Fix/dbus call issue

crates/libcgroups/src/systemd/dbus_native/dbus.rs

@@ -4,6 +4,7 @@ use std::os::fd::AsRawFd;
 use std::path::PathBuf;
 use std::sync::atomic::{AtomicU32, Ordering};
 
+use nix::errno::Errno;
 use nix::sys::socket;
 
 use super::client::SystemdClient;
@@ -228,9 +229,10 @@ impl DbusConnection {
             .filter(|m| m.preamble.mtype == MessageType::MethodReturn)
             .collect();
 
-        let res = res.first().ok_or(DbusError::MethodCallErr(
-            "expected method call to have reply, found no reply message".into(),
-        ))?;
+        let res = res.first().ok_or(DbusError::AuthenticationErr(format!(
+            "expected Hello call to have reply, found no reply message, got {:?} instead",
+            res
+        )))?;
         let mut ctr = 0;
         let id = String::deserialize(&res.body, &mut ctr)?;
         self.id = Some(id);
@@ -247,13 +249,18 @@ impl DbusConnection {
             let mut reply: [u8; REPLY_BUF_SIZE] = [0_u8; REPLY_BUF_SIZE];
             let mut reply_buffer = [IoSliceMut::new(&mut reply[0..])];
 
-            let reply_rcvd = socket::recvmsg::<()>(
+            let reply_res = socket::recvmsg::<()>(
                 self.socket,
                 &mut reply_buffer,
                 None,
                 socket::MsgFlags::empty(),
-            )?;
+            );
 
+            let reply_rcvd = match reply_res {
+                Ok(msg) => msg,
+                Err(Errno::EAGAIN) => continue,
+                Err(e) => return Err(e.into()),
+            };
             let received_byte_count = reply_rcvd.bytes;
 
             ret.extend_from_slice(&reply[0..received_byte_count]);
@@ -296,20 +303,47 @@ impl DbusConnection {
             None,
         )?;
 
-        let reply = self.receive_complete_response()?;
-
-        // note that a single received response can contain multiple
-        // messages, so we must deserialize it piece by piece
         let mut ret = Vec::new();
-        let mut buf = &reply[..];
-
-        while !buf.is_empty() {
-            let mut ctr = 0;
-            let msg = Message::deserialize(&buf[ctr..], &mut ctr)?;
-            // we reset the buf, because I couldn't figure out how the adjust_counter function
-            // should should be changed to work correctly with non-zero start counter, and this solved that issue
-            buf = &buf[ctr..];
-            ret.push(msg);
+
+        // it is possible that while receiving messages, we get some extra/previous message
+        // for method calls, we need to have an error or method return type message, so
+        // we keep looping until we get either of these. see https://github.com/containers/youki/issues/2826
+        // for more detailed analysis.
+        loop {
+            let reply = self.receive_complete_response()?;
+
+            // note that a single received response can contain multiple
+            // messages, so we must deserialize it piece by piece
+            let mut buf = &reply[..];
+
+            while !buf.is_empty() {
+                let mut ctr = 0;
+                let msg = Message::deserialize(&buf[ctr..], &mut ctr)?;
+                // we reset the buf, because I couldn't figure out how the adjust_counter function
+                // should should be changed to work correctly with non-zero start counter, and this solved that issue
+                buf = &buf[ctr..];
+                ret.push(msg);
+            }
+
+            // in Youki, we only ever do method call apart from initial auth
+            // in case it is, we don't really have a specific message to look
+            // out of, so we take the buffer and break
+            if mtype != MessageType::MethodCall {
+                break;
+            }
+
+            // check if any of the received message is method return or error type
+            let return_message_count = ret
+                .iter()
+                .filter(|m| {
+                    m.preamble.mtype == MessageType::MethodReturn
+                        || m.preamble.mtype == MessageType::Error
+                })
+                .count();
+
+            if return_message_count > 0 {
+                break;
+            }
         }
         Ok(ret)
     }

crates/libcgroups/src/systemd/dbus_native/message.rs

@@ -54,7 +54,7 @@ impl HeaderSignature {
 }
 
 /// Type of message
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum MessageType {
     MethodCall,
     MethodReturn,

crates/libcgroups/src/systemd/dbus_native/proxy.rs

@@ -47,6 +47,7 @@ impl<'conn> Proxy<'conn> {
         member: &str,
         body: Option<Body>,
     ) -> Result<Output> {
+        tracing::trace!("dbus call at interface {} member {}", interface, member);
         let mut headers = Vec::with_capacity(4);
 
