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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 32034C3A5A6 for ; Thu, 19 Sep 2019 22:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04BA921920 for ; Thu, 19 Sep 2019 22:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568930804; bh=ZfHd1jtfZQk+oHwecwNGPskZirVCtdQFTXO5g3EUvdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NtMWl+duK7G8hKsnXVI4hC0lR1axa1c+tHwksuiTfk0l3CCpPHR3bo1AWdsjsFiwa rtDCSmrCTTi20TbG1vroD9AIqqp2QgQeIemGutD8vd6swvag+TZ4/hg0/dHgyJxg8t LvbbA/n87tzIcfestcEaa/nMArnj+2pHc2SJHtdA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405262AbfISWGm (ORCPT ); Thu, 19 Sep 2019 18:06:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:44126 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405243AbfISWGj (ORCPT ); Thu, 19 Sep 2019 18:06:39 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 753EA218AF; Thu, 19 Sep 2019 22:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568930798; bh=ZfHd1jtfZQk+oHwecwNGPskZirVCtdQFTXO5g3EUvdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2lDol9xz4CsSbxIojOrZn9CHHpMOwbxb8qYtHWr4rscBIJ7hQgLFijCWeFxpFvuOl UQUBrNVmcqBPBGzNSz7Fkb3YpzIApIBpOeoAf3X+AGDKjpyi9JvdHot3rZEfSCvUpD 9GRAa/oR3EoI+6ZoOB3PbtkT2u3Dc/hEWxeFmms8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Willem de Bruijn , Paolo Abeni , Craig Gallek , "David S. Miller" Subject: [PATCH 5.2 018/124] udp: correct reuseport selection with connected sockets Date: Fri, 20 Sep 2019 00:01:46 +0200 Message-Id: <20190919214819.769727806@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214819.198419517@linuxfoundation.org> References: <20190919214819.198419517@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Willem de Bruijn [ Upstream commit acdcecc61285faed359f1a3568c32089cc3a8329 ] UDP reuseport groups can hold a mix unconnected and connected sockets. Ensure that connections only receive all traffic to their 4-tuple. Fast reuseport returns on the first reuseport match on the assumption that all matches are equal. Only if connections are present, return to the previous behavior of scoring all sockets. Record if connections are present and if so (1) treat such connected sockets as an independent match from the group, (2) only return 2-tuple matches from reuseport and (3) do not return on the first 2-tuple reuseport match to allow for a higher scoring match later. New field has_conns is set without locks. No other fields in the bitmap are modified at runtime and the field is only ever set unconditionally, so an RMW cannot miss a change. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Link: http://lkml.kernel.org/r/CA+FuTSfRP09aJNYRt04SS6qj22ViiOEWaWmLAwX0psk8-PGNxw@mail.gmail.com Signed-off-by: Willem de Bruijn Acked-by: Paolo Abeni Acked-by: Craig Gallek Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/sock_reuseport.h | 21 ++++++++++++++++++++- net/core/sock_reuseport.c | 15 +++++++++++++-- net/ipv4/datagram.c | 2 ++ net/ipv4/udp.c | 5 +++-- net/ipv6/datagram.c | 2 ++ net/ipv6/udp.c | 5 +++-- 6 files changed, 43 insertions(+), 7 deletions(-) --- a/include/net/sock_reuseport.h +++ b/include/net/sock_reuseport.h @@ -21,7 +21,8 @@ struct sock_reuseport { unsigned int synq_overflow_ts; /* ID stays the same even after the size of socks[] grows. */ unsigned int reuseport_id; - bool bind_inany; + unsigned int bind_inany:1; + unsigned int has_conns:1; struct bpf_prog __rcu *prog; /* optional BPF sock selector */ struct sock *socks[0]; /* array of sock pointers */ }; @@ -35,6 +36,24 @@ extern struct sock *reuseport_select_soc struct sk_buff *skb, int hdr_len); extern int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog); + +static inline bool reuseport_has_conns(struct sock *sk, bool set) +{ + struct sock_reuseport *reuse; + bool ret = false; + + rcu_read_lock(); + reuse = rcu_dereference(sk->sk_reuseport_cb); + if (reuse) { + if (set) + reuse->has_conns = 1; + ret = reuse->has_conns; + } + rcu_read_unlock(); + + return ret; +} + int reuseport_get_id(struct sock_reuseport *reuse); #endif /* _SOCK_REUSEPORT_H */ --- a/net/core/sock_reuseport.c +++ b/net/core/sock_reuseport.c @@ -295,8 +295,19 @@ struct sock *reuseport_select_sock(struc select_by_hash: /* no bpf or invalid bpf result: fall back to hash usage */ - if (!sk2) - sk2 = reuse->socks[reciprocal_scale(hash, socks)]; + if (!sk2) { + int i, j; + + i = j = reciprocal_scale(hash, socks); + while (reuse->socks[i]->sk_state == TCP_ESTABLISHED) { + i++; + if (i >= reuse->num_socks) + i = 0; + if (i == j) + goto out; + } + sk2 = reuse->socks[i]; + } } out: --- a/net/ipv4/datagram.c +++ b/net/ipv4/datagram.c @@ -15,6 +15,7 @@ #include #include #include +#include int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { @@ -69,6 +70,7 @@ int __ip4_datagram_connect(struct sock * } inet->inet_daddr = fl4->daddr; inet->inet_dport = usin->sin_port; + reuseport_has_conns(sk, true); sk->sk_state = TCP_ESTABLISHED; sk_set_txhash(sk); inet->inet_id = jiffies; --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -434,12 +434,13 @@ static struct sock *udp4_lib_lookup2(str score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif, exact_dif); if (score > badness) { - if (sk->sk_reuseport) { + if (sk->sk_reuseport && + sk->sk_state != TCP_ESTABLISHED) { hash = udp_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (result) + if (result && !reuseport_has_conns(sk, false)) return result; } badness = score; --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -254,6 +255,7 @@ ipv4_connected: goto out; } + reuseport_has_conns(sk, true); sk->sk_state = TCP_ESTABLISHED; sk_set_txhash(sk); out: --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -168,13 +168,14 @@ static struct sock *udp6_lib_lookup2(str score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif, exact_dif); if (score > badness) { - if (sk->sk_reuseport) { + if (sk->sk_reuseport && + sk->sk_state != TCP_ESTABLISHED) { hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); result = reuseport_select_sock(sk, hash, skb, sizeof(struct udphdr)); - if (result) + if (result && !reuseport_has_conns(sk, false)) return result; } result = sk;