From nobody Fri Apr 26 10:40:15 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1493381816290829.4655570459752; Fri, 28 Apr 2017 05:16:56 -0700 (PDT) Received: from localhost ([::1]:36817 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d44pS-0001LX-7G for importer@patchew.org; Fri, 28 Apr 2017 08:16:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38762) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d44oj-00014e-4C for qemu-devel@nongnu.org; Fri, 28 Apr 2017 08:16:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d44oe-0001Cq-5C for qemu-devel@nongnu.org; Fri, 28 Apr 2017 08:16:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58566) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d44od-0001Bk-TC for qemu-devel@nongnu.org; Fri, 28 Apr 2017 08:16:04 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9A448A08F6 for ; Fri, 28 Apr 2017 12:16:02 +0000 (UTC) Received: from t460.redhat.com (ovpn-117-183.ams2.redhat.com [10.36.117.183]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9DB658821A; Fri, 28 Apr 2017 12:15:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9A448A08F6 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=berrange@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 9A448A08F6 From: "Daniel P. Berrange" To: qemu-devel@nongnu.org Date: Fri, 28 Apr 2017 13:15:53 +0100 Message-Id: <20170428121553.22408-1-berrange@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 28 Apr 2017 12:16:02 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] sockets: ensure we can bind to both ipv4 & ipv6 separately X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Gerd Hoffmann Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" When binding to an IPv6 socket we currently force the IPV6_V6ONLY flag to off. This means that the IPv6 socket will accept both IPv4 & IPv6 sockets when QEMU is launched with something like -vnc :::1 While this is good for that case, it is bad for other cases. For example if an empty hostname is given, getaddrinfo resolves it to 2 addresses 0.0.0.0 and ::, in that order. We will thus bind to 0.0.0.0 first, and then fail to bind to :: on the same port. The same problem can happen if any other hostname lookup causes the IPv4 address to be reported before the IPv6 address. When we get an IPv6 bind failure, we should re-try the same port, but with IPV6_V6ONLY turned on again, to avoid clash with any IPv4 listener. This ensures that -vnc :1 will bind successfully to both 0.0.0.0 and ::, and also avoid -vnc :1,to=3D2 from mistakenly using a 2nd port for the :: listener. Signed-off-by: Daniel P. Berrange Reviewed-by: Eric Blake --- util/qemu-sockets.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index 8188d9a..75d1e0f 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -207,22 +207,36 @@ static int inet_listen_saddr(InetSocketAddress *saddr, } =20 socket_set_fast_reuse(slisten); -#ifdef IPV6_V6ONLY - if (e->ai_family =3D=3D PF_INET6) { - /* listen on both ipv4 and ipv6 */ - const int off =3D 0; - qemu_setsockopt(slisten, IPPROTO_IPV6, IPV6_V6ONLY, &off, - sizeof(off)); - } -#endif =20 port_min =3D inet_getport(e); port_max =3D saddr->has_to ? saddr->to + port_offset : port_min; for (p =3D port_min; p <=3D port_max; p++) { inet_setport(e, p); +#ifdef IPV6_V6ONLY + if (e->ai_family =3D=3D PF_INET6) { + /* listen on both ipv4 and ipv6 */ + const int off =3D 0; + qemu_setsockopt(slisten, IPPROTO_IPV6, IPV6_V6ONLY, &off, + sizeof(off)); + } +#endif if (bind(slisten, e->ai_addr, e->ai_addrlen) =3D=3D 0) { goto listen; } + +#ifdef IPV6_V6ONLY + if (e->ai_family =3D=3D PF_INET6 && errno =3D=3D EADDRINUSE) { + /* listen on only ipv6 */ + const int on =3D 1; + qemu_setsockopt(slisten, IPPROTO_IPV6, IPV6_V6ONLY, &on, + sizeof(on)); + + if (bind(slisten, e->ai_addr, e->ai_addrlen) =3D=3D 0) { + goto listen; + } + } +#endif + if (p =3D=3D port_max) { if (!e->ai_next) { error_setg_errno(errp, errno, "Failed to bind socket"); --=20 2.9.3