Hello,
On Wed, 2019-02-13 at 20:46 +0100, Eric Leblond wrote:
> Hello,
>
> I've got a simple socket filter program that seems to interrupt when
> calling the load_word construct. I'm seeing the first message but
> never
> the second one.
>
> The code is the following
>
> int SEC("filter") hashfilter(struct __sk_buff *skb) {
> __u32 nhoff = BPF_LL_OFF + ETH_HLEN;
So it seems the problem was coming from this line. Removing BPF_LL_OFF
fixes the problem for kernel starting 4.18.
Is this a known issue ?
Is there something that would allow a BPF file to work independently of
the kernel version ?
> __u32 ip = 0;
> __u32 *value = NULL;
> #if 1
> char fmtrei[] = "word load\n";
> bpf_trace_printk(fmtrei, sizeof(fmtrei));
> #endif
> ip = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
> #if 1
> char fmti[] = "work done\n";
> bpf_trace_printk(fmti, sizeof(fmti));
> #endif
> In 4.18 and above this is not working but older kernel were ok.
>
> Any suggestion will be appreciated.
>
> Best regards,
BR,
--
Eric Leblond <eric@xxxxxxxxx>
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