From patchwork Tue Oct 22 03:25:32 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lei Li X-Patchwork-Id: 285334 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 9501B2C016B for ; Tue, 22 Oct 2013 14:29:55 +1100 (EST) Received: from localhost ([::1]:42773 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VYSfJ-0002yI-F6 for incoming@patchwork.ozlabs.org; Mon, 21 Oct 2013 23:29:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47257) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VYSbs-0005No-M8 for qemu-devel@nongnu.org; Mon, 21 Oct 2013 23:26:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VYSbj-0004Xg-OF for qemu-devel@nongnu.org; Mon, 21 Oct 2013 23:26:20 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:48067) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VYSbj-0004XV-6q for qemu-devel@nongnu.org; Mon, 21 Oct 2013 23:26:11 -0400 Received: from /spool/local by e28smtp08.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 22 Oct 2013 08:56:08 +0530 Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 278A2E004A for ; Tue, 22 Oct 2013 08:57:38 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r9M3Q3Qc42533082 for ; Tue, 22 Oct 2013 08:56:04 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r9M3Q6E3023263 for ; Tue, 22 Oct 2013 08:56:06 +0530 Received: from localhost.cn.ibm.com ([9.115.122.43]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id r9M3PhTY022250; Tue, 22 Oct 2013 08:56:04 +0530 From: Lei Li To: qemu-devel@nongnu.org Date: Tue, 22 Oct 2013 11:25:32 +0800 Message-Id: <1382412341-1173-9-git-send-email-lilei@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1382412341-1173-1-git-send-email-lilei@linux.vnet.ibm.com> References: <1382412341-1173-1-git-send-email-lilei@linux.vnet.ibm.com> X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13102203-2000-0000-0000-00000E34CD8F X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] X-Received-From: 122.248.162.8 Cc: aarcange@redhat.com, aliguori@us.ibm.com, Lei Li , quintela@redhat.com, mdroth@linux.vnet.ibm.com, mrhines@linux.vnet.ibm.com, lagarcia@br.ibm.com, pbonzini@redhat.com, rcj@linux.vnet.ibm.com Subject: [Qemu-devel] [PATCH 08/17] migration-local: add recv_pipefd() 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 This patch adds recv_pipefd() to receive the pipe file descriptor that passed by source process. Signed-off-by: Lei Li --- migration-local.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 64 insertions(+), 0 deletions(-) diff --git a/migration-local.c b/migration-local.c index f2871d8..ed0ae6c 100644 --- a/migration-local.c +++ b/migration-local.c @@ -218,3 +218,67 @@ static int send_pipefd(int sockfd, int pipefd) return ret; } + +/* + * Receive a pipe file descriptor from a source process + * via unix socket. + * + * Return negative value if there has been an recvmsg error or + * no fd to be received. Return 0 if the connection closed by + * source. Return file descriptor on success. + * + */ +static int recv_pipefd(int sockfd) +{ + struct msghdr msg; + struct iovec iov[1]; + ssize_t n; + int pipefd = -1; + char req[1]; + + union { + struct cmsghdr cm; + char control[CMSG_SPACE(sizeof(int))]; + } control_un; + struct cmsghdr *cmptr; + + msg.msg_control = control_un.control; + msg.msg_controllen = sizeof(control_un.control); + + msg.msg_name = NULL; + msg.msg_namelen = 0; + + iov[0].iov_base = req; + iov[0].iov_len = sizeof(req); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + if ( (n = recvmsg(sockfd, &msg, 0)) <= 0) { + fprintf(stderr, "recvmsg error: %s\n", strerror(errno)); + return n; + } + + /* req 0x01 means there is a file descriptor to receive */ + if (req[0] != 0x01) { + return pipefd; + } + + if ( (cmptr = CMSG_FIRSTHDR(&msg)) != NULL && + cmptr->cmsg_len == CMSG_LEN(sizeof(int))) { + if (cmptr->cmsg_level != SOL_SOCKET) { + DPRINTF(stderr, "control level != SOL_SOCKET\n"); + return pipefd; + } else if (cmptr->cmsg_type != SCM_RIGHTS) { + DPRINTF(stderr, "control type != SCM_RIGHTS\n"); + return pipefd; + } + /* The pipe file descriptor to be received */ + pipefd = *((int *) CMSG_DATA(cmptr)); + DPRINTF("pipefd received successfully: %d\n", pipefd); + } else { + /* Descriptor was not passed */ + DPRINTF(stderr, "pipefd was not passed\n"); + } + + return pipefd; +}