// 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 */ #include #include #include 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);