         // create necessary headers
@@ -114,9 +115,10 @@ impl<'conn> Proxy<'conn> {
         // we are only going to consider first reply, cause... so.
         // realistically there should only be at most one method return type of message
         // for a method call
-        let reply = reply.first().ok_or(DbusError::MethodCallErr(
-            "expected to get a reply for method call, didn't get any".into(),
-        ))?;
+        let reply = reply.first().ok_or(DbusError::MethodCallErr(format!(
+            "expected to get a reply for method call, got {:?} instead",
+            reply_messages
+        )))?;
 
         let headers = &reply.headers;
         let expected_signature = Output::get_signature();

crates/libcontainer/src/container/builder_impl.rs

@@ -159,7 +159,7 @@ impl ContainerBuilderImpl {
         let (init_pid, need_to_clean_up_intel_rdt_dir) =
             process::container_main_process::container_main_process(&container_args).map_err(
                 |err| {
-                    tracing::error!(?err, "failed to run container process");
+                    tracing::error!("failed to run container process {}", err);
                     LibcontainerError::MainProcess(err)
                 },
             )?;

crates/libcontainer/src/process/channel.rs

@@ -24,6 +24,8 @@ pub enum ChannelError {
     MissingSeccompFds,
     #[error("exec process failed with error {0}")]
     ExecError(String),
+    #[error("intermediate process error {0}")]
+    OtherError(String),
 }
 
 /// Channel Design
@@ -83,6 +85,11 @@ impl MainSender {
         Ok(())
     }
 
+    pub fn send_error(&mut self, err: String) -> Result<(), ChannelError> {
+        self.sender.send(Message::OtherError(err))?;
+        Ok(())
+    }
+
     pub fn close(&self) -> Result<(), ChannelError> {
         self.sender.close()?;
 
@@ -110,6 +117,7 @@ impl MainReceiver {
         match msg {
             Message::IntermediateReady(pid) => Ok(Pid::from_raw(pid)),
             Message::ExecFailed(err) => Err(ChannelError::ExecError(err)),
+            Message::OtherError(err) => Err(ChannelError::OtherError(err)),
             msg => Err(ChannelError::UnexpectedMessage {
                 expected: Message::IntermediateReady(0),
                 received: msg,

crates/libcontainer/src/process/container_main_process.rs

@@ -62,7 +62,17 @@ pub fn container_main_process(container_args: &ContainerArgs) -> Result<(Pid, bo
             ) {
                 Ok(_) => 0,
                 Err(err) => {
-                    tracing::error!(?err, "failed to run intermediate process");
+                    tracing::error!("failed to run intermediate process {}", err);
+                    match main_sender.send_error(err.to_string()) {
+                        Ok(_) => {}
+                        Err(e) => {
+                            tracing::error!(
+                                "error in sending intermediate error message {} to main: {}",
+                                err,
+                                e
+                            )
+                        }
+                    }
                     -1
                 }
             }

crates/libcontainer/src/process/message.rs

@@ -12,6 +12,7 @@ pub enum Message {
     SeccompNotify,
     SeccompNotifyDone,
     ExecFailed(String),
+    OtherError(String),
 }
 
 impl fmt::Display for Message {
@@ -24,6 +25,7 @@ impl fmt::Display for Message {
             Message::SeccompNotify => write!(f, "SeccompNotify"),
             Message::SeccompNotifyDone => write!(f, "SeccompNotifyDone"),
             Message::ExecFailed(s) => write!(f, "ExecFailed({})", s),
+            Message::OtherError(s) => write!(f, "OtherError({})", s),
         }
     }
 }