Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > > Tag and program id are dumped to userspace on 'list' to allow to see which > > program is in use in case the filename isn't available/present. > > It seems a bit odd to include the file path in the kernel as well. Its needed to be able to re-load the ruleset. > For > one thing, the same object can be pinned multiple times in different > paths (even in different mount namespaces), Sure. > and there's also nothing > preventing a different program to have been substituted by the pinned > one by the time the value is echoed back. Yes, but what would you expect it should do? > Also, there's nothing checking that the path attribute actually contains > a path, so it's really just an arbitrary label that the kernel promises > to echo back Yes exactly. > But doesn't NFT already have a per-rule comment feature, > so why add another specifically for BPF? You can attach up to 256 bytes to a rule, yes. Might not be enough for a longer path, and there could be multiple expressions in the same rule. This way was the most simple solution. > Instead we could just teach the > userspace utility to extract metadata from the BPF program (based on the > ID) like bpftool does. This would include the program name, BTW, so it > does have a semantic identifier. Sure, I could change the grammar so it expects a tag or ID, e.g. 'ebpf id 42' If thats preferred, I can change this, it avoids the need for storing the name. > > cbpf bytecode isn't supported. > > add rule ... ebpf pinned "/sys/fs/bpf/myprog" > > Any plan to also teach the nft binary to load a BPF program from an ELF > file (instead of relying on pinning)? I used pinning because that is what '-m bpf' uses.
