ethtool: Add link mode support

Some information of `ethtool <nic_name>` is from link mode, like link
speed, duplex mode and etc.

Example code and integration test case included.

Signed-off-by: Gris Ge <cnfourt@gmail.com>

ethtool/examples/dump_link_mode.rs

@@ -0,0 +1,29 @@
+use ethtool;
+use futures::stream::TryStreamExt;
+use tokio;
+
+// Once we find a way to load netsimdev kernel module in CI, we can convert this
+// to a test
+fn main() {
+    let rt = tokio::runtime::Builder::new_current_thread()
+        .enable_io()
+        .build()
+        .unwrap();
+    rt.block_on(get_link_mode(None));
+}
+
+async fn get_link_mode(iface_name: Option<&str>) {
+    let (connection, mut handle, _) = ethtool::new_connection().unwrap();
+    tokio::spawn(connection);
+
+    let mut link_mode_handle = handle.link_mode().get(iface_name).execute().await;
+
+    let mut msgs = Vec::new();
+    while let Some(msg) = link_mode_handle.try_next().await.unwrap() {
+        msgs.push(msg);
+    }
+    assert!(msgs.len() > 0);
+    for msg in msgs {
+        println!("{:?}", msg);
+    }
+}

ethtool/src/feature/get.rs

@@ -1,8 +1,7 @@
-use futures::{self, future::Either, FutureExt, StreamExt, TryStream};
-use netlink_packet_core::{NetlinkMessage, NLM_F_ACK, NLM_F_DUMP, NLM_F_REQUEST};
+use futures::TryStream;
 use netlink_packet_generic::GenlMessage;
 
-use crate::{try_ethtool, EthtoolError, EthtoolHandle, EthtoolMessage};
+use crate::{ethtool_execute, EthtoolError, EthtoolHandle, EthtoolMessage};
 
 pub struct EthtoolFeatureGetRequest {
     handle: EthtoolHandle,
@@ -25,28 +24,7 @@ impl EthtoolFeatureGetRequest {
             iface_name,
         } = self;
 
-        let nl_header_flags = match iface_name {
-            // The NLM_F_ACK is required due to bug of kernel:
-            //  https://bugzilla.redhat.com/show_bug.cgi?id=1953847
-            // without `NLM_F_MULTI`, rust-netlink will not parse
-            // multiple netlink message in single socket reply.
-            // Using NLM_F_ACK will force rust-netlink to parse all till
-            // acked at the end.
-            None => NLM_F_DUMP | NLM_F_REQUEST | NLM_F_ACK,
-            Some(_) => NLM_F_REQUEST,
-        };
-
         let ethtool_msg = EthtoolMessage::new_feature_get(iface_name.as_deref());
-
-        let mut nl_msg = NetlinkMessage::from(GenlMessage::from_payload(ethtool_msg));
-
-        nl_msg.header.flags = nl_header_flags;
-
-        match handle.request(nl_msg).await {
-            Ok(response) => Either::Left(response.map(move |msg| Ok(try_ethtool!(msg)))),
-            Err(e) => Either::Right(
-                futures::future::err::<GenlMessage<EthtoolMessage>, EthtoolError>(e).into_stream(),
-            ),
-        }
+        ethtool_execute(&mut handle, iface_name.is_none(), ethtool_msg).await
     }
 }

ethtool/src/handle.rs

@@ -1,10 +1,17 @@
-use futures::Stream;
+use futures::{future::Either, FutureExt, Stream, StreamExt, TryStream};
 use genetlink::GenetlinkHandle;
-use netlink_packet_core::NetlinkMessage;
+use netlink_packet_core::{NetlinkMessage, NLM_F_ACK, NLM_F_DUMP, NLM_F_REQUEST};
 use netlink_packet_generic::GenlMessage;
 use netlink_packet_utils::DecodeError;
 
