From 9aa1206e8f48222f35a0c809f33b2f4aaa1e2661 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Sun, 11 Oct 2020 01:40:02 +0200 Subject: bpf: Add redirect_peer helper Add an efficient ingress to ingress netns switch that can be used out of tc BPF programs in order to redirect traffic from host ns ingress into a container veth device ingress without having to go via CPU backlog queue [0]. For local containers this can also be utilized and path via CPU backlog queue only needs to be taken once, not twice. On a high level this borrows from ipvlan which does similar switch in __netif_receive_skb_core() and then iterates via another_round. This helps to reduce latency for mentioned use cases. Pod to remote pod with redirect(), TCP_RR [1]: # percpu_netperf 10.217.1.33 RT_LATENCY: 122.450 (per CPU: 122.666 122.401 122.333 122.401 ) MEAN_LATENCY: 121.210 (per CPU: 121.100 121.260 121.320 121.160 ) STDDEV_LATENCY: 120.040 (per CPU: 119.420 119.910 125.460 115.370 ) MIN_LATENCY: 46.500 (per CPU: 47.000 47.000 47.000 45.000 ) P50_LATENCY: 118.500 (per CPU: 118.000 119.000 118.000 119.000 ) P90_LATENCY: 127.500 (per CPU: 127.000 128.000 127.000 128.000 ) P99_LATENCY: 130.750 (per CPU: 131.000 131.000 129.000 132.000 ) TRANSACTION_RATE: 32666.400 (per CPU: 8152.200 8169.842 8174.439 8169.897 ) Pod to remote pod with redirect_peer(), TCP_RR: # percpu_netperf 10.217.1.33 RT_LATENCY: 44.449 (per CPU: 43.767 43.127 45.279 45.622 ) MEAN_LATENCY: 45.065 (per CPU: 44.030 45.530 45.190 45.510 ) STDDEV_LATENCY: 84.823 (per CPU: 66.770 97.290 84.380 90.850 ) MIN_LATENCY: 33.500 (per CPU: 33.000 33.000 34.000 34.000 ) P50_LATENCY: 43.250 (per CPU: 43.000 43.000 43.000 44.000 ) P90_LATENCY: 46.750 (per CPU: 46.000 47.000 47.000 47.000 ) P99_LATENCY: 52.750 (per CPU: 51.000 54.000 53.000 53.000 ) TRANSACTION_RATE: 90039.500 (per CPU: 22848.186 23187.089 22085.077 21919.130 ) [0] https://linuxplumbersconf.org/event/7/contributions/674/attachments/568/1002/plumbers_2020_cilium_load_balancer.pdf [1] https://github.com/borkmann/netperf_scripts/blob/master/percpu_netperf Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201010234006.7075-3-daniel@iogearbox.net --- net/core/filter.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 47 insertions(+), 7 deletions(-) (limited to 'net/core/filter.c') diff --git a/net/core/filter.c b/net/core/filter.c index 5da44b11e1ec..fab951c6be57 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2380,8 +2380,9 @@ out: /* Internal, non-exposed redirect flags. */ enum { - BPF_F_NEIGH = (1ULL << 1), -#define BPF_F_REDIRECT_INTERNAL (BPF_F_NEIGH) + BPF_F_NEIGH = (1ULL << 1), + BPF_F_PEER = (1ULL << 2), +#define BPF_F_REDIRECT_INTERNAL (BPF_F_NEIGH | BPF_F_PEER) }; BPF_CALL_3(bpf_clone_redirect, struct sk_buff *, skb, u32, ifindex, u64, flags) @@ -2430,19 +2431,35 @@ EXPORT_PER_CPU_SYMBOL_GPL(bpf_redirect_info); int skb_do_redirect(struct sk_buff *skb) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + struct net *net = dev_net(skb->dev); struct net_device *dev; u32 flags = ri->flags; - dev = dev_get_by_index_rcu(dev_net(skb->dev), ri->tgt_index); + dev = dev_get_by_index_rcu(net, ri->tgt_index); ri->tgt_index = 0; - if (unlikely(!dev)) { - kfree_skb(skb); - return -EINVAL; + ri->flags = 0; + if (unlikely(!dev)) + goto out_drop; + if (flags & BPF_F_PEER) { + const struct net_device_ops *ops = dev->netdev_ops; + + if (unlikely(!ops->ndo_get_peer_dev || + !skb_at_tc_ingress(skb))) + goto out_drop; + dev = ops->ndo_get_peer_dev(dev); + if (unlikely(!dev || + !is_skb_forwardable(dev, skb) || + net_eq(net, dev_net(dev)))) + goto out_drop; + skb->dev = dev; + return -EAGAIN; } - return flags & BPF_F_NEIGH ? __bpf_redirect_neigh(skb, dev) : __bpf_redirect(skb, dev, flags); +out_drop: + kfree_skb(skb); + return -EINVAL; } BPF_CALL_2(bpf_redirect, u32, ifindex, u64, flags) @@ -2466,6 +2483,27 @@ static const struct bpf_func_proto bpf_redirect_proto = { .arg2_type = ARG_ANYTHING, }; +BPF_CALL_2(bpf_redirect_peer, u32, ifindex, u64, flags) +{ + struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + + if (unlikely(flags)) + return TC_ACT_SHOT; + + ri->flags = BPF_F_PEER; + ri->tgt_index = ifindex; + + return TC_ACT_REDIRECT; +} + +static const struct bpf_func_proto bpf_redirect_peer_proto = { + .func = bpf_redirect_peer, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, + .arg2_type = ARG_ANYTHING, +}; + BPF_CALL_2(bpf_redirect_neigh, u32, ifindex, u64, flags) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); @@ -7053,6 +7091,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_redirect_proto; case BPF_FUNC_redirect_neigh: return &bpf_redirect_neigh_proto; + case BPF_FUNC_redirect_peer: + return &bpf_redirect_peer_proto; case BPF_FUNC_get_route_realm: return &bpf_get_route_realm_proto; case BPF_FUNC_get_hash_recalc: -- cgit v1.2.3