From patchwork Thu Jul 2 09:24:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 1321176 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=cloudflare.com header.i=@cloudflare.com header.a=rsa-sha256 header.s=google header.b=QbS+tkAF; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49yCN54jK7z9sPF for ; Thu, 2 Jul 2020 19:24:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728009AbgGBJYU (ORCPT ); Thu, 2 Jul 2020 05:24:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726183AbgGBJYT (ORCPT ); Thu, 2 Jul 2020 05:24:19 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A04BC08C5C1 for ; Thu, 2 Jul 2020 02:24:19 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id y10so28450688eje.1 for ; Thu, 02 Jul 2020 02:24:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=d/9xPYZP4tLOP1W2+YlZxcJGdaiixZnhV8pfC4vwDAA=; b=QbS+tkAFAXuQTXOC4fE2+NS+XmgWM2jkwpfoFJvXXVMJ165Zt7/QrcN6zuxFepN8a/ Z3Tgyg02LyL2/daSiV1lTNV2P98V/DVSiw6RWLoGIpADB4wEjWrXUBbCjOHdvoNOW7sD wOfCdPTzR9lPTQWEbIQo5Id7TTPQefXFmUOjQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=d/9xPYZP4tLOP1W2+YlZxcJGdaiixZnhV8pfC4vwDAA=; b=EMlHMoMQhIIHA9iLIpY9LkooXPmAedhoXVJdsxX5lOCMWnlbUc+OZMOq7axiNFHG6+ kjMh2Pu1NGPq7fpTLyDjx26CjKHGv+YkZ3U9Gmgykwq4UhxST2EAbvJCynJBzWkl+Etj NaSkpNZDx/Jp8/qcsFoDH4hLs0qrD55iyBwg572klDDLl5MzF+7eZHCeiRGpZVtagewj mqQN7wr4ul6FLM5o+lhsUdC78DgO8VAMyfDcjzNToXJpm7dqSCMMju/DSWrESxYxg2X7 QvfnSrUJtIb2bNeJtlZy8n/GK76rIYIJiRFMl7C/uLI/zdZEeSKmMJDULI2grtcU7lOk ALbA== X-Gm-Message-State: AOAM530vRhcYpqFPIPS6mYgdoB9U+6U585C3sD0ZXYFHwzwoltwoq23L e11CoQwpkSRNaE2v4QHaMpYsbg== X-Google-Smtp-Source: ABdhPJxFJaSsmQI2MneR+jGl0ep3G5IO6L+X2SCsAZl8EajIIG0cFNhTPDox/CkBQmO8OmMmXZ6bWQ== X-Received: by 2002:a17:907:94cf:: with SMTP id dn15mr28754396ejc.457.1593681857991; Thu, 02 Jul 2020 02:24:17 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id d26sm6489054ejw.89.2020.07.02.02.24.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 02:24:17 -0700 (PDT) From: Jakub Sitnicki To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com, Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Jakub Kicinski , Andrii Nakryiko , Lorenz Bauer , Marek Majkowski , Martin KaFai Lau Subject: [PATCH bpf-next v3 00/16] Run a BPF program on socket lookup Date: Thu, 2 Jul 2020 11:24:00 +0200 Message-Id: <20200702092416.11961-1-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 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 Reviewed-by: Lorenz Bauer