From patchwork Fri Nov 1 00:44:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francesco Ruggeri X-Patchwork-Id: 1187719 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=arista.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=arista.com header.i=@arista.com header.b="nCwvt4Ob"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4743PT2dH1z9sP4 for ; Fri, 1 Nov 2019 11:45:01 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727828AbfKAAoP (ORCPT ); Thu, 31 Oct 2019 20:44:15 -0400 Received: from mx.aristanetworks.com ([162.210.129.12]:46739 "EHLO smtp.aristanetworks.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727516AbfKAAoP (ORCPT ); Thu, 31 Oct 2019 20:44:15 -0400 Received: from us180.sjc.aristanetworks.com (us180.sjc.aristanetworks.com [172.25.230.4]) by smtp.aristanetworks.com (Postfix) with ESMTP id 45FE51E742; Thu, 31 Oct 2019 17:44:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=Arista-A; t=1572569054; bh=xqPgJttHCD12XhRX3JpEzUxG5V0ouLsJ2hx86TeINbU=; h=Date:To:Subject:Cc:From:From; b=nCwvt4Obh6jywht2gdRVmnOBeJCVghpi8rQZLv/cG853C3RskTHaSJrAN/5nBslaS o6iDW27vvTKtGjn2wz0lu9SMa9MtmZ8fH4lJLALZLwQscHwPkOQwXAJhBGxFRCyA5J RCcsciH6relxsnA83jd1KqU6cdLj0pUcHoVtR9vNSwnLBF/cqMGnZE6wV+EJiJxJu1 Zu1fA725/WjwQqG7SOemSaFu6ZHsFtKz1PAiG8/ORd3+KeHM0b1YCzUk9hwLw7daSC iuLSodLMlgLAz61al3slSSqqGbQBHKohKeAbv7ulaKOLvDvQkD+LAWwKZTwGgC3/mn Vy9ZBbSN50jDg== Received: by us180.sjc.aristanetworks.com (Postfix, from userid 10189) id 2B2F995C102D; Thu, 31 Oct 2019 17:44:14 -0700 (PDT) Date: Thu, 31 Oct 2019 17:44:13 -0700 To: kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, davem@davemloft.net, netdev@vger.kernel.org Subject: [PATCH net-next] net: icmp: use input address in traceroute Cc: fruggeri@arista.com User-Agent: Heirloom mailx 12.5 7/5/10 Message-Id: <20191101004414.2B2F995C102D@us180.sjc.aristanetworks.com> From: fruggeri@arista.com (Francesco Ruggeri) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Even with icmp_errors_use_inbound_ifaddr set, traceroute returns the primary address of the interface the packet was received on, even if the path goes through a secondary address. In the example: 1.0.3.1/24 ---- 1.0.1.3/24 1.0.1.1/24 ---- 1.0.2.1/24 1.0.2.4/24 ---- |H1|--------------------------|R1|--------------------------|H2| ---- N1 ---- N2 ---- where 1.0.3.1/24 is R1's primary address on N1, traceroute from H1 to H2 returns: traceroute to 1.0.2.4 (1.0.2.4), 30 hops max, 60 byte packets 1 1.0.3.1 (1.0.3.1) 0.018 ms 0.006 ms 0.006 ms 2 1.0.2.4 (1.0.2.4) 0.021 ms 0.007 ms 0.007 ms After applying this patch, it returns: traceroute to 1.0.2.4 (1.0.2.4), 30 hops max, 60 byte packets 1 1.0.1.1 (1.0.1.1) 0.033 ms 0.007 ms 0.006 ms 2 1.0.2.4 (1.0.2.4) 0.011 ms 0.007 ms 0.007 ms Original-patch-by: Bill Fenner Signed-off-by: Francesco Ruggeri Reviewed-by: David Ahern --- net/ipv4/icmp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 4298aae74e0e..a72fbdf1fb85 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -682,7 +682,8 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, dev = dev_get_by_index_rcu(net, inet_iif(skb_in)); if (dev) - saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK); + saddr = inet_select_addr(dev, iph->saddr, + RT_SCOPE_LINK); else saddr = 0; rcu_read_unlock();