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=-11.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 18B6CC55178 for ; Thu, 29 Oct 2020 19:55:43 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6776020825 for ; Thu, 29 Oct 2020 19:55:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AbeYoNiv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6776020825 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 ([::1]:34398 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kYE1M-0006HD-Md for qemu-devel@archiver.kernel.org; Thu, 29 Oct 2020 15:55:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45392) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYE0e-0005r8-8V for qemu-devel@nongnu.org; Thu, 29 Oct 2020 15:54:56 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30622) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kYE0b-0007cy-FW for qemu-devel@nongnu.org; Thu, 29 Oct 2020 15:54:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604001291; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+GZezBL9p9/kUmg1vUhDMUQyZljjZZkc9oKX7dqdzKw=; b=AbeYoNiv4aFG6xLoVWZJgJ2+LlLZ+uUIUU6MrHwWHNJ1Tk1ILHjNRs5RMVKww96RwB6MNw wnQcu2iDIgNRG5KmzJ7zKyFFQ5/zPQnoxPYx7MZtQX3gb8R87Gxp2JUWmZfT3ejJEOvvJE DP2TR30XrXYdupqBKki5+Si8H90XB0g= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-374-q_LVFiGIMy-f0ZoEpciocA-1; Thu, 29 Oct 2020 15:54:48 -0400 X-MC-Unique: q_LVFiGIMy-f0ZoEpciocA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 457F6802B63; Thu, 29 Oct 2020 19:54:46 +0000 (UTC) Received: from [10.3.112.145] (ovpn-112-145.phx2.redhat.com [10.3.112.145]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8833D60C17; Thu, 29 Oct 2020 19:54:39 +0000 (UTC) To: Markus Armbruster , qemu-devel@nongnu.org References: <20201029133833.3450220-1-armbru@redhat.com> <20201029133833.3450220-12-armbru@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Subject: Re: [PATCH 11/11] sockets: Make abstract UnixSocketAddress depend on CONFIG_LINUX Message-ID: <77c4d3b2-44f0-2bf8-feb6-bc760b2b8c46@redhat.com> Date: Thu, 29 Oct 2020 14:54:38 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 MIME-Version: 1.0 In-Reply-To: <20201029133833.3450220-12-armbru@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/29 01:47:28 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.261, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, berrange@redhat.com, zxq_yx_007@163.com, kraxel@redhat.com, pbonzini@redhat.com, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 10/29/20 8:38 AM, Markus Armbruster wrote: > The abstract socket namespace is a non-portable Linux extension. An > attempt to use it elsewhere should fail with ENOENT (the abstract > address looks like a "" pathname, which does not resolve). We report > this failure like > > Failed to connect socket abc: No such file or directory > > Tolerable, although ENOTSUP would be better. > > However, introspection lies: it has @abstract regardless of host > support. Easy enough to fix: since Linux provides them since 2.2, > 'if': 'defined(CONFIG_LINUX)' should do. > > The above failure becomes > > Parameter 'backend.data.addr.data.abstract' is unexpected > > I consider this an improvement. > > Signed-off-by: Markus Armbruster > --- > +++ b/qapi/sockets.json > @@ -74,18 +74,20 @@ > # Captures a socket address in the local ("Unix socket") namespace. > # > # @path: filesystem path to use > -# @tight: pass a socket address length confined to the minimum length of the > -# abstract string, rather than the full sockaddr_un record length > -# (only matters for abstract sockets, default true). (Since 5.1) > -# @abstract: whether this is an abstract address, default false. (Since 5.1) > +# @abstract: if true, this is a Linux abstract socket address. @path > +# will be prefixed by a null byte, and optionally padded > +# with null bytes. Defaults to false. (Since 5.1) > +# @tight: if false, pad an abstract socket address with enough null > +# bytes to make it fill struct sockaddr_un member sun_path. > +# Defaults to true. (Since 5.1) Do we need to mention that @tight is ignored (or even make it an error) if @abstract is false? > # > # Since: 1.3 > ## > { 'struct': 'UnixSocketAddress', > 'data': { > 'path': 'str', > - '*tight': 'bool', > - '*abstract': 'bool' } } > + '*tight': { 'type': 'bool', 'if': 'defined(CONFIG_LINUX)' }, > + '*abstract': { 'type': 'bool', 'if': 'defined(CONFIG_LINUX)' } } } So we document @abstract before @tight, but declare them in reverse order. I guess our doc generator doesn't care? > > ## > # @VsockSocketAddress: > diff --git a/chardev/char-socket.c b/chardev/char-socket.c > index dc1cf86ecf..1d2b2efb13 100644 > --- a/chardev/char-socket.c > +++ b/chardev/char-socket.c > @@ -444,14 +444,20 @@ static char *qemu_chr_socket_address(SocketChardev *s, const char *prefix) > break; > case SOCKET_ADDRESS_TYPE_UNIX: > { > +#ifdef CONFIG_LINUX > UnixSocketAddress *sa = &s->addr->u.q_unix; > +#endif > > return g_strdup_printf("%sunix:%s%s%s%s", prefix, > s->addr->u.q_unix.path, Why did we need the #ifdef above, which means we can't we use sa here? > +#ifdef CONFIG_LINUX > sa->has_abstract && sa->abstract I hate mid-()-expression #ifdefs. If g_strdup_printf() were itself a macro expansion, things break. Can you come up with a saner way of writing this? > ? ",abstract" : "", > sa->has_tight && sa->tight > ? ",tight" : "", > +#else > + "", "", > +#endif > s->is_listen ? ",server" : ""); I suggest: const char *tight = "", *abstract = ""; UnixSocketAddress *sa = &s->addr->u.q_unix; #ifdef CONFIG_LINUX if (sa->has_abstract && sa->abstract) { abstract = ",abstract"; if (sa->has_tight && sa->tight) { tight = ",tight"; } } #endif return g_strdup_printf("%sunix:%s%s%s%s", prefix, sa->path, abstract, tight, s->is_listen ? ", server" : ""); > +++ b/util/qemu-sockets.c > @@ -854,10 +854,29 @@ static int vsock_parse(VsockSocketAddress *addr, const char *str, > > #ifndef _WIN32 > > +static bool saddr_is_abstract(UnixSocketAddress *saddr) > +{ > +#ifdef CONFIG_LINUX > + return saddr->abstract; > +#else > + return false; > +#endif > +} > + > +static bool saddr_is_tight(UnixSocketAddress *saddr) > +{ > +#ifdef CONFIG_LINUX > + return !saddr->has_tight || saddr->tight; Should this also look at abstract? > +#else > + return false; > +#endif > +} > + Is it any easier to split the patch, first into the introduction of saddr_is_* and adjusting all clients, and second into adding the 'if' to the QAPI declaration? But the idea makes sense. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org