// 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; 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 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) { const struct net_bridge_port *dst = READ_ONCE(fdb->dst); 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 = dst ? 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(br, 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); } 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); } 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; int err; fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); if (!fdb) return NULL; memcpy(fdb->key.addr.addr, addr, ETH_ALEN); WRITE_ONCE(fdb->dst, source); fdb->key.vlan_id = vid; fdb->flags = flags; fdb->updated = fdb->used = jiffies; err = rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, &fdb->rhnode, br_fdb_rht_params); if (err) { kmem_cache_free(br_fdb_cache, fdb); return NULL; } hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list); return fdb; } static int fdb_add_local(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; } 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_add_local(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_add_local(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_add_local(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_add_local(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); } static bool __fdb_flush_matches(const struct net_bridge *br, const struct net_bridge_fdb_entry *f, const struct net_bridge_fdb_flush_desc *desc) { const struct net_bridge_port *dst = READ_ONCE(f->dst); int port_ifidx = dst ? dst->dev->ifindex : br->dev->ifindex; if (desc->vlan_id && desc->vlan_id != f->key.vlan_id) return false; if (desc->port_ifindex && desc->port_ifindex != port_ifidx) return false; if (desc->flags_mask && (f->flags & desc->flags_mask) != desc->flags) return false; return true; } /* Flush forwarding database entries matching the description */ void br_fdb_flush(struct net_bridge *br, const struct net_bridge_fdb_flush_desc *desc) { struct net_bridge_fdb_entry *f; rcu_read_lock(); hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) { if (!__fdb_flush_matches(br, f, desc)) continue; 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(); } static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state) { unsigned long flags = 0; if (ndm_state & NUD_PERMANENT) __set_bit(BR_FDB_LOCAL, &flags); if (ndm_state & NUD_NOARP) __set_bit(BR_FDB_STATIC, &flags); return flags; } static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags) { unsigned long flags = 0; if (ndm_flags & NTF_USE) __set_bit(BR_FDB_ADDED_BY_USER, &flags); if (ndm_flags & NTF_EXT_LEARNED) __set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags); if (ndm_flags & NTF_OFFLOADED) __set_bit(BR_FDB_OFFLOADED, &flags); if (ndm_flags & NTF_STICKY) __set_bit(BR_FDB_STICKY, &flags); return flags; } static int __fdb_flush_validate_ifindex(const struct net_bridge *br, int ifindex, struct netlink_ext_ack *extack) { const struct net_device *dev; dev = __dev_get_by_index(dev_net(br->dev), ifindex); if (!dev) { NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex"); return -ENODEV; } if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) { NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge port"); return -EINVAL; } if (netif_is_bridge_master(dev) && dev != br->dev) { NL_SET_ERR_MSG_MOD(extack, "Flush bridge device does not match target bridge device"); return -EINVAL; } if (netif_is_bridge_port(dev)) { struct net_bridge_port *p = br_port_get_rtnl(dev); if (p->br != br) { NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device"); return -EINVAL; } } return 0; } int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[], struct net_device *dev, u16 vid, struct netlink_ext_ack *extack) { u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS; struct net_bridge_fdb_flush_desc desc = { .vlan_id = vid }; struct net_bridge_port *p = NULL; struct net_bridge *br; if (netif_is_bridge_master(dev)) { br = netdev_priv(dev); } else { p = br_port_get_rtnl(dev); if (!p) { NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge port"); return -EINVAL; } br = p->br; } if (ndm_flags & ~FDB_FLUSH_ALLOWED_NDM_FLAGS) { NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm flag bits set"); return -EINVAL; } if (ndm->ndm_state & ~FDB_FLUSH_ALLOWED_NDM_STATES) { NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm state bits set"); return -EINVAL; } desc.flags |= __ndm_state_to_fdb_flags(ndm->ndm_state); desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags); if (tb[NDA_NDM_STATE_MASK]) { u16 ndm_state_mask = nla_get_u16(tb[NDA_NDM_STATE_MASK]); desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask); } if (tb[NDA_NDM_FLAGS_MASK]) { u8 ndm_flags_mask = nla_get_u8(tb[NDA_NDM_FLAGS_MASK]); desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask); } if (tb[NDA_IFINDEX]) { int err, ifidx = nla_get_s32(tb[NDA_IFINDEX]); err = __fdb_flush_validate_ifindex(br, ifidx, extack); if (err) return err; desc.port_ifindex = ifidx; } else if (p) { /* flush was invoked with port device and NTF_MASTER */ desc.port_ifindex = p->dev->ifindex; } br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n", desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask); br_fdb_flush(br, &desc); return 0; } /* 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 { const struct net_bridge_port *dst = NULL; fdb = br_fdb_find_rcu(port->br, addr, 0); if (fdb) dst = READ_ONCE(fdb->dst); ret = dst && dst->dev != dev && 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; } /* Add entry for local address of interface */ int br_fdb_add_local(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_add_local(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 != READ_ONCE(fdb->dst) && !test_bit(BR_FDB_STICKY, &fdb->flags))) { br_switchdev_fdb_notify(br, fdb, RTM_DELNEIGH); WRITE_ONCE(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); } } /* 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 (!netif_is_bridge_master(dev)) 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 (READ_ONCE(fdb->dst) != source) { WRITE_ONCE(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 (netif_is_bridge_master(dev)) { 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 || READ_ONCE(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 netlink_ext_ack *extack) { struct net_bridge_vlan_group *vg; struct net_bridge_port *p = NULL; struct net_bridge_vlan *v; struct net_bridge *br; int err; if (netif_is_bridge_master(dev)) { 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 (READ_ONCE(fdb->dst) != p) { WRITE_ONCE(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);