Merge pull request #72 from ifupdown-ng/feature/depgraph-rdepends

dependency graph: reverse-dependency coloring

cmd/ifquery.c

@@ -67,9 +67,9 @@ print_interface_dot(struct lif_dict *collection, struct lif_interface *iface, st
 		return;
 
 	if (parent != NULL)
-		printf("\"%s\" -> ", parent->ifname);
+		printf("\"%s (%zu)\" -> ", parent->ifname, parent->rdepends_count);
 
-	printf("\"%s\"", iface->ifname);
+	printf("\"%s (%zu)\"", iface->ifname, iface->rdepends_count);
 
 	printf("\n");
 
@@ -290,6 +290,12 @@ ifquery_main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if (lif_lifecycle_count_rdepends(&exec_opts, &collection) == -1)
+	{
+		fprintf(stderr, "%s: could not validate dependency tree\n", argv0);
+		return EXIT_FAILURE;
+	}
+
 	/* --list --state is not allowed */
 	if (listing && listing_stat)
 		generic_usage(self_applet, EXIT_FAILURE);

cmd/ifupdown.c

@@ -101,15 +101,17 @@ skip_interface(struct lif_interface *iface, const char *ifname)
 
 	if (up && iface->refcount > 0)
 	{
-		fprintf(stderr, "%s: skipping %s (already configured), use --force to force configuration\n",
-			argv0, ifname);
+		if (exec_opts.verbose)
+			fprintf(stderr, "%s: skipping auto interface %s (already configured), use --force to force configuration\n",
+				argv0, ifname);
 		return true;
 	}
 
 	if (!up && iface->refcount == 0)
 	{
-		fprintf(stderr, "%s: skipping %s (already deconfigured), use --force to force deconfiguration\n",
-			argv0, ifname);
+		if (exec_opts.verbose)
+			fprintf(stderr, "%s: skipping auto interface %s (already deconfigured), use --force to force deconfiguration\n",
+				argv0, ifname);
 		return true;
 	}
 
@@ -229,6 +231,12 @@ ifupdown_main(int argc, char *argv[])
 		return EXIT_FAILURE;
 	}
 
+	if (lif_lifecycle_count_rdepends(&exec_opts, &collection) == -1)
+	{
+		fprintf(stderr, "%s: could not validate dependency tree\n", argv0);
+		return EXIT_FAILURE;
+	}
+
 	if (!lif_state_sync(&state, &collection))
 	{
 		fprintf(stderr, "%s: could not sync state\n", argv0);

libifupdown/interface.h

@@ -53,7 +53,8 @@ struct lif_interface {
 
 	struct lif_dict vars;
 
-	size_t refcount;	/* >= 0 if up, else 0 */
+	size_t refcount;	/* > 0 if up, else 0 */
+	size_t rdepends_count;	/* > 0 if any reverse dependency */
 };
 
 #define LIF_INTERFACE_COLLECTION_FOREACH(iter, collection) \

libifupdown/lifecycle.c

@@ -339,9 +339,6 @@ lif_lifecycle_run(const struct lif_execute_opts *opts, struct lif_interface *ifa
 	if (lifname == NULL)
 		lifname = iface->ifname;
 
-	if (!lif_lifecycle_query_dependents(opts, iface, lifname))
-		return false;
-
 	if (up)
 	{
 		/* when going up, dependents go up first. */
@@ -389,3 +386,102 @@ lif_lifecycle_run(const struct lif_execute_opts *opts, struct lif_interface *ifa
 
