tools/bpf/bpftool/Documentation/bpftool-map.rst - linux - Git at Google

 ================
 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** | **create** | **dump** | **update** | **lookup** | **getnext**
 	| **delete** | **pin** | **help** }

 MAP COMMANDS
 =============

 |	**bpftool** **map { show | list }**   [*MAP*]
 |	**bpftool** **map create**     *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
 |		**entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
 |	**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 peek**       *MAP*
 |	**bpftool** **map push**       *MAP* **value** *VALUE*
 |	**bpftool** **map pop**        *MAP*
 |	**bpftool** **map enqueue**    *MAP* **value** *VALUE*
 |	**bpftool** **map dequeue**    *MAP*
 |	**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** }
 |	*TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**
 |		| **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash**
 |		| **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps**
 |		| **devmap** | **sockmap** | **cpumap** | **xskmap** | **sockhash**
 |		| **cgroup_storage** | **reuseport_sockarray** | **percpu_cgroup_storage**
 |		| **queue** | **stack** }

 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 create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE*  **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
 		  Create a new map with given parameters and pin it to *bpffs*
 		  as *FILE*.

 	**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. It must not
 		  contain a dot character ('.'), which is reserved for future
 		  extensions of *bpffs*.

 	**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 peek**  *MAP*
 		  Peek next **value** in the queue or stack.

 	**bpftool map push**  *MAP* **value** *VALUE*
 		  Push **value** onto the stack.

 	**bpftool map pop**  *MAP*
 		  Pop and print **value** from the stack.

 	**bpftool map enqueue**  *MAP* **value** *VALUE*
 		  Enqueue **value** into the queue.

 	**bpftool map dequeue**  *MAP*
 		  Dequeue and print **value** from the queue.

 	**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.

 	-n, --nomount
 		  Do not automatically attempt to mount any virtual file system
 		  (such as tracefs or BPF virtual file system) when necessary.

 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**

 Note that map update can also be used in order to change the program references
 hold by a program array map. This can be used, for example, to change the
 programs used for tail-call jumps at runtime, without having to reload the
 entry-point program. Below is an example for this use case: we load a program
 defining a prog array map, and with a main function that contains a tail call
 to other programs that can be used either to "process" packets or to "debug"
 processing. Note that the prog array map MUST be pinned into the BPF virtual
 file system for the map update to work successfully, as kernel flushes prog
 array maps when they have no more references from user space (and the update
 would be lost as soon as bpftool exits).

 |
 | **# bpftool prog loadall tail_calls.o /sys/fs/bpf/foo type xdp**
 | **# bpftool prog --bpffs**

 ::

   545: xdp  name main_func  tag 674b4b5597193dc3  gpl
           loaded_at 2018-12-12T15:02:58+0000  uid 0
           xlated 240B  jited 257B  memlock 4096B  map_ids 294
           pinned /sys/fs/bpf/foo/xdp
   546: xdp  name bpf_func_process  tag e369a529024751fc  gpl
           loaded_at 2018-12-12T15:02:58+0000  uid 0
           xlated 200B  jited 164B  memlock 4096B
           pinned /sys/fs/bpf/foo/process
   547: xdp  name bpf_func_debug  tag 0b597868bc7f0976  gpl
           loaded_at 2018-12-12T15:02:58+0000  uid 0
           xlated 200B  jited 164B  memlock 4096B
           pinned /sys/fs/bpf/foo/debug

 **# bpftool map**

 ::

   294: prog_array  name jmp_table  flags 0x0
           key 4B  value 4B  max_entries 1  memlock 4096B
           owner_prog_type xdp  owner jited

 |
 | **# bpftool map pin id 294 /sys/fs/bpf/bar**
 | **# bpftool map dump pinned /sys/fs/bpf/bar**

 ::

   Found 0 elements

 |
 | **# bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug**
 | **# bpftool map dump pinned /sys/fs/bpf/bar**

 ::

   key: 00 00 00 00  value: 22 02 00 00
   Found 1 element

 SEE ALSO
 ========
 	**bpf**\ (2),
 	**bpf-helpers**\ (7),
 	**bpftool**\ (8),
 	**bpftool-prog**\ (8),
 	**bpftool-cgroup**\ (8),
 	**bpftool-feature**\ (8),
 	**bpftool-net**\ (8),
 	**bpftool-perf**\ (8),
 	**bpftool-btf**\ (8)
	================
	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 \| create \| dump \| update \| lookup \| getnext
	\| delete \| pin \| help }

