crosvm: use seqpacket rather than datagram sockets

The advantage of seqpacket is that they are connection oriented. A
listener can be created that accepts new connections, useful for the
path based VM control sockets. Previously, the only bidirectional
sockets in crosvm were either stream based or made using socketpair.

This change also whitelists sendmsg and recvmsg for the common device
policy.

TEST=cargo test
BUG=chromium:848187

Change-Id: I83fd46f54bce105a7730632cd013b5e7047db22b
Reviewed-on: https://chromium-review.googlesource.com/1470917
Commit-Ready: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/devices/src/virtio/block.rs b/devices/src/virtio/block.rs
index 9dcf828..3c5d2fd 100644
--- a/devices/src/virtio/block.rs
+++ b/devices/src/virtio/block.rs
@@ -7,7 +7,6 @@ use std::fmt::{self, Display};
 use std::io::{self, Read, Seek, SeekFrom, Write};
 use std::mem::{size_of, size_of_val};
 use std::os::unix::io::{AsRawFd, RawFd};
-use std::os::unix::net::UnixDatagram;
 use std::result;
 use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
@@ -19,8 +18,8 @@ use sync::Mutex;
 use sys_util::Error as SysError;
 use sys_util::Result as SysResult;
 use sys_util::{
-    EventFd, FileSetLen, FileSync, GuestAddress, GuestMemory, GuestMemoryError, PollContext,
-    PollToken, PunchHole, TimerFd, WriteZeroes,
+    net::UnixSeqpacket, EventFd, FileSetLen, FileSync, GuestAddress, GuestMemory, GuestMemoryError,
+    PollContext, PollToken, PunchHole, TimerFd, WriteZeroes,
 };
 
 use data_model::{DataInit, Le16, Le32, Le64};
@@ -695,7 +694,7 @@ impl<T: DiskFile> Worker<T> {
         self.interrupt_evt.write(1).unwrap();
     }
 
-    fn run(&mut self, queue_evt: EventFd, kill_evt: EventFd, control_socket: UnixDatagram) {
+    fn run(&mut self, queue_evt: EventFd, kill_evt: EventFd, control_socket: UnixSeqpacket) {
         #[derive(PollToken)]
         enum Token {
             FlushTimer,
@@ -819,7 +818,7 @@ pub struct Block<T: DiskFile> {
     disk_size: Arc<Mutex<u64>>,
     avail_features: u64,
     read_only: bool,
-    control_socket: Option<UnixDatagram>,
+    control_socket: Option<UnixSeqpacket>,
 }
 
 fn build_config_space(disk_size: u64) -> virtio_blk_config {
@@ -844,7 +843,7 @@ impl<T: DiskFile> Block<T> {
     pub fn new(
         mut disk_image: T,
         read_only: bool,
-        control_socket: Option<UnixDatagram>,
+        control_socket: Option<UnixSeqpacket>,
     ) -> SysResult<Block<T>> {
         let disk_size = disk_image.seek(SeekFrom::End(0))? as u64;
         if disk_size % SECTOR_SIZE != 0 {