-use crate::{EthtoolError, EthtoolFeatureHandle, EthtoolMessage, EthtoolPauseHandle};
+use crate::{
+    try_ethtool,
+    EthtoolError,
+    EthtoolFeatureHandle,
+    EthtoolLinkModeHandle,
+    EthtoolMessage,
+    EthtoolPauseHandle,
+};
 
 #[derive(Clone, Debug)]
 pub struct EthtoolHandle {
@@ -24,6 +31,10 @@ impl EthtoolHandle {
         EthtoolFeatureHandle::new(self.clone())
     }
 
+    pub fn link_mode(&mut self) -> EthtoolLinkModeHandle {
+        EthtoolLinkModeHandle::new(self.clone())
+    }
+
     pub async fn request(
         &mut self,
         message: NetlinkMessage<GenlMessage<EthtoolMessage>>,
@@ -37,3 +48,32 @@ impl EthtoolHandle {
             .map_err(|e| EthtoolError::RequestFailed(format!("BUG: Request failed with {}", e)))
     }
 }
+
+pub(crate) async fn ethtool_execute(
+    handle: &mut EthtoolHandle,
+    is_dump: bool,
+    ethtool_msg: EthtoolMessage,
+) -> impl TryStream<Ok = GenlMessage<EthtoolMessage>, Error = EthtoolError> {
+    let nl_header_flags = if is_dump {
+        // The NLM_F_ACK is required due to bug of kernel:
+        //  https://bugzilla.redhat.com/show_bug.cgi?id=1953847
+        // without `NLM_F_MULTI`, rust-netlink will not parse
+        // multiple netlink message in single socket reply.
+        // Using NLM_F_ACK will force rust-netlink to parse all till
+        // acked at the end.
+        NLM_F_DUMP | NLM_F_REQUEST | NLM_F_ACK
+    } else {
+        NLM_F_REQUEST
+    };
+
+    let mut nl_msg = NetlinkMessage::from(GenlMessage::from_payload(ethtool_msg));
+
+    nl_msg.header.flags = nl_header_flags;
+
+    match handle.request(nl_msg).await {
+        Ok(response) => Either::Left(response.map(move |msg| Ok(try_ethtool!(msg)))),
+        Err(e) => Either::Right(
+            futures::future::err::<GenlMessage<EthtoolMessage>, EthtoolError>(e).into_stream(),
+        ),
+    }
+}

ethtool/src/header.rs

@@ -3,7 +3,7 @@ use std::ffi::CString;
 use anyhow::Context;
 use byteorder::{ByteOrder, NativeEndian};
 use netlink_packet_utils::{
-    nla::{self, DefaultNla, NlaBuffer},
+    nla::{DefaultNla, Nla, NlaBuffer},
     parsers::{parse_string, parse_u32},
     DecodeError,
     Parseable,
@@ -22,7 +22,7 @@ pub enum EthtoolHeader {
     Other(DefaultNla),
 }
 
-impl nla::Nla for EthtoolHeader {
+impl Nla for EthtoolHeader {
     fn value_len(&self) -> usize {
         match self {
             Self::DevIndex(_) | Self::Flags(_) => 4,

ethtool/src/lib.rs

@@ -3,6 +3,7 @@ mod error;
 mod feature;
 mod handle;
 mod header;
+mod link_mode;
 mod macros;
 mod message;
 mod pause;
@@ -17,10 +18,18 @@ pub use feature::{
 };
 pub use handle::EthtoolHandle;
 pub use header::EthtoolHeader;
+pub use link_mode::{
+    EthtoolLinkModeAttr,
+    EthtoolLinkModeDuplex,
+    EthtoolLinkModeGetRequest,
+    EthtoolLinkModeHandle,
+};
 pub use message::{EthtoolAttr, EthtoolCmd, EthtoolMessage};
 pub use pause::{
     EthtoolPauseAttr,
     EthtoolPauseGetRequest,
     EthtoolPauseHandle,
     EthtoolPauseStatAttr,
 };
+
+pub(crate) use handle::ethtool_execute;