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1.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2
3============
4bpftool-iter
5============
6-------------------------------------------------------------------------------
7tool to create BPF iterators
8-------------------------------------------------------------------------------
9
10:Manual section: 8
11
12.. include:: substitutions.rst
13
14SYNOPSIS
15========
16
17**bpftool** [*OPTIONS*] **iter** *COMMAND*
18
19*OPTIONS* := { |COMMON_OPTIONS| }
20
21*COMMANDS* := { **pin** | **help** }
22
23ITER COMMANDS
24=============
25
26| **bpftool** **iter pin** *OBJ* *PATH* [**map** *MAP*]
27| **bpftool** **iter help**
28|
29| *OBJ* := /a/file/of/bpf_iter_target.o
30| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
31
32DESCRIPTION
33===========
34bpftool iter pin *OBJ* *PATH* [map *MAP*]
35 A bpf iterator combines a kernel iterating of particular kernel data (e.g.,
36 tasks, bpf_maps, etc.) and a bpf program called for each kernel data object
37 (e.g., one task, one bpf_map, etc.). User space can *read* kernel iterator
38 output through *read()* syscall.
39
40 The *pin* command creates a bpf iterator from *OBJ*, and pin it to *PATH*.
41 The *PATH* should be located in *bpffs* mount. It must not contain a dot
42 character ('.'), which is reserved for future extensions of *bpffs*.
43
44 Map element bpf iterator requires an additional parameter *MAP* so bpf
45 program can iterate over map elements for that map. User can have a bpf
46 program in kernel to run with each map element, do checking, filtering,
47 aggregation, etc. without copying data to user space.
48
49 User can then *cat PATH* to see the bpf iterator output.
50
51bpftool iter help
52 Print short help message.
53
54OPTIONS
55=======
56.. include:: common_options.rst
57
58EXAMPLES
59========
60**# bpftool iter pin bpf_iter_netlink.o /sys/fs/bpf/my_netlink**
61
62::
63
64 Create a file-based bpf iterator from bpf_iter_netlink.o and pin it
65 to /sys/fs/bpf/my_netlink
66
67**# bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20**
68
69::
70
71 Create a file-based bpf iterator from bpf_iter_hashmap.o and map with
72 id 20, and pin it to /sys/fs/bpf/my_hashmap
1.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2
3============
4bpftool-iter
5============
6-------------------------------------------------------------------------------
7tool to create BPF iterators
8-------------------------------------------------------------------------------
9
10:Manual section: 8
11
12.. include:: substitutions.rst
13
14SYNOPSIS
15========
16
17 **bpftool** [*OPTIONS*] **iter** *COMMAND*
18
19 *OPTIONS* := { |COMMON_OPTIONS| }
20
21 *COMMANDS* := { **pin** | **help** }
22
23ITER COMMANDS
24===================
25
26| **bpftool** **iter pin** *OBJ* *PATH* [**map** *MAP*]
27| **bpftool** **iter help**
28|
29| *OBJ* := /a/file/of/bpf_iter_target.o
30| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
31
32DESCRIPTION
33===========
34 **bpftool iter pin** *OBJ* *PATH* [**map** *MAP*]
35 A bpf iterator combines a kernel iterating of
36 particular kernel data (e.g., tasks, bpf_maps, etc.)
37 and a bpf program called for each kernel data object
38 (e.g., one task, one bpf_map, etc.). User space can
39 *read* kernel iterator output through *read()* syscall.
40
41 The *pin* command creates a bpf iterator from *OBJ*,
42 and pin it to *PATH*. The *PATH* should be located
43 in *bpffs* mount. It must not contain a dot
44 character ('.'), which is reserved for future extensions
45 of *bpffs*.
46
47 Map element bpf iterator requires an additional parameter
48 *MAP* so bpf program can iterate over map elements for
49 that map. User can have a bpf program in kernel to run
50 with each map element, do checking, filtering, aggregation,
51 etc. without copying data to user space.
52
53 User can then *cat PATH* to see the bpf iterator output.
54
55 **bpftool iter help**
56 Print short help message.
57
58OPTIONS
59=======
60 .. include:: common_options.rst
61
62EXAMPLES
63========
64**# bpftool iter pin bpf_iter_netlink.o /sys/fs/bpf/my_netlink**
65
66::
67
68 Create a file-based bpf iterator from bpf_iter_netlink.o and pin it
69 to /sys/fs/bpf/my_netlink
70
71**# bpftool iter pin bpf_iter_hashmap.o /sys/fs/bpf/my_hashmap map id 20**
72
73::
74
75 Create a file-based bpf iterator from bpf_iter_hashmap.o and map with
76 id 20, and pin it to /sys/fs/bpf/my_hashmap