Improved code readability and added database file argument.

src/main.c

@@ -10,16 +10,15 @@
   See the file LICENSE.
 */
 
-#include <sys/types.h>
-#include <unistd.h>
 #define FUSE_USE_VERSION 31
 
 #define _GNU_SOURCE
 
 #include <fuse3/fuse.h>
-
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 #include "fuse_operations.h"
 #include "sourcefs.h"
@@ -28,15 +27,25 @@
 const char *mountpoint = NULL;
 
 int main(int argc, char *argv[]) {
+  if (argc < 3) {
+    fprintf(stderr, "Usage: icfs <FUSE arguments> [target directory] [path to "
+                    "the permanent permissions database\n");
+    return EXIT_FAILURE;
+  }
+
+  // if umask != 0, the filesystem will create files with more restrictive
+  // permissions than it's caller reqested
   umask(0);
 
-  int ret = init_ui_socket();
+  // ui socket should always be initialized before anything else, since it
+  // handles the setuid bits!
+  int ret = init_ui_socket(argv[argc - 1]);
   if (ret != 0) {
     fprintf(stderr, "Could not initalize ui-socket.\n");
     exit(EXIT_FAILURE);
   }
 
-  mountpoint = realpath(argv[argc - 1], NULL);
+  mountpoint = realpath(argv[argc - 2], NULL);
 
   ret = source_init(mountpoint);
   if (ret != 0) {
@@ -44,9 +53,9 @@ int main(int argc, char *argv[]) {
     exit(EXIT_FAILURE);
   }
 
-  ret = fuse_main(argc, argv, get_fuse_operations(), NULL);
+  ret = fuse_main(argc - 1, argv, get_fuse_operations(), NULL);
 
-  free(mountpoint);
+  free((void *)mountpoint);
   destroy_ui_socket();
   return ret;
 }