net/8021q/vlan.c - kernel/common - Git at Google

 /*
  * INET		802.1Q VLAN
  *		Ethernet-type device handling.
  *
  * Authors:	Ben Greear <[email protected]>
  *              Please send support related email to: [email protected]
  *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
  *
  * Fixes:
  *              Fix for packet capture - Nick Eggleston <[email protected]>;
  *		Add HW acceleration hooks - David S. Miller <[email protected]>;
  *		Correct all the locking - David S. Miller <[email protected]>;
  *		Use hash table for VLAN groups - David S. Miller <[email protected]>
  *
  *		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.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/capability.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/rculist.h>
 #include <net/p8022.h>
 #include <net/arp.h>
 #include <linux/rtnetlink.h>
 #include <linux/notifier.h>
 #include <net/rtnetlink.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <asm/uaccess.h>

 #include <linux/if_vlan.h>
 #include "vlan.h"
 #include "vlanproc.h"

 #define DRV_VERSION "1.8"

 /* Global VLAN variables */

 int vlan_net_id __read_mostly;

 const char vlan_fullname[] = "802.1Q VLAN Support";
 const char vlan_version[] = DRV_VERSION;

 /* End of global variables definitions. */

 static int vlan_group_prealloc_vid(struct vlan_group *vg, u16 vlan_id)
 {
 	struct net_device **array;
 	unsigned int size;

 	ASSERT_RTNL();

 	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 	if (array != NULL)
 		return 0;

 	size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
 	array = kzalloc(size, GFP_KERNEL);
 	if (array == NULL)
 		return -ENOBUFS;

 	vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN] = array;
 	return 0;
 }

 void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev = vlan->real_dev;
 	struct vlan_info *vlan_info;
 	struct vlan_group *grp;
 	u16 vlan_id = vlan->vlan_id;

 	ASSERT_RTNL();

 	vlan_info = rtnl_dereference(real_dev->vlan_info);
 	BUG_ON(!vlan_info);

 	grp = &vlan_info->grp;

 	/* Take it out of our own structures, but be sure to interlock with
 	 * HW accelerating devices or SW vlan input packet processing if
 	 * VLAN is not 0 (leave it there for 802.1p).
 	 */
 	if (vlan_id)
 		vlan_vid_del(real_dev, vlan_id);

 	grp->nr_vlan_devs--;

 	if (vlan->flags & VLAN_FLAG_GVRP)
 		vlan_gvrp_request_leave(dev);

 	vlan_group_set_device(grp, vlan_id, NULL);
 	/* Because unregister_netdevice_queue() makes sure at least one rcu
 	 * grace period is respected before device freeing,
 	 * we dont need to call synchronize_net() here.
 	 */
 	unregister_netdevice_queue(dev, head);

 	if (grp->nr_vlan_devs == 0)
 		vlan_gvrp_uninit_applicant(real_dev);

 	/* Get rid of the vlan's reference to real_dev */
 	dev_put(real_dev);
 }

 int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id)
 {
 	const char *name = real_dev->name;
 	const struct net_device_ops *ops = real_dev->netdev_ops;

 	if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
 		pr_info("VLANs not supported on %s\n", name);
 		return -EOPNOTSUPP;
 	}

 	if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
 	    (!ops->ndo_vlan_rx_add_vid || !ops->ndo_vlan_rx_kill_vid)) {
 		pr_info("Device %s has buggy VLAN hw accel\n", name);
 		return -EOPNOTSUPP;
 	}

 	if (vlan_find_dev(real_dev, vlan_id) != NULL)
 		return -EEXIST;

 	return 0;
 }

 int register_vlan_dev(struct net_device *dev)
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev = vlan->real_dev;
 	u16 vlan_id = vlan->vlan_id;
 	struct vlan_info *vlan_info;
 	struct vlan_group *grp;
 	int err;

 	err = vlan_vid_add(real_dev, vlan_id);
 	if (err)
 		return err;

 	vlan_info = rtnl_dereference(real_dev->vlan_info);
 	/* vlan_info should be there now. vlan_vid_add took care of it */
 	BUG_ON(!vlan_info);

 	grp = &vlan_info->grp;
 	if (grp->nr_vlan_devs == 0) {
 		err = vlan_gvrp_init_applicant(real_dev);
 		if (err < 0)
 			goto out_vid_del;
 	}

 	err = vlan_group_prealloc_vid(grp, vlan_id);
 	if (err < 0)
 		goto out_uninit_applicant;

 	err = register_netdevice(dev);
 	if (err < 0)
 		goto out_uninit_applicant;

