ble_mesh: Model message macros

Creates macros for determining model message lengths based on opcode,
payload length and MIC size. Also adds macro wrapping
NET_BUF_SIMPLE_DEFINE to serve the most common use case.

components/bt/esp_ble_mesh/mesh_core/access.c

@@ -761,21 +761,21 @@ void bt_mesh_model_msg_init(struct net_buf_simple *msg, u32_t opcode)
 {
     net_buf_simple_init(msg, 0);
 
-    if (opcode < 0x100) {
+    switch (BLE_MESH_MODEL_OP_LEN(opcode)) {
-        /* 1-byte OpCode */
+    case 1:
         net_buf_simple_add_u8(msg, opcode);
-        return;
+        break;
-    }
+    case 2:
-
-    if (opcode < 0x10000) {
-        /* 2-byte OpCode */
         net_buf_simple_add_be16(msg, opcode);
-        return;
+        break;
+    case 3:
+        net_buf_simple_add_u8(msg, ((opcode >> 16) & 0xff));
+        net_buf_simple_add_le16(msg, opcode & 0xffff);
+        break;
+    default:
+        BT_WARN("Unknown opcode format");
+        break;
     }
-
-    /* 3-byte OpCode */
-    net_buf_simple_add_u8(msg, ((opcode >> 16) & 0xff));
-    net_buf_simple_add_le16(msg, opcode & 0xffff);
 }
 
 static bool ready_to_send(u8_t role, u16_t dst)

components/bt/esp_ble_mesh/mesh_core/cfg_cli.c

@@ -29,6 +29,9 @@
 
 #define CID_NVAL 0xffff
 
+/* 2 byte dummy opcode for getting compile time buffer sizes. */
+#define DUMMY_2_BYTE_OP     BLE_MESH_MODEL_OP_2(0xff, 0xff)
+
 s32_t config_msg_timeout;
 
 static bt_mesh_config_client_t *cli;
@@ -685,7 +688,7 @@ const struct bt_mesh_model_op bt_mesh_cfg_cli_op[] = {
 
 int bt_mesh_cfg_comp_data_get(struct bt_mesh_msg_ctx *ctx, u8_t page)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_DEV_COMP_DATA_GET, 1);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -707,7 +710,7 @@ int bt_mesh_cfg_comp_data_get(struct bt_mesh_msg_ctx *ctx, u8_t page)
 
 static int get_state_u8(struct bt_mesh_msg_ctx *ctx, u32_t op)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 0);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -723,7 +726,7 @@ static int get_state_u8(struct bt_mesh_msg_ctx *ctx, u32_t op)
 
 static int set_state_u8(struct bt_mesh_msg_ctx *ctx, u32_t op, u8_t new_val)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 1);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -804,7 +807,7 @@ int bt_mesh_cfg_gatt_proxy_set(struct bt_mesh_msg_ctx *ctx, u8_t val)
 
 int bt_mesh_cfg_relay_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -826,7 +829,7 @@ int bt_mesh_cfg_relay_get(struct bt_mesh_msg_ctx *ctx)
 int bt_mesh_cfg_relay_set(struct bt_mesh_msg_ctx *ctx, u8_t new_relay,
                           u8_t new_transmit)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_SET, 2);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -850,7 +853,7 @@ int bt_mesh_cfg_relay_set(struct bt_mesh_msg_ctx *ctx, u8_t new_relay,
 int bt_mesh_cfg_net_key_add(struct bt_mesh_msg_ctx *ctx, u16_t key_net_idx,
                             const u8_t net_key[16])
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 18 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_ADD, 18);
     int err;
 
     if (!ctx || !ctx->addr || !net_key) {
@@ -874,7 +877,7 @@ int bt_mesh_cfg_net_key_add(struct bt_mesh_msg_ctx *ctx, u16_t key_net_idx,
 int bt_mesh_cfg_app_key_add(struct bt_mesh_msg_ctx *ctx, u16_t key_net_idx,
                             u16_t key_app_idx, const u8_t app_key[16])
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 1 + 19 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_ADD, 19);
     int err;
 
