system/core: add libpackagelistparser

There are 4 components that all implement package parsing, they are:
1. sdcardd
2. libselinux
3. logd
4. runas

Create a library that can be used by all of them, and new ones as needed.

(Moved from frameworks/base)

Change-Id: I282ec1204e592502ef3b28fedf577af824338c58

packagelistparser/packagelistparser.h

diff --git a/packagelistparser/packagelistparser.h b/packagelistparser/packagelistparser.h
new file mode 100644
index 0000000..d602c26
--- /dev/null
+++ b/packagelistparser/packagelistparser.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2015, Intel Corporation
+ * Copyright (C) 2015 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.
+ *
+ * Written by William Roberts <william.c.roberts@intel.com>
+ *
+ * This is a parser library for parsing the packages.list file generated
+ * by PackageManager service.
+ *
+ * This simple parser is sensitive to format changes in
+ * frameworks/base/services/core/java/com/android/server/pm/Settings.java
+ * A dependency note has been added to that file to correct
+ * this parser.
+ */
+
+#ifndef PACKAGELISTPARSER_H_
+#define PACKAGELISTPARSER_H_
+
+#include <stdbool.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+/** The file containing the list of installed packages on the system */
+#define PACKAGES_LIST_FILE  "/data/system/packages.list"
+
+typedef struct pkg_info pkg_info;
+typedef struct gid_list gid_list;
+
+struct gid_list {
+    size_t cnt;
+    gid_t *gids;
+};
+
+struct pkg_info {
+    char *name;
+    uid_t uid;
+    bool debuggable;
+    char *data_dir;
+    char *seinfo;
+    gid_list gids;
+    void *private_data;
+};
+
+/**
+ * Callback function to be used by packagelist_parse() routine.
+ * @param info
+ *  The parsed package information
+ * @param userdata
+ *  The supplied userdata pointer to packagelist_parse()
+ * @return
+ *  true to keep processing, false to stop.
+ */
+typedef bool (*pfn_on_package)(pkg_info *info, void *userdata);
+
+/**
+ * Parses the file specified by PACKAGES_LIST_FILE and invokes the callback on
+ * each entry found. Once the callback is invoked, ownership of the pkg_info pointer
+ * is passed to the callback routine, thus they are required to perform any cleanup
+ * desired.
+ * @param callback
+ *  The callback function called on each parsed line of the packages list.
+ * @param userdata
+ *  An optional userdata supplied pointer to pass to the callback function.
+ * @return
+ *  true on success false on failure.
+ */
+extern bool packagelist_parse(pfn_on_package callback, void *userdata);
+
+/**
+ * Frees a pkg_info structure.
+ * @param info
+ *  The struct to free
+ */
+extern void packagelist_free(pkg_info *info);
+
+__END_DECLS
+
+#endif /* PACKAGELISTPARSER_H_ */