From fe0667b8e961464ee8856011540466f20c2e4af9 Mon Sep 17 00:00:00 2001
From: Miguel Duarte Barroso <mdbarroso@redhat.com>
Date: Tue, 3 Oct 2023 18:29:39 +0200
Subject: [PATCH] macvlan: allow specifying MAC on iface ADD

Signed-off-by: Miguel Duarte Barroso <mdbarroso@redhat.com>
---
 Cargo.toml                 |  1 +
 examples/create_macvlan.rs | 21 ++++++++++++++++-----
 src/link/add.rs            | 16 ++++++++++++----
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index a331262..92a3c1e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ netlink-proto = { default-features = false, version = "0.11" }
 nix = { version = "0.26.1", default-features = false, features = ["fs", "mount", "sched", "signal"] }
 tokio = { version = "1.0.1", features = ["rt"], optional = true}
 async-global-executor = { version = "2.0.2", optional = true }
+macaddr = "1.0"
 
 [dev-dependencies]
 env_logger = "0.10.0"
diff --git a/examples/create_macvlan.rs b/examples/create_macvlan.rs
index c0810c6..5425a8e 100644
--- a/examples/create_macvlan.rs
+++ b/examples/create_macvlan.rs
@@ -1,22 +1,31 @@
 // SPDX-License-Identifier: MIT
 
 use futures::stream::TryStreamExt;
+use macaddr::MacAddr;
 use rtnetlink::{new_connection, Error, Handle};
-use std::env;
+use std::{env, str::FromStr};
 
 #[tokio::main]
 async fn main() -> Result<(), String> {
     let args: Vec<String> = env::args().collect();
-    if args.len() != 2 {
+    if args.len() != 2 && args.len() != 3 {
         usage();
         return Ok(());
     }
     let link_name = &args[1];
+    let mac: Option<Vec<u8>> = if args.len() == 3 {
+        let mac_address_arg = (&args[2]).to_string();
+        let mac_address = MacAddr::from_str(mac_address_arg.as_str())
+            .map_err(|e| format!("{e}"))?;
+        Some(mac_address.as_bytes().into())
+    } else {
+        None
+    };
 
     let (connection, handle, _) = new_connection().unwrap();
     tokio::spawn(connection);
 
-    create_macvlan(handle, link_name.to_string())
+    create_macvlan(handle, link_name.to_string(), mac)
         .await
         .map_err(|e| format!("{e}"))
 }
@@ -24,6 +33,7 @@ async fn main() -> Result<(), String> {
 async fn create_macvlan(
     handle: Handle,
     link_name: String,
+    mac_address: Option<Vec<u8>>,
 ) -> Result<(), Error> {
     let mut links = handle.link().get().match_name(link_name.clone()).execute();
     if let Some(link) = links.try_next().await? {
@@ -31,6 +41,7 @@ async fn create_macvlan(
             "test_macvlan".into(),
             link.header.index,
             4u32, // bridge mode
+            mac_address,
         );
         request.execute().await?
     } else {
@@ -42,7 +53,7 @@ async fn create_macvlan(
 fn usage() {
     eprintln!(
         "usage:
-    cargo run --example create_macvlan -- <link name>
+    cargo run --example create_macvlan -- <link name> [mac address]
 
 Note that you need to run this program as root. Instead of running cargo as root,
 build the example normally:
@@ -51,6 +62,6 @@ build the example normally:
 
 Then find the binary in the target directory:
 
-    cd target/debug/examples ; sudo ./create_macvlan <link_name>"
+    cd target/debug/examples ; sudo ./create_macvlan <link_name> [mac address]"
     );
 }
diff --git a/src/link/add.rs b/src/link/add.rs
index d72b48e..93f3a1d 100644
--- a/src/link/add.rs
+++ b/src/link/add.rs
@@ -684,14 +684,22 @@ impl LinkAddRequest {
     /// flags from MACVLAN_MODE (netlink-packet-route/src/rtnl/constants.rs)
     ///   being: _PRIVATE, _VEPA, _BRIDGE, _PASSTHRU, _SOURCE, which can be
     /// *combined*.
-    pub fn macvlan(self, name: String, index: u32, mode: u32) -> Self {
-        self.name(name)
+    pub fn macvlan(
+        self,
+        name: String,
+        index: u32,
+        mode: u32,
+        mac_address: Option<Vec<u8>>,
+    ) -> Self {
+        let mut m = self
+            .name(name)
             .link_info(
                 InfoKind::MacVlan,
                 Some(InfoData::MacVlan(vec![InfoMacVlan::Mode(mode)])),
             )
-            .append_nla(Nla::Link(index))
-            .up()
+            .append_nla(Nla::Link(index));
+        mac_address.map(|mac| m.message_mut().nlas.push(Nla::Address(mac)));
+        m.up()
     }
 
     /// Create macvtap on a link.