diff options
Diffstat (limited to '')
| -rw-r--r-- | net/bridge/br_fdb.c | 1318 |
1 files changed, 1318 insertions, 0 deletions
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c new file mode 100644 index 000000000..8a6470a21 --- /dev/null +++ b/net/bridge/br_fdb.c @@ -0,0 +1,1318 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Forwarding database + * Linux ethernet bridge + * + * Authors: + * Lennert Buytenhek <buytenh@gnu.org> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/rculist.h> +#include <linux/spinlock.h> +#include <linux/times.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/jhash.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/atomic.h> +#include <asm/unaligned.h> +#include <linux/if_vlan.h> +#include <net/switchdev.h> +#include <trace/events/bridge.h> +#include "br_private.h" + +static const struct rhashtable_params br_fdb_rht_params = { + .head_offset = offsetof(struct net_bridge_fdb_entry, rhnode), + .key_offset = offsetof(struct net_bridge_fdb_entry, key), + .key_len = sizeof(struct net_bridge_fdb_key), + .automatic_shrinking = true, +}; + +static struct kmem_cache *br_fdb_cache __read_mostly; +static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr, u16 vid); +static void fdb_notify(struct net_bridge *br, + const struct net_bridge_fdb_entry *, int, bool); + +int __init br_fdb_init(void) +{ + br_fdb_cache = kmem_cache_create("bridge_fdb_cache", + sizeof(struct net_bridge_fdb_entry), + 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!br_fdb_cache) + return -ENOMEM; + + return 0; +} + +void br_fdb_fini(void) +{ + kmem_cache_destroy(br_fdb_cache); +} + +int br_fdb_hash_init(struct net_bridge *br) +{ + return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params); +} + +void br_fdb_hash_fini(struct net_bridge *br) +{ + rhashtable_destroy(&br->fdb_hash_tbl); +} + +/* if topology_changing then use forward_delay (default 15 sec) + * otherwise keep longer (default 5 minutes) + */ +static inline unsigned long hold_time(const struct net_bridge *br) +{ + return br->topology_change ? br->forward_delay : br->ageing_time; +} + +static inline int has_expired(const struct net_bridge *br, + const struct net_bridge_fdb_entry *fdb) +{ + return !test_bit(BR_FDB_STATIC, &fdb->flags) && + !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) && + time_before_eq(fdb->updated + hold_time(br), jiffies); +} + +static void fdb_rcu_free(struct rcu_head *head) +{ + struct net_bridge_fdb_entry *ent + = container_of(head, struct net_bridge_fdb_entry, rcu); + kmem_cache_free(br_fdb_cache, ent); +} + +static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl, + const unsigned char *addr, + __u16 vid) +{ + struct net_bridge_fdb_key key; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + key.vlan_id = vid; + memcpy(key.addr.addr, addr, sizeof(key.addr.addr)); + + return rhashtable_lookup(tbl, &key, br_fdb_rht_params); +} + +/* requires bridge hash_lock */ +static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br, + const unsigned char *addr, + __u16 vid) +{ + struct net_bridge_fdb_entry *fdb; + + lockdep_assert_held_once(&br->hash_lock); + + rcu_read_lock(); + fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); + rcu_read_unlock(); + + return fdb; +} + +struct net_device *br_fdb_find_port(const struct net_device *br_dev, + const unsigned char *addr, + __u16 vid) +{ + struct net_bridge_fdb_entry *f; + struct net_device *dev = NULL; + struct net_bridge *br; + + ASSERT_RTNL(); + + if (!netif_is_bridge_master(br_dev)) + return NULL; + + br = netdev_priv(br_dev); + rcu_read_lock(); + f = br_fdb_find_rcu(br, addr, vid); + if (f && f->dst) + dev = f->dst->dev; + rcu_read_unlock(); + + return dev; +} +EXPORT_SYMBOL_GPL(br_fdb_find_port); + +struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br, + const unsigned char *addr, + __u16 vid) +{ + return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); +} + +/* When a static FDB entry is added, the mac address from the entry is + * added to the bridge private HW address list and all required ports + * are then updated with the new information. + * Called under RTNL. + */ +static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr) +{ + int err; + struct net_bridge_port *p; + + ASSERT_RTNL(); + + list_for_each_entry(p, &br->port_list, list) { + if (!br_promisc_port(p)) { + err = dev_uc_add(p->dev, addr); + if (err) + goto undo; + } + } + + return; +undo: + list_for_each_entry_continue_reverse(p, &br->port_list, list) { + if (!br_promisc_port(p)) + dev_uc_del(p->dev, addr); + } +} + +/* When a static FDB entry is deleted, the HW address from that entry is + * also removed from the bridge private HW address list and updates all + * the ports with needed information. + * Called under RTNL. + */ +static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr) +{ + struct net_bridge_port *p; + + ASSERT_RTNL(); + + list_for_each_entry(p, &br->port_list, list) { + if (!br_promisc_port(p)) + dev_uc_del(p->dev, addr); + } +} + +static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f, + bool swdev_notify) +{ + trace_fdb_delete(br, f); + + if (test_bit(BR_FDB_STATIC, &f->flags)) + fdb_del_hw_addr(br, f->key.addr.addr); + + hlist_del_init_rcu(&f->fdb_node); + rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode, + br_fdb_rht_params); + fdb_notify(br, f, RTM_DELNEIGH, swdev_notify); + call_rcu(&f->rcu, fdb_rcu_free); +} + +/* Delete a local entry if no other port had the same address. */ +static void fdb_delete_local(struct net_bridge *br, + const struct net_bridge_port *p, + struct net_bridge_fdb_entry *f) +{ + const unsigned char *addr = f->key.addr.addr; + struct net_bridge_vlan_group *vg; + const struct net_bridge_vlan *v; + struct net_bridge_port *op; + u16 vid = f->key.vlan_id; + + /* Maybe another port has same hw addr? */ + list_for_each_entry(op, &br->port_list, list) { + vg = nbp_vlan_group(op); + if (op != p && ether_addr_equal(op->dev->dev_addr, addr) && + (!vid || br_vlan_find(vg, vid))) { + f->dst = op; + clear_bit(BR_FDB_ADDED_BY_USER, &f->flags); + return; + } + } + + vg = br_vlan_group(br); + v = br_vlan_find(vg, vid); + /* Maybe bridge device has same hw addr? */ + if (p && ether_addr_equal(br->dev->dev_addr, addr) && + (!vid || (v && br_vlan_should_use(v)))) { + f->dst = NULL; + clear_bit(BR_FDB_ADDED_BY_USER, &f->flags); + return; + } + + fdb_delete(br, f, true); +} + +void br_fdb_find_delete_local(struct net_bridge *br, + const struct net_bridge_port *p, + const unsigned char *addr, u16 vid) +{ + struct net_bridge_fdb_entry *f; + + spin_lock_bh(&br->hash_lock); + f = br_fdb_find(br, addr, vid); + if (f && test_bit(BR_FDB_LOCAL, &f->flags) && + !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p) + fdb_delete_local(br, p, f); + spin_unlock_bh(&br->hash_lock); +} + +void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr) +{ + struct net_bridge_vlan_group *vg; + struct net_bridge_fdb_entry *f; + struct net_bridge *br = p->br; + struct net_bridge_vlan *v; + + spin_lock_bh(&br->hash_lock); + vg = nbp_vlan_group(p); + hlist_for_each_entry(f, &br->fdb_list, fdb_node) { + if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) && + !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) { + /* delete old one */ + fdb_delete_local(br, p, f); + + /* if this port has no vlan information + * configured, we can safely be done at + * this point. + */ + if (!vg || !vg->num_vlans) + goto insert; + } + } + +insert: + /* insert new address, may fail if invalid address or dup. */ + fdb_insert(br, p, newaddr, 0); + + if (!vg || !vg->num_vlans) + goto done; + + /* Now add entries for every VLAN configured on the port. + * This function runs under RTNL so the bitmap will not change + * from under us. + */ + list_for_each_entry(v, &vg->vlan_list, vlist) + fdb_insert(br, p, newaddr, v->vid); + +done: + spin_unlock_bh(&br->hash_lock); +} + +void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr) +{ + struct net_bridge_vlan_group *vg; + struct net_bridge_fdb_entry *f; + struct net_bridge_vlan *v; + + spin_lock_bh(&br->hash_lock); + + /* If old entry was unassociated with any port, then delete it. */ + f = br_fdb_find(br, br->dev->dev_addr, 0); + if (f && test_bit(BR_FDB_LOCAL, &f->flags) && + !