fix(daemon): preserve file ownership on writes for cs2 addons

apps/daemon/src/filesystem/operations.rs

@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use tokio::fs;
 use tracing::debug;
 
@@ -94,14 +94,24 @@ impl FileSystem {
     /// Write file contents.
     pub async fn write_file(&self, path: &str, data: &[u8]) -> Result<(), DaemonError> {
         let resolved = self.resolve(path)?;
+        let owner = resolved
+            .parent()
+            .and_then(resolve_target_ownership);
 
         // Ensure parent directory exists
         if let Some(parent) = resolved.parent() {
             fs::create_dir_all(parent).await.map_err(DaemonError::Io)?;
+            if let Some(ref owner) = owner {
+                apply_ownership_to_path_chain(parent, &owner)?;
+            }
         }
 
         debug!(path = %resolved.display(), "Writing file");
-        fs::write(&resolved, data).await.map_err(DaemonError::Io)
+        fs::write(&resolved, data).await.map_err(DaemonError::Io)?;
+        if let Some(ref owner) = owner {
+            apply_ownership(&resolved, owner.uid, owner.gid)?;
+        }
+        Ok(())
     }
 
     /// Delete files or directories.
@@ -119,6 +129,100 @@ impl FileSystem {
     }
 }
 
+#[derive(Clone, Debug)]
+struct OwnershipTarget {
+    anchor: PathBuf,
+    uid: u32,
+    gid: u32,
+}
+
+#[cfg(unix)]
+fn resolve_target_ownership(start: &Path) -> Option<OwnershipTarget> {
+    use std::os::unix::fs::MetadataExt;
+
+    let mut cursor = Some(start);
+    let mut fallback: Option<OwnershipTarget> = None;
+
+    while let Some(path) = cursor {
+        if let Ok(metadata) = std::fs::metadata(path) {
+            let candidate = OwnershipTarget {
+                anchor: path.to_path_buf(),
+                uid: metadata.uid(),
+                gid: metadata.gid(),
+            };
+
+            if fallback.is_none() {
+                fallback = Some(candidate.clone());
+            }
+
+            if candidate.uid != 0 || candidate.gid != 0 {
+                return Some(candidate);
+            }
+        }
+        cursor = path.parent();
+    }
+
+    fallback
+}
+
+#[cfg(not(unix))]
+fn resolve_target_ownership(_start: &Path) -> Option<OwnershipTarget> {
+    None
+}
+
+#[cfg(unix)]
+fn apply_ownership_to_path_chain(target: &Path, owner: &OwnershipTarget) -> Result<(), DaemonError> {
+    if !target.starts_with(&owner.anchor) {
+        return Ok(());
+    }
+
+    let mut current = owner.anchor.clone();
+    apply_ownership(&current, owner.uid, owner.gid)?;
+
+    let remainder = match target.strip_prefix(&owner.anchor) {
+        Ok(path) => path,
+        Err(_) => return Ok(()),
+    };
+
+    for component in remainder.components() {
+        current.push(component.as_os_str());
+        apply_ownership(&current, owner.uid, owner.gid)?;
+    }
+
+    Ok(())
+}
+
+#[cfg(not(unix))]
+fn apply_ownership_to_path_chain(_target: &Path, _owner: &OwnershipTarget) -> Result<(), DaemonError> {
+    Ok(())
+}
+
+#[cfg(unix)]
+fn apply_ownership(path: &Path, uid: u32, gid: u32) -> Result<(), DaemonError> {
+    use std::ffi::CString;
+    use std::os::unix::ffi::OsStrExt;
+
+    let bytes = path.as_os_str().as_bytes();
+    let c_path = CString::new(bytes).map_err(|err| {
+        DaemonError::Io(std::io::Error::new(
+            std::io::ErrorKind::InvalidInput,
+            format!("invalid path for chown: {err}"),
+        ))
+    })?;
+
+    let result = unsafe { libc::chown(c_path.as_ptr(), uid, gid) };
+    if result != 0 {
+        return Err(DaemonError::Io(std::io::Error::last_os_error()));
+    }
+
+    Ok(())
+}
+
+#[cfg(not(unix))]
+fn apply_ownership(_path: &Path, _uid: u32, _gid: u32) -> Result<(), DaemonError> {
+    Ok(())
+}
+
 #[derive(Debug, Clone)]
 pub struct FileEntry {
     pub name: String,