1BPFTOOL-FEATURE(8)                                          BPFTOOL-FEATURE(8)
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NAME

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

10          bpftool [OPTIONS] feature COMMAND
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12          OPTIONS := { { -j | --json } [{ -p | --pretty }] | { -d | --debug  }
13          }
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15          COMMANDS := { probe | help }
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FEATURE COMMANDS

18       bpftool feature probe [COMPONENT] [full] [unprivileged] [macros [prefix PREFIX]]
19       bpftool feature help
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21       COMPONENT := { kernel | dev NAME }
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DESCRIPTION

25          bpftool feature probe [kernel] [full] [macros [prefix PREFIX]]
26                 Probe  the  running  kernel and dump a number of eBPF-related
27                 parameters, such as availability of the  bpf()  system  call,
28                 JIT  status,  eBPF  program  types  availability, eBPF helper
29                 functions availability, and more.
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31                 By   default,   bpftool   does    not    run    probes    for
32                 bpf_probe_write_user()  and  bpf_trace_printk() helpers which
33                 print warnings to kernel logs. To enable  them  and  run  all
34                 probes, the full keyword should be used.
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36                 If  the  macros  keyword (but not the -j option) is passed, a
37                 subset of the output is dumped as a list  of  #define  macros
38                 that  are  ready to be included in a C header file, for exam‐
39                 ple. If, additionally, prefix is used to define a PREFIX, the
40                 provided  string will be used as a prefix to the names of the
41                 macros: this can be used to avoid conflicts  on  macro  names
42                 when including the output of this command as a header file.
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44                 Keyword  kernel  can be omitted. If no probe target is speci‐
45                 fied, probing the kernel is the default behaviour.
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47                 When the unprivileged keyword is used, bpftool will dump only
48                 the  features  available  to  a  user  who  does not have the
49                 CAP_SYS_ADMIN capability set. The features available in  that
50                 case  usually represent a small subset of the parameters sup‐
51                 ported by the system. Unprivileged users MUST use the unpriv‐
52                 ileged  keyword:  This is to avoid misdetection if bpftool is
53                 inadvertently run as non-root, for example. This  keyword  is
54                 unavailable if bpftool was compiled without libcap.
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56          bpftool feature probe dev NAME [full] [macros [prefix PREFIX]]
57                 Probe network device for supported eBPF features and dump re‐
58                 sults to the console.
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60                 The keywords full, macros and prefix have the  same  role  as
61                 when probing the kernel.
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63          bpftool feature help
64                 Print short help message.
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OPTIONS

67          -h, --help
68                 Print short help message (similar to bpftool help).
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70          -V, --version
71                 Print  version  number  (similar to bpftool version), and op‐
72                 tional features that were included when bpftool was compiled.
73                 Optional  features  include linking against libbfd to provide
74                 the disassembler for  JIT-ted  programs  (bpftool  prog  dump
75                 jited) and usage of BPF skeletons (some features like bpftool
76                 prog profile or showing pids associated to  BPF  objects  may
77                 rely on it).
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79          -j, --json
80                 Generate  JSON output. For commands that cannot produce JSON,
81                 this option has no effect.
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83          -p, --pretty
84                 Generate human-readable JSON output. Implies -j.
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86          -d, --debug
87                 Print all logs available, even debug-level information.  This
88                 includes  logs from libbpf as well as from the verifier, when
89                 attempting to load programs.
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SEE ALSO

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