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author | Michael Brown <mcb30@ipxe.org> | 2010-11-19 00:23:26 +0000 |
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committer | Michael Brown <mcb30@ipxe.org> | 2010-11-20 16:52:04 +0000 |
commit | 6fd09b541fbc426057661c7e0da4f39000b6803e (patch) | |
tree | 042ecae7db862b934180566b16645969987343de /src/net/vlan.c | |
parent | f12fcd53b1b661b5bfe7b5048398225297133b95 (diff) | |
download | ipxe-6fd09b541fbc426057661c7e0da4f39000b6803e.zip ipxe-6fd09b541fbc426057661c7e0da4f39000b6803e.tar.gz ipxe-6fd09b541fbc426057661c7e0da4f39000b6803e.tar.bz2 |
[vlan] Add support for IEEE 802.1Q VLANs
Originally-implemented-by: michael-dev@fami-braun.de
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/net/vlan.c')
-rw-r--r-- | src/net/vlan.c | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/src/net/vlan.c b/src/net/vlan.c new file mode 100644 index 0000000..a764f30 --- /dev/null +++ b/src/net/vlan.c @@ -0,0 +1,465 @@ +/* + * Copyright (C) 2010 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <stdint.h> +#include <string.h> +#include <stdio.h> +#include <errno.h> +#include <byteswap.h> +#include <ipxe/features.h> +#include <ipxe/if_ether.h> +#include <ipxe/ethernet.h> +#include <ipxe/netdevice.h> +#include <ipxe/iobuf.h> +#include <ipxe/vlan.h> + +/** @file + * + * Virtual LANs + * + */ + +FEATURE ( FEATURE_PROTOCOL, "VLAN", DHCP_EB_FEATURE_VLAN, 1 ); + +struct net_protocol vlan_protocol __net_protocol; + +/** VLAN device private data */ +struct vlan_device { + /** Trunk network device */ + struct net_device *trunk; + /** VLAN tag */ + unsigned int tag; + /** Default priority */ + unsigned int priority; +}; + +/** + * Open VLAN device + * + * @v netdev Network device + * @ret rc Return status code + */ +static int vlan_open ( struct net_device *netdev ) { + struct vlan_device *vlan = netdev->priv; + + return netdev_open ( vlan->trunk ); +} + +/** + * Close VLAN device + * + * @v netdev Network device + */ +static void vlan_close ( struct net_device *netdev ) { + struct vlan_device *vlan = netdev->priv; + + netdev_close ( vlan->trunk ); +} + +/** + * Transmit packet on VLAN device + * + * @v netdev Network device + * @v iobuf I/O buffer + * @ret rc Return status code + */ +static int vlan_transmit ( struct net_device *netdev, + struct io_buffer *iobuf ) { + struct vlan_device *vlan = netdev->priv; + struct net_device *trunk = vlan->trunk; + struct ll_protocol *ll_protocol; + struct vlan_header *vlanhdr; + uint8_t ll_dest_copy[ETH_ALEN]; + uint8_t ll_source_copy[ETH_ALEN]; + const void *ll_dest; + const void *ll_source; + uint16_t net_proto; + int rc; + + /* Strip link-layer header and preserve link-layer header fields */ + ll_protocol = netdev->ll_protocol; + if ( ( rc = ll_protocol->pull ( netdev, iobuf, &ll_dest, &ll_source, + &net_proto ) ) != 0 ) { + DBGC ( netdev, "VLAN %s could not parse link-layer header: " + "%s\n", netdev->name, strerror ( rc ) ); + return rc; + } + memcpy ( ll_dest_copy, ll_dest, ETH_ALEN ); + memcpy ( ll_source_copy, ll_source, ETH_ALEN ); + + /* Construct VLAN header */ + vlanhdr = iob_push ( iobuf, sizeof ( *vlanhdr ) ); + vlanhdr->tci = htons ( VLAN_TCI ( vlan->tag, vlan->priority ) ); + vlanhdr->net_proto = net_proto; + + /* Reclaim I/O buffer from VLAN device's TX queue */ + list_del ( &iobuf->list ); + + /* Transmit packet on trunk device */ + if ( ( rc = net_tx ( iob_disown ( iobuf ), trunk, &vlan_protocol, + ll_dest_copy, ll_source_copy ) ) != 0 ) { + DBGC ( netdev, "VLAN %s could not transmit: %s\n", + netdev->name, strerror ( rc ) ); + /* Cannot return an error status, since that would + * cause the I/O buffer to be double-freed. + */ + return 0; + } + + return 0; +} + +/** + * Poll VLAN device + * + * @v netdev Network device + */ +static void vlan_poll ( struct net_device *netdev ) { + struct vlan_device *vlan = netdev->priv; + + /* Poll trunk device */ + netdev_poll ( vlan->trunk ); +} + +/** + * Enable/disable interrupts on VLAN device + * + * @v netdev Network device + * @v enable