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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id B5EE8C6FD1D for ; Mon, 20 Mar 2023 12:10:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1peELD-0004KG-2d; Mon, 20 Mar 2023 08:10:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1peELA-0004Js-Pb for qemu-devel@nongnu.org; Mon, 20 Mar 2023 08:10:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1peEL8-0004rZ-FU for qemu-devel@nongnu.org; Mon, 20 Mar 2023 08:10:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679314212; h=from:from:reply-to: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=kNzLS6JcwDNUk5uzD9Btx7Xd7xeoYUStGmsCKwIgd0c=; b=KugM3lYZVQNKPekaaYvECyn26BZBTrGuON1Ek15EL53WIs71sfDMgus+wM/1/pMkQgi4MQ JfpqV8ZsY6PPzbG1qjXQxUzrjWUbNotiwZBI7O52nbjzrEGSqdm4eIbQOQ/8j1hvLGaL2F gRZU669TXAIb1mtcunI7z1GDuYmG4us= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-453-zrnVo_hcNaiqTnQk7ILuyw-1; Mon, 20 Mar 2023 08:10:11 -0400 X-MC-Unique: zrnVo_hcNaiqTnQk7ILuyw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 491B1185A791; Mon, 20 Mar 2023 12:10:11 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.143]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6E8C3140EBF4; Mon, 20 Mar 2023 12:10:10 +0000 (UTC) Date: Mon, 20 Mar 2023 12:10:07 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: marcandre.lureau@redhat.com Cc: qemu-devel@nongnu.org, Stefan Weil , Gerd Hoffmann Subject: Re: [PATCH 1/3] win32: add qemu_close_to_socket() Message-ID: References: <20230320111412.1516419-1-marcandre.lureau@redhat.com> <20230320111412.1516419-2-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230320111412.1516419-2-marcandre.lureau@redhat.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Mar 20, 2023 at 03:14:10PM +0400, marcandre.lureau@redhat.com wrote: > From: Marc-André Lureau > > Close the given file descriptor, but returns the underlying SOCKET. > > Signed-off-by: Marc-André Lureau > --- > include/sysemu/os-win32.h | 1 + > util/oslib-win32.c | 68 +++++++++++++++++++++------------------ > 2 files changed, 38 insertions(+), 31 deletions(-) > > diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h > index e2849f88ab..95cba6b284 100644 > --- a/include/sysemu/os-win32.h > +++ b/include/sysemu/os-win32.h > @@ -174,6 +174,7 @@ bool qemu_socket_unselect(int sockfd, Error **errp); > /* We wrap all the sockets functions so that we can > * set errno based on WSAGetLastError() > */ > +SOCKET qemu_close_to_socket(int fd); Took me a while to understand what this function is actually doing. IIUC, it assumes 'fd' was previously created by _open_osfhandle, and close this OSF handle, leaving the SOCKET still open. Could we call this one 'qemu_close_socket_osfhandle' and also add a comment describing what this does. > > #undef close > #define close qemu_close_wrap > diff --git a/util/oslib-win32.c b/util/oslib-win32.c > index 16f8a67f7e..e37276b414 100644 > --- a/util/oslib-win32.c > +++ b/util/oslib-win32.c > @@ -479,52 +479,58 @@ int qemu_bind_wrap(int sockfd, const struct sockaddr *addr, > return ret; > } > > - > #undef close > -int qemu_close_wrap(int fd) > +SOCKET qemu_close_to_socket(int fd) > { > - int ret; > + SOCKET s = _get_osfhandle(fd); > DWORD flags = 0; > - SOCKET s = INVALID_SOCKET; > - > - if (fd_is_socket(fd)) { > - s = _get_osfhandle(fd); > > - /* > - * If we were to just call _close on the descriptor, it would close the > - * HANDLE, but it wouldn't free any of the resources associated to the > - * SOCKET, and we can't call _close after calling closesocket, because > - * closesocket has already closed the HANDLE, and _close would attempt to > - * close the HANDLE again, resulting in a double free. We can however > - * protect the HANDLE from actually being closed long enough to close the > - * file descriptor, then close the socket itself. > - */ > - if (!GetHandleInformation((HANDLE)s, &flags)) { > - errno = EACCES; > - return -1; > - } > - > - if (!SetHandleInformation((HANDLE)s, HANDLE_FLAG_PROTECT_FROM_CLOSE, HANDLE_FLAG_PROTECT_FROM_CLOSE)) { > - errno = EACCES; > - return -1; > - } > + /* > + * If we were to just call _close on the descriptor, it would close the > + * HANDLE, but it wouldn't free any of the resources associated to the > + * SOCKET, and we can't call _close after calling closesocket, because > + * closesocket has already closed the HANDLE, and _close would attempt to > + * close the HANDLE again, resulting in a double free. We can however > + * protect the HANDLE from actually being closed long enough to close the > + * file descriptor, then close the socket itself. > + */ > + if (!GetHandleInformation((HANDLE)s, &flags)) { > + errno = EACCES; > + return INVALID_SOCKET; > } > > - ret = close(fd); > - > - if (s != INVALID_SOCKET && !SetHandleInformation((HANDLE)s, flags, flags)) { > + if (!SetHandleInformation((HANDLE)s, HANDLE_FLAG_PROTECT_FROM_CLOSE, HANDLE_FLAG_PROTECT_FROM_CLOSE)) { > errno = EACCES; > - return -1; > + return INVALID_SOCKET; > } > > /* > * close() returns EBADF since we PROTECT_FROM_CLOSE the underlying handle, > * but the FD is actually freed > */ > - if (ret < 0 && (s == INVALID_SOCKET || errno != EBADF)) { > - return ret; > + if (close(fd) < 0 && errno != EBADF) { > + return INVALID_SOCKET; > + } > + > + if (!SetHandleInformation((HANDLE)s, flags, flags)) { > + errno = EACCES; > + return INVALID_SOCKET; > + } > + > + return s; > +} > + > +int qemu_close_wrap(int fd) > +{ > + SOCKET s = INVALID_SOCKET; > + int ret = -1; > + > + if (!fd_is_socket(fd)) { > + return close(fd); > } > > + s = qemu_close_to_socket(fd); > + > if (s != INVALID_SOCKET) { > ret = closesocket(s); > if (ret < 0) { > -- > 2.39.2 > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|