[PATCH 3/3] mesh: allow to reattach with new composition data

[Jakub Witowski <jakub.witowski@silvair.com>]

---
 mesh/node.c | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/mesh/node.c b/mesh/node.c
index 6fe70742d..f9a2d5722 100644
--- a/mesh/node.c
+++ b/mesh/node.c
@@ -47,6 +47,12 @@
 
 #define MIN_COMP_SIZE 14
 
+/* Composition data header size contains the length of belows:
+ * CID, PID, VID, CRPL and Feature bits
+ */
+#define COMP_HDR_SIZE 10
+#define COMP_FEATURE_BITS_SIZE 2
+
 #define MESH_NODE_PATH_PREFIX "/node"
 
 /* Default values for a new locally created node */
@@ -1394,15 +1400,39 @@ static bool check_req_node(struct managed_obj_request *req)
 		uint16_t attach_len = node_generate_comp(req->attach,
 					attach_comp, sizeof(attach_comp));
 
-		/* Ignore feature bits in Composition Compare */
-		node_comp[8] = 0;
-		attach_comp[8] = 0;
-
+		/* Ignore CID, VID, PID, CRPL and feature bits
+		 * in Composition Compare
+		 */
 		if (node_len != attach_len ||
-				memcmp(node_comp, attach_comp, node_len)) {
+			memcmp(node_comp + COMP_HDR_SIZE,
+						attach_comp + COMP_HDR_SIZE,
+						node_len - COMP_HDR_SIZE)) {
 			l_debug("Failed to verify app's composition data");
 			return false;
 		}
+
+		/* Compare CID, VID, PID and CRPL */
+		if (!memcmp(node_comp, attach_comp,
+					COMP_HDR_SIZE - COMP_FEATURE_BITS_SIZE))
+			return true;
+
+		l_debug("Composition data update");
+
+		if (!mesh_config_write_comp(req->attach->cfg,
+				req->node->comp.cid, req->node->comp.pid,
+				req->node->comp.vid, req->node->comp.crpl)) {
+
+			l_debug("Failed to update composition data");
+			return false;
+		}
+
+		if (!mesh_config_save(req->attach->cfg, true, NULL, NULL)) {
+			l_debug("Failed to store composition data");
+			return false;
+		}
+
+		memcpy(&req->attach->comp, &req->node->comp,
+					sizeof(struct node_composition));
 	}
 
 	return true;
-- 
2.20.1