[client] added linked list utility

client/ll.h

@@ -0,0 +1,27 @@
+/*
+KVMGFX Client - A KVM Client for VGA Passthrough
+Copyright (C) 2017 Geoffrey McRae <geoff@hostfission.com>
+https://looking-glass.hostfission.com
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; either version 2 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <stdbool.h>
+struct ll;
+
+struct ll * ll_new();
+void        ll_free(struct ll * list);
+void        ll_push(struct ll * list, void * data);
+bool        ll_shift(struct ll * list, void ** data);
+bool        ll_peek_head(struct ll * list, void ** data);