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) + fdb_delete_local(br, NULL, f); + + fdb_insert(br, NULL, newaddr, 0); + vg = br_vlan_group(br); + if (!vg || !vg->num_vlans) + goto out; + /* Now remove and add entries for every VLAN configured on the + * bridge. This function runs under RTNL so the bitmap will not + * change from under us. + */ + list_for_each_entry(v, &vg->vlan_list, vlist) { + if (!br_vlan_should_use(v)) + continue; + f = br_fdb_find(br, br->dev->dev_addr, v->vid); + if (f && test_bit(BR_FDB_LOCAL, &f->flags) && + !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) + fdb_delete_local(br, NULL, f); + fdb_insert(br, NULL, newaddr, v->vid); + } +out: + spin_unlock_bh(&br->hash_lock); +} + +void br_fdb_cleanup(struct work_struct *work) +{ + struct net_bridge *br = container_of(work, struct net_bridge, + gc_work.work); + struct net_bridge_fdb_entry *f = NULL; + unsigned long delay = hold_time(br); + unsigned long work_delay = delay; + unsigned long now = jiffies; + + /* this part is tricky, in order to avoid blocking learning and + * consequently forwarding, we rely on rcu to delete objects with + * delayed freeing allowing us to continue traversing + */ + rcu_read_lock(); + hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { + unsigned long this_timer = f->updated + delay; + + if (test_bit(BR_FDB_STATIC, &f->flags) || + test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags)) { + if (test_bit(BR_FDB_NOTIFY, &f->flags)) { + if (time_after(this_timer, now)) + work_delay = min(work_delay, + this_timer - now); + else if (!test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, + &f->flags)) + fdb_notify(br, f, RTM_NEWNEIGH, false); + } + continue; + } + + if (time_after(this_timer, now)) { + work_delay = min(work_delay, this_timer - now); + } else { + spin_lock_bh(&br->hash_lock); + if (!hlist_unhashed(&f->fdb_node)) + fdb_delete(br, f, true); + spin_unlock_bh(&br->hash_lock); + } + } + rcu_read_unlock(); + + /* Cleanup minimum 10 milliseconds apart */ + work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10)); + mod_delayed_work(system_long_wq, &br->gc_work, work_delay); +} + +/* Completely flush all dynamic entries in forwarding database.*/ +void br_fdb_flush(struct net_bridge *br) +{ + struct net_bridge_fdb_entry *f; + struct hlist_node *tmp; + + spin_lock_bh(&br->hash_lock); + hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) { + if (!test_bit(BR_FDB_STATIC, &f->flags)) + fdb_delete(br, f, true); + } + spin_unlock_bh(&br->hash_lock); +} + +/* Flush all entries referring to a specific port. + * if do_all is set also flush static entries + * if vid is set delete all entries that match the vlan_id + */ +void br_fdb_delete_by_port(struct net_bridge *br, + const struct net_bridge_port *p, + u16 vid, + int do_all) +{ + struct net_bridge_fdb_entry *f; + struct hlist_node *tmp; + + spin_lock_bh(&br->hash_lock); + hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) { + if (f->dst != p) + continue; + + if (!do_all) + if (test_bit(BR_FDB_STATIC, &f->flags) || + (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags) && + !test_bit(BR_FDB_OFFLOADED, &f->flags)) || + (vid && f->key.vlan_id != vid)) + continue; + + if (test_bit(BR_FDB_LOCAL, &f->flags)) + fdb_delete_local(br, p, f); + else + fdb_delete(br, f, true); + } + spin_unlock_bh(&br->hash_lock); +} + +#if IS_ENABLED(CONFIG_ATM_LANE) +/* Interface used by ATM LANE hook to test + * if an addr is on some other bridge port */ +int br_fdb_test_addr(struct net_device *dev, unsigned char *addr) +{ + struct net_bridge_fdb_entry *fdb; + struct net_bridge_port *port; + int ret; + + rcu_read_lock(); + port = br_port_get_rcu(dev); + if (!port) + ret = 0; + else { + fdb = br_fdb_find_rcu(port->br, addr, 0); + ret = fdb && fdb->dst && fdb->dst->dev != dev && + fdb->dst->state == BR_STATE_FORWARDING; + } + rcu_read_unlock(); + + return ret; +} +#endif /* CONFIG_ATM_LANE */ + +/* + * Fill buffer with forwarding table records in + * the API format. + */ +int br_fdb_fillbuf(struct net_bridge *br, void *buf, + unsigned long maxnum, unsigned long skip) +{ + struct net_bridge_fdb_entry *f; + struct __fdb_entry *fe = buf; + int num = 0; + + memset(buf, 0, maxnum*sizeof(struct __fdb_entry)); + + rcu_read_lock(); + hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { + if (num >= maxnum) + break; + + if (has_expired(br, f)) + continue; + + /* ignore pseudo entry for local MAC address */ + if (!f->dst) + continue; + + if (skip) { + --skip; + continue; + } + + /* convert from internal format to API */ + memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN); + + /* due to ABI compat need to split into hi/lo */ + fe->port_no = f->dst->port_no; + fe->port_hi = f->dst->port_no >> 8; + + fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags); + if (!test_bit(BR_FDB_STATIC, &f->flags)) + fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated); + ++fe; + ++num; + } + rcu_read_unlock(); + + return num; +} + +static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br, + struct net_bridge_port *source, + const unsigned char *addr, + __u16 vid, + unsigned long flags) +{ + struct net_bridge_fdb_entry *fdb; + + fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); + if (fdb) { + memcpy(fdb->key.addr.addr, addr, ETH_ALEN); + fdb->dst = source; + fdb->key.vlan_id = vid; + fdb->flags = flags; + fdb->updated = fdb->used = jiffies; + if (rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, + &fdb->rhnode, + br_fdb_rht_params)) { + kmem_cache_free(br_fdb_cache, fdb); + fdb = NULL; + } else { + hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list); + } + } + return fdb; +} + +static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr, u16 vid) +{ + struct net_bridge_fdb_entry *fdb; + + if (!is_valid_ether_addr(addr)) + return -EINVAL; + + fdb = br_fdb_find(br, addr, vid); + if (fdb) { + /* it is okay to have multiple ports with same + * address, just use the first one. + */ + if (test_bit(BR_FDB_LOCAL, &fdb->flags)) + return 0; + br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n", + source ? source->dev->name : br->dev->name, addr, vid); + fdb_delete(br, fdb, true); + } + + fdb = fdb_create(br, source, addr, vid, + BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC)); + if (!fdb) + return -ENOMEM; + + fdb_add_hw_addr(br, addr); + fdb_notify(br, fdb, RTM_NEWNEIGH, true); + return 0; +} + +/* Add entry for local address of interface */ +int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr, u16 vid) +{ + int ret; + + spin_lock_bh(&br->hash_lock); + ret = fdb_insert(br, source, addr, vid); + spin_unlock_bh(&br->hash_lock); + return ret; +} + +/* returns true if the fdb was modified */ +static bool __fdb_mark_active(struct net_bridge_fdb_entry *fdb) +{ + return !!(test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags) && + test_and_clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)); +} + +void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, + const unsigned char *addr, u16 vid, unsigned long flags) +{ + struct net_bridge_fdb_entry *fdb; + + /* some users want to always flood. */ + if (hold_time(br) == 0) + return; + + fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid); + if (likely(fdb)) { + /* attempt to update an entry for a local interface */ + if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) { + if (net_ratelimit()) + br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n", + source->dev->name, addr, vid); + } else { + unsigned long now = jiffies; + bool fdb_modified = false; + + if (now != fdb->updated) { + fdb->updated = now; + fdb_modified = __fdb_mark_active(fdb); + } + + /* fastpath: update of existing entry */ + if (unlikely(source != fdb->dst && + !test_bit(BR_FDB_STICKY, &fdb->flags))) { + fdb->dst = source; + fdb_modified = true; + /* Take over HW learned entry */ + if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN, + &fdb->flags))) + clear_bit(BR_FDB_ADDED_BY_EXT_LEARN, + &fdb->flags); + } + + if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags))) + set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); + if (unlikely(fdb_modified)) { + trace_br_fdb_update(br, source, addr, vid, flags); + fdb_notify(br, fdb, RTM_NEWNEIGH, true); + } + } + } else { + spin_lock(&br->hash_lock); + fdb = fdb_create(br, source, addr, vid, flags); + if (fdb) { + trace_br_fdb_update(br, source, addr, vid, flags); + fdb_notify(br, fdb, RTM_NEWNEIGH, true); + } + /* else we lose race and someone else inserts + * it first, don't bother updating + */ + spin_unlock(&br->hash_lock); + } +} + +static int fdb_to_nud(const struct net_bridge *br, + const struct net_bridge_fdb_entry *fdb) +{ + if (test_bit(BR_FDB_LOCAL, &fdb->flags)) + return NUD_PERMANENT; + else if (test_bit(BR_FDB_STATIC, &fdb->flags)) + return NUD_NOARP; + else if (has_expired(br, fdb)) + return NUD_STALE; + else + return NUD_REACHABLE; +} + +static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br, + const struct net_bridge_fdb_entry *fdb, + u32 portid, u32 seq, int type, unsigned int flags) +{ + unsigned long now = jiffies; + struct nda_cacheinfo ci; + struct nlmsghdr *nlh; + struct ndmsg *ndm; + + nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags); + if (nlh == NULL) + return -EMSGSIZE; + + ndm = nlmsg_data(nlh); + ndm->ndm_family = AF_BRIDGE; + ndm->ndm_pad1 = 0; + ndm->ndm_pad2 = 0; + ndm->ndm_flags = 0; + ndm->ndm_type = 0; + ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex; + ndm->ndm_state = fdb_to_nud(br, fdb); + + if (test_bit(BR_FDB_OFFLOADED, &fdb->flags)) + ndm->ndm_flags |= NTF_OFFLOADED; + if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) + ndm->ndm_flags |= NTF_EXT_LEARNED; + if (test_bit(BR_FDB_STICKY, &fdb->flags)) + ndm->ndm_flags |= NTF_STICKY; + + if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr)) + goto nla_put_failure; + if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex)) + goto nla_put_failure; + ci.ndm_used = jiffies_to_clock_t(now - fdb->used); + ci.ndm_confirmed = 0; + ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated); + ci.ndm_refcnt = 0; + if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci)) + goto nla_put_failure; + + if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16), + &fdb->key.vlan_id)) + goto nla_put_failure; + + if (test_bit(BR_FDB_NOTIFY, &fdb->flags)) { + struct nlattr *nest = nla_nest_start(skb, NDA_FDB_EXT_ATTRS); + u8 notify_bits = FDB_NOTIFY_BIT; + + if (!nest) + goto nla_put_failure; + if (test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)) + notify_bits |= FDB_NOTIFY_INACTIVE_BIT; + + if (nla_put_u8(skb, NFEA_ACTIVITY_NOTIFY, notify_bits)) { + nla_nest_cancel(skb, nest); + goto nla_put_failure; + } + + nla_nest_end(skb, nest); + } + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static inline size_t fdb_nlmsg_size(void) +{ + return NLMSG_ALIGN(sizeof(struct ndmsg)) + + nla_total_size(ETH_ALEN) /* NDA_LLADDR */ + + nla_total_size(sizeof(u32)) /* NDA_MASTER */ + + nla_total_size(sizeof(u16)) /* NDA_VLAN */ + + nla_total_size(sizeof(struct nda_cacheinfo)) + + nla_total_size(0) /* NDA_FDB_EXT_ATTRS */ + + nla_total_size(sizeof(u8)); /* NFEA_ACTIVITY_NOTIFY */ +} + +static void fdb_notify(struct net_bridge *br, + const struct net_bridge_fdb_entry *fdb, int type, + bool swdev_notify) +{ + struct net *net = dev_net(br->dev); + struct sk_buff *skb; + int err = -ENOBUFS; + + if (swdev_notify) + br_switchdev_fdb_notify(fdb, type); + + skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC); + if (skb == NULL) + goto errout; + + err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0); + if (err < 0) { + /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC); + return; +errout: + rtnl_set_sk_err(net, RTNLGRP_NEIGH, err); +} + +/* Dump information about entries, in response to GETNEIGH */ +int br_fdb_dump(struct sk_buff *skb, + struct netlink_callback *cb, + struct net_device *dev, + struct net_device *filter_dev, + int *idx) +{ + struct net_bridge *br = netdev_priv(dev); + struct net_bridge_fdb_entry *f; + int err = 0; + + if (!