2 files changed, 81 insertions, 0 deletions

diff --git a/src/include/ipxe/eapol.h b/src/include/ipxe/eapol.h
index f6009a2ff..d4ea39208 100644
--- a/src/include/ipxe/eapol.h
+++ b/src/include/ipxe/eapol.h
@@ -30,6 +30,9 @@ struct eapol_header {
 /** EAPoL-encapsulated EAP packets */
 #define EAPOL_TYPE_EAP 0
 
+/** EAPoL start */
+#define EAPOL_TYPE_START 1
+
 /** EAPoL key */
 #define EAPOL_TYPE_KEY 5
 
@@ -37,8 +40,13 @@ struct eapol_header {
 struct eapol_supplicant {
 	/** EAP supplicant */
 	struct eap_supplicant eap;
+	/** EAPoL-Start retransmission timer */
+	struct retry_timer timer;
 };
 
+/** Delay between EAPoL-Start packets */
+#define EAPOL_START_INTERVAL ( 2 * TICKS_PER_SEC )
+
 /** An EAPoL handler */
 struct eapol_handler {
 	/** Type */
diff --git a/src/net/eapol.c b/src/net/eapol.c
index 172037ce1..1b843e896 100644
--- a/src/net/eapol.c
+++ b/src/net/eapol.c
@@ -31,6 +31,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/if_arp.h>
 #include <ipxe/netdevice.h>
 #include <ipxe/vlan.h>
+#include <ipxe/retry.h>
 #include <ipxe/eap.h>
 #include <ipxe/eapol.h>
 
@@ -48,6 +49,37 @@ static const uint8_t eapol_mac[ETH_ALEN] = {
 };
 
 /**
+ * Update EAPoL supplicant state
+ *
+ * @v supplicant	EAPoL supplicant
+ * @v timeout		Timer ticks until next EAPoL-Start (if applicable)
+ */
+static void eapol_update ( struct eapol_supplicant *supplicant,
+			   unsigned long timeout ) {
+	struct net_device *netdev = supplicant->eap.netdev;
+
+	/* Check device and EAP state */
+	if ( netdev_is_open ( netdev ) && netdev_link_ok ( netdev ) ) {
+		if ( supplicant->eap.done ) {
+
+			/* EAP has completed: stop sending EAPoL-Start */
+			stop_timer ( &supplicant->timer );
+
+		} else if ( ! timer_running ( &supplicant->timer ) ) {
+
+			/* EAP has not yet begun: start sending EAPoL-Start */
+			start_timer_fixed ( &supplicant->timer, timeout );
+		}
+
+	} else {
+
+		/* Not ready: clear completion and stop sending EAPoL-Start */
+		supplicant->eap.done = 0;
+		stop_timer ( &supplicant->timer );
+	}
+}
+
+/**
  * Process EAPoL packet
  *
  * @v iobuf		I/O buffer
@@ -154,6 +186,9 @@ static int eapol_eap_rx ( struct eapol_supplicant *supplicant,
 		goto drop;
 	}
 
+	/* Update supplicant state */
+	eapol_update ( supplicant, EAPOL_START_INTERVAL );
+
  drop:
 	free_iob ( iobuf );
 	return rc;
@@ -225,6 +260,25 @@ static int eapol_eap_tx ( struct eap_supplicant *eap, const void *data,
 }
 
 /**
+ * (Re)transmit EAPoL-Start packet
+ *
+ * @v timer		EAPoL-Start timer
+ * @v expired		Failure indicator
+ */
+static void eapol_expired ( struct retry_timer *timer, int fail __unused ) {
+	struct eapol_supplicant *supplicant =
+		container_of ( timer, struct eapol_supplicant, timer );
+	struct net_device *netdev = supplicant->eap.netdev;
+
+	/* Schedule next transmission */
+	start_timer_fixed ( timer, EAPOL_START_INTERVAL );
+
+	/* Transmit EAPoL-Start, ignoring errors */
+	DBGC2 ( netdev, "EAPOL %s transmitting Start\n", netdev->name );
+	eapol_tx ( supplicant, EAPOL_TYPE_START, NULL, 0 );
+}
+
+/**
  * Create EAPoL supplicant
  *
  * @v netdev		Network device
@@ -244,13 +298,32 @@ static int eapol_probe ( struct net_device *netdev, void *priv ) {
 	/* Initialise structure */
 	supplicant->eap.netdev = netdev;
 	supplicant->eap.tx = eapol_eap_tx;
+	timer_init ( &supplicant->timer, eapol_expired, &netdev->refcnt );
 
 	return 0;
 }
 
+/**
+ * Handle EAPoL supplicant state change
+ *
+ * @v netdev		Network device
+ * @v priv		Private data
+ */
+static void eapol_notify ( struct net_device *netdev __unused, void *priv ) {
+	struct eapol_supplicant *supplicant = priv;
+
+	/* Ignore non-EAPoL devices */
+	if ( ! supplicant->eap.netdev )
+		return;
+
+	/* Update supplicant state */
+	eapol_update ( supplicant, 0 );
+}
+
 /** EAPoL driver */
 struct net_driver eapol_driver __net_driver = {
 	.name = "EAPoL",
 	.priv_len = sizeof ( struct eapol_supplicant ),
 	.probe = eapol_probe,
+	.notify = eapol_notify,
 };