Commit Graph

26 Commits

Author SHA1 Message Date
Toke Høiland-Jørgensen 1a7551f150 Documentation/bpf: Add documentation for BPF_PROG_RUN
This adds documentation for the BPF_PROG_RUN command; a short overview of
the command itself, and a more verbose description of the "live packet"
mode for XDP introduced in the previous commit.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220309105346.100053-3-toke@redhat.com
2022-03-09 14:19:22 -08:00
Christoph Hellwig 41db511a3a bpf, docs: Split the comparism to classic BPF from instruction-set.rst
Split the introductory that explain eBPF vs classic BPF and how it maps
to hardware from the instruction set specification into a standalone
document.  This duplicates a little bit of information but gives us a
useful reference for the eBPF instrution set that is not encumbered by
classic BPF.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211223101906.977624-3-hch@lst.de
2021-12-30 16:31:44 -08:00
Christoph Hellwig 88691e9e1e bpf, docs: Split general purpose eBPF documentation out of filter.rst
filter.rst starts out documenting the classic BPF and then spills into
introducing and documentating eBPF.  Move the eBPF documentation into
rwo new files under Documentation/bpf/ for the instruction set and
the verifier and link to the BPF documentation from filter.rst.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211119163215.971383-6-hch@lst.de
2021-11-30 10:52:11 -08:00
Dave Tucker 5931d9a3d0 bpf, docs: Fix ordering of bpf documentation
This commit fixes the display of the BPF documentation in the sidebar
when rendered as HTML.

Before this patch, the sidebar would render as follows for some
sections:

| BPF Documentation
  |- BPF Type Format (BTF)
    |- BPF Type Format (BTF)

This was due to creating a heading in index.rst followed by
a sphinx toctree, where the file referenced carries the same
title as the section heading.

To fix this I applied a pattern that has been established in other
subfolders of Documentation:

1. Re-wrote index.rst to have a single toctree
2. Split the sections out in to their own files

Additionally maps.rst and programs.rst make use of a glob pattern to
include map_* or prog_* rst files in their toctree, meaning future map
or program type documentation will be automatically included.

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1a1eed800e7b9dc13b458de113a489641519b0cc.1636749493.git.dave@dtucker.co.uk
2021-11-17 23:24:01 +01:00
Alexei Starovoitov c86216bc96 bpf: Document BPF licensing.
Document and clarify BPF licensing.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Joe Stringer <joe@cilium.io>
Acked-by: Lorenz Bauer <lmb@cloudflare.com>
Acked-by: Dave Thaler <dthaler@microsoft.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210917230034.51080-1-alexei.starovoitov@gmail.com
2021-09-22 23:13:13 +02:00
grantseltzer bb57164920 bpf: Reconfigure libbpf docs to remove unversioned API
This removes the libbpf_api.rst file from the kernel documentation.
The intention for this file was to pull documentation from comments
above API functions in libbpf. However, due to limitations of the
kernel documentation system, this API documentation could not be
versioned, which is counterintuative to how users expect to use it.
There is also currently no doc comments, making this a blank page.

Once the kernel comment documentation is actually contributed, it
will still exist in the kernel repository, just in the code itself.

A seperate site is being spun up to generate documentaiton from those
comments in a way in which it can be versioned properly.

This also reconfigures the bpf documentation index page to make it
easier to sync to the previously mentioned documentaiton site.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210810020508.280639-1-grantseltzer@gmail.com
2021-08-16 17:25:03 -07:00
Grant Seltzer f42cfb469f bpf: Add documentation for libbpf including API autogen
This patch is meant to start the initiative to document libbpf.
It includes .rst files which are text documentation describing building,
API naming convention, as well as an index to generated API documentation.

In this approach the generated API documentation is enabled by the kernels
existing kernel documentation system which uses sphinx. The resulting docs
would then be synced to kernel.org/doc

You can test this by running `make htmldocs` and serving the html in
Documentation/output. Since libbpf does not yet have comments in kernel
doc format, see kernel.org/doc/html/latest/doc-guide/kernel-doc.html for
an example so you can test this.

