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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 84266C433DF for ; Sun, 24 May 2020 18:14:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 545282076C for ; Sun, 24 May 2020 18:14:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uROJY5aL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387939AbgEXSOz (ORCPT ); Sun, 24 May 2020 14:14:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387823AbgEXSOz (ORCPT ); Sun, 24 May 2020 14:14:55 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC5FEC061A0E for ; Sun, 24 May 2020 11:14:54 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id 4so15600181ilg.1 for ; Sun, 24 May 2020 11:14:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=knRoLeUIqLg/Si1yu8wBCgp2c3s+wekXpjchWvvQ90I=; b=uROJY5aL0zIE+TxnW4O6Nb2rAK3jh4VN6X81kgw2wVn+KA2Sk24KoDBf7MwgGay8mH GUYDfvwCfHORzb0y9cgu3zk1LXn/lOFh3r2aVG4jOE6mCg7yYd6iW8mkK4VxO2CWViXU XxJr56617V6BKJIkKny+F53SFzOSqOQ+nar08EL+Bk84heTL4m9IqeEsxgVEn5CL68DK EkUwMvmFxPcxemMm92KLKk8EK5LZ/Qv1lXAgHCVD/gT6STdW2tUvSIPnCo8BH9LaFYjG ipowmBD0i/sg553QysNSVjVQwKpe57HuMlgEujaSidWszEM2BNfd+6wGT2RsGObO0xwh Rwfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=knRoLeUIqLg/Si1yu8wBCgp2c3s+wekXpjchWvvQ90I=; b=rjWRATJx4fPWdsCCEREcih2xqMDq1AP4bwu6aCf7lWmO8NBhKjs7ycJSJpJcaO2xl4 n1YxYf7b0MolFrWEczY7Zbfn/qqGwJ5NDqHHVDz6Omip3WvHtyfubjp6Fpvujb5k96qa eAeYVoff7pP70uV79ms99KgC14MmShXn8VAUeEws+Jt4TUQFC2iFt0usiwu6cVQoTmnA K3QpU7ExwnaBBb0azanjAQYkSHtboD6HFrg0ko9khaRE6hLBTj/5XokMjh/0L+GHhk2r 0a21A4i73pZwfxT5+6MsdRI1qgttzDS2g7O5bIy4W2fy5IcsxD7QFsm6BBrHzIn2uab6 8VCA== X-Gm-Message-State: AOAM532AMcn//uarTkZtHu1KeNzrAQ0tDdVxXrdoSYMibkJY1w2NfZon YZBlkkDYZEXqj2eWD+aa85WEArL4kDIYeSqi6APi+w== X-Google-Smtp-Source: ABdhPJwovVLgjD20WubNIexJSVrLtg7yoXwTZNrSLoXjsWnSW3hgA6+/6E9xV3DPbRTC50FkAEpdoGzmfAm6EsDZTf8= X-Received: by 2002:a05:6e02:788:: with SMTP id q8mr21623937ils.56.1590344093966; Sun, 24 May 2020 11:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20200524180002.148619-1-edumazet@google.com> In-Reply-To: <20200524180002.148619-1-edumazet@google.com> From: =?UTF-8?Q?Maciej_=C5=BBenczykowski?= Date: Sun, 24 May 2020 11:14:41 -0700 Message-ID: Subject: Re: [PATCH net-next] tcp: allow traceroute -Mtcp for unpriv users To: Eric Dumazet Cc: "David S . Miller" , netdev , Eric Dumazet , Willem de Bruijn Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, May 24, 2020 at 11:00 AM Eric Dumazet wrote: > > Unpriv users can use traceroute over plain UDP sockets, but not TCP ones. > > $ traceroute -Mtcp 8.8.8.8 > You do not have enough privileges to use this traceroute method. > > $ traceroute -n -Mudp 8.8.8.8 > traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets > 1 192.168.86.1 3.631 ms 3.512 ms 3.405 ms > 2 10.1.10.1 4.183 ms 4.125 ms 4.072 ms > 3 96.120.88.125 20.621 ms 19.462 ms 20.553 ms > 4 96.110.177.65 24.271 ms 25.351 ms 25.250 ms > 5 69.139.199.197 44.492 ms 43.075 