     if (!ctx || !ctx->addr || !app_key) {
@@ -898,7 +901,7 @@ int bt_mesh_cfg_app_key_add(struct bt_mesh_msg_ctx *ctx, u16_t key_net_idx,
 int bt_mesh_cfg_mod_app_bind(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                              u16_t mod_app_idx, u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 8 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_BIND, 8);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -926,7 +929,7 @@ int bt_mesh_cfg_mod_app_bind(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 static int mod_sub(u32_t op, struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                    u16_t sub_addr, u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 8 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 8);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -976,7 +979,7 @@ int bt_mesh_cfg_mod_sub_overwrite(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 static int mod_sub_va(u32_t op, struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                       const u8_t label[16], u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 22 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 22);
     int err;
 
     BT_DBG("net_idx 0x%04x addr 0x%04x elem_addr 0x%04x label %s",
@@ -1030,7 +1033,7 @@ int bt_mesh_cfg_mod_sub_va_overwrite(struct bt_mesh_msg_ctx *ctx, u16_t elem_add
 int bt_mesh_cfg_mod_pub_get(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                             u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 6 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_PUB_GET, 6);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1058,7 +1061,7 @@ int bt_mesh_cfg_mod_pub_set(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                             u16_t mod_id, u16_t cid,
                             struct bt_mesh_cfg_mod_pub *pub)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 13 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_PUB_SET, 13);
     int err;
 
     if (!ctx || !ctx->addr || !pub) {
@@ -1090,7 +1093,7 @@ int bt_mesh_cfg_mod_pub_set(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 int bt_mesh_cfg_hb_sub_set(struct bt_mesh_msg_ctx *ctx,
                            struct bt_mesh_cfg_hb_sub *sub)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 5 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_SUB_SET, 5);
     int err;
 
     if (!ctx || !ctx->addr || !sub) {
@@ -1114,7 +1117,7 @@ int bt_mesh_cfg_hb_sub_set(struct bt_mesh_msg_ctx *ctx,
 
 int bt_mesh_cfg_hb_sub_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_SUB_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1136,7 +1139,7 @@ int bt_mesh_cfg_hb_sub_get(struct bt_mesh_msg_ctx *ctx)
 int bt_mesh_cfg_hb_pub_set(struct bt_mesh_msg_ctx *ctx,
                            const struct bt_mesh_cfg_hb_pub *pub)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_PUB_SET, 9);
     int err;
 
     if (!ctx || !ctx->addr || !pub) {
@@ -1163,7 +1166,7 @@ int bt_mesh_cfg_hb_pub_set(struct bt_mesh_msg_ctx *ctx,
 
 int bt_mesh_cfg_hb_pub_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_PUB_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1184,7 +1187,7 @@ int bt_mesh_cfg_hb_pub_get(struct bt_mesh_msg_ctx *ctx)
 
 int bt_mesh_cfg_node_reset(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NODE_RESET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1207,7 +1210,7 @@ int bt_mesh_cfg_mod_pub_va_set(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                                u16_t mod_id, u16_t cid, const u8_t label[16],
                                struct bt_mesh_cfg_mod_pub *pub)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 27 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_PUB_VA_SET, 27);
     int err;
 
     if (!ctx || !ctx->addr || !label || !pub) {
@@ -1239,7 +1242,7 @@ int bt_mesh_cfg_mod_pub_va_set(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 int bt_mesh_cfg_mod_sub_del_all(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                                 u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 6 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_SUB_DEL_ALL, 6);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1266,7 +1269,7 @@ int bt_mesh_cfg_mod_sub_del_all(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 static int mod_sub_get(u32_t op, struct bt_mesh_msg_ctx *ctx,
                        u16_t elem_addr, u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 6 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 6);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -1305,7 +1308,7 @@ int bt_mesh_cfg_mod_sub_get_vnd(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 int bt_mesh_cfg_net_key_update(struct bt_mesh_msg_ctx *ctx, u16_t net_idx,
                                const u8_t net_key[16])
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 18 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_UPDATE, 18);
     int err;
 
