/*
* 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
* 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.
*
* 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_OR_UBDL );
#include <assert.h>
#include <errno.h>
#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/retry.h>
#include <ipxe/eap.h>
#include <ipxe/eapol.h>
/** @file
*
* Extensible Authentication Protocol over LAN (EAPoL)
*
*/
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
*
* @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 *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",
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 ) {
return handler->rx ( supplicant, iob_disown ( iobuf ),
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 ) );
drop:
free_iob ( iobuf );
return rc;
}
/** EAPoL protocol */
struct net_protocol eapol_protocol __net_protocol = {
.name = "EAPOL",
.net_proto = htons ( ETH_P_EAPOL ),
.rx = eapol_rx,
};
/**
* Process EAPoL-encapsulated EAP packet
*
* @v supplicant EAPoL supplicant
* @v ll_source Link-layer source address
* @ret rc Return status code
*/
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;
/* Sanity check */
assert ( iob_len ( iobuf ) >= sizeof ( *eapol ) );
/* Strip EAPoL header */
eapol = iob_pull ( iobuf, sizeof ( *eapol ) );
/* Process EAP packet */
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;
}
/* Update EAPoL-Start transmission timer */
if ( supplicant->eap.flags & EAP_FL_PASSIVE ) {
/* Stop sending EAPoL-Start */
if ( timer_running ( &supplicant->timer ) ) {
DBGC ( netdev, "EAPOL %s becoming passive\n",
netdev->name );
}
stop_timer ( &supplicant->timer );
} else if ( supplicant->eap.flags & EAP_FL_ONGOING ) {
/* Delay EAPoL-Start until after next expected packet */
DBGC ( netdev, "EAPOL %s deferring Start\n", netdev->name );
start_timer_fixed ( &supplicant->timer, EAP_WAIT_TIMEOUT );
supplicant->count = 0;
}
drop:
free_iob ( iobuf );
return rc;
}
/** EAPoL handler for EAP packets */
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 );
}
/**
* (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;
/* Stop transmitting after maximum number of attempts */
if ( supplicant->count++ >= EAPOL_START_COUNT ) {
DBGC ( netdev, "EAPOL %s giving up\n", netdev->name );
return;
}
/* 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
* @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;
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, void *priv ) {
struct eapol_supplicant *supplicant = priv;
/* Ignore non-EAPoL devices */
if ( ! supplicant->eap.netdev )
return;
/* Terminate and reset EAP when link goes down */
if ( ! ( netdev_is_open ( netdev ) && netdev_link_ok ( netdev ) ) ) {
if ( timer_running ( &supplicant->timer ) ) {
DBGC ( netdev, "EAPOL %s shutting down\n",
netdev->name );
}
supplicant->eap.flags = 0;
stop_timer ( &supplicant->timer );
return;
}
/* Do nothing if EAP is already in progress */
if ( timer_running ( &supplicant->timer ) )
return;
/* Do nothing if EAP has already finished transmitting */
if ( supplicant->eap.flags & EAP_FL_PASSIVE )
return;
/* Otherwise, start sending EAPoL-Start */
start_timer_nodelay ( &supplicant->timer );
supplicant->count = 0;
DBGC ( netdev, "EAPOL %s starting up\n", netdev->name );
}
/** EAPoL driver */
struct net_driver eapol_driver __net_driver = {
.name = "EAPoL",
.priv_len = sizeof ( struct eapol_supplicant ),
.probe = eapol_probe,
.notify = eapol_notify,
};
