/*
   * INET		802.1Q VLAN
   *		Ethernet-type device handling.
   *
   * Authors:	Ben Greear <greearb@candelatech.com>

   *              Please send support related email to: netdev@vger.kernel.org

   *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html

   *

   * Fixes:
   *              Fix for packet capture - Nick Eggleston <nick@dccinc.com>;
   *		Add HW acceleration hooks - David S. Miller <davem@redhat.com>;
   *		Correct all the locking - David S. Miller <davem@redhat.com>;
   *		Use hash table for VLAN groups - David S. Miller <davem@redhat.com>
   *
   *		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,
  				   __be16 vlan_proto, u16 vlan_id)

  {
  	struct net_device **array;

  	unsigned int pidx, vidx;

  	unsigned int size;
  
  	ASSERT_RTNL();

  	pidx  = vlan_proto_idx(vlan_proto);
  	vidx  = vlan_id / VLAN_GROUP_ARRAY_PART_LEN;
  	array = vg->vlan_devices_arrays[pidx][vidx];

  	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[pidx][vidx] = 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;

  	grp->nr_vlan_devs--;

  	if (vlan->flags & VLAN_FLAG_MVRP)
  		vlan_mvrp_request_leave(dev);

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

  	vlan_group_set_device(grp, vlan->vlan_proto, vlan_id, NULL);

  
  	netdev_upper_dev_unlink(real_dev, dev);

  	/* 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_mvrp_uninit_applicant(real_dev);

  		vlan_gvrp_uninit_applicant(real_dev);

  	}

  	/* 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->vlan_proto, vlan_id);

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

  }

  int vlan_check_real_dev(struct net_device *real_dev,
  			__be16 protocol, u16 vlan_id)

  {

  	const char *name = real_dev->name;

  	if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {

  		pr_info("VLANs not supported on %s
  ", name);

  		return -EOPNOTSUPP;

  	}

  	if (vlan_find_dev(real_dev, protocol, 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->vlan_proto, 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_mvrp_init_applicant(real_dev);
  		if (err < 0)
  			goto out_uninit_gvrp;

  	}

  	err = vlan_group_prealloc_vid(grp, vlan->vlan_proto, vlan_id);

  	if (err < 0)

  		goto out_uninit_mvrp;

  	vlan->nest_level = dev_get_nest_level(real_dev, is_vlan_dev) + 1;

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

  		goto out_uninit_mvrp;
  
  	err = netdev_upper_dev_link(real_dev, dev);
  	if (err)
  		goto out_unregister_netdev;

  	/* 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->vlan_proto, vlan_id, dev);

  	grp->nr_vlan_devs++;

  	return 0;

  out_unregister_netdev:
  	unregister_netdevice(dev);

  out_uninit_mvrp:
  	if (grp->nr_vlan_devs == 0)
  		vlan_mvrp_uninit_applicant(real_dev);
  out_uninit_gvrp:

  	if (grp->nr_vlan_devs == 0)

  		vlan_gvrp_uninit_applicant(real_dev);

  out_vid_del:

  	vlan_vid_del(real_dev, vlan->vlan_proto, 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 vlan_dev_priv *vlan;

  	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, htons(ETH_P_8021Q), 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,
  			       NET_NAME_UNKNOWN, 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 = vlan_dev_priv(new_dev);
  	vlan->vlan_proto = htons(ETH_P_8021Q);
  	vlan->vlan_id = vlan_id;
  	vlan->real_dev = real_dev;
  	vlan->dent = NULL;
  	vlan->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);

  	ether_addr_copy(vlan->real_dev_addr, dev->dev_addr);

  }

  static void vlan_transfer_features(struct net_device *dev,
  				   struct net_device *vlandev)
  {

  	struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);

  	vlandev->gso_max_size = dev->gso_max_size;

  	if (vlan_hw_offload_capable(dev->features, vlan->vlan_proto))

  		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 int __vlan_device_event(struct net_device *dev, unsigned long event)

