BPFTOOL-FEATURE(8) 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 help
COMPONENT := { kernel | dev NAME }
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 exam-
ple. 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 speci-
fied, 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 sup-
ported by the system. Unprivileged users MUST use the unpriv-
ileged 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 re-
sults to the console.
The keywords full, macros and prefix have the same role as
when probing the kernel.
bpftool feature help
Print short help message.
OPTIONS
-h, --help
Print short help message (similar to bpftool help).
-V, --version
Print version number (similar to bpftool version), and op-
tional features that were included when bpftool was compiled.
Optional features include linking against 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)
Generated by dwww version 1.14 on Thu Jan 23 03:10:39 CET 2025.