From d96f579d7f01afc2a6743287792c7b87bb33542a Mon Sep 17 00:00:00 2001
From: Maximilian Wilhelm <max@sdn.clinic>
Date: Sun, 18 Oct 2020 03:19:28 +0200
Subject: [PATCH] Introduce an compatibility layer which is empty for now.

Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>
---
 Makefile                  |  3 ++-
 cmd/ifupdown.c            |  6 ++++++
 libifupdown/compat.c      | 27 +++++++++++++++++++++++++++
 libifupdown/compat.h      | 23 +++++++++++++++++++++++
 libifupdown/libifupdown.h |  1 +
 5 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 libifupdown/compat.c
 create mode 100644 libifupdown/compat.h

diff --git a/Makefile b/Makefile
index a87ef80..a362e75 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,8 @@ LIBIFUPDOWN_SRC = \
 	libifupdown/execute.c \
 	libifupdown/lifecycle.c \
 	libifupdown/config-parser.c \
-	libifupdown/config-file.c
+	libifupdown/config-file.c \
+	libifupdown/compat.c \
 
 LIBIFUPDOWN_OBJ = ${LIBIFUPDOWN_SRC:.c=.o}
 LIBIFUPDOWN_LIB = libifupdown.a
diff --git a/cmd/ifupdown.c b/cmd/ifupdown.c
index 1edc2d0..da133c2 100644
--- a/cmd/ifupdown.c
+++ b/cmd/ifupdown.c
@@ -261,6 +261,12 @@ ifupdown_main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if(!lif_compat_apply(&collection))
+	{
+		fprintf(stderr, "%s: failed to apply compatibility glue\n", argv0);
+		return EXIT_FAILURE;
+	}
+
 	if (!lif_state_sync(&state, &collection))
 	{
 		fprintf(stderr, "%s: could not sync state\n", argv0);
diff --git a/libifupdown/compat.c b/libifupdown/compat.c
new file mode 100644
index 0000000..10a16d7
--- /dev/null
+++ b/libifupdown/compat.c
@@ -0,0 +1,27 @@
+/*
+ * libifupdown/compat.c
+ * Purpose: compatiblity glue to other implementations
+ *
+ * Copyright (c) 2020 Maximilian Wilhelm <max@sdn.clinic>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <stdbool.h>
+#include "libifupdown/dict.h"
+
+extern bool
+lif_compat_apply(struct lif_dict *collection)
+{
+	(void) collection;
+
+	/* Mangle interfaces according to some config options here */
+
+	return true;
+}
diff --git a/libifupdown/compat.h b/libifupdown/compat.h
new file mode 100644
index 0000000..ebb668b
--- /dev/null
+++ b/libifupdown/compat.h
@@ -0,0 +1,23 @@
+/*
+ * libifupdown/compat.h
+ * Purpose: compatiblity glue to other implementations
+ *
+ * Copyright (c) 2020 Maximilian Wilhelm <max@sdn.clinic>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#ifndef LIBIFUPDOWN__COMPAT_H
+#define LIBIFUPDOWN__COMPAT_H
+
+#include "libifupdown/config-file.h"
+
+extern bool lif_compat_apply (struct lif_dict *collection);
+
+#endif
diff --git a/libifupdown/libifupdown.h b/libifupdown/libifupdown.h
index 6459c6a..823adb0 100644
--- a/libifupdown/libifupdown.h
+++ b/libifupdown/libifupdown.h
@@ -29,6 +29,7 @@
 #include "libifupdown/tokenize.h"
 #include "libifupdown/config-file.h"
 #include "libifupdown/config-parser.h"
+#include "libifupdown/compat.h"
 
 #ifndef ARRAY_SIZE
 # define ARRAY_SIZE(x)   (sizeof(x) / sizeof(*x))