From 4fc0b3e09ad892e2b2da975b6786998729511ac6 Mon Sep 17 00:00:00 2001
From: Gris Ge <fge@redhat.com>
Date: Sun, 23 Apr 2023 17:37:00 +0800
Subject: [PATCH 1/2] dep: Upgrade to nix 0.26.2

Signed-off-by: Gris Ge <fge@redhat.com>
---
 rust/src/lib/Cargo.toml         |  2 +-
 rust/src/lib/nispor/hostname.rs | 15 ++++++++-------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/rust/src/lib/Cargo.toml b/rust/src/lib/Cargo.toml
index 29fe4c34..1a4e96c4 100644
--- a/rust/src/lib/Cargo.toml
+++ b/rust/src/lib/Cargo.toml
@@ -55,7 +55,7 @@ default-features = false
 features = ["derive"]
 
 [dependencies.nix]
-version = "0.24.1"
+version = "0.26.2"
 optional = true
 default-features = false
 features = ["feature", "hostname"]
diff --git a/rust/src/lib/nispor/hostname.rs b/rust/src/lib/nispor/hostname.rs
index 517bf7c7..b96fb3f3 100644
--- a/rust/src/lib/nispor/hostname.rs
+++ b/rust/src/lib/nispor/hostname.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: Apache-2.0
+
 use std::io::Read;
 
 use crate::{ErrorKind, HostNameState, NmstateError};
@@ -5,17 +7,16 @@ use crate::{ErrorKind, HostNameState, NmstateError};
 const HOST_NAME_MAX: usize = 64;
 
 pub(crate) fn get_hostname_state() -> Option<HostNameState> {
-    let mut buffer = [0u8; HOST_NAME_MAX];
-    let running = match nix::unistd::gethostname(&mut buffer) {
-        Ok(hostname_cstr) => match hostname_cstr.to_str() {
-            Ok(h) => Some(h.to_string()),
-            Err(e) => {
-                log::error!("Failed to convert hostname to String: {}", e);
+    let running = match nix::unistd::gethostname() {
+        Ok(hostname_cstr) => match hostname_cstr.into_string() {
+            Ok(h) => Some(h),
+            Err(s) => {
+                log::error!("Failed to convert hostname to String: {:?}", s);
                 None
             }
         },
         Err(e) => {
-            log::error!("Failed to get hostname: {}", e);
+            log::error!("Failed to get hostname {}", e);
             None
         }
     };
-- 
2.40.0


From c9fd1e80d3c87e1f844edcd86e9d36ae499ce717 Mon Sep 17 00:00:00 2001
From: Gris Ge <fge@redhat.com>
Date: Sun, 23 Apr 2023 16:01:29 +0800
Subject: [PATCH 2/2] cli: Do nothing for `persist-nic-names` when got
 `net.ifnames=0`

When `net.ifnames=0` is defined in kernel argument, systemd will disable
the predicable network interface name which make no sense for nmstate to
pin the interface names. Hence we do nothing in `persist-nic-names` in
that case.

Manually tested in CentOS stream 9 VM.

Signed-off-by: Gris Ge <fge@redhat.com>
---
 rust/src/cli/persist_nic.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/rust/src/cli/persist_nic.rs b/rust/src/cli/persist_nic.rs
index 6b126d58..61b07dbb 100644
--- a/rust/src/cli/persist_nic.rs
+++ b/rust/src/cli/persist_nic.rs
@@ -7,6 +7,8 @@
 //!
 //! The logic currently is:
 //!
+//!  - Do nothing if kernel argument contains `net.ifnames=0` which disabled the
+//!    predicable network interface name, hence not fit our use case here.
 //!  - Iterate over all active NICs
 //!  - Pin every ethernet interface to its MAC address (prefer permanent MAC
 //!    address)
@@ -70,6 +72,14 @@ pub(crate) fn run_persist_immediately(
         PersistAction::CleanUpDryRun => return clean_up(root, true),
     };
 
+    if is_prediable_ifname_disabled() {
+        log::info!(
+            "Systemd predicable network interface name is disabled \
+            by kernel argument `net.ifnames=0`, will do nothing"
+        );
+        return Ok("".to_string());
+    }
+
     let stamp_path = Path::new(root)
         .join(SYSTEMD_NETWORK_LINK_FOLDER)
         .join(NMSTATE_PERSIST_STAMP);
@@ -317,3 +327,12 @@ fn is_nmstate_generated_systemd_link_file(file_path: &PathBuf) -> bool {
         .map(|_| buff == PERSIST_GENERATED_BY.as_bytes())
         .unwrap_or_default()
 }
+
+const KERNEL_CMDLINE_FILE: &str = "/proc/cmdline";
+
+fn is_prediable_ifname_disabled() -> bool {
+    std::fs::read(KERNEL_CMDLINE_FILE)
+        .map(|v| String::from_utf8(v).unwrap_or_default())
+        .map(|c| c.contains("net.ifnames=0"))
+        .unwrap_or_default()
+}
-- 
2.40.0