[eap] Define a supplicant model for EAP and EAPoL

Extend the EAP model to include a record of whether or not EAP
authentication has completed (successfully or otherwise), and to
provide a method for transmitting EAP responses.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

5 files changed, 184 insertions, 27 deletions

diff --git a/src/include/ipxe/eap.h b/src/include/ipxe/eap.h
index 6fe7018..e5f6065 100644
--- a/src/include/ipxe/eap.h
+++ b/src/include/ipxe/eap.h
@@ -64,6 +64,25 @@ union eap_packet {
  */
 #define EAP_BLOCK_TIMEOUT ( 45 * TICKS_PER_SEC )
 
-extern int eap_rx ( struct net_device *netdev, const void *data, size_t len );
+/** An EAP supplicant */
+struct eap_supplicant {
+	/** Network device */
+	struct net_device *netdev;
+	/** Authentication outcome is final */
+	int done;
+	/**
+	 * Transmit EAP response
+	 *
+	 * @v supplicant	EAP supplicant
+	 * @v data		Response data
+	 * @v len		Length of response data
+	 * @ret rc		Return status code
+	 */
+	int ( * tx ) ( struct eap_supplicant *supplicant,
+		       const void *data, size_t len );
+};
+
+extern int eap_rx ( struct eap_supplicant *supplicant,
+		    const void *data, size_t len );
 
 #endif /* _IPXE_EAP_H */
diff --git a/src/include/ipxe/eapol.h b/src/include/ipxe/eapol.h
index 952d6c7..f6009a2 100644
--- a/src/include/ipxe/eapol.h
+++ b/src/include/ipxe/eapol.h
@@ -12,6 +12,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <stdint.h>
 #include <ipxe/netdevice.h>
 #include <ipxe/tables.h>
+#include <ipxe/eap.h>
 
 /** EAPoL header */
 struct eapol_header {
@@ -32,6 +33,12 @@ struct eapol_header {
 /** EAPoL key */
 #define EAPOL_TYPE_KEY 5
 
+/** An EAPoL supplicant */
+struct eapol_supplicant {
+	/** EAP supplicant */
+	struct eap_supplicant eap;
+};
+
 /** An EAPoL handler */
 struct eapol_handler {
 	/** Type */
@@ -39,15 +46,15 @@ struct eapol_handler {
 	/**
 	 * Process received packet
 	 *
+	 * @v supplicant	EAPoL supplicant
 	 * @v iobuf		I/O buffer
-	 * @v netdev		Network device
 	 * @v ll_source		Link-layer source address
 	 * @ret rc		Return status code
 	 *
 	 * This method takes ownership of the I/O buffer.
 	 */
-	int ( * rx ) ( struct io_buffer *iobuf, struct net_device *netdev,
-		       const void *ll_source );
+	int ( * rx ) ( struct eapol_supplicant *supplicant,
+		       struct io_buffer *iobuf, const void *ll_source );
 };
 
 /** EAPoL handler table */
diff --git a/src/net/80211/wpa.c b/src/net/80211/wpa.c
index 1484d0e..17c11b8 100644
--- a/src/net/80211/wpa.c
+++ b/src/net/80211/wpa.c
@@ -761,13 +761,14 @@ static int wpa_handle_1_of_2 ( struct wpa_common_ctx *ctx,
 /**
  * Handle receipt of EAPOL-Key frame for WPA
  *
- * @v iob	I/O buffer
- * @v netdev	Network device
- * @v ll_source	Source link-layer address
+ * @v supplicant	EAPoL supplicant
+ * @v iob		I/O buffer
+ * @v ll_source		Source link-layer address
  */
-static int eapol_key_rx ( struct io_buffer *iob, struct net_device *netdev,
-			  const void *ll_source )
+static int eapol_key_rx ( struct eapol_supplicant *supplicant,
+			  struct io_buffer *iob, const void *ll_source )
 {
+	struct net_device *netdev = supplicant->eap.netdev;
 	struct net80211_device *dev = net80211_get ( netdev );
 	struct eapol_header *eapol;
 	struct eapol_key_pkt *pkt;
diff --git a/src/net/eap.c b/src/net/eap.c
index 8d1d540..beaeb61 100644
--- a/src/net/eap.c
+++ b/src/net/eap.c
@@ -36,10 +36,11 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 /**
  * Handle EAP Request-Identity
  *
- * @v netdev		Network device
+ * @v supplicant	EAP supplicant
  * @ret rc		Return status code
  */
-static int eap_rx_request_identity ( struct net_device *netdev ) {
+static int eap_rx_request_identity ( struct eap_supplicant *supplicant ) {
+	struct net_device *netdev = supplicant->netdev;
 
 	/* Treat Request-Identity as blocking the link */
 	DBGC ( netdev, "EAP %s Request-Identity blocking link\n",
@@ -52,13 +53,14 @@ static int eap_rx_request_identity ( struct net_device *netdev ) {
 /**
  * Handle EAP Request
  *
- * @v netdev		Network device
+ * @v supplicant	EAP supplicant
  * @v req		EAP request
  * @v len		Length of EAP request
  * @ret rc		Return status code
  */
-static int eap_rx_request ( struct net_device *netdev,
+static int eap_rx_request ( struct eap_supplicant *supplicant,
 			    const struct eap_request *req, size_t len ) {
+	struct net_device *netdev = supplicant->netdev;
 
 	/* Sanity check */
 	if ( len < sizeof ( *req ) ) {
@@ -67,10 +69,13 @@ static int eap_rx_request ( struct net_device *netdev,
 		return -EINVAL;
 	}
 
+	/* Mark authentication as incomplete */
+	supplicant->done = 0;
+
 	/* Handle according to type */
 	switch ( req->type ) {
 	case EAP_TYPE_IDENTITY:
-		return eap_rx_request_identity ( netdev );
+		return eap_rx_request_identity ( supplicant );
 	default:
 		DBGC ( netdev, "EAP %s requested type %d unknown:\n",
 		       netdev->name, req->type );
@@ -82,10 +87,14 @@ static int eap_rx_request ( struct net_device *netdev,
 /**
  * Handle EAP Success
  *
- * @v netdev		Network device
+ * @v supplicant	EAP supplicant
  * @ret rc		Return status code
  */
-static int eap_rx_success ( struct net_device *netdev ) {
+static int eap_rx_success ( struct eap_supplicant *supplicant ) {
+	struct net_device *netdev = supplicant->netdev;
+
+	/* Mark authentication as complete */
+	supplicant->done = 1;
 
 	/* Mark link as unblocked */
 	DBGC ( netdev, "EAP %s Success\n", netdev->name );
@@ -97,10 +106,14 @@ static int eap_rx_success ( struct net_device *netdev ) {
 /**
  * Handle EAP Failure
  *
- * @v netdev		Network device
+ * @v supplicant	EAP supplicant
  * @ret rc		Return status code
  */
-static int eap_rx_failure ( struct net_device *netdev ) {
+static int eap_rx_failure ( struct eap_supplicant *supplicant ) {
+	struct net_device *netdev = supplicant->netdev;
+
+	/* Mark authentication as complete */
+	supplicant->done = 1;
 
 	/* Record error */
 	DBGC ( netdev, "EAP %s Failure\n", netdev->name );
@@ -110,12 +123,14 @@ static int eap_rx_failure ( struct net_device *netdev ) {
 /**
  * Handle EAP packet
  *
- * @v netdev		Network device
+ * @v supplicant	EAP supplicant
  * @v data		EAP packet
  * @v len		Length of EAP packet
  * @ret rc		Return status code
  */
-int eap_rx ( struct net_device *netdev, const void *data, size_t len ) {
+int eap_rx ( struct eap_supplicant *supplicant, const void *data,
+	     size_t len ) {
+	struct net_device *netdev = supplicant->netdev;
 	const union eap_packet *eap = data;
 