The advantage of this approach is to use the existing sphinx
infrastructure that the kernel has, and have libbpf docs in
the same place as everything else.

The current plan is to have the libbpf mirror sync the generated docs
and version them based on the libbpf releases which are cut on github.

This patch includes the addition of libbpf_api.rst which pulls comment
documentation from header files in libbpf under tools/lib/bpf/. The comment
docs would be of the standard kernel doc format.

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210618140459.9887-2-grantseltzer@gmail.com
2021-06-18 23:06:06 +02:00
Yonghong Song fc8c262e0e bpf, docs: Add llvm_reloc.rst to explain llvm bpf relocations
LLVM upstream commit https://reviews.llvm.org/D102712 made some changes
to bpf relocations to make them llvm linker lld friendly. The scope of
existing relocations R_BPF_64_{64,32} is narrowed and new relocations
R_BPF_64_{ABS32,ABS64,NODYLD32} are introduced.

Let us add some documentation about llvm bpf relocations so people can
understand how to resolve them properly in their respective tools.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210526152457.335210-1-yhs@fb.com
2021-05-28 22:12:04 +02:00
Joe Stringer 6197e5b7b1 docs/bpf: Add bpf() syscall command reference
Generate the syscall command reference from the UAPI header file and
include it in the main bpf docs page.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-15-joe@cilium.io
2021-03-04 18:39:46 -08:00
Jakub Sitnicki 07ff4f0126 bpf: sk_lookup: Add user documentation
Describe the purpose of BPF sk_lookup program, how it can be attached, when
it gets invoked, and what information gets passed to it. Point the reader
to examples and further documentation.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200821100226.403844-1-jakub@cloudflare.com
2020-08-24 14:46:50 -07:00
Joe Stringer a62f68c172 doc: Add link to bpf helpers man page
The bpf-helpers(7) man pages provide an invaluable description of the
functions that an eBPF program can call at runtime. Link them here.

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200813180807.2821735-1-joe@wand.net.nz
2020-08-13 22:48:06 +02:00
Linus Torvalds 47ec5303d7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan.

 2) Support UDP segmentation in code TSO code, from Eric Dumazet.

 3) Allow flashing different flash images in cxgb4 driver, from Vishal
    Kulkarni.

 4) Add drop frames counter and flow status to tc flower offloading,
    from Po Liu.

 5) Support n-tuple filters in cxgb4, from Vishal Kulkarni.

 6) Various new indirect call avoidance, from Eric Dumazet and Brian
    Vazquez.

 7) Fix BPF verifier failures on 32-bit pointer arithmetic, from
    Yonghong Song.

 8) Support querying and setting hardware address of a port function via
    devlink, use this in mlx5, from Parav Pandit.

 9) Support hw ipsec offload on bonding slaves, from Jarod Wilson.

10) Switch qca8k driver over to phylink, from Jonathan McDowell.

11) In bpftool, show list of processes holding BPF FD references to
    maps, programs, links, and btf objects. From Andrii Nakryiko.

12) Several conversions over to generic power management, from Vaibhav
    Gupta.

13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry
    Yakunin.

14) Various https url conversions, from Alexander A. Klimov.

15) Timestamping and PHC support for mscc PHY driver, from Antoine
    Tenart.

16) Support bpf iterating over tcp and udp sockets, from Yonghong Song.

17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov.

18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan.

19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several
    drivers. From Luc Van Oostenryck.

20) XDP support for xen-netfront, from Denis Kirjanov.

21) Support receive buffer autotuning in MPTCP, from Florian Westphal.

22) Support EF100 chip in sfc driver, from Edward Cree.

23) Add XDP support to mvpp2 driver, from Matteo Croce.

24) Support MPTCP in sock_diag, from Paolo Abeni.

25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic
    infrastructure, from Jakub Kicinski.

