NAME

       bpftool-feature  -  tool for inspection of eBPF-related parameters for Linux kernel or net
       device

SYNOPSIS

       bpftool [OPTIONS] feature COMMAND

       OPTIONS := { { -j | --json } [{ -p | --pretty }] | { -d | --debug } }

       COMMANDS := { probe | help }

FEATURE COMMANDS

       bpftool feature probe [COMPONENT] [full] [unprivileged] [macros [prefix PREFIX]]
       bpftool feature list_builtins GROUP
       bpftool feature help

       COMPONENT := { kernel | dev NAME }
       GROUP := { prog_types | map_types | attach_types | link_types | helpers }

DESCRIPTION

       bpftool feature probe [kernel] [full] [macros [prefix PREFIX]]
              Probe the running kernel and dump a number  of  eBPF-related  parameters,  such  as
              availability of the bpf() system call, JIT status, eBPF program types availability,
              eBPF helper functions availability, and more.

              By  default,  bpftool  does  not  run   probes   for   bpf_probe_write_user()   and
              bpf_trace_printk() helpers which print warnings to kernel logs.  To enable them and
              run all probes, the full keyword should be used.

              If the macros keyword (but not the -j option) is passed, a subset of the output  is
              dumped  as  a  list  of  #define macros that are ready to be included in a C header
              file, for example. If, additionally,  prefix  is  used  to  define  a  PREFIX,  the
              provided  string  will  be used as a prefix to the names of the macros: this can be
              used to avoid conflicts on macro names when including the output of this command as
              a header file.

              Keyword  kernel can be omitted. If no probe target is specified, probing the kernel
              is the default behaviour.

              When the unprivileged  keyword  is  used,  bpftool  will  dump  only  the  features
              available  to  a  user  who  does  not  have  the CAP_SYS_ADMIN capability set. The
              features available in that case usually represent a small subset of the  parameters
              supported by the system. Unprivileged users MUST use the unprivileged keyword: This
              is to avoid misdetection if bpftool is inadvertently run as non-root, for  example.
              This keyword is unavailable if bpftool was compiled without libcap.

       bpftool feature probe dev NAME [full] [macros [prefix PREFIX]]
              Probe network device for supported eBPF features and dump results to the console.

              The keywords full, macros and prefix have the same role as when probing the kernel.

       bpftool feature list_builtins GROUP
              List  items  known to bpftool. These can be BPF program types (prog_types), BPF map
              types (map_types), attach types (attach_types), link  types  (link_types),  or  BPF
              helper functions (helpers). The command does not probe the system, but simply lists
              the elements that bpftool knows from compilation time, as provided from libbpf (for
              all  object  types) or from the BPF UAPI header (list of helpers). This can be used
              in scripts to iterate over BPF types or helpers.

       bpftool feature help
              Print short help message.

OPTIONS

       -h, --help
              Print short help message (similar to bpftool help).

       -V, --version
              Print bpftool's version number (similar to bpftool  version),  the  number  of  the
              libbpf  version  in  use, and optional features that were included when bpftool was
              compiled. Optional features include linking against LLVM or libbfd to  provide  the
              disassembler  for  JIT-ted  programs  (bpftool  prog  dump  jited) and usage of BPF
              skeletons (some features like bpftool prog profile or showing  pids  associated  to
              BPF objects may rely on it).

       -j, --json
              Generate  JSON  output.  For  commands that cannot produce JSON, this option has no
              effect.

       -p, --pretty
              Generate human-readable JSON output. Implies -j.

       -d, --debug
              Print all logs available, even debug-level information.  This  includes  logs  from
              libbpf as well as from the verifier, when attempting to load programs.

SEE ALSO

       bpf(2),  bpf-helpers(7),  bpftool(8),  bpftool-btf(8),  bpftool-cgroup(8), bpftool-gen(8),
       bpftool-iter(8),   bpftool-link(8),   bpftool-map(8),   bpftool-net(8),   bpftool-perf(8),
       bpftool-prog(8), bpftool-struct_ops(8)

                                                                               BPFTOOL-FEATURE(8)