 	/* Sanity check */
@@ -128,11 +143,11 @@ int eap_rx ( struct net_device *netdev, const void *data, size_t len ) {
 	/* Handle according to code */
 	switch ( eap->hdr.code ) {
 	case EAP_CODE_REQUEST:
-		return eap_rx_request ( netdev, &eap->req, len );
+		return eap_rx_request ( supplicant, &eap->req, len );
 	case EAP_CODE_SUCCESS:
-		return eap_rx_success ( netdev );
+		return eap_rx_success ( supplicant );
 	case EAP_CODE_FAILURE:
-		return eap_rx_failure ( netdev );
+		return eap_rx_failure ( supplicant );
 	default:
 		DBGC ( netdev, "EAP %s unsupported code %d\n",
 		       netdev->name, eap->hdr.code );
diff --git a/src/net/eapol.c b/src/net/eapol.c
index 3578f0e..172037c 100644
--- a/src/net/eapol.c
+++ b/src/net/eapol.c
@@ -28,7 +28,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <byteswap.h>
 #include <ipxe/iobuf.h>
 #include <ipxe/if_ether.h>
+#include <ipxe/if_arp.h>
 #include <ipxe/netdevice.h>
+#include <ipxe/vlan.h>
 #include <ipxe/eap.h>
 #include <ipxe/eapol.h>
 
@@ -38,6 +40,13 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  *
  */
 
+struct net_driver eapol_driver __net_driver;
+
+/** EAPoL destination MAC address */
+static const uint8_t eapol_mac[ETH_ALEN] = {
+	0x01, 0x80, 0xc2, 0x00, 0x00, 0x03
+};
+
 /**
  * Process EAPoL packet
  *
@@ -51,12 +60,25 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 static int eapol_rx ( struct io_buffer *iobuf, struct net_device *netdev,
 		      const void *ll_dest __unused, const void *ll_source,
 		      unsigned int flags __unused ) {
+	struct eapol_supplicant *supplicant;
 	struct eapol_header *eapol;
 	struct eapol_handler *handler;
 	size_t remaining;
 	size_t len;
 	int rc;
 
+	/* Find matching supplicant */
+	supplicant = netdev_priv ( netdev, &eapol_driver );
+
+	/* Ignore non-EAPoL devices */
+	if ( ! supplicant->eap.netdev ) {
+		DBGC ( netdev, "EAPOL %s is not an EAPoL device\n",
+		       netdev->name );
+		DBGC_HDA ( netdev, 0, iobuf->data, iob_len ( iobuf ) );
+		rc = -ENOTTY;
+		goto drop;
+	}
+
 	/* Sanity checks */
 	if ( iob_len ( iobuf ) < sizeof ( *eapol ) ) {
 		DBGC ( netdev, "EAPOL %s underlength header:\n",
@@ -83,7 +105,7 @@ static int eapol_rx ( struct io_buffer *iobuf, struct net_device *netdev,
 	/* Handle according to type */
 	for_each_table_entry ( handler, EAPOL_HANDLERS ) {
 		if ( handler->type == eapol->type ) {
-			return handler->rx ( iob_disown ( iobuf ) , netdev,
+			return handler->rx ( supplicant, iob_disown ( iobuf ),
 					     ll_source );
 		}
 	}
@@ -107,12 +129,14 @@ struct net_protocol eapol_protocol __net_protocol = {
 /**
  * Process EAPoL-encapsulated EAP packet
  *
- * @v netdev		Network device
+ * @v supplicant	EAPoL supplicant
  * @v ll_source		Link-layer source address
  * @ret rc		Return status code
  */
-static int eapol_eap_rx ( struct io_buffer *iobuf, struct net_device *netdev,
+static int eapol_eap_rx ( struct eapol_supplicant *supplicant,
+			  struct io_buffer *iobuf,
 			  const void *ll_source __unused ) {
+	struct net_device *netdev = supplicant->eap.netdev;
 	struct eapol_header *eapol;
 	int rc;
 