Interrupts should be enabled + */ +static void vlan_irq ( struct net_device *netdev, int enable ) { + struct vlan_device *vlan = netdev->priv; + + /* Enable/disable interrupts on trunk device. This is not at + * all robust, but there is no sensible course of action + * available. + */ + netdev_irq ( vlan->trunk, enable ); +} + +/** VLAN device operations */ +static struct net_device_operations vlan_operations = { + .open = vlan_open, + .close = vlan_close, + .transmit = vlan_transmit, + .poll = vlan_poll, + .irq = vlan_irq, +}; + +/** + * Synchronise VLAN device + * + * @v netdev Network device + */ +static void vlan_sync ( struct net_device *netdev ) { + struct vlan_device *vlan = netdev->priv; + struct net_device *trunk = vlan->trunk; + + /* Synchronise link status */ + if ( netdev->link_rc != trunk->link_rc ) + netdev_link_err ( netdev, trunk->link_rc ); + + /* Synchronise open/closed status */ + if ( netdev_is_open ( trunk ) ) { + if ( ! netdev_is_open ( netdev ) ) + netdev_open ( netdev ); + } else { + if ( netdev_is_open ( netdev ) ) + netdev_close ( netdev ); + } +} + +/** + * Identify VLAN device + * + * @v trunk Trunk network device + * @v tag VLAN tag + * @ret netdev VLAN device, if any + */ +static struct net_device * vlan_find ( struct net_device *trunk, + uint16_t tag ) { + struct net_device *netdev; + struct vlan_device *vlan; + + for_each_netdev ( netdev ) { + if ( netdev->op != &vlan_operations ) + continue; + vlan = netdev->priv; + if ( ( vlan->trunk == trunk ) && ( vlan->tag == tag ) ) + return netdev; + } + return NULL; +} + +/** + * Process incoming VLAN packet + * + * @v iobuf I/O buffer + * @v trunk Trunk network device + * @v ll_dest Link-layer destination address + * @v ll_source Link-layer source address + * @ret rc Return status code + */ +static int vlan_rx ( struct io_buffer *iobuf, struct net_device *trunk, + const void *ll_dest, const void *ll_source ) { + struct vlan_header *vlanhdr = iobuf->data; + struct net_device *netdev; + struct ll_protocol *ll_protocol; + uint8_t ll_dest_copy[ETH_ALEN]; + uint8_t ll_source_copy[ETH_ALEN]; + uint16_t tag; + int rc; + + /* Sanity check */ + if ( iob_len ( iobuf ) < sizeof ( *vlanhdr ) ) { + DBGC ( trunk, "VLAN %s received underlength packet (%zd " + "bytes)\n", trunk->name, iob_len ( iobuf ) ); + rc = -EINVAL; + goto err_sanity; + } + + /* Identify VLAN device */ + tag = VLAN_TAG ( ntohs ( vlanhdr->tci ) ); + netdev = vlan_find ( trunk, tag ); + if ( ! netdev ) { + DBGC2 ( trunk, "VLAN %s received packet for unknown VLAN " + "%d\n", trunk->name, tag ); + rc = -EPIPE; + goto err_no_vlan; + } + + /* Strip VLAN header and preserve original link-layer header fields */ + iob_pull ( iobuf, sizeof ( *vlanhdr ) ); + ll_protocol = trunk->ll_protocol; + memcpy ( ll_dest_copy, ll_dest, ETH_ALEN ); + memcpy ( ll_source_copy, ll_source, ETH_ALEN ); + + /* Reconstruct link-layer header for VLAN device */ + ll_protocol = netdev->ll_protocol; + if ( ( rc = ll_protocol->push ( netdev, iobuf, ll_dest_copy, + ll_source_copy, + vlanhdr->net_proto ) ) != 0 ) { + DBGC ( netdev, "VLAN %s could not reconstruct link-layer " + "header: %s\n", netdev->name, strerror ( rc ) ); + goto err_ll_push; + } + + /* Enqueue packet on VLAN device */ + netdev_rx ( netdev, iob_disown ( iobuf ) ); + return 0; + + err_ll_push: + err_no_vlan: + err_sanity: + free_iob ( iobuf ); + return rc; +} + +/** VLAN protocol */ +struct net_protocol vlan_protocol __net_protocol = { + .name = "VLAN", + .net_proto = htons ( ETH_P_8021Q ), + .rx = vlan_rx, +}; + +/** + * Create VLAN device + * + * @v trunk Trunk network device + * @v tag VLAN tag + * @v priority Default VLAN priority + * @ret rc Return status code + * + * The VLAN device will be created as an Ethernet device. (We cannot + * simply clone the link layer of the trunk network device, because + * this link layer may expect the network device structure to contain + * some link-layer-private data.) The trunk network device must + * therefore have a link layer that is in some sense 'compatible' with + * Ethernet; specifically, it must have link-layer addresses that are + * the same length as Ethernet link-layer addresses. + */ +int vlan_create ( struct net_device *trunk, unsigned int tag, + unsigned int priority ) { + struct net_device *netdev; + struct vlan_device *vlan; + int rc; + + /* Sanity checks */ + if ( trunk->ll_protocol->ll_addr_len != ETH_ALEN ) { + DBGC ( trunk, "VLAN %s cannot create VLAN for %s device\n", + trunk->name, trunk->ll_protocol->name ); + rc = -ENOTTY; + goto err_sanity; + } + if ( ! VLAN_TAG_IS_VALID ( tag ) ) { + DBGC ( trunk, "VLAN %s cannot create VLAN with invalid tag " + "%d\n", trunk->name, tag ); + rc = -EINVAL; + goto err_sanity; + } + if ( ! VLAN_PRIORITY_IS_VALID ( priority ) ) { + DBGC ( trunk, "VLAN %s cannot create VLAN with invalid " + "priority %d\n", trunk->name, priority ); + rc = -EINVAL; + goto err_sanity; + } + if ( ( netdev = vlan_find ( trunk, tag ) ) != NULL ) { + DBGC ( netdev, "VLAN %s already exists\n", netdev->name ); + rc = -EEXIST; + goto err_sanity; + } + + /* Allocate and initialise structure */ + netdev = alloc_etherdev ( sizeof ( *vlan ) ); + if ( ! netdev ) { + rc = -ENOMEM; + goto err_alloc_etherdev; + } + netdev_init ( netdev, &vlan_operations ); + netdev->dev = trunk->dev; + memcpy ( netdev->hw_addr, trunk->ll_addr, ETH_ALEN ); + vlan = netdev->priv; + vlan->trunk = netdev_get ( trunk ); + vlan->tag = tag; + vlan->priority = priority; + + /* Construct VLAN device name */ + snprintf ( netdev->name, sizeof ( netdev->name ), "%s.%d", + trunk->name, vlan->tag ); + + /* Register VLAN device */ + if ( ( rc = register_netdev ( netdev ) ) != 0 ) { + DBGC ( netdev, "VLAN %s could not register: %s\n", + netdev->name, strerror ( rc ) ); + goto err_register; + } + + /* Synchronise with trunk device */ + vlan_sync ( netdev ); + + return 0; + + unregister_netdev ( netdev ); + err_register: + netdev_nullify ( netdev ); + netdev_put ( netdev ); + netdev_put ( trunk ); + err_alloc_etherdev: + err_sanity: + return rc; +} + +/** + * Destroy VLAN device + * + * @v netdev Network device + * @ret rc Return status code + */ +int vlan_destroy ( struct net_device *netdev ) { + struct vlan_device *vlan = netdev->priv; + struct net_device *trunk; + + /* Sanity check */ + if ( netdev->op != &vlan_operations ) { + DBGC ( netdev, "VLAN %s cannot destroy non-VLAN device\n", + netdev->name ); + return -ENOTTY; + } + + /* Remove VLAN device */ + unregister_netdev ( netdev ); + trunk = vlan->trunk; + netdev_nullify ( netdev ); + netdev_put ( netdev ); + netdev_put ( trunk ); + + return 0; +} + +/** + * Do nothing + * + * @v trunk Trunk network device + * @ret rc Return status code + */ +static int vlan_probe ( struct net_device *trunk __unused ) { + return 0; +} + +/** + * Handle trunk network device link state change + * + * @v trunk Trunk network device + */ +static void vlan_notify ( struct net_device *trunk ) { + struct net_device *netdev; + struct vlan_device *vlan; + + for_each_netdev ( netdev ) { + if ( netdev->op != &vlan_operations ) + continue; + vlan = netdev->priv; + if ( vlan->trunk == trunk ) + vlan_sync ( netdev ); + } +} + +/** + * Destroy first VLAN device for a given trunk + * + * @v trunk Trunk network device + * @ret found A VLAN device was found + */ +static int vlan_remove_first ( struct net_device *trunk ) { + struct net_device *netdev; + struct vlan_device *vlan; + + for_each_netdev ( netdev ) { + if ( netdev->op != &vlan_operations ) + continue; + vlan = netdev->priv; + if ( vlan->trunk == trunk ) { + vlan_destroy ( netdev ); + return 1; + } + } + return 0; +} + +/** + * Destroy all VLAN devices for a given trunk + * + * @v trunk Trunk network device + */ +static void vlan_remove ( struct net_device *trunk ) { + + /* Remove all VLAN devices attached to this trunk, safe + * against arbitrary net device removal. + */ + while ( vlan_remove_first ( trunk ) ) {} +} + +/** VLAN driver */ +struct net_driver vlan_driver __net_driver = { + .name = "VLAN", + .probe = vlan_probe, + .notify = vlan_notify, + .remove = vlan_remove, +}; |