add lifecycle management

Makefile

@@ -17,7 +17,8 @@ LIBIFUPDOWN_SRC = \
 	libifupdown/version.c \
 	libifupdown/state.c \
 	libifupdown/environment.c \
-	libifupdown/execute.c
+	libifupdown/execute.c \
+	libifupdown/lifecycle.c
 
 LIBIFUPDOWN_OBJ = ${LIBIFUPDOWN_SRC:.c=.o}
 LIBIFUPDOWN_LIB = libifupdown.a

libifupdown/libifupdown.h

@@ -25,5 +25,6 @@
 #include "libifupdown/state.h"
 #include "libifupdown/environment.h"
 #include "libifupdown/execute.h"
+#include "libifupdown/lifecycle.h"
 
 #endif

libifupdown/lifecycle.c

@@ -0,0 +1,215 @@
+/*
+ * libifupdown/lifecycle.c
+ * Purpose: management of interface lifecycle (bring up, takedown, reload)
+ *
+ * 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/environment.h"
+#include "libifupdown/execute.h"
+#include "libifupdown/interface.h"
+#include "libifupdown/lifecycle.h"
+#include "libifupdown/state.h"
+
+static bool
+handle_commands_for_phase(const struct lif_execute_opts *opts, char *const envp[], struct lif_interface *iface, const char *lifname, const char *phase)
+{
+	struct lif_node *iter;
+
+	(void) lifname;
+
+	LIF_DICT_FOREACH(iter, &iface->vars)
+	{
+		struct lif_dict_entry *entry = iter->data;
+
+		if (strcmp(entry->key, phase))
+			continue;
+
+		const char *cmd = entry->data;
+		if (!lif_execute_fmt(opts, envp, "%s", cmd))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+handle_pre_up(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *lifname)
+{
+	(void) opts;
+	(void) iface;
+	(void) lifname;
+
+	return true;
+}
+
+static bool
+handle_up(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *lifname)
+{
+	struct lif_node *iter;
+
+	if (!lif_execute_fmt(opts, NULL, "/sbin/ip link set up dev %s", lifname))
+		return false;
+
+	if (iface->is_loopback)
+		return true;
+
+	LIF_DICT_FOREACH(iter, &iface->vars)
+	{
+		struct lif_dict_entry *entry = iter->data;
+
+		if (strcmp(entry->key, "address"))
+			continue;
+
+		struct lif_address *addr = entry->data;
+		char addrbuf[4096];
+
+		if (!lif_address_unparse(addr, addrbuf, sizeof addrbuf, true))
+			return false;
+
+		if (!lif_execute_fmt(opts, NULL, "/sbin/ip addr add %s dev %s", addrbuf, lifname))
+			return false;
+	}
+
+	return true;
+}
+
+static bool
+handle_down(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *lifname)
+{
+	struct lif_node *iter;
+
+	if (iface->is_loopback)
+		goto skip_addresses;
+
+	LIF_DICT_FOREACH(iter, &iface->vars)
+	{
+		struct lif_dict_entry *entry = iter->data;
+
+		if (strcmp(entry->key, "address"))
+			continue;
+
+		struct lif_address *addr = entry->data;
+		char addrbuf[4096];
+
+		if (!lif_address_unparse(addr, addrbuf, sizeof addrbuf, true))
+			return false;
+
+		if (!lif_execute_fmt(opts, NULL, "/sbin/ip addr del %s dev %s", addrbuf, lifname))
+			return false;
+	}
+
+skip_addresses:
+	if (!lif_execute_fmt(opts, NULL, "/sbin/ip link set down dev %s", lifname))
+		return false;
+
+	return true;
+}
+
+static bool
+handle_post_down(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *lifname)
+{
+	(void) opts;
+	(void) iface;
+	(void) lifname;
+
+	return true;
+}
+
+bool
+lif_lifecycle_run_phase(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *phase, const char *lifname, bool up)
+{
+	char **envp = NULL;
+
+	lif_environment_push(&envp, "IFACE", iface->ifname);
+	lif_environment_push(&envp, "PHASE", phase);
+
+	/* try to provide $METHOD for ifupdown1 scripts if we can */
+	if (iface->is_loopback)
+		lif_environment_push(&envp, "METHOD", "loopback");
+	else if (iface->is_dhcp)
+		lif_environment_push(&envp, "METHOD", "dhcp");
+
+	/* same for $MODE */
+	if (up)
+		lif_environment_push(&envp, "MODE", "start");
+	else
+		lif_environment_push(&envp, "MODE", "stop");
+
+	if (!strcmp(phase, "pre-up"))
+	{
+		if (!handle_pre_up(opts, iface, lifname))
+			goto on_error;
+	}
+	else if (!strcmp(phase, "up"))
+	{
+		if (!handle_up(opts, iface, lifname))
+			goto on_error;
+	}
+	else if (!strcmp(phase, "down"))
+	{
+		if (!handle_down(opts, iface, lifname))
+			goto on_error;
+	}
+	else if (!strcmp(phase, "post-down"))
+	{
+		if (!handle_post_down(opts, iface, lifname))
+			goto on_error;
+	}
+
+	handle_commands_for_phase(opts, envp, iface, lifname, phase);
+
+	/* we should do error handling here, but ifupdown1 doesn't */
+	lif_execute_fmt(opts, envp, "run-parts /etc/network/if-%s.d", phase);
+
+	lif_environment_free(&envp);
+	return true;
+
+on_error:
+	lif_environment_free(&envp);
+	return false;
+}
+
+bool
+lif_lifecycle_run(const struct lif_execute_opts *opts, struct lif_interface *iface, struct lif_dict *state, const char *lifname, bool up)
+{
+	if (lifname == NULL)
+		lifname = iface->ifname;
+
+	if (up)
+	{
+		/* XXX: we should try to recover (take the iface down) if bringing it up fails.
+		 * but, right now neither debian ifupdown or busybox ifupdown do any recovery,
+		 * so we wont right now.
+		 */
+		if (!lif_lifecycle_run_phase(opts, iface, "pre-up", lifname, up))
+			return false;
+
+		if (!lif_lifecycle_run_phase(opts, iface, "up", lifname, up))
+			return false;
+
+		lif_state_upsert(state, lifname, iface);
+	}
+	else
+	{
+		if (!lif_lifecycle_run_phase(opts, iface, "down", lifname, up))
+			return false;
+
+		if (!lif_lifecycle_run_phase(opts, iface, "post-down", lifname, up))
+			return false;
+
+		lif_state_delete(state, lifname);
+	}
+
+	return true;
+}

libifupdown/lifecycle.h

@@ -0,0 +1,26 @@
+/*
+ * libifupdown/lifecycle.h
+ * Purpose: management of interface lifecycle (bring up, takedown, reload)
+ *
+ * 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_LIFECYCLE_H__GUARD
+#define LIBIFUPDOWN_LIFECYCLE_H__GUARD
+
+#include "libifupdown/interface.h"
+#include "libifupdown/execute.h"
+
+extern bool lif_lifecycle_run_phase(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *phase, const char *lifname, bool up);
+extern bool lif_lifecycle_run(const struct lif_execute_opts *opts, struct lif_interface *iface, struct lif_dict *state, const char *lifname, bool up);
+
+#endif
+