(dev->priv_flags & IFF_EBRIDGE)) + return err; + + if (!filter_dev) { + err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx); + if (err < 0) + return err; + } + + rcu_read_lock(); + hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { + if (*idx < cb->args[2]) + goto skip; + if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) { + if (filter_dev != dev) + goto skip; + /* !f->dst is a special case for bridge + * It means the MAC belongs to the bridge + * Therefore need a little more filtering + * we only want to dump the !f->dst case + */ + if (f->dst) + goto skip; + } + if (!filter_dev && f->dst) + goto skip; + + err = fdb_fill_info(skb, br, f, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + RTM_NEWNEIGH, + NLM_F_MULTI); + if (err < 0) + break; +skip: + *idx += 1; + } + rcu_read_unlock(); + + return err; +} + +int br_fdb_get(struct sk_buff *skb, + struct nlattr *tb[], + struct net_device *dev, + const unsigned char *addr, + u16 vid, u32 portid, u32 seq, + struct netlink_ext_ack *extack) +{ + struct net_bridge *br = netdev_priv(dev); + struct net_bridge_fdb_entry *f; + int err = 0; + + rcu_read_lock(); + f = br_fdb_find_rcu(br, addr, vid); + if (!f) { + NL_SET_ERR_MSG(extack, "Fdb entry not found"); + err = -ENOENT; + goto errout; + } + + err = fdb_fill_info(skb, br, f, portid, seq, + RTM_NEWNEIGH, 0); +errout: + rcu_read_unlock(); + return err; +} + +/* returns true if the fdb is modified */ +static bool fdb_handle_notify(struct net_bridge_fdb_entry *fdb, u8 notify) +{ + bool modified = false; + + /* allow to mark an entry as inactive, usually done on creation */ + if ((notify & FDB_NOTIFY_INACTIVE_BIT) && + !test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags)) + modified = true; + + if ((notify & FDB_NOTIFY_BIT) && + !test_and_set_bit(BR_FDB_NOTIFY, &fdb->flags)) { + /* enabled activity tracking */ + modified = true; + } else if (!(notify & FDB_NOTIFY_BIT) && + test_and_clear_bit(BR_FDB_NOTIFY, &fdb->flags)) { + /* disabled activity tracking, clear notify state */ + clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags); + modified = true; + } + + return modified; +} + +/* Update (create or replace) forwarding database entry */ +static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, + const u8 *addr, struct ndmsg *ndm, u16 flags, u16 vid, + struct nlattr *nfea_tb[]) +{ + bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY); + bool refresh = !nfea_tb[NFEA_DONT_REFRESH]; + struct net_bridge_fdb_entry *fdb; + u16 state = ndm->ndm_state; + bool modified = false; + u8 notify = 0; + + /* If the port cannot learn allow only local and static entries */ + if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) && + !(source->state == BR_STATE_LEARNING || + source->state == BR_STATE_FORWARDING)) + return -EPERM; + + if (!source && !(state & NUD_PERMANENT)) { + pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n", + br->dev->name); + return -EINVAL; + } + + if (is_sticky && (state & NUD_PERMANENT)) + return -EINVAL; + + if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) { + notify = nla_get_u8(nfea_tb[NFEA_ACTIVITY_NOTIFY]); + if ((notify & ~BR_FDB_NOTIFY_SETTABLE_BITS) || + (notify & BR_FDB_NOTIFY_SETTABLE_BITS) == FDB_NOTIFY_INACTIVE_BIT) + return -EINVAL; + } + + fdb = br_fdb_find(br, addr, vid); + if (fdb == NULL) { + if (!(flags & NLM_F_CREATE)) + return -ENOENT; + + fdb = fdb_create(br, source, addr, vid, 0); + if (!fdb) + return -ENOMEM; + + modified = true; + } else { + if (flags & NLM_F_EXCL) + return -EEXIST; + + if (fdb->dst != source) { + fdb->dst = source; + modified = true; + } + } + + if (fdb_to_nud(br, fdb) != state) { + if (state & NUD_PERMANENT) { + set_bit(BR_FDB_LOCAL, &fdb->flags); + if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags)) + fdb_add_hw_addr(br, addr); + } else if (state & NUD_NOARP) { + clear_bit(BR_FDB_LOCAL, &fdb->flags); + if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags)) + fdb_add_hw_addr(br, addr); + } else { + clear_bit(BR_FDB_LOCAL, &fdb->flags); + if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags)) + fdb_del_hw_addr(br, addr); + } + + modified = true; + } + + if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) { + change_bit(BR_FDB_STICKY, &fdb->flags); + modified = true; + } + + if (fdb_handle_notify(fdb, notify)) + modified = true; + + set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); + + fdb->used = jiffies; + if (modified) { + if (refresh) + fdb->updated = jiffies; + fdb_notify(br, fdb, RTM_NEWNEIGH, true); + } + + return 0; +} + +static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br, + struct net_bridge_port *p, const unsigned char *addr, + u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[], + struct netlink_ext_ack *extack) +{ + int err = 0; + + if (ndm->ndm_flags & NTF_USE) { + if (!p) { + pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n", + br->dev->name); + return -EINVAL; + } + if (!nbp_state_should_learn(p)) + return 0; + + local_bh_disable(); + rcu_read_lock(); + br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER)); + rcu_read_unlock(); + local_bh_enable(); + } else if (ndm->ndm_flags & NTF_EXT_LEARNED) { + if (!p && !