diff -up dhcp-4.3.5b1/common/options.c.option97 dhcp-4.3.5b1/common/options.c

--- dhcp-4.3.5b1/common/options.c.option97	2016-09-12 17:17:13.972691041 +0200

+++ dhcp-4.3.5b1/common/options.c	2016-09-12 17:19:17.706790276 +0200

@@ -4434,13 +4434,26 @@ int validate_packet(struct packet *packe

 				"a future version of ISC DHCP will reject this");

 		}

 	} else {

-		/*

-		 * If hlen is 0 we don't have any identifier, we warn the user

-		 * but continue processing the packet as we can.

-		 */

-		if (packet->raw->hlen == 0) {

-			log_debug("Received DHCPv4 packet without client-id"

-				  " option and empty hlen field.");

+		oc = lookup_option (&dhcp_universe, packet->options,

+				    DHO_PXE_CLIENT_ID);

+		if (oc) {

+			/* Let's check if pxe-client-id is sane */

+			if ((oc->data.len < 2) ||

+			    (oc->data.data[0] == '\0' &&

+			     oc->data.len != 17)) {

+				log_debug("Dropped DHCPv4 packet with wrong "

+				    "(len == %d) pxe-client-id", oc->data.len);

+				return (0);

+			}

+		} else {

+			/*

+			 * If hlen is 0 we don't have any identifier, we warn the user

+			 * but continue processing the packet as we can.

+			 */

+			if (packet->raw->hlen == 0) {

+				log_debug("Received DHCPv4 packet without client-id"

+						" option and empty hlen field.");

+			}

 		}

 	}

diff -up dhcp-4.3.5b1/common/tables.c.option97 dhcp-4.3.5b1/common/tables.c

--- dhcp-4.3.5b1/common/tables.c.option97	2016-09-12 17:17:13.927691005 +0200

+++ dhcp-4.3.5b1/common/tables.c	2016-09-12 17:17:13.972691041 +0200

@@ -196,8 +196,9 @@ static struct option dhcp_options[] = {

 	/* Defined by RFC 4578 */

 	{ "pxe-system-type", "S",		&dhcp_universe,  93, 1 },

 	{ "pxe-interface-id", "BBB",		&dhcp_universe,  94, 1 },

-	{ "pxe-client-id", "BX",		&dhcp_universe,  97, 1 },

 #endif

+	{ "pxe-client-id", "BX",		&dhcp_universe,  97, 1 },

+

 	{ "uap-servers", "t",			&dhcp_universe,  98, 1 },

 #if defined(RFC4776_OPTIONS)

         { "geoconf-civic", "X",                 &dhcp_universe, 99, 1 },

diff -up dhcp-4.3.5b1/includes/dhcp.h.option97 dhcp-4.3.5b1/includes/dhcp.h

--- dhcp-4.3.5b1/includes/dhcp.h.option97	2016-09-12 17:17:13.936691013 +0200

+++ dhcp-4.3.5b1/includes/dhcp.h	2016-09-12 17:17:13.972691041 +0200

@@ -159,6 +159,7 @@ struct dhcp_packet {

 #define DHO_AUTHENTICATE			90  /* RFC3118, was 210 */

 #define DHO_CLIENT_LAST_TRANSACTION_TIME	91

 #define DHO_ASSOCIATED_IP			92

+#define DHO_PXE_CLIENT_ID			97  /* RFC4578 */

 #define DHO_SUBNET_SELECTION			118 /* RFC3011! */

 #define DHO_DOMAIN_SEARCH			119 /* RFC3397 */

 #define DHO_CLASSLESS_STATIC_ROUTES		121 /* RFC3442 */

diff -up dhcp-4.3.5b1/server/dhcp.c.option97 dhcp-4.3.5b1/server/dhcp.c

--- dhcp-4.3.5b1/server/dhcp.c.option97	2016-09-12 17:17:13.947691021 +0200

+++ dhcp-4.3.5b1/server/dhcp.c	2016-09-12 17:17:13.973691042 +0200

@@ -221,6 +221,10 @@ dhcp (struct packet *packet) {

 			oc = lookup_option (&dhcp_universe, packet -> options,

 					    DHO_DHCP_CLIENT_IDENTIFIER);

 			if (!oc)