 	/* Account for reference in struct vlan_dev_priv */
 	dev_hold(real_dev);

 	netif_stacked_transfer_operstate(real_dev, dev);
 	linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */

 	/* So, got the sucker initialized, now lets place
 	 * it into our local structure.
 	 */
 	vlan_group_set_device(grp, vlan_id, dev);
 	grp->nr_vlan_devs++;

 	return 0;

 out_uninit_applicant:
 	if (grp->nr_vlan_devs == 0)
 		vlan_gvrp_uninit_applicant(real_dev);
 out_vid_del:
 	vlan_vid_del(real_dev, vlan_id);
 	return err;
 }

 /*  Attach a VLAN device to a mac address (ie Ethernet Card).
  *  Returns 0 if the device was created or a negative error code otherwise.
  */
 static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
 {
 	struct net_device *new_dev;
 	struct net *net = dev_net(real_dev);
 	struct vlan_net *vn = net_generic(net, vlan_net_id);
 	char name[IFNAMSIZ];
 	int err;

 	if (vlan_id >= VLAN_VID_MASK)
 		return -ERANGE;

 	err = vlan_check_real_dev(real_dev, vlan_id);
 	if (err < 0)
 		return err;

 	/* Gotta set up the fields for the device. */
 	switch (vn->name_type) {
 	case VLAN_NAME_TYPE_RAW_PLUS_VID:
 		/* name will look like:	 eth1.0005 */
 		snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, vlan_id);
 		break;
 	case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
 		/* Put our vlan.VID in the name.
 		 * Name will look like:	 vlan5
 		 */
 		snprintf(name, IFNAMSIZ, "vlan%i", vlan_id);
 		break;
 	case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
 		/* Put our vlan.VID in the name.
 		 * Name will look like:	 eth0.5
 		 */
 		snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, vlan_id);
 		break;
 	case VLAN_NAME_TYPE_PLUS_VID:
 		/* Put our vlan.VID in the name.
 		 * Name will look like:	 vlan0005
 		 */
 	default:
 		snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
 	}

 	new_dev = alloc_netdev(sizeof(struct vlan_dev_priv), name, vlan_setup);

 	if (new_dev == NULL)
 		return -ENOBUFS;

 	dev_net_set(new_dev, net);
 	/* need 4 bytes for extra VLAN header info,
 	 * hope the underlying device can handle it.
 	 */
 	new_dev->mtu = real_dev->mtu;
 	new_dev->priv_flags |= (real_dev->priv_flags & IFF_UNICAST_FLT);

 	vlan_dev_priv(new_dev)->vlan_id = vlan_id;
 	vlan_dev_priv(new_dev)->real_dev = real_dev;
 	vlan_dev_priv(new_dev)->dent = NULL;
 	vlan_dev_priv(new_dev)->flags = VLAN_FLAG_REORDER_HDR;

 	new_dev->rtnl_link_ops = &vlan_link_ops;
 	err = register_vlan_dev(new_dev);
 	if (err < 0)
 		goto out_free_newdev;

 	return 0;

 out_free_newdev:
 	free_netdev(new_dev);
 	return err;
 }

 static void vlan_sync_address(struct net_device *dev,
 			      struct net_device *vlandev)
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);

 	/* May be called without an actual change */
 	if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
 		return;

 	/* vlan address was different from the old address and is equal to
 	 * the new address */
 	if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
 	    ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
 		dev_uc_del(dev, vlandev->dev_addr);

 	/* vlan address was equal to the old address and is different from
 	 * the new address */
 	if (ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
 	    !ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
 		dev_uc_add(dev, vlandev->dev_addr);

 	memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
 }

 static void vlan_transfer_features(struct net_device *dev,
 				   struct net_device *vlandev)
 {
 	vlandev->gso_max_size = dev->gso_max_size;

 	if (dev->features & NETIF_F_HW_VLAN_TX)
 		vlandev->hard_header_len = dev->hard_header_len;
 	else
 		vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;

 #if IS_ENABLED(CONFIG_FCOE)
 	vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
 #endif

 	netdev_update_features(vlandev);
 }

 static void __vlan_device_event(struct net_device *dev, unsigned long event)
 {
 	switch (event) {
 	case NETDEV_CHANGENAME:
 		vlan_proc_rem_dev(dev);
 		if (vlan_proc_add_dev(dev) < 0)
 			pr_warn("failed to change proc name for %s\n",
 				dev->name);
 		break;
 	case NETDEV_REGISTER:
 		if (vlan_proc_add_dev(dev) < 0)
 			pr_warn("failed to add proc entry for %s\n", dev->name);
 		break;
 	case NETDEV_UNREGISTER:
 		vlan_proc_rem_dev(dev);
 		break;
 	}
 }

