[vlan] Add support for IEEE 802.1Q VLANs

Originally-implemented-by: michael-dev@fami-braun.de
Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 465 insertions, 0 deletions

diff --git a/src/net/vlan.c b/src/net/vlan.c
new file mode 100644
index 00000000..a764f305
--- /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,
+};