[LEDE-DEV] [PATCH v2 1/5 netifd] proto-shell: Support teardown on layer 3 link loss

[Hans Dedecker]

Commit c6858766 added interface teardown support on layer 3 device link loss
mainly for shell protocols who have no proto task like xl2tp. However for
shell protocols having a proto task it is not always the correct action to
teardown the interface; as an example the PPP daemon can be put into
persist state trying to re-establish the link via a hold-off mechanism
if layer 3 link loss is detected.
Therefore shell handlers can enable via TEARDOWN_ON_L3_LINK_DOWN a proto
flag which will teardown the interface when layer 3 link loss is detected

Signed-off-by: Hans Dedecker <dedeckeh at gmail.com>
---

Changes in v2:
    -Define seperate proto flag to enable teardown on layer3 link loss

 interface.c             | 3 ++-
 proto-shell.c           | 4 ++++
 proto.h                 | 1 +
 scripts/netifd-proto.sh | 2 ++
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/interface.c b/interface.c
index b9833d3..0b9893c 100644
--- a/interface.c
+++ b/interface.c
@@ -414,7 +414,8 @@ interface_l3_dev_cb(struct device_user *dep, enum device_event ev)
 
 	switch (ev) {
 	case DEV_EVENT_LINK_DOWN:
-		interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, false);
+		if (iface->proto_handler->flags & PROTO_FLAG_TEARDOWN_ON_L3_LINK_DOWN)
+			interface_proto_event(iface->proto, PROTO_CMD_TEARDOWN, false);
 		break;
 	default:
 		break;
diff --git a/proto-shell.c b/proto-shell.c
index 25dec00..4391cdd 100644
--- a/proto-shell.c
+++ b/proto-shell.c
@@ -906,6 +906,10 @@ proto_shell_add_handler(const char *script, const char *name, json_object *obj)
 	if (tmp && json_object_get_boolean(tmp))
 		handler->proto.flags |= PROTO_FLAG_LASTERROR;
 
+	tmp = json_get_field(obj, "teardown-on-l3-link-down", json_type_boolean);
+	if (tmp && json_object_get_boolean(tmp))
+		handler->proto.flags |= PROTO_FLAG_TEARDOWN_ON_L3_LINK_DOWN;
+
 	config = json_get_field(obj, "config", json_type_array);
 	if (config)
 		handler->config_buf = netifd_handler_parse_config(&handler->config, config);
diff --git a/proto.h b/proto.h
index 87dec4e..8f50fdc 100644
--- a/proto.h
+++ b/proto.h
@@ -38,6 +38,7 @@ enum {
 	PROTO_FLAG_RENEW_AVAILABLE = (1 << 3),
 	PROTO_FLAG_FORCE_LINK_DEFAULT = (1 << 4),
 	PROTO_FLAG_LASTERROR = (1 << 5),
+	PROTO_FLAG_TEARDOWN_ON_L3_LINK_DOWN = (1 << 6),
 };
 
 struct interface_proto_state {
diff --git a/scripts/netifd-proto.sh b/scripts/netifd-proto.sh
index 447f0f6..64b3cab 100644
--- a/scripts/netifd-proto.sh
+++ b/scripts/netifd-proto.sh
@@ -365,6 +365,7 @@ init_proto() {
 				no_proto_task=0
 				available=0
 				renew_handler=0
+				teardown_on_l3_link_down=0
 
 				add_default_handler "proto_$1_init_config"
 
@@ -378,6 +379,7 @@ init_proto() {
 				json_add_boolean available "$available"
 				json_add_boolean renew-handler "$renew_handler"
 				json_add_boolean lasterror "$lasterror"
+				json_add_boolean teardown-on-l3-link-down "$teardown_on_l3_link_down"
 				json_dump
 			}
 		;;
-- 
1.9.1