advanced03-AF_XDP does not compile missing header file xsk.h

[netoptimizer]

The advanced03-AF_XDP example/assignment does not compile on my system. It is missing a header include file named: bpf/xsk.h.

Output is:

advanced03-AF_XDP]$ make
cc -Wall -I../libbpf/src//root/usr/include/ -g -I/usr/include/x86_64-linux-gnu -I../headers/ -L../libbpf/src/ -o af_xdp_user ../common//common_params.o ../common//common_user_bpf_xdp.o \
 af_xdp_user.c -l:libbpf.a -lelf  -lpthread
af_xdp_user.c:19:10: fatal error: bpf/xsk.h: No such file or directory
 #include <bpf/xsk.h>
          ^~~~~~~~~~~
compilation terminated.
make: *** [../common//common.mk:105: af_xdp_user] Error 1

The header file xsk.h is provided by libbpf, but not under subdir bpf/. In my git tree the file is located in: libbpf/src/xsk.h and XDP-tutorial does have this (../libbpf/src/) as object search/link dir in above compile command.

I guess libbpf should have "installed" this header file in: ../libbpf/src//root/usr/include/ but it only contains:

$ ls -1 libbpf/src//root/usr/include/bpf/
bpf.h
btf.h
libbpf.h

[netoptimizer]

I do have the latest libbpf version:

$ git submodule status 
 476e158b07ea5f36f4475735330c1152ffe15acc libbpf (v0.0.4-46-g476e158b07ea)

This is (currently) the latest commit for libbpf.

[netoptimizer]

Hmm... this was weird, after above mentioned commit dbd66f1 and compiling all assignments successfully, somehow libbpf were also "re-installed", and now my local libbpf/src//root/usr/include/bpf/ dir contains:

$ ls -1 libbpf/src//root/usr/include/bpf/
bpf.h
btf.h
libbpf.h
libbpf_util.h
xsk.h

And now, the advanced03-AF_XDP example compiles.

[chaudron]

Is this still a problem based on #73 comment? I tried it using the vagrant method from this pull request and do not get the errors #70

[chaudron]

Any update on the above @netoptimizer? As it works fine in my setup

[netoptimizer]

Notice that in commit 064365f I renamed libbpf install path from root to build

From: libbpf/src/root/usr/include/bpf/
To:   libbpf/src/build/usr/include/bpf/

[netoptimizer]

I'm going to close this, because this was a case of stalled files from other libbpf submodule checkouts.

In commit 064365f have tried to fix this by having make clean also removing the build version of libbpf. If people hit this again, we first as them to run make clean and try again.

I didn't find a way to create a Makefile dependency that can detect that libbpf submodule was changed, and force a rebuild of the libbpf build dir.

[tohojo]

Jesper Dangaard Brouer <[email protected]> writes:

I didn't find a way to create a Makefile dependency that can detect that libbpf submodule was changed, and force a rebuild of the libbpf build dir.

I was thinking about trying out git-subtrac: https://github.com/apenwarr/git-subtrac This should make it easier to track the submodule dependency correctly; not sure if it'll solve this particular problem, but it may be worth testing it?

[netoptimizer]

No, please don't.

This is a tutorial that needs to be easy to get started with, I don't want people/users to depend on installing a git subcommand like subtrac before getting started...

[tohojo]

Jesper Dangaard Brouer <[email protected]> writes:

No, please don't. This is a tutorial that needs to be easy to get started with, I don't want people/users to depend on installing a git subcommand like ```subtrac``` before getting started...

If I understand it correctly, the subtrac binary is only needed for updating the submodule; cloning should just work (and would not need the --recurse-submodules); that is part of the appeal :)