 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			     void *ptr)
 {
 	struct net_device *dev = ptr;
 	struct vlan_group *grp;
 	struct vlan_info *vlan_info;
 	int i, flgs;
 	struct net_device *vlandev;
 	struct vlan_dev_priv *vlan;
 	LIST_HEAD(list);

 	if (is_vlan_dev(dev))
 		__vlan_device_event(dev, event);

 	if ((event == NETDEV_UP) &&
 	    (dev->features & NETIF_F_HW_VLAN_FILTER)) {
 		pr_info("adding VLAN 0 to HW filter on device %s\n",
 			dev->name);
 		vlan_vid_add(dev, 0);
 	}

 	vlan_info = rtnl_dereference(dev->vlan_info);
 	if (!vlan_info)
 		goto out;
 	grp = &vlan_info->grp;

 	/* It is OK that we do not hold the group lock right now,
 	 * as we run under the RTNL lock.
 	 */

 	switch (event) {
 	case NETDEV_CHANGE:
 		/* Propagate real device state to vlan devices */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			netif_stacked_transfer_operstate(dev, vlandev);
 		}
 		break;

 	case NETDEV_CHANGEADDR:
 		/* Adjust unicast filters on underlying device */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			flgs = vlandev->flags;
 			if (!(flgs & IFF_UP))
 				continue;

 			vlan_sync_address(dev, vlandev);
 		}
 		break;

 	case NETDEV_CHANGEMTU:
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			if (vlandev->mtu <= dev->mtu)
 				continue;

 			dev_set_mtu(vlandev, dev->mtu);
 		}
 		break;

 	case NETDEV_FEAT_CHANGE:
 		/* Propagate device features to underlying device */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			vlan_transfer_features(dev, vlandev);
 		}

 		break;

 	case NETDEV_DOWN:
 		if (dev->features & NETIF_F_HW_VLAN_FILTER)
 			vlan_vid_del(dev, 0);

 		/* Put all VLANs for this dev in the down state too.  */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			flgs = vlandev->flags;
 			if (!(flgs & IFF_UP))
 				continue;

 			vlan = vlan_dev_priv(vlandev);
 			if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
 				dev_change_flags(vlandev, flgs & ~IFF_UP);
 			netif_stacked_transfer_operstate(dev, vlandev);
 		}
 		break;

 	case NETDEV_UP:
 		/* Put all VLANs for this dev in the up state too.  */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			flgs = vlandev->flags;
 			if (flgs & IFF_UP)
 				continue;

 			vlan = vlan_dev_priv(vlandev);
 			if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
 				dev_change_flags(vlandev, flgs | IFF_UP);
 			netif_stacked_transfer_operstate(dev, vlandev);
 		}
 		break;

 	case NETDEV_UNREGISTER:
 		/* twiddle thumbs on netns device moves */
 		if (dev->reg_state != NETREG_UNREGISTERING)
 			break;

 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			/* removal of last vid destroys vlan_info, abort
 			 * afterwards */
 			if (vlan_info->nr_vids == 1)
 				i = VLAN_N_VID;

 			unregister_vlan_dev(vlandev, &list);
 		}
 		unregister_netdevice_many(&list);
 		break;

 	case NETDEV_PRE_TYPE_CHANGE:
 		/* Forbid underlaying device to change its type. */
 		if (vlan_uses_dev(dev))
 			return NOTIFY_BAD;
 		break;

 	case NETDEV_NOTIFY_PEERS:
 	case NETDEV_BONDING_FAILOVER:
 		/* Propagate to vlan devices */
 		for (i = 0; i < VLAN_N_VID; i++) {
 			vlandev = vlan_group_get_device(grp, i);
 			if (!vlandev)
 				continue;

 			call_netdevice_notifiers(event, vlandev);
 		}
 		break;
 	}

 out:
 	return NOTIFY_DONE;
 }

 static struct notifier_block vlan_notifier_block __read_mostly = {
 	.notifier_call = vlan_device_event,
 };

 /*
  *	VLAN IOCTL handler.
  *	o execute requested action or pass command to the device driver
  *   arg is really a struct vlan_ioctl_args __user *.
  */
 static int vlan_ioctl_handler(struct net *net, void __user *arg)
 {
 	int err;
 	struct vlan_ioctl_args args;
 	struct net_device *dev = NULL;

 	if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
 		return -EFAULT;