26) Several pci_ --> dma_ API conversions, from Christophe JAILLET.

27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel.

28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki.

29) Refactor a lot of networking socket option handling code in order to
    avoid set_fs() calls, from Christoph Hellwig.

30) Add rfc4884 support to icmp code, from Willem de Bruijn.

31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei.

32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin.

33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin.

34) Support TCP syncookies in MPTCP, from Flowian Westphal.

35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano
    Brivio.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits)
  net: thunderx: initialize VF's mailbox mutex before first usage
  usb: hso: remove bogus check for EINPROGRESS
  usb: hso: no complaint about kmalloc failure
  hso: fix bailout in error case of probe
  ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM
  selftests/net: relax cpu affinity requirement in msg_zerocopy test
  mptcp: be careful on subflow creation
  selftests: rtnetlink: make kci_test_encap() return sub-test result
  selftests: rtnetlink: correct the final return value for the test
  net: dsa: sja1105: use detected device id instead of DT one on mismatch
  tipc: set ub->ifindex for local ipv6 address
  ipv6: add ipv6_dev_find()
  net: openvswitch: silence suspicious RCU usage warning
  Revert "vxlan: fix tos value before xmit"
  ptp: only allow phase values lower than 1 period
  farsync: switch from 'pci_' to 'dma_' API
  wan: wanxl: switch from 'pci_' to 'dma_' API
  hv_netvsc: do not use VF device if link is down
  dpaa2-eth: Fix passing zero to 'PTR_ERR' warning
  net: macb: Properly handle phylink on at91sam9x
  ...
2020-08-05 20:13:21 -07:00
Tiezhu Yang ffba964e4d Documentation/bpf: Use valid and new links in index.rst
There exists an error "404 Not Found" when I click the html link of
"Documentation/networking/filter.rst" in the BPF documentation [1],
fix it.

Additionally, use the new links about "BPF and XDP Reference Guide"
and "bpf(2)" to avoid redirects.

[1] https://www.kernel.org/doc/html/latest/bpf/

Fixes: d9b9170a26 ("docs: bpf: Rename README.rst to index.rst")
Fixes: cb3f0d56e1 ("docs: networking: convert filter.txt to ReST")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1596184142-18476-1-git-send-email-yangtiezhu@loongson.cn
2020-07-31 18:17:51 +02:00
YiFei Zhu 4e15f460be Documentation/bpf: Document CGROUP_STORAGE map type
The machanics and usage are not very straightforward. Given the
changes it's better to document how it works and how to use it,
rather than having to rely on the examples and implementation to
infer what is going on.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/b412edfbb05cb1077c9e2a36a981a54ee23fa8b3.1595565795.git.zhuyifei@google.com
2020-07-25 20:16:36 -07:00
Daniel W. S. Almeida 5fe52b3865 docs: bpf/index.rst: Add ringbuf.rst
Fix the following warning

Documentation/bpf/ringbuf.rst: WARNING: document isn't
included in any toctree

By adding it to the index.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20200718165107.625847-10-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-23 14:17:00 -06:00
Mauro Carvalho Chehab cb3f0d56e1 docs: networking: convert filter.txt to ReST
- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- use footnote markup;
- mark tables as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-28 14:39:46 -07:00
KP Singh 4dece7f3b9 bpf: lsm: Add Documentation
Document how eBPF programs (BPF_PROG_TYPE_LSM) can be loaded and
attached (BPF_LSM_MAC) to the LSM hooks.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Florent Revest <revest@google.com>
Reviewed-by: Thomas Garnier <thgarnie@google.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Link: https://lore.kernel.org/bpf/20200329004356.27286-9-kpsingh@chromium.org
2020-03-30 01:35:12 +02:00
Andrey Ignatov 8c061865f5 bpf: Document bpf_inspect drgn tool
It's a follow-up for discussion in [1].

drgn tool bpf_inspect.py was merged to drgn repo in [2]. Document it
in kernel tree to make BPF developers aware that the tool exists and
can help with getting BPF state unavailable via UAPI.

