
 				continue;
 			if (((struct sockaddr *)&host->conf.ss)->sa_family !=
 			    cie->af)
diff --git a/usr.sbin/relayd/control.c b/usr.sbin/relayd/control.c
index d0c7258fe7d..67be0a1a7be 100644
--- a/usr.sbin/relayd/control.c
+++ b/usr.sbin/relayd/control.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.25 2008/01/31 09:33:39 reyk Exp $	*/
+/*	$OpenBSD: control.c,v 1.26 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -293,7 +293,7 @@ control_dispatch_imsg(int fd, short event, void *arg)
 			if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id))
 				fatalx("invalid imsg header len");
 			memcpy(&id, imsg.data, sizeof(id));
-			if (disable_host(c, &id))
+			if (disable_host(c, &id, NULL))
 				imsg_compose(&c->ibuf, IMSG_CTL_FAIL, 0, 0, -1,
 				    NULL, 0);
 			else {
@@ -307,7 +307,7 @@ control_dispatch_imsg(int fd, short event, void *arg)
 			if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id))
 				fatalx("invalid imsg header len");
 			memcpy(&id, imsg.data, sizeof(id));
-			if (enable_host(c, &id))
+			if (enable_host(c, &id, NULL))
 				imsg_compose(&c->ibuf, IMSG_CTL_FAIL, 0, 0, -1,
 				    NULL, 0);
 			else {
diff --git a/usr.sbin/relayd/hce.c b/usr.sbin/relayd/hce.c
index f0cd92cfb47..262f7f646c9 100644
--- a/usr.sbin/relayd/hce.c
+++ b/usr.sbin/relayd/hce.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hce.c,v 1.41 2008/03/12 10:50:44 pyr Exp $	*/
+/*	$OpenBSD: hce.c,v 1.42 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -240,7 +240,7 @@ hce_launch_checks(int fd, short event, void *arg)
 			fatalx("hce_launch_checks: unknown check type");
 
 		TAILQ_FOREACH(host, &table->hosts, entry) {
-			if (host->flags & F_DISABLE)
+			if (host->flags & F_DISABLE || host->conf.parentid)
 				continue;
 			switch (table->conf.check) {
 			case CHECK_ICMP:
@@ -276,6 +276,10 @@ hce_notify_done(struct host *host, const char *msg)
 	struct timeval		 tv_now, tv_dur;
 	u_long			 duration;
 	u_int			 logopt;
+	struct host		*h;
+	int			 hostup;
+
+	hostup = host->up;
 
 	if (host->up == HOST_DOWN && host->retry_cnt) {
 		log_debug("hce_notify_done: host %s retry %d",
@@ -327,6 +331,15 @@ hce_notify_done(struct host *host, const char *msg)
 		snmp_hosttrap(table, host);
 
 	host->last_up = host->up;
+
+	if (TAILQ_EMPTY(&host->children))
+		return;
+
+	/* Notify for all other hosts that inherit the state from this one */
+	TAILQ_FOREACH(h, &host->children, child) {
+		h->up = hostup;		
+		hce_notify_done(h, msg);
+	}
 }
 
 void
diff --git a/usr.sbin/relayd/parse.y b/usr.sbin/relayd/parse.y
index 3c7cb2b61a7..9a881ed0f2a 100644
--- a/usr.sbin/relayd/parse.y
+++ b/usr.sbin/relayd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.119 2008/07/17 16:41:06 reyk Exp $	*/
+/*	$OpenBSD: parse.y,v 1.120 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2007, 2008 Reyk Floeter <reyk@openbsd.org>
@@ -130,11 +130,11 @@ typedef struct {
 %token	ON PATH PORT PREFORK PROTO QUERYSTR REAL REDIRECT RELAY REMOVE TRAP
 %token	REQUEST RESPONSE RETRY RETURN ROUNDROBIN SACK SCRIPT SEND SESSION
 %token	SOCKET SSL STICKYADDR STYLE TABLE TAG TCP TIMEOUT TO UPDATES URL
-%token	VIRTUAL WITH ERROR ROUTE TRANSPARENT
+%token	VIRTUAL WITH ERROR ROUTE TRANSPARENT PARENT
 %token	<v.string>	STRING
 %token  <v.number>	NUMBER
 %type	<v.string>	interface hostname table
-%type	<v.number>	port http_type loglevel sslcache optssl mark
+%type	<v.number>	port http_type loglevel sslcache optssl mark parent
 %type	<v.number>	proto_type dstmode retry log flag direction forwardmode
 %type	<v.host>	host
 %type	<v.tv>		timeout
@@ -1238,7 +1238,7 @@ interface	: /*empty*/		{ $$ = NULL; }
 		| INTERFACE STRING	{ $$ = $2; }
 		;
 
-host		: STRING retry		{
+host		: STRING retry parent	{
 			struct address *a;
 			struct addresslist al;
 