  {

  	int err = 0;

  	switch (event) {
  	case NETDEV_CHANGENAME:
  		vlan_proc_rem_dev(dev);

  		err = vlan_proc_add_dev(dev);

  		break;

  	case NETDEV_REGISTER:

  		err = vlan_proc_add_dev(dev);

  		break;
  	case NETDEV_UNREGISTER:
  		vlan_proc_rem_dev(dev);
  		break;

  	}

  
  	return err;

  }

  static int vlan_device_event(struct notifier_block *unused, unsigned long event,
  			     void *ptr)

  {

  	struct net_device *dev = netdev_notifier_info_to_dev(ptr);

  	struct vlan_group *grp;

  	struct vlan_info *vlan_info;

  	int i, flgs;
  	struct net_device *vlandev;

  	struct vlan_dev_priv *vlan;

  	bool last = false;

  	LIST_HEAD(list);

  	if (is_vlan_dev(dev)) {
  		int err = __vlan_device_event(dev, event);
  
  		if (err)
  			return notifier_from_errno(err);
  	}

  	if ((event == NETDEV_UP) &&

  	    (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {

  		pr_info("adding VLAN 0 to HW filter on device %s
  ",

  			dev->name);

  		vlan_vid_add(dev, htons(ETH_P_8021Q), 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 */

  		vlan_group_for_each_dev(grp, i, vlandev)

  			netif_stacked_transfer_operstate(dev, vlandev);

  		break;

  	case NETDEV_CHANGEADDR:
  		/* Adjust unicast filters on underlying device */

  		vlan_group_for_each_dev(grp, i, vlandev) {

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

  			vlan_sync_address(dev, vlandev);
  		}

  		break;
  
  	case NETDEV_CHANGEMTU:

  		vlan_group_for_each_dev(grp, i, vlandev) {

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

  		break;

  	case NETDEV_FEAT_CHANGE:
  		/* Propagate device features to underlying device */

  		vlan_group_for_each_dev(grp, i, vlandev)

  			vlan_transfer_features(dev, vlandev);

  		break;

  	case NETDEV_DOWN: {
  		struct net_device *tmp;
  		LIST_HEAD(close_list);

  		if (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)

  			vlan_vid_del(dev, htons(ETH_P_8021Q), 0);

  		/* Put all VLANs for this dev in the down state too.  */

  		vlan_group_for_each_dev(grp, i, vlandev) {

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

  			vlan = vlan_dev_priv(vlandev);

  			if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))

  				list_add(&vlandev->close_list, &close_list);
  		}
  
  		dev_close_many(&close_list, false);
  
  		list_for_each_entry_safe(vlandev, tmp, &close_list, close_list) {

  			netif_stacked_transfer_operstate(dev, vlandev);

  			list_del_init(&vlandev->close_list);

  		}

  		list_del(&close_list);

  		break;

  	}

  	case NETDEV_UP:
  		/* Put all VLANs for this dev in the up state too.  */

  		vlan_group_for_each_dev(grp, i, vlandev) {

  			flgs = dev_get_flags(vlandev);

  			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;

  		vlan_group_for_each_dev(grp, i, vlandev) {

  			/* removal of last vid destroys vlan_info, abort

  			 * afterwards */

  			if (vlan_info->nr_vids == 1)

  				last = true;

  
  			unregister_vlan_dev(vlandev, &list);

  			if (last)
  				break;

  		}
  		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:

  	case NETDEV_RESEND_IGMP:

  		/* Propagate to vlan devices */

  		vlan_group_for_each_dev(grp, i, vlandev)

  			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
  ", 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_mvrp_init();

  	if (err < 0)
  		goto err4;

  	err = vlan_netlink_init();
  	if (err < 0)
  		goto err5;

  	vlan_ioctl_set(vlan_ioctl_handler);
  	return 0;

  err5:
  	vlan_mvrp_uninit();

  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_mvrp_uninit();

  	vlan_gvrp_uninit();

  }
  
  module_init(vlan_proto_init);
  module_exit(vlan_cleanup_module);

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