 	/* Null terminate this sucker, just in case. */
 	args.device1[23] = 0;
 	args.u.device2[23] = 0;

 	rtnl_lock();

 	switch (args.cmd) {
 	case SET_VLAN_INGRESS_PRIORITY_CMD:
 	case SET_VLAN_EGRESS_PRIORITY_CMD:
 	case SET_VLAN_FLAG_CMD:
 	case ADD_VLAN_CMD:
 	case DEL_VLAN_CMD:
 	case GET_VLAN_REALDEV_NAME_CMD:
 	case GET_VLAN_VID_CMD:
 		err = -ENODEV;
 		dev = __dev_get_by_name(net, args.device1);
 		if (!dev)
 			goto out;

 		err = -EINVAL;
 		if (args.cmd != ADD_VLAN_CMD && !is_vlan_dev(dev))
 			goto out;
 	}

 	switch (args.cmd) {
 	case SET_VLAN_INGRESS_PRIORITY_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		vlan_dev_set_ingress_priority(dev,
 					      args.u.skb_priority,
 					      args.vlan_qos);
 		err = 0;
 		break;

 	case SET_VLAN_EGRESS_PRIORITY_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		err = vlan_dev_set_egress_priority(dev,
 						   args.u.skb_priority,
 						   args.vlan_qos);
 		break;

 	case SET_VLAN_FLAG_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		err = vlan_dev_change_flags(dev,
 					    args.vlan_qos ? args.u.flag : 0,
 					    args.u.flag);
 		break;

 	case SET_VLAN_NAME_TYPE_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		if ((args.u.name_type >= 0) &&
 		    (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
 			struct vlan_net *vn;

 			vn = net_generic(net, vlan_net_id);
 			vn->name_type = args.u.name_type;
 			err = 0;
 		} else {
 			err = -EINVAL;
 		}
 		break;

 	case ADD_VLAN_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		err = register_vlan_device(dev, args.u.VID);
 		break;

 	case DEL_VLAN_CMD:
 		err = -EPERM;
 		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			break;
 		unregister_vlan_dev(dev, NULL);
 		err = 0;
 		break;

 	case GET_VLAN_REALDEV_NAME_CMD:
 		err = 0;
 		vlan_dev_get_realdev_name(dev, args.u.device2);
 		if (copy_to_user(arg, &args,
 				 sizeof(struct vlan_ioctl_args)))
 			err = -EFAULT;
 		break;

 	case GET_VLAN_VID_CMD:
 		err = 0;
 		args.u.VID = vlan_dev_vlan_id(dev);
 		if (copy_to_user(arg, &args,
 				 sizeof(struct vlan_ioctl_args)))
 		      err = -EFAULT;
 		break;

 	default:
 		err = -EOPNOTSUPP;
 		break;
 	}
 out:
 	rtnl_unlock();
 	return err;
 }

 static int __net_init vlan_init_net(struct net *net)
 {
 	struct vlan_net *vn = net_generic(net, vlan_net_id);
 	int err;

 	vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;

 	err = vlan_proc_init(net);

 	return err;
 }

 static void __net_exit vlan_exit_net(struct net *net)
 {
 	vlan_proc_cleanup(net);
 }

 static struct pernet_operations vlan_net_ops = {
 	.init = vlan_init_net,
 	.exit = vlan_exit_net,
 	.id   = &vlan_net_id,
 	.size = sizeof(struct vlan_net),
 };

 static int __init vlan_proto_init(void)
 {
 	int err;

 	pr_info("%s v%s\n", vlan_fullname, vlan_version);

 	err = register_pernet_subsys(&vlan_net_ops);
 	if (err < 0)
 		goto err0;

 	err = register_netdevice_notifier(&vlan_notifier_block);
 	if (err < 0)
 		goto err2;

 	err = vlan_gvrp_init();
 	if (err < 0)
 		goto err3;

 	err = vlan_netlink_init();
 	if (err < 0)
 		goto err4;

 	vlan_ioctl_set(vlan_ioctl_handler);
 	return 0;

 err4:
 	vlan_gvrp_uninit();
 err3:
 	unregister_netdevice_notifier(&vlan_notifier_block);
 err2:
 	unregister_pernet_subsys(&vlan_net_ops);
 err0:
 	return err;
 }

 static void __exit vlan_cleanup_module(void)
 {
 	vlan_ioctl_set(NULL);
 	vlan_netlink_fini();

 	unregister_netdevice_notifier(&vlan_notifier_block);

 	unregister_pernet_subsys(&vlan_net_ops);
 	rcu_barrier(); /* Wait for completion of call_rcu()'s */

 	vlan_gvrp_uninit();
 }

 module_init(vlan_proto_init);
 module_exit(vlan_cleanup_module);

