From f625d197050d05d33172bd5e93d044155208befb Mon Sep 17 00:00:00 2001 From: "plai@redhat.com" Date: Thu, 21 Jun 2018 18:54:38 +0200 Subject: [PATCH 29/57] vhost-user: support receiving file descriptors in slave_read RH-Author: plai@redhat.com Message-id: <1529607285-9942-4-git-send-email-plai@redhat.com> Patchwork-id: 80933 O-Subject: [RHEL7.6 PATCH BZ 1526645 03/10] vhost-user: support receiving file descriptors in slave_read Bugzilla: 1526645 RH-Acked-by: Michael S. Tsirkin RH-Acked-by: Maxime Coquelin RH-Acked-by: Laurent Vivier From: Tiwei Bie Signed-off-by: Tiwei Bie Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 1f3a4519b1c107b5db2434b30638353978366b4d) Signed-off-by: Paul Lai Signed-off-by: Miroslav Rezanina --- 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; } -- 1.8.3.1