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diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst new file mode 100644 index 000000000..a6258bc8e --- /dev/null +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -0,0 +1,161 @@ +================ +bpftool-map +================ +------------------------------------------------------------------------------- +tool for inspection and simple manipulation of eBPF maps +------------------------------------------------------------------------------- + +:Manual section: 8 + +SYNOPSIS +======== + + **bpftool** [*OPTIONS*] **map** *COMMAND* + + *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } } + + *COMMANDS* := + { **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete** + | **pin** | **help** } + +MAP COMMANDS +============= + +| **bpftool** **map { show | list }** [*MAP*] +| **bpftool** **map dump** *MAP* +| **bpftool** **map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] +| **bpftool** **map lookup** *MAP* **key** *DATA* +| **bpftool** **map getnext** *MAP* [**key** *DATA*] +| **bpftool** **map delete** *MAP* **key** *DATA* +| **bpftool** **map pin** *MAP* *FILE* +| **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] +| **bpftool** **map help** +| +| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } +| *DATA* := { [**hex**] *BYTES* } +| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* } +| *VALUE* := { *DATA* | *MAP* | *PROG* } +| *UPDATE_FLAGS* := { **any** | **exist** | **noexist** } + +DESCRIPTION +=========== + **bpftool map { show | list }** [*MAP*] + Show information about loaded maps. If *MAP* is specified + show information only about given map, otherwise list all + maps currently loaded on the system. + + Output will start with map ID followed by map type and + zero or more named attributes (depending on kernel version). + + **bpftool map dump** *MAP* + Dump all entries in a given *MAP*. + + **bpftool map update** *MAP* **key** *DATA* **value** *VALUE* [*UPDATE_FLAGS*] + Update map entry for a given *KEY*. + + *UPDATE_FLAGS* can be one of: **any** update existing entry + or add if doesn't exit; **exist** update only if entry already + exists; **noexist** update only if entry doesn't exist. + + If the **hex** keyword is provided in front of the bytes + sequence, the bytes are parsed as hexadeximal values, even if + no "0x" prefix is added. If the keyword is not provided, then + the bytes are parsed as decimal values, unless a "0x" prefix + (for hexadecimal) or a "0" prefix (for octal) is provided. + + **bpftool map lookup** *MAP* **key** *DATA* + Lookup **key** in the map. + + **bpftool map getnext** *MAP* [**key** *DATA*] + Get next key. If *key* is not specified, get first key. + + **bpftool map delete** *MAP* **key** *DATA* + Remove entry from the map. + + **bpftool map pin** *MAP* *FILE* + Pin map *MAP* as *FILE*. + + Note: *FILE* must be located in *bpffs* mount. + + **bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*] + Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map. + + Install perf rings into a perf event array map and dump + output of any bpf_perf_event_output() call in the kernel. + By default read the number of CPUs on the system and + install perf ring for each CPU in the corresponding index + in the array. + + If **cpu** and **index** are specified, install perf ring + for given **cpu** at **index** in the array (single ring). + + Note that installing a perf ring into an array will silently + replace any existing ring. Any other application will stop + receiving events if it installed its rings earlier. + + **bpftool map help** + Print short help message. + +OPTIONS +======= + -h, --help + Print short generic help message (similar to **bpftool help**). + + -v, --version + Print version number (similar to **bpftool version**). + + -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**. + + -f, --bpffs + Show file names of pinned maps. + +EXAMPLES +======== +**# bpftool map show** +:: + + 10: hash name some_map flags 0x0 + key 4B value 8B max_entries 2048 memlock 167936B + +The following three commands are equivalent: + +| +| **# bpftool map update id 10 key hex 20 c4 b7 00 value hex 0f ff ff ab 01 02 03 4c** +| **# bpftool map update id 10 key 0x20 0xc4 0xb7 0x00 value 0x0f 0xff 0xff 0xab 0x01 0x02 0x03 0x4c** +| **# bpftool map update id 10 key 32 196 183 0 value 15 255 255 171 1 2 3 76** + +**# bpftool map lookup id 10 key 0 1 2 3** + +:: + + key: 00 01 02 03 value: 00 01 02 03 04 05 06 07 + + +**# bpftool map dump id 10** +:: + + key: 00 01 02 03 value: 00 01 02 03 04 05 06 07 + key: 0d 00 07 00 value: 02 00 00 00 01 02 03 04 + Found 2 elements + +**# bpftool map getnext id 10 key 0 1 2 3** +:: + + key: + 00 01 02 03 + next key: + 0d 00 07 00 + +| +| **# mount -t bpf none /sys/fs/bpf/** +| **# bpftool map pin id 10 /sys/fs/bpf/map** +| **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00** + +SEE ALSO +======== + **bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-cgroup**\ (8) |