 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
	/*
	* INET 802.1Q VLAN
	* Ethernet-type device handling.
	*
	* Authors: Ben Greear <[email protected]>
	* Please send support related email to: [email protected]
	* VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
	*
	* Fixes:
	* Fix for packet capture - Nick Eggleston <[email protected]>;
	* Add HW acceleration hooks - David S. Miller <[email protected]>;
	* Correct all the locking - David S. Miller <[email protected]>;
	* Use hash table for VLAN groups - David S. Miller <[email protected]>
	*
	* 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.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/capability.h>
	#include <linux/module.h>
	#include <linux/netdevice.h>
	#include <linux/skbuff.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/rculist.h>
	#include <net/p8022.h>
	#include <net/arp.h>
	#include <linux/rtnetlink.h>
	#include <linux/notifier.h>
	#include <net/rtnetlink.h>
	#include <net/net_namespace.h>
	#include <net/netns/generic.h>
	#include <asm/uaccess.h>

	#include <linux/if_vlan.h>
	#include "vlan.h"
	#include "vlanproc.h"

	#define DRV_VERSION "1.8"

	/* Global VLAN variables */

	int vlan_net_id __read_mostly;

	const char vlan_fullname[] = "802.1Q VLAN Support";
	const char vlan_version[] = DRV_VERSION;

	/* End of global variables definitions. */

	static int vlan_group_prealloc_vid(struct vlan_group *vg, u16 vlan_id)
	{
	struct net_device **array;
	unsigned int size;

	ASSERT_RTNL();

	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
	if (array != NULL)
	return 0;

	size = sizeof(struct net_device ) VLAN_GROUP_ARRAY_PART_LEN;
	array = kzalloc(size, GFP_KERNEL);
	if (array == NULL)
	return -ENOBUFS;

	vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN] = array;
	return 0;
	}

	void unregister_vlan_dev(struct net_device dev, struct list_head head)
	{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct net_device *real_dev = vlan->real_dev;
	struct vlan_info *vlan_info;
	struct vlan_group *grp;
	u16 vlan_id = vlan->vlan_id;

	ASSERT_RTNL();

	vlan_info = rtnl_dereference(real_dev->vlan_info);
	BUG_ON(!vlan_info);

	grp = &vlan_info->grp;

	/* Take it out of our own structures, but be sure to interlock with
	* HW accelerating devices or SW vlan input packet processing if
	* VLAN is not 0 (leave it there for 802.1p).
	*/
	if (vlan_id)
	vlan_vid_del(real_dev, vlan_id);

	grp->nr_vlan_devs--;

	if (vlan->flags & VLAN_FLAG_GVRP)
	vlan_gvrp_request_leave(dev);

	vlan_group_set_device(grp, vlan_id, NULL);
	/* Because unregister_netdevice_queue() makes sure at least one rcu
	* grace period is respected before device freeing,
	* we dont need to call synchronize_net() here.
	*/
	unregister_netdevice_queue(dev, head);

	if (grp->nr_vlan_devs == 0)
	vlan_gvrp_uninit_applicant(real_dev);

	/* Get rid of the vlan's reference to real_dev */
	dev_put(real_dev);
	}

	int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id)
	{
	const char *name = real_dev->name;
	const struct net_device_ops *ops = real_dev->netdev_ops;

	if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
	pr_info("VLANs not supported on %s\n", name);
	return -EOPNOTSUPP;
	}

	if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
	(!ops->ndo_vlan_rx_add_vid \|\| !ops->ndo_vlan_rx_kill_vid)) {
	pr_info("Device %s has buggy VLAN hw accel\n", name);
	return -EOPNOTSUPP;
	}

	if (vlan_find_dev(real_dev, vlan_id) != NULL)
	return -EEXIST;

	return 0;
	}

	int register_vlan_dev(struct net_device *dev)
	{
	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
	struct net_device *real_dev = vlan->real_dev;
	u16 vlan_id = vlan->vlan_id;
	struct vlan_info *vlan_info;
	struct vlan_group *grp;
	int err;

	err = vlan_vid_add(real_dev, vlan_id);
	if (err)
	return err;

	vlan_info = rtnl_dereference(real_dev->vlan_info);
	/* vlan_info should be there now. vlan_vid_add took care of it */
	BUG_ON(!vlan_info);

	grp = &vlan_info->grp;
	if (grp->nr_vlan_devs == 0) {
	err = vlan_gvrp_init_applicant(real_dev);
	if (err < 0)
	goto out_vid_del;
	}

	err = vlan_group_prealloc_vid(grp, vlan_id);
	if (err < 0)
	goto out_uninit_applicant;

	err = register_netdevice(dev);
	if (err < 0)
	goto out_uninit_applicant;

