xref: /linux/tools/bpf/bpftool/Documentation/bpftool-map.rst (revision a8b70ccf10e38775785d9cb12ead916474549f99)
1================
2bpftool-map
3================
4-------------------------------------------------------------------------------
5tool for inspection and simple manipulation of eBPF maps
6-------------------------------------------------------------------------------
7
8:Manual section: 8
9
10SYNOPSIS
11========
12
13	**bpftool** [*OPTIONS*] **map** *COMMAND*
14
15	*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-f** | **--bpffs** } }
16
17	*COMMANDS* :=
18	{ **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete**
19	| **pin** | **help** }
20
21MAP COMMANDS
22=============
23
24|	**bpftool** **map { show | list }**   [*MAP*]
25|	**bpftool** **map dump**    *MAP*
26|	**bpftool** **map update**  *MAP*  **key** *BYTES*   **value** *VALUE* [*UPDATE_FLAGS*]
27|	**bpftool** **map lookup**  *MAP*  **key** *BYTES*
28|	**bpftool** **map getnext** *MAP* [**key** *BYTES*]
29|	**bpftool** **map delete**  *MAP*  **key** *BYTES*
30|	**bpftool** **map pin**     *MAP*  *FILE*
31|	**bpftool** **map help**
32|
33|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
34|	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
35|	*VALUE* := { *BYTES* | *MAP* | *PROG* }
36|	*UPDATE_FLAGS* := { **any** | **exist** | **noexist** }
37
38DESCRIPTION
39===========
40	**bpftool map { show | list }**   [*MAP*]
41		  Show information about loaded maps.  If *MAP* is specified
42		  show information only about given map, otherwise list all
43		  maps currently loaded on the system.
44
45		  Output will start with map ID followed by map type and
46		  zero or more named attributes (depending on kernel version).
47
48	**bpftool map dump**    *MAP*
49		  Dump all entries in a given *MAP*.
50
51	**bpftool map update**  *MAP*  **key** *BYTES*   **value** *VALUE* [*UPDATE_FLAGS*]
52		  Update map entry for a given *KEY*.
53
54		  *UPDATE_FLAGS* can be one of: **any** update existing entry
55		  or add if doesn't exit; **exist** update only if entry already
56		  exists; **noexist** update only if entry doesn't exist.
57
58	**bpftool map lookup**  *MAP*  **key** *BYTES*
59		  Lookup **key** in the map.
60
61	**bpftool map getnext** *MAP* [**key** *BYTES*]
62		  Get next key.  If *key* is not specified, get first key.
63
64	**bpftool map delete**  *MAP*  **key** *BYTES*
65		  Remove entry from the map.
66
67	**bpftool map pin**     *MAP*  *FILE*
68		  Pin map *MAP* as *FILE*.
69
70		  Note: *FILE* must be located in *bpffs* mount.
71
72	**bpftool map help**
73		  Print short help message.
74
75OPTIONS
76=======
77	-h, --help
78		  Print short generic help message (similar to **bpftool help**).
79
80	-v, --version
81		  Print version number (similar to **bpftool version**).
82
83	-j, --json
84		  Generate JSON output. For commands that cannot produce JSON, this
85		  option has no effect.
86
87	-p, --pretty
88		  Generate human-readable JSON output. Implies **-j**.
89
90	-f, --bpffs
91		  Show file names of pinned maps.
92
93EXAMPLES
94========
95**# bpftool map show**
96::
97
98  10: hash  name some_map  flags 0x0
99	key 4B  value 8B  max_entries 2048  memlock 167936B
100
101**# bpftool map update id 10 key 13 00 07 00 value 02 00 00 00 01 02 03 04**
102
103**# bpftool map lookup id 10 key 0 1 2 3**
104
105::
106
107  key: 00 01 02 03 value: 00 01 02 03 04 05 06 07
108
109
110**# bpftool map dump id 10**
111::
112
113  key: 00 01 02 03  value: 00 01 02 03 04 05 06 07
114  key: 0d 00 07 00  value: 02 00 00 00 01 02 03 04
115  Found 2 elements
116
117**# bpftool map getnext id 10 key 0 1 2 3**
118::
119
120  key:
121  00 01 02 03
122  next key:
123  0d 00 07 00
124
125|
126| **# mount -t bpf none /sys/fs/bpf/**
127| **# bpftool map pin id 10 /sys/fs/bpf/map**
128| **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00**
129
130SEE ALSO
131========
132	**bpftool**\ (8), **bpftool-prog**\ (8), **bpftool-cgroup**\ (8)
133