1 files changed, 61 insertions, 0 deletions
diff --git a/cmds/idmap2/libidmap2/PolicyUtils.cpp b/cmds/idmap2/libidmap2/PolicyUtils.cpp
new file mode 100644
index 000000000000..fc5182af61c1
--- /dev/null
+++ b/cmds/idmap2/libidmap2/PolicyUtils.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "include/idmap2/PolicyUtils.h"
+
+#include <sstream>
+
+#include "android-base/strings.h"
+#include "idmap2/Policies.h"
+
+using android::idmap2::policy::kPolicyStringToFlag;
+
+namespace android::idmap2::utils {
+
+Result<PolicyBitmask> PoliciesToBitmaskResult(const std::vector<std::string>& policies) {
+  std::vector<std::string> unknown_policies;
+  PolicyBitmask bitmask = 0;
+  for (const std::string& policy : policies) {
+    const auto result = std::find_if(kPolicyStringToFlag.begin(), kPolicyStringToFlag.end(),
+                                     [policy](const auto& it) { return policy == it.first; });
+    if (result != kPolicyStringToFlag.end()) {
+      bitmask |= result->second;
+    } else {
+      unknown_policies.emplace_back(policy.empty() ? "empty" : policy);
+    }
+  }
+
+  if (unknown_policies.empty()) {
+    return Result<PolicyBitmask>(bitmask);
+  }
+
+  auto prefix = unknown_policies.size() == 1 ? "policy" : "policies";
+  return Error("unknown %s: \"%s\"", prefix, android::base::Join(unknown_policies, ",").c_str());
+}
+
+std::vector<std::string> BitmaskToPolicies(const PolicyBitmask& bitmask) {
+  std::vector<std::string> policies;
+
+  for (const auto& policy : kPolicyStringToFlag) {
+    if ((bitmask & policy.second) != 0) {
+      policies.emplace_back(policy.first.to_string());
+    }
+  }
+
+  return policies;
+}
+
+}  // namespace android::idmap2::utils