	/* Account for reference in struct vlan_dev_priv */
	dev_hold(real_dev);

	netif_stacked_transfer_operstate(real_dev, dev);
	linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */

	/* So, got the sucker initialized, now lets place
	* it into our local structure.
	*/
	vlan_group_set_device(grp, vlan_id, dev);
	grp->nr_vlan_devs++;

	return 0;

	out_uninit_applicant:
	if (grp->nr_vlan_devs == 0)
	vlan_gvrp_uninit_applicant(real_dev);
	out_vid_del:
	vlan_vid_del(real_dev, vlan_id);
	return err;
	}

	/* Attach a VLAN device to a mac address (ie Ethernet Card).
	* Returns 0 if the device was created or a negative error code otherwise.
	*/
	static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
	{
	struct net_device *new_dev;
	struct net *net = dev_net(real_dev);
	struct vlan_net *vn = net_generic(net, vlan_net_id);
	char name[IFNAMSIZ];
	int err;

	if (vlan_id >= VLAN_VID_MASK)
	return -ERANGE;

	err = vlan_check_real_dev(real_dev, vlan_id);
	if (err < 0)
	return err;

	/* Gotta set up the fields for the device. */
	switch (vn->name_type) {
	case VLAN_NAME_TYPE_RAW_PLUS_VID:
	/* name will look like: eth1.0005 */
	snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, vlan_id);
	break;
	case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
	/* Put our vlan.VID in the name.
	* Name will look like: vlan5
	*/
	snprintf(name, IFNAMSIZ, "vlan%i", vlan_id);
	break;
	case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
	/* Put our vlan.VID in the name.
	* Name will look like: eth0.5
	*/
	snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, vlan_id);
	break;
	case VLAN_NAME_TYPE_PLUS_VID:
	/* Put our vlan.VID in the name.
	* Name will look like: vlan0005
	*/
	default:
	snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
	}

	new_dev = alloc_netdev(sizeof(struct vlan_dev_priv), name, vlan_setup);

	if (new_dev == NULL)
	return -ENOBUFS;

	dev_net_set(new_dev, net);
	/* need 4 bytes for extra VLAN header info,
	* hope the underlying device can handle it.
	*/
	new_dev->mtu = real_dev->mtu;
	new_dev->priv_flags \|= (real_dev->priv_flags & IFF_UNICAST_FLT);

	vlan_dev_priv(new_dev)->vlan_id = vlan_id;
	vlan_dev_priv(new_dev)->real_dev = real_dev;
	vlan_dev_priv(new_dev)->dent = NULL;
	vlan_dev_priv(new_dev)->flags = VLAN_FLAG_REORDER_HDR;

	new_dev->rtnl_link_ops = &vlan_link_ops;
	err = register_vlan_dev(new_dev);
	if (err < 0)
	goto out_free_newdev;

	return 0;

	out_free_newdev:
	free_netdev(new_dev);
	return err;
	}

	static void vlan_sync_address(struct net_device *dev,
	struct net_device *vlandev)
	{
	struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);

	/* May be called without an actual change */
	if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
	return;

	/* vlan address was different from the old address and is equal to
	* the new address */
	if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
	ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
	dev_uc_del(dev, vlandev->dev_addr);

	/* vlan address was equal to the old address and is different from
	* the new address */
	if (ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
	!ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
	dev_uc_add(dev, vlandev->dev_addr);

	memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
	}

	static void vlan_transfer_features(struct net_device *dev,
	struct net_device *vlandev)
	{
	vlandev->gso_max_size = dev->gso_max_size;

	if (dev->features & NETIF_F_HW_VLAN_TX)
	vlandev->hard_header_len = dev->hard_header_len;
	else
	vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;

