legacy: Const-ify hci packet transfer interface

Bug: 187830698
Tag: #refactor
Test: gd/cert/run

Change-Id: Ibed86eda3902de932e4d4a2e68d88b964a07fdc7

system/hci/include/hci_layer.h

@@ -62,11 +62,11 @@ typedef struct hci_t {
       base::Callback<void(const base::Location&, BT_HDR*)> send_data_cb);
 
   // Send a command through the HCI layer
-  void (*transmit_command)(BT_HDR* command,
+  void (*transmit_command)(const BT_HDR* command,
                            command_complete_cb complete_callback,
                            command_status_cb status_cb, void* context);
 
-  future_t* (*transmit_command_futured)(BT_HDR* command);
+  future_t* (*transmit_command_futured)(const BT_HDR* command);
 
   // Send some data downward through the HCI layer
   void (*transmit_downward)(uint16_t type, void* data);

system/main/shim/hci_layer.cc

@@ -361,11 +361,11 @@ void OnTransmitPacketStatus(command_status_cb status_callback, void* context,
   status_callback(status, static_cast<BT_HDR*>(command->Release()), context);
 }
 
-static void transmit_command(BT_HDR* command,
+static void transmit_command(const BT_HDR* command,
                              command_complete_cb complete_callback,
                              command_status_cb status_callback, void* context) {
   CHECK(command != nullptr);
-  uint8_t* data = command->data + command->offset;
+  const uint8_t* data = command->data + command->offset;
   size_t len = command->len;
   CHECK(len >= (kCommandOpcodeSize + kCommandLengthSize));
 
@@ -395,7 +395,7 @@ static void transmit_command(BT_HDR* command,
         std::move(packet),
         bluetooth::shim::GetGdShimHandler()->BindOnce(
             OnTransmitPacketCommandComplete, complete_callback, context));
-    osi_free(command);
+    osi_free(const_cast<void*>(static_cast<const void*>(command)));
   }
 }
 
@@ -677,7 +677,7 @@ void OnRustTransmitPacketStatus(command_status_cb status_callback,
   status_callback(status, static_cast<BT_HDR*>(command->Release()), context);
 }
 
-static void transmit_command(BT_HDR* command,
+static void transmit_command(const BT_HDR* command,
                              command_complete_cb complete_callback,
                              command_status_cb status_callback, void* context) {
   CHECK(command != nullptr);
@@ -705,7 +705,7 @@ static void transmit_command(BT_HDR* command,
         ::rust::Slice(data, len),
         std::make_unique<u8SliceOnceCallback>(BindOnce(
             OnRustTransmitPacketCommandComplete, complete_callback, context)));
-    osi_free(command);
+    osi_free(const_cast<void*>(static_cast<const void*>(command)));
   }
 }
 
@@ -775,7 +775,7 @@ static void set_data_cb(
   send_data_upwards = std::move(send_data_cb);
 }
 
-static void transmit_command(BT_HDR* command,
+static void transmit_command(const BT_HDR* command,
                              command_complete_cb complete_callback,
                              command_status_cb status_callback, void* context) {
   if (bluetooth::common::init_flags::gd_rust_is_enabled()) {
@@ -797,7 +797,7 @@ static void command_status_callback(uint8_t status, BT_HDR* command,
       "transmit_command_futured should only send command complete opcode");
 }
 
-static future_t* transmit_command_futured(BT_HDR* command) {
+static future_t* transmit_command_futured(const BT_HDR* command) {
   future_t* future = future_new();
   transmit_command(command, command_complete_callback, command_status_callback,
                    future);