ble_mesh: GATT Proxy Spec 1.0.1 changes [Zephyr]

Backport of https://github.com/apache/mynewt-nimble/pull/724

Mesh spec 1.0.1 changes proxy disabling behavior to only affect the
relaying from proxy nodes. Previously, disabling proxy would shut down
all proxy and node activity.

Tweaks from the original commit:
- Removed redundant call to bt_mesh_adv_update() in gatt_proxy_set()
- Removed invalid ref to 4.2.11.1 in node_identity_set()

---

According to Mesh Profile Spec 1.0.1, Section 4.2.11:
"If the Proxy feature is disabled, a GATT client device can connect
over GATT to that node for configuration and control. Messages from
the GATT bearer are not relayed to the advertising bearer."

Moreover some notes have been removed from the spec compared to
version 1.0:

Mesh Profile Spec 1.0, Section 4.2.11:

"Upon transition from GATT Proxy state 0x01 to GATT Proxy state 0x00
the GATT Bearer Server shall disconnect all GATT Bearer Clients."

"The Configuration Client should turn off the Proxy state as the last
step in the configuration process."

Mesh Profile Spec 1.0, Section 4.2.11.1:

"When the GATT Proxy state is set to 0x00, the Node Identity state
for all subnets shall be set to 0x00 and shall not be changed."

components/bt/esp_ble_mesh/mesh_core/cfg_srv.c

@@ -822,30 +822,6 @@ static void gatt_proxy_set(struct bt_mesh_model *model,
         bt_mesh_store_cfg();
     }
 
-    if (cfg->gatt_proxy == BLE_MESH_GATT_PROXY_DISABLED) {
-        int i;
-
-        /* Section 4.2.11.1: "When the GATT Proxy state is set to
-         * 0x00, the Node Identity state for all subnets shall be set
-         * to 0x00 and shall not be changed."
-         */
-        for (i = 0; i < ARRAY_SIZE(bt_mesh.sub); i++) {
-            struct bt_mesh_subnet *sub = &bt_mesh.sub[i];
-
-            if (sub->net_idx != BLE_MESH_KEY_UNUSED) {
-                bt_mesh_proxy_identity_stop(sub);
-            }
-        }
-
-        /* Section 4.2.11: "Upon transition from GATT Proxy state 0x01
-         * to GATT Proxy state 0x00 the GATT Bearer Server shall
-         * disconnect all GATT Bearer Clients.
-         */
-        bt_mesh_proxy_gatt_disconnect();
-    }
-
-    bt_mesh_adv_update();
-
     if (cfg->hb_pub.feat & BLE_MESH_FEAT_PROXY) {
         bt_mesh_heartbeat_send();
     }
@@ -2493,12 +2469,8 @@ static void node_identity_set(struct bt_mesh_model *model,
     } else  {
         net_buf_simple_add_u8(&msg, STATUS_SUCCESS);
         net_buf_simple_add_le16(&msg, idx);
-        /* Section 4.2.11.1: "When the GATT Proxy state is set to
-         * 0x00, the Node Identity state for all subnets shall be set
-         * to 0x00 and shall not be changed."
-         */
-        if (IS_ENABLED(CONFIG_BLE_MESH_GATT_PROXY_SERVER) &&
-                bt_mesh_gatt_proxy_get() == BLE_MESH_GATT_PROXY_ENABLED) {
+
+        if (IS_ENABLED(CONFIG_BLE_MESH_GATT_PROXY_SERVER)) {
             if (node_id) {
                 bt_mesh_proxy_identity_start(sub);
             } else {

components/bt/esp_ble_mesh/mesh_core/net.c

@@ -1439,13 +1439,19 @@ void bt_mesh_net_recv(struct net_buf_simple *data, s8_t rssi,
     /* Save the state so the buffer can later be relayed */
     net_buf_simple_save(&buf, &state);
 
+    rx.local_match = (bt_mesh_fixed_group_match(rx.ctx.recv_dst) ||
+                      bt_mesh_elem_find(rx.ctx.recv_dst));
+
     if (IS_ENABLED(CONFIG_BLE_MESH_GATT_PROXY_SERVER) &&
             net_if == BLE_MESH_NET_IF_PROXY) {
         bt_mesh_proxy_addr_add(data, rx.ctx.addr);
-    }
 
-    rx.local_match = (bt_mesh_fixed_group_match(rx.ctx.recv_dst) ||
-                      bt_mesh_elem_find(rx.ctx.recv_dst));
+        if (bt_mesh_gatt_proxy_get() == BLE_MESH_GATT_PROXY_DISABLED &&
+            !rx.local_match) {
+            BT_INFO("Proxy is disabled; ignoring message");
+            return;
+        }
+    }
 
     /* The transport layer has indicated that it has rejected the message,
     * but would like to see it again if it is received in the future.

components/bt/esp_ble_mesh/mesh_core/proxy_server.c

@@ -1174,7 +1174,7 @@ static bool advertise_subnet(struct bt_mesh_subnet *sub)
     }
 
     return (sub->node_id == BLE_MESH_NODE_IDENTITY_RUNNING ||
-            bt_mesh_gatt_proxy_get() == BLE_MESH_GATT_PROXY_ENABLED);
+            bt_mesh_gatt_proxy_get() != BLE_MESH_GATT_PROXY_NOT_SUPPORTED);
 }
 
 static struct bt_mesh_subnet *next_sub(void)
@@ -1252,11 +1252,7 @@ static s32_t gatt_proxy_advertise(struct bt_mesh_subnet *sub)
     }
 
     if (sub->node_id == BLE_MESH_NODE_IDENTITY_STOPPED) {
-        if (bt_mesh_gatt_proxy_get() == BLE_MESH_GATT_PROXY_ENABLED) {
-            net_id_adv(sub);
-        } else {
-            return gatt_proxy_advertise(next_sub());
-        }
+        net_id_adv(sub);
     }
 
     subnet_count = sub_count();