     if (!ctx || !ctx->addr || !net_key) {
@@ -1328,7 +1331,7 @@ int bt_mesh_cfg_net_key_update(struct bt_mesh_msg_ctx *ctx, u16_t net_idx,
 
 int bt_mesh_cfg_net_key_delete(struct bt_mesh_msg_ctx *ctx, u16_t net_idx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_DEL, 2);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1350,7 +1353,7 @@ int bt_mesh_cfg_net_key_delete(struct bt_mesh_msg_ctx *ctx, u16_t net_idx)
 
 int bt_mesh_cfg_net_key_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1372,7 +1375,7 @@ int bt_mesh_cfg_net_key_get(struct bt_mesh_msg_ctx *ctx)
 int bt_mesh_cfg_app_key_update(struct bt_mesh_msg_ctx *ctx, u16_t net_idx,
                                u16_t app_idx, const u8_t app_key[16])
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 1 + 19 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_UPDATE, 19);
     int err;
 
     if (!ctx || !ctx->addr || !app_key) {
@@ -1395,7 +1398,7 @@ int bt_mesh_cfg_app_key_update(struct bt_mesh_msg_ctx *ctx, u16_t net_idx,
 
 int bt_mesh_cfg_app_key_delete(struct bt_mesh_msg_ctx *ctx, u16_t net_idx, u16_t app_idx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_DEL, 3);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1417,7 +1420,7 @@ int bt_mesh_cfg_app_key_delete(struct bt_mesh_msg_ctx *ctx, u16_t net_idx, u16_t
 
 int bt_mesh_cfg_app_key_get(struct bt_mesh_msg_ctx *ctx, u16_t net_idx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_GET, 2);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1440,7 +1443,7 @@ int bt_mesh_cfg_app_key_get(struct bt_mesh_msg_ctx *ctx, u16_t net_idx)
 static int node_identity_op(u32_t op, struct bt_mesh_msg_ctx *ctx,
                             u16_t net_idx, u8_t identity)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 3);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -1477,7 +1480,7 @@ int bt_mesh_cfg_node_identity_set(struct bt_mesh_msg_ctx *ctx, u16_t net_idx, u8
 int bt_mesh_cfg_mod_app_unbind(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
                                u16_t app_idx, u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 8 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_UNBIND, 8);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -1505,7 +1508,7 @@ int bt_mesh_cfg_mod_app_unbind(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 static int mod_app_get(u32_t op, struct bt_mesh_msg_ctx *ctx,
                        u16_t elem_addr, u16_t mod_id, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 6 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 6);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -1544,7 +1547,7 @@ int bt_mesh_cfg_mod_app_get_vnd(struct bt_mesh_msg_ctx *ctx, u16_t elem_addr,
 static int kr_phase_op(u32_t op, struct bt_mesh_msg_ctx *ctx,
                        u16_t net_idx, u8_t transition)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, DUMMY_2_BYTE_OP, 3);
     int err;
 
     bt_mesh_model_msg_init(&msg, op);
@@ -1580,7 +1583,7 @@ int bt_mesh_cfg_kr_phase_set(struct bt_mesh_msg_ctx *ctx, u16_t net_idx, u8_t tr
 
 int bt_mesh_cfg_lpn_timeout_get(struct bt_mesh_msg_ctx *ctx, u16_t lpn_addr)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_LPN_TIMEOUT_GET, 2);
     int err;
 
     if (!ctx || !ctx->addr) {

components/bt/esp_ble_mesh/mesh_core/cfg_srv.c

@@ -451,7 +451,7 @@ static void app_key_add(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_STATUS, 4);
     u16_t key_net_idx, key_app_idx;
     u8_t status;
 
