add core state management

Makefile

@@ -4,7 +4,8 @@ PACKAGE_BUGREPORT := https://github.com/kaniini/ifupdown-ng/issues/new
 
 
 INTERFACES_FILE := /etc/network/interfaces
-CFLAGS := -ggdb3 -O2 -Wall -I. -DINTERFACES_FILE=\"${INTERFACES_FILE}\" -DPACKAGE_NAME=\"${PACKAGE_NAME}\" -DPACKAGE_VERSION=\"${PACKAGE_VERSION}\" -DPACKAGE_BUGREPORT=\"${PACKAGE_BUGREPORT}\"
+STATE_FILE := /run/ifstate
+CFLAGS := -ggdb3 -O2 -Wall -I. -DINTERFACES_FILE=\"${INTERFACES_FILE}\" -DSTATE_FILE=\"${STATE_FILE}\" -DPACKAGE_NAME=\"${PACKAGE_NAME}\" -DPACKAGE_VERSION=\"${PACKAGE_VERSION}\" -DPACKAGE_BUGREPORT=\"${PACKAGE_BUGREPORT}\"
 
 
 LIBIFUPDOWN_SRC = \
@@ -13,7 +14,8 @@ LIBIFUPDOWN_SRC = \
 	libifupdown/interface.c \
 	libifupdown/interface-file.c \
 	libifupdown/fgetline.c \
-	libifupdown/version.c
+	libifupdown/version.c \
+	libifupdown/state.c
 
 LIBIFUPDOWN_OBJ = ${LIBIFUPDOWN_SRC:.c=.o}
 LIBIFUPDOWN_LIB = libifupdown.a

libifupdown/state.c

@@ -0,0 +1,48 @@
+/*
+ * libifupdown/state.h
+ * Purpose: state management
+ *
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * 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 <string.h>
+#include "libifupdown/state.h"
+
+void
+lif_state_upsert(struct lif_dict *state, const char *ifname, struct lif_interface *iface)
+{
+	lif_dict_add(state, ifname, strdup(iface->ifname));
+}
+
+void
+lif_state_delete(struct lif_dict *state, const char *ifname)
+{
+	struct lif_dict_entry *entry = lif_dict_find(state, ifname);
+
+	if (entry == NULL)
+		return;
+
+	free(entry->data);
+	lif_dict_delete_entry(state, entry);
+}
+
+void
+lif_state_write(const struct lif_dict *state, FILE *f)
+{
+	struct lif_node *iter;
+
+	LIF_DICT_FOREACH(iter, state)
+	{
+		struct lif_dict_entry *entry = iter->data;
+
+		fprintf(f, "%s=%s\n", entry->key, (const char *) entry->data);
+	}
+}

libifupdown/state.h

@@ -0,0 +1,26 @@
+/*
+ * libifupdown/state.h
+ * Purpose: state management
+ *
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * 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_STATE_H__GUARD
+#define LIBIFUPDOWN_STATE_H__GUARD
+
+#include <stdio.h>
+#include "libifupdown/interface.h"
+
+extern void lif_state_upsert(struct lif_dict *state, const char *ifname, struct lif_interface *iface);
+extern void lif_state_delete(struct lif_dict *state, const char *ifname);
+extern void lif_state_write(const struct lif_dict *state, FILE *f);
+
+#endif