1/*
 2 * net/l3mdev/l3mdev.c - L3 master device implementation
 3 * Copyright (c) 2015 Cumulus Networks
 4 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
 5 *
 6 * This program is free software; you can redistribute it and/or modify
 7 * it under the terms of the GNU General Public License as published by
 8 * the Free Software Foundation; either version 2 of the License, or
 9 * (at your option) any later version.
10 */
11
12#include <linux/netdevice.h>
13#include <net/l3mdev.h>
14
15/**
16 *	l3mdev_master_ifindex - get index of L3 master device
17 *	@dev: targeted interface
18 */
19
20int l3mdev_master_ifindex_rcu(const struct net_device *dev)
21{
22	int ifindex = 0;
23
24	if (!dev)
25		return 0;
26
27	if (netif_is_l3_master(dev)) {
28		ifindex = dev->ifindex;
29	} else if (netif_is_l3_slave(dev)) {
30		struct net_device *master;
31		struct net_device *_dev = (struct net_device *)dev;
32
33		/* netdev_master_upper_dev_get_rcu calls
34		 * list_first_or_null_rcu to walk the upper dev list.
35		 * list_first_or_null_rcu does not handle a const arg. We aren't
36		 * making changes, just want the master device from that list so
37		 * typecast to remove the const
38		 */
39		master = netdev_master_upper_dev_get_rcu(_dev);
40		if (master)
41			ifindex = master->ifindex;
42	}
43
44	return ifindex;
45}
46EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu);
47
48/**
49 *	l3mdev_fib_table - get FIB table id associated with an L3
50 *                             master interface
51 *	@dev: targeted interface
52 */
53
54u32 l3mdev_fib_table_rcu(const struct net_device *dev)
55{
56	u32 tb_id = 0;
57
58	if (!dev)
59		return 0;
60
61	if (netif_is_l3_master(dev)) {
62		if (dev->l3mdev_ops->l3mdev_fib_table)
63			tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev);
64	} else if (netif_is_l3_slave(dev)) {
65		/* Users of netdev_master_upper_dev_get_rcu need non-const,
66		 * but current inet_*type functions take a const
67		 */
68		struct net_device *_dev = (struct net_device *) dev;
69		const struct net_device *master;
70
71		master = netdev_master_upper_dev_get_rcu(_dev);
72		if (master &&
73		    master->l3mdev_ops->l3mdev_fib_table)
74			tb_id = master->l3mdev_ops->l3mdev_fib_table(master);
75	}
76
77	return tb_id;
78}
79EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu);
80
81u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
82{
83	struct net_device *dev;
84	u32 tb_id = 0;
85
86	if (!ifindex)
87		return 0;
88
89	rcu_read_lock();
90
91	dev = dev_get_by_index_rcu(net, ifindex);
92	if (dev)
93		tb_id = l3mdev_fib_table_rcu(dev);
94
95	rcu_read_unlock();
96
97	return tb_id;
98}
99EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index);