From: David Ahern <dsahern@gmail.com>
To: Daniel Borkmann <daniel@iogearbox.net>, ast@kernel.org
Cc: john.fastabend@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH bpf-next 3/6] bpf: add redirect_neigh helper as redirect drop-in
Date: Thu, 24 Sep 2020 16:12:01 -0600 [thread overview]
Message-ID: <09aedc04-ee19-e72d-9a8d-aa4be7551a53@gmail.com> (raw)
In-Reply-To: <721fd3f8d5cf55169561e59fdec5fad2e0bf6115.1600967205.git.daniel@iogearbox.net>
On 9/24/20 12:21 PM, Daniel Borkmann wrote:
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 0f913755bcba..19caa2fc21e8 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -2160,6 +2160,205 @@ static int __bpf_redirect(struct sk_buff *skb, struct net_device *dev,
> return __bpf_redirect_no_mac(skb, dev, flags);
> }
>
> +#if IS_ENABLED(CONFIG_IPV6)
> +static int bpf_out_neigh_v6(struct net *net, struct sk_buff *skb)
> +{
> + struct dst_entry *dst = skb_dst(skb);
> + struct net_device *dev = dst->dev;
> + const struct in6_addr *nexthop;
> + struct neighbour *neigh;
> +
> + if (dev_xmit_recursion())
> + goto out_rec;
> + skb->dev = dev;
> + rcu_read_lock_bh();
> + nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
> + neigh = __ipv6_neigh_lookup_noref_stub(dev, nexthop);
> + if (unlikely(!neigh))
> + neigh = __neigh_create(ipv6_stub->nd_tbl, nexthop, dev, false);
the last 3 lines can be replaced with ip_neigh_gw6.
> + if (likely(!IS_ERR(neigh))) {
> + int ret;
> +
> + sock_confirm_neigh(skb, neigh);
> + dev_xmit_recursion_inc();
> + ret = neigh_output(neigh, skb, false);
> + dev_xmit_recursion_dec();
> + rcu_read_unlock_bh();
> + return ret;
> + }
> + rcu_read_unlock_bh();
> + IP6_INC_STATS(dev_net(dst->dev),
> + ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
> +out_drop:
> + kfree_skb(skb);
> + return -EINVAL;
> +out_rec:
> + net_crit_ratelimited("bpf: recursion limit reached on datapath, buggy bpf program?\n");
> + goto out_drop;
> +}
> +
...
> +
> +#if IS_ENABLED(CONFIG_INET)
> +static int bpf_out_neigh_v4(struct net *net, struct sk_buff *skb)
> +{
> + struct dst_entry *dst = skb_dst(skb);
> + struct rtable *rt = (struct rtable *)dst;
please use container_of here; I'd like to see the typecasts get removed.
> + struct net_device *dev = dst->dev;
> + u32 hh_len = LL_RESERVED_SPACE(dev);
> + struct neighbour *neigh;
> + bool is_v6gw = false;
> +
> + if (dev_xmit_recursion())
> + goto out_rec;
next prev parent reply other threads:[~2020-09-24 22:12 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-24 18:21 [PATCH bpf-next 0/6] Various BPF helper improvements Daniel Borkmann
2020-09-24 18:21 ` [PATCH bpf-next 1/6] bpf: add classid helper only based on skb->sk Daniel Borkmann
2020-09-25 14:46 ` Jakub Kicinski
2020-09-25 15:35 ` Daniel Borkmann
2020-09-24 18:21 ` [PATCH bpf-next 2/6] bpf, net: rework cookie generator as per-cpu one Daniel Borkmann
2020-09-24 18:58 ` Eric Dumazet
2020-09-24 22:03 ` Daniel Borkmann
2020-09-25 7:49 ` Eric Dumazet
2020-09-25 9:26 ` Daniel Borkmann
2020-09-25 15:00 ` Jakub Kicinski
2020-09-25 15:15 ` Eric Dumazet
2020-09-25 15:31 ` Jakub Kicinski
2020-09-25 15:45 ` Eric Dumazet
2020-09-24 18:21 ` [PATCH bpf-next 3/6] bpf: add redirect_neigh helper as redirect drop-in Daniel Borkmann
2020-09-24 22:12 ` David Ahern [this message]
2020-09-24 22:19 ` Daniel Borkmann
2020-09-24 18:21 ` [PATCH bpf-next 4/6] bpf, libbpf: add bpf_tail_call_static helper for bpf programs Daniel Borkmann
2020-09-24 20:53 ` Andrii Nakryiko
2020-09-24 22:17 ` Daniel Borkmann
2020-09-25 15:42 ` Daniel Borkmann
2020-09-25 15:52 ` Daniel Borkmann
2020-09-25 16:50 ` Andrii Nakryiko
2020-09-25 19:52 ` Daniel Borkmann
2020-09-25 6:13 ` Yonghong Song
2020-09-24 18:21 ` [PATCH bpf-next 5/6] bpf, selftests: use bpf_tail_call_static where appropriate Daniel Borkmann
2020-09-24 19:25 ` Maciej Fijalkowski
2020-09-24 22:03 ` Daniel Borkmann
2020-09-24 18:21 ` [PATCH bpf-next 6/6] bpf, selftests: add redirect_neigh selftest Daniel Borkmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=09aedc04-ee19-e72d-9a8d-aa4be7551a53@gmail.com \
--to=dsahern@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.