// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/l3mdev/l3mdev.c - L3 master device implementation
* Copyright (c) 2015 Cumulus Networks
* Copyright (c) 2015 David Ahern <[email protected]>
*/
#include <linux/netdevice.h>
#include <net/fib_rules.h>
#include <net/l3mdev.h>
static DEFINE_SPINLOCK(l3mdev_lock);
struct l3mdev_handler {
lookup_by_table_id_t dev_lookup;
};
static struct l3mdev_handler l3mdev_handlers[L3MDEV_TYPE_MAX + 1];
static int l3mdev_check_type(enum l3mdev_type l3type)
{
if (l3type <= L3MDEV_TYPE_UNSPEC || l3type > L3MDEV_TYPE_MAX)
return -EINVAL;
return 0;
}
int l3mdev_table_lookup_register(enum l3mdev_type l3type,
lookup_by_table_id_t fn)
{
struct l3mdev_handler *hdlr;
int res;
res = l3mdev_check_type(l3type);
if (res)
return res;
hdlr = &l3mdev_handlers[l3type];
spin_lock(&l3mdev_lock);
if (hdlr->dev_lookup) {
res = -EBUSY;
goto unlock;
}
hdlr->dev_lookup = fn;
res = 0;
unlock:
spin_unlock(&l3mdev_lock);
return res;
}
EXPORT_SYMBOL_GPL(l3mdev_table_lookup_register);
void l3mdev_table_lookup_unregister(enum l3mdev_type l3type,
lookup_by_table_id_t fn)
{
struct l3mdev_handler *hdlr;
if (l3mdev_check_type(l3type))
return;
hdlr = &l3mdev_handlers[l3type];
spin_lock(&l3mdev_lock);
if (hdlr->dev_lookup == fn)
hdlr->dev_lookup = NULL;
spin_unlock(&l3mdev_lock);
}
EXPORT_SYMBOL_GPL(l3mdev_table_lookup_unregister);
int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type,
struct net *net, u32 table_id)
{
lookup_by_table_id_t lookup;
struct l3mdev_handler *hdlr;
int ifindex = -EINVAL;
int res;
res = l3mdev_check_type(l3type);
if (res)
return res;
hdlr = &l3mdev_handlers[l3type];
spin_lock(&l3mdev_lock);
lookup = hdlr->dev_lookup;
if (!lookup)
goto unlock;
ifindex = lookup(net, table_id);
unlock:
spin_unlock(&l3mdev_lock);
return ifindex;
}
EXPORT_SYMBOL_GPL(l3mdev_ifindex_lookup_by_table_id);
/**
* l3mdev_master_ifindex_rcu - 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_master_upper_ifindex_by_index_rcu - get index of upper l3 master
* device
* @net: network namespace for device index lookup
* @ifindex: targeted interface
*/
int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex)
{
struct net_device *dev;
dev = dev_get_by_index_rcu(net, ifindex);
while (dev && !netif_is_l3_master(dev))
dev = netdev_master_upper_dev_get_rcu(dev);
return dev ? dev->ifindex : 0;
}
EXPORT_SYMBOL_GPL(l3mdev_master_upper_ifindex_by_index_rcu);
/**
* l3mdev_fib_table_rcu - 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_link_scope_lookup - IPv6 route lookup based on flow for link
* local and multicast addresses
* @net: network namespace for device index lookup
* @fl6: IPv6 flow struct for lookup
* This function does not hold refcnt on the returned dst.
* Caller must hold rcu_read_lock().
*/
struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
struct flowi6 *fl6)
{
struct dst_entry *dst = NULL;
struct net_device *dev;
WARN_ON_ONCE(!rcu_read_lock_held());
if (fl6->flowi6_oif) {
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_link_scope_lookup)
dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6);
}
return dst;
}
EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup);
/**
* l3mdev_fib_rule_match - Determine if flowi references an
* L3 master device
* @net: network namespace for device index lookup
* @fl: flow struct
* @arg: store the table the rule matched with here
*/
int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
struct fib_lookup_arg *arg)
{
struct net_device *dev;
int rc = 0;
/* update flow ensures flowi_l3mdev is set when relevant */
if (!fl->flowi_l3mdev)
return 0;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, fl->flowi_l3mdev);
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_fib_table) {
arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev);
rc = 1;
}
rcu_read_unlock();
return rc;
}
void l3mdev_update_flow(struct net *net, struct flowi *fl)
{
struct net_device *dev;
rcu_read_lock();
if (fl->flowi_oif) {
dev = dev_get_by_index_rcu(net, fl->flowi_oif);
if (dev) {
if (!fl->flowi_l3mdev)
fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);
/* oif set to L3mdev directs lookup to its table;
* reset to avoid oif match in fib_lookup
*/
if (netif_is_l3_master(dev))
fl->flowi_oif = 0;
goto out;
}
}
if (fl->flowi_iif > LOOPBACK_IFINDEX && !fl->flowi_l3mdev) {
dev = dev_get_by_index_rcu(net, fl->flowi_iif);
if (dev)
fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev);
}
out:
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(l3mdev_update_flow);
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