net: Introduce L3 Master device abstraction

L3 master devices allow users of the abstraction to influence FIB lookups
for enslaved devices. Current API provides a means for the master device
to return a specific FIB table for an enslaved device, to return an
rtable/custom dst and influence the OIF used for fib lookups.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2015-09-29 20:07:11 -07:00 committed by David S. Miller
parent 007979eaf9
commit 1b69c6d0ae
8 changed files with 246 additions and 0 deletions

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@ -6095,6 +6095,13 @@ F: Documentation/auxdisplay/ks0108
F: drivers/auxdisplay/ks0108.c
F: include/linux/ks0108.h
L3MDEV
M: David Ahern <dsa@cumulusnetworks.com>
L: netdev@vger.kernel.org
S: Maintained
F: net/l3mdev
F: include/net/l3mdev.h
LAPB module
L: linux-x25@vger.kernel.org
S: Orphan

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@ -1587,6 +1587,9 @@ struct net_device {
#ifdef CONFIG_NET_SWITCHDEV
const struct switchdev_ops *switchdev_ops;
#endif
#ifdef CONFIG_NET_L3_MASTER_DEV
const struct l3mdev_ops *l3mdev_ops;
#endif
const struct header_ops *header_ops;

125
include/net/l3mdev.h Normal file
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@ -0,0 +1,125 @@
/*
* 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
*/
struct l3mdev_ops {
u32 (*l3mdev_fib_table)(const struct net_device *dev);
struct rtable * (*l3mdev_get_rtable)(const struct net_device *dev,
const struct flowi4 *fl4);
};
#ifdef CONFIG_NET_L3_MASTER_DEV
int l3mdev_master_ifindex_rcu(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;
}
/* 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;
}
#else
static inline int l3mdev_master_ifindex_rcu(struct net_device *dev)
{
return 0;
}
static inline int l3mdev_master_ifindex(struct net_device *dev)
{
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;
}
#endif
#endif /* _NET_L3MDEV_H_ */

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@ -232,6 +232,7 @@ source "net/netlink/Kconfig"
source "net/mpls/Kconfig"
source "net/hsr/Kconfig"
source "net/switchdev/Kconfig"
source "net/l3mdev/Kconfig"
config RPS
bool

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@ -74,3 +74,6 @@ obj-$(CONFIG_HSR) += hsr/
ifneq ($(CONFIG_NET_SWITCHDEV),)
obj-y += switchdev/
endif
ifneq ($(CONFIG_NET_L3_MASTER_DEV),)
obj-y += l3mdev/
endif

10
net/l3mdev/Kconfig Normal file
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@ -0,0 +1,10 @@
#
# Configuration for L3 master device support
#
config NET_L3_MASTER_DEV
bool "L3 Master device support"
depends on INET || IPV6
---help---
This module provides glue between core networking code and device
drivers to support L3 master devices like VRF.

5
net/l3mdev/Makefile Normal file
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@ -0,0 +1,5 @@
#
# Makefile for the L3 device API
#
obj-$(CONFIG_NET_L3_MASTER_DEV) += l3mdev.o

92
net/l3mdev/l3mdev.c Normal file
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@ -0,0 +1,92 @@
/*
* 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(struct net_device *dev)
{
int ifindex = 0;
if (!dev)
return 0;
if (netif_is_l3_master(dev)) {
ifindex = dev->ifindex;
} else if (dev->flags & IFF_SLAVE) {
struct net_device *master;
master = netdev_master_upper_dev_get_rcu(dev);
if (master && netif_is_l3_master(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 (dev->flags & IFF_SLAVE) {
/* 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 && netif_is_l3_master(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);