@@ -1266,6 +1266,8 @@ host		: STRING retry		{
 			free($1);
 			$$->conf.id = 0; /* will be set later */
 			$$->conf.retry = $2;
+			$$->conf.parentid = $3;
+			TAILQ_INIT(&$$->children);
 		}
 		;
 
@@ -1278,6 +1280,15 @@ retry		: /* nothing */		{ $$ = 0; }
 		}
 		;
 
+parent		: /* nothing */		{ $$ = 0; }
+		| PARENT NUMBER		{
+			if (($$ = $2) < 0) {
+				yyerror("invalid parent value: %d\n", $2);
+				YYERROR;
+			}
+		}
+		;
+
 timeout		: NUMBER
 		{
 			if ($1 < 0) {
@@ -1378,6 +1389,7 @@ lookup(char *s)
 		{ "nodelay",		NODELAY },
 		{ "nothing",		NOTHING },
 		{ "on",			ON },
+		{ "parent",		PARENT },
 		{ "path",		PATH },
 		{ "port",		PORT },
 		{ "prefork",		PREFORK },
@@ -1729,7 +1741,7 @@ parse_config(const char *filename, int opts)
 {
 	struct sym	*sym, *next;
 	struct table	*nexttb;
-	struct host	*h;
+	struct host	*h, *ph;
 
 	if ((conf = calloc(1, sizeof(*conf))) == NULL ||
 	    (conf->sc_tables = calloc(1, sizeof(*conf->sc_tables))) == NULL ||
@@ -1833,6 +1845,26 @@ parse_config(const char *filename, int opts)
 			free(table);
 			continue;
 		}
+
+		TAILQ_FOREACH(h, &table->hosts, entry) {
+			if (h->conf.parentid) {
+				ph = host_find(conf, h->conf.parentid);
+
+				/* Validate the parent id */
+				if (h->conf.id == h->conf.parentid ||
+				    ph == NULL || ph->conf.parentid)
+					ph = NULL;
+
+				if (ph == NULL) {
+					log_warnx("host parent id %d invalid",
+					    h->conf.parentid);
+					errors++;
+				} else
+					TAILQ_INSERT_TAIL(&ph->children,
+					    h, child);
+			}
+		}
+
 		if (!(table->conf.flags & F_USED)) {
 			log_warnx("unused table: %s", table->conf.name);
 			errors++;
@@ -2135,6 +2167,7 @@ table_inherit(struct table *tb)
 		}
 		h->conf.tableid = tb->conf.id;
 		h->tablename = tb->conf.name;
+		TAILQ_INIT(&h->children);
 		TAILQ_INSERT_TAIL(&tb->hosts, h, entry);
 	}
 
diff --git a/usr.sbin/relayd/pfe.c b/usr.sbin/relayd/pfe.c
index f905f4f85d9..f06432a6b6b 100644
--- a/usr.sbin/relayd/pfe.c
+++ b/usr.sbin/relayd/pfe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pfe.c,v 1.48 2008/01/31 09:56:28 reyk Exp $	*/
+/*	$OpenBSD: pfe.c,v 1.49 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2006 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -749,18 +749,20 @@ enable_table(struct ctl_conn *c, struct ctl_id *id)
 }
 
 int
-disable_host(struct ctl_conn *c, struct ctl_id *id)
+disable_host(struct ctl_conn *c, struct ctl_id *id, struct host *host)
 {
-	struct host	*host;
+	struct host	*h;
 	struct table	*table;
 	int		 n;
 
-	if (id->id == EMPTY_ID)
-		host = host_findbyname(env, id->name);
-	else
-		host = host_find(env, id->id);
-	if (host == NULL)
-		return (-1);
+	if (host == NULL) {
+		if (id->id == EMPTY_ID)
+			host = host_findbyname(env, id->name);
+		else
+			host = host_find(env, id->id);
+		if (host == NULL || host->conf.parentid)
+			return (-1);
+	}
 	id->id = host->conf.id;
 
 	if (host->flags & F_DISABLE)
@@ -788,22 +790,30 @@ disable_host(struct ctl_conn *c, struct ctl_id *id)
 		    IMSG_HOST_DISABLE, 0, 0, -1,
 		    &host->conf.id, sizeof(host->conf.id));
 	log_debug("disable_host: disabled host %d", host->conf.id);
-	pfe_sync();
+
+	/* Disable all children */
+	TAILQ_FOREACH(h, &host->children, child)
+		disable_host(c, id, h);
+
+	if (!host->conf.parentid)
+		pfe_sync();
 	return (0);
 }
 
 int
-enable_host(struct ctl_conn *c, struct ctl_id *id)
+enable_host(struct ctl_conn *c, struct ctl_id *id, struct host *host)
 {
-	struct host	*host;
+	struct host	*h;
 	int		 n;
 