	#if IS_ENABLED(CONFIG_FCOE)
	vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
	#endif

	netdev_update_features(vlandev);
	}

	static void __vlan_device_event(struct net_device *dev, unsigned long event)
	{
	switch (event) {
	case NETDEV_CHANGENAME:
	vlan_proc_rem_dev(dev);
	if (vlan_proc_add_dev(dev) < 0)
	pr_warn("failed to change proc name for %s\n",
	dev->name);
	break;
	case NETDEV_REGISTER:
	if (vlan_proc_add_dev(dev) < 0)
	pr_warn("failed to add proc entry for %s\n", dev->name);
	break;
	case NETDEV_UNREGISTER:
	vlan_proc_rem_dev(dev);
	break;
	}
	}

	static int vlan_device_event(struct notifier_block *unused, unsigned long event,
	void *ptr)
	{
	struct net_device *dev = ptr;
	struct vlan_group *grp;
	struct vlan_info *vlan_info;
	int i, flgs;
	struct net_device *vlandev;
	struct vlan_dev_priv *vlan;
	LIST_HEAD(list);

	if (is_vlan_dev(dev))
	__vlan_device_event(dev, event);

	if ((event == NETDEV_UP) &&
	(dev->features & NETIF_F_HW_VLAN_FILTER)) {
	pr_info("adding VLAN 0 to HW filter on device %s\n",
	dev->name);
	vlan_vid_add(dev, 0);
	}

	vlan_info = rtnl_dereference(dev->vlan_info);
	if (!vlan_info)
	goto out;
	grp = &vlan_info->grp;

	/* It is OK that we do not hold the group lock right now,
	* as we run under the RTNL lock.
	*/

	switch (event) {
	case NETDEV_CHANGE:
	/* Propagate real device state to vlan devices */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	netif_stacked_transfer_operstate(dev, vlandev);
	}
	break;

	case NETDEV_CHANGEADDR:
	/* Adjust unicast filters on underlying device */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	flgs = vlandev->flags;
	if (!(flgs & IFF_UP))
	continue;

	vlan_sync_address(dev, vlandev);
	}
	break;

	case NETDEV_CHANGEMTU:
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	if (vlandev->mtu <= dev->mtu)
	continue;

	dev_set_mtu(vlandev, dev->mtu);
	}
	break;

	case NETDEV_FEAT_CHANGE:
	/* Propagate device features to underlying device */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	vlan_transfer_features(dev, vlandev);
	}

	break;

	case NETDEV_DOWN:
	if (dev->features & NETIF_F_HW_VLAN_FILTER)
	vlan_vid_del(dev, 0);

	/* Put all VLANs for this dev in the down state too. */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	flgs = vlandev->flags;
	if (!(flgs & IFF_UP))
	continue;

	vlan = vlan_dev_priv(vlandev);
	if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
	dev_change_flags(vlandev, flgs & ~IFF_UP);
	netif_stacked_transfer_operstate(dev, vlandev);
	}
	break;

	case NETDEV_UP:
	/* Put all VLANs for this dev in the up state too. */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	flgs = vlandev->flags;
	if (flgs & IFF_UP)
	continue;

	vlan = vlan_dev_priv(vlandev);
	if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
	dev_change_flags(vlandev, flgs \| IFF_UP);
	netif_stacked_transfer_operstate(dev, vlandev);
	}
	break;

	case NETDEV_UNREGISTER:
	/* twiddle thumbs on netns device moves */
	if (dev->reg_state != NETREG_UNREGISTERING)
	break;

	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	/* removal of last vid destroys vlan_info, abort
	* afterwards */
	if (vlan_info->nr_vids == 1)
	i = VLAN_N_VID;

	unregister_vlan_dev(vlandev, &list);
	}
	unregister_netdevice_many(&list);
	break;

	case NETDEV_PRE_TYPE_CHANGE:
	/* Forbid underlaying device to change its type. */
	if (vlan_uses_dev(dev))
	return NOTIFY_BAD;
	break;

	case NETDEV_NOTIFY_PEERS:
	case NETDEV_BONDING_FAILOVER:
	/* Propagate to vlan devices */
	for (i = 0; i < VLAN_N_VID; i++) {
	vlandev = vlan_group_get_device(grp, i);
	if (!vlandev)
	continue;

	call_netdevice_notifiers(event, vlandev);
	}
	break;
	}

	out:
	return NOTIFY_DONE;
	}

	static struct notifier_block vlan_notifier_block __read_mostly = {
	.notifier_call = vlan_device_event,
	};

	/*
	* VLAN IOCTL handler.
	* o execute requested action or pass command to the device driver
	* arg is really a struct vlan_ioctl_args __user *.
	*/
	static int vlan_ioctl_handler(struct net net, void __user arg)
	{
	int err;
	struct vlan_ioctl_args args;
	struct net_device *dev = NULL;

	if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
	return -EFAULT;

