From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1ACBC433DF for ; Thu, 2 Jul 2020 11:05:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76FF320874 for ; Thu, 2 Jul 2020 11:05:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="HB18laux" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728332AbgGBLFM (ORCPT ); Thu, 2 Jul 2020 07:05:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728007AbgGBLFM (ORCPT ); Thu, 2 Jul 2020 07:05:12 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19BB3C08C5C1 for ; Thu, 2 Jul 2020 04:05:12 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id 95so13172483otw.10 for ; Thu, 02 Jul 2020 04:05:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=xEapiHe7NL0JaCbDs6xRgGHNuu1TpnlcFU0KZb4OXOM=; b=HB18lauxagRgqN51GzJR4AukvfExvfVv0djMwuyEnvMQ4tbtMmw5m48hx7El7RQFym D2gwDpBNWy//tRMELSVgsATIbxYRgb3nIGgKORvIQBkHmCTEHeDxcoII764vYkNaO/P7 +DltoFYkkTZ4UQao82kpRDY2QTWA9Boh+X8kQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xEapiHe7NL0JaCbDs6xRgGHNuu1TpnlcFU0KZb4OXOM=; b=IuuchnWs2IwViMniCtuwgbjm8rL4Lsh22n0rkGNLsAMkP0eaL/piaph8aU7TBzhUcl jAZZG00M0Tlz7vkEmulpRtZuQ8EekiBuO8tn6GDtot+RMIc6TxoO4XK/Vt2QhaqHFxNO VYhDDxer/TA1ch8cm/BMbl7rOMHPRAsL2QKOyNlZg61aE2XhB0AJ2vyas6JmwA3aYyYR ksdlet6K4AoVhq9AL/YSRy3UQayeiyWFhXbz/l+t7wtbsMqKu2lwDSuMOc15hXqiqyXq x0vXEystzpg1+MNdbXc3jSGQmMfRPssM8Nj74f5jap46U+ZAI4LxOjZBQB4gc7PtZy8I eWEg== X-Gm-Message-State: AOAM5301rbziBAIv94cc/UpdAD0Uifd5969/oYxJWJzQkgKzaLB+GUVF WcEdx/cZjS4mmIFlOj49Lt72xwjxGMazajnrVMfGcw== X-Google-Smtp-Source: ABdhPJzpgzWblQAh28N8sde+S3gyaMb2/DN2BWAGwZzTEAMbT/W869LMWgppyz0DZj9TvZKzsiiPSY8++AUQ/CZNxts= X-Received: by 2002:a9d:1c7:: with SMTP id e65mr24145594ote.147.1593687911173; Thu, 02 Jul 2020 04:05:11 -0700 (PDT) MIME-Version: 1.0 References: <20200702092416.11961-1-jakub@cloudflare.com> In-Reply-To: <20200702092416.11961-1-jakub@cloudflare.com> From: Lorenz Bauer Date: Thu, 2 Jul 2020 12:05:00 +0100 Message-ID: Subject: Re: [PATCH bpf-next v3 00/16] Run a BPF program on socket lookup To: Jakub Sitnicki Cc: bpf , Networking , kernel-team , Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Jakub Kicinski , Andrii Nakryiko , Marek Majkowski , Martin KaFai Lau Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 2 Jul 2020 at 10:24, Jakub Sitnicki wrote: > > Overview > ======== > > (Same as in v2. Please skip to next section if you've read it.) > > This series proposes a new BPF program type named BPF_PROG_TYPE_SK_LOOKUP, > or BPF sk_lookup for short. > > BPF sk_lookup program runs when transport layer is looking up a listening > socket for a new connection request (TCP), or when looking up an > unconnected socket for a packet (UDP). > > This serves as a mechanism to overcome the limits of what bind() API allows > to express. Two use-cases driving this work are: > > (1) steer packets destined to an IP range, fixed port to a single socket > > 192.0.2.0/24, port 80 -> NGINX socket > > (2) steer packets destined to an IP address, any port to a single socket > > 198.51.100.1, any port -> L7 proxy socket > > In its context, program receives information about the packet that > triggered the socket lookup. Namely IP version, L4 protocol identifier, and > address 4-tuple. > > To select a socket BPF program fetches it from a map holding socket > references, like SOCKMAP or SOCKHASH, calls bpf_sk_assign(ctx, sk, ...) > helper to record