Disallow vendor and odm files for a VM

Until we finish working on Treble interfaces, this change temporarily
prevents any vendor and odm files from being used by VMs, except for
/vendor/etc/avf/microdroid/microdroid_vendor.img.

Bug: 316431494
Test: try using vendor files
Change-Id: I9ff794d558f05f0f2e51c56241ca08aecdd8c31d
diff --git a/virtualizationmanager/src/aidl.rs b/virtualizationmanager/src/aidl.rs
index 0655e5f..6ddf952 100644
--- a/virtualizationmanager/src/aidl.rs
+++ b/virtualizationmanager/src/aidl.rs
@@ -83,7 +83,7 @@
 use std::io::{BufRead, BufReader, Error, ErrorKind, Seek, SeekFrom, Write};
 use std::iter;
 use std::num::{NonZeroU16, NonZeroU32};
-use std::os::unix::io::{FromRawFd, IntoRawFd};
+use std::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd};
 use std::os::unix::raw::pid_t;
 use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex, Weak};
@@ -484,6 +484,11 @@
             .try_for_each(check_label_for_partition)
             .or_service_specific_exception(-1)?;
 
+        // Check if files for payloads and bases are NOT coming from /vendor and /odm, as they may
+        // have unstable interfaces.
+        // TODO(b/316431494): remove once Treble interfaces are stabilized.
+        check_partitions_for_files(config).or_service_specific_exception(-1)?;
+
         let kernel = maybe_clone_file(&config.kernel)?;
         let initrd = maybe_clone_file(&config.initrd)?;
 
@@ -855,6 +860,38 @@
     Ok(vm_config)
 }
 
+fn check_partition_for_file(fd: &ParcelFileDescriptor) -> Result<()> {
+    let path = format!("/proc/self/fd/{}", fd.as_raw_fd());
+    let link = fs::read_link(&path).context(format!("can't read_link {path}"))?;
+
+    // microdroid vendor image is OK
+    if cfg!(vendor_modules) && link == Path::new("/vendor/etc/avf/microdroid/microdroid_vendor.img")
+    {
+        return Ok(());
+    }
+
+    if link.starts_with("/vendor") || link.starts_with("/odm") {
+        bail!("vendor or odm file {} can't be used for VM", link.display());
+    }
+
+    Ok(())
+}
+
+fn check_partitions_for_files(config: &VirtualMachineRawConfig) -> Result<()> {
+    config
+        .disks
+        .iter()
+        .flat_map(|disk| disk.partitions.iter())
+        .filter_map(|partition| partition.image.as_ref())
+        .try_for_each(check_partition_for_file)?;
+
+    config.kernel.as_ref().map_or(Ok(()), check_partition_for_file)?;
+    config.initrd.as_ref().map_or(Ok(()), check_partition_for_file)?;
+    config.bootloader.as_ref().map_or(Ok(()), check_partition_for_file)?;
+
+    Ok(())
+}
+
 fn load_vm_payload_config_from_file(apk_file: &File, config_path: &str) -> Result<VmPayloadConfig> {
     let mut apk_zip = ZipArchive::new(apk_file)?;
     let config_file = apk_zip.by_name(config_path)?;