neighbour: make proxy_queue.qlen limit per-device

Right now we have a neigh_param PROXY_QLEN which specifies maximum length
of neigh_table->proxy_queue. But in fact, this limitation doesn't work well
because check condition looks like:
tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)

The problem is that p (struct neigh_parms) is a per-device thing,
but tbl (struct neigh_table) is a system-wide global thing.

It seems reasonable to make proxy_queue limit per-device based.

v2:
	- nothing changed in this patch
v3:
	- rebase to net tree

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@kernel.org>
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Cc: Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: kernel@openvz.org
Cc: devel@openvz.org
Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 9f0bab0589d9c3e6a87d7de6365dbdb4bbd7af0b..3827a6b395fdb67f391853d528bb6f7ff9169449 100644 (file)
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -83,6 +83,7 @@ struct neigh_parms {
        struct rcu_head rcu_head;
 
        int     reachable_time;
+       int     qlen;
        int     data[NEIGH_VAR_DATA_MAX];
        DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX);
 };

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 0e38a05d5b23320e3fd1ff6219364c1a8081a0f5..5b669eb802708e6a4c735d57370fa65b77d16a7a 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -316,9 +316,18 @@ static void pneigh_queue_purge(struct sk_buff_head *list, struct net *net)
        skb = skb_peek(list);
        while (skb != NULL) {
                struct sk_buff *skb_next = skb_peek_next(skb, list);
-               if (net == NULL || net_eq(dev_net(skb->dev), net)) {
+               struct net_device *dev = skb->dev;
+               if (net == NULL || net_eq(dev_net(dev), net)) {
+                       struct in_device *in_dev;
+
+                       rcu_read_lock();
+                       in_dev = __in_dev_get_rcu(dev);
+                       if (in_dev)
+                               in_dev->arp_parms->qlen--;
+                       rcu_read_unlock();
                        __skb_unlink(skb, list);
-                       dev_put(skb->dev);
+
+                       dev_put(dev);
                        kfree_skb(skb);
                }
                skb = skb_next;
@@ -1606,8 +1615,15 @@ static void neigh_proxy_process(struct timer_list *t)
 
                if (tdif <= 0) {
                        struct net_device *dev = skb->dev;
+                       struct in_device *in_dev;
 
+                       rcu_read_lock();
+                       in_dev = __in_dev_get_rcu(dev);
+                       if (in_dev)
+                               in_dev->arp_parms->qlen--;
+                       rcu_read_unlock();
                        __skb_unlink(skb, &tbl->proxy_queue);
+
                        if (tbl->proxy_redo && netif_running(dev)) {
                                rcu_read_lock();
                                tbl->proxy_redo(skb);
@@ -1632,7 +1648,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
        unsigned long sched_next = jiffies +
                        prandom_u32_max(NEIGH_VAR(p, PROXY_DELAY));
 
-       if (tbl->proxy_queue.qlen > NEIGH_VAR(p, PROXY_QLEN)) {
+       if (p->qlen > NEIGH_VAR(p, PROXY_QLEN)) {
                kfree_skb(skb);
                return;
        }
@@ -1648,6 +1664,7 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
        skb_dst_drop(skb);
        dev_hold(skb->dev);
        __skb_queue_tail(&tbl->proxy_queue, skb);
+       p->qlen++;
        mod_timer(&tbl->proxy_timer, sched_next);
        spin_unlock(&tbl->proxy_queue.lock);
 }
@@ -1680,6 +1697,7 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev,
                refcount_set(&p->refcnt, 1);
                p->reachable_time =
                                neigh_rand_reach_time(NEIGH_VAR(p, BASE_REACHABLE_TIME));
+               p->qlen = 0;
                netdev_hold(dev, &p->dev_tracker, GFP_KERNEL);
                p->dev = dev;
                write_pnet(&p->net, net);
@@ -1745,6 +1763,7 @@ void neigh_table_init(int index, struct neigh_table *tbl)
        refcount_set(&tbl->parms.refcnt, 1);
        tbl->parms.reachable_time =
                          neigh_rand_reach_time(NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME));
+       tbl->parms.qlen = 0;
 
        tbl->stats = alloc_percpu(struct neigh_statistics);
        if (!tbl->stats)