6.18-stable review patch. If anyone has any objections, please let me know.
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From: Jianbo Liu jianbol@nvidia.com
[ Upstream commit 9ab89bde13e5251e1d0507e1cc426edcdfe19142 ]
When initializing the MAC addresses for an outbound IPsec packet offload rule in mlx5e_ipsec_init_macs, the call to dst_neigh_lookup is used to find the next-hop neighbor (typically the gateway in tunnel mode). This call might create a new neighbor entry if one doesn't already exist. This newly created entry starts in the INCOMPLETE state, as the kernel hasn't yet sent an ARP or NDISC probe to resolve the MAC address. In this case, neigh_ha_snapshot will correctly return an all-zero MAC address.
IPsec packet offload requires the actual next-hop MAC address to program the rule correctly. If the neighbor state is INCOMPLETE when the rule is created, the hardware rule is programmed with an all-zero destination MAC address. Packets sent using this rule will be subsequently dropped by the receiving network infrastructure or host.
This patch adds a check specifically for the outbound offload path. If neigh_ha_snapshot returns an all-zero MAC address, it proactively calls neigh_event_send(n, NULL). This ensures the kernel immediately sends the initial ARP or NDISC probe if one isn't already pending, accelerating the resolution process. This helps prevent the hardware rule from being programmed with an invalid MAC address and avoids packet drops due to unresolved neighbors.
Fixes: 71670f766b8f ("net/mlx5e: Support routed networks during IPsec MACs initialization") Signed-off-by: Jianbo Liu jianbol@nvidia.com Reviewed-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Link: https://patch.msgid.link/1765284977-1363052-8-git-send-email-tariqt@nvidia.c... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c index 6c79b9cea2efb..a8fb4bec369cf 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c @@ -358,6 +358,9 @@ static void mlx5e_ipsec_init_macs(struct mlx5e_ipsec_sa_entry *sa_entry,
neigh_ha_snapshot(addr, n, netdev); ether_addr_copy(dst, addr); + if (attrs->dir == XFRM_DEV_OFFLOAD_OUT && + is_zero_ether_addr(addr)) + neigh_event_send(n, NULL); dst_release(rt_dst_entry); neigh_release(n); return;