iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

neighbor: Remove externally learned entries from gc_list

Browse Source 
Externally learned entries are similar to PERMANENT entries in the
sense they are managed by userspace and can not be garbage collected.
As such remove them from the gc_list, remove the flags check from
neigh_forced_gc and skip threshold checks in neigh_alloc. As with
PERMANENT entries, this allows unlimited number of NTF_EXT_LEARNED
entries.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2018-12-11 18:57:25 -07:00 committed by David S. Miller
parent 526f1b587c
commit e997f8a20a
1 changed files with 28 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
net/core/neighbour.c
View File

@ -129,21 +129,22 @@ static void neigh_mark_dead(struct neighbour *n)
static void neigh_update_gc_list(struct neighbour *n)
{
bool on_gc_list, new_is_perm;
bool on_gc_list, exempt_from_gc;
write_lock_bh(&n->tbl->lock);
write_lock(&n->lock);
/* remove from the gc list if new state is permanent;
* add to the gc list if new state is not permanent
/* remove from the gc list if new state is permanent or if neighbor
* is externally learned; otherwise entry should be on the gc list
*/
new_is_perm = n->nud_state & NUD_PERMANENT;
exempt_from_gc = n->nud_state & NUD_PERMANENT ||
n->flags & NTF_EXT_LEARNED;
on_gc_list = !list_empty(&n->gc_list);
if (new_is_perm && on_gc_list) {
if (exempt_from_gc && on_gc_list) {
list_del_init(&n->gc_list);
atomic_dec(&n->tbl->gc_entries);
} else if (!new_is_perm && !on_gc_list) {
} else if (!exempt_from_gc && !on_gc_list) {
/* add entries to the tail; cleaning removes from the front */
list_add_tail(&n->gc_list, &n->tbl->gc_list);
atomic_inc(&n->tbl->gc_entries);
@ -153,13 +154,14 @@ static void neigh_update_gc_list(struct neighbour *n)
write_unlock_bh(&n->tbl->lock);
}
static void neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
static bool neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
int *notify)
{
bool rc = false;
u8 ndm_flags;
if (!(flags & NEIGH_UPDATE_F_ADMIN))
return;
return rc;
ndm_flags = (flags & NEIGH_UPDATE_F_EXT_LEARNED) ? NTF_EXT_LEARNED : 0;
if ((neigh->flags ^ ndm_flags) & NTF_EXT_LEARNED) {
@ -167,8 +169,11 @@ static void neigh_update_ext_learned(struct neighbour *neigh, u32 flags,
neigh->flags |= NTF_EXT_LEARNED;
else
neigh->flags &= ~NTF_EXT_LEARNED;
rc = true;
*notify = 1;
}
return rc;
}
static bool neigh_del(struct neighbour *n, struct neighbour __rcu **np,
@ -219,7 +224,6 @@ static int neigh_forced_gc(struct neigh_table *tbl)
{
int max_clean = atomic_read(&tbl->gc_entries) - tbl->gc_thresh2;
unsigned long tref = jiffies - 5 * HZ;
u8 flags = NTF_EXT_LEARNED;
struct neighbour *n, *tmp;
int shrunk = 0;
@ -233,7 +237,7 @@ static int neigh_forced_gc(struct neigh_table *tbl)
write_lock(&n->lock);
if ((n->nud_state == NUD_FAILED) ||
(!(n->flags & flags) && time_after(tref, n->updated)))
time_after(tref, n->updated))
remove = true;
write_unlock(&n->lock);
@ -371,13 +375,13 @@ EXPORT_SYMBOL(neigh_ifdown);
static struct neighbour *neigh_alloc(struct neigh_table *tbl,
struct net_device *dev,
bool permanent)
bool exempt_from_gc)
{
struct neighbour *n = NULL;
unsigned long now = jiffies;
int entries;
if (permanent)
if (exempt_from_gc)
goto do_alloc;
entries = atomic_inc_return(&tbl->gc_entries) - 1;
@ -419,7 +423,7 @@ out:
return n;
out_entries:
if (!permanent)
if (!exempt_from_gc)
atomic_dec(&tbl->gc_entries);
goto out;
}
@ -566,9 +570,9 @@ EXPORT_SYMBOL(neigh_lookup_nodev);
static struct neighbour *___neigh_create(struct neigh_table *tbl,
const void *pkey,
struct net_device *dev,
bool permanent, bool want_ref)
bool exempt_from_gc, bool want_ref)
{
struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev, permanent);
struct neighbour *n1, *rc, *n = neigh_alloc(tbl, dev, exempt_from_gc);
u32 hash_val;
unsigned int key_len = tbl->key_len;
int error;
@ -634,7 +638,7 @@ static struct neighbour *___neigh_create(struct neigh_table *tbl,
}
n->dead = 0;
if (!permanent)
if (!exempt_from_gc)
list_add_tail(&n->gc_list, &n->tbl->gc_list);
if (want_ref)
@ -1210,6 +1214,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr,
u8 new, u32 flags, u32 nlmsg_pid,
struct netlink_ext_ack *extack)
{
bool ext_learn_change = false;
u8 old;
int err;
int notify = 0;
@ -1230,7 +1235,7 @@ static int __neigh_update(struct neighbour *neigh, const u8 *lladdr,
goto out;
}
neigh_update_ext_learned(neigh, flags, &notify);
ext_learn_change = neigh_update_ext_learned(neigh, flags, &notify);
if (!(new & NUD_VALID)) {
neigh_del_timer(neigh);
@ -1376,7 +1381,7 @@ out:
neigh_update_is_router(neigh, flags, &notify);
write_unlock_bh(&neigh->lock);
if ((new ^ old) & NUD_PERMANENT)
if (((new ^ old) & NUD_PERMANENT) || ext_learn_change)
neigh_update_gc_list(neigh);
if (notify)
@ -1881,14 +1886,16 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh,
neigh = neigh_lookup(tbl, dst, dev);
if (neigh == NULL) {
bool exempt_from_gc;
if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
err = -ENOENT;
goto out;
}
neigh = ___neigh_create(tbl, dst, dev,
ndm->ndm_state & NUD_PERMANENT,
true);
exempt_from_gc = ndm->ndm_state & NUD_PERMANENT ||
ndm->ndm_flags & NTF_EXT_LEARNED;
neigh = ___neigh_create(tbl, dst, dev, exempt_from_gc, true);
if (IS_ERR(neigh)) {
err = PTR_ERR(neigh);
goto out;