From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48884) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLUyr-0001ly-Jw for qemu-devel@nongnu.org; Wed, 23 May 2018 10:43:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fLUyq-0000nl-MG for qemu-devel@nongnu.org; Wed, 23 May 2018 10:43:09 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:38600 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fLUyq-0000nf-Gb for qemu-devel@nongnu.org; Wed, 23 May 2018 10:43:08 -0400 Date: Wed, 23 May 2018 17:43:07 +0300 From: "Michael S. Tsirkin" Message-ID: <1527086545-68024-14-git-send-email-mst@redhat.com> References: <1527086545-68024-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1527086545-68024-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 13/28] vhost-user: support receiving file descriptors in slave_read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Tiwei Bie From: Tiwei Bie Signed-off-by: Tiwei Bie Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/vhost-user.c | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 38da869..85d8fd2 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -852,14 +852,44 @@ static void slave_read(void *opaque) VhostUserHeader hdr = { 0, }; VhostUserPayload payload = { 0, }; int size, ret = 0; + struct iovec iov; + struct msghdr msgh; + int fd = -1; + char control[CMSG_SPACE(sizeof(fd))]; + struct cmsghdr *cmsg; + size_t fdsize; + + 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, &hdr, VHOST_USER_HDR_SIZE); + iov.iov_base = &hdr; + 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) { + fdsize = cmsg->cmsg_len - CMSG_LEN(0); + memcpy(&fd, CMSG_DATA(cmsg), fdsize); + break; + } + } + if (hdr.size > VHOST_USER_PAYLOAD_SIZE) { error_report("Failed to read msg header." " Size %d exceeds the maximum %zu.", hdr.size, @@ -883,9 +913,15 @@ 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. @@ -918,6 +954,9 @@ 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; } -- MST