From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45984) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eSH2a-00063P-Us for qemu-devel@nongnu.org; Fri, 22 Dec 2017 01:42:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eSH2W-0007MN-NV for qemu-devel@nongnu.org; Fri, 22 Dec 2017 01:42:45 -0500 Received: from mga07.intel.com ([134.134.136.100]:46019) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eSH2W-0007Ia-Ee for qemu-devel@nongnu.org; Fri, 22 Dec 2017 01:42:40 -0500 From: Tiwei Bie Date: Fri, 22 Dec 2017 14:41:49 +0800 Message-Id: <20171222064151.29266-2-tiwei.bie@intel.com> In-Reply-To: <20171222064151.29266-1-tiwei.bie@intel.com> References: <20171222064151.29266-1-tiwei.bie@intel.com> Subject: [Qemu-devel] [RFC 1/3] vhost-user: support receiving file descriptors in slave_read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: virtio-dev@lists.oasis-open.org, qemu-devel@nongnu.org, mst@redhat.com, alex.williamson@redhat.com, pbonzini@redhat.com, stefanha@redhat.com Cc: cunming.liang@intel.com, dan.daly@intel.com, jianfeng.tan@intel.com, zhihong.wang@intel.com, xiao.w.wang@intel.com, tiwei.bie@intel.com Signed-off-by: Tiwei Bie --- hw/virtio/vhost-user.c | 40 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 093675ed98..e7108138fd 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -614,14 +614,43 @@ static void slave_read(void *opaque) struct vhost_user *u = dev->opaque; VhostUserMsg msg = { 0, }; int size, ret = 0; + struct iovec iov; + struct msghdr msgh; + int fd = -1; + size_t fdsize = sizeof(fd); + char control[CMSG_SPACE(fdsize)]; + struct cmsghdr *cmsg; + + memset(&msgh, 0, sizeof(msgh)); + msgh.msg_iov = &iov; + msgh.msg_iovlen = 1; + msgh.msg_control = control; + msgh.msg_controllen = sizeof(control); /* Read header */ - size = read(u->slave_fd, &msg, VHOST_USER_HDR_SIZE); + iov.iov_base = &msg; + iov.iov_len = VHOST_USER_HDR_SIZE; + + size = recvmsg(u->slave_fd, &msgh, 0); if (size != VHOST_USER_HDR_SIZE) { error_report("Failed to read from slave."); goto err; } + if (msgh.msg_flags & MSG_CTRUNC) { + error_report("Truncated message."); + goto err; + } + + for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL; + cmsg = CMSG_NXTHDR(&msgh, cmsg)) { + if (cmsg->cmsg_level == SOL_SOCKET && + cmsg->cmsg_type == SCM_RIGHTS) { + memcpy(&fd, CMSG_DATA(cmsg), fdsize); + break; + } + } + if (msg.size > VHOST_USER_PAYLOAD_SIZE) { error_report("Failed to read msg header." " Size %d exceeds the maximum %zu.", msg.size, @@ -642,9 +671,15 @@ static void slave_read(void *opaque) break; default: error_report("Received unexpected msg type."); + if (fd != -1) { + close(fd); + } ret = -EINVAL; } + /* Message handlers need to make sure that fd will be consumed. */ + fd = -1; + /* * REPLY_ACK feature handling. Other reply types has to be managed * directly in their request handlers. @@ -669,6 +704,9 @@ err: qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL); close(u->slave_fd); u->slave_fd = -1; + if (fd != -1) { + close(fd); + } return; } -- 2.13.3