From patchwork Tue Apr 2 15:49:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Capitulino X-Patchwork-Id: 233071 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 1D4452C015F for ; Wed, 3 Apr 2013 02:52:10 +1100 (EST) Received: from localhost ([::1]:59240 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UN3VI-0007dQ-BR for incoming@patchwork.ozlabs.org; Tue, 02 Apr 2013 11:52:08 -0400 Received: from eggs.gnu.org ([208.118.235.92]:50564) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UN3TA-0004Hc-Uj for qemu-devel@nongnu.org; Tue, 02 Apr 2013 11:49:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UN3T8-0004gI-Sa for qemu-devel@nongnu.org; Tue, 02 Apr 2013 11:49:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59459) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UN3T8-0004g6-KR for qemu-devel@nongnu.org; Tue, 02 Apr 2013 11:49:54 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r32FnrtL027316 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 2 Apr 2013 11:49:54 -0400 Received: from localhost (ovpn-113-147.phx2.redhat.com [10.3.113.147]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r32FnrEg009871; Tue, 2 Apr 2013 11:49:53 -0400 From: Luiz Capitulino To: qemu-devel@nongnu.org Date: Tue, 2 Apr 2013 11:49:47 -0400 Message-Id: <1364917787-17689-5-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1364917787-17689-1-git-send-email-lcapitulino@redhat.com> References: <1364917787-17689-1-git-send-email-lcapitulino@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: aliguori@us.ibm.com Subject: [Qemu-devel] [PULL 4/4] chardev: clear O_NONBLOCK on SCM_RIGHTS file descriptors X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Stefan Hajnoczi When we receive a file descriptor over a UNIX domain socket the O_NONBLOCK flag is preserved. Clear the O_NONBLOCK flag and rely on QEMU file descriptor users like migration, SPICE, VNC, block layer, and others to set non-blocking only when necessary. This change ensures we don't accidentally expose O_NONBLOCK in the QMP API. QMP clients should not need to get the non-blocking state "correct". A recent real-world example was when libvirt passed a non-blocking TCP socket for migration where we expected a blocking socket. The source QEMU produced a corrupted migration stream since its code did not cope with non-blocking sockets. Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Signed-off-by: Luiz Capitulino --- qemu-char.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/qemu-char.c b/qemu-char.c index 4d8c6ca..d825b60 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2440,6 +2440,9 @@ static void unix_process_msgfd(CharDriverState *chr, struct msghdr *msg) if (fd < 0) continue; + /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */ + qemu_set_block(fd); + #ifndef MSG_CMSG_CLOEXEC qemu_set_cloexec(fd); #endif