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* Revert "xsk: Document ability to redirect to any socket bound to the same umem"Magnus Karlsson9 days1-19/+14
| | | | | | | | | | This reverts commit 968595a93669b6b4f6d1fcf80cf2d97956b6868f. Reported-by: Yuval El-Hanany <YuvalE@radware.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/xdp-newbies/8100DBDC-0B7C-49DB-9995-6027F6E63147@radware.com Link: https://lore.kernel.org/bpf/20240604122927.29080-3-magnus.karlsson@gmail.com
* xsk: document ability to redirect to any socket bound to the same umemMagnus Karlsson2024-02-051-14/+19
| | | | | | | | Document the ability to redirect to any socket bound to the same umem. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/r/20240205123553.22180-3-magnus.karlsson@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: add multi-buffer documentationMagnus Karlsson2023-07-191-1/+210
| | | | | | | | | Add AF_XDP multi-buffer support documentation including two pseudo-code samples. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/r/20230719132421.584801-18-maciej.fijalkowski@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* xsk: Honor SO_BINDTODEVICE on bindIlya Maximets2023-07-041-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Initial creation of an AF_XDP socket requires CAP_NET_RAW capability. A privileged process might create the socket and pass it to a non-privileged process for later use. However, that process will be able to bind the socket to any network interface. Even though it will not be able to receive any traffic without modification of the BPF map, the situation is not ideal. Sockets already have a mechanism that can be used to restrict what interface they can be attached to. That is SO_BINDTODEVICE. To change the SO_BINDTODEVICE binding the process will need CAP_NET_RAW. Make xsk_bind() honor the SO_BINDTODEVICE in order to allow safer workflow when non-privileged process is using AF_XDP. The intended workflow is following: 1. First process creates a bare socket with socket(AF_XDP, ...). 2. First process loads the XSK program to the interface. 3. First process adds the socket fd to a BPF map. 4. First process ties socket fd to a particular interface using SO_BINDTODEVICE. 5. First process sends socket fd to a second process. 6. Second process allocates UMEM. 7. Second process binds socket to the interface with bind(...). 8. Second process sends/receives the traffic. All the steps above are possible today if the first process is privileged and the second one has sufficient RLIMIT_MEMLOCK and no capabilities. However, the second process will be able to bind the socket to any interface it wants on step 7 and send traffic from it. With the proposed change, the second process will be able to bind the socket only to a specific interface chosen by the first process at step 4. Fixes: 965a99098443 ("xsk: add support for bind for Rx") Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/bpf/20230703175329.3259672-1-i.maximets@ovn.org
* Documentation: networking: correct spellingRandy Dunlap2023-01-311-2/+2
| | | | | | | | | | | | | | | | | Correct spelling problems for Documentation/networking/ as reported by codespell. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Jiri Pirko <jiri@nvidia.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20230129231053.20863-5-rdunlap@infradead.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* doc, af_xdp: Fix bind flags option typoBaruch Siach2021-07-121-3/+3
| | | | | | | | | | Fix XDP_ZERO_COPY flag typo since it is actually named XDP_ZEROCOPY instead as per if_xdp.h uapi header. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/1656fdf94704e9e735df0f8b97667d8f26dd098b.1625550240.git.baruch@tkos.co.il
* docs, af_xdp: Consistent indentation in examplesIlya Maximets2021-06-231-16/+16
| | | | | | | | | | | Examples in this document use all kinds of indentation from 3 to 5 spaces and even mixed with tabs. Making them all even and equal to 4 spaces. Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Link: https://lore.kernel.org/bpf/20210622185647.3705104-1-i.maximets@ovn.org
* xsk: Documentation for XDP_SHARED_UMEM between queues and netdevsMagnus Karlsson2020-08-311-10/+58
| | | | | | | | | | Add documentation for the XDP_SHARED_UMEM feature when a UMEM is shared between different queues and/or netdevs. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Link: https://lore.kernel.org/bpf/1598603189-32145-16-git-send-email-magnus.karlsson@intel.com
* xsk: Extend documentation for Rx|Tx-only sockets and shared umemsMagnus Karlsson2019-11-101-5/+23
| | | | | | | | | | | | | Add more documentation about the new Rx-only and Tx-only sockets in libbpf and also how libbpf can now support shared umems. Also found two pieces that could be improved in the text, that got fixed in this commit. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: William Tu <u9012063@gmail.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/bpf/1573148860-30254-6-git-send-email-magnus.karlsson@intel.com
* xsk: Improve documentation for AF_XDPMagnus Karlsson2019-10-231-28/+231
