Improve opening of authentication file

authfile.c

@@ -33,23 +33,16 @@ enum authfile_ret authfile_load(const char *file) {
     char *auth_data = NULL;
     auth_t auth_entries[MAX_ENTRIES];
 
-    if (stat(file, &sb) == -1) {
-        return AUTHFILE_MISSING;
-    }
-
-    auth_data = calloc(1, sb.st_size);
-
-    if (auth_data == NULL) {
-        return AUTHFILE_OOM;
-    }
-
     FILE *pwfile = fopen(file, "r");
     if (pwfile == NULL) {
-        // not strictly necessary but to be safe.
-        free(auth_data);
         return AUTHFILE_OPENFAIL;
+    } else if (fstat(fileno(pwfile), &sb)) {
+        fclose(pwfile);
+        return AUTHFILE_STATFAIL;
     }
 
+    auth_data = calloc(1, sb.st_size);
+
     char *auth_cur = auth_data;
     auth_t *entry_cur = auth_entries;
     int used = 0;

authfile.h

@@ -3,8 +3,8 @@
 
 enum authfile_ret {
     AUTHFILE_OK = 0,
-    AUTHFILE_MISSING,
     AUTHFILE_OOM,
+    AUTHFILE_STATFAIL, // not likely, but just to be sure
     AUTHFILE_OPENFAIL,
     AUTHFILE_MALFORMED,
 };

memcached.c

@@ -6102,9 +6102,14 @@ int main (int argc, char **argv) {
         }
 
         switch (authfile_load(settings.auth_file)) {
-            case AUTHFILE_MISSING: // fall through.
+            case AUTHFILE_STATFAIL:
+                vperror("Could not stat authfile [%s], error %s", settings.auth_file
+                                                            , strerror(errno));
+                exit(EXIT_FAILURE);
+                break;
             case AUTHFILE_OPENFAIL:
-                vperror("Could not open authfile [%s] for reading", settings.auth_file);
+                vperror("Could not open authfile [%s] for reading, error %s", settings.auth_file
+                                                                           , strerror(errno));
                 exit(EXIT_FAILURE);
                 break;
             case AUTHFILE_OOM: