[eapol] Replace EAPoL code

Replace the GPL2+-only EAPoL code (currently used only for WPA) with
new code licensed under GPL2+-or-UBDL.

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

3 files changed, 109 insertions, 146 deletions

diff --git a/src/include/ipxe/eapol.h b/src/include/ipxe/eapol.h
index 5ca9c28..612dd36 100644
--- a/src/include/ipxe/eapol.h
+++ b/src/include/ipxe/eapol.h
@@ -1,114 +1,58 @@
-/*
- * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
 #ifndef _IPXE_EAPOL_H
 #define _IPXE_EAPOL_H
 
 /** @file
  *
- * Definitions for EAPOL (Extensible Authentication Protocol over
- * LANs) frames. Definitions for the packets usually encapsulated in
- * them are elsewhere.
- */
-
-#include <ipxe/tables.h>
-#include <stdint.h>
-
-FILE_LICENCE ( GPL2_OR_LATER );
-
-
-/**
- * @defgroup eapol_type EAPOL archetype identifiers
- * @{
- */
-#define EAPOL_TYPE_EAP		0 /**< EAP authentication handshake packet */
-#define EAPOL_TYPE_START	1 /**< Request by Peer to begin (no data) */
-#define EAPOL_TYPE_LOGOFF	2 /**< Request by Peer to terminate (no data) */
-#define EAPOL_TYPE_KEY		3 /**< EAPOL-Key packet */
-/** @} */
-
-/** Expected EAPOL version field value
- *
- * Version 2 is often seen and has no format differences from version 1;
- * however, many older APs will completely drop version-2 packets, so
- * we advertise ourselves as version 1.
- */
-#define EAPOL_THIS_VERSION	1
-
-/** Length of an EAPOL frame header */
-#define EAPOL_HDR_LEN		4
-
-/** An EAPOL frame
+ * Extensible Authentication Protocol over LAN (EAPoL)
  *
- * This may encapsulate an eap_pkt, an eapol_key_pkt, or a Start or
- * Logoff request with no data attached. It is transmitted directly in
- * an Ethernet frame, with no IP packet header.
  */
-struct eapol_frame
-{
-	/** EAPOL version identifier, always 1 */
-	u8 version;
 
-	/** EAPOL archetype identifier indicating format of payload */
-	u8 type;
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
-	/** Length of payload, in network byte order */
-	u16 length;
+#include <stdint.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/tables.h>
 
-	/** Payload, if @a type is EAP or EAPOL-Key */
-	u8 data[0];
+/** EAPoL header */
+struct eapol_header {
+	/** Version */
+	uint8_t version;
+	/** Type */
+	uint8_t type;
+	/** Payload length */
+	uint16_t len;
 } __attribute__ (( packed ));
 
+/** 802.1X-2001 */
+#define EAPOL_VERSION_2001 1
 
-/** An EAPOL frame type handler
- *
- * Normally there will be at most two of these, one for EAP and one
- * for EAPOL-Key frames. The EAPOL interface code handles Start and
- * Logoff directly.
- */
-struct eapol_handler
-{
-	/** EAPOL archetype identifier for payload this handler will handle */
-	u8 type;
+/** EAPoL key */
+#define EAPOL_TYPE_KEY 5
 
-	/** Receive EAPOL-encapsulated packet of specified type
-	 *
-	 * @v iob	I/O buffer containing packet payload
-	 * @v netdev	Network device from which packet was received
-	 * @V ll_dest	Destination link-layer address
-	 * @v ll_source	Source link-layer address
-	 * @ret rc	Return status code
+/** An EAPoL handler */
+struct eapol_handler {
+	/** Type */
+	uint8_t type;
+	/**
+	 * Process received packet
 	 *
-	 * The I/O buffer will have the EAPOL header pulled off it, so
-	 * @c iob->data points to the first byte of the payload.
+	 * @v iobuf		I/O buffer
+	 * @v netdev		Network device
+	 * @v ll_source		Link-layer source address
+	 * @ret rc		Return status code
 	 *
-	 * This function takes ownership of the I/O buffer passed to it.
+	 * This method takes ownership of the I/O buffer.
 	 */
-	int ( * rx ) ( struct io_buffer *iob, struct net_device *netdev,
-		       const void *ll_dest, const void *ll_source );
+	int ( * rx ) ( struct io_buffer *iobuf, struct net_device *netdev,
+		       const void *ll_source );
 };
 
-#define EAPOL_HANDLERS	__table ( struct eapol_handler, "eapol_handlers" )
-#define __eapol_handler	__table_entry ( EAPOL_HANDLERS, 01 )
+/** EAPoL handler table */
+#define EAPOL_HANDLERS __table ( struct eapol_handler, "eapol_handlers" )
 
+/** Declare an EAPoL handler */
+#define __eapol_handler __table_entry ( EAPOL_HANDLERS, 01 )
 
 extern struct net_protocol eapol_protocol __net_protocol;
 
-
 #endif /* _IPXE_EAPOL_H */
diff --git a/src/net/80211/wpa.c b/src/net/80211/wpa.c
index 5ec5005..1484d0e 100644
--- a/src/net/80211/wpa.c
+++ b/src/net/80211/wpa.c
@@ -414,12 +414,13 @@ static int wpa_maybe_install_gtk ( struct wpa_common_ctx *ctx,
 static struct io_buffer * wpa_alloc_frame ( int kdlen )
 {
 	struct io_buffer *ret = alloc_iob ( sizeof ( struct eapol_key_pkt ) +
-					    kdlen + EAPOL_HDR_LEN +
+					    kdlen +
+					    sizeof ( struct eapol_header ) +
 					    MAX_LL_HEADER_LEN );
 	if ( ! ret )
 		return NULL;
 
-	iob_reserve ( ret, MAX_LL_HEADER_LEN + EAPOL_HDR_LEN );
+	iob_reserve ( ret, MAX_LL_HEADER_LEN + sizeof ( struct eapol_header ) );
 	memset ( iob_put ( ret, sizeof ( struct eapol_key_pkt ) ), 0,
 		 sizeof ( struct eapol_key_pkt ) );
 
@@ -442,19 +443,19 @@ static int wpa_send_eapol ( struct io_buffer *iob, struct wpa_common_ctx *ctx,
 			    struct wpa_kie *kie )
 {
 	struct eapol_key_pkt *pkt = iob->data;
-	struct eapol_frame *eapol = iob_push ( iob, EAPOL_HDR_LEN );
+	struct eapol_header *eapol = iob_push ( iob, sizeof ( *eapol ) );
 
 	pkt->info = htons ( pkt->info );
 	pkt->keysize = htons ( pkt->keysize );
 	pkt->datalen = htons ( pkt->datalen );
 	pkt->replay = cpu_to_be64 ( pkt->replay );
-	eapol->version = EAPOL_THIS_VERSION;
+	eapol->version = EAPOL_VERSION_2001;
 	eapol->type = EAPOL_TYPE_KEY;
-	eapol->length = htons ( iob->tail - iob->data - sizeof ( *eapol ) );
+	eapol->len = htons ( iob->tail - iob->data - sizeof ( *eapol ) );
 
 	memset ( pkt->mic, 0, sizeof ( pkt->mic ) );
 	if ( kie )
-		kie->mic ( &ctx->ptk.kck, eapol, EAPOL_HDR_LEN +
+		kie->mic ( &ctx->ptk.kck, eapol, sizeof ( *eapol ) +
 			   sizeof ( *pkt ) + ntohs ( pkt->datalen ),
 			   pkt->mic );
 
@@ -762,21 +763,23 @@ static int wpa_handle_1_of_2 ( struct wpa_common_ctx *ctx,
  *
  * @v iob	I/O buffer
  * @v netdev	Network device
- * @v ll_dest	Link-layer destination address
  * @v ll_source	Source link-layer address
  */
 static int eapol_key_rx ( struct io_buffer *iob, struct net_device *netdev,
-			  const void *ll_dest __unused,
 			  const void *ll_source )
 {
 	struct net80211_device *dev = net80211_get ( netdev );
-	struct eapol_key_pkt *pkt = iob->data;
+	struct eapol_header *eapol;
+	struct eapol_key_pkt *pkt;
 	int is_rsn, found_ctx;
 	struct wpa_common_ctx *ctx;
 	int rc = 0;
 	struct wpa_kie *kie;
 	u8 their_mic[16], our_mic[16];
 
+	eapol = iob->data;
+	pkt = ( ( ( void * ) eapol ) + sizeof ( *eapol ) );
+
 	if ( pkt->type != EAPOL_KEY_TYPE_WPA &&
 	     pkt->type != EAPOL_KEY_TYPE_RSN ) {
 		DBG ( "EAPOL-Key: packet not of 802.11 type\n" );
@@ -840,8 +843,8 @@ static int eapol_key_rx ( struct io_buffer *iob, struct net_device *netdev,
 	if ( ntohs ( pkt->info ) & EAPOL_KEY_INFO_KEY_MIC ) {
 		memcpy ( their_mic, pkt->mic, sizeof ( pkt->mic ) );
 		memset ( pkt->mic, 0, sizeof ( pkt->mic ) );
-		kie->mic ( &ctx->ptk.kck, ( void * ) pkt - EAPOL_HDR_LEN,
-			   EAPOL_HDR_LEN + sizeof ( *pkt ) +
+		kie->mic ( &ctx->ptk.kck, eapol,
+			   sizeof ( *eapol ) + sizeof ( *pkt ) +
 			   ntohs ( pkt->datalen ), our_mic );
 		DBGC2 ( ctx, "WPA %p MIC comparison (theirs, ours):\n", ctx );
 		DBGC2_HD ( ctx, their_mic, 16 );
diff --git a/src/net/eapol.c b/src/net/eapol.c
index eb03629..91119d3 100644
--- a/src/net/eapol.c
+++ b/src/net/eapol.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 Joshua Oreman <oremanj@rwcr.net>.
+ * Copyright (C) 2021 Michael Brown <mbrown@fensystems.co.uk>.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -15,74 +15,90 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
  */
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <assert.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/if_ether.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/eapol.h>
 
 /** @file
  *
- * 802.1X Extensible Authentication Protocol over LANs demultiplexer
+ * Extensible Authentication Protocol over LAN (EAPoL)
  *
  */
 
-#include <ipxe/netdevice.h>
-#include <ipxe/iobuf.h>
-#include <ipxe/if_ether.h>
-#include <ipxe/eapol.h>
-#include <errno.h>
-#include <byteswap.h>
-
 /**
- * Receive EAPOL network-layer packet
+ * Process EAPoL packet
  *
- * @v iob	I/O buffer
- * @v netdev	Network device
- * @v ll_dest	Link-layer destination address
- * @v ll_source	Link-layer source address
- * @v flags	Packet flags
- *
- * This function takes ownership of the I/O buffer passed to it.
+ * @v iobuf		I/O buffer
+ * @v netdev		Network device
+ * @v ll_dest		Link-layer destination address
+ * @v ll_source		Link-layer source address
+ * @v flags		Packet flags
+ * @ret rc		Return status code
  */
-static int eapol_rx ( struct io_buffer *iob, struct net_device *netdev,
-		      const void *ll_dest, const void *ll_source,
+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_frame *eapol = iob->data;
+	struct eapol_header *eapol;
 	struct eapol_handler *handler;
+	size_t remaining;
+	size_t len;
+	int rc;
 
-	if ( iob_len ( iob ) < EAPOL_HDR_LEN ) {
-		free_iob ( iob );
-		return -EINVAL;
+	/* Sanity checks */
+	if ( iob_len ( iobuf ) < sizeof ( *eapol ) ) {
+		DBGC ( netdev, "EAPOL %s underlength header:\n",
+		       netdev->name );
+		DBGC_HDA ( netdev, 0, iobuf->data, iob_len ( iobuf ) );
+		rc = -EINVAL;
+		goto drop;
+	}
+	eapol = iobuf->data;
+	remaining = ( iob_len ( iobuf ) - sizeof ( *eapol ) );
+	len = ntohs ( eapol->len );
+	if ( len > remaining ) {
+		DBGC ( netdev, "EAPOL %s v%d type %d len %zd underlength "
+		       "payload:\n", netdev->name, eapol->version,
+		       eapol->type, len );
+		DBGC_HDA ( netdev, 0, iobuf->data, iob_len ( iobuf ) );
+		rc = -EINVAL;
+		goto drop;
 	}
 
+	/* Strip any trailing padding */
+	iob_unput ( iobuf, ( len - remaining ) );
+
+	/* Handle according to type */
 	for_each_table_entry ( handler, EAPOL_HANDLERS ) {
 		if ( handler->type == eapol->type ) {
-			iob_pull ( iob, EAPOL_HDR_LEN );
-			return handler->rx ( iob, netdev, ll_dest, ll_source );
+			return handler->rx ( iob_disown ( iobuf ) , netdev,
+					     ll_source );
 		}
 	}
+	rc = -ENOTSUP;
+	DBGC ( netdev, "EAPOL %s v%d type %d unsupported\n",
+	       netdev->name, eapol->version, eapol->type );
+	DBGC_HDA ( netdev, 0, iobuf->data, iob_len ( iobuf ) );
 
-	free_iob ( iob );
-	return -( ENOTSUP | ( ( eapol->type & 0x1f ) << 8 ) );
+ drop:
+	free_iob ( iobuf );
+	return rc;
 }
 
-/**
- * Transcribe EAPOL network-layer address
- *
- * @v net_addr	Network-layer address
- * @ret str	String representation of network-layer address
- *
- * EAPOL doesn't have network-layer addresses, so we just return the
- * string @c "<EAPOL>".
- */
-static const char * eapol_ntoa ( const void *net_addr __unused )
-{
-	return "<EAPOL>";
-}
-
-/** EAPOL network protocol */
+/** EAPoL protocol */
 struct net_protocol eapol_protocol __net_protocol = {
 	.name = "EAPOL",
-	.rx = eapol_rx,
-	.ntoa = eapol_ntoa,
 	.net_proto = htons ( ETH_P_EAPOL ),
+	.rx = eapol_rx,
 };