Message ID | 158194342478.104074.6851588870108514192.stgit@xdp-tutorial |
---|---|
State | Changes Requested |
Delegated to: | BPF Maintainers |
Headers | show |
Series | libbpf: Add support for dynamic program attach target | expand |
On Mon, Feb 17, 2020 at 5:03 AM Eelco Chaudron <echaudro@redhat.com> wrote: > > Use the new bpf_program__set_attach_target() API in the xdp_bpf2bpf > selftest so it can be referenced as an example on how to use it. > > nit: extra empty line? > Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> > Signed-off-by: Eelco Chaudron <echaudro@redhat.com> > --- > .../testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c | 16 +++++++++++++--- > .../testing/selftests/bpf/progs/test_xdp_bpf2bpf.c | 4 ++-- > 2 files changed, 15 insertions(+), 5 deletions(-) > > diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c > index 6b56bdc73ebc..513fdbf02b81 100644 > --- a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c > +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c > @@ -14,7 +14,7 @@ void test_xdp_bpf2bpf(void) > struct test_xdp *pkt_skel = NULL; > struct test_xdp_bpf2bpf *ftrace_skel = NULL; > struct vip key4 = {.protocol = 6, .family = AF_INET}; > - DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); > + struct bpf_program *prog; > > /* Load XDP program to introspect */ > pkt_skel = test_xdp__open_and_load(); > @@ -27,11 +27,21 @@ void test_xdp_bpf2bpf(void) > bpf_map_update_elem(map_fd, &key4, &value4, 0); > > /* Load trace program */ > - opts.attach_prog_fd = pkt_fd, > - ftrace_skel = test_xdp_bpf2bpf__open_opts(&opts); > + ftrace_skel = test_xdp_bpf2bpf__open(); > if (CHECK(!ftrace_skel, "__open", "ftrace skeleton failed\n")) > goto out; > > + /* Demonstrate the bpf_program__set_attach_target() API rather than > + * the load with options, i.e. opts.attach_prog_fd. > + */ > + prog = *ftrace_skel->skeleton->progs[0].prog; it took me a while to understand what's going on here... :) You are not supposed to peek into ftrace_skel->skeleton, it's an "internal" object that's passed into libbpf. It's better to write it as a nice and short: prog = ftrace_skel->progs.trace_on_entry; > + bpf_program__set_expected_attach_type(prog, BPF_TRACE_FENTRY); > + bpf_program__set_attach_target(prog, pkt_fd, "_xdp_tx_iptunnel"); > + > + prog = *ftrace_skel->skeleton->progs[1].prog; same as above: ftrace_skel->progs.trace_on_exit > + bpf_program__set_expected_attach_type(prog, BPF_TRACE_FEXIT); > + bpf_program__set_attach_target(prog, pkt_fd, "_xdp_tx_iptunnel"); > + > err = test_xdp_bpf2bpf__load(ftrace_skel); > if (CHECK(err, "__load", "ftrace skeleton failed\n")) > goto out; > diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c > index cb8a04ab7a78..b840fc9e3ed5 100644 > --- a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c > +++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c > @@ -28,7 +28,7 @@ struct xdp_buff { > } __attribute__((preserve_access_index)); > > __u64 test_result_fentry = 0; > -SEC("fentry/_xdp_tx_iptunnel") > +SEC("fentry/FUNC") > int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) > { > test_result_fentry = xdp->rxq->dev->ifindex; > @@ -36,7 +36,7 @@ int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) > } > > __u64 test_result_fexit = 0; > -SEC("fexit/_xdp_tx_iptunnel") > +SEC("fexit/FUNC") > int BPF_PROG(trace_on_exit, struct xdp_buff *xdp, int ret) > { > test_result_fexit = ret; >
On 18 Feb 2020, at 22:21, Andrii Nakryiko wrote: > On Mon, Feb 17, 2020 at 5:03 AM Eelco Chaudron <echaudro@redhat.com> wrote: >> >> Use the new bpf_program__set_attach_target() API in the xdp_bpf2bpf >> selftest so it can be referenced as an example on how to use it. >> >> > > nit: extra empty line? ACK <SNIP> >> + prog = *ftrace_skel->skeleton->progs[0].prog; > > it took me a while to understand what's going on here... :) You are > not supposed to peek into ftrace_skel->skeleton, it's an "internal" > object that's passed into libbpf. > > It's better to write it as a nice and short: > > prog = ftrace_skel->progs.trace_on_entry; > Will change in next rev…
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c index 6b56bdc73ebc..513fdbf02b81 100644 --- a/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c +++ b/tools/testing/selftests/bpf/prog_tests/xdp_bpf2bpf.c @@ -14,7 +14,7 @@ void test_xdp_bpf2bpf(void) struct test_xdp *pkt_skel = NULL; struct test_xdp_bpf2bpf *ftrace_skel = NULL; struct vip key4 = {.protocol = 6, .family = AF_INET}; - DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); + struct bpf_program *prog; /* Load XDP program to introspect */ pkt_skel = test_xdp__open_and_load(); @@ -27,11 +27,21 @@ void test_xdp_bpf2bpf(void) bpf_map_update_elem(map_fd, &key4, &value4, 0); /* Load trace program */ - opts.attach_prog_fd = pkt_fd, - ftrace_skel = test_xdp_bpf2bpf__open_opts(&opts); + ftrace_skel = test_xdp_bpf2bpf__open(); if (CHECK(!ftrace_skel, "__open", "ftrace skeleton failed\n")) goto out; + /* Demonstrate the bpf_program__set_attach_target() API rather than + * the load with options, i.e. opts.attach_prog_fd. + */ + prog = *ftrace_skel->skeleton->progs[0].prog; + bpf_program__set_expected_attach_type(prog, BPF_TRACE_FENTRY); + bpf_program__set_attach_target(prog, pkt_fd, "_xdp_tx_iptunnel"); + + prog = *ftrace_skel->skeleton->progs[1].prog; + bpf_program__set_expected_attach_type(prog, BPF_TRACE_FEXIT); + bpf_program__set_attach_target(prog, pkt_fd, "_xdp_tx_iptunnel"); + err = test_xdp_bpf2bpf__load(ftrace_skel); if (CHECK(err, "__load", "ftrace skeleton failed\n")) goto out; diff --git a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c index cb8a04ab7a78..b840fc9e3ed5 100644 --- a/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c +++ b/tools/testing/selftests/bpf/progs/test_xdp_bpf2bpf.c @@ -28,7 +28,7 @@ struct xdp_buff { } __attribute__((preserve_access_index)); __u64 test_result_fentry = 0; -SEC("fentry/_xdp_tx_iptunnel") +SEC("fentry/FUNC") int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) { test_result_fentry = xdp->rxq->dev->ifindex; @@ -36,7 +36,7 @@ int BPF_PROG(trace_on_entry, struct xdp_buff *xdp) } __u64 test_result_fexit = 0; -SEC("fexit/_xdp_tx_iptunnel") +SEC("fexit/FUNC") int BPF_PROG(trace_on_exit, struct xdp_buff *xdp, int ret) { test_result_fexit = ret;