Now i want to modify something of the skb with the ebpf in the prog_type kprobe. However, the help function `bpf_skb_store_bytes` is not supported with the prog_type BPF_PROG_TYPE_KPROBE. I test it

This is the problem: static inline uint16_t parse_tcp_pld(void *data, u64 nh_off, void *data_end) { uint16_t *pld = data + nh_off; if ((void*)&pld[1] > data_end) return 0; return

If I just copy your swapu16 function into my code (and it looks very similar to mine) the result continues to be the same (error). Here is a gist with python and c-components of my

Thank you! Let me run a gap analysis to see what’s different. -ilya Ilya Baldin Director, Networking Research and Infrastructure RENCI/UNC Chapel Hill http://www.renci.org

I’m staring at the BPF ‘pseudocode’ now. I wouldn’t put it past me to do something stupid. -ilya Ilya Baldin

Here is a full BCC version that worked for me: #!/usr/bin/env python import bcc text = """ static inline int swapu16(uint16_t *start, void *data_end, int off1, int off2) { int len =

Note that: R6=inv,min_value=4,max_value=65539,min_align=1,aux_off_align=2 "inv" means unknown value. Could you double check your program?

Thank you, everyone for the replies. This explains about bpf_probe_read. I tried the approach below (changed the check to offset +1) however that didn’t help, I still get the same error and BCC

<iovisor-dev@...> wrote: The error comes from here: https://github.com/iovisor/bcc/blob/master/src/cc/libbpf.c#L210 But as Yonghong said, you cannot use bpf_probe_read from XDP and

I was wondering about this last one, and where this suggestion comes from exactly (bcc for sure?). How does the error message look like?

CC to bcc mailing list as well. bpf_probe_read is not allowed in XDP programs. Your comparison may need to comparison not just starting offset, but also including the memory size so the whole write

From: Edward Cree <ecree@...> Date: Wed, 23 Aug 2017 15:07:20 +0100 Series applied, thanks Edward.

<iovisor-dev@...> wrote: the proposals from tracing wiki need to be re-submitted to show up in official plumbers schedule. Please do so

Hi All, Thanks for joining in to the call today. We shared a round of updates, which are included in the notes below. Also please remember that Plumbers is right around the corner! If you

Adds ability to attach a BPF program to a pktgen thread. The program should fill in the contents of each packet from scratch, including checksum. The context passed in is currently in the form of

Acked-by: Daniel Borkmann <daniel@...>

Acked-by: Daniel Borkmann <daniel@...>

Acked-by: Daniel Borkmann <daniel@...>

Acked-by: Daniel Borkmann <daniel@...>

Acked-by: Alexei Starovoitov <ast@...>