On Mon, Dec 13, 2021 at 8:28 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > > Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> writes: > > > On Sat, Dec 11, 2021 at 10:43 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > >> > >> This adds an XDP-based traffic generator sample which uses the DO_REDIRECT > >> flag of bpf_prog_run(). It works by building the initial packet in > >> userspace and passing it to the kernel where an XDP program redirects the > >> packet to the target interface. The traffic generator supports two modes of > >> operation: one that just sends copies of the same packet as fast as it can > >> without touching the packet data at all, and one that rewrites the > >> destination port number of each packet, making the generated traffic span a > >> range of port numbers. > >> > >> The dynamic mode is included to demonstrate how the bpf_prog_run() facility > >> enables building a completely programmable packet generator using XDP. > >> Using the dynamic mode has about a 10% overhead compared to the static > >> mode, because the latter completely avoids touching the page data. > >> > >> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> > >> --- > >> samples/bpf/.gitignore | 1 + > >> samples/bpf/Makefile | 4 + > >> samples/bpf/xdp_redirect.bpf.c | 34 +++ > >> samples/bpf/xdp_trafficgen_user.c | 421 ++++++++++++++++++++++++++++++ > >> 4 files changed, 460 insertions(+) > >> create mode 100644 samples/bpf/xdp_trafficgen_user.c > > > > I think it deserves to be in tools/bpf/ > > samples/bpf/ bit rots too often now. > > imo everything in there either needs to be converted to selftests/bpf > > or deleted. > > I think there's value in having a separate set of utilities that are > more user-facing than the selftests. But I do agree that it's annoying > they bit rot. So how about we fix that instead? Andrii suggested just > integrating the build of samples/bpf into selftests[0], so I'll look > into that after the holidays. But in the meantime I don't think there's > any harm in adding this utility here? I think samples/bpf building would help to stabilize bitroting, but the question of the right home for this trafficgen tool remains. I think it's best to keep it outside of the kernel tree. It's not any more special than all other libbpf and bcc tools. I think xdp-tools repo or bcc could be a home for it.
