On Mon, Jul 23, 2018 at 10:08:08PM +0200, Paul Chaignon wrote:
> On Mon, Jul 23, 2018 at 02:21:05PM -0400, Andrew Wang wrote:
> > Hi
> >
> > I am writing a bpf program for packet processing and have loaded my ingress
> > function at BPF.XDP.
> >
> > I'm updating the destination IPv6 address and want to update the TCP
> > checksum, but when I try to call the helper functions "bpf_csum_diff" or
> > "bpf_l4_csum_replace", I get a "unknown func <function name>". Are these
> > functions not available for XDP program types?
>
> XDP programs cannot use bpf_l4_csum_replace, but they can use
> bpf_csum_diff since commit 205c380 ("bpf: add csum_diff helper to xdp as
> well") which landed in v4.16-rc1.I was thinking maybe those helpers were not available because no skb was construct. But after checking, the helper you're mentionning is in the tc_cls. Also, the csum_diff helper lies in the same switch statement as l4_csum_replace. Can you elaborate on why one can be used and not the other? Thanks! -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#1394): https://lists.iovisor.org/g/iovisor-dev/message/1394 Mute This Topic: https://lists.iovisor.org/mt/23795612/21656 Group Owner: [email protected] Unsubscribe: https://lists.iovisor.org/g/iovisor-dev/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