the selection, and returns BPF_REDIRECT code. Transport > layer then uses the selected socket as a result of socket lookup. > > Alternatively, program can also fail the lookup (BPF_DROP), or let the > lookup continue as usual (BPF_OK). > > This lets the user match packets with listening (TCP) or receiving (UDP) > sockets freely at the last possible point on the receive path, where we > know that packets are destined for local delivery after undergoing > policing, filtering, and routing. > > Program is attached to a network namespace, similar to BPF flow_dissector. > We add a new attach type, BPF_SK_LOOKUP, for this. > > Series structure > ================ > > Patches are organized as so: > > 1: enabled multiple link-based prog attachments for bpf-netns > 2: introduces sk_lookup program type > 3-4: hook up the program to run on ipv4/tcp socket lookup > 5-6: hook up the program to run on ipv6/tcp socket lookup > 7-8: hook up the program to run on ipv4/udp socket lookup > 9-10: hook up the program to run on ipv6/udp socket lookup > 11-13: libbpf & bpftool support for sk_lookup > 14-16: verifier and selftests for sk_lookup > > Patches are also available on GH: > > https://github.com/jsitnicki/linux/commits/bpf-inet-lookup-v3 > > Performance considerations > ========================== > > I'm re-running udp6 small packet flood test, the scenario for which we had > performance concerns in [v2], to measure pps hit after the changes called > out in change log below. > > Will follow up with results. But I'm posting the patches early for review > since there is a fair amount of code changes. > > Further work > ============ > > - user docs for new prog type, Documentation/bpf/prog_sk_lookup.rst > I'm looking for consensus on multi-prog semantics outlined in patch #4 > description before drafting the document. > > - timeout on accept() in tests > I need to extract a helper for it into network_helpers in > selftests/bpf/. Didn't want to make this series any longer. > > Note to maintainers > =================== > > This patch series depends on bpf-netns multi-prog changes that went > recently into 'bpf' [0]. It won't apply onto 'bpf-next' until 'bpf' gets > merged into 'bpf-next'. > > Changelog > ========= > > v3 brings the following changes based on feedback: > > 1. switch to link-based program attachment, > 2. support for multi-prog attachment, > 3. ability to skip reuseport socket selection, > 4. code on RX path is guarded by a static key, > 5. struct in6_addr's are no longer copied into BPF prog context, > 6. BPF prog context is initialized as late as possible. > > v2 -> v3: > - Changes called out in patches 1-2, 4, 6, 8, 10-14, 16 > - Patches dropped: > 01/17 flow_dissector: Extract attach/detach/query helpers > 03/17 inet: Store layer 4 protocol in inet_hashinfo > 08/17 udp: Store layer 4 protocol in udp_table > > v1 -> v2: > - Changes called out in patches 2, 13-15, 17 > - Rebase to recent bpf-next (b4563facdcae) > > RFCv2 -> v1: > > - Switch to fetching a socket from a map and selecting a socket with > bpf_sk_assign, instead of having a dedicated helper that does both. > - Run reuseport logic on sockets selected by BPF sk_lookup. > - Allow BPF sk_lookup to fail the lookup with no match. > - Go back to having just 2 hash table lookups in UDP. > > RFCv1 -> RFCv2: > > - Make socket lookup redirection map-based. BPF program now