// Copyright 2024 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

syntax = "proto3";
option optimize_for = LITE_RUNTIME;

// This file defines messages used for starting vhost-user devices.
package vm_tools.vhost_user_starter;

// Defines a Uid/Gid mapping between a user namespace and the parent
// namespace. The [in_id,in_id + range] in user namespace will be mapped to
// [out_id,out_id + range] outside the user namespace(boundary is inclusive).
message IdMapItem {
  // The start of the range of IDs inside of user namespace
  uint32 in_id = 1;
  // The start of the range of IDs outside of user namespace
  uint32 out_id = 2;
  // The length of the range of user IDs that is mapped between
  // the two user namespaces
  uint32 range = 3;
}

// The options for configuring a directory to be shared with the VM through
// virtio-fs. The flags respondes to the --cfg parameter for "crosvm device fs"
// command. For detailed information for each option, refer to the following
// code: chromiumos/src/platform/crosvm/devices/src/virtio/fs/config.rs
message VhostUserVirtioFsConfig {
  // Indicates whether the VM can cache the contents of the shared directory.
  // Valid value is either (never, auto, always).
  string cache = 1;
  // How long the VM should consider file attributes and directory entries to be
  // valid(seconds).
  uint32 timeout = 2;
  // Controls whether security.* xattrs (except for security.selinux) are
  // re-written.
  bool rewrite_security_xattrs = 3;
  // Whether to use case-insensitive lookups for directory entries (ASCII only).
  bool ascii_casefold = 4;
  // Enables writeback caching This is safe to set true only when the VM has
  // exclusive access to the files in a directory.
  bool writeback = 5;
  // Whether to enable support for POSIX ACLs.
  bool posix_acl = 6;
  // How long the FUSE client can cache negative lookup results(seconds).
  uint32 negative_timeout = 7;
  // UIDs which are privileged to perform quota-related operations.
  repeated uint32 privileged_quota_uids = 8;
  // Number of times guest can call FS_IOC_SETPERMISSION ioctl. Set to 0 if not
  // used. See go/remove-mount-passthrough-fuse for the number.
  uint32 max_dynamic_perm = 9;
  // Number of times guest can call FS_IOC_SETPATHXATTR ioctl. Set to 0 if not
  // used. See go/remove-mount-passthrough-fuse for the number.
  uint32 max_dynamic_xattr = 10;
}

// Encodes all information excepting socket-fd to start a vhost-user
// virtio-fs device. Each field is a parameter of vhost-user fs deivice,
// refer to https://crosvm.dev/book/devices/fs.html  for details.
message StartVhostUserFsRequest {
  // The path of host shared directory
  string shared_dir = 1;

  // The tag of vhost-user virtio-fs device
  string tag = 2;

  // The uid map used in minijail
  repeated IdMapItem uid_map = 3;

  // The gid map used in minijail
  repeated IdMapItem gid_map = 4;

  // The uid of the device process in the new user namespace created.
  // Default value is 0 if not set
  optional uint32 uid = 5;

  // The gid of device process in the new user namespace created.
  // Default value is 0 if not set
  optional uint32 gid = 6;

  // virtio-fs config option for the device process
  VhostUserVirtioFsConfig cfg = 7;

  // The tag used for syslog
  string syslog_tag = 8;
}

message StartVhostUserFsResponse {}