From patchwork Thu Jul 2 09:24:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 1321190 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.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=bpf-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=xAxCWfIL; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49yCNR3kyVz9sPF for ; Thu, 2 Jul 2020 19:24:39 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728309AbgGBJYi (ORCPT ); Thu, 2 Jul 2020 05:24:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56486 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728257AbgGBJYe (ORCPT ); Thu, 2 Jul 2020 05:24:34 -0400 Received: from mail-ed1-x542.google.com (mail-ed1-x542.google.com [IPv6:2a00:1450:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E01BC08C5DC for ; Thu, 2 Jul 2020 02:24:34 -0700 (PDT) Received: by mail-ed1-x542.google.com with SMTP id e22so22860060edq.8 for ; Thu, 02 Jul 2020 02:24:33 -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=DGjtMtRZoUSNqJptItw87hhXT8ibCTYEznJMwbsQq/g=; b=xAxCWfILjqrpUN7ZckPc11Mx/2WMpaf6Y2dNk7Lt/EKIGtsX0I2oZnPB8hQk6UxcpK 9Fy0tbEAdp459p1n8d7jF3OfW7En70lCyXFlVBUXDLQq/+2HrKayfbWMlheR1WzrJx0V +ruxkYusCQTRT3zyPlccPZdVgAWM0MxFinmHM= 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=DGjtMtRZoUSNqJptItw87hhXT8ibCTYEznJMwbsQq/g=; b=VotitTGpfgIHDMgFNwqMgys4RVLfd7Fe5XdgtZdgMrRGZeXhCPHsYGo9a5DcVzbyaw BOz+hcofGWOIvJrOd1iD9oXnAeRUTPDKW17KrO0BtKaKFZY9QdyKtygOhsWnjRqxV7sH +hfk7NuN6SNjpP518aeN5zinAghOYsGbXUWa3+gr3cJdPxvcjPeIypnsZiiwCYzRkp7S SbkFQgG3zbtlmtVK2Papi2mDv/WfxzJ+rzLqf81JE0AMP/BITIqVSSCUx+edwalOA2Em 92lpWk1MixDSW5td4e5XUmyu57Bb4GIEsliW/zNBTw8oI+4MuxfPDoh7080no3yw1woN 7sbA== X-Gm-Message-State: AOAM531gi14++8qCr2bxmm6MKoU0Kr0ku6cDPN+YkSwrsP1Em7dleeIg H22En0mjJ2efYD+kQFf0XYzw5GpdmmUC6A== X-Google-Smtp-Source: ABdhPJx1j8fq0x65QnrOyr+sY3IUavODoQxLhqIJQL0Ne6AVZd6lK9PtSBjhyUoDEjYriAkErY0tGQ== X-Received: by 2002:a05:6402:3113:: with SMTP id dc19mr32548877edb.20.1593681872550; Thu, 02 Jul 2020 02:24:32 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id v11sm6306081eja.113.2020.07.02.02.24.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 02:24:32 -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 v3 08/16] udp: Run SK_LOOKUP BPF program on socket lookup Date: Thu, 2 Jul 2020 11:24:08 +0200 Message-Id: <20200702092416.11961-9-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200702092416.11961-1-jakub@cloudflare.com> References: <20200702092416.11961-1-jakub@cloudflare.com> MIME-Version: 1.0 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 Signed-off-by: Jakub Sitnicki --- Notes: 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..c8f88b113f82 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 do_reuseport; + + if (udptable != &udp_table) + return NULL; /* only UDP is supported */ + + do_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_UDP, + saddr, sport, daddr, hnum, &sk); + if (do_reuseport) { + 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;