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authorZheng Li <James.Z.Li@Dell.com>2024-04-16 17:53:43 +0800
committerPaolo Abeni <pabeni@redhat.com>2024-04-18 12:01:03 +0200
commiteabf425bc6ad32fa49cfb35c7bc59db07dfdd36e (patch)
tree2073a24b0ea57c70dfe2632938a70fca27a91743
parentba3de6d8035ef1efdd27e9a5047412f7cf3fb3a6 (diff)
downloadmptcp_net-next-eabf425bc6ad32fa49cfb35c7bc59db07dfdd36e.tar.gz
neighbour: guarantee the localhost connections be established successfully even the ARP table is full
Inter-process communication on localhost should be established successfully even the ARP table is full, many processes on server machine use the localhost to communicate such as command-line interface (CLI), servers hope all CLI commands can be executed successfully even the arp table is full. Right now CLI commands got timeout when the arp table is full. Set the parameter of exempt_from_gc to be true for LOOPBACK net device to keep localhost neigh in arp table, not removed by gc. the steps of reproduced: server with "gc_thresh3 = 1024" setting, ping server from more than 1024 same netmask Lan IPv4 addresses, run "ssh localhost" on console interface, then the command will get timeout. Signed-off-by: Zheng Li <James.Z.Li@Dell.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240416095343.540-1-lizheng043@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r--net/core/neighbour.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 552719c3bbc3d7..47d07b122f7abf 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -734,7 +734,9 @@ out_neigh_release:
struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
struct net_device *dev, bool want_ref)
{
- return ___neigh_create(tbl, pkey, dev, 0, false, want_ref);
+ bool exempt_from_gc = !!(dev->flags & IFF_LOOPBACK);
+
+ return ___neigh_create(tbl, pkey, dev, 0, exempt_from_gc, want_ref);
}
EXPORT_SYMBOL(__neigh_create);