-- Andrii
On Fri, Mar 26, 2021 at 2:43 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> writes:
>
> > On Thu, Mar 25, 2021 at 2:11 PM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
> >>
> >> This adds a selftest to check that the verifier rejects a TCP CC struct_ops
> >> with a non-GPL license.
> >>
> >> v2:
> >> - Use a minimal struct_ops BPF program instead of rewriting bpf_dctcp's
> >> license in memory.
> >> - Check for the verifier reject message instead of just the return code.
> >>
> >> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> >> ---
> >> .../selftests/bpf/prog_tests/bpf_tcp_ca.c | 44 +++++++++++++++++++
> >> .../selftests/bpf/progs/bpf_nogpltcp.c | 19 ++++++++
> >> 2 files changed, 63 insertions(+)
> >> create mode 100644 tools/testing/selftests/bpf/progs/bpf_nogpltcp.c
> >>
> >> diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> >> index 37c5494a0381..a09c716528e1 100644
> >> --- a/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> >> +++ b/tools/testing/selftests/bpf/prog_tests/bpf_tcp_ca.c
> >> @@ -6,6 +6,7 @@
> >> #include <test_progs.h>
> >> #include "bpf_dctcp.skel.h"
> >> #include "bpf_cubic.skel.h"
> >> +#include "bpf_nogpltcp.skel.h"
> >
> > total nit, but my eyes can't read "nogpltcp"... wouldn't
> > "bpf_tcp_nogpl" be a bit easier?
>
> Haha, yeah, good point - my eyes also just lump it into a blob...
thanks
>
> >>
> >> #define min(a, b) ((a) < (b) ? (a) : (b))
> >>
> >> @@ -227,10 +228,53 @@ static void test_dctcp(void)
> >> bpf_dctcp__destroy(dctcp_skel);
> >> }
> >>
> >> +static char *err_str = NULL;
> >> +static bool found = false;
> >> +
> >> +static int libbpf_debug_print(enum libbpf_print_level level,
> >> + const char *format, va_list args)
> >> +{
> >> + char *log_buf;
> >> +
> >> + if (level != LIBBPF_WARN ||
> >> + strcmp(format, "libbpf: \n%s\n")) {
> >> + vprintf(format, args);
> >> + return 0;
> >> + }
> >> +
> >> + log_buf = va_arg(args, char *);
> >> + if (!log_buf)
> >> + goto out;
> >> + if (err_str && strstr(log_buf, err_str) != NULL)
> >> + found = true;
> >> +out:
> >> + printf(format, log_buf);
> >> + return 0;
> >> +}
> >> +
> >> +static void test_invalid_license(void)
> >> +{
> >> + libbpf_print_fn_t old_print_fn = NULL;
> >> + struct bpf_nogpltcp *skel;
> >> +
> >> + err_str = "struct ops programs must have a GPL compatible license";
> >> + old_print_fn = libbpf_set_print(libbpf_debug_print);
> >> +
> >> + skel = bpf_nogpltcp__open_and_load();
> >> + if (CHECK(skel, "bpf_nogplgtcp__open_and_load()", "didn't fail\n"))
> >
> > ASSERT_OK_PTR()
> >
> >> + bpf_nogpltcp__destroy(skel);
> >
> > you should destroy unconditionally
> >
> >> +
> >> + CHECK(!found, "errmsg check", "expected string '%s'", err_str);
> >
> > ASSERT_EQ(found, true, "expected_err_msg");
> >
> > I can never be sure which way CHECK() is checking
>
> Ah, thanks! I always get confused about CHECK() as well! Maybe it should
> be renamed to ASSERT()? But that would require flipping all the if()
> statements around them as well :/
Exactly, it's the opposite of assert (ASSERT_NOT %-), that
CHECK(!found) is "assert not not found", right?) and it throws me off
every. single. time. Ideally we complete the set of ASSERT_XXX()
macros and convert as much as possible to that. We can also have just
generic ASSERT() for all other complicated cases.
>
> -Toke
>
