From 0567def931b2d7e76be44393b44a1bb9239d7406 Mon Sep 17 00:00:00 2001
From: Bo Chen <chen.bo@intel.com>
Date: Tue, 14 Feb 2023 17:10:24 -0800
Subject: [PATCH] vmm: config: Avoid closing invalid FDs from
 'test_net_parsing()'

We need to provide valid FDs while creating 'NetConfig' instances even
for unit tests. Closing invalid FDs would cause random unit test
failures.

Also, two identical 'NetConfig' instances are not allowed any more,
because it would lead to close the same FD twice. This is consistent
with the fact that a clone of a "NetConfig" instance is no
longer *equal* to the instance itself.

Fixes: #5203

Signed-off-by: Bo Chen <chen.bo@intel.com>
---
 vmm/src/config.rs | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/vmm/src/config.rs b/vmm/src/config.rs
index 03e5ba1a2..31a2df3f9 100644
--- a/vmm/src/config.rs
+++ b/vmm/src/config.rs
@@ -2351,6 +2351,17 @@ mod tests {
         Ok(())
     }
 
+    fn memfd_create(name: &std::ffi::CStr, flags: u32) -> std::result::Result<i32, std::io::Error> {
+        // SAFETY: FFI call with correct arguments
+        let res = unsafe { libc::syscall(libc::SYS_memfd_create, name.as_ptr(), flags) };
+
+        if res < 0 {
+            Err(std::io::Error::last_os_error())
+        } else {
+            Ok(res as i32)
+        }
+    }
+
     #[test]
     fn test_net_parsing() -> Result<()> {
         // mac address is random
@@ -2429,17 +2440,23 @@ mod tests {
             }
         );
 
+        let fd1 =
+            memfd_create(&std::ffi::CString::new("test_net_parsing_fd1").unwrap(), 0).unwrap();
+        let fd2 =
+            memfd_create(&std::ffi::CString::new("test_net_parsing_fd2").unwrap(), 0).unwrap();
+
         assert_eq!(
-            NetConfig::parse("mac=de:ad:be:ef:12:34,fd=[3,7],num_queues=4")?,
-            NetConfig {
-                mac: MacAddr::parse_str("de:ad:be:ef:12:34").unwrap(),
-                fds: Some(vec![3, 7]),
-                num_queues: 4,
-                id: None,
-                tap: None,
-                vhost_socket: None,
-                ..Default::default()
-            }
+            &format!(
+                "{:?}",
+                NetConfig::parse(&format!(
+                    "mac=de:ad:be:ef:12:34,fd=[{fd1},{fd2}],num_queues=4"
+                ))?
+            ),
+            &format!("NetConfig {{ tap: None, ip: 192.168.249.1, mask: 255.255.255.0, \
+                mac: MacAddr {{ bytes: [222, 173, 190, 239, 18, 52] }}, host_mac: None, mtu: None, \
+                iommu: false, num_queues: 4, queue_size: 256, vhost_user: false, vhost_socket: None, \
+                vhost_mode: Client, id: None, fds: Some([{fd1}, {fd2}]), \
+                rate_limiter_config: None, pci_segment: 0, offload_tso: true, offload_ufo: true, offload_csum: true }}")
         );
 
         Ok(())