From: Peilin Ye peilin.ye@bytedance.com
[ Upstream commit 024ee930cb3c9ae49e4266aee89cfde0ebb407e1 ]
Traffic redirected by bpf_redirect_peer() (used by recent CNIs like Cilium) is not accounted for in the RX stats of supported devices (that is, veth and netkit), confusing user space metrics collectors such as cAdvisor [0], as reported by Youlun.
Fix it by calling dev_sw_netstats_rx_add() in skb_do_redirect(), to update RX traffic counters. Devices that support ndo_get_peer_dev _must_ use the @tstats per-CPU counters (instead of @lstats, or @dstats).
To make this more fool-proof, error out when ndo_get_peer_dev is set but @tstats are not selected.
[0] Specifically, the "container_network_receive_{byte,packet}s_total" counters are affected.
Fixes: 9aa1206e8f48 ("bpf: Add redirect_peer helper") Reported-by: Youlun Zhang zhangyoulun@bytedance.com Signed-off-by: Peilin Ye peilin.ye@bytedance.com Co-developed-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Nikolay Aleksandrov razor@blackwall.org Link: https://lore.kernel.org/r/20231114004220.6495-6-daniel@iogearbox.net Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net --- net/core/dev.c | 8 ++++++++ net/core/filter.c | 1 + 2 files changed, 9 insertions(+)
diff --git a/net/core/dev.c b/net/core/dev.c index 5151f69dd724..2ee1a535b3cb 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9995,6 +9995,14 @@ static int netdev_do_alloc_pcpu_stats(struct net_device *dev) { void __percpu *v;
+ /* Drivers implementing ndo_get_peer_dev must support tstat + * accounting, so that skb_do_redirect() can bump the dev's + * RX stats upon network namespace switch. + */ + if (dev->netdev_ops->ndo_get_peer_dev && + dev->pcpu_stat_type != NETDEV_PCPU_STAT_TSTATS) + return -EOPNOTSUPP; + switch (dev->pcpu_stat_type) { case NETDEV_PCPU_STAT_NONE: return 0; diff --git a/net/core/filter.c b/net/core/filter.c index 2f6fef5f5864..e766e66ef62a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2491,6 +2491,7 @@ int skb_do_redirect(struct sk_buff *skb) net_eq(net, dev_net(dev)))) goto out_drop; skb->dev = dev; + dev_sw_netstats_rx_add(dev, skb->len); return -EAGAIN; } return flags & BPF_F_NEIGH ?