Add file access tests using effective UID/GID (20.08)

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Added
 - Add function to get duplicated hosts from the hosts list. [#387](https://github.com/greenbone/gvm-libs/pull/387)
+- Add file access tests using effective UID/GID [#422](https://github.com/greenbone/gvm-libs/pull/422)
 
 ### Changed
 - Reduce ping timeout when using test_alive_hosts_only feature. [#400](https://github.com/greenbone/gvm-libs/pull/400)

util/fileutils.c

@@ -63,6 +63,60 @@ gvm_file_check_is_dir (const char *name)
   return S_ISDIR (sb.st_mode);
 }
 
+/**
+ * @brief Checks whether a file or directory exists.
+ *
+ * Unlike g_file_test this checks the permissions based on the effective
+ *  UID and GID instead of the real one.
+ *
+ * Symbolic links are followed.
+ *
+ * @param[in]  name  Name of file or directory.
+ *
+ * @return 1 if file exists, 0 if it is not.
+ */
+int
+gvm_file_exists (const char *name)
+{
+  return eaccess (name, F_OK) == 0;
+}
+
+/**
+ * @brief Checks whether a file or directory exists and is executable.
+ *
+ * Unlike g_file_test this checks the permissions based on the effective
+ *  UID and GID instead of the real one.
+ *
+ * Symbolic links are followed.
+ *
+ * @param[in]  name  Name of file or directory.
+ *
+ * @return 1 if file is executable, 0 if it is not.
+ */
+int
+gvm_file_is_executable (const char *name)
+{
+  return eaccess (name, X_OK) == 0;
+}
+
+/**
+ * @brief Checks whether a file or directory exists and is readable.
+ *
+ * Unlike g_file_test this checks the permissions based on the effective
+ *  UID and GID instead of the real one.
+ *
+ * Symbolic links are followed.
+ *
+ * @param[in]  name  Name of file or directory.
+ *
+ * @return 1 if file is readable, 0 if it is not.
+ */
+int
+gvm_file_is_readable (const char *name)
+{
+  return eaccess (name, R_OK) == 0;
+}
+
 /**
  * @brief Recursively removes files and directories.
  *

util/fileutils.h

@@ -29,6 +29,15 @@
 
 #include <glib.h>
 
+int
+gvm_file_exists (const char *name);
+
+int
+gvm_file_is_executable (const char *name);
+
+int
+gvm_file_is_readable (const char *name);
+
 int
 gvm_file_check_is_dir (const char *name);