€••:      Œsphinx.addnodes”Œdocument”“”)”}”(Œ	rawsource”Œ ”Œchildren”]”(Œtranslations”ŒLanguagesNode”“”)”}”(hhh]”(h Œpending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ
attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ	refdomain”Œstd”Œreftype”Œdoc”Œ	reftarget”Œ%/translations/zh_CN/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuŒtagname”hhhubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/zh_TW/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/it_IT/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ja_JP/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/ko_KR/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubh)”}”(hhh]”hŒSpanish”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ	refdomain”h)Œreftype”h+Œ	reftarget”Œ%/translations/sp_SP/bpf/bpf_licensing”Œmodname”NŒ	classname”NŒrefexplicit”ˆuh1hhhubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h
hhŒ	_document”hŒsource”NŒline”NubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒBPF licensing”h]”hŒBPF licensing”…””}”(hh¨hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh£hžhhŸŒ?/var/lib/git/docbuild/linux/Documentation/bpf/bpf_licensing.rst”h Kubh¢)”}”(hhh]”(h§)”}”(hŒ
Background”h]”hŒ
Background”…””}”(hhºhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hh·hžhhŸh¶h KubhŒbullet_list”“”)”}”(hhh]”hŒ	list_item”“”)”}”(hŒClassic BPF was BSD licensed
”h]”hŒ	paragraph”“”)”}”(hŒClassic BPF was BSD licensed”h]”hŒClassic BPF was BSD licensed”…””}”(hhÕhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KhhÏubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhÊhžhhŸh¶h Nubah}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ*”uh1hÈhŸh¶h Khh·hžhubhÔ)”}”(hŒý"BPF" was originally introduced as BSD Packet Filter in
http://www.tcpdump.org/papers/bpf-usenix93.pdf. The corresponding instruction
set and its implementation came from BSD with BSD license. That original
instruction set is now known as "classic BPF".”h]”(hŒ<â€œBPFâ€ was originally introduced as BSD Packet Filter in
”…””}”(hhñhžhhŸNh NubhŒ	reference”“”)”}”(hŒ.http://www.tcpdump.org/papers/bpf-usenix93.pdf”h]”hŒ.http://www.tcpdump.org/papers/bpf-usenix93.pdf”…””}”(hhûhžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”hýuh1hùhhñubhŒ›. The corresponding instruction
set and its implementation came from BSD with BSD license. That original
instruction set is now known as â€œclassic BPFâ€.”…””}”(hhñhžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K
hh·hžhubhÔ)”}”(hX  However an instruction set is a specification for machine-language interaction,
similar to a programming language.  It is not a code. Therefore, the
application of a BSD license may be misleading in a certain context, as the
instruction set may enjoy no copyright protection.”h]”hX  However an instruction set is a specification for machine-language interaction,
similar to a programming language.  It is not a code. Therefore, the
application of a BSD license may be misleading in a certain context, as the
instruction set may enjoy no copyright protection.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Khh·hžhubhÉ)”}”(hhh]”hÎ)”}”(hŒ8eBPF (extended BPF) instruction set continues to be BSD
”h]”hÔ)”}”(hŒ7eBPF (extended BPF) instruction set continues to be BSD”h]”hŒ7eBPF (extended BPF) instruction set continues to be BSD”…””}”(hj)  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Khj%  ubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj"  hžhhŸh¶h Nubah}”(h]”h ]”h"]”h$]”h&]”hïhðuh1hÈhŸh¶h Khh·hžhubhÔ)”}”(hŒÅIn 2014, the classic BPF instruction set was significantly extended. We
typically refer to this instruction set as eBPF to disambiguate it from cBPF.
The eBPF instruction set is still BSD licensed.”h]”hŒÅIn 2014, the classic BPF instruction set was significantly extended. We
typically refer to this instruction set as eBPF to disambiguate it from cBPF.
