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linux-zen-desktop/net/bridge/br_fdb.c

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Initial commit
2023-08-30 17:31:07 +02:00
// 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;
u32 ext_flags = 0;
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 (test_bit(BR_FDB_LOCKED, &fdb->flags))
ext_flags |= NTF_EXT_LOCKED;
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;
if (nla_put_u32(skb, NDA_FLAGS_EXT, ext_flags))
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(u32)) /* NDA_FLAGS_EXT */
+ 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);
/* Clear locked flag when roaming to an
* unlocked port.
*/
if (unlikely(test_bit(BR_FDB_LOCKED, &fdb->flags)))
clear_bit(BR_FDB_LOCKED, &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 (test_and_clear_bit(BR_FDB_LOCKED, &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, false, 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;
u32 ext_flags = 0;
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_FLAGS_EXT])
ext_flags = nla_get_u32(tb[NDA_FLAGS_EXT]);
if (ext_flags & NTF_EXT_LOCKED) {
NL_SET_ERR_MSG_MOD(extack, "Cannot add FDB entry with \"locked\" flag set");
return -EINVAL;
}
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 locked,
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);
if (locked && (!p || !(p->flags & BR_PORT_MAB)))
return -EINVAL;
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);
if (locked)
flags |= BIT(BR_FDB_LOCKED);
fdb = fdb_create(br, p, addr, vid, flags);
if (!fdb) {
err = -ENOMEM;
goto err_unlock;
}
fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
} else {
if (locked &&
(!test_bit(BR_FDB_LOCKED, &fdb->flags) ||
READ_ONCE(fdb->dst) != p)) {
err = -EINVAL;
goto err_unlock;
}
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 (locked != test_bit(BR_FDB_LOCKED, &fdb->flags)) {
change_bit(BR_FDB_LOCKED, &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);