From patchwork Mon Jul 13 17:46:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 1328350 X-Patchwork-Delegate: bpf@iogearbox.net 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=tetYQPuo; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B5B1G4g3kz9sSd for ; Tue, 14 Jul 2020 03:47:14 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730466AbgGMRrO (ORCPT ); Mon, 13 Jul 2020 13:47:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730423AbgGMRrM (ORCPT ); Mon, 13 Jul 2020 13:47:12 -0400 Received: from mail-lf1-x144.google.com (mail-lf1-x144.google.com [IPv6:2a00:1450:4864:20::144]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E50BC061755 for ; Mon, 13 Jul 2020 10:47:12 -0700 (PDT) Received: by mail-lf1-x144.google.com with SMTP id s16so9556947lfp.12 for ; Mon, 13 Jul 2020 10:47:12 -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=4adtaF+vh9ZCjhGrf1+RjNro+KhZMebp2/WL08RlLtc=; b=tetYQPuo1HNfbQu7YB33sGi0dcbFBATg/HeznsxFxVoA92dczroFy75rMBQv6SPA69 DNRrA9E4KjSH8CDQP+/fghtq9rWIoRcehmYOs3JDLgee6cQuS52b8K8R+64WU3LsAQ1g 2AhOVjbta5jKnsaj9fyifypGgKb+WDYZKFhZQ= 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=4adtaF+vh9ZCjhGrf1+RjNro+KhZMebp2/WL08RlLtc=; b=eieYPaghYYXmthAhFettNLcxQfx4IRokJt/AFgC35x9ctdlF444yq24VTYlMjtQC1m Q1bcBW7obdkGHJKIDEbydij4D4cI0F9sxoznf4kswhtIB2Aur4w29eXDZVsRvOzFiYKZ vmROZz0dyunQW7vT3M9Hg0Mmdu91qtcXn2chm3OiwicfVtTtYWgckrbNhkrKLZ5P2SRM afvWFZQyu6QPQ/6VMl17MXo621tZQORiLYfH9VsJLnOWPa0G2gLJstJt3fcsF27Vlwvp FK99Ag6htHd0vwKp4Ja31pm4zu9qJrjuGRxjo2VaywQXIUDdXfRXzjRAt2wTDWbmLaWE ghMA== X-Gm-Message-State: AOAM530Dmw1I6+wHzhltxtikn4RmXQImLBU463ZMU3bOGcbkGXh33xMm bAOeYcLe/0XzWyZNyb3f7HqWIw== X-Google-Smtp-Source: ABdhPJyj9c5rR9UY+ckpPyOhrZ39eULC/Cyi0TZxxCaOU5hZjpnCZ9safKIrK4XOPvb9HIneCZk5Ng== X-Received: by 2002:a19:22d6:: with SMTP id i205mr175738lfi.50.1594662430546; Mon, 13 Jul 2020 10:47:10 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id a17sm4771942lfo.73.2020.07.13.10.47.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 10:47:09 -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 Subject: [PATCH bpf-next v4 08/16] udp: Run SK_LOOKUP BPF program on socket lookup Date: Mon, 13 Jul 2020 19:46:46 +0200 Message-Id: <20200713174654.642628-9-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200713174654.642628-1-jakub@cloudflare.com> References: <20200713174654.642628-1-jakub@cloudflare.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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 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 0d03e0277263..e82db3ab49d3 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;