Manual: bpftool-feature

bpftool-feature(8)				   System Manager's Manual				  bpftool-feature(8)

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() sys‐
	      tem 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 de‐
	      fine 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 op‐
	      tional 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 skele‐
	      tons (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-to‐
       ken(8)

													  bpftool-feature(8)