@@ -123,7 +147,8 @@ static int eapol_eap_rx ( struct io_buffer *iobuf, struct net_device *netdev,
 	eapol = iob_pull ( iobuf, sizeof ( *eapol ) );
 
 	/* Process EAP packet */
-	if ( ( rc = eap_rx ( netdev, iobuf->data, iob_len ( iobuf ) ) ) != 0 ) {
+	if ( ( rc = eap_rx ( &supplicant->eap, iobuf->data,
+			     iob_len ( iobuf ) ) ) != 0 ) {
 		DBGC ( netdev, "EAPOL %s v%d EAP failed: %s\n",
 		       netdev->name, eapol->version, strerror ( rc ) );
 		goto drop;
@@ -139,3 +164,93 @@ struct eapol_handler eapol_eap __eapol_handler = {
 	.type = EAPOL_TYPE_EAP,
 	.rx = eapol_eap_rx,
 };
+
+/**
+ * Transmit EAPoL packet
+ *
+ * @v supplicant	EAPoL supplicant
+ * @v type		Packet type
+ * @v data		Packet body
+ * @v len		Length of packet body
+ * @ret rc		Return status code
+ */
+static int eapol_tx ( struct eapol_supplicant *supplicant, unsigned int type,
+		      const void *data, size_t len ) {
+	struct net_device *netdev = supplicant->eap.netdev;
+	struct io_buffer *iobuf;
+	struct eapol_header *eapol;
+	int rc;
+
+	/* Allocate I/O buffer */
+	iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *eapol ) + len );
+	if ( ! iobuf )
+		return -ENOMEM;
+	iob_reserve ( iobuf, MAX_LL_HEADER_LEN );
+
+	/* Construct EAPoL header */
+	eapol = iob_put ( iobuf, sizeof ( *eapol ) );
+	eapol->version = EAPOL_VERSION_2001;
+	eapol->type = type;
+	eapol->len = htons ( len );
+
+	/* Append packet body */
+	memcpy ( iob_put ( iobuf, len ), data, len );
+
+	/* Transmit packet */
+	if ( ( rc = net_tx ( iob_disown ( iobuf ), netdev, &eapol_protocol,
+			     &eapol_mac, netdev->ll_addr ) ) != 0 ) {
+		DBGC ( netdev, "EAPOL %s could not transmit type %d: %s\n",
+		       netdev->name, type, strerror ( rc ) );
+		DBGC_HDA ( netdev, 0, data, len );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Transmit EAPoL-encapsulated EAP packet
+ *
+ * @v supplicant	EAPoL supplicant
+ * @v ll_source		Link-layer source address
+ * @ret rc		Return status code
+ */
+static int eapol_eap_tx ( struct eap_supplicant *eap, const void *data,
+			  size_t len ) {
+	struct eapol_supplicant *supplicant =
+		container_of ( eap, struct eapol_supplicant, eap );
+
+	/* Transmit encapsulated packet */
+	return eapol_tx ( supplicant, EAPOL_TYPE_EAP, data, len );
+}
+
+/**
+ * Create EAPoL supplicant
+ *
+ * @v netdev		Network device
+ * @v priv		Private data
+ * @ret rc		Return status code
+ */
+static int eapol_probe ( struct net_device *netdev, void *priv ) {
+	struct eapol_supplicant *supplicant = priv;
+	struct ll_protocol *ll_protocol = netdev->ll_protocol;
+
+	/* Ignore non-EAPoL devices */
+	if ( ll_protocol->ll_proto != htons ( ARPHRD_ETHER ) )
+		return 0;
+	if ( vlan_tag ( netdev ) )
+		return 0;
+
+	/* Initialise structure */
+	supplicant->eap.netdev = netdev;
+	supplicant->eap.tx = eapol_eap_tx;
+
+	return 0;
+}
+
+/** EAPoL driver */
+struct net_driver eapol_driver __net_driver = {
+	.name = "EAPoL",
+	.priv_len = sizeof ( struct eapol_supplicant ),
+	.probe = eapol_probe,
+};