From a39b9abfe1e7e1bea9c409a1680cb6f18a6ec354 Mon Sep 17 00:00:00 2001
From: penn5 <penn5@users.noreply.github.com>
Date: Mon, 4 Mar 2019 22:21:07 +0000
Subject: [PATCH 2/3] Add props to control supported features and states (#1)

* Add bitmask for supported fields
Use persist.sys.bt.unsupport.states, defaults to 0, left-aligned.
Huawei suggest to use 000000000000000000000011111

* Add bitmask to LOCAL_SUPPORTED_FEATURES
For Huawei, suggest to use 00000001

Documentation:
- persist.sys.bt.unsupport.features matches the values:
HCI_3_SLOT_PACKETS..HCI_LMP_EXTENDED_SUPPORTED (max 8bits * 8 bytes =
64 bits)
- persist.sys.bt.unsupport.states matches the values:
BTM_BLE_STATE_INVALID..BTM_BLE_STATE_SCAN_ADV (max = 0x3ff, 11 bits)
- persist.sys.bt.unsupport.stdfeatures ( max: 16 bits)
HCI_LE_ENCRYPTION..HCI_LE_PERIODIC_ADVERTISING
---
 hci/src/hci_packet_parser.cc | 77 ++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/hci/src/hci_packet_parser.cc b/hci/src/hci_packet_parser.cc
index b1efd444d..88dc4c6cd 100644
--- a/hci/src/hci_packet_parser.cc
+++ b/hci/src/hci_packet_parser.cc
@@ -27,6 +27,8 @@
 #include "hcimsgs.h"
 #include "osi/include/log.h"
 
+#include <cutils/properties.h>
+
 static const command_opcode_t NO_OPCODE_CHECKING = 0;
 
 static const allocator_t* buffer_allocator;
@@ -108,6 +110,31 @@ static void parse_read_local_supported_commands_response(
   buffer_allocator->free(response);
 }
 
+static void setup_bitmask(uint8_t *v, const char* property) {
+  char str[PROPERTY_VALUE_MAX];
+  int len = property_get(property, str, "");
+  memset(v, 255, 8);
+  for(int i = 0; i<len; i++) {
+    if(str[i] == '1') {
+      v[i/8] &= ~(1 << (i%8));
+    } else if(str[i] != '0') {
+      LOG_ERROR(LOG_TAG, "invalid characters in bitmask; skipping %c", str[i]);
+    }
+  }
+}
+
+static void filter_supported_feature(uint8_t *v) {
+  static int setup = 0;
+  static uint8_t unsupport_bitmask[8];
+  if(!setup) {
+    setup = 1;
+    setup_bitmask(unsupport_bitmask, "persist.sys.bt.unsupport.features");
+  }
+
+  for(unsigned i=0; i<sizeof(bt_device_features_t); i++)
+    v[i] &= unsupport_bitmask[i];
+}
+
 static void parse_read_local_extended_features_response(
     BT_HDR* response, uint8_t* page_number_ptr, uint8_t* max_page_number_ptr,
     bt_device_features_t* feature_pages, size_t feature_pages_count) {
@@ -123,6 +150,16 @@ static void parse_read_local_extended_features_response(
   STREAM_TO_ARRAY(feature_pages[*page_number_ptr].as_array, stream,
                   (int)sizeof(bt_device_features_t));
 
+  for (int i = 0; i < ((int)sizeof(bt_device_features_t)); i++)
+    LOG_DEBUG(LOG_TAG, "supported feature 0x%x is 0x%x", i, feature_pages[*page_number_ptr].as_array[i]);
+
+  filter_supported_feature(feature_pages[*page_number_ptr].as_array);
+
+  for (int i = 0; i < ((int)sizeof(bt_device_features_t)); i++)
+    LOG_DEBUG(LOG_TAG, "post-filtering supported feature 0x%x is 0x%x", i, feature_pages[*page_number_ptr].as_array[i]);
+
+  LOG_DEBUG(LOG_TAG, "supported_features array done");
+
   buffer_allocator->free(response);
 }
 
@@ -148,6 +185,19 @@ static void parse_ble_read_buffer_size_response(BT_HDR* response,
   buffer_allocator->free(response);
 }
 
+
+static void filter_supported_states(uint8_t *v, int size) {
+  static int setup = 0;
+  static uint8_t unsupport_bitmask[8];
+  if(!setup) {
+    setup = 1;
+    setup_bitmask(unsupport_bitmask, "persist.sys.bt.unsupport.states");
+  }
+
+  for(int i=0; i<size && i<8; i++)
+    v[i] &= unsupport_bitmask[i];
+}
+
 static void parse_ble_read_supported_states_response(
     BT_HDR* response, uint8_t* supported_states, size_t supported_states_size) {
   uint8_t* stream =
@@ -156,9 +206,30 @@ static void parse_ble_read_supported_states_response(
   CHECK(stream != NULL);
   STREAM_TO_ARRAY(supported_states, stream, (int)supported_states_size);
 
+  for (int i = 0; i < ((int)supported_states_size); i++)
+    LOG_DEBUG(LOG_TAG, "supported state 0x%x is 0x%x", i, supported_states[i]);
+
+  filter_supported_states(supported_states, supported_states_size);
+
+  for (int i = 0; i < ((int)supported_states_size); i++)
+    LOG_DEBUG(LOG_TAG, "supported.2 state 0x%x is 0x%x", i, supported_states[i]);
+
+  LOG_DEBUG(LOG_TAG, "supported_states array done");
   buffer_allocator->free(response);
 }
 
+static void filter_supported_stdfeatures(uint8_t *v) {
+  static int setup = 0;
+  static uint8_t unsupport_bitmask[8];
+  if(!setup) {
+    setup = 1;
+    setup_bitmask(unsupport_bitmask, "persist.sys.bt.unsupport.stdfeatures");
+  }
+
+  for(unsigned i=0; i<sizeof(bt_device_features_t); i++)
+    v[i] &= unsupport_bitmask[i];
+}
+
 static void parse_ble_read_local_supported_features_response(
     BT_HDR* response, bt_device_features_t* supported_features) {
   uint8_t* stream = read_command_complete_header(
@@ -168,6 +239,12 @@ static void parse_ble_read_local_supported_features_response(
   STREAM_TO_ARRAY(supported_features->as_array, stream,
                   (int)sizeof(bt_device_features_t));
 
+  for (int i = 0; i < ((int)sizeof(bt_device_features_t)); i++)
+    LOG_DEBUG(LOG_TAG, "supported state 0x%x is 0x%x", i, supported_features->as_array[i]);
+  filter_supported_stdfeatures(supported_features->as_array);
+  for (int i = 0; i < ((int)sizeof(bt_device_features_t)); i++)
+    LOG_DEBUG(LOG_TAG, "supported.2 state 0x%x is 0x%x", i, supported_features->as_array[i]);
+
   buffer_allocator->free(response);
 }
 
-- 
2.17.1