/*
* Copyright (C) 2015 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 (at your option) 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 <errno.h>
#include <byteswap.h>
#include <ipxe/netdevice.h>
#include <ipxe/ethernet.h>
#include <ipxe/iobuf.h>
#include <ipxe/timer.h>
#include <ipxe/stp.h>
/** @file
*
* Spanning Tree Protocol (STP)
*
*/
/* Disambiguate the various error causes */
#define ENOTSUP_PROTOCOL __einfo_error ( EINFO_ENOTSUP_PROTOCOL )
#define EINFO_ENOTSUP_PROTOCOL \
__einfo_uniqify ( EINFO_ENOTSUP, 0x02, \
"Non-STP packet received" )
#define ENOTSUP_VERSION __einfo_error ( EINFO_ENOTSUP_VERSION )
#define EINFO_ENOTSUP_VERSION \
__einfo_uniqify ( EINFO_ENOTSUP, 0x03, \
"Legacy STP packet received" )
#define ENOTSUP_TYPE __einfo_error ( EINFO_ENOTSUP_TYPE )
#define EINFO_ENOTSUP_TYPE \
__einfo_uniqify ( EINFO_ENOTSUP, 0x04, \
"Non-RSTP packet received" )
/**
* Process incoming STP packets
*
* @v iobuf I/O buffer
* @v netdev Network device
* @v ll_source Link-layer source address
* @v flags Packet flags
* @ret rc Return status code
*/
static int stp_rx ( struct io_buffer *iobuf, struct net_device *netdev,
const void *ll_dest __unused,
const void *ll_source __unused,
unsigned int flags __unused ) {
struct stp_bpdu *stp;
unsigned int hello;
int rc;
/* Sanity check */
if ( iob_len ( iobuf ) < sizeof ( *stp ) ) {
DBGC ( netdev, "STP %s received underlength packet (%zd "
"bytes):\n", netdev->name, iob_len ( iobuf ) );
DBGC_HDA ( netdev, 0, iobuf->data, iob_len ( iobuf ) );
rc = -EINVAL;
goto done;
}
stp = iobuf->data;
/* Ignore non-RSTP packets */
if ( stp->protocol != htons ( STP_PROTOCOL ) ) {
DBGC ( netdev, "STP %s ignoring non-STP packet (protocol "
"%#04x)\n", netdev->name, ntohs ( stp->protocol ) );
rc = -ENOTSUP_PROTOCOL;
goto done;
}
if ( stp->version < STP_VERSION_RSTP ) {
DBGC ( netdev, "STP %s received legacy STP packet (version "
"%#02x)\n", netdev->name, stp->version );
rc = -ENOTSUP_VERSION;
goto done;
}
if ( stp->type != STP_TYPE_RSTP ) {
DBGC ( netdev, "STP %s received non-RSTP packet (type %#02x)\n",
netdev->name, stp->type );
rc = -ENOTSUP_TYPE;
goto done;
}
/* Dump information */
DBGC2 ( netdev, "STP %s %s port %#04x flags %#02x hello %d delay %d\n",
netdev->name, eth_ntoa ( stp->sender.mac ), ntohs ( stp->port ),
stp->flags, ntohs ( stp->hello ), ntohs ( stp->delay ) );
/* Check if port is forwarding */
if ( ! ( stp->flags & STP_FL_FORWARDING ) ) {
/* Port is not forwarding: block link for two hello times */
DBGC ( netdev, "STP %s %s port %#04x flags %#02x is not "
"forwarding\n",
netdev->name, eth_ntoa ( stp->sender.mac ),
ntohs ( stp->port ), stp->flags );
hello = ( ntohs ( stp->hello ) * ( TICKS_PER_SEC / 256 ) );
netdev_link_block ( netdev, ( hello * 2 ) );
rc = -ENETUNREACH;
goto done;
}
/* Success */
if ( netdev_link_blocked ( netdev ) ) {
DBGC ( netdev, "STP %s %s port %#04x flags %#02x is "
"forwarding\n",
netdev->name, eth_ntoa ( stp->sender.mac ),
ntohs ( stp->port ), stp->flags );
}
netdev_link_unblock ( netdev );
rc = 0;
done:
free_iob ( iobuf );
return rc;
}
/**
* Transcribe STP address
*
* @v net_addr STP address
* @ret string "<STP>"
*
* This operation is meaningless for the STP protocol.
*/
static const char * stp_ntoa ( const void *net_addr __unused ) {
return "<STP>";
}
/** STP network protocol */
struct net_protocol stp_protocol __net_protocol = {
.name = "STP",
.net_proto = htons ( ETH_P_STP ),
.rx = stp_rx,
.ntoa = stp_ntoa,
};
