Don't use transaction ID directly with apps

Problem: A client request is made up of a connection ID (bearer),
transaction ID (server assigned from native, so client can associate an
eventual accepted request with its response) and a handle (represents
the data being asked about). The domain used for the transaction ID is
local to the bearer in question. In GattService.java, we map the
transaction ID to a <connection ID, handle> pair, using it as a key,
assuming its unique across all devices and bearers when it is not. This
means that, in rare cases, transaction IDs can be overwritten, causing
data to go to the wrong bearer, or even the wrong device!

Solution: Instead of using transaction ID directly to identify a
request, add an extra layer of indirection in the form of an auto
incrementing integer which we'll refer to as a request ID in the handle
map. We'll now map a request ID to that requests _entire_ context, being
<connection Id, transaction Id, handle>, and send _that_ to the server
app to return with their response status and data. We can then use that
to look up the context and send our response to the correct bearer with
the correct transaction ID. Since each request the comes in gets a new
request ID, there's no squashing or stepping on values.

Flag: com.android.bluetooth.flags.gatt_multi_bearer_transactions
Bug: 418050422
Bug: 415380437
Test: atest com.android.bluetooth.gatt
Change-Id: Ifc033982e9f1a3c0c24741c4e8285572ca34c26e
4 files changed
tree: e2f55c44430288a38ba3e24662a9cf7cc4769adc
  1. android/
  2. apex/
  3. common/
  4. flags/
  5. floss/
  6. framework/
  7. offload/
  8. pandora/
  9. service/
  10. sysprop/
  11. system/
  12. tools/
  13. .clang-format
  14. .clang-tidy
  15. .editorconfig
  16. .gitignore
  17. .style.yapf
  18. Android.bp
  19. BluetoothGTestTemplate.xml
  20. BluetoothRustTestTemplate.xml
  21. BUILD.gn
  22. build.py
  23. Cargo.toml
  24. checkstyle.xml
  25. checkstyle_suppressions.xml
  26. CPPLINT.cfg
  27. METADATA
  28. MODULE_LICENSE_APACHE2
  29. NOTICE
  30. OWNERS
  31. OWNERS_automotive
  32. OWNERS_build
  33. OWNERS_channel_sounding
  34. OWNERS_chromeos
  35. OWNERS_content
  36. OWNERS_cs
  37. OWNERS_hearingaid
  38. OWNERS_leaudio
  39. PREUPLOAD.cfg
  40. pyproject.toml
  41. README.md
  42. rustfmt.toml
  43. TEST_MAPPING
README.md

Fluoride Bluetooth stack

Building and running on AOSP

Just build AOSP - Fluoride is there by default.

Building and running on Linux

Instructions for a Debian based distribution:

  • Debian Bullseye or newer
  • Ubuntu 20.10 or newer
  • Clang-11 or Clang-12
  • Flex 2.6.x
  • Bison 3.x.x (tested with 3.0.x, 3.2.x and 3.7.x)

You'll want to download some pre-requisite packages as well. If you're currently configured for AOSP development, you should have most required packages. Otherwise, you can use the following apt-get list or use the --run-bootstrap option on build.py (see below) to get a list of packages missing on your system:

sudo apt-get install repo git-core gnupg flex bison gperf build-essential \
  zip curl zlib1g-dev gcc-multilib g++-multilib \
  x11proto-core-dev libx11-dev libncurses5 \
  libgl1-mesa-dev libxml2-utils xsltproc unzip liblz4-tool libssl-dev \
  libc++-dev libevent-dev \
  flatbuffers-compiler libflatbuffers1 openssl \
  libflatbuffers-dev libfmt-dev libtinyxml2-dev \
  libglib2.0-dev libevent-dev libnss3-dev libdbus-1-dev \
  libprotobuf-dev ninja-build generate-ninja protobuf-compiler \
  libre2-9 debmake \
  llvm libc++abi-dev \
  libre2-dev libdouble-conversion-dev \
  libgtest-dev libgmock-dev libabsl-dev

You will also need a recent-ish version of Rust and Cargo. Please follow the instructions on Rustup to install a recent version.

Download source

mkdir ~/fluoride
cd ~/fluoride
git clone https://android.googlesource.com/platform/packages/modules/Bluetooth

Using --run-bootstrap on build.py

build.py is the helper script used to build Fluoride for Linux (i.e. Floss). It accepts a --run-bootstrap option that will set up your build staging directory and also make sure you have all required system packages to build (should work on Debian and Ubuntu). You will still need to build some unpackaged dependencies (like libchrome, modp_b64, googletest, etc).

To use it:

./build.py --run-bootstrap

This will install your bootstrapped build environment to ~/.floss. If you want to change this, just pass in --bootstrap-dir to the script.

Build dependencies

The following third-party dependencies are necessary but currently unavailable via a package manager. You may have to build these from source and install them to your local environment.

  • libchrome
  • modp_b64

We provide a script to produce debian packages for those components. Please see the instructions in build/dpkg/README.txt for more details.

cd system/build/dpkg
mkdir -p outdir/{modp_b64,libchrome}

# Build and install modp_b64
pushd modp_b64
./gen-src-pkg.sh $(readlink -f ../outdir/modp_b64)
popd
sudo dpkg -i outdir/modp_b64/*.deb

# Build and install libchrome
pushd libchrome
./gen-src-pkg.sh $(readlink -f ../outdir/libchrome)
popd
sudo dpkg -i outdir/libchrome/*.deb

Rust dependencies

Note: Handled by --run-bootstrap option.

Run the following to install Rust dependencies:

cargo install cxxbridge-cmd

Stage your build environment

Note: Handled by --run-bootstrap option.

For host build, we depend on a few other repositories:

Clone these all somewhere and create your staging environment.

export STAGING_DIR=path/to/your/staging/dir
mkdir ${STAGING_DIR}
mkdir -p ${STAGING_DIR}/external
ln -s $(readlink -f ${PLATFORM2_DIR}/common-mk) ${STAGING_DIR}/common-mk
ln -s $(readlink -f ${PLATFORM2_DIR}/.gn) ${STAGING_DIR}/.gn
ln -s $(readlink -f ${RUST_CRATE_DIR}) ${STAGING_DIR}/external/rust
ln -s $(readlink -f ${PROTO_LOG_DIR}) ${STAGING_DIR}/external/proto_logging

Build

We provide a build script to automate building assuming you've staged your build environment already as above. At this point, make sure you have all the pre-requisites installed (i.e. bootstrap option and other dependencies above) or you will see failures. In addition, you may need to set a --libdir= if your libraries are not stored in /usr/lib by default.

./build.py

This will build all targets to the output directory at --bootstrap-dir (which defaults to ~/.floss). You can also build each stage separately (if you want to iterate on something specific):

  • prepare - Generate the GN rules
  • tools - Generate host tools
  • rust - Build the rust portion of the build
  • main - Build all the C/C++ code
  • test - Build all targets and run the tests
  • clean - Clean the output directory

You can choose to run only a specific stage by passing an arg via --target.

Currently, Rust builds are a separate stage that uses Cargo to build. See gd/rust/README.md for more information. If you are iterating on Rust code and want to add new crates, you may also want to use the --no-vendored-rust option (which will let you use crates.io instead of using a pre-populated vendored crates repo).

Run

By default on Linux, we statically link libbluetooth so you can just run the binary directly. By default, it will try to run on hci0 but you can pass it --hci=N, where N corresponds to /sys/class/bluetooth/hciN.

$OUTPUT_DIR/debug/btadapterd --hci=$HCI INIT_gd_hci=true