usb_bouncer/usb_bouncer.proto

// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

syntax = "proto3";

package usb_bouncer;

import "google/protobuf/timestamp.proto";

message RuleEntry {
  // Records the last time a USB device was added and used to determine if a
  // rule is old enough to remove.
  google.protobuf.Timestamp last_used = 1;

  // Contains a list of usbguard rules. Typically only one will be present, but
  // more than one are allowed to handle the mode switching case. The format
  // is described in:
  // https://usbguard.github.io/documentation/rule-language.html
  repeated string rules = 2;
}

// For the global_db:
// The keys for each map is the `usb_bouncer::Hash` of the devpath.
//
// `RuleEntry`s are added to entries when USB devices are connected. Either
// when they are removed or when they mode switch the particular entry is
// moved from entries to trash, until they expire. This allows for aggregating
// rules across the different modes a device may go through before it reaches
// its final state.
//
// For the user_db:
// Only `entries` is used and its key is the `usb_bouncer::Hash` of the rules
// joined by '\n' characters.
message RuleDB{
  map<string, RuleEntry> entries = 1;

  // Used by the global_db only. These are for entries that might be treated as
  // rules for a mode switching device. `RuleEntry`s are moved from `entries` to
  // `trash` for a brief time. If a mode switch occurs rules will be prepended
  // to the new RuleEntry added to entries. Once sufficient time has passed to
  // determine there was no mode-switch these entries expire and are removed on
  // the next call to `usb_bouncer::EntryManager::GarbageCollect`.
  map<string, RuleEntry> trash = 2;
}