Use random tie-breaker value for ICE connectivity compatibility

.gitignore

@@ -1 +1,25 @@
-build
+# Build work directories (not the final artifacts)
+build/
+_build/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+
+# macOS
+.DS_Store
+._*
+
+# Unity
+**/Library/
+**/Logs/
+**/Temp/
+**/obj/
+**/UserSettings/
+*.csproj
+*.sln
+*.slnx
+mono_crash.*.json

BUILD.md

@@ -0,0 +1,147 @@
+# Building libpeer
+
+This document describes how to build libpeer, including the FAT library that combines all dependencies into a single static library.
+
+## Prerequisites
+
+- CMake 3.16 or higher
+- C compiler (GCC or Clang)
+- Git
+- Bash shell
+
+### Installing dependencies on Ubuntu/Debian
+
+```bash
+sudo apt -y install git cmake build-essential
+```
+
+### Installing dependencies on macOS
+
+```bash
+brew install cmake
+```
+
+## Clone the Repository
+
+Clone the repository with all submodules:
+
+```bash
+git clone --recursive git@github.com:dsugisawa-mixi/libpeer.git
+cd libpeer
+```
+
+If you already cloned without `--recursive`, initialize submodules:
+
+```bash
+git submodule update --init --recursive
+```
+
+## Build Steps
+
+### 1. Configure CMake
+
+```bash
+cmake -S . -B build
+```
+
+#### Build Options
+
+| Option | Default | Description |
+|--------|---------|-------------|
+| `ENABLE_TESTS` | OFF | Enable building tests |
+| `BUILD_SHARED_LIBS` | OFF | Build shared libraries |
+| `ADDRESS_SANITIZER` | OFF | Build with AddressSanitizer |
+| `MEMORY_SANITIZER` | OFF | Build with MemorySanitizer |
+| `THREAD_SANITIZER` | OFF | Build with ThreadSanitizer |
+| `UNDEFINED_BEHAVIOR_SANITIZER` | OFF | Build with UndefinedBehaviorSanitizer |
+
+
+### 2. Build the Project
+
+```bash
+cmake --build build
+```
+
+This will:
+- Build all third-party dependencies (mbedtls, libsrtp, usrsctp, cJSON)
+- Build the main `libpeer` library
+- Build the example applications
+
+### 3. Build the FAT Library
+
+The FAT library combines all static libraries into a single archive file, making it easier to link your application.
+
+```bash
+cmake --build build --target fat_library
+```
+
+The FAT library will be created at:
+
+```
+build/dist/lib/libpeer_fat.a
+```
+
+### Libraries Included in FAT Library
+
+The FAT library (`libpeer_fat.a`) includes:
+
+- `libpeer.a` - Main WebRTC library
+- `libusrsctp.a` - SCTP implementation for DataChannel
+- `libsrtp2.a` - Secure RTP
+- `libmbedtls.a` - TLS library
+- `libmbedx509.a` - X.509 certificate handling
+- `libmbedcrypto.a` - Cryptographic functions
+- `libcjson.a` - JSON parsing
+
+## Using the FAT Library
+
+Link against the FAT library in your project:
+
+```bash
+gcc -o myapp myapp.c -Ibuild/dist/include -Lbuild/dist/lib -lpeer_fat -lpthread
+```
+
+Or in CMake:
+
+```cmake
+add_executable(myapp myapp.c)
+target_include_directories(myapp PRIVATE ${LIBPEER_BUILD_DIR}/dist/include)
+target_link_libraries(myapp ${LIBPEER_BUILD_DIR}/dist/lib/libpeer_fat.a pthread)
+```
+
+## Cross-Compilation
+
+To cross-compile for another platform, specify a CMake toolchain file:
+
+```bash
+cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE=/path/to/toolchain.cmake
+cmake --build build
+cmake --build build --target fat_library
+```
+
+## Build Output Structure
+
+After building, the output directory structure is:
+
+```
+build/
+├── dist/
+│   ├── include/          # Header files
+│   │   ├── cjson/
+│   │   ├── mbedtls/
+│   │   ├── srtp2/
+│   │   └── usrsctp/
+│   └── lib/
+│       ├── libcjson.a
+│       ├── libmbedcrypto.a
+│       ├── libmbedtls.a
+│       ├── libmbedx509.a
+│       ├── libpeer_fat.a  # Combined FAT library
+│       ├── libsrtp2.a
+│       └── libusrsctp.a
+├── src/
+│   └── libpeer.a         # Main library
+└── examples/
+    └── generic/
+        └── sample        # Example application
+```

CMakeLists.txt

@@ -19,7 +19,7 @@ endif()
 project(peer)
 
 option(ENABLE_TESTS "Enable tests" OFF)
-option(BUILD_SHARED_LIBS "Build shared libraries" ON)
+option(BUILD_SHARED_LIBS "Build shared libraries" OFF)
 option(ADDRESS_SANITIZER "Build with AddressSanitizer." OFF)
 option(MEMORY_SANITIZER "Build with MemorySanitizer." OFF)
 option(THREAD_SANITIZER "Build with ThreadSanitizer." OFF)
@@ -72,6 +72,7 @@ ExternalProject_Add(cjson
   SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/cJSON
   CMAKE_ARGS
     -DCMAKE_C_FLAGS="-fPIC"
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5
     -DBUILD_SHARED_LIBS=off
     -DENABLE_CJSON_TEST=off
     -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/dist
@@ -81,7 +82,8 @@ ExternalProject_Add(cjson
 ExternalProject_Add(mbedtls
   SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/mbedtls
   CMAKE_ARGS
-    -DCMAKE_C_FLAGS="-fPIC"
+    -DCMAKE_C_FLAGS=-fPIC
+    -DMBEDTLS_FATAL_WARNINGS=off
     -DENABLE_TESTING=off
     -DENABLE_PROGRAMS=off
     -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/dist
@@ -104,7 +106,20 @@ ExternalProject_Add(usrsctp
   SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/usrsctp
   CMAKE_ARGS
     -DCMAKE_C_FLAGS="-fPIC"
+    -DCMAKE_POLICY_VERSION_MINIMUM=3.5
     -Dsctp_build_programs=off
     -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/dist
     -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
 )
+
+# FAT library target (combines all static libraries into one)
+set(FAT_LIB_NAME "libpeer_fat.a")
+set(FAT_LIB_PATH "${CMAKE_BINARY_DIR}/dist/lib/${FAT_LIB_NAME}")
+
+add_custom_target(fat_library
+  COMMAND bash ${CMAKE_CURRENT_SOURCE_DIR}/scripts/create_fat_library.sh
+    ${CMAKE_BINARY_DIR}
+    ${FAT_LIB_PATH}
+  DEPENDS peer
+  COMMENT "Creating FAT library: ${FAT_LIB_NAME}"
+)