From b22bf1b9979a608827dea98c61ed9ec297bcc513 Mon Sep 17 00:00:00 2001 From: Paul Chaignon Date: Tue, 4 Jan 2022 18:59:29 +0100 Subject: bpftool: Refactor misc. feature probe There is currently a single miscellaneous feature probe, HAVE_LARGE_INSN_LIMIT, to check for the 1M instructions limit in the verifier. Subsequent patches will add additional miscellaneous probes, which follow the same pattern at the existing probe. This patch therefore refactors the probe to avoid code duplication in subsequent patches. The BPF program type and the checked error numbers in the HAVE_LARGE_INSN_LIMIT probe are changed to better generalize to other probes. The feature probe retains its current behavior despite those changes. Signed-off-by: Paul Chaignon Signed-off-by: Daniel Borkmann Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/956c9329a932c75941194f91790d01f31dfbe01b.1641314075.git.paul@isovalent.com --- tools/bpf/bpftool/feature.c | 45 +++++++++++++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 16 deletions(-) (limited to 'tools/bpf') diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c index 6719b9282eca..3da97a02f455 100644 --- a/tools/bpf/bpftool/feature.c +++ b/tools/bpf/bpftool/feature.c @@ -642,6 +642,30 @@ probe_helpers_for_progtype(enum bpf_prog_type prog_type, bool supported_type, printf("\n"); } +static void +probe_misc_feature(struct bpf_insn *insns, size_t len, + const char *define_prefix, __u32 ifindex, + const char *feat_name, const char *plain_name, + const char *define_name) +{ + LIBBPF_OPTS(bpf_prog_load_opts, opts, + .prog_ifindex = ifindex, + ); + bool res; + int fd; + + errno = 0; + fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL", + insns, len, &opts); + res = fd >= 0 || !errno; + + if (fd >= 0) + close(fd); + + print_bool_feature(feat_name, plain_name, define_name, res, + define_prefix); +} + /* * Probe for availability of kernel commit (5.3): * @@ -649,29 +673,18 @@ probe_helpers_for_progtype(enum bpf_prog_type prog_type, bool supported_type, */ static void probe_large_insn_limit(const char *define_prefix, __u32 ifindex) { - LIBBPF_OPTS(bpf_prog_load_opts, opts, - .prog_ifindex = ifindex, - ); struct bpf_insn insns[BPF_MAXINSNS + 1]; - bool res; - int i, fd; + int i; for (i = 0; i < BPF_MAXINSNS; i++) insns[i] = BPF_MOV64_IMM(BPF_REG_0, 1); insns[BPF_MAXINSNS] = BPF_EXIT_INSN(); - errno = 0; - fd = bpf_prog_load(BPF_PROG_TYPE_SCHED_CLS, NULL, "GPL", - insns, ARRAY_SIZE(insns), &opts); - res = fd >= 0 || (errno != E2BIG && errno != EINVAL); - - if (fd >= 0) - close(fd); - - print_bool_feature("have_large_insn_limit", + probe_misc_feature(insns, ARRAY_SIZE(insns), + define_prefix, ifindex, + "have_large_insn_limit", "Large program size limit", - "LARGE_INSN_LIMIT", - res, define_prefix); + "LARGE_INSN_LIMIT"); } static void -- cgit v1.2.3