 	return true;
 }
+
+static bool
+count_interface_rdepends(const struct lif_execute_opts *opts, struct lif_dict *collection, struct lif_interface *parent, size_t depth)
+{
+	/* query our dependents if we don't have them already */
+	if (!lif_lifecycle_query_dependents(opts, parent, parent->ifname))
+		return false;
+
+	/* set rdepends_count to depth, dependents will be depth + 1 */
+	parent->rdepends_count = depth;
+
+	struct lif_dict_entry *requires = lif_dict_find(&parent->vars, "requires");
+
+	/* no dependents, nothing to worry about */
+	if (requires == NULL)
+		return true;
+
+	/* walk any dependents */
+	char require_ifs[4096] = {};
+	strlcpy(require_ifs, requires->data, sizeof require_ifs);
+	char *bufp = require_ifs;
+
+	for (char *tokenp = lif_next_token(&bufp); *tokenp; tokenp = lif_next_token(&bufp))
+	{
+		struct lif_interface *iface = lif_interface_collection_find(collection, tokenp);
+
+		if (!count_interface_rdepends(opts, collection, iface, depth + 1))
+			return false;
+	}
+
+	return true;
+}
+
+ssize_t
+lif_lifecycle_count_rdepends(const struct lif_execute_opts *opts, struct lif_dict *collection)
+{
+	struct lif_node *iter;
+
+	LIF_DICT_FOREACH(iter, collection)
+	{
+		struct lif_dict_entry *entry = iter->data;
+		struct lif_interface *iface = entry->data;
+
+		/* start depth at interface's rdepends_count, which will be 0 for the root,
+		 * but will be more if additional rdepends are found...
+		 */
+		if (!count_interface_rdepends(opts, collection, iface, iface->rdepends_count))
+		{
+			fprintf(stderr, "ifupdown: dependency graph is broken for interface %s\n", iface->ifname);
+			return -1;
+		}
+	}
+
+	/* figure out the max depth */
+	size_t maxdepth = 0;
+
+	LIF_DICT_FOREACH(iter, collection)
+	{
+		struct lif_dict_entry *entry = iter->data;
+		struct lif_interface *iface = entry->data;
+
+		if (iface->rdepends_count > maxdepth)
+			maxdepth = iface->rdepends_count;
+	}
+
+	/* move the collection to a temporary list so we can reorder it */
+	struct lif_list temp_list = {};
+	struct lif_node *iter_next;
+
+	LIF_LIST_FOREACH_SAFE(iter, iter_next, collection->list.head)
+	{
+		void *data = iter->data;
+
+		lif_node_delete(iter, &collection->list);
+		memset(iter, 0, sizeof *iter);
+
+		lif_node_insert(iter, data, &temp_list);
+	}
+
+	/* walk backwards from maxdepth to 0, readding nodes */
+	for (ssize_t curdepth = maxdepth; curdepth > -1; curdepth--)
+	{
+		LIF_LIST_FOREACH_SAFE(iter, iter_next, temp_list.head)
+		{
+			struct lif_dict_entry *entry = iter->data;
+			struct lif_interface *iface = entry->data;
+
+			if ((ssize_t) iface->rdepends_count != curdepth)
+				continue;
+
+			lif_node_delete(iter, &temp_list);
+			memset(iter, 0, sizeof *iter);
+
+			lif_node_insert(iter, entry, &collection->list);
+		}
+	}
+
+	return maxdepth;
+}

libifupdown/lifecycle.h

@@ -22,6 +22,7 @@
 extern bool lif_lifecycle_query_dependents(const struct lif_execute_opts *opts, struct lif_interface *iface, const char *lifname);
 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 *collection, struct lif_dict *state, const char *lifname, bool up);
+extern ssize_t lif_lifecycle_count_rdepends(const struct lif_execute_opts *opts, struct lif_dict *collection);
 
 #endif
 

tests/fixtures/teardown-dep-ordering.ifstate

@@ -0,0 +1,3 @@
+dummy=dummy 2
+bat=bat 2
+br=br 1

tests/fixtures/teardown-dep-ordering.interfaces

@@ -0,0 +1,13 @@
+auto dummy
+iface dummy
+	link-type dummy
+
+auto bat
+iface bat
+	link-type dummy
+	requires dummy
+
+auto br
+iface br
+	link-type dummy
+	requires bat

tests/ifdown_test

@@ -22,6 +22,7 @@ tests_init \
 	deferred_teardown_1 \
 	deferred_teardown_2 \
 	deferred_teardown_3 \
+	teardown_dep_ordering \
 	regress_opt_f
 
 noargs_body() {
@@ -172,6 +173,14 @@ deferred_teardown_3_body() {
 			-i $FIXTURES/deferred-teardown-2.interfaces tun0 tun1 tun2 tun3
 }
 
+teardown_dep_ordering_body() {
+	atf_check -s exit:0 -o ignore \
+		-e match:"skipping auto interface bat" \
+		-e match:"skipping auto interface dummy" \
+		ifdown -n -i $FIXTURES/teardown-dep-ordering.interfaces \
+			-S $FIXTURES/teardown-dep-ordering.ifstate -E $EXECUTORS -a
+}
+
 regress_opt_f_body() {
 	atf_check -s exit:0 -o ignore -e ignore \
 		ifdown -n -S $FIXTURES/vlan.ifstate -E $EXECUTORS -i $FIXTURES/vlan.interfaces -f eth0.8

tests/ifup_test

@@ -18,7 +18,8 @@ tests_init \
 	learned_dependency \
 	learned_dependency_2 \
 	learned_executor \
-	implicit_vlan
+	implicit_vlan \
+	teardown_dep_ordering
 
 noargs_body() {
 	atf_check -s exit:1 -e ignore ifup -S/dev/null
@@ -131,3 +132,10 @@ implicit_vlan_body() {
 		-e match:"attempting to run link executor" \
 		ifup -n -S/dev/null -E $EXECUTORS -i $FIXTURES/vlan.interfaces eth0.8
 }
+
+teardown_dep_ordering_body() {
+	atf_check -s exit:0 -o ignore \
+		-e match:"skipping auto interface bat" \
+		-e match:"skipping auto interface dummy" \
+		ifup -n -i $FIXTURES/teardown-dep-ordering.interfaces -E $EXECUTORS -a
+}