	/* Null terminate this sucker, just in case. */
	args.device1[23] = 0;
	args.u.device2[23] = 0;

	rtnl_lock();

	switch (args.cmd) {
	case SET_VLAN_INGRESS_PRIORITY_CMD:
	case SET_VLAN_EGRESS_PRIORITY_CMD:
	case SET_VLAN_FLAG_CMD:
	case ADD_VLAN_CMD:
	case DEL_VLAN_CMD:
	case GET_VLAN_REALDEV_NAME_CMD:
	case GET_VLAN_VID_CMD:
	err = -ENODEV;
	dev = __dev_get_by_name(net, args.device1);
	if (!dev)
	goto out;

	err = -EINVAL;
	if (args.cmd != ADD_VLAN_CMD && !is_vlan_dev(dev))
	goto out;
	}

	switch (args.cmd) {
	case SET_VLAN_INGRESS_PRIORITY_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	vlan_dev_set_ingress_priority(dev,
	args.u.skb_priority,
	args.vlan_qos);
	err = 0;
	break;

	case SET_VLAN_EGRESS_PRIORITY_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	err = vlan_dev_set_egress_priority(dev,
	args.u.skb_priority,
	args.vlan_qos);
	break;

	case SET_VLAN_FLAG_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	err = vlan_dev_change_flags(dev,
	args.vlan_qos ? args.u.flag : 0,
	args.u.flag);
	break;

	case SET_VLAN_NAME_TYPE_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	if ((args.u.name_type >= 0) &&
	(args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
	struct vlan_net *vn;

	vn = net_generic(net, vlan_net_id);
	vn->name_type = args.u.name_type;
	err = 0;
	} else {
	err = -EINVAL;
	}
	break;

	case ADD_VLAN_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	err = register_vlan_device(dev, args.u.VID);
	break;

	case DEL_VLAN_CMD:
	err = -EPERM;
	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
	break;
	unregister_vlan_dev(dev, NULL);
	err = 0;
	break;

	case GET_VLAN_REALDEV_NAME_CMD:
	err = 0;
	vlan_dev_get_realdev_name(dev, args.u.device2);
	if (copy_to_user(arg, &args,
	sizeof(struct vlan_ioctl_args)))
	err = -EFAULT;
	break;

	case GET_VLAN_VID_CMD:
	err = 0;
	args.u.VID = vlan_dev_vlan_id(dev);
	if (copy_to_user(arg, &args,
	sizeof(struct vlan_ioctl_args)))
	err = -EFAULT;
	break;

	default:
	err = -EOPNOTSUPP;
	break;
	}
	out:
	rtnl_unlock();
	return err;
	}

	static int __net_init vlan_init_net(struct net *net)
	{
	struct vlan_net *vn = net_generic(net, vlan_net_id);
	int err;

	vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;

	err = vlan_proc_init(net);

	return err;
	}

	static void __net_exit vlan_exit_net(struct net *net)
	{
	vlan_proc_cleanup(net);
	}

	static struct pernet_operations vlan_net_ops = {
	.init = vlan_init_net,
	.exit = vlan_exit_net,
	.id = &vlan_net_id,
	.size = sizeof(struct vlan_net),
	};

	static int __init vlan_proto_init(void)
	{
	int err;

	pr_info("%s v%s\n", vlan_fullname, vlan_version);

	err = register_pernet_subsys(&vlan_net_ops);
	if (err < 0)
	goto err0;

	err = register_netdevice_notifier(&vlan_notifier_block);
	if (err < 0)
	goto err2;

	err = vlan_gvrp_init();
	if (err < 0)
	goto err3;

	err = vlan_netlink_init();
	if (err < 0)
	goto err4;

	vlan_ioctl_set(vlan_ioctl_handler);
	return 0;

	err4:
	vlan_gvrp_uninit();
	err3:
	unregister_netdevice_notifier(&vlan_notifier_block);
	err2:
	unregister_pernet_subsys(&vlan_net_ops);
	err0:
	return err;
	}

	static void __exit vlan_cleanup_module(void)
	{
	vlan_ioctl_set(NULL);
	vlan_netlink_fini();

	unregister_netdevice_notifier(&vlan_notifier_block);

	unregister_pernet_subsys(&vlan_net_ops);
	rcu_barrier(); /* Wait for completion of call_rcu()'s */

	vlan_gvrp_uninit();
	}

	module_init(vlan_proto_init);
	module_exit(vlan_cleanup_module);

	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRV_VERSION);