linux/net/l3mdev/l3mdev.c
David Ahern 1ff23beebd net: l3mdev: Allow send on enslaved interface
Allow udp and raw sockets to send by oif that is an enslaved interface
versus the l3mdev/VRF device. For example, this allows BFD to use ifindex
from IP_PKTINFO on a receive to send a response without the need to
convert to the VRF index. It also allows ping and ping6 to work when
specifying an enslaved interface (e.g., ping -I swp1 <ip>) which is
a natural use case.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-09 22:33:52 -04:00

163 lines
3.9 KiB
C

/*
* net/l3mdev/l3mdev.c - L3 master device implementation
* Copyright (c) 2015 Cumulus Networks
* Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.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 <linux/netdevice.h>
#include <net/l3mdev.h>
/**
* l3mdev_master_ifindex - get index of L3 master device
* @dev: targeted interface
*/
int l3mdev_master_ifindex_rcu(const struct net_device *dev)
{
int ifindex = 0;
if (!dev)
return 0;
if (netif_is_l3_master(dev)) {
ifindex = dev->ifindex;
} else if (netif_is_l3_slave(dev)) {
struct net_device *master;
struct net_device *_dev = (struct net_device *)dev;
/* netdev_master_upper_dev_get_rcu calls
* list_first_or_null_rcu to walk the upper dev list.
* list_first_or_null_rcu does not handle a const arg. We aren't
* making changes, just want the master device from that list so
* typecast to remove the const
*/
master = netdev_master_upper_dev_get_rcu(_dev);
if (master)
ifindex = master->ifindex;
}
return ifindex;
}
EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu);
/**
* l3mdev_fib_table - get FIB table id associated with an L3
* master interface
* @dev: targeted interface
*/
u32 l3mdev_fib_table_rcu(const struct net_device *dev)
{
u32 tb_id = 0;
if (!dev)
return 0;
if (netif_is_l3_master(dev)) {
if (dev->l3mdev_ops->l3mdev_fib_table)
tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev);
} else if (netif_is_l3_slave(dev)) {
/* Users of netdev_master_upper_dev_get_rcu need non-const,
* but current inet_*type functions take a const
*/
struct net_device *_dev = (struct net_device *) dev;
const struct net_device *master;
master = netdev_master_upper_dev_get_rcu(_dev);
if (master &&
master->l3mdev_ops->l3mdev_fib_table)
tb_id = master->l3mdev_ops->l3mdev_fib_table(master);
}
return tb_id;
}
EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu);
u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
u32 tb_id = 0;
if (!ifindex)
return 0;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
tb_id = l3mdev_fib_table_rcu(dev);
rcu_read_unlock();
return tb_id;
}
EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index);
/**
* l3mdev_get_rt6_dst - IPv6 route lookup based on flow. Returns
* cached route for L3 master device if relevant
* to flow
* @net: network namespace for device index lookup
* @fl6: IPv6 flow struct for lookup
*/
struct dst_entry *l3mdev_get_rt6_dst(struct net *net,
const struct flowi6 *fl6)
{
struct dst_entry *dst = NULL;
struct net_device *dev;
if (fl6->flowi6_oif) {
rcu_read_lock();
dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
if (dev && netif_is_l3_slave(dev))
dev = netdev_master_upper_dev_get_rcu(dev);
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_get_rt6_dst)
dst = dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6);
rcu_read_unlock();
}
return dst;
}
EXPORT_SYMBOL_GPL(l3mdev_get_rt6_dst);
/**
* l3mdev_get_saddr - get source address for a flow based on an interface
* enslaved to an L3 master device
* @net: network namespace for device index lookup
* @ifindex: Interface index
* @fl4: IPv4 flow struct
*/
int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4)
{
struct net_device *dev;
int rc = 0;
if (ifindex) {
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev && netif_is_l3_slave(dev))
dev = netdev_master_upper_dev_get_rcu(dev);
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_get_saddr)
rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
rcu_read_unlock();
}
return rc;
}
EXPORT_SYMBOL_GPL(l3mdev_get_saddr);