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