On 2/4/20 3:35 PM, Toke Høiland-Jørgensen wrote: > >> Most likely, making iproute2 use libbpf statically is going to be >> challenging and I am not sure it is the right thing to do (unless the >> user is building a static version of iproute2 commands). > > Linking dynamically would imply a new dependency. I'm not necessarily > against that, but would it be acceptable from your PoV? And if so, > should we keep the current internal BPF code for when libbpf is not > available, or would it be acceptable to not be able to load BPF programs > if libbpf is not present (similar to how the libelf dependency works > today)? iproute2 recently gained the libmnl dependency for extack. Seems like libbpf falls into the similar category. > >> 2. git submodules can be a PITA to deal with (e.g., jumping between >> branches and versions), so there needs to be a good reason for it. > > Yes, totally with you on that. Another option could be to just copy the > files into the iproute2 tree, and update them the same way the kernel > headers are? Or maybe doing fancy things like this: > https://github.com/apenwarr/git-subtrac kernel uapi is a totally different reason to import the headers. bpf functionality is an add-on. I would like to see iproute2 work with libbpf. Given libbpf's current status and availability across OS'es that is going to be a challenge for a lot of OS'es which is why I suggested the HAVE_LIBBPF check falls back to existing code if libbpf is not installed. > >> 3. iproute2 code needs to build for a wide range of OSes and not lose >> functionality compared to what it has today. > > Could you be a bit more specific about "a wide range of OSes"? I guess > we could do the work to make sure libbpf builds on all the same > platforms iproute2 supports, but we'd need something a bit more definite > to go on... > rhel5/centos5? definitely rhel6/centos6 time frame and forward. Stephen: has the backwards lifetime ever been stated? Changing configure to check for existence and fall back to existing code seems to me the safest option.
