diff options
Diffstat (limited to 'qemu/roms/ipxe/src/net/stp.c')
| -rw-r--r-- | qemu/roms/ipxe/src/net/stp.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/net/stp.c b/qemu/roms/ipxe/src/net/stp.c new file mode 100644 index 000000000..d4e65a1a2 --- /dev/null +++ b/qemu/roms/ipxe/src/net/stp.c @@ -0,0 +1,152 @@ +/* + * 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, 0x01, \ + "Non-STP packet received" ) +#define ENOTSUP_VERSION __einfo_error ( EINFO_ENOTSUP_VERSION ) +#define EINFO_ENOTSUP_VERSION \ + __einfo_uniqify ( EINFO_ENOTSUP, 0x01, \ + "Legacy STP packet received" ) +#define ENOTSUP_TYPE __einfo_error ( EINFO_ENOTSUP_TYPE ) +#define EINFO_ENOTSUP_TYPE \ + __einfo_uniqify ( EINFO_ENOTSUP, 0x01, \ + "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, +}; |