| | | | | | | | | | | | | | | | | | Added sections on all the bind flags, libbpf, all the setsockopts and all the getsockopts. Also updated the document to reflect the latest features and to correct some spelling errors. v1 -> v2: * Updated XDP program with latest BTF map format * Added one more FAQ entry * Some minor edits and corrections v2 -> v3: * Simplified XDP_SHARED_UMEM example XDP program Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/1571648224-16889-1-git-send-email-magnus.karlsson@intel.com
* doc/af_xdp: include unaligned chunk caseKevin Laatz2019-08-311-4/+6
| | | | | | | | | | | | The addition of unaligned chunks mode, the documentation needs to be updated to indicate that the incoming addr to the fill ring will only be masked if the user application is run in the aligned chunk mode. This patch also adds a line to explicitly indicate that the incoming addr will not be masked if running the user application in the unaligned chunk mode. Signed-off-by: Kevin Laatz <kevin.laatz@intel.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: sample kernel code is now in libbpfEric Leblond2019-06-241-1/+15
| | | | | | | | | | Fix documentation that mention xdpsock_kern.c which has been replaced by code embedded in libbpf. Signed-off-by: Eric Leblond <eric@regit.org> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Documentation/networking: fix af_xdp.rst Sphinx warningsRandy Dunlap2019-05-211-4/+4
| | | | | | | | | | | | | | | | Fix Sphinx warnings in Documentation/networking/af_xdp.rst by adding indentation: Documentation/networking/af_xdp.rst:319: WARNING: Literal block expected; none found. Documentation/networking/af_xdp.rst:326: WARNING: Literal block expected; none found. Fixes: 0f4a9b7d4ecb ("xsk: add FAQ to facilitate for first time users") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Magnus Karlsson <magnus.karlsson@intel.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: add FAQ to facilitate for first time usersMagnus Karlsson2019-02-251-1/+35
| | | | | | | | | Added an FAQ section in Documentation/networking/af_xdp.rst to help first time users with common problems. As problems are getting identified, entries will be added to the FAQ. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* bpf: typo fix in Documentation/networking/af_xdp.rstKonrad Djimeli2018-10-051-2/+2
| | | | | | | | Fix a simple typo: Completetion -> Completion Signed-off-by: Konrad Djimeli <kdjimeli@igalia.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* xsk: new descriptor addressing schemeBjörn Töpel2018-06-041-43/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, AF_XDP only supports a fixed frame-size memory scheme where each frame is referenced via an index (idx). A user passes the frame index to the kernel, and the kernel acts upon the data. Some NICs, however, do not have a fixed frame-size model, instead they have a model where a memory window is passed to the hardware and multiple frames are filled into that window (referred to as the "type-writer" model). By changing the descriptor format from the current frame index addressing scheme, AF_XDP can in the future be extended to support these kinds of NICs. In the index-based model, an idx refers to a frame of size frame_size. Addressing a frame in the UMEM is done by offseting the UMEM starting address by a global offset, idx * frame_size + offset. Communicating via the fill- and completion-rings are done by means of idx. In this commit, the idx is removed in favor of an address (addr), which is a relative address ranging over the UMEM. To convert an idx-based address to the new addr is simply: addr = idx * frame_size + offset. We also stop referring to the UMEM "frame" as a frame. Instead it is simply called a chunk. To transfer ownership of a chunk to the kernel, the addr of the chunk is passed in the fill-ring. Note, that the kernel will mask addr to make it chunk aligned, so there is no need for userspace to do that. E.g., for a chunk size of 2k, passing an addr of 2048, 2050 or 3000 to the fill-ring will refer to the same chunk. On the completion-ring, the addr will match that of the Tx descriptor, passed to the kernel. Changing the descriptor format to use chunks/addr will allow for future changes to move to a type-writer based model, where multiple frames can reside in one chunk. In this model passing one single chunk into the fill-ring, would potentially result in multiple Rx descriptors. This commit changes the uapi of AF_XDP sockets, and updates the documentation. Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* samples/bpf: sample application and documentation for AF_XDP socketsMagnus Karlsson2018-05-031-0/+297
This is a sample application for AF_XDP sockets. The application supports three different modes of operation: rxdrop, txonly and l2fwd. To show-case a simple round-robin load-balancing between a set of sockets in an xskmap, set the RR_LB compile time define option to 1 in "xdpsock.h". v2: The entries variable was calculated twice in {umem,xq}_nb_avail. Co-authored-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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