Provided by: linux-oem-5.6-tools-common_5.6.0-1007.7_all bug

NAME

       bpftool-map - tool for inspection and simple manipulation of eBPF maps

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 freeze     MAP
       bpftool map help

       MAP := { id MAP_ID | pinned FILE | name MAP_NAME }
       DATA := { [hex] BYTES }
       PROG := { id PROG_ID | pinned FILE | tag PROG_TAG | name PROG_NAME }
       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 | devmap_hash | 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  maps,  otherwise list all maps currently loaded on the system.  In
                 case of name, MAP may match several maps which will all be shown.

                 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.  In case of name, MAP may  match  several  maps
                 which will all be dumped.

          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 freeze MAP
                 Freeze  the  map as read-only from user space. Entries from a frozen map can not
                 longer be updated or deleted with the bpf() system call. This operation  is  not
                 reversible, and the map remains immutable from user space until its destruction.
                 However, read  and  write  permissions  for  BPF  programs  to  the  map  remain
                 unchanged.

          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.

          -d, --debug
                 Print all logs available from libbpf, including debug-level information.

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(8)