bpftool/Documentation/bpftool-map.rst

1 .. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
4 bpftool-map
6 -------------------------------------------------------------------------------
8 -------------------------------------------------------------------------------
19 *OPTIONS* := { |COMMON_OPTIONS| | { **-f** | **--bpffs** } | { **-n** | **--nomount** } }
29 | **bpftool** **map create**     *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
33 | **bpftool** **map update**     *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
34 | **bpftool** **map lookup**     *MAP* [**key** *DATA*]
35 | **bpftool** **map getnext**    *MAP* [**key** *DATA*]
36 | **bpftool** **map delete**     *MAP*  **key** *DATA*
40 | **bpftool** **map push**       *MAP* **value** *VALUE*
42 | **bpftool** **map enqueue**    *MAP* **value** *VALUE*
50 | *VALUE* := { *DATA* | *MAP* | *PROG* }
75 bpftool map create *FILE* type *TYPE* key *KEY_SIZE* value *VALUE_SIZE*  entries *MAX_ENTRIES* name…
82     To create maps of type array-of-maps or hash-of-maps, the **inner_map**
93 bpftool map update  *MAP* [key *DATA*] [value *VALUE*] [*UPDATE_FLAGS*]
94     Update map entry for a given *KEY*.
106 bpftool map lookup  *MAP* [key *DATA*]
107     Lookup **key** in the map.
109 bpftool map getnext *MAP* [key *DATA*]
110     Get next key.  If *key* is not specified, get first key.
112 bpftool map delete  *MAP*  key *DATA*
137     Peek next value in the queue or stack.
139 bpftool map push  *MAP* value *VALUE*
140     Push *VALUE* onto the stack.
143     Pop and print value from the stack.
145 bpftool map enqueue  *MAP* value *VALUE*
146     Enqueue *VALUE* into the queue.
149     Dequeue and print value from the queue.
152     Freeze the map as read-only from user space. Entries from a frozen map can
165 -f, --bpffs
168 -n, --nomount
179         key 4B  value 8B  max_entries 2048  memlock 167936B
185 | **# bpftool map update id 10 key hex   20   c4   b7   00 value hex   0f   ff   ff   ab   01   02 …
186 | **# bpftool map update id 10 key     0x20 0xc4 0xb7 0x00 value     0x0f 0xff 0xff 0xab 0x01 0x02 …
187 | **# bpftool map update id 10 key       32  196  183    0 value       15  255  255  171    1    2 …
189 **# bpftool map lookup id 10 key 0 1 2 3**
193   key: 00 01 02 03 value: 00 01 02 03 04 05 06 07
200   key: 00 01 02 03  value: 00 01 02 03 04 05 06 07
201   key: 0d 00 07 00  value: 02 00 00 00 01 02 03 04
204 **# bpftool map getnext id 10 key 0 1 2 3**
208   key:
210   next key:
214 | **# mount -t bpf none /sys/fs/bpf/**
216 | **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00**
220 programs used for tail-call jumps at runtime, without having to reload the
221 entry-point program. Below is an example for this use case: we load a program
231 | **# bpftool prog --bpffs**
236           loaded_at 2018-12-12T15:02:58+0000  uid 0
240           loaded_at 2018-12-12T15:02:58+0000  uid 0
244           loaded_at 2018-12-12T15:02:58+0000  uid 0
253           key 4B  value 4B  max_entries 1  memlock 4096B
265 | **# bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug**
270   key: 00 00 00 00  value: 22 02 00 00