Re: [PATCH] selftests_bpf: extend test_tc_tunnel test with vxlan

[Willem de Bruijn]

On Thu, Mar 4, 2021 at 1:42 AM Xuesen Huang <hxseverything@xxxxxxxxx> wrote:
>
> From: Xuesen Huang <huangxuesen@xxxxxxxxxxxx>
>
> Add BPF_F_ADJ_ROOM_ENCAP_L2_ETH flag to the existing tests which
> encapsulates the ethernet as the inner l2 header.
>
> Update a vxlan encapsulation test case.
>
> Signed-off-by: Xuesen Huang <huangxuesen@xxxxxxxxxxxx>
> Signed-off-by: Li Wang <wangli09@xxxxxxxxxxxx>
> Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>

Please mark patch target: [PATCH bpf-next]

> ---
>  tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 113 ++++++++++++++++++---
>  tools/testing/selftests/bpf/test_tc_tunnel.sh      |  15 ++-
>  2 files changed, 111 insertions(+), 17 deletions(-)


> -static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto,
> -                                     __u16 l2_proto)
> +static __always_inline int __encap_ipv4(struct __sk_buff *skb, __u8 encap_proto,
> +                                       __u16 l2_proto, __u16 ext_proto)
>  {
>         __u16 udp_dst = UDP_PORT;
>         struct iphdr iph_inner;
>         struct v4hdr h_outer;
>         struct tcphdr tcph;
>         int olen, l2_len;
> +       __u8 *l2_hdr = NULL;
>         int tcp_off;
>         __u64 flags;
>
> @@ -141,7 +157,11 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto,
>                 break;
>         case ETH_P_TEB:
>                 l2_len = ETH_HLEN;
> -               udp_dst = ETH_OVER_UDP_PORT;
> +               if (ext_proto & EXTPROTO_VXLAN) {
> +                       udp_dst = VXLAN_UDP_PORT;
> +                       l2_len += sizeof(struct vxlanhdr);
> +               } else
> +                       udp_dst = ETH_OVER_UDP_PORT;
>                 break;
>         }
>         flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len);
> @@ -171,14 +191,26 @@ static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto,
>         }
>
>         /* add L2 encap (if specified) */
> +       l2_hdr = (__u8 *)&h_outer + olen;
>         switch (l2_proto) {
>         case ETH_P_MPLS_UC:
> -               *((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label;
> +               *(__u32 *)l2_hdr = mpls_label;
>                 break;
>         case ETH_P_TEB:
> -               if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen,
> -                                      ETH_HLEN))
> +               flags |= BPF_F_ADJ_ROOM_ENCAP_L2_ETH;
> +
> +               if (ext_proto & EXTPROTO_VXLAN) {
> +                       struct vxlanhdr *vxlan_hdr = (struct vxlanhdr *)l2_hdr;
> +
> +                       vxlan_hdr->vx_flags = VXLAN_FLAGS;
> +                       vxlan_hdr->vx_vni = bpf_htonl((VXLAN_VNI & VXLAN_VNI_MASK) << 8);
> +
> +                       l2_hdr += sizeof(struct vxlanhdr);

should this be l2_len? (here and ipv6 below)

> +SEC("encap_vxlan_eth")
> +int __encap_vxlan_eth(struct __sk_buff *skb)
> +{
> +       if (skb->protocol == __bpf_constant_htons(ETH_P_IP))
> +               return __encap_ipv4(skb, IPPROTO_UDP,
> +                               ETH_P_TEB,
> +                               EXTPROTO_VXLAN);

non-standard indentation: align with the opening parenthesis. (here
and ipv6 below)