On Wed, May 22, 2024 at 07:57:10AM -0700, Vadim Fedorenko wrote:
> Add special flag to validate that TC BPF program properly updates
> checksum information in skb.
>
> Signed-off-by: Vadim Fedorenko <vadfed@xxxxxxxx>
...
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index f6aad4ed2ab2..841552785c65 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -974,10 +974,13 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> int hh_len = ETH_HLEN;
> struct sk_buff *skb;
> struct sock *sk;
> + __wsum csum;
> + __sum16 sum;
Hi Vadim,
sum seems to be is unused in this function.
And, fwiiw, the scope of csum looks like it could be reduced.
> void *data;
> int ret;
>
> - if (kattr->test.flags || kattr->test.cpu || kattr->test.batch_size)
> + if ((kattr->test.flags & ~BPF_F_TEST_SKB_CHECKSUM_COMPLETE) ||
> + kattr->test.cpu || kattr->test.batch_size)
> return -EINVAL;
>
> data = bpf_test_init(kattr, kattr->test.data_size_in,
> @@ -1025,6 +1028,12 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
>
> skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
> __skb_put(skb, size);
> +
> + if (kattr->test.flags & BPF_F_TEST_SKB_CHECKSUM_COMPLETE) {
> + skb->csum = skb_checksum(skb, 0, skb->len, 0);
> + skb->ip_summed = CHECKSUM_COMPLETE;
> + }
> +
> if (ctx && ctx->ifindex > 1) {
> dev = dev_get_by_index(net, ctx->ifindex);
> if (!dev) {
> @@ -1079,6 +1088,14 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
> }
> convert_skb_to___skb(skb, ctx);
>
> + if (kattr->test.flags & BPF_F_TEST_SKB_CHECKSUM_COMPLETE) {
> + csum = skb_checksum(skb, 0, skb->len, 0);
> + if (skb->csum != csum) {
> + ret = -EINVAL;
> + goto out;
> + }
> + }
> +
> size = skb->len;
> /* bpf program can never convert linear skb to non-linear */
> if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
...