(ndm->ndm_state & NUD_PERMANENT)) { + NL_SET_ERR_MSG_MOD(extack, + "FDB entry towards bridge must be permanent"); + return -EINVAL; + } + err = br_fdb_external_learn_add(br, p, addr, vid, true); + } else { + spin_lock_bh(&br->hash_lock); + err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb); + spin_unlock_bh(&br->hash_lock); + } + + return err; +} + +static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = { + [NFEA_ACTIVITY_NOTIFY] = { .type = NLA_U8 }, + [NFEA_DONT_REFRESH] = { .type = NLA_FLAG }, +}; + +/* Add new permanent fdb entry with RTM_NEWNEIGH */ +int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[], + struct net_device *dev, + const unsigned char *addr, u16 vid, u16 nlh_flags, + struct netlink_ext_ack *extack) +{ + struct nlattr *nfea_tb[NFEA_MAX + 1], *attr; + struct net_bridge_vlan_group *vg; + struct net_bridge_port *p = NULL; + struct net_bridge_vlan *v; + struct net_bridge *br = NULL; + int err = 0; + + trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags); + + if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) { + pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state); + return -EINVAL; + } + + if (is_zero_ether_addr(addr)) { + pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n"); + return -EINVAL; + } + + if (dev->priv_flags & IFF_EBRIDGE) { + br = netdev_priv(dev); + vg = br_vlan_group(br); + } else { + p = br_port_get_rtnl(dev); + if (!p) { + pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n", + dev->name); + return -EINVAL; + } + br = p->br; + vg = nbp_vlan_group(p); + } + + if (tb[NDA_FDB_EXT_ATTRS]) { + attr = tb[NDA_FDB_EXT_ATTRS]; + err = nla_parse_nested(nfea_tb, NFEA_MAX, attr, + br_nda_fdb_pol, extack); + if (err) + return err; + } else { + memset(nfea_tb, 0, sizeof(struct nlattr *) * (NFEA_MAX + 1)); + } + + if (vid) { + v = br_vlan_find(vg, vid); + if (!v || !br_vlan_should_use(v)) { + pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name); + return -EINVAL; + } + + /* VID was specified, so use it. */ + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb, + extack); + } else { + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb, + extack); + if (err || !vg || !vg->num_vlans) + goto out; + + /* We have vlans configured on this port and user didn't + * specify a VLAN. To be nice, add/update entry for every + * vlan on this port. + */ + list_for_each_entry(v, &vg->vlan_list, vlist) { + if (!br_vlan_should_use(v)) + continue; + err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid, + nfea_tb, extack); + if (err) + goto out; + } + } + +out: + return err; +} + +static int fdb_delete_by_addr_and_port(struct net_bridge *br, + const struct net_bridge_port *p, + const u8 *addr, u16 vlan) +{ + struct net_bridge_fdb_entry *fdb; + + fdb = br_fdb_find(br, addr, vlan); + if (!fdb || fdb->dst != p) + return -ENOENT; + + fdb_delete(br, fdb, true); + + return 0; +} + +static int __br_fdb_delete(struct net_bridge *br, + const struct net_bridge_port *p, + const unsigned char *addr, u16 vid) +{ + int err; + + spin_lock_bh(&br->hash_lock); + err = fdb_delete_by_addr_and_port(br, p, addr, vid); + spin_unlock_bh(&br->hash_lock); + + return err; +} + +/* Remove neighbor entry with RTM_DELNEIGH */ +int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[], + struct net_device *dev, + const unsigned char *addr, u16 vid) +{ + struct net_bridge_vlan_group *vg; + struct net_bridge_port *p = NULL; + struct net_bridge_vlan *v; + struct net_bridge *br; + int err; + + if (dev->priv_flags & IFF_EBRIDGE) { + br = netdev_priv(dev); + vg = br_vlan_group(br); + } else { + p = br_port_get_rtnl(dev); + if (!p) { + pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n", + dev->name); + return -EINVAL; + } + vg = nbp_vlan_group(p); + br = p->br; + } + + if (vid) { + v = br_vlan_find(vg, vid); + if (!v) { + pr_info("bridge: RTM_DELNEIGH with unconfigured vlan %d on %s\n", vid, dev->name); + return -EINVAL; + } + + err = __br_fdb_delete(br, p, addr, vid); + } else { + err = -ENOENT; + err &= __br_fdb_delete(br, p, addr, 0); + if (!vg || !vg->num_vlans) + return err; + + list_for_each_entry(v, &vg->vlan_list, vlist) { + if (!br_vlan_should_use(v)) + continue; + err &= __br_fdb_delete(br, p, addr, v->vid); + } + } + + return err; +} + +int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p) +{ + struct net_bridge_fdb_entry *f, *tmp; + int err = 0; + + ASSERT_RTNL(); + + /* the key here is that static entries change only under rtnl */ + rcu_read_lock(); + hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { + /* We only care for static entries */ + if (!test_bit(BR_FDB_STATIC, &f->flags)) + continue; + err = dev_uc_add(p->dev, f->key.addr.addr); + if (err) + goto rollback; + } +done: + rcu_read_unlock(); + + return err; + +rollback: + hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) { + /* We only care for static entries */ + if (!test_bit(BR_FDB_STATIC, &tmp->flags)) + continue; + if (tmp == f) + break; + dev_uc_del(p->dev, tmp->key.addr.addr); + } + + goto done; +} + +void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p) +{ + struct net_bridge_fdb_entry *f; + + ASSERT_RTNL(); + + rcu_read_lock(); + hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { + /* We only care for static entries */ + if (!test_bit(BR_FDB_STATIC, &f->flags)) + continue; + + dev_uc_del(p->dev, f->key.addr.addr); + } + rcu_read_unlock(); +} + +int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, + const unsigned char *addr, u16 vid, + bool swdev_notify) +{ + struct net_bridge_fdb_entry *fdb; + bool modified = false; + int err = 0; + + trace_br_fdb_external_learn_add(br, p, addr, vid); + + spin_lock_bh(&br->hash_lock); + + fdb = br_fdb_find(br, addr, vid); + if (!fdb) { + unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN); + + if (swdev_notify) + flags |= BIT(BR_FDB_ADDED_BY_USER); + + if (!p) + flags |= BIT(BR_FDB_LOCAL); + + fdb = fdb_create(br, p, addr, vid, flags); + if (!fdb) { + err = -ENOMEM; + goto err_unlock; + } + fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify); + } else { + fdb->updated = jiffies; + + if (fdb->dst != p) { + fdb->dst = p; + modified = true; + } + + if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) { + /* Refresh entry */ + fdb->used = jiffies; + } else if (!test_bit(BR_FDB_ADDED_BY_USER, &fdb->flags)) { + /* Take over SW learned entry */ + set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags); + modified = true; + } + + if (swdev_notify) + set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); + + if (!p) + set_bit(BR_FDB_LOCAL, &fdb->flags); + + if (modified) + fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify); + } + +err_unlock: + spin_unlock_bh(&br->hash_lock); + + return err; +} + +int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p, + const unsigned char *addr, u16 vid, + bool swdev_notify) +{ + struct net_bridge_fdb_entry *fdb; + int err = 0; + + spin_lock_bh(&br->hash_lock); + + fdb = br_fdb_find(br, addr, vid); + if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) + fdb_delete(br, fdb, swdev_notify); + else + err = -ENOENT; + + spin_unlock_bh(&br->hash_lock); + + return err; +} + +void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p, + const unsigned char *addr, u16 vid, bool offloaded) +{ + struct net_bridge_fdb_entry *fdb; + + spin_lock_bh(&br->hash_lock); + + fdb = br_fdb_find(br, addr, vid); + if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags)) + change_bit(BR_FDB_OFFLOADED, &fdb->flags); + + spin_unlock_bh(&br->hash_lock); +} + +void br_fdb_clear_offload(const struct net_device *dev, u16 vid) +{ + struct net_bridge_fdb_entry *f; + struct net_bridge_port *p; + + ASSERT_RTNL(); + + p = br_port_get_rtnl(dev); + if (!p) + return; + + spin_lock_bh(&p->br->hash_lock); + hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) { + if (f->dst == p && f->key.vlan_id == vid) + clear_bit(BR_FDB_OFFLOADED, &f->flags); + } + spin_unlock_bh(&p->br->hash_lock); +} +EXPORT_SYMBOL_GPL(br_fdb_clear_offload); |