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 61F3CC6FD1D for ; Mon, 20 Mar 2023 13:53:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1peFwn-0001pF-Mi; Mon, 20 Mar 2023 09:53:14 -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 1peFwf-0001on-PF for qemu-devel@nongnu.org; Mon, 20 Mar 2023 09:53:05 -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 1peFwd-0007Di-Ti for qemu-devel@nongnu.org; Mon, 20 Mar 2023 09:53:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679320383; 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=Uf0OusqLnHXmqntlsAY91aZ4ZVjcm5CqnFrcQOaPOc0=; b=Ij16Z+C+5U7ktr9BnAgc42UJeP3PNaRCE5nBvctvWc/6O/Z3wu4pxkTGC8HTpJvmiRpMdG x4T/OqMZYN62ePiPc9xruvEJ9XCYFESUcrHpoAWzqZrKRy0CfnYSdEWYB06APz0y7VqN2E 0x2BhMDQOb5xc3Duui27XH8U2BlrC8w= 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-417-HaVjJmOoP12YHCaKT68LCA-1; Mon, 20 Mar 2023 09:53:00 -0400 X-MC-Unique: HaVjJmOoP12YHCaKT68LCA-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 9AF15885626; Mon, 20 Mar 2023 13:52:59 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.143]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D91CE140EBF4; Mon, 20 Mar 2023 13:52:57 +0000 (UTC) Date: Mon, 20 Mar 2023 13:52:55 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, Stefan Weil , Gerd Hoffmann Subject: Re: [PATCH v2 1/3] win32: add qemu_close_socket_osfhandle() Message-ID: References: <20230320133643.1618437-1-marcandre.lureau@redhat.com> <20230320133643.1618437-2-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: 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 05:46:01PM +0400, Marc-André Lureau wrote: > Hi > > On Mon, Mar 20, 2023 at 5:42 PM Daniel P. Berrangé > wrote: > > > On Mon, Mar 20, 2023 at 05:36:41PM +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 | 15 ++++++-- > > > util/oslib-win32.c | 75 +++++++++++++++++++++------------------ > > > 2 files changed, 53 insertions(+), 37 deletions(-) > > > > > > diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h > > > index e2849f88ab..15c296e0eb 100644 > > > --- a/include/sysemu/os-win32.h > > > +++ b/include/sysemu/os-win32.h > > > @@ -171,10 +171,21 @@ bool qemu_socket_select(int sockfd, WSAEVENT > > hEventObject, > > > > > > bool qemu_socket_unselect(int sockfd, Error **errp); > > > > > > -/* We wrap all the sockets functions so that we can > > > - * set errno based on WSAGetLastError() > > > +/* We wrap all the sockets functions so that we can set errno based on > > > + * WSAGetLastError(), and use file-descriptors instead of SOCKET. > > > */ > > > > > > +/* > > > + * qemu_close_socket_osfhandle: > > > + * @fd: a file descriptor associated with a SOCKET > > > + * > > > + * Close only the C run-time file descriptor, leave the SOCKET opened. > > > + * > > > + * Returns zero on success. On error, -1 is returned, and errno is set > > to > > > + * indicate the error. > > > + */ > > > +int qemu_close_socket_osfhandle(int fd); > > > + > > > #undef close > > > #define close qemu_close_wrap > > > int qemu_close_wrap(int fd); > > > diff --git a/util/oslib-win32.c b/util/oslib-win32.c > > > index 16f8a67f7e..a98638729a 100644 > > > --- a/util/oslib-win32.c > > > +++ b/util/oslib-win32.c > > > @@ -479,40 +479,27 @@ int qemu_bind_wrap(int sockfd, const struct > > sockaddr *addr, > > > return ret; > > > } > > > > > > - > > > #undef close > > > -int qemu_close_wrap(int fd) > > > +int qemu_close_socket_osfhandle(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 -1; > > > } > > > > > > - 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; > > > } > > > @@ -521,15 +508,33 @@ int qemu_close_wrap(int fd) > > > * 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 -1; > > > } > > > > > > - if (s != INVALID_SOCKET) { > > > - ret = closesocket(s); > > > - if (ret < 0) { > > > - errno = socket_error(); > > > - } > > > + if (!SetHandleInformation((HANDLE)s, flags, flags)) { > > > + errno = EACCES; > > > + return -1; > > > + } > > > + > > > + return 0; > > > +} > > > + > > > +int qemu_close_wrap(int fd) > > > +{ > > > + SOCKET s = INVALID_SOCKET; > > > + int ret = -1; > > > + > > > + if (!fd_is_socket(fd)) { > > > + return close(fd); > > > + } > > > + > > > + s = _get_osfhandle(fd); > > > + qemu_close_socket_osfhandle(fd); > > > + > > > + ret = closesocket(s); > > > + if (ret < 0) { > > > + errno = socket_error(); > > > } > > > > Shouldn't the closesocket() and return check be wrapped in > > > > if (s != INVALID_SOCKET) { .... } > > > > > We shouldn't get there since fd_is_socket(). Oh right, yes, fd_is_socket() will evaluate false if the 'fd' is invalid. eg qemu_clsoe_wrap(-1) > > as the old code had that conditional invokation of closesocket() ? > > > > The v1 code could actually leak a SOCKET. This version should be a bit > better, if the FD is already closed for example, we still close the SOCKET. > > Open to ideas to improve it. Reviewed-by: Daniel P. Berrangé 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 :|