-	if (id->id == EMPTY_ID)
-		host = host_findbyname(env, id->name);
-	else
-		host = host_find(env, id->id);
-	if (host == NULL)
-		return (-1);
+	if (host == NULL) {
+		if (id->id == EMPTY_ID)
+			host = host_findbyname(env, id->name);
+		else
+			host = host_find(env, id->id);
+		if (host == NULL || host->conf.parentid)
+			return (-1);
+	}
 	id->id = host->conf.id;
 
 	if (!(host->flags & F_DISABLE))
@@ -822,7 +832,13 @@ enable_host(struct ctl_conn *c, struct ctl_id *id)
 		    IMSG_HOST_ENABLE, 0, 0, -1,
 		    &host->conf.id, sizeof(host->conf.id));
 	log_debug("enable_host: enabled host %d", host->conf.id);
-	pfe_sync();
+
+	/* Enable all children */
+	TAILQ_FOREACH(h, &host->children, child)
+		enable_host(c, id, h);
+
+	if (!host->conf.parentid)
+		pfe_sync();
 	return (0);
 }
 
diff --git a/usr.sbin/relayd/relayd.conf.5 b/usr.sbin/relayd/relayd.conf.5
index 16c609b0f69..2611a531000 100644
--- a/usr.sbin/relayd/relayd.conf.5
+++ b/usr.sbin/relayd/relayd.conf.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: relayd.conf.5,v 1.88 2008/06/11 18:21:20 reyk Exp $
+.\"	$OpenBSD: relayd.conf.5,v 1.89 2008/07/19 10:52:32 reyk Exp $
 .\"
 .\" Copyright (c) 2006, 2007 Reyk Floeter <reyk@openbsd.org>
 .\" Copyright (c) 2006, 2007 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: June 11 2008 $
+.Dd $Mdocdate: July 19 2008 $
 .Dt RELAYD.CONF 5
 .Os
 .Sh NAME
@@ -183,7 +183,7 @@ The table can be later enabled through
 .El
 Each table must contain at least one host;
 multiple hosts are separated by newline, comma, or whitespace.
-Host entries may be defined with the following attribute:
+Host entries may be defined with the following attributes:
 .Bl -tag -width retry
 .It Ic retry Ar number
 The optional retry option adds a tolerance for failed host checks;
@@ -192,6 +192,17 @@ the check will be retried for
 more times before setting the host state to down.
 If this table is used by a relay, it will also specify the number of
 retries for outgoing connection attempts.
+.It Ic parent Ar number
+The optional parent option allows to inherit the state from a parent
+host with the specified identifier.
+The check will be skipped for this host and copied from the parent host.
+This can be used to prevent multiple checks on hosts with multiple IP
+addresses for the same service.
+The host identifiers are sequentially assigned to the configured hosts
+starting with 1; it can be figured out with the
+.Xr relayctl 8
+.Ic show summary
+commands.
 .El
 .Pp
 For example:
diff --git a/usr.sbin/relayd/relayd.h b/usr.sbin/relayd/relayd.h
index 1979e4285fa..763a4f58709 100644
--- a/usr.sbin/relayd/relayd.h
+++ b/usr.sbin/relayd/relayd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: relayd.h,v 1.106 2008/07/09 17:16:51 reyk Exp $	*/
+/*	$OpenBSD: relayd.h,v 1.107 2008/07/19 10:52:32 reyk Exp $	*/
 
 /*
  * Copyright (c) 2006, 2007 Pierre-Yves Ritschard <pyr@openbsd.org>
@@ -345,6 +345,7 @@ enum forwardmode {
 
 struct host_config {
 	objid_t			 id;
+	objid_t			 parentid;
 	objid_t			 tableid;
 	int			 retry;
 	char			 name[MAXHOSTNAMELEN];
@@ -353,6 +354,8 @@ struct host_config {
 
 struct host {
 	TAILQ_ENTRY(host)	 entry;
+	TAILQ_ENTRY(host)	 child;
+	TAILQ_HEAD(,host)	 children;
 	struct host_config	 conf;
 	u_int32_t		 flags;
 	char			*tablename;
@@ -766,10 +769,10 @@ void	 show(struct ctl_conn *);
 void	 show_sessions(struct ctl_conn *);
 int	 enable_rdr(struct ctl_conn *, struct ctl_id *);
 int	 enable_table(struct ctl_conn *, struct ctl_id *);
-int	 enable_host(struct ctl_conn *, struct ctl_id *);
+int	 enable_host(struct ctl_conn *, struct ctl_id *, struct host *);
 int	 disable_rdr(struct ctl_conn *, struct ctl_id *);
 int	 disable_table(struct ctl_conn *, struct ctl_id *);
-int	 disable_host(struct ctl_conn *, struct ctl_id *);
+int	 disable_host(struct ctl_conn *, struct ctl_id *, struct host *);
 
 /* pfe_filter.c */
 void	 init_filter(struct relayd *);