+				oc = lookup_option (&dhcp_universe,

+						    packet -> options,

+						    DHO_PXE_CLIENT_ID);

+			if (!oc)

 				goto nolease;

 			memset (&data, 0, sizeof data);

@@ -818,6 +822,9 @@ void dhcprelease (packet, ms_nulltp)

 	oc = lookup_option (&dhcp_universe, packet -> options,

 			    DHO_DHCP_CLIENT_IDENTIFIER);

+	if (!oc)

+		oc = lookup_option (&dhcp_universe, packet -> options,

+				    DHO_PXE_CLIENT_ID);

 	memset (&data, 0, sizeof data);

 	if (oc &&

 	    evaluate_option_cache (&data, packet, (struct lease *)0,

@@ -1286,6 +1293,9 @@ void dhcpinform (packet, ms_nulltp)

          */

 	oc = lookup_option(&dhcp_universe, packet->options,

 			   DHO_DHCP_CLIENT_IDENTIFIER);

+	if (!oc)

+		oc = lookup_option (&dhcp_universe, packet -> options,

+				    DHO_PXE_CLIENT_ID);

 	memset(&d1, 0, sizeof(d1));

 	if (oc &&

 	    evaluate_option_cache(&d1, packet, NULL, NULL,

@@ -2381,6 +2391,9 @@ void ack_lease (packet, lease, offer, wh

 		   can be used. */

 		oc = lookup_option (&dhcp_universe, packet -> options,

 				    DHO_DHCP_CLIENT_IDENTIFIER);

+		if (!oc)

+			oc = lookup_option (&dhcp_universe, packet -> options,

+					    DHO_PXE_CLIENT_ID);

 		if (oc &&

 		    evaluate_option_cache (&d1, packet, lease,

 					   (struct client_state *)0,

@@ -2962,6 +2975,9 @@ void ack_lease (packet, lease, offer, wh

 		/* Record the uid, if given... */

 		oc = lookup_option (&dhcp_universe, packet -> options,

 				    DHO_DHCP_CLIENT_IDENTIFIER);

+		if (!oc)

+			oc = lookup_option (&dhcp_universe, packet -> options,

+					    DHO_PXE_CLIENT_ID);

 		if (oc &&

 		    evaluate_option_cache(&d1, packet, lease, NULL,

 					  packet->options, state->options,

@@ -4068,6 +4084,9 @@ int find_lease (struct lease **lp,

 	   specified unique client identifier. */

 	oc = lookup_option (&dhcp_universe, packet -> options,

 			    DHO_DHCP_CLIENT_IDENTIFIER);

+	if (!oc)

+		oc = lookup_option (&dhcp_universe, packet -> options,

+				    DHO_PXE_CLIENT_ID);

 	memset (&client_identifier, 0, sizeof client_identifier);

 	if (oc &&

 	    evaluate_option_cache (&client_identifier,

diff -up dhcp-4.3.5b1/server/dhcpd.conf.5.option97 dhcp-4.3.5b1/server/dhcpd.conf.5

--- dhcp-4.3.5b1/server/dhcpd.conf.5.option97	2016-09-12 17:17:13.885690972 +0200

+++ dhcp-4.3.5b1/server/dhcpd.conf.5	2016-09-12 17:17:13.974691043 +0200

@@ -1587,10 +1587,12 @@ should be a name identifying the host.

 not specified for the host, \fIhostname\fR is used.

 .PP

 \fIHost\fR declarations are matched to actual DHCP or BOOTP clients

-by matching the \fRdhcp-client-identifier\fR option specified in the

+by matching the \fIdhcp-client-identifier\fR or \fIpxe-client-id\fR

+options specified in the

 \fIhost\fR declaration to the one supplied by the client, or, if the

 \fIhost\fR declaration or the client does not provide a

-\fRdhcp-client-identifier\fR option, by matching the \fIhardware\fR

+\fIdhcp-client-identifier\fR or \fIpxe-client-id\fR options,

+by matching the \fIhardware\fR

 parameter in the \fIhost\fR declaration to the network hardware

 address supplied by the client.  BOOTP clients do not normally

 provide a \fIdhcp-client-identifier\fR, so the hardware address must

@@ -1602,7 +1604,8 @@ to identify hosts.

