- The DHCP Relay Agent Information Option / Link Selection Sub-Option

  is now supported.  (See RFC3527 for details). [ISC-Bugs #16251]

4 files changed, 19 insertions, 7 deletions

diff --git a/RELNOTES b/RELNOTES
index b4b3266f..e6247cc6 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -119,6 +119,9 @@ and for prodding me into improving it.
   lease.  Instead, they happen on a schedule.  See 'man dhcpd.conf' for the
   min-balance and max-balance statements for more information.
 
+- The DHCP Relay Agent Information Option / Link Selection Sub-Option
+  is now supported.  (See RFC3527 for details).
+
 			Changes since 3.0.4
 
 - A warning that host statements declared within subnet or shared-network
diff --git a/includes/dhcp.h b/includes/dhcp.h
index cb4ac5ab..abdb8549 100644
--- a/includes/dhcp.h
+++ b/includes/dhcp.h
@@ -174,6 +174,7 @@ struct dhcp_packet {
 #define RAI_CIRCUIT_ID	1
 #define RAI_REMOTE_ID	2
 #define RAI_AGENT_ID	3
+#define RAI_LINK_SELECT	5
 
 /* FQDN suboptions: */
 #define FQDN_NO_CLIENT_UPDATE		1
diff --git a/server/dhcp.c b/server/dhcp.c
index f9c71e95..ff3db528 100644
--- a/server/dhcp.c
+++ b/server/dhcp.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dhcp.c,v 1.207 2006/06/19 20:39:28 shane Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: dhcp.c,v 1.208 2006/07/17 15:16:43 dhankins Exp $ Copyright (c) 2004-2006 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -3902,9 +3902,15 @@ int locate_network (packet)
 	struct subnet *subnet = (struct subnet *)0;
 	struct option_cache *oc;
 
-	/* See if there's a subnet selection option. */
-	oc = lookup_option (&dhcp_universe, packet -> options,
-			    DHO_SUBNET_SELECTION);
+	/* See if there's a Relay Agent Link Selection Option, or a
+	 * Subnet Selection Option.  The Link-Select and Subnet-Select
+	 * are formatted and used precisely the same, but we must prefer
+	 * the link-select over the subnet-select.
+	 */
+	if ((oc = lookup_option(&agent_universe, packet->options,
+				RAI_LINK_SELECT)) == NULL)
+		oc = lookup_option(&dhcp_universe, packet->options,
+				   DHO_SUBNET_SELECTION);
 
 	/* If there's no SSO and no giaddr, then use the shared_network
 	   from the interface, if there is one.   If not, fail. */
@@ -3918,8 +3924,9 @@ int locate_network (packet)
 		return 0;
 	}
 
-	/* If there's an SSO, and it's valid, use it to figure out the
-	   subnet.    If it's not valid, fail. */
+	/* If there's an option indicating link connection, and it's valid,
+	 * use it to figure out the subnet.  If it's not valid, fail.
+	 */
 	if (oc) {
 		memset (&data, 0, sizeof data);
 		if (!evaluate_option_cache (&data, packet, (struct lease *)0,
diff --git a/server/stables.c b/server/stables.c
index 5f83df49..7c7df5ca 100644
--- a/server/stables.c
+++ b/server/stables.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: stables.c,v 1.30 2006/06/15 17:49:49 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: stables.c,v 1.31 2006/07/17 15:16:43 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -178,6 +178,7 @@ static struct option agent_options[] = {
 	{ "remote-id", "X",			&agent_universe,   2, 1 },
 	{ "agent-id", "I",			&agent_universe,   3, 1 },
 	{ "DOCSIS-device-class", "L",		&agent_universe,   4, 1 },
+	{ "link-selection", "I",		&agent_universe,   5, 1 },
 	{ NULL, NULL, NULL, 0, 0 }
 };