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.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
============
bpftool-iter
============
-------------------------------------------------------------------------------
tool to create BPF iterators
-------------------------------------------------------------------------------
:Manual section: 8
.. include:: substitutions.rst
SYNOPSIS
========
**bpftool** [*OPTIONS*] **iter** *COMMAND*
*OPTIONS* := { |COMMON_OPTIONS| }
*COMMANDS* := { **pin** | **help** }
ITER COMMANDS
=============
| **bpftool** **iter pin** *OBJ* *PATH* [**map** *MAP*]
| **bpftool** **iter help**
|
| *OBJ* := /a/file/of/bpf_iter_target.o
| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
DESCRIPTION
===========
bpftool iter pin *OBJ* *PATH* [map *MAP*]
A bpf iterator combines a kernel iterating of particular kernel data (e.g.,
tasks, bpf_maps, etc.) and a bpf program called for each kernel data object
(e.g., one task, one bpf_map, etc.). User space can *read* kernel iterator
output through *read()* syscall.
The *pin* command creates a bpf iterator from *OBJ*, and pin it to *PATH*.
The *PATH* should be located in *bpffs* mount. It must not contain a dot
character ('.'), which is reserved for future extensions of *bpffs*.
Map element bpf iterator requires an additional parameter *MAP* so bpf
program can iterate over map elements for that map. User can have a bpf
program in kernel to run with each map element, do checking, filtering,
aggregation, etc. without copying data to user space.
User can then *cat PATH* to see the bpf iterator output.
bpftool iter help
Print short help message.
OPTIONS
=======
.. include:: common_options.rst
EXAMPLES
========
**# bpftool iter pin bpf_iter_netlink.o /sys/fs/bpf/my_netlink**
::
Create a file-based bpf iterator from bpf_iter_netlink.o and pin it
to /sys/fs/bpf/my_netlink
**# bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20**
::
Create a file-based bpf iterator from bpf_iter_hashmap.o and map with
id 20, and pin it to /sys/fs/bpf/my_hashmap
|