@@ -486,7 +486,7 @@ static void app_key_update(struct bt_mesh_model *model,
                            struct bt_mesh_msg_ctx *ctx,
                            struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_STATUS, 4);
     u16_t key_net_idx, key_app_idx;
     u8_t status;
 
@@ -549,7 +549,7 @@ static void app_key_del(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_STATUS, 4);
     u16_t key_net_idx, key_app_idx;
     struct bt_mesh_app_key *key;
     u8_t status;
@@ -607,8 +607,8 @@ static void app_key_get(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4 +
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_APP_KEY_LIST,
-                          IDX_LEN(CONFIG_BLE_MESH_APP_KEY_COUNT));
+                              3 + IDX_LEN(CONFIG_BLE_MESH_APP_KEY_COUNT));
     u16_t get_idx, i, prev;
     u8_t status;
 
@@ -666,8 +666,7 @@ static void beacon_get(struct bt_mesh_model *model,
                        struct bt_mesh_msg_ctx *ctx,
                        struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_BEACON_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
            ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -685,8 +684,7 @@ static void beacon_set(struct bt_mesh_model *model,
                        struct bt_mesh_msg_ctx *ctx,
                        struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_BEACON_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
@@ -728,8 +726,7 @@ static void default_ttl_get(struct bt_mesh_model *model,
                             struct bt_mesh_msg_ctx *ctx,
                             struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_DEFAULT_TTL_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
            ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -747,8 +744,7 @@ static void default_ttl_set(struct bt_mesh_model *model,
                             struct bt_mesh_msg_ctx *ctx,
                             struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_DEFAULT_TTL_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
@@ -781,8 +777,7 @@ static void default_ttl_set(struct bt_mesh_model *model,
 static void send_gatt_proxy_status(struct bt_mesh_model *model,
                                    struct bt_mesh_msg_ctx *ctx)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_GATT_PROXY_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
 
     bt_mesh_model_msg_init(&msg, OP_GATT_PROXY_STATUS);
     net_buf_simple_add_u8(&msg, bt_mesh_gatt_proxy_get());
@@ -878,8 +873,7 @@ static void net_transmit_get(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx,
                              struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_TRANSMIT_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
            ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -897,8 +891,7 @@ static void net_transmit_set(struct bt_mesh_model *model,
                              struct bt_mesh_msg_ctx *ctx,
                              struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_TRANSMIT_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
@@ -931,8 +924,7 @@ static void relay_get(struct bt_mesh_model *model,
                       struct bt_mesh_msg_ctx *ctx,
                       struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_STATUS, 2);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
            ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -951,8 +943,7 @@ static void relay_set(struct bt_mesh_model *model,
                       struct bt_mesh_msg_ctx *ctx,
                       struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_RELAY_STATUS, 2);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
@@ -1005,8 +996,7 @@ static void send_mod_pub_status(struct bt_mesh_model *cfg_mod,
                                 bool vnd, struct bt_mesh_model *mod,
                                 u8_t status, u8_t *mod_id)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_PUB_STATUS, 14);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 14 + 4);
 
     bt_mesh_model_msg_init(&msg, OP_MOD_PUB_STATUS);
 
@@ -1386,8 +1376,7 @@ static void send_mod_sub_status(struct bt_mesh_model *model,
                                 u16_t elem_addr, u16_t sub_addr, u8_t *mod_id,
                                 bool vnd)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_SUB_STATUS, 9);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + 4);
 