	MAP COMMANDS
	=============

	\| bpftool map { show \| list } [MAP]
	\| bpftool map create FILE type TYPE key KEY_SIZE value VALUE_SIZE \
	\| entries MAX_ENTRIES name NAME [flags FLAGS] [dev NAME]
	\| 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 peek MAP
	\| bpftool map push MAP value VALUE
	\| bpftool map pop MAP
	\| bpftool map enqueue MAP value VALUE
	\| bpftool map dequeue MAP
	\| 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 }
	\| TYPE := { hash \| array \| prog_array \| perf_event_array \| percpu_hash
	\| \| percpu_array \| stack_trace \| cgroup_array \| lru_hash
	\| \| lru_percpu_hash \| lpm_trie \| array_of_maps \| hash_of_maps
	\| \| devmap \| sockmap \| cpumap \| xskmap \| sockhash
	\| \| cgroup_storage \| reuseport_sockarray \| percpu_cgroup_storage
	\| \| queue \| stack }

	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 create FILE type TYPE key KEY_SIZE value VALUE_SIZE entries MAX_ENTRIES name NAME [flags FLAGS] [dev NAME]
	Create a new map with given parameters and pin it to bpffs
	as FILE.

	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. It must not
	contain a dot character ('.'), which is reserved for future
	extensions of bpffs.

	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 peek MAP
	Peek next value in the queue or stack.

	bpftool map push MAP value VALUE
	Push value onto the stack.

	bpftool map pop MAP
	Pop and print value from the stack.

	bpftool map enqueue MAP value VALUE
	Enqueue value into the queue.

	bpftool map dequeue MAP
	Dequeue and print value from the queue.

	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.

	-n, --nomount
	Do not automatically attempt to mount any virtual file system
	(such as tracefs or BPF virtual file system) when necessary.

	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

	Note that map update can also be used in order to change the program references
	hold by a program array map. This can be used, for example, to change the
	programs used for tail-call jumps at runtime, without having to reload the
	entry-point program. Below is an example for this use case: we load a program
	defining a prog array map, and with a main function that contains a tail call
	to other programs that can be used either to "process" packets or to "debug"
	processing. Note that the prog array map MUST be pinned into the BPF virtual
	file system for the map update to work successfully, as kernel flushes prog
	array maps when they have no more references from user space (and the update
	would be lost as soon as bpftool exits).

	\|
	\| # bpftool prog loadall tail_calls.o /sys/fs/bpf/foo type xdp
	\| # bpftool prog --bpffs

	::

	545: xdp name main_func tag 674b4b5597193dc3 gpl
	loaded_at 2018-12-12T15:02:58+0000 uid 0
	xlated 240B jited 257B memlock 4096B map_ids 294
	pinned /sys/fs/bpf/foo/xdp
	546: xdp name bpf_func_process tag e369a529024751fc gpl
	loaded_at 2018-12-12T15:02:58+0000 uid 0
	xlated 200B jited 164B memlock 4096B
	pinned /sys/fs/bpf/foo/process
	547: xdp name bpf_func_debug tag 0b597868bc7f0976 gpl
	loaded_at 2018-12-12T15:02:58+0000 uid 0
	xlated 200B jited 164B memlock 4096B
	pinned /sys/fs/bpf/foo/debug

	# bpftool map

	::

	294: prog_array name jmp_table flags 0x0
	key 4B value 4B max_entries 1 memlock 4096B
	owner_prog_type xdp owner jited

	\|
	\| # bpftool map pin id 294 /sys/fs/bpf/bar
	\| # bpftool map dump pinned /sys/fs/bpf/bar

	::

	Found 0 elements

	\|
	\| # bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug
	\| # bpftool map dump pinned /sys/fs/bpf/bar

	::

	key: 00 00 00 00 value: 22 02 00 00
	Found 1 element

	SEE ALSO
	========
	bpf\ (2),
	bpf-helpers\ (7),
	bpftool\ (8),
	bpftool-prog\ (8),
	bpftool-cgroup\ (8),
	bpftool-feature\ (8),
	bpftool-net\ (8),
	bpftool-perf\ (8),
	bpftool-btf\ (8)