From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50157) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmKyf-00084L-OU for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VmKyW-0007zB-QH for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:13 -0500 Received: from e23smtp08.au.ibm.com ([202.81.31.141]:56220) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VmKyW-0007yi-3y for qemu-devel@nongnu.org; Fri, 29 Nov 2013 05:07:04 -0500 Received: from /spool/local by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 29 Nov 2013 20:07:01 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id B962E3578055 for ; Fri, 29 Nov 2013 21:06:58 +1100 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rAT9n0HR6881728 for ; Fri, 29 Nov 2013 20:49:01 +1100 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rATA6vk0012536 for ; Fri, 29 Nov 2013 21:06:58 +1100 From: Lei Li Date: Fri, 29 Nov 2013 18:06:17 +0800 Message-Id: <1385719584-21114-11-git-send-email-lilei@linux.vnet.ibm.com> In-Reply-To: <1385719584-21114-1-git-send-email-lilei@linux.vnet.ibm.com> References: <1385719584-21114-1-git-send-email-lilei@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 10/17] add unix_msgfd_lookup() to callback get_buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aarcange@redhat.com, Lei Li , quintela@redhat.com, mrhines@linux.vnet.ibm.com, aliguori@amazon.com, lagarcia@br.ibm.com, pbonzini@redhat.com, rcj@linux.vnet.ibm.com The control message for exchange of pipe file descriptor should be received by recvmsg, and it might be eaten to stream file by qemu_recv() when receiving by two callbacks. So this patch adds unix_msgfd_lookup() to callback get_buffer as the only one receiver, where the pipe file descriptor would be caughted. Signed-off-by: Lei Li --- migration-local.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 56 insertions(+), 3 deletions(-) diff --git a/migration-local.c b/migration-local.c index 0a41c69..76ec306 100644 --- a/migration-local.c +++ b/migration-local.c @@ -59,16 +59,69 @@ static int qemu_local_get_sockfd(void *opaque) return s->sockfd; } +static int unix_msgfd_lookup(void *opaque, struct msghdr *msg) +{ + QEMUFileLocal *s = opaque; + struct cmsghdr *cmsg; + bool found = false; + + for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) || + cmsg->cmsg_level != SOL_SOCKET || + cmsg->cmsg_type != SCM_RIGHTS) + continue; + + /* PIPE file descriptor to be received */ + s->pipefd[0] = *((int *)CMSG_DATA(cmsg)); + } + + if (s->pipefd[0] < 0) { + fprintf(stderr, "no pipe fd can be received\n"); + return found; + } + + DPRINTF("pipefd successfully received\n"); + return s->pipefd[0]; +} + static int qemu_local_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) { QEMUFileLocal *s = opaque; ssize_t len; + struct msghdr msg = { NULL, }; + struct iovec iov[1]; + union { + struct cmsghdr cmsg; + char control[CMSG_SPACE(sizeof(int))]; + } msg_control; + + iov[0].iov_base = buf; + iov[0].iov_len = size; + + msg.msg_iov = iov; + msg.msg_iovlen = 1; + msg.msg_control = &msg_control; + msg.msg_controllen = sizeof(msg_control); for (;;) { - len = qemu_recv(s->sockfd, buf, size, 0); - if (len != -1) { - break; + if (!s->pipefd_passed) { + /* + * recvmsg is called here to catch the control message for + * the exchange of PIPE file descriptor until it is received. + */ + len = recvmsg(s->sockfd, &msg, 0); + if (len != -1) { + if (unix_msgfd_lookup(s, &msg) > 0) { + s->pipefd_passed = 1; + } + break; + } + } else { + len = qemu_recv(s->sockfd, buf, size, 0); + if (len != -1) { + break; + } } if (socket_error() == EAGAIN) { -- 1.7.7.6