net_util, virtio-devices: Move TAP register/unregister helpers

Move these helper functions into net_util so that they can be used from
code inside there.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

Cargo.lock

@@ -631,6 +631,7 @@ dependencies = [
 name = "net_util"
 version = "0.1.0"
 dependencies = [
+ "epoll",
  "lazy_static",
  "libc",
  "log 0.4.8",

net_util/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["The Chromium OS Authors"]
 
 [dependencies]
+epoll = ">=4.0.1"
 libc = "0.2.72"
 log = "0.4.8"
 net_gen = { path = "../net_gen" }

net_util/src/lib.rs

@@ -27,9 +27,8 @@ mod queue_pair;
 mod tap;
 
 use std::io::Error as IoError;
-use std::mem;
-use std::net;
-use std::os::unix::io::FromRawFd;
+use std::os::unix::io::{FromRawFd, RawFd};
+use std::{io, mem, net};
 
 pub use mac::{MacAddr, MAC_ADDR_LEN};
 pub use open_tap::{open_tap, Error as OpenTapError};
@@ -75,6 +74,34 @@ fn vnet_hdr_len() -> usize {
     std::mem::size_of::<virtio_net_hdr_v1>()
 }
 
+pub fn register_listener(
+    epoll_fd: RawFd,
+    fd: RawFd,
+    ev_type: epoll::Events,
+    data: u64,
+) -> std::result::Result<(), io::Error> {
+    epoll::ctl(
+        epoll_fd,
+        epoll::ControlOptions::EPOLL_CTL_ADD,
+        fd,
+        epoll::Event::new(ev_type, data),
+    )
+}
+
+pub fn unregister_listener(
+    epoll_fd: RawFd,
+    fd: RawFd,
+    ev_type: epoll::Events,
+    data: u64,
+) -> std::result::Result<(), io::Error> {
+    epoll::ctl(
+        epoll_fd,
+        epoll::ControlOptions::EPOLL_CTL_DEL,
+        fd,
+        epoll::Event::new(ev_type, data),
+    )
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

virtio-devices/src/net.rs

@@ -6,9 +6,9 @@
 // found in the THIRD-PARTY file.
 
 use super::net_util::{
-    build_net_config_space, build_net_config_space_with_mq, register_listener, unregister_listener,
-    CtrlVirtio, NetCtrlEpollHandler, VirtioNetConfig, KILL_EVENT, NET_EVENTS_COUNT, PAUSE_EVENT,
-    RX_QUEUE_EVENT, RX_TAP_EVENT, TX_QUEUE_EVENT,
+    build_net_config_space, build_net_config_space_with_mq, CtrlVirtio, NetCtrlEpollHandler,
+    VirtioNetConfig, KILL_EVENT, NET_EVENTS_COUNT, PAUSE_EVENT, RX_QUEUE_EVENT, RX_TAP_EVENT,
+    TX_QUEUE_EVENT,
 };
 use super::Error as DeviceError;
 use super::{
@@ -18,7 +18,10 @@ use crate::VirtioInterrupt;
 use anyhow::anyhow;
 use libc::EAGAIN;
 use libc::EFD_NONBLOCK;
-use net_util::{open_tap, MacAddr, OpenTapError, RxVirtio, Tap, TxVirtio};
+use net_util::{
+    open_tap, register_listener, unregister_listener, MacAddr, OpenTapError, RxVirtio, Tap,
+    TxVirtio,
+};
 use std::cmp;
 use std::collections::HashMap;
 use std::fs::File;

virtio-devices/src/net_util.rs

@@ -4,10 +4,9 @@
 
 use super::Error as DeviceError;
 use super::{DescriptorChain, DeviceEventT, Queue};
-use net_util::MacAddr;
+use net_util::{register_listener, MacAddr};
 use serde::ser::{Serialize, SerializeStruct, Serializer};
 use std::fs::File;
-use std::io;
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
@@ -180,34 +179,6 @@ impl CtrlVirtio {
     }
 }
 
-pub fn register_listener(
-    epoll_fd: RawFd,
-    fd: RawFd,
-    ev_type: epoll::Events,
-    data: u64,
-) -> std::result::Result<(), io::Error> {
-    epoll::ctl(
-        epoll_fd,
-        epoll::ControlOptions::EPOLL_CTL_ADD,
-        fd,
-        epoll::Event::new(ev_type, data),
-    )
-}
-
-pub fn unregister_listener(
-    epoll_fd: RawFd,
-    fd: RawFd,
-    ev_type: epoll::Events,
-    data: u64,
-) -> std::result::Result<(), io::Error> {
-    epoll::ctl(
-        epoll_fd,
-        epoll::ControlOptions::EPOLL_CTL_DEL,
-        fd,
-        epoll::Event::new(ev_type, data),
-    )
-}
-
 pub struct NetCtrlEpollHandler {
     pub mem: GuestMemoryAtomic<GuestMemoryMmap>,
     pub kill_evt: EventFd,