     BT_DBG("status 0x%02x elem_addr 0x%04x sub_addr 0x%04x", status,
            elem_addr, sub_addr);
@@ -1696,8 +1685,8 @@ static void mod_sub_get(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 5 + 4 +
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_SUB_LIST,
-                          CONFIG_BLE_MESH_MODEL_GROUP_COUNT * 2);
+                              5 + CONFIG_BLE_MESH_MODEL_GROUP_COUNT * 2);
     struct bt_mesh_model *mod;
     struct bt_mesh_elem *elem;
     u16_t addr, id;
@@ -1752,8 +1741,8 @@ static void mod_sub_get_vnd(struct bt_mesh_model *model,
                             struct bt_mesh_msg_ctx *ctx,
                             struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 7 + 4 +
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_SUB_LIST_VND,
-                          CONFIG_BLE_MESH_MODEL_GROUP_COUNT * 2);
+                              7 + CONFIG_BLE_MESH_MODEL_GROUP_COUNT * 2);
     struct bt_mesh_model *mod;
     struct bt_mesh_elem *elem;
     u16_t company, addr, id;
@@ -2145,8 +2134,7 @@ static void send_net_key_status(struct bt_mesh_model *model,
                                 struct bt_mesh_msg_ctx *ctx,
                                 u16_t idx, u8_t status)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_STATUS, 3);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4);
 
     bt_mesh_model_msg_init(&msg, OP_NET_KEY_STATUS);
 
@@ -2379,8 +2367,8 @@ static void net_key_get(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg,
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NET_KEY_LIST,
-                          2 + 4 + IDX_LEN(CONFIG_BLE_MESH_SUBNET_COUNT));
+                              IDX_LEN(CONFIG_BLE_MESH_SUBNET_COUNT));
     u16_t prev, i;
 
     bt_mesh_model_msg_init(&msg, OP_NET_KEY_LIST);
@@ -2415,8 +2403,7 @@ static void node_identity_get(struct bt_mesh_model *model,
                               struct bt_mesh_msg_ctx *ctx,
                               struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NODE_IDENTITY_STATUS, 4);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
     struct bt_mesh_subnet *sub;
     u8_t node_id;
     u16_t idx;
@@ -2454,8 +2441,7 @@ static void node_identity_set(struct bt_mesh_model *model,
                               struct bt_mesh_msg_ctx *ctx,
                               struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NODE_IDENTITY_STATUS, 4);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
     struct bt_mesh_subnet *sub;
     u8_t node_id;
     u16_t idx;
@@ -2531,7 +2517,7 @@ static void mod_app_bind(struct bt_mesh_model *model,
                          struct bt_mesh_msg_ctx *ctx,
                          struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_STATUS, 9);
     u16_t elem_addr, key_app_idx;
     struct bt_mesh_model *mod;
     struct bt_mesh_elem *elem;
@@ -2594,7 +2580,7 @@ static void mod_app_unbind(struct bt_mesh_model *model,
                            struct bt_mesh_msg_ctx *ctx,
                            struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_MOD_APP_STATUS, 9);
     u16_t elem_addr, key_app_idx;
     struct bt_mesh_model *mod;
     struct bt_mesh_elem *elem;
@@ -2652,7 +2638,11 @@ static void mod_app_get(struct bt_mesh_model *model,
                         struct bt_mesh_msg_ctx *ctx,
                         struct net_buf_simple *buf)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + KEY_LIST_LEN + 4);
+    NET_BUF_SIMPLE_DEFINE(msg,
+                          MAX(BLE_MESH_MODEL_BUF_LEN(OP_VND_MOD_APP_LIST,
+                                                     9 + KEY_LIST_LEN),
+                              BLE_MESH_MODEL_BUF_LEN(OP_SIG_MOD_APP_LIST,
+                                                     9 + KEY_LIST_LEN)));
     struct bt_mesh_model *mod;
     struct bt_mesh_elem *elem;
     u8_t *mod_id, status;
@@ -2720,8 +2710,7 @@ static void node_reset(struct bt_mesh_model *model,
                        struct bt_mesh_msg_ctx *ctx,
                        struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_NODE_RESET_STATUS, 0);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
 
