remarkable-linux/include/net/l3mdev.h
David Ahern 74b20582ac net: l3mdev: Add hook in ip and ipv6
Currently the VRF driver uses the rx_handler to switch the skb device
to the VRF device. Switching the dev prior to the ip / ipv6 layer
means the VRF driver has to duplicate IP/IPv6 processing which adds
overhead and makes features such as retaining the ingress device index
more complicated than necessary.

This patch moves the hook to the L3 layer just after the first NF_HOOK
for PRE_ROUTING. This location makes exposing the original ingress device
trivial (next patch) and allows adding other NF_HOOKs to the VRF driver
in the future.

dev_queue_xmit_nit is exported so that the VRF driver can cycle the skb
with the switched device through the packet taps to maintain current
behavior (tcpdump can be used on either the vrf device or the enslaved
devices).

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-11 19:31:40 -04:00

242 lines
5.1 KiB
C

/*
* include/net/l3mdev.h - L3 master device API
* 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.
*/
#ifndef _NET_L3MDEV_H_
#define _NET_L3MDEV_H_
/**
* struct l3mdev_ops - l3mdev operations
*
* @l3mdev_fib_table: Get FIB table id to use for lookups
*
* @l3mdev_get_rtable: Get cached IPv4 rtable (dst_entry) for device
*
* @l3mdev_get_saddr: Get source address for a flow
*
* @l3mdev_get_rt6_dst: Get cached IPv6 rt6_info (dst_entry) for device
*/
struct l3mdev_ops {
u32 (*l3mdev_fib_table)(const struct net_device *dev);
struct sk_buff * (*l3mdev_l3_rcv)(struct net_device *dev,
struct sk_buff *skb, u16 proto);
/* IPv4 ops */
struct rtable * (*l3mdev_get_rtable)(const struct net_device *dev,
const struct flowi4 *fl4);
int (*l3mdev_get_saddr)(struct net_device *dev,
struct flowi4 *fl4);
/* IPv6 ops */
struct dst_entry * (*l3mdev_get_rt6_dst)(const struct net_device *dev,
const struct flowi6 *fl6);
};
#ifdef CONFIG_NET_L3_MASTER_DEV
int l3mdev_master_ifindex_rcu(const struct net_device *dev);
static inline int l3mdev_master_ifindex(struct net_device *dev)
{
int ifindex;
rcu_read_lock();
ifindex = l3mdev_master_ifindex_rcu(dev);
rcu_read_unlock();
return ifindex;
}
static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
int rc = 0;
if (likely(ifindex)) {
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
rc = l3mdev_master_ifindex_rcu(dev);
rcu_read_unlock();
}
return rc;
}
/* get index of an interface to use for FIB lookups. For devices
* enslaved to an L3 master device FIB lookups are based on the
* master index
*/
static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
{
return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
}
static inline int l3mdev_fib_oif(struct net_device *dev)
{
int oif;
rcu_read_lock();
oif = l3mdev_fib_oif_rcu(dev);
rcu_read_unlock();
return oif;
}
u32 l3mdev_fib_table_rcu(const struct net_device *dev);
u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
static inline u32 l3mdev_fib_table(const struct net_device *dev)
{
u32 tb_id;
rcu_read_lock();
tb_id = l3mdev_fib_table_rcu(dev);
rcu_read_unlock();
return tb_id;
}
static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
const struct flowi4 *fl4)
{
if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rtable)
return dev->l3mdev_ops->l3mdev_get_rtable(dev, fl4);
return NULL;
}
static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
{
struct net_device *dev;
bool rc = false;
if (ifindex == 0)
return false;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
rc = netif_is_l3_master(dev);
rcu_read_unlock();
return rc;
}
int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4);
struct dst_entry *l3mdev_get_rt6_dst(struct net *net, const struct flowi6 *fl6);
static inline
struct sk_buff *l3mdev_l3_rcv(struct sk_buff *skb, u16 proto)
{
struct net_device *master = NULL;
if (netif_is_l3_slave(skb->dev))
master = netdev_master_upper_dev_get_rcu(skb->dev);
else if (netif_is_l3_master(skb->dev))
master = skb->dev;
if (master && master->l3mdev_ops->l3mdev_l3_rcv)
skb = master->l3mdev_ops->l3mdev_l3_rcv(master, skb, proto);
return skb;
}
static inline
struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
{
return l3mdev_l3_rcv(skb, AF_INET);
}
static inline
struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
{
return l3mdev_l3_rcv(skb, AF_INET6);
}
#else
static inline int l3mdev_master_ifindex_rcu(const struct net_device *dev)
{
return 0;
}
static inline int l3mdev_master_ifindex(struct net_device *dev)
{
return 0;
}
static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
{
return 0;
}
static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
{
return dev ? dev->ifindex : 0;
}
static inline int l3mdev_fib_oif(struct net_device *dev)
{
return dev ? dev->ifindex : 0;
}
static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
{
return 0;
}
static inline u32 l3mdev_fib_table(const struct net_device *dev)
{
return 0;
}
static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
{
return 0;
}
static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
const struct flowi4 *fl4)
{
return NULL;
}
static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
{
return false;
}
static inline int l3mdev_get_saddr(struct net *net, int ifindex,
struct flowi4 *fl4)
{
return 0;
}
static inline
struct dst_entry *l3mdev_get_rt6_dst(struct net *net, const struct flowi6 *fl6)
{
return NULL;
}
static inline
struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
{
return skb;
}
static inline
struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
{
return skb;
}
#endif
#endif /* _NET_L3MDEV_H_ */