From: Daniel Borkmann <daniel@iogearbox•net>
To: Martin KaFai Lau <kafai@fb•com>, netdev@vger•kernel.org
Cc: Alexei Starovoitov <ast@fb•com>,
Brenden Blanco <bblanco@plumgrid•com>,
David Miller <davem@davemloft•net>,
Saeed Mahameed <saeedm@mellanox•com>,
Tariq Toukan <tariqt@mellanox•com>,
Kernel Team <kernel-team@fb•com>
Subject: Re: [PATCH net-next 1/4] bpf: xdp: Allow head adjustment in XDP prog
Date: Sat, 03 Dec 2016 01:22:05 +0100 [thread overview]
Message-ID: <5842102D.4000903@iogearbox.net> (raw)
In-Reply-To: <1480721013-1047541-2-git-send-email-kafai@fb.com>
On 12/03/2016 12:23 AM, Martin KaFai Lau wrote:
> This patch allows XDP prog to extend/remove the packet
> data at the head (like adding or removing header). It is
> done by adding a new XDP helper bpf_xdp_adjust_head().
>
> It also renames bpf_helper_changes_skb_data() to
> bpf_helper_changes_pkt_data() to better reflect
> that XDP prog does not work on skb.
>
> Signed-off-by: Martin KaFai Lau <kafai@fb•com>
[...]
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 56b43587d200..6902e2f73e38 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -2234,7 +2234,34 @@ static const struct bpf_func_proto bpf_skb_change_head_proto = {
> .arg3_type = ARG_ANYTHING,
> };
>
> -bool bpf_helper_changes_skb_data(void *func)
> +BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset)
> +{
> + /* Both mlx4 and mlx5 driver align each packet to PAGE_SIZE when
> + * XDP prog is set.
> + * If the above is not true for the other drivers to support
> + * bpf_xdp_adjust_head, struct xdp_buff can be extended.
> + */
> + void *head = (void *)((unsigned long)xdp->data & PAGE_MASK);
> + void *new_data = xdp->data + offset;
> +
> + if (new_data < head || new_data >= xdp->data_end)
> + /* The packet length must be >=1 */
Patch looks generally good to me. Should the min pkt len here be
limited to ETH_HLEN instead of 1?
> + return -EINVAL;
> +
> + xdp->data = new_data;
> +
> + return 0;
> +}
> +
> +static const struct bpf_func_proto bpf_xdp_adjust_head_proto = {
> + .func = bpf_xdp_adjust_head,
> + .gpl_only = false,
> + .ret_type = RET_INTEGER,
> + .arg1_type = ARG_PTR_TO_CTX,
> + .arg2_type = ARG_ANYTHING,
> +};
> +
> +bool bpf_helper_changes_pkt_data(void *func)
> {
> if (func == bpf_skb_vlan_push ||
> func == bpf_skb_vlan_pop ||
[...]
next prev parent reply other threads:[~2016-12-03 0:22 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 23:23 [PATCH net-next 0/4]: Allow head adjustment in XDP prog Martin KaFai Lau
2016-12-02 23:23 ` [PATCH net-next 1/4] bpf: xdp: " Martin KaFai Lau
2016-12-03 0:22 ` Daniel Borkmann [this message]
2016-12-03 3:43 ` Martin KaFai Lau
2016-12-03 15:24 ` Jesper Dangaard Brouer
2016-12-03 19:32 ` Martin KaFai Lau
2016-12-03 20:21 ` Daniel Borkmann
2016-12-02 23:23 ` [PATCH net-next 2/4] mlx4: xdp: Allow raising MTU up to one page minus eth and vlan hdrs Martin KaFai Lau
2016-12-03 0:07 ` Rick Jones
2016-12-04 3:19 ` Martin KaFai Lau
2016-12-05 17:46 ` Jakub Kicinski
2016-12-03 0:38 ` Eric Dumazet
2016-12-03 0:53 ` Alexei Starovoitov
2016-12-03 2:15 ` Eric Dumazet
2016-12-03 3:42 ` Martin KaFai Lau
2016-12-03 3:59 ` Eric Dumazet
2016-12-04 23:31 ` Saeed Mahameed
2016-12-05 0:52 ` Eric Dumazet
2016-12-02 23:23 ` [PATCH net-next 3/4] mlx4: xdp: Reserve headroom for receiving packet when XDP prog is active Martin KaFai Lau
2016-12-02 23:23 ` [PATCH net-next 4/4] bpf: xdp: Add XDP example for head adjustment Martin KaFai Lau
2016-12-03 15:17 ` [PATCH net-next 0/4]: Allow head adjustment in XDP prog Jesper Dangaard Brouer
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