ms 44.346 ms > 6 68.86.143.93 27.969 ms 25.184 ms 25.092 ms > 7 96.112.146.18 25.323 ms 96.112.146.22 25.583 ms 96.112.146.26 24.5= 02 ms > 8 72.14.239.204 24.405 ms 74.125.37.224 16.326 ms 17.194 ms > 9 209.85.251.9 18.154 ms 209.85.247.55 14.449 ms 209.85.251.9 26.296= ms^C > > We can easily support traceroute over TCP, by queueing an error message > into socket error queue. > > Note that applications need to set IP_RECVERR/IPV6_RECVERR option to > enable this feature, and that the error message is only queued > while in SYN_SNT state. > > socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) =3D 3 > setsockopt(3, SOL_IPV6, IPV6_RECVERR, [1], 4) =3D 0 > setsockopt(3, SOL_SOCKET, SO_TIMESTAMP_OLD, [1], 4) =3D 0 > setsockopt(3, SOL_IPV6, IPV6_UNICAST_HOPS, [5], 4) =3D 0 > connect(3, {sa_family=3DAF_INET6, sin6_port=3Dhtons(8787), sin6_flowinfo= =3Dhtonl(0), > inet_pton(AF_INET6, "2002:a05:6608:297::", &sin6_addr), sin6_scop= e_id=3D0}, 28) =3D -1 EHOSTUNREACH (No route to host) > recvmsg(3, {msg_name=3D{sa_family=3DAF_INET6, sin6_port=3Dhtons(8787), si= n6_flowinfo=3Dhtonl(0), > inet_pton(AF_INET6, "2002:a05:6608:297::", &sin6_addr), sin6_scop= e_id=3D0}, > msg_namelen=3D1024->28, msg_iov=3D[{iov_base=3D"`\r\337\320\0004\= 6\1&\7\370\260\200\231\16\27\0\0\0\0\0\0\0\0 \2\n\5f\10\2\227"..., iov_len= =3D1024}], > msg_iovlen=3D1, msg_control=3D[{cmsg_len=3D32, cmsg_level=3DSOL_S= OCKET, cmsg_type=3DSO_TIMESTAMP_OLD, cmsg_data=3D{tv_sec=3D1590340680, tv_u= sec=3D272424}}, > {cmsg_len=3D60, cmsg_level=3DSOL_IPV6,= cmsg_type=3DIPV6_RECVERR}], > msg_controllen=3D96, msg_flags=3DMSG_ERRQUEUE}, MSG_ERRQUEUE) =3D= 144 > > Suggested-by: Maciej =C5=BBenczykowski Signed-off-by: Eric Dumazet > Cc: Willem de Bruijn > --- > net/ipv4/tcp_ipv4.c | 2 ++ > net/ipv6/tcp_ipv6.c | 2 ++ > 2 files changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 6c05f1ceb538cbb9981835440163485de2ccf716..900c6d154cbcf04fb09d71f14= 45d0723bcf3c409 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -573,6 +573,8 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info) > if (fastopen && !fastopen->sk) > break; > > + ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th); > + > if (!sock_owned_by_user(sk)) { > sk->sk_err =3D err; > > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > index 413b3425ac66bd758bb83562efa955f277da90a5..01a6f5111a77b4397038bf4d4= 0cc09a94e57408c 100644 > --- a/net/ipv6/tcp_ipv6.c > +++ b/net/ipv6/tcp_ipv6.c > @@ -463,6 +463,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct ine= t6_skb_parm *opt, > if (fastopen && !fastopen->sk) > break; > > + ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 = *)th); > + > if (!sock_owned_by_user(sk)) { > sk->sk_err =3D err; > sk->sk_error_report(sk); /* Wake p= eople up to see the error (see connect in sock.c) */ > -- > 2.27.0.rc0.183.gde8f92d652-goog Thanks! I was not expecting it to be this easy... Reviewed-by: Maciej =C5=BBenczykowski