On Tue, Jul 26, 2022 at 11:48 AM Joanne Koong <joannelkoong@xxxxxxxxx> wrote:
>
>
> -static __always_inline int handle_ipv4(struct xdp_md *xdp)
> +static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xdp_ptr)
> {
> - void *data_end = (void *)(long)xdp->data_end;
> - void *data = (void *)(long)xdp->data;
> + struct bpf_dynptr new_xdp_ptr;
> struct iptnl_info *tnl;
> struct ethhdr *new_eth;
> struct ethhdr *old_eth;
> - struct iphdr *iph = data + sizeof(struct ethhdr);
> + struct iphdr *iph;
> __u16 *next_iph;
> __u16 payload_len;
> struct vip vip = {};
> @@ -90,10 +90,12 @@ static __always_inline int handle_ipv4(struct xdp_md *xdp)
> __u32 csum = 0;
> int i;
>
> - if (iph + 1 > data_end)
> + iph = bpf_dynptr_data(xdp_ptr, ethhdr_sz,
> + iphdr_sz + (tcphdr_sz > udphdr_sz ? tcphdr_sz : udphdr_sz));
> + if (!iph)
> return XDP_DROP;
dynptr based xdp/skb access looks neat.
Maybe in addition to bpf_dynptr_data() we can add helper(s)
that return skb/xdp_md from dynptr?
This way the code will be passing dynptr only and there will
be no need to pass around 'struct xdp_md *xdp' (like this function).
Separately please keep the existing tests instead of converting them.
Either ifdef data/data_end vs dynptr style or copy paste
the whole test into a new .c file. Whichever is cleaner.