The eBPF instruction set is still BSD licensed.”…””}”(hjC  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h Khh·hžhubeh}”(h]”Œ
background”ah ]”h"]”Œ
background”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒImplementations of eBPF”h]”hŒImplementations of eBPF”…””}”(hj\  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjY  hžhhŸh¶h KubhÔ)”}”(hŒ^Using the eBPF instruction set requires implementing code in both kernel space
and user space.”h]”hŒ^Using the eBPF instruction set requires implementing code in both kernel space
and user space.”…””}”(hjj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KhjY  hžhubh¢)”}”(hhh]”(h§)”}”(hŒIn Linux Kernel”h]”hŒIn Linux Kernel”…””}”(hj{  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjx  hžhhŸh¶h K!ubhÔ)”}”(hX
  The reference implementations of the eBPF interpreter and various just-in-time
compilers are part of Linux and are GPLv2 licensed. The implementation of
eBPF helper functions is also GPLv2 licensed. Interpreters, JITs, helpers,
and verifiers are called eBPF runtime.”h]”hX
  The reference implementations of the eBPF interpreter and various just-in-time
compilers are part of Linux and are GPLv2 licensed. The implementation of
eBPF helper functions is also GPLv2 licensed. Interpreters, JITs, helpers,
and verifiers are called eBPF runtime.”…””}”(hj‰  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K#hjx  hžhubeh}”(h]”Œin-linux-kernel”ah ]”h"]”Œin linux kernel”ah$]”h&]”uh1h¡hjY  hžhhŸh¶h K!ubh¢)”}”(hhh]”(h§)”}”(hŒIn User Space”h]”hŒIn User Space”…””}”(hj¢  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjŸ  hžhhŸh¶h K)ubhÔ)”}”(hŒíThere are also implementations of eBPF runtime (interpreter, JITs, helper
functions) under
Apache2 (https://github.com/iovisor/ubpf),
MIT (https://github.com/qmonnet/rbpf), and
BSD (https://github.com/DPDK/dpdk/blob/main/lib/librte_bpf).”h]”(hŒdThere are also implementations of eBPF runtime (interpreter, JITs, helper
functions) under
Apache2 (”…””}”(hj°  hžhhŸNh Nubhú)”}”(hŒhttps://github.com/iovisor/ubpf”h]”hŒhttps://github.com/iovisor/ubpf”…””}”(hj¸  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jº  uh1hùhj°  ubhŒ),
MIT (”…””}”(hj°  hžhhŸNh Nubhú)”}”(hŒhttps://github.com/qmonnet/rbpf”h]”hŒhttps://github.com/qmonnet/rbpf”…””}”(hjË  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jÍ  uh1hùhj°  ubhŒ), and
BSD (”…””}”(hj°  hžhhŸNh Nubhú)”}”(hŒ5https://github.com/DPDK/dpdk/blob/main/lib/librte_bpf”h]”hŒ5https://github.com/DPDK/dpdk/blob/main/lib/librte_bpf”…””}”(hjÞ  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”jà  uh1hùhj°  ubhŒ).”…””}”(hj°  hžhhŸNh Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K+hjŸ  hžhubeh}”(h]”Œin-user-space”ah ]”h"]”Œin user space”ah$]”h&]”uh1h¡hjY  hžhhŸh¶h K)ubh¢)”}”(hhh]”(h§)”}”(hŒIn HW”h]”hŒIn HW”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjÿ  hžhhŸh¶h K2ubhÔ)”}”(hŒ™The HW can choose to execute eBPF instruction natively and provide eBPF runtime
in HW or via the use of implementing firmware with a proprietary license.”h]”hŒ™The HW can choose to execute eBPF instruction natively and provide eBPF runtime
in HW or via the use of implementing firmware with a proprietary license.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K4hjÿ  hžhubeh}”(h]”Œin-hw”ah ]”h"]”Œin hw”ah$]”h&]”uh1h¡hjY  hžhhŸh¶h K2ubh¢)”}”(hhh]”(h§)”}”(hŒIn other operating systems”h]”hŒIn other operating systems”…””}”(hj)  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj&  hžhhŸh¶h K8ubhÔ)”}”(hŒnOther kernels or user space implementations of eBPF instruction set and runtime
can have proprietary licenses.”h]”hŒnOther kernels or user space implementations of eBPF instruction set and runtime
can have proprietary licenses.”…””}”(hj7  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K:hj&  hžhubeh}”(h]”Œin-other-operating-systems”ah ]”h"]”Œin other operating systems”ah$]”h&]”uh1h¡hjY  hžhhŸh¶h K8ubeh}”(h]”Œimplementations-of-ebpf”ah ]”h"]”Œimplementations of ebpf”ah$]”h&]”uh1h¡hh£hžhhŸh¶h Kubh¢)”}”(hhh]”(h§)”}”(hŒ&Using BPF programs in the Linux kernel”h]”hŒ&Using BPF programs in the Linux kernel”…””}”(hjX  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hjU  hžhhŸh¶h K>ubhÔ)”}”(hŒˆLinux Kernel (while being GPLv2) allows linking of proprietary kernel modules
under these rules:
Documentation/process/license-rules.rst”h]”hŒˆLinux Kernel (while being GPLv2) allows linking of proprietary kernel modules
under these rules:
Documentation/process/license-rules.rst”…””}”(hjf  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h K@hjU  hžhubhÔ)”}”(hŒËWhen a kernel module is loaded, the linux kernel checks which functions it
intends to use. If any function is marked as "GPL only," the corresponding
module or program has to have GPL compatible license.”h]”hŒÏWhen a kernel module is loaded, the linux kernel checks which functions it
intends to use. If any function is marked as â€œGPL only,â€ the corresponding
module or program has to have GPL compatible license.”…””}”(hjt  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KDhjU  hžhubhÔ)”}”(hX;  Loading BPF program into the Linux kernel is similar to loading a kernel
module. BPF is loaded at run time and not statically linked to the Linux
kernel. BPF program loading follows the same license checking rules as kernel
modules. BPF programs can be proprietary if they don't use "GPL only" BPF
helper functions.”h]”hXA  Loading BPF program into the Linux kernel is similar to loading a kernel
module. BPF is loaded at run time and not statically linked to the Linux
kernel. BPF program loading follows the same license checking rules as kernel
modules. BPF programs can be proprietary if they donâ€™t use â€œGPL onlyâ€ BPF
helper functions.”…””}”(hj‚  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KHhjU  hžhubhÔ)”}”(hX9  Further, some BPF program types - Linux Security Modules (LSM) and TCP
Congestion Control (struct_ops), as of Aug 2021 - are required to be GPL
compatible even if they don't use "GPL only" helper functions directly. The
registration step of LSM and TCP congestion control modules of the Linux
kernel is done through EXPORT_SYMBOL_GPL kernel functions. In that sense LSM
and struct_ops BPF programs are implicitly calling "GPL only" functions.
