2020-04-20 18:36:20

by Maciej Żenczykowski

Subject: [PATCH] net: bpf: Allow TC programs to call BPF_FUNC_skb_change_head

From: Lorenzo Colitti <[email protected]>

This allows TC eBPF programs to modify and forward (redirect) packets
from interfaces without ethernet headers (for example cellular)
to interfaces with (for example ethernet/wifi).

The lack of this appears to simply be an oversight.

Tested:
in active use in Android R on 4.14+ devices for ipv6
cellular to wifi tethering offload.

Signed-off-by: Lorenzo Colitti <[email protected]>
Signed-off-by: Maciej Żenczykowski <[email protected]>
---
net/core/filter.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 7d6ceaa54d21..755867867e57 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6213,6 +6213,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_skb_adjust_room_proto;
case BPF_FUNC_skb_change_tail:
return &bpf_skb_change_tail_proto;
+ case BPF_FUNC_skb_change_head:
+ return &bpf_skb_change_head_proto;
case BPF_FUNC_skb_get_tunnel_key:
return &bpf_skb_get_tunnel_key_proto;
case BPF_FUNC_skb_set_tunnel_key:
--
2.26.1.301.g55bc3eb7cb9-goog

2020-04-26 16:06:11

by Alexei Starovoitov

Subject: Re: [PATCH] net: bpf: Allow TC programs to call BPF_FUNC_skb_change_head

On Mon, Apr 20, 2020 at 11:34 AM Maciej Żenczykowski
<[email protected]> wrote:
>
> From: Lorenzo Colitti <[email protected]>
>
> This allows TC eBPF programs to modify and forward (redirect) packets
> from interfaces without ethernet headers (for example cellular)
> to interfaces with (for example ethernet/wifi).
>
> The lack of this appears to simply be an oversight.
>
> Tested:
> in active use in Android R on 4.14+ devices for ipv6
> cellular to wifi tethering offload.
>
> Signed-off-by: Lorenzo Colitti <[email protected]>
> Signed-off-by: Maciej Żenczykowski <[email protected]>

Applied. Thanks