On Fri, 04 Oct 2019 19:22:42 +0200, Toke Høiland-Jørgensen wrote: > From: Alan Maguire <alan.maguire@xxxxxxxxxx> > > This adds support for setting and deleting bpf chain call programs through > a couple of new commands in the bpf() syscall. The CHAIN_ADD and CHAIN_DEL > commands take two eBPF program fds and a return code, and install the > 'next' program to be chain called after the 'prev' program if that program > returns 'retcode'. A retcode of -1 means "wildcard", so that the program > will be executed regardless of the previous program's return code. > > > The syscall command names are based on Alexei's prog_chain example[0], > which Alan helpfully rebased on current bpf-next. However, the logic and > program storage is obviously adapted to the execution logic in the previous > commit. > > [0] https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git/commit/?h=prog_chain&id=f54f45d00f91e083f6aec2abe35b6f0be52ae85b&context=15 > > Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> It'd be good to explain why not just allocate a full prog array (or in fact get one from the user), instead of having a hidden one which requires new command to interact with?
