path: root/drivers/net/ipvlan/ipvlan_main.c

/* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.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.
 *
 */

#include "ipvlan.h"

static unsigned int ipvlan_netid __read_mostly;

struct ipvlan_netns {
	unsigned int ipvl_nf_hook_refcnt;
};

static const struct nf_hook_ops ipvl_nfops[] = {
	{
		.hook     = ipvlan_nf_input,
		.pf       = NFPROTO_IPV4,
		.hooknum  = NF_INET_LOCAL_IN,
		.priority = INT_MAX,
	},
#if IS_ENABLED(CONFIG_IPV6)
	{
		.hook     = ipvlan_nf_input,
		.pf       = NFPROTO_IPV6,
		.hooknum  = NF_INET_LOCAL_IN,
		.priority = INT_MAX,
	},
#endif
};

static const struct l3mdev_ops ipvl_l3mdev_ops = {
	.l3mdev_l3_rcv = ipvlan_l3_rcv,
};

static void ipvlan_adjust_mtu(struct ipvl_dev *ipvlan, struct net_device *dev)
{
	ipvlan->dev->mtu = dev->mtu;
}

static int ipvlan_register_nf_hook(struct net *net)
{
	struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);
	int err = 0;

	if (!vnet->ipvl_nf_hook_refcnt) {
		err = nf_register_net_hooks(net, ipvl_nfops,
					    ARRAY_SIZE(ipvl_nfops));
		if (!err)
			vnet->ipvl_nf_hook_refcnt = 1;
	} else {
		vnet->ipvl_nf_hook_refcnt++;
	}

	return err;
}

static void ipvlan_unregister_nf_hook(struct net *net)
{
	struct ipvlan_netns *vnet = net_generic(net, ipvlan_netid);

	if (WARN_ON(!vnet->ipvl_nf_hook_refcnt))
		return;

	vnet->ipvl_nf_hook_refcnt--;
	if (!vnet->ipvl_nf_hook_refcnt)
		nf_unregister_net_hooks(net, ipvl_nfops,
					ARRAY_SIZE(ipvl_nfops));
}

static int ipvlan_set_port_mode(struct ipvl_port *port, u16 nval,
				struct netlink_ext_ack *extack)
{
	struct ipvl_dev *ipvlan;
	struct net_device *mdev = port->dev;
	unsigned int flags;
	int err;

	ASSERT_RTNL();
	if (port->mode != nval) {
		list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
			flags = ipvlan->dev->flags;
			if (nval == IPVLAN_MODE_L3 || nval == IPVLAN_MODE_L3S) {
				err = dev_change_flags(ipvlan->dev,
						       flags | IFF_NOARP);
			} else {
				err = dev_change_flags(ipvlan->dev,
						       flags & ~IFF_NOARP);
			}
			if (unlikely(err))
				goto fail;
		}
		if (nval == IPVLAN_MODE_L3S) {
			/* New mode is L3S */
			err = ipvlan_register_nf_hook(read_pnet(&port->pnet));
			if (!err) {
				mdev->l3mdev_ops = &ipvl_l3mdev_ops;
				mdev->priv_flags |= IFF_L3MDEV_MASTER;
			} else
				goto fail;
		} else if (port->mode == IPVLAN_MODE_L3S) {
			/* Old mode was L3S */
			mdev->priv_flags &= ~IFF_L3MDEV_MASTER;
			ipvlan_unregister_nf_hook(read_pnet(&port->pnet));
			mdev->l3mdev_ops = NULL;
		}
		port->mode = nval;
	}
	return 0;

fail:
	/* Undo the flags changes that have been done so far. */
	list_for_each_entry_continue_reverse(ipvlan, &port->ipvlans, pnode) {
		flags = ipvlan->dev->flags;
		if (port->mode == IPVLAN_MODE_L3 ||
		    port->mode == IPVLAN_MODE_L3S)
			dev_change_flags(ipvlan->dev, flags | IFF_NOARP);
		else
			dev_change_flags(ipvlan->dev, flags & ~IFF_NOARP);
	}

	return err;
}

static int ipvlan_port_create(struct net_device *dev)
{
	struct ipvl_port *port;
	int err, idx;

	port = kzalloc(sizeof(struct ipvl_port), GFP_KERNEL);
	if (!port)
		return -ENOMEM;

	write_pnet(&port->pnet, dev_net(dev));
	port->dev = dev;
	port->mode = IPVLAN_MODE_L3;
	INIT_LIST_HEAD(&port->ipvlans);
	for (idx = 0; idx < IPVLAN_HASH_SIZE; idx++)
		INIT_HLIST_HEAD(&port->hlhead[idx]);

	skb_queue_head_init(&port->backlog