The same restriction applies to BPF programs that call kernel functions
directly via unstable interface also known as "kfunc".”h]”hXG  Further, some BPF program types - Linux Security Modules (LSM) and TCP
Congestion Control (struct_ops), as of Aug 2021 - are required to be GPL
compatible even if they donâ€™t use â€œGPL onlyâ€ helper functions directly. The
registration step of LSM and TCP congestion control modules of the Linux
kernel is done through EXPORT_SYMBOL_GPL kernel functions. In that sense LSM
and struct_ops BPF programs are implicitly calling â€œGPL onlyâ€ functions.
The same restriction applies to BPF programs that call kernel functions
directly via unstable interface also known as â€œkfuncâ€.”…””}”(hj  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KNhjU  hžhubeh}”(h]”Œ&using-bpf-programs-in-the-linux-kernel”ah ]”h"]”Œ&using bpf programs in the linux kernel”ah$]”h&]”uh1h¡hh£hžhhŸh¶h K>ubh¢)”}”(hhh]”(h§)”}”(hŒ3Packaging BPF programs with user space applications”h]”hŒ3Packaging BPF programs with user space applications”…””}”(hj©  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1h¦hj¦  hžhhŸh¶h KXubhÔ)”}”(hŒåGenerally, proprietary-licensed applications and GPL licensed BPF programs
written for the Linux kernel in the same package can co-exist because they are
separate executable processes. This applies to both cBPF and eBPF programs.”h]”hŒåGenerally, proprietary-licensed applications and GPL licensed BPF programs
written for the Linux kernel in the same package can co-exist because they are
separate executable processes. This applies to both cBPF and eBPF programs.”…””}”(hj·  hžhhŸNh Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÓhŸh¶h KZhj¦  hžhubeh}”(h]”Œ3packaging-bpf-programs-with-user-space-applications”ah ]”h"]”Œ3packaging bpf programs with user space applications”ah$]”h&]”uh1h¡hh£hžhhŸh¶h KXubeh}”(h]”Œbpf-licensing”ah ]”h"]”Œbpf licensing”ah$]”h&]”uh1h¡hhhžhhŸh¶h Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”h¶uh1hŒcurrent_source”NŒcurrent_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(h¦NŒ	generator”NŒ	datestamp”NŒsource_link”NŒ
source_url”NŒtoc_backlinks”Œentry”Œfootnote_backlinks”KŒsectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒstrip_classes”NŒreport_level”KŒ
halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ	traceback”ˆŒinput_encoding”Œ	utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jø  Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œlanguage_code”Œen”Œrecord_dependencies”NŒconfig”NŒ	id_prefix”hŒauto_id_prefix”Œid”Œdump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”h¶Œ_destination”NŒ_config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒraw_enabled”KŒline_length_limit”M'Œpep_references”NŒpep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒrfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ	tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œsmart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œdocinfo_xform”KŒsectsubtitle_xform”‰Œimage_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jÒ  jÏ  jV  jS  jR  jO  jœ  j™  jü  jù  j#  j   jJ  jG  j£  j   jÊ  jÇ  uŒ	nametypes”}”(jÒ  ‰jV  ‰jR  ‰jœ  ‰jü  ‰j#  ‰jJ  ‰j£  ‰jÊ  ‰uh}”(jÏ  h£jS  h·jO  jY  j™  jx  jù  jŸ  j   jÿ  jG  j&  j   jU  jÇ  j¦  uŒfootnote_refs”}”Œcitation_refs”}”Œautofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ	footnotes”]”Œ	citations”]”Œautofootnote_start”KŒsymbol_footnote_start”K Œ
id_counter”Œcollections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œtransformer”NŒinclude_log”]”Œ
decoration”Nhžhub.