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=-7.0 required=3.0 tests=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 5573DC04AB4 for ; Thu, 16 May 2019 08:47:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C7E620881 for ; Thu, 16 May 2019 08:47:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C7E620881 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:50752 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRC38-0007S3-8K for qemu-devel@archiver.kernel.org; Thu, 16 May 2019 04:47:38 -0400 Received: from eggs.gnu.org ([209.51.188.92]:34759) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hRC1e-0006Xu-MW for qemu-devel@nongnu.org; Thu, 16 May 2019 04:46:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hRC01-0002W2-Lw for qemu-devel@nongnu.org; Thu, 16 May 2019 04:44:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32946) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hRC01-0002U3-Dc for qemu-devel@nongnu.org; Thu, 16 May 2019 04:44:25 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 78EAD307D9D0 for ; Thu, 16 May 2019 08:44:23 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-28.ams2.redhat.com [10.36.116.28]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BEB771001DC5; Thu, 16 May 2019 08:44:21 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1D79B11385E4; Thu, 16 May 2019 10:44:20 +0200 (CEST) From: Markus Armbruster To: Stefano Garzarella References: <20190509130345.227526-1-sgarzare@redhat.com> <20190509130345.227526-3-sgarzare@redhat.com> Date: Thu, 16 May 2019 10:44:20 +0200 In-Reply-To: <20190509130345.227526-3-sgarzare@redhat.com> (Stefano Garzarella's message of "Thu, 9 May 2019 15:03:43 +0200") Message-ID: <877eaqvlej.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 16 May 2019 08:44:23 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v2 2/4] net: avoid using variable length array in net_client_init() 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: Jason Wang , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Stefano Garzarella writes: > net_client_init() uses a variable length array to store the prefix > of 'ipv6-net' parameter (e.g. if ipv6-net=fec0::0/64, the prefix > is 'fec0::0'). > This patch introduces g_strsplit() to split the 'ipv6-net' parameter, > so we can remove the variable length array. > > Suggested-by: Markus Armbruster > Signed-off-by: Stefano Garzarella > --- > net/net.c | 33 +++++++++++++++++++++------------ > 1 file changed, 21 insertions(+), 12 deletions(-) > > diff --git a/net/net.c b/net/net.c > index d5071e49e2..932fa5abb5 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -1118,29 +1118,38 @@ static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp) > const char *ip6_net = qemu_opt_get(opts, "ipv6-net"); > > if (ip6_net) { > - char buf[strlen(ip6_net) + 1]; > + gchar **substrings; > + char *prefix_addr; > + unsigned long prefix_len = 64; /* Default 64bit prefix length. */ > > - if (get_str_sep(buf, sizeof(buf), &ip6_net, '/') < 0) { > - /* Default 64bit prefix length. */ > - qemu_opt_set(opts, "ipv6-prefix", ip6_net, &error_abort); > - qemu_opt_set_number(opts, "ipv6-prefixlen", 64, &error_abort); > - } else { > + substrings = g_strsplit(ip6_net, "/", 2); > + if (!substrings || !substrings[0]) { > + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, > + "ipv6-net", "a valid IPv6 prefix"); > + g_strfreev(substrings); > + goto out; Indentation's off. > + } > + > + *prefix_addr = substrings[0]; > + > + if (substrings[1]) { > /* User-specified prefix length. */ > - unsigned long len; > int err; > > - qemu_opt_set(opts, "ipv6-prefix", buf, &error_abort); > - err = qemu_strtoul(ip6_net, NULL, 10, &len); > - > + err = qemu_strtoul(substrings[1], NULL, 10, &prefix_len); > if (err) { > error_setg(errp, QERR_INVALID_PARAMETER_VALUE, > "ipv6-prefixlen", "a number"); > + g_strfreev(substrings); > goto out; Two g_strfreev() before goto out. Avoidable: declare substrings at the function level, initialize to NULL, then call g_strfreev(substrings) ... > } > - > - qemu_opt_set_number(opts, "ipv6-prefixlen", len, &error_abort); > } > + > + qemu_opt_set(opts, "ipv6-prefix", prefix_addr, &error_abort); > + qemu_opt_set_number(opts, "ipv6-prefixlen", prefix_len, > + &error_abort); > qemu_opt_unset(opts, "ipv6-net"); > + g_strfreev(substrings); > } > } if (is_netdev) { visit_type_Netdev(v, NULL, (Netdev **)&object, &err); } else { visit_type_NetLegacy(v, NULL, (NetLegacy **)&object, &err); } if (!err) { ret = net_client_init1(object, is_netdev, &err); } if (is_netdev) { qapi_free_Netdev(object); } else { qapi_free_NetLegacy(object); } out: error_propagate(errp, err); ... here. Your choice. visit_free(v); return ret; } With at least the indentation fixed: Reviewed-by: Markus Armbruster Not this patch's problem: when visit_type_FOO() fails with an input visitor such as @v, you should not call qapi_free_FOO(). Nothing bad happens when you do, it's just sloppy. See visitor.h's big comment for details. Cleaner: if (is_netdev) { visit_type_Netdev(v, NULL, (Netdev **)&object, &err); } else { visit_type_NetLegacy(v, NULL, (NetLegacy **)&object, &err); } if (err) { goto out; } ret = net_client_init1(object, is_netdev, &err); if (is_netdev) { qapi_free_Netdev(object); } else { qapi_free_NetLegacy(object); } out: Or maybe: if (is_netdev) { visit_type_Netdev(v, NULL, &netdev, &err); if (err) { goto out; } ret = net_client_init1(netdev, is_netdev, &err); qapi_free_Netdev(netdev); } else { visit_type_NetLegacy(v, NULL, &netlegacy, &err); if (err) { goto out; } ret = net_client_init1(netlegacy, is_netdev, &err); qapi_free_NetLegacy(netlegacy); } out: with Netdev *netdev; NetLegacy *netlegacy; replacing @object. Or one step further: observe net_client_init() is always called with a compile-time constant second argument. Split it into two functions, factor the common part into a helper.