init: service file keyword

Solve one more issue where privilege is required to open a file and
we do not want to grant such to the service. This is the service side
of the picture, android_get_control_file() in libcutils is the client.
The file's descriptor is placed into the environment as
"ANDROID_FILE_<path>".  For socket and files where non-alpha and
non-numeric characters in the <name/path> are replaced with _.  There
was an accompanying change in android_get_control_socket() to match
in commit 'libcutils: add android_get_control_socket() test'

Add a gTest unit test for this that tests create_file and
android_get_control_file().

Test: gTest init_tests --gtest_filter=util.create_file
Bug: 32450474
Change-Id: I96eb970c707db6d51a9885873329ba1cb1f23140

1 files changed, 78 insertions, 0 deletions

diff --git a/init/descriptors.h b/init/descriptors.h
new file mode 100644
index 000000000..ff276fbc0
--- /dev/null
+++ b/init/descriptors.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+
+#ifndef _INIT_DESCRIPTORS_H
+#define _INIT_DESCRIPTORS_H
+
+#include <sys/types.h>
+
+#include <string>
+
+class DescriptorInfo {
+ public:
+  DescriptorInfo(const std::string& name, const std::string& type, uid_t uid,
+                 gid_t gid, int perm, const std::string& context);
+  virtual ~DescriptorInfo();
+
+  friend std::ostream& operator<<(std::ostream& os, const class DescriptorInfo& info);
+  bool operator==(const DescriptorInfo& other) const;
+
+  void CreateAndPublish(const std::string& globalContext) const;
+  virtual void Clean() const;
+
+ protected:
+  const std::string& name() const { return name_; }
+  const std::string& type() const { return type_; }
+  uid_t uid() const { return uid_; }
+  gid_t gid() const { return gid_; }
+  int perm() const { return perm_; }
+  const std::string& context() const { return context_; }
+
+ private:
+  std::string name_;
+  std::string type_;
+  uid_t uid_;
+  gid_t gid_;
+  int perm_;
+  std::string context_;
+
+  virtual int Create(const std::string& globalContext) const = 0;
+  virtual const std::string key() const = 0;
+};
+
+std::ostream& operator<<(std::ostream& os, const DescriptorInfo& info);
+
+class SocketInfo : public DescriptorInfo {
+ public:
+  SocketInfo(const std::string& name, const std::string& type, uid_t uid,
+             gid_t gid, int perm, const std::string& context);
+  void Clean() const override;
+ private:
+  virtual int Create(const std::string& context) const override;
+  virtual const std::string key() const override;
+};
+
+class FileInfo : public DescriptorInfo {
+ public:
+  FileInfo(const std::string& name, const std::string& type, uid_t uid,
+           gid_t gid, int perm, const std::string& context);
+ private:
+  virtual int Create(const std::string& context) const override;
+  virtual const std::string key() const override;
+};
+
+#endif