On Fri, May 15, 2020 at 02:28:30PM +0200, Jakub Sitnicki wrote: > On Mon, May 11, 2020 at 10:44 PM CEST, Alexei Starovoitov wrote: > > On Mon, May 11, 2020 at 08:52:06PM +0200, Jakub Sitnicki wrote: > >> Run a BPF program before looking up a listening socket on the receive path. > >> Program selects a listening socket to yield as result of socket lookup by > >> calling bpf_sk_assign() helper and returning BPF_REDIRECT code. > >> > >> Alternatively, program can also fail the lookup by returning with BPF_DROP, > >> or let the lookup continue as usual with BPF_OK on return. > >> > >> This lets the user match packets with listening sockets freely at the last > >> possible point on the receive path, where we know that packets are destined > >> for local delivery after undergoing policing, filtering, and routing. > >> > >> With BPF code selecting the socket, directing packets destined to an IP > >> range or to a port range to a single socket becomes possible. > >> > >> Suggested-by: Marek Majkowski <marek@xxxxxxxxxxxxxx> > >> Reviewed-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx> > >> Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx> > >> --- > > [...] > > > Also please switch to bpf_link way of attaching. All system wide attachments > > should be visible and easily debuggable via 'bpftool link show'. > > Currently we're converting tc and xdp hooks to bpf_link. This new hook > > should have it from the beginning. > > Just to clarify, I understood that bpf(BPF_PROG_ATTACH/DETACH) doesn't > have to be supported for new hooks. Yes. Not only no need. I don't think attach/detach fits.
