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All bpftool commands support the options for JSON output and debug from libbpf. In addition, some commands support additional options corresponding to specific use cases. The list of options described in the man pages for the different commands are not always accurate. The messages for interactive help are mostly limited to HELP_SPEC_OPTIONS, and are even less representative of the actual set of options supported for the commands. Let's update the lists: - HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON and debug), and to be extensible (no ending curly bracket). - All commands use HELP_SPEC_OPTIONS in their help message, and then complete the list with their specific options. - The lists of options in the man pages are updated. - The formatting of the list for bpftool.rst is adjusted to match formatting for the other man pages. This is for consistency, and also because it will be helpful in a future patch to automatically check that the files are synchronised. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com
72 lines
2.1 KiB
ReStructuredText
72 lines
2.1 KiB
ReStructuredText
============
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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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SYNOPSIS
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========
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**bpftool** [*OPTIONS*] **iter** *COMMAND*
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*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } }
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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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