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=-10.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT 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 28633C4345B for ; Fri, 17 Jul 2020 10:36:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05C1620734 for ; Fri, 17 Jul 2020 10:36:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="De3AyfdB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726635AbgGQKf4 (ORCPT ); Fri, 17 Jul 2020 06:35:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726411AbgGQKfz (ORCPT ); Fri, 17 Jul 2020 06:35:55 -0400 Received: from mail-lj1-x241.google.com (mail-lj1-x241.google.com [IPv6:2a00:1450:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AEACDC08C5DD for ; Fri, 17 Jul 2020 03:35:52 -0700 (PDT) Received: by mail-lj1-x241.google.com with SMTP id q4so12106218lji.2 for ; Fri, 17 Jul 2020 03:35:52 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=LPXPoxj9sk9RYPwMSCYR+PV+oV7CMuYMBBVgyyAlEyA=; b=De3AyfdBCd/kNvQAqMJMWG87C6e15az2OmmYDIXUUhfKw4ciqCBK+ymMzPynLRjM9r b0167rWcKYHLJm+8IEa4nJEC03I2uEfDrD4eqVz99ENqsH/Vy0VBTxQLS7RjvMvDo90+ yLG5S4zfIccWOlswBNgMVnmCDJab7qZL6YLXU= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=LPXPoxj9sk9RYPwMSCYR+PV+oV7CMuYMBBVgyyAlEyA=; b=kh2NhSw19ZaK8nazg7292vch/I33cYX04vnOVar/C9gVH96zWNqW79Mb/mbePUwXm6 gi4PMuUZMARk33pJACRrF/atr1HNnry/loonOXn/f5ORwKuHIeGWF8wMc7ohADMpwevt Z9WxGorhDchMw7fGAjq3Dh/l78G+Of5aqmPethuYgeBqhnANFHxxPYw2DQDePOx1rcgH xPVeuLRJnvLHmvSSuJ/FoGbh3Hdj/jVqSwg8IzYr1YqO/h6ngQCRmkQOngIxCR2zIace 2378WMoT4Uf9ZaOIEpRuYFc1G/799TV/+o8GADPSf0VXpZgUn6KtVsyAp5mh5HrsE2ag EVNg== X-Gm-Message-State: AOAM532MdhY/WPSPMQUF449/JKRGsMlO1IUCr2hY3h0Yu9fhb5ORvcyV 4SKbChNYh9xyZjl8M+Ty/bXR6MsqEJZYVg== X-Google-Smtp-Source: ABdhPJy717iY5PK3LFbNDSGyiScNSrygHzIIL4465sTOE6iOtptBculw2TIerX7iQXcEsO0nZYHx8A== X-Received: by 2002:a05:651c:305:: with SMTP id a5mr4011098ljp.387.1594982150831; Fri, 17 Jul 2020 03:35:50 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id 193sm2122534lfa.90.2020.07.17.03.35.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jul 2020 03:35:50 -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 , Marek Majkowski , Andrii Nakryiko Subject: [PATCH bpf-next v5 08/15] udp: Run SK_LOOKUP BPF program on socket lookup Date: Fri, 17 Jul 2020 12:35:29 +0200 Message-Id: <20200717103536.397595-9-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200717103536.397595-1-jakub@cloudflare.com> References: <20200717103536.397595-1-jakub@cloudflare.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Following INET/TCP socket lookup changes, modify UDP socket lookup to let BPF program select a receiving socket before searching for a socket by destination address and port as usual. Lookup of connected sockets that match packet 4-tuple is unaffected by this change. BPF program runs, and potentially overrides the lookup result, only if a 4-tuple match was not found. Suggested-by: Marek Majkowski Acked-by: Andrii Nakryiko Signed-off-by: Jakub Sitnicki --- Notes: v4: - Adapt to change in bpf_sk_lookup_run_v4 return value semantics. v3: - Use a static_key to minimize the hook overhead when not used. (Alexei) - Adapt for running an array of attached programs. (Alexei) - Adapt for optionally skipping reuseport selection. (Martin) net/ipv4/udp.c | 59 ++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 50 insertions(+), 9 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 9296faea3acf..b738c63d7a77 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -456,6 +456,29 @@ static struct sock *udp4_lib_lookup2(struct net *net, return result; } +static inline struct sock *udp4_lookup_run_bpf(struct net *net, + struct udp_table *udptable, + struct sk_buff *skb, + __be32 saddr, __be16 sport, + __be32 daddr, u16 hnum) +{ + struct sock *sk, *reuse_sk; + bool no_reuseport; + + if (udptable != &udp_table) + return NULL; /* only UDP is supported */ + + no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, + saddr, sport, daddr, hnum, &sk); + if (no_reuseport || IS_ERR_OR_NULL(sk)) + return sk; + + reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (reuse_sk) + sk = reuse_sk; + return sk; +} + /* UDP is nearly always wildcards out the wazoo, it makes no sense to try * harder than this. -DaveM */ @@ -463,27 +486,45 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, __be32 daddr, __be16 dport, int dif, int sdif, struct udp_table *udptable, struct sk_buff *skb) { - struct sock *result; unsigned short hnum = ntohs(dport); unsigned int hash2, slot2; struct udp_hslot *hslot2; + struct sock *result, *sk; hash2 = ipv4_portaddr_hash(net, daddr, hnum); slot2 = hash2 & udptable->mask; hslot2 = &udptable->hash2[slot2]; + /* Lookup connected or non-wildcard socket */ result = udp4_lib_lookup2(net, saddr, sport, daddr, hnum, dif, sdif, hslot2, skb); - if (!result) { - hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); - slot2 = hash2 & udptable->mask; - hslot2 = &udptable->hash2[slot2]; - - result = udp4_lib_lookup2(net, saddr, sport, - htonl(INADDR_ANY), hnum, dif, sdif, - hslot2, skb); + if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) + goto done; + + /* Lookup redirect from BPF */ + if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { + sk = udp4_lookup_run_bpf(net, udptable, skb, + saddr, sport, daddr, hnum); + if (sk) { + result = sk; + goto done; + } } + + /* Got non-wildcard socket or error on first lookup */ + if (result) + goto done; + + /* Lookup wildcard sockets */ + hash2 = ipv4_portaddr_hash(net, htonl(INADDR_ANY), hnum); + slot2 = hash2 & udptable->mask; + hslot2 = &udptable->hash2[slot2]; + + result = udp4_lib_lookup2(net, saddr, sport, + htonl(INADDR_ANY), hnum, dif, sdif, + hslot2, skb); +done: if (IS_ERR(result)) return NULL; return result; -- 2.25.4