Make Linux ACL support optional, as it requires CGo and makes the binary less portable

1 files changed, 62 insertions, 0 deletions

diff --git a/internal/io/fs/permissions/permission_linuxacl.h b/internal/io/fs/permissions/permission_linuxacl.h
new file mode 100644
index 0000000..52dadcf
--- /dev/null
+++ b/internal/io/fs/permissions/permission_linuxacl.h
@@ -0,0 +1,62 @@
+// +build linuxacl
+
+#ifndef PERMISSION_LINUX_H
+#define PERMISSION_LINUX_H
+
+#include <acl/libacl.h>
+#include <errno.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/acl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+//#define DEBUG
+#define USER_CHECK 0
+#define GROUP_CHECK 1
+
+struct permission_checker {
+  char *user_name;
+  uid_t uid;
+  gid_t *gids;
+  int ngids;
+  char *file_path;
+  struct stat file_stat;
+  struct passwd pw;
+};
+
+
+#ifdef DEBUG
+// Print out permission_checker struct.
+void debug_print_checker(struct permission_checker *pc);
+#endif
+
+// Stat a given file to retrieve traditional UNIX permissions.
+int stat_file(struct permission_checker *pc);
+
+// Retrieve UID of user.
+int get_user_uid(struct permission_checker *pc);
+
+// Retrieve all groups of the user.
+int get_user_groups(struct permission_checker *pc);
+
+// Check whether user is member of a group or not.
+int is_member_of_group(struct permission_checker *pc, gid_t gid);
+
+// Check whether user can read file according Linux ACLs.
+// As flag use either USER_CHECK or GROUP_CHECK.
+int check_acl(struct permission_checker *pc, const int flag);
+
+// Check whether user has permissions to read file according traditional
+// UNIX permissions. As flag use either USER_CHECK or GROUP_CHECK.
+int check_traditional(struct permission_checker *pc, const int flag);
+
+// Returns 1 if user has permission to read file.
+// Returns <0 on error and returns 0 if no permissions.
+int permission_to_read(char* user, char *file_path);
+
+#endif // PERMISSION_LINUX_H