// 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 <dsa@cumulusnetworks.com> */ #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);