     BT_DBG("net_idx 0x%04x app_idx 0x%04x src 0x%04x len %u: %s",
            ctx->net_idx, ctx->app_idx, ctx->addr, buf->len,
@@ -2745,8 +2734,7 @@ static void node_reset(struct bt_mesh_model *model,
 static void send_friend_status(struct bt_mesh_model *model,
                                struct bt_mesh_msg_ctx *ctx)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_FRIEND_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     bt_mesh_model_msg_init(&msg, OP_FRIEND_STATUS);
@@ -2818,8 +2806,7 @@ static void lpn_timeout_get(struct bt_mesh_model *model,
                             struct bt_mesh_msg_ctx *ctx,
                             struct net_buf_simple *buf)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_LPN_TIMEOUT_STATUS, 5);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 5 + 4);
     struct bt_mesh_friend *frnd;
     u16_t lpn_addr;
     s32_t timeout;
@@ -2864,8 +2851,7 @@ static void send_krp_status(struct bt_mesh_model *model,
                             struct bt_mesh_msg_ctx *ctx,
                             u16_t idx, u8_t phase, u8_t status)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_KRP_STATUS, 4);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 4 + 4);
 
     bt_mesh_model_msg_init(&msg, OP_KRP_STATUS);
 
@@ -3008,8 +2994,7 @@ static void hb_pub_send_status(struct bt_mesh_model *model,
                                struct bt_mesh_msg_ctx *ctx, u8_t status,
                                struct hb_pub_param *orig_msg)
 {
-    /* Needed size: opcode (1 byte) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_PUB_STATUS, 10);
-    NET_BUF_SIMPLE_DEFINE(msg, 1 + 10 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
 
     BT_DBG("src 0x%04x status 0x%02x", ctx->addr, status);
@@ -3147,8 +3132,7 @@ failed:
 static void hb_sub_send_status(struct bt_mesh_model *model,
                                struct bt_mesh_msg_ctx *ctx, u8_t status)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEARTBEAT_SUB_STATUS, 9);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 9 + 4);
     struct bt_mesh_cfg_srv *cfg = model->user_data;
     u16_t period;
     s64_t uptime;

components/bt/esp_ble_mesh/mesh_core/health_cli.c

@@ -235,7 +235,7 @@ const struct bt_mesh_model_op bt_mesh_health_cli_op[] = {
 
 int bt_mesh_health_attention_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_ATTENTION_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -257,7 +257,7 @@ int bt_mesh_health_attention_get(struct bt_mesh_msg_ctx *ctx)
 int bt_mesh_health_attention_set(struct bt_mesh_msg_ctx *ctx,
                                  u8_t attention, bool need_ack)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_ATTENTION_SET, 1);
     u32_t opcode;
     int err;
 
@@ -285,7 +285,7 @@ int bt_mesh_health_attention_set(struct bt_mesh_msg_ctx *ctx,
 
 int bt_mesh_health_period_get(struct bt_mesh_msg_ctx *ctx)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 0 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_PERIOD_GET, 0);
     int err;
 
     if (!ctx || !ctx->addr) {
@@ -307,7 +307,7 @@ int bt_mesh_health_period_get(struct bt_mesh_msg_ctx *ctx)
 int bt_mesh_health_period_set(struct bt_mesh_msg_ctx *ctx,
                               u8_t divisor, bool need_ack)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_PERIOD_SET, 1);
     u32_t opcode;
     int err;
 
@@ -336,7 +336,7 @@ int bt_mesh_health_period_set(struct bt_mesh_msg_ctx *ctx,
 int bt_mesh_health_fault_test(struct bt_mesh_msg_ctx *ctx,
                               u16_t cid, u8_t test_id, bool need_ack)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 3 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_FAULT_TEST, 3);
     u32_t opcode;
     int err;
 
@@ -366,7 +366,7 @@ int bt_mesh_health_fault_test(struct bt_mesh_msg_ctx *ctx,
 int bt_mesh_health_fault_clear(struct bt_mesh_msg_ctx *ctx,
                                u16_t cid, bool need_ack)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_FAULT_CLEAR, 2);
     u32_t opcode;
     int err;
 