For now it's just one tool but the doc is written in a way that allows
to cover more tools in the future if needed.

Please refer to the doc itself for more details.

The patch was tested by `make htmldocs` and sanity-checking that
resulting html looks good.

v2 -> v3:
  - two sections: "Description" and "Getting started" (Daniel);
  - add examples in "Getting started" section (Daniel);
  - add "Customization" section to show how tool can be customized.

v1 -> v2:
  - better "BPF drgn tools" section (Alexei)

  [1] https://lore.kernel.org/bpf/20200228201514.GB51456@rdna-mbp/T/#mefed65e8a98116bd5d07d09a570a3eac46724951
  [2] https://github.com/osandov/drgn/pull/49

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200324185135.1431038-1-rdna@fb.com
2020-03-26 00:08:36 +01:00
Ilya Leoshkevich 7e07e7aec5 bpf: Add s390 testing documentation
This commits adds a document that explains how to test BPF in an s390
QEMU guest.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191029172916.36528-1-iii@linux.ibm.com
2019-10-30 16:25:31 +01:00
Stanislav Fomichev 0c51b3697a bpf: add sockopt documentation
Provide user documentation about sockopt prog type and cgroup hooks.

v9:
* add details about setsockopt context and inheritance

v7:
* add description for retval=0 and optlen=-1

v6:
* describe cgroup chaining, add example

v2:
* use return code 2 for kernel bypass

Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-06-27 15:25:17 -07:00
Stanislav Fomichev 8069594673 bpf: move BPF_PROG_TYPE_FLOW_DISSECTOR documentation to a new common place
In commit da70314917 ("bpf: Document BPF_PROG_TYPE_CGROUP_SYSCTL")
Andrey proposes to put per-prog type docs under Documentation/bpf/

Let's move flow dissector documentation there as well.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-18 16:59:42 -07:00
Andrey Ignatov da70314917 bpf: Document BPF_PROG_TYPE_CGROUP_SYSCTL
Add documentation for BPF_PROG_TYPE_CGROUP_SYSCTL, including general
info, attach type, context, return code, helpers, example and usage
considerations.

A separate file prog_cgroup_sysctl.rst is added to Documentation/bpf/.

In the future more program types can be documented in their own
prog_<name>.rst files.

Another way to place program type specific documentation would be to
group program types somehow (e.g. cgroup.rst for all cgroup-bpf
programs), but it may not scale well since some program types may belong
to different groups, e.g. BPF_PROG_TYPE_CGROUP_SKB can be documented
together with either cgroup-bpf programs or programs that access skb.

The new file is added to the index and verified by `make htmldocs` /
sanity-check by lynx.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-18 16:05:36 -07:00
Yonghong Song ffcf7ce933 bpf: btf: add btf documentation
This patch added documentation for BTF (BPF Debug Format).
The document is placed under linux:Documentation/bpf directory.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-22 23:50:02 -08:00
Tobin C. Harding 6919bcc8aa docs: bpf: Capitalise document heading
The majority of files in the kernel documentation index use
capitalisation for all words, especially the shorter ones.  BPF docs
better fit in with the rest of the documentation if the heading is all
capitalised.

Capitalise document heading.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:23:48 +02:00
Tobin C. Harding b3d40f63d2 docs: bpf: Add toctree to index
Recently bpf/ docs were converted to us RST format.  bp/index.rst was
created out of README but toctree was not added to include files within
Documentation/bpf/

Add toctree to Documentation/bpf/index.rst

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:23:48 +02:00
Tobin C. Harding d9b9170a26 docs: bpf: Rename README.rst to index.rst
Recently bpf/ docs were converted to use RST format.  'README.rst' was
created but in order to fit in with the Sphinx build system this file
should be named 'index.rst'.  Rename file, fixes to integrate into
Sphinx build system in following patches.

docs: Rename Documentation/bpf/README.rst to Documentation/bpf/index.rst

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:23:48 +02:00