uses a > dedicated helper and a SOCKARRAY map to select the socket to redirect to. > A consequence of this change is that bpf_inet_lookup context is now > read-only. > - Look for connected UDP sockets before allowing redirection from BPF. > This makes connected UDP socket work as expected in the presence of > inet_lookup prog. > - Share the code for BPF_PROG_{ATTACH,DETACH,QUERY} with flow_dissector, > the only other per-netns BPF prog type. > > [RFCv1] https://lore.kernel.org/bpf/20190618130050.8344-1-jakub@cloudflare.com/ > [RFCv2] https://lore.kernel.org/bpf/20190828072250.29828-1-jakub@cloudflare.com/ > [v1] https://lore.kernel.org/bpf/20200511185218.1422406-18-jakub@cloudflare.com/ > [v2] https://lore.kernel.org/bpf/20200506125514.1020829-1-jakub@cloudflare.com/ > [0] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=951f38cf08350884e72e0936adf147a8d764cc5d > > Cc: Alexei Starovoitov > Cc: Andrii Nakryiko > Cc: Lorenz Bauer > Cc: Marek Majkowski > Cc: Martin KaFai Lau > > Jakub Sitnicki (16): > bpf, netns: Handle multiple link attachments > bpf: Introduce SK_LOOKUP program type with a dedicated attach point > inet: Extract helper for selecting socket from reuseport group > inet: Run SK_LOOKUP BPF program on socket lookup > inet6: Extract helper for selecting socket from reuseport group > inet6: Run SK_LOOKUP BPF program on socket lookup > udp: Extract helper for selecting socket from reuseport group > udp: Run SK_LOOKUP BPF program on socket lookup > udp6: Extract helper for selecting socket from reuseport group > udp6: Run SK_LOOKUP BPF program on socket lookup > bpf: Sync linux/bpf.h to tools/ > libbpf: Add support for SK_LOOKUP program type > tools/bpftool: Add name mappings for SK_LOOKUP prog and attach type > selftests/bpf: Add verifier tests for bpf_sk_lookup context access > selftests/bpf: Rename test_sk_lookup_kern.c to test_ref_track_kern.c > selftests/bpf: Tests for BPF_SK_LOOKUP attach point For the series: Reviewed-by: Lorenz Bauer > > include/linux/bpf-netns.h | 3 + > include/linux/bpf.h | 33 + > include/linux/bpf_types.h | 2 + > include/linux/filter.h | 99 ++ > include/uapi/linux/bpf.h | 74 + > kernel/bpf/core.c | 22 + > kernel/bpf/net_namespace.c | 125 +- > kernel/bpf/syscall.c | 9 + > net/core/filter.c | 188 +++ > net/ipv4/inet_hashtables.c | 60 +- > net/ipv4/udp.c | 93 +- > net/ipv6/inet6_hashtables.c | 66 +- > net/ipv6/udp.c | 97 +- > scripts/bpf_helpers_doc.py | 9 +- > tools/bpf/bpftool/common.c | 1 + > tools/bpf/bpftool/prog.c | 3 +- > tools/include/uapi/linux/bpf.h | 74 + > tools/lib/bpf/libbpf.c | 3 + > tools/lib/bpf/libbpf.h | 2 + > tools/lib/bpf/libbpf.map | 2 + > tools/lib/bpf/libbpf_probes.c | 3 + > .../bpf/prog_tests/reference_tracking.c | 2 +- > .../selftests/bpf/prog_tests/sk_lookup.c | 1353 +++++++++++++++++ > .../selftests/bpf/progs/test_ref_track_kern.c | 181 +++ > .../selftests/bpf/progs/test_sk_lookup_kern.c | 462 ++++-- > .../selftests/bpf/verifier/ctx_sk_lookup.c | 219 +++ > 26 files changed, 2995 insertions(+), 190 deletions(-) > create mode 100644 tools/testing/selftests/bpf/prog_tests/sk_lookup.c > create mode 100644 tools/testing/selftests/bpf/progs/test_ref_track_kern.c > create mode 100644 tools/testing/selftests/bpf/verifier/ctx_sk_lookup.c > > -- > 2.25.4 > -- Lorenz Bauer | Systems Engineer 6th Floor, County Hall/The Riverside Building, SE1 7PB, UK www.cloudflare.com