 .PP

 Please be aware that

 .B only

-the \fIdhcp-client-identifier\fR option and the hardware address can be

+the \fIdhcp-client-identifier\fR and \fIpxe-client-id\fR

+options and the hardware address can be

 used to match a host declaration, or the \fIhost-identifier option\fR

 parameter for DHCPv6 servers.  For example, it is not possible to

 match a host declaration to a \fIhost-name\fR option.  This is

diff -up dhcp-4.3.5b1/server/dhcpleasequery.c.option97 dhcp-4.3.5b1/server/dhcpleasequery.c

--- dhcp-4.3.5b1/server/dhcpleasequery.c.option97	2016-08-26 20:19:53.000000000 +0200

+++ dhcp-4.3.5b1/server/dhcpleasequery.c	2016-09-12 17:17:13.974691043 +0200

@@ -273,7 +273,7 @@ dhcpleasequery(struct packet *packet, in

 		 */

 		memset(&uid, 0, sizeof(uid));

-		if (get_option(&uid, 

+		i = get_option(&uid,

 			       &dhcp_universe,

 			       packet,

 			       NULL,

@@ -283,8 +283,20 @@ dhcpleasequery(struct packet *packet, in

 			       packet->options, 

 			       &global_scope,

 			       DHO_DHCP_CLIENT_IDENTIFIER,

-			       MDL)) {

-

+			       MDL);

+		if (!i)

+			i = get_option(&uid,

+				       &dhcp_universe,

+				       packet,

+				       NULL,

+				       NULL,

+				       packet->options,

+				       NULL,

+				       packet->options,

+				       &global_scope,

+				       DHO_PXE_CLIENT_ID,

+				       MDL);

+		if (i) {

 			snprintf(dbg_info, 

 				 sizeof(dbg_info), 

 				 "client-id %s",

diff -up dhcp-4.3.5b1/server/failover.c.option97 dhcp-4.3.5b1/server/failover.c

--- dhcp-4.3.5b1/server/failover.c.option97	2016-08-26 20:19:53.000000000 +0200

+++ dhcp-4.3.5b1/server/failover.c	2016-09-12 17:17:13.975691044 +0200

@@ -5957,6 +5957,9 @@ int load_balance_mine (struct packet *pa

 	oc = lookup_option(&dhcp_universe, packet->options,

 			   DHO_DHCP_CLIENT_IDENTIFIER);

+	if (!oc)

+		oc = lookup_option(&dhcp_universe, packet -> options,

+				    DHO_PXE_CLIENT_ID);

 	memset(&ds, 0, sizeof ds);

 	if (oc &&

 	    evaluate_option_cache(&ds, packet, NULL, NULL,

diff -up dhcp-4.3.5b1/server/mdb.c.option97 dhcp-4.3.5b1/server/mdb.c

--- dhcp-4.3.5b1/server/mdb.c.option97	2016-08-26 20:19:53.000000000 +0200

+++ dhcp-4.3.5b1/server/mdb.c	2016-09-12 17:17:13.975691044 +0200

@@ -129,8 +129,9 @@ static int find_uid_statement (struct ex

 	    esp -> data.option &&

 	    (esp -> data.option -> option -> universe ==

 	     &dhcp_universe) &&

-	    (esp -> data.option -> option -> code ==

-	     DHO_DHCP_CLIENT_IDENTIFIER)) {

+	    ((esp -> data.option -> option -> code ==

+						DHO_DHCP_CLIENT_IDENTIFIER) ||

+	     (esp -> data.option -> option -> code == DHO_PXE_CLIENT_ID))) {

 		if (condp) {

 			log_error ("dhcp client identifier may not be %s",

 				   "specified conditionally.");