@@ -394,7 +394,7 @@ int bt_mesh_health_fault_clear(struct bt_mesh_msg_ctx *ctx,
 
 int bt_mesh_health_fault_get(struct bt_mesh_msg_ctx *ctx, u16_t cid)
 {
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 2 + 4);
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_FAULT_GET, 2);
     int err;
 
     if (!ctx || !ctx->addr) {

components/bt/esp_ble_mesh/mesh_core/health_srv.c

@@ -227,8 +227,7 @@ static void health_fault_test(struct bt_mesh_model *model,
 static void send_attention_status(struct bt_mesh_model *model,
                                   struct bt_mesh_msg_ctx *ctx)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_ATTENTION_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
     struct bt_mesh_health_srv *srv = model->user_data;
     u8_t time;
 
@@ -286,8 +285,7 @@ static void attention_set(struct bt_mesh_model *model,
 static void send_health_period_status(struct bt_mesh_model *model,
                                       struct bt_mesh_msg_ctx *ctx)
 {
-    /* Needed size: opcode (2 bytes) + msg + MIC */
+    BLE_MESH_MODEL_BUF_DEFINE(msg, OP_HEALTH_PERIOD_STATUS, 1);
-    NET_BUF_SIMPLE_DEFINE(msg, 2 + 1 + 4);
 
     bt_mesh_model_msg_init(&msg, OP_HEALTH_PERIOD_STATUS);
     net_buf_simple_add_u8(&msg, model->pub->period_div);

components/bt/esp_ble_mesh/mesh_core/include/mesh_access.h

@@ -188,6 +188,56 @@ struct bt_mesh_model_op {
 /** Helper to define an empty model array */
 #define BLE_MESH_MODEL_NONE ((struct bt_mesh_model []){})
 
+/** Length of a short Mesh MIC. */
+#define BLE_MESH_MIC_SHORT 4
+/** Length of a long Mesh MIC. */
+#define BLE_MESH_MIC_LONG 8
+
+/** @def BLE_MESH_MODEL_OP_LEN
+ *
+ * @brief Helper to determine the length of an opcode.
+ *
+ * @param _op Opcode.
+ */
+#define BLE_MESH_MODEL_OP_LEN(_op) ((_op) <= 0xff ? 1 : (_op) <= 0xffff ? 2 : 3)
+
+/** @def BLE_MESH_MODEL_BUF_LEN
+ *
+ * @brief Helper for model message buffer length.
+ *
+ * Returns the length of a Mesh model message buffer, including the opcode
+ * length and a short MIC.
+ *
+ * @param _op Opcode of the message.
+ * @param _payload_len Length of the model payload.
+ */
+#define BLE_MESH_MODEL_BUF_LEN(_op, _payload_len)                \
+        (BLE_MESH_MODEL_OP_LEN(_op) + (_payload_len) + BLE_MESH_MIC_SHORT)
+
+/** @def BLE_MESH_MODEL_BUF_LEN_LONG_MIC
+ *
+ * @brief Helper for model message buffer length.
+ *
+ * Returns the length of a Mesh model message buffer, including the opcode
+ * length and a long MIC.
+ *
+ * @param _op Opcode of the message.
+ * @param _payload_len Length of the model payload.
+ */
+#define BLE_MESH_MODEL_BUF_LEN_LONG_MIC(_op, _payload_len)       \
+        (BLE_MESH_MODEL_OP_LEN(_op) + (_payload_len) + BLE_MESH_MIC_LONG)
+
+/** @def BLE_MESH_MODEL_BUF_DEFINE
+ *
+ * @brief Define a Mesh model message buffer using @ref NET_BUF_SIMPLE_DEFINE.
+ *
+ * @param _buf Buffer name.
+ * @param _op Opcode of the message.
+ * @param _payload_len Length of the model message payload.
+ */
+#define BLE_MESH_MODEL_BUF_DEFINE(_buf, _op, _payload_len)       \
+        NET_BUF_SIMPLE_DEFINE(_buf, BLE_MESH_MODEL_BUF_LEN(_op, (_payload_len)))
+
 #define BLE_MESH_MODEL(_id, _op, _pub, _user_data)                